Thermal Degradation Study

*Analytical Pyrolysis*

2015;**81**:322-338

2018;**13**(7):e0199422

2015;**12**:391-404

2006;**77**:169-176

2017;**3**:63

of the lignin from sugarcane bagasse and straw. Biomass and Bioenergy.

[77] Berhanu H, Kiflie Z, Miranda I, Lourenço A, Ferreira J, Feleke S, et al. Characterization of crop residues from false banana/*Enset ventricosum*/ in Ethiopia in view of full-resource valorization. PLoS One.

[78] Sen A, Pereira H, Olivella MA, Villaescusa I. Heavy metals removal in aqueous environments using bark as a biosorbent. International Journal of Environmental Science and Technology.

[79] Leite C, Pereira H. Cork-containing barks—A review. Frontiers in Materials.

[80] Marques AV, Pereira H, Rodrigues J,

Meier D, Faix O. Isolation and comparative characterisation of a Bjӧrkman lignin from the saponified cork of Douglas-fir bark. Journal of Analytical and Applied Pyrolysis.

[81] Ohra-aho T, Tenkanen M,

Tamminen T. Direct analysis of lignin and lignin-like components from softwood kraft pulp by Py-GC/MS techniques. Journal of Analytical and Applied Pyrolysis. 2005;**74**:123-128

[82] Lourenço A, Gominho J, Marques AV, Pereira H. Reactivity of syringyl and guaiacyl lignin units and delignification kinetics in the kraft pulping of *Eucalyptus globulus* wood using Py-GC-MS/FID. Bioresource Technology. 2012;**123**:296-302

**30**

Chapter 3

Abstract

1. Introduction

33

and reduce the waste of timber [7–9].

Release Profile of Nitrogen during

Thermal Treatment of Waste

Wooden Packaging Materials

Keywords: pyrolysis, fixed bed, Py-GC/MS, particle board, bio-oil

Jianmin Chang and Jinsheng Gou

Liuming Song, Xiao Ge, Xueyong Ren, Wenliang Wang,

In this paper, the fast pyrolysis experiment of particle board was carried out on a fixed bed reactor and a Py-GC/MS equipment. The effects of temperature and gas phase residence time on the product yields and its components distribution were investigated. The effect of components of particle board on product yields and its components distribution was also investigated. The results showed that the temperature has a great influence on the yields of fast pyrolysis products, and the yield of pyrolysis oil reached the highest at 550°C. The urea-formaldehyde resin would prevent the pyrolysis of particle board. Compared with the bio-oil from fast pyrolysis of wood, the major components of the bio-oil from fast pyrolysis of particle board did not change much.

The world concerns about environmental pollution caused by fossil fuel combustion and exhaustion of energy resources have drawn significant attention to researchers. Biomass can be converted into various fuels and chemicals by different methods to replace petrochemical fuels [1–3]. Fast pyrolysis of biomass is one of the most promising and fast developing biomass thermochemical conversion technologies, which can turn organic materials into high value products such as chemical products or liquid fuels. And this technology has been widely used in the field of biomass renewable utilization in recent years [4–6]. This transformation into an environment-friendly renewable energy sources can replace the fossil fuels consumed and reduce greenhouse gas emissions. Among the biomass, the large amount of waste wood has attracted increasing attention because it can be used as an energy

Particle boards occupy a large proportion of waste wood, so how to effectively

convert it into high value chemical products has attracted the attention of researchers. Choi et al. [3] conducted fast pyrolysis of particle board over three types of zeolite catalysts, the results showed that the bio-oil yield and gas yield in catalytic pyrolysis was lower and higher than those in non-catalytic pyrolysis, respectively. Park et al. [10] also examined the catalytic pyrolysis of particle board

using a nanoporous catalyst and showed that bio-oil is composed mainly of

#### Chapter 3

## Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

Liuming Song, Xiao Ge, Xueyong Ren, Wenliang Wang, Jianmin Chang and Jinsheng Gou

#### Abstract

In this paper, the fast pyrolysis experiment of particle board was carried out on a fixed bed reactor and a Py-GC/MS equipment. The effects of temperature and gas phase residence time on the product yields and its components distribution were investigated. The effect of components of particle board on product yields and its components distribution was also investigated. The results showed that the temperature has a great influence on the yields of fast pyrolysis products, and the yield of pyrolysis oil reached the highest at 550°C. The urea-formaldehyde resin would prevent the pyrolysis of particle board. Compared with the bio-oil from fast pyrolysis of wood, the major components of the bio-oil from fast pyrolysis of particle board did not change much.

Keywords: pyrolysis, fixed bed, Py-GC/MS, particle board, bio-oil

#### 1. Introduction

The world concerns about environmental pollution caused by fossil fuel combustion and exhaustion of energy resources have drawn significant attention to researchers. Biomass can be converted into various fuels and chemicals by different methods to replace petrochemical fuels [1–3]. Fast pyrolysis of biomass is one of the most promising and fast developing biomass thermochemical conversion technologies, which can turn organic materials into high value products such as chemical products or liquid fuels. And this technology has been widely used in the field of biomass renewable utilization in recent years [4–6]. This transformation into an environment-friendly renewable energy sources can replace the fossil fuels consumed and reduce greenhouse gas emissions. Among the biomass, the large amount of waste wood has attracted increasing attention because it can be used as an energy and reduce the waste of timber [7–9].

Particle boards occupy a large proportion of waste wood, so how to effectively convert it into high value chemical products has attracted the attention of researchers. Choi et al. [3] conducted fast pyrolysis of particle board over three types of zeolite catalysts, the results showed that the bio-oil yield and gas yield in catalytic pyrolysis was lower and higher than those in non-catalytic pyrolysis, respectively. Park et al. [10] also examined the catalytic pyrolysis of particle board using a nanoporous catalyst and showed that bio-oil is composed mainly of

oxygenates, phenolics and acids, with smaller amounts of aromatics and hydrocarbons. Lee et al. [11] investigated the co-pyrolysis of waste particle board and polypropylene over four types of catalysts, they found that catalytic co-pyrolysis suppressed the formation of PAHs, and the quality of bio-oil has improved. When the particle board was combined with other materials for co-pyrolysis, or when the particle board was pyrolyzed over different catalysts, high quality bio-oil or aromatic products could be obtained [8, 11–13].

When only the particle board was pyrolyzed, many researchers have found that temperature was the most important factor to determine the yields of bio-oil and gas products. Most scholars have only studied the influence of temperature on the pyrolysis characteristics of wood and particleboard, and there are few literatures concerning the influence of other conditions on the pyrolysis characteristics of wood and particle board. In this paper, fast pyrolysis experiments were carried out in fixed bed reactor and a Py-GC/MS equipment, and the effects of temperature and gas phase residence time on the product yields and its components distribution were investigated. The effect of components of particle board on product yields and its components distribution was also investigated.

#### 2. Materials and methods

#### 2.1 Experimental materials and characteristics analysis

#### 2.1.1 Experimental materials

The experimental samples selected for this study included two types of solid wood, a wood adhesive, and six types of particle board.

Two types of solid wood, Larch wood (Larix gmelinii (Rupr.) Rupr.) and Poplar wood (Populus deltoides), which are the most commonly used for the production of wood based panel, were selected. Larch wood and Poplar wood were obtained from the north of Daxinganling, Inner Mongolia, the age of the trees was around 30 and 10 years respectively. Larch wood and Poplar wood were marked with "Larch" and "Poplar" respectively.

Urea formaldehyde (UF) is the most commonly used adhesive in the wood based panel industry. Provided by Beijing Taier Chemical Co., Ltd., its F/U molar ratio is 1.1 and the solids content is 53%.

PBL: Larch Particle Board and PBP: Poplar Particle Board. The adhesive levels used for preparing particle boards were 5%, 10%, and 20%, respectively.

The particle board was made in our laboratory (width: 400 400 mm, thickness: 10mm). There was a certain difference between self-made particle board and actual waste particle board, but there were uncertainties in the waste time, wood types, adhesive types and content, etc., which were actually unfavorable for research and analysis of results. Therefore, the particle board was placed in a room under controlled environment for 6 months after preparation to simulate the waste particle board in nature.

Elemental analysis of raw materials was performed using the VarioEL elemental analyzer at the Analytical Center of Changchun Institute of Chemicals, Chinese Academy of Sciences. The analysis was conducted in accordance with the International "Method for Analysis of Carbon, Hydrogen, and Oxygen in Rock Organic Matter" (GB/T 19143-2003), where C, H, and N elements were tested experimentally and the final results were averaged twice for the experiment. The O element

Holocellulose %

Larch 42.76 20.79 63.55 24.03 4.90 0.905 3.26 Poplar 45.87 28.44 74.31 19.12 5.01 1.169 5.89

Lignin %

pH Ash %

Benzol extractive %

Sample<sup>a</sup> C% H% O%<sup>b</sup> N% Larch 46.15 6.31 47.36 0.12 Poplar 45.24 6.30 48.36 0.10 UF 33.45 5.02 29.31 32.22 PBL (10% sizing amount) 44.15 6.11 46.28 3.46 PBP (10% sizing amount) 43.35 5.96 47.55 3.14

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

Sample<sup>a</sup> M% A% V% FC% Larch 7.26 1.78 73.12 17.84 Poplar 6.79 1.81 72.51 18.89 UF 2.18 0.53 95.98 1.31 PBL 6.04 1.68 73.43 18.85 PBP 6.37 1.57 73.01 19.05

The industrial analysis was completed at the Chemical Laboratory of Beijing Forestry University, and conducted according to the national standard "Test Methods for Charcoal and Charcoal" (GB/T17664-1999). From Table 2, it can be concluded that the ash content of Poplar was larger than that of Larch, and the volatile content of particle board and solid wood was equivalent, while the volatile content of UF resin was much higher than that of solid wood and particle board, but the fixed carbon of particle board was higher than solid

content was obtained by subtraction.

wood and UF resin.

35

a

b

Table 1.

The test result was an air-drying base.

Element analysis of samples (wt%).

Sample<sup>a</sup> Cellulose

a

a

Table 2.

b

Table 3.

%

The test result was an air-drying base.

Proximate analysis of samples (wt%).

The test result was an air-drying base

Component analysis of samples.

The hemicellulose value was obtained by subtraction.

Hemicellulose %b

The oxygen value was obtained by subtraction.

DOI: http://dx.doi.org/10.5772/intechopen.81522

#### 2.1.2 Characteristic analysis

The materials of solid wood and particle board were crushed, sieved and dried before the experiment. After the adhesive was dried and solidified in the oven, it was crushed and sieved, all materials have a particle size of about 1 mm. Elemental analysis, industrial analysis and component analysis of raw materials are shown in Tables 1–3, respectively.

#### Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522


a The test result was an air-drying base.

b The oxygen value was obtained by subtraction.

#### Table 1.

oxygenates, phenolics and acids, with smaller amounts of aromatics and hydrocarbons. Lee et al. [11] investigated the co-pyrolysis of waste particle board and polypropylene over four types of catalysts, they found that catalytic co-pyrolysis suppressed the formation of PAHs, and the quality of bio-oil has improved. When the particle board was combined with other materials for co-pyrolysis, or when the particle board was pyrolyzed over different catalysts, high quality bio-oil or aro-

When only the particle board was pyrolyzed, many researchers have found that temperature was the most important factor to determine the yields of bio-oil and gas products. Most scholars have only studied the influence of temperature on the pyrolysis characteristics of wood and particleboard, and there are few literatures concerning the influence of other conditions on the pyrolysis characteristics of wood and particle board. In this paper, fast pyrolysis experiments were carried out in fixed bed reactor and a Py-GC/MS equipment, and the effects of temperature and gas phase residence time on the product yields and its components distribution were investigated. The effect of components of particle board on product yields and

The experimental samples selected for this study included two types of solid

Two types of solid wood, Larch wood (Larix gmelinii (Rupr.) Rupr.) and Poplar wood (Populus deltoides), which are the most commonly used for the production of wood based panel, were selected. Larch wood and Poplar wood were obtained from the north of Daxinganling, Inner Mongolia, the age of the trees was around 30 and 10 years respectively. Larch wood and Poplar wood were marked with "Larch" and

Urea formaldehyde (UF) is the most commonly used adhesive in the wood based panel industry. Provided by Beijing Taier Chemical Co., Ltd., its F/U molar ratio is

PBL: Larch Particle Board and PBP: Poplar Particle Board. The adhesive levels

The particle board was made in our laboratory (width: 400 400 mm, thickness: 10mm). There was a certain difference between self-made particle board and actual waste particle board, but there were uncertainties in the waste time, wood types, adhesive types and content, etc., which were actually unfavorable for research and analysis of results. Therefore, the particle board was placed in a room under controlled environment for 6 months after preparation to simulate the waste

The materials of solid wood and particle board were crushed, sieved and dried before the experiment. After the adhesive was dried and solidified in the oven, it was crushed and sieved, all materials have a particle size of about 1 mm. Elemental analysis, industrial analysis and component analysis of raw materials are shown in

used for preparing particle boards were 5%, 10%, and 20%, respectively.

matic products could be obtained [8, 11–13].

its components distribution was also investigated.

2.1 Experimental materials and characteristics analysis

wood, a wood adhesive, and six types of particle board.

2. Materials and methods

Analytical Pyrolysis

2.1.1 Experimental materials

"Poplar" respectively.

particle board in nature.

2.1.2 Characteristic analysis

Tables 1–3, respectively.

34

1.1 and the solids content is 53%.

Element analysis of samples (wt%).


The test result was an air-drying base.

#### Table 2.

Proximate analysis of samples (wt%).


a The test result was an air-drying base

b The hemicellulose value was obtained by subtraction.

#### Table 3.

Component analysis of samples.

Elemental analysis of raw materials was performed using the VarioEL elemental analyzer at the Analytical Center of Changchun Institute of Chemicals, Chinese Academy of Sciences. The analysis was conducted in accordance with the International "Method for Analysis of Carbon, Hydrogen, and Oxygen in Rock Organic Matter" (GB/T 19143-2003), where C, H, and N elements were tested experimentally and the final results were averaged twice for the experiment. The O element content was obtained by subtraction.

The industrial analysis was completed at the Chemical Laboratory of Beijing Forestry University, and conducted according to the national standard "Test Methods for Charcoal and Charcoal" (GB/T17664-1999). From Table 2, it can be concluded that the ash content of Poplar was larger than that of Larch, and the volatile content of particle board and solid wood was equivalent, while the volatile content of UF resin was much higher than that of solid wood and particle board, but the fixed carbon of particle board was higher than solid wood and UF resin.

The chemical composition analysis was performed in the Bio-oil Adhesives Laboratory at Beijing Forestry University. The raw material preparation was performed in accordance with the national standard, "Analysis of Samples for Papermaking Raw Material Analysis" (GB/T 2677.1-93). The lignin content was determined according to the national standard "Determination of Acid-insoluble Lignin in Papermaking Raw Materials" (GB/T 2677.8-94), the cellulose content was extracted by nitric acid ethanol method, and the holocellulose content was determined according to the national standard "Determination of Holocellulose Content of Papermaking Raw Materials" (GB/T 2677.10-1995). The lignin content of Larch was higher than that of Poplar from Table 3, while the Poplar content of cellulose and hemicellulose was higher than that of Larch.

uniform feeding of small amount of materials (less than 5 g). The pyrolysis system consisted of an automatic temperature-controlled electric heating furnace, a quartz tube reactor and a pipe end interface. The fixed-bed reactor was a quartz tube with an inner diameter of 20mm and a length of 500 mm, a quartz sintered plate was set in the middle of the tube to filter pyrolytic carbon produced by pyrolysis, both ends of the quartz tube were special metal quick connectors for convenient installation and removal, connected with stainless steel pipe through quick connector. The product absorption system consisted of a two-stage ice-water bath condensing tube, and an exhaust gas collection bag

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

The requirement of temperature for fast pyrolysis is 400600°C [1, 14–15]. In this paper, in order to explore the pyrolysis characteristics of temperature and the nitrogen release mechanism of the particle board, four pyrolysis temperatures were

The requirement for the gas phase residence time of the fast pyrolysis process is 3–0.1 s [1, 14, 15], in order to investigate the influence of gas-phase residence time on the pyrolysis characteristics and nitrogen release mechanism of particle board, three gas-phase residence time were set in the research process, which were 3, 1 and 0.5 s respectively. Considering that the gas phase residence time was controlled by the flow rate of the carrier gas during the actual experiment, the relationship between the gas flow rate and the gas phase residence time at different pyrolysis temperatures was calculated before the formal experiment, the

The temperature of the heating furnace was first determined during the experiment, and the pyrolysis system will stably maintained at the pyrolysis temperatures; then, the prepared feedstock was loaded into the feeding bag; open the intake system valve at a predetermined flow rate and began to purge the entire experimental pipeline with high-purity nitrogen to obtain the inert environment. After the temperature of the pyrolysis system was stabilized to the pyrolysis temperature, the feedstock particle slowly entered the injection line through the vibration feed tube, the material which fell into the injection line entrained by the carrier gas into the quartz tube reactor for fast pyrolysis reactions. The pyrolysisgenerated volatiles and pyrolytic carbons entered the gas absorption and metering system with the carrier gas after being filtered by the sintered plate in the center of the quartz tube and the filter quartz wool placed at the end of the reactor pipeline. Pyrolytic carbon remaining in the reactor was collected after pyrolysis

The calculation of fast pyrolysis gas yield was converted into weight fraction after metering volume by flowmeter, the fast pyrolysis carbon yield was calculated by direct weighing, and the fast pyrolysis oil yield was obtained by subtraction method. In a typical experiment run, the feeding amount was 3 g, and the reaction temperatures of the fixed-bed quartz tube were 450, 500, 550, and 600°C respec-

2.2.2 Pyrolysis gas chromatography combined experimental device and method

phy coupled with mass spectrometry analysis system. The cracking system

The Py-GC/MS equipment included a cracking system and a gas chromatogra-

consisted of a CDS5150 fast thermal cracker, which was equipped with injection and gas loading supply system manufactured by CDS, USA. The gas chromatography

/h, respectively.

/h respectively, and the

coupled with a volume flow meter.

DOI: http://dx.doi.org/10.5772/intechopen.81522

was completed.

37

pyrolysis time was 5 min.

selected, which were 450, 500, 550 and 600°C, respectively.

corresponding carrier gas flow rate was 0.1, 0.16, and 0.3 m<sup>3</sup>

tively, the carrier gas flow rates were 0.1, 0.16, and 0.3 m<sup>3</sup>

#### 2.2 Experimental devices and methods

In this article, two devices were used to discuss the fast pyrolysis characteristics of waste particle board. One was a fixed bed fast pyrolysis device (fixed-bed reactor), and the other was a Py-GC/MS equipment. The yields of product were obtained from the fast pyrolysis experiments which were carried out on the fixed bed reactor. The distribution of components in the liquid phase products and the distribution of nitrogen were analyzed by Py-GC/MS equipment.

#### 2.2.1 Fixed bed reactor and experimental method

In this paper, a set of experimental apparatus for fast pyrolysis of small gas entrainment fixed bed was designed, precise automatic temperature control and extremely short gas phase residence time could be achieved through the device. The whole device consisted of gas supply system, sampling system, pyrolysis system, product absorption and measurement system. The schematic diagram of the experimental device is shown in Figure 1.

The gas supply system consisted of nitrogen cylinder, flow meter and threeway valve, etc. Nitrogen cylinder was equipped with safety valve and the nitrogen gas purity was 99.999%. The sampling system consisted of a feeding pipeline and a vibrating feeding device, which allows the continuous and

Figure 1. Schematic of (a) fixed bed fast pyrolysis reactor with carry gas feeding module, and (b) Py-GC/MS.

#### Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

uniform feeding of small amount of materials (less than 5 g). The pyrolysis system consisted of an automatic temperature-controlled electric heating furnace, a quartz tube reactor and a pipe end interface. The fixed-bed reactor was a quartz tube with an inner diameter of 20mm and a length of 500 mm, a quartz sintered plate was set in the middle of the tube to filter pyrolytic carbon produced by pyrolysis, both ends of the quartz tube were special metal quick connectors for convenient installation and removal, connected with stainless steel pipe through quick connector. The product absorption system consisted of a two-stage ice-water bath condensing tube, and an exhaust gas collection bag coupled with a volume flow meter.

The requirement of temperature for fast pyrolysis is 400600°C [1, 14–15]. In this paper, in order to explore the pyrolysis characteristics of temperature and the nitrogen release mechanism of the particle board, four pyrolysis temperatures were selected, which were 450, 500, 550 and 600°C, respectively.

The requirement for the gas phase residence time of the fast pyrolysis process is 3–0.1 s [1, 14, 15], in order to investigate the influence of gas-phase residence time on the pyrolysis characteristics and nitrogen release mechanism of particle board, three gas-phase residence time were set in the research process, which were 3, 1 and 0.5 s respectively. Considering that the gas phase residence time was controlled by the flow rate of the carrier gas during the actual experiment, the relationship between the gas flow rate and the gas phase residence time at different pyrolysis temperatures was calculated before the formal experiment, the corresponding carrier gas flow rate was 0.1, 0.16, and 0.3 m<sup>3</sup> /h, respectively.

The temperature of the heating furnace was first determined during the experiment, and the pyrolysis system will stably maintained at the pyrolysis temperatures; then, the prepared feedstock was loaded into the feeding bag; open the intake system valve at a predetermined flow rate and began to purge the entire experimental pipeline with high-purity nitrogen to obtain the inert environment. After the temperature of the pyrolysis system was stabilized to the pyrolysis temperature, the feedstock particle slowly entered the injection line through the vibration feed tube, the material which fell into the injection line entrained by the carrier gas into the quartz tube reactor for fast pyrolysis reactions. The pyrolysisgenerated volatiles and pyrolytic carbons entered the gas absorption and metering system with the carrier gas after being filtered by the sintered plate in the center of the quartz tube and the filter quartz wool placed at the end of the reactor pipeline. Pyrolytic carbon remaining in the reactor was collected after pyrolysis was completed.

The calculation of fast pyrolysis gas yield was converted into weight fraction after metering volume by flowmeter, the fast pyrolysis carbon yield was calculated by direct weighing, and the fast pyrolysis oil yield was obtained by subtraction method. In a typical experiment run, the feeding amount was 3 g, and the reaction temperatures of the fixed-bed quartz tube were 450, 500, 550, and 600°C respectively, the carrier gas flow rates were 0.1, 0.16, and 0.3 m<sup>3</sup> /h respectively, and the pyrolysis time was 5 min.

#### 2.2.2 Pyrolysis gas chromatography combined experimental device and method

The Py-GC/MS equipment included a cracking system and a gas chromatography coupled with mass spectrometry analysis system. The cracking system consisted of a CDS5150 fast thermal cracker, which was equipped with injection and gas loading supply system manufactured by CDS, USA. The gas chromatography

The chemical composition analysis was performed in the Bio-oil Adhesives Laboratory at Beijing Forestry University. The raw material preparation was performed in accordance with the national standard, "Analysis of Samples for Papermaking Raw Material Analysis" (GB/T 2677.1-93). The lignin content was determined according to the national standard "Determination of Acid-insoluble Lignin in Papermaking Raw Materials" (GB/T 2677.8-94), the cellulose content was extracted by nitric acid ethanol method, and the holocellulose content was determined according to the national standard "Determination of Holocellulose Content of Papermaking Raw Materials" (GB/T 2677.10-1995). The lignin content of Larch was higher than that of Poplar from Table 3, while the Poplar content of

In this article, two devices were used to discuss the fast pyrolysis characteristics of waste particle board. One was a fixed bed fast pyrolysis device (fixed-bed reactor), and the other was a Py-GC/MS equipment. The yields of product were obtained from the fast pyrolysis experiments which were carried out on the fixed bed reactor. The distribution of components in the liquid phase products and the distribution of nitrogen were analyzed by Py-GC/MS

In this paper, a set of experimental apparatus for fast pyrolysis of small gas entrainment fixed bed was designed, precise automatic temperature control and extremely short gas phase residence time could be achieved through the device. The whole device consisted of gas supply system, sampling system, pyrolysis system, product absorption and measurement system. The schematic diagram of the exper-

The gas supply system consisted of nitrogen cylinder, flow meter and three-

way valve, etc. Nitrogen cylinder was equipped with safety valve and the nitrogen gas purity was 99.999%. The sampling system consisted of a feeding pipeline and a vibrating feeding device, which allows the continuous and

Schematic of (a) fixed bed fast pyrolysis reactor with carry gas feeding module, and (b) Py-GC/MS.

cellulose and hemicellulose was higher than that of Larch.

2.2 Experimental devices and methods

2.2.1 Fixed bed reactor and experimental method

imental device is shown in Figure 1.

equipment.

Analytical Pyrolysis

Figure 1.

36

mass spectrometry analysis system consisted of a Shimadzu GCMS-QP2010Plus GC/MS analysis manufactured by Shimadzu Corporation of Japan. The pyrolysis system and the gas chromatograph mass spectrometry system were connected by a special insulation connecting pipeline, the chromatographic column was M-5 (60 m 0.25 mm 0.25 μm). The schematic diagram of the experimental device is shown in Figure 1.

3. Results and discussion

Figure 2.

39

product of waste particle board

DOI: http://dx.doi.org/10.5772/intechopen.81522

3.1 Influence of pyrolysis conditions on the yields of fast pyrolysis

Figure 2 shows the yields of fast pyrolysis products of UF resin, two types of wood and particle board at different temperatures. As can be seen from the figure, the effect of temperature on the pyrolysis products of raw materials was basically the same in the experimental temperature range. Wood mainly consists of cellulose, hemicellulose and lignin, and therefore its pyrolysis behavior can be considered to be the sum of the behaviors of these three components [16]. The pyrolysis products contain such substances as CO, CO2, H2, CH4, C2H4, amine, alcohol, phenol, acid, ketone, sugar, aldehyde, ester, ether, hydrocarbon and heterocyclic. As the temperature rise, the yields of gas product gradually increased, and the rising tendency became more pronounced when the temperature exceeded 550°C. The yields of pyrolytic carbon gradually decreased with the increase of temperature, when the temperature exceeded 550° C, the downward trend tended to be gentle. The yields of pyrolysis oil increased and then decreased with the increase of temperature, which reached a maximum at 550°C. During the pyrolysis process, the carbonization reaction dominated at a lower temperature, and the volatilization was insufficient. At a higher temperature condition, the cracking reaction intensified, a large number of condensable volatiles precipitated, the yield of pyrolysis oil increased subsequently, and the output of pyrolytic carbon decreased. At 600°C, the secondary cracking in the reaction system will gradually strengthen while the components in the condensable volatiles undergo secondary cracking, resulting in the formation of small molecules of non-condensable gases. The sugars, alcohols, ketones and acids in tar contain functional groups such as hydroxyl

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

Yields of products from fast pyrolysis at different temperature of (a) Larch, (b) Poplar, (c) UF, (d) PBL, and (e) PBP.

3.1.1 Effect of temperature on yields of fast pyrolysis product

During the experiment, accurately weighed raw materials and a little amount of quartz fiber were placed in the quartz tube of the CDS5150 cracker. The pyrolyzer was purged with high-purity nitrogen as the carrier gas, pyrolyzed at the determined heating rate, pyrolysis time, and pyrolysis temperature, and the product was analyzed online by GC/MS. The spectra obtained for each test were analyzed using the system's software. The NIST library was used to record the product's absolute peak area and relative peak area.

When using the NIST library for analysis, most of the peaks could be identified and confirmed, but there were also a small number of peaks that could not be determined (the degree of similarity between the library and the standard material provided by the library was too low). Therefore, the sum of the relative peak area content determined by GC/MS in the relevant experimental results was less than 100%. The part where the sum did not reach 100% was the unknown product, but this part was very small and was represented by other classes in the result analysis.

The Py-GC/MS experimental conditions and instrument parameter settings are shown in Table 4.


#### Table 4.

Conditions and parameters for Py-GC/MS experiments.

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

#### 3. Results and discussion

mass spectrometry analysis system consisted of a Shimadzu GCMS-QP2010Plus GC/MS analysis manufactured by Shimadzu Corporation of Japan. The pyrolysis system and the gas chromatograph mass spectrometry system were connected by a special insulation connecting pipeline, the chromatographic column was M-5 (60 m 0.25 mm 0.25 μm). The schematic diagram of the experimental device is

During the experiment, accurately weighed raw materials and a little amount of quartz fiber were placed in the quartz tube of the CDS5150 cracker. The pyrolyzer was purged with high-purity nitrogen as the carrier gas, pyrolyzed at the determined heating rate, pyrolysis time, and pyrolysis temperature, and the product was analyzed online by GC/MS. The spectra obtained for each test were analyzed using the system's software. The NIST library was used to record the product's absolute

When using the NIST library for analysis, most of the peaks could be identified

400, 500, 600°C

280°C

50°C constant temperature 5 min, warm up to 280°C at 10°C/min, constant temperature 15 min

280°C

250°C

70 eV

SCAN

and confirmed, but there were also a small number of peaks that could not be determined (the degree of similarity between the library and the standard material provided by the library was too low). Therefore, the sum of the relative peak area content determined by GC/MS in the relevant experimental results was less than 100%. The part where the sum did not reach 100% was the unknown product, but this part was very small and was represented by other classes in the result analysis. The Py-GC/MS experimental conditions and instrument parameter settings are

> Cracking time 15 s Gas flow 100, 50, 10 ml/min

Gas loading He Gas flow rate 1.0 ml/min Split ratio 100:1

Scan range (20–450) u

Parameter name Setting value Cracking conditions Heating rate 20°C/ms

> Pyrolysis temperature

> Inlet temperature

Heating program

Interface temperature

Ion source temperature

EI source electron energy

Scanning method

Conditions and parameters for Py-GC/MS experiments.

shown in Figure 1.

Analytical Pyrolysis

shown in Table 4.

Gas

chromatographic conditions

Mass spectrometry conditions

Table 4.

38

peak area and relative peak area.

#### 3.1 Influence of pyrolysis conditions on the yields of fast pyrolysis product of waste particle board

#### 3.1.1 Effect of temperature on yields of fast pyrolysis product

Figure 2 shows the yields of fast pyrolysis products of UF resin, two types of wood and particle board at different temperatures. As can be seen from the figure, the effect of temperature on the pyrolysis products of raw materials was basically the same in the experimental temperature range. Wood mainly consists of cellulose, hemicellulose and lignin, and therefore its pyrolysis behavior can be considered to be the sum of the behaviors of these three components [16]. The pyrolysis products contain such substances as CO, CO2, H2, CH4, C2H4, amine, alcohol, phenol, acid, ketone, sugar, aldehyde, ester, ether, hydrocarbon and heterocyclic. As the temperature rise, the yields of gas product gradually increased, and the rising tendency became more pronounced when the temperature exceeded 550°C. The yields of pyrolytic carbon gradually decreased with the increase of temperature, when the temperature exceeded 550° C, the downward trend tended to be gentle. The yields of pyrolysis oil increased and then decreased with the increase of temperature, which reached a maximum at 550°C. During the pyrolysis process, the carbonization reaction dominated at a lower temperature, and the volatilization was insufficient. At a higher temperature condition, the cracking reaction intensified, a large number of condensable volatiles precipitated, the yield of pyrolysis oil increased subsequently, and the output of pyrolytic carbon decreased. At 600°C, the secondary cracking in the reaction system will gradually strengthen while the components in the condensable volatiles undergo secondary cracking, resulting in the formation of small molecules of non-condensable gases. The sugars, alcohols, ketones and acids in tar contain functional groups such as hydroxyl

and carboxyl groups, with the increase of temperature, these functional groups will decompose and produce gases such as CO and CO2, resulting in the increase of gas phase products, which in turn reduced the yield of pyrolysis oil. During wood pyrolysis, lignin produces more fixed carbon than cellulose and hemicellulose, so the char yield of Larch and Poplar is higher than that of UF resin. Because the structure of UF resin is not complicated with wood, the yield change of UF resin in the pyrolysis process is not as obvious as that of wood and particle board, and the products are relatively few, mainly ester and amine substances [16].

pyrolysis carbon of PBL is higher than that of Larch, and it can be inferred that UF resin will prevent the pyrolysis of the particle board at high temperatures. As the temperature rises, this inhibition slows down, at 450°C, particle board fast pyrolysis carbon is 3% higher than Larch, while the pyrolytic carbon from particle board is only 1% higher than that from Larch when the temperature reaches 600°C. The yield of pyrolysis oil from fast pyrolysis of particle board is basically the same as the yield from Larch at 450°C, and the former is less than later when the temperature setting at 500 and 550°C. However, when the temperature exceeds 600°C, the yield of pyrolysis oil from fast pyrolysis of particle board is less than that from Larch. This is because the yield of pyrolysis oil of UF resin is high than that of wood, which resulted in the superposition effect; and on the other hand, it also shows that the introduction of UF resin has an impact on the yield of pyrolysis oil, which is more sensitive to temperature. From Figure 4, it can be seen that the effect of UF resin on the yield of fast pyrolysis products of PBP is similar to that of PBL, which has an inhibitory effect on the pyrolysis process of the particle board, and increases the yield of pyrolytic carbon of the particle board, along with the temperature increased this inhibition slows down. Figure 5 shows the content comparison diagram of Tar and Char in the fast pyrolysis products from different materials. As can be seen from the figure, the Tar yield of the UF resin is significantly higher than that of other raw materials, and the Tar yield is higher at 550°C than at other temperatures. At 600°C, the decrease in Tar yield of other raw materials is more obvious with increasing temperature except UF resin. The Char yield of all raw materials decreased with the increase of temperature, but the Char yield of UF resin is significantly lower than other raw materials. The fast pyrolysis of wood and particle board yields of Tar and Char are basically the same, indicating that the addition of UF resin has little effect on the fast pyrolysis products Tar and Char.

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

DOI: http://dx.doi.org/10.5772/intechopen.81522

3.1.2 Effect of carrier gas flow on yields of fast pyrolysis products

Tar and char yields from fast pyrolysis of different raw materials at different temperatures.

Figure 5.

41

Figure 6 shows the yields of fast pyrolysis products of raw materials at different carrier gas flows. As can be seen from the figure, the increase in carrier gas flow rate can effectively prevent secondary cracking in the system, therefore, the yields of fast pyrolysis oil has been greatly improved with the increase of gas flow rate, and the production of pyrolytic carbon and gaseous has gradually decreased. When the flow rate of the carrier gas continues to increase, the secondary reaction has been at a relatively low level, and therefore, the effect on the product is relatively small. Compared with temperature, the influence of carrier gas flow rate on the distribution of fast pyrolysis products is relatively low, therefore, as long as gas phase residence time of less than 3 s can be ensured, a higher pyrolysis oil yield can be

Figures 3 and 4 show the cumulative histogram of the yield distribution from fast pyrolysis products of PBL and PBP and their components at different temperatures. From Figure 3, it can be seen that due to the effect of UF resin, the yield of fast

Figure 3. Distribution of products from fast pyrolysis of PBL at different temperatures.

Figure 4. Distribution of products from fast pyrolysis of PBP at different temperatures.

#### Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

pyrolysis carbon of PBL is higher than that of Larch, and it can be inferred that UF resin will prevent the pyrolysis of the particle board at high temperatures. As the temperature rises, this inhibition slows down, at 450°C, particle board fast pyrolysis carbon is 3% higher than Larch, while the pyrolytic carbon from particle board is only 1% higher than that from Larch when the temperature reaches 600°C. The yield of pyrolysis oil from fast pyrolysis of particle board is basically the same as the yield from Larch at 450°C, and the former is less than later when the temperature setting at 500 and 550°C. However, when the temperature exceeds 600°C, the yield of pyrolysis oil from fast pyrolysis of particle board is less than that from Larch. This is because the yield of pyrolysis oil of UF resin is high than that of wood, which resulted in the superposition effect; and on the other hand, it also shows that the introduction of UF resin has an impact on the yield of pyrolysis oil, which is more sensitive to temperature. From Figure 4, it can be seen that the effect of UF resin on the yield of fast pyrolysis products of PBP is similar to that of PBL, which has an inhibitory effect on the pyrolysis process of the particle board, and increases the yield of pyrolytic carbon of the particle board, along with the temperature increased this inhibition slows down.

Figure 5 shows the content comparison diagram of Tar and Char in the fast pyrolysis products from different materials. As can be seen from the figure, the Tar yield of the UF resin is significantly higher than that of other raw materials, and the Tar yield is higher at 550°C than at other temperatures. At 600°C, the decrease in Tar yield of other raw materials is more obvious with increasing temperature except UF resin. The Char yield of all raw materials decreased with the increase of temperature, but the Char yield of UF resin is significantly lower than other raw materials. The fast pyrolysis of wood and particle board yields of Tar and Char are basically the same, indicating that the addition of UF resin has little effect on the fast pyrolysis products Tar and Char.

#### 3.1.2 Effect of carrier gas flow on yields of fast pyrolysis products

Figure 6 shows the yields of fast pyrolysis products of raw materials at different carrier gas flows. As can be seen from the figure, the increase in carrier gas flow rate can effectively prevent secondary cracking in the system, therefore, the yields of fast pyrolysis oil has been greatly improved with the increase of gas flow rate, and the production of pyrolytic carbon and gaseous has gradually decreased. When the flow rate of the carrier gas continues to increase, the secondary reaction has been at a relatively low level, and therefore, the effect on the product is relatively small. Compared with temperature, the influence of carrier gas flow rate on the distribution of fast pyrolysis products is relatively low, therefore, as long as gas phase residence time of less than 3 s can be ensured, a higher pyrolysis oil yield can be

Figure 5. Tar and char yields from fast pyrolysis of different raw materials at different temperatures.

and carboxyl groups, with the increase of temperature, these functional groups will decompose and produce gases such as CO and CO2, resulting in the increase of gas phase products, which in turn reduced the yield of pyrolysis oil. During wood pyrolysis, lignin produces more fixed carbon than cellulose and hemicellulose, so the char yield of Larch and Poplar is higher than that of UF resin. Because the structure of UF resin is not complicated with wood, the yield change of UF resin in the pyrolysis process is not as obvious as that of wood and particle board, and the products are

Figures 3 and 4 show the cumulative histogram of the yield distribution from fast pyrolysis products of PBL and PBP and their components at different temperatures. From Figure 3, it can be seen that due to the effect of UF resin, the yield of fast

relatively few, mainly ester and amine substances [16].

Figure 4.

40

Figure 3.

Analytical Pyrolysis

Distribution of products from fast pyrolysis of PBP at different temperatures.

Distribution of products from fast pyrolysis of PBL at different temperatures.

#### Figure 6.

Yields of fast pyrolysis products at different carrier gas flow rate of (a) Larch, (b) Poplar, (c) UF, (d) PBL, and (e) PBP.

the fast pyrolysis gases of various raw materials are mainly CO and CO2. With the increase of temperature, the CO content increased while the CO2 content decreased, crossover occurred within the experimental temperature range, the temperature at this intersection varies depending on the composition of the raw materials. This aspect shows that the competitive reaction of the gas generated during the fast pyrolysis process is beneficial to the production of CO2 at low temperatures, and is more conducive to the production of CO at high temperatures. It shows that the CO and CO2 generation mode and mechanism are different during the fast pyrolysis process, and the effect of temperature on them is opposite. On the other hand, the cracking of the raw material in the fast pyrolysis process is accompanied by the secondary cracking of the primary volatiles, which means that the secondary cracking of the volatiles will generate more CO at high temperature, but it will not contribute much to the generation of CO2, analysis shows that the CO is mainly produced by the cleavage of organic acids and aldehydes containing carbonyl groups and carboxyl groups. In addition, CO2 reacts with the pyrolytic carbon in the reaction system to convert to CO at higher temperatures. The experimental results are similar to the fast pyrolysis experiments performed on different biomass in the

Gaseous products distribution from fast pyrolysis at different temperature of (a) Larch, (b) Poplar, (c) UF,

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

DOI: http://dx.doi.org/10.5772/intechopen.81522

As can be seen from Figure 8, the yield of several other gases is very small, with a relatively high H2 content of about 5–10%, while the amount of CH4 and C2H4 is less than 2%. With the increase of temperature, the amount of these gases has increased to some extent, and the overall calorific value of the fast pyrolysis gas has increased. The main reasons for the increase of H2 yield are: the condensation of char; secondary reaction of tar, such as the polycondensation of aldehyde and ketone compounds; cracking of alkanes and alkenes. With the increase of temperature, the polycondensation reaction is enhanced. Some compounds in tar undergo polycondensation reaction to form benzene ring and other structures, and form H, which eventually leads to the increase of H2 content. For hydrocarbons, the C-H bond and the stability of C-C bond in the order: CC>C=C > C-H > C-C, however,

literature.

43

Figure 8.

(d) PBL, and (e) PBP.

#### Figure 7.

Tar and char yields from fast pyrolysis of different raw materials at different flow rates.

obtained. Of course, increasing the flow rate of the carrier gas will contributes to the increase of pyrolysis oil yield, where other conditions permit.

Figure 7 shows the comparison of Tar and Char contents in fast pyrolysis products of different raw materials. From the figure, we can see that the Tar yield of UF resin increases with the increase of the carrier gas flow rate, which is basically the same as other raw materials, indicating that the degree of secondary pyrolysis of UF resin is equivalent to that of other raw materials. It shows that under the condition of fast pyrolysis, the addition of UF resin has no obvious effect on the wood and particle board product.

#### 3.2 Influence of pyrolysis conditions on composition of fast pyrolysis products of waste particle board

#### 3.2.1 Influence of pyrolysis conditions on distribution of gas product composition

Figure 8 changes of the gas composition in fast pyrolysis of raw materials at different temperatures. As can be seen from the figure, at different temperatures, Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

#### Figure 8.

Gaseous products distribution from fast pyrolysis at different temperature of (a) Larch, (b) Poplar, (c) UF, (d) PBL, and (e) PBP.

the fast pyrolysis gases of various raw materials are mainly CO and CO2. With the increase of temperature, the CO content increased while the CO2 content decreased, crossover occurred within the experimental temperature range, the temperature at this intersection varies depending on the composition of the raw materials. This aspect shows that the competitive reaction of the gas generated during the fast pyrolysis process is beneficial to the production of CO2 at low temperatures, and is more conducive to the production of CO at high temperatures. It shows that the CO and CO2 generation mode and mechanism are different during the fast pyrolysis process, and the effect of temperature on them is opposite. On the other hand, the cracking of the raw material in the fast pyrolysis process is accompanied by the secondary cracking of the primary volatiles, which means that the secondary cracking of the volatiles will generate more CO at high temperature, but it will not contribute much to the generation of CO2, analysis shows that the CO is mainly produced by the cleavage of organic acids and aldehydes containing carbonyl groups and carboxyl groups. In addition, CO2 reacts with the pyrolytic carbon in the reaction system to convert to CO at higher temperatures. The experimental results are similar to the fast pyrolysis experiments performed on different biomass in the literature.

As can be seen from Figure 8, the yield of several other gases is very small, with a relatively high H2 content of about 5–10%, while the amount of CH4 and C2H4 is less than 2%. With the increase of temperature, the amount of these gases has increased to some extent, and the overall calorific value of the fast pyrolysis gas has increased. The main reasons for the increase of H2 yield are: the condensation of char; secondary reaction of tar, such as the polycondensation of aldehyde and ketone compounds; cracking of alkanes and alkenes. With the increase of temperature, the polycondensation reaction is enhanced. Some compounds in tar undergo polycondensation reaction to form benzene ring and other structures, and form H, which eventually leads to the increase of H2 content. For hydrocarbons, the C-H bond and the stability of C-C bond in the order: CC>C=C > C-H > C-C, however,

obtained. Of course, increasing the flow rate of the carrier gas will contributes to the

Yields of fast pyrolysis products at different carrier gas flow rate of (a) Larch, (b) Poplar, (c) UF, (d) PBL,

Figure 7 shows the comparison of Tar and Char contents in fast pyrolysis products of different raw materials. From the figure, we can see that the Tar yield of UF resin increases with the increase of the carrier gas flow rate, which is basically the same as other raw materials, indicating that the degree of secondary pyrolysis of UF resin is equivalent to that of other raw materials. It shows that under the condition of fast pyrolysis, the addition of UF resin has no obvious effect on the

increase of pyrolysis oil yield, where other conditions permit.

Tar and char yields from fast pyrolysis of different raw materials at different flow rates.

3.2 Influence of pyrolysis conditions on composition of fast

3.2.1 Influence of pyrolysis conditions on distribution of gas product composition

Figure 8 changes of the gas composition in fast pyrolysis of raw materials at different temperatures. As can be seen from the figure, at different temperatures,

pyrolysis products of waste particle board

wood and particle board product.

Figure 6.

Figure 7.

42

and (e) PBP.

Analytical Pyrolysis

at high temperatures alkane content in tar is less, and alkenes, alkynes and aromatic compounds content is higher, compared with the C-H, C-C bond in tar is less, resulting in high temperature tar cracking process of CH4 is less than the H2. The variation pattern of CH4 and C2H4 is similar to that of CO. In the study of biomass thermal cracking, the generation of CH4 is mostly derived from the methoxy group in lignin structure, and the secondary decomposition of the volatile component of cellulose polymer can also produce CH4. The detected unsaturated hydrocarbons are mainly C2H4, the yield of C2H4 is similar to that of CH4, and the content in the gas is also very low. The analysis of its formation may be obtained from the thermal decomposition of unsaturated fatty acids.

Figure 9 shows the comparison of CO and CO2 contents in fast pyrolysis gases of different raw materials. From the figure, we can see that the CO yield of UF with temperature rise is more obvious than that of wood and particle board, but the trend of CO2 falling with temperature is basically the same. It shows that the UF contains a large amount of carbonyl groups which will be pyrolyzed to generate more CO during the fast pyrolysis process. Compared with two types of wood, the amount of CO and CO2 produced from Larch is higher than that produced from Poplar, this is caused by the difference in the composition of the two types of wood. The yields of CO and CO2 produced by pyrolysis of wood and particle board are basically the same, indicating that the addition of UF resin has no obvious effect on the fast pyrolysis of gas products.

Figure 10 is the variation diagram of the components of gaseous products from fast pyrolysis at different carrier gas flow rates. From this figure, it can be seen that under different carrier gas flow rates, CO and CO2 are predominant in the fast pyrolysis gas composition of various raw materials. With the increase of flow rate, the content of CO and other gases have decreased to varying degrees, while the CO2 content has increased. An increase in the flow rate of the carrier gas leads to a reduction in the retention time of the gas phase, thereby reducing the secondary cracking of the primary volatiles, so that the overall production of the gas product will decrease. The decrease of CO content and the increase of CO2 content indicate that the secondary cracking of volatiles is more likely to produce CO, but has little effect on CO2. Therefore, the percentage of CO2 will increase as the total amount of gas decreases.

Figure 11 shows the comparison of CO and CO2 contents in fast pyrolysis gases of different raw materials. From the figure, we can see that the CO yield of UF resin decreases with the increase of the carrier gas flow rate, which is basically the same as other raw materials, indicating that the degree of secondary pyrolysis of UF resin is equivalent to that of other raw materials. It shows that under the condition of fast pyrolysis, the addition of UF resin has no obvious effect on the wood gas product.

3.2.2 Influence of pyrolysis conditions on the distribution of liquid product components

Gaseous products distribution from fast pyrolysis at different carrier gas flow rates of raw materials: (a) Larch,

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

CO and CO2 contents fast pyrolysis products at different carrier gas flow rates.

particle board are the same as the Larch.

Figure 11.

45

Figure 10.

(b) Poplar, (c) UF, (d) PBL, and (e) PBP.

DOI: http://dx.doi.org/10.5772/intechopen.81522

Figure 12 is a GC/MS total ion chromatogram (TIC) of the liquid product from fast pyrolysis of Larch, UF, and PBL, at 500°C. Due to the relatively simple structure of the UF resin, the TIC peak of the products from fast pyrolysis of UF resin is significantly lower than the TIC peak of the products from pyrolysis of wood and particle board, and no product peak appears after more than 30 minutes of retention time. When using the NIST library search, about 90 substances can be detected for the pyrolysis liquid phase products of particle board and wood raw materials under different conditions. The UF resin produced the most substances when it was pyrolyzed at 500°C, and only 37 products were found. The main components and relative content of liquid phase products of Larch, UF resin and PBL are shown in the appendix table. The spectral peaks of the PBL are very similar to those of the Larch, indicating that the main components of the pyrolysis products of the waste

Figure 9. CO and CO2 yields from fast pyrolysis of different raw materials at different temperatures.

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

Figure 10.

at high temperatures alkane content in tar is less, and alkenes, alkynes and aromatic compounds content is higher, compared with the C-H, C-C bond in tar is less, resulting in high temperature tar cracking process of CH4 is less than the H2. The variation pattern of CH4 and C2H4 is similar to that of CO. In the study of biomass thermal cracking, the generation of CH4 is mostly derived from the methoxy group in lignin structure, and the secondary decomposition of the volatile component of cellulose polymer can also produce CH4. The detected unsaturated hydrocarbons are mainly C2H4, the yield of C2H4 is similar to that of CH4, and the content in the gas is also very low. The analysis of its formation may be obtained from the thermal

Figure 9 shows the comparison of CO and CO2 contents in fast pyrolysis gases of different raw materials. From the figure, we can see that the CO yield of UF with temperature rise is more obvious than that of wood and particle board, but the trend of CO2 falling with temperature is basically the same. It shows that the UF contains a large amount of carbonyl groups which will be pyrolyzed to generate more CO during the fast pyrolysis process. Compared with two types of wood, the amount of CO and CO2 produced from Larch is higher than that produced from Poplar, this is caused by the difference in the composition of the two types of wood. The yields of CO and CO2 produced by pyrolysis of wood and particle board are basically the same, indicating that the addition of UF resin has no obvious effect on

Figure 10 is the variation diagram of the components of gaseous products from fast pyrolysis at different carrier gas flow rates. From this figure, it can be seen that under different carrier gas flow rates, CO and CO2 are predominant in the fast pyrolysis gas composition of various raw materials. With the increase of flow rate, the content of CO and other gases have decreased to varying degrees, while the CO2 content has increased. An increase in the flow rate of the carrier gas leads to a reduction in the retention time of the gas phase, thereby reducing the secondary cracking of the primary volatiles, so that the overall production of the gas product will decrease. The decrease of CO content and the increase of CO2 content indicate that the secondary cracking of volatiles is more likely to produce CO, but has little effect on CO2. Therefore, the percentage of CO2 will increase as the total amount of

Figure 11 shows the comparison of CO and CO2 contents in fast pyrolysis gases of different raw materials. From the figure, we can see that the CO yield of UF resin decreases with the increase of the carrier gas flow rate, which is basically the same as other raw materials, indicating that the degree of secondary pyrolysis of UF resin is equivalent to that of other raw materials. It shows that under the condition of fast pyrolysis, the addition of UF resin has no obvious effect on the wood gas product.

CO and CO2 yields from fast pyrolysis of different raw materials at different temperatures.

decomposition of unsaturated fatty acids.

Analytical Pyrolysis

the fast pyrolysis of gas products.

gas decreases.

Figure 9.

44

Gaseous products distribution from fast pyrolysis at different carrier gas flow rates of raw materials: (a) Larch, (b) Poplar, (c) UF, (d) PBL, and (e) PBP.

Figure 11.

CO and CO2 contents fast pyrolysis products at different carrier gas flow rates.

#### 3.2.2 Influence of pyrolysis conditions on the distribution of liquid product components

Figure 12 is a GC/MS total ion chromatogram (TIC) of the liquid product from fast pyrolysis of Larch, UF, and PBL, at 500°C. Due to the relatively simple structure of the UF resin, the TIC peak of the products from fast pyrolysis of UF resin is significantly lower than the TIC peak of the products from pyrolysis of wood and particle board, and no product peak appears after more than 30 minutes of retention time. When using the NIST library search, about 90 substances can be detected for the pyrolysis liquid phase products of particle board and wood raw materials under different conditions. The UF resin produced the most substances when it was pyrolyzed at 500°C, and only 37 products were found. The main components and relative content of liquid phase products of Larch, UF resin and PBL are shown in the appendix table. The spectral peaks of the PBL are very similar to those of the Larch, indicating that the main components of the pyrolysis products of the waste particle board are the same as the Larch.

Figure 12. TIC spectra of liquid products from fast pyrolysis of Larch, UF and PBL.

By classifying and comparing the pyrolysis liquid product components, the effect of pyrolysis conditions on the main categories of fast pyrolysis products can be analyzed. The products detected by GC/MS are classified into 13 categories, which are amines, alcohols, phenols, aldehydes, acids, ketones, esters, ethers, sugars, hydrocarbons, heterocyclic-N, other-N and others. From the appendix table, it can be seen that nitrogenous substances are the main components of UF resin pyrolysis liquid. UF resin contains amino, carbonyl, methylene and other groups, during the pyrolysis of UF resin, a group of hydroxyl methyl groups first split into formaldehyde and then produce nitrogen-containing volatile components with C-N bond breaking. The relative content of methyl isocyanate reaches up to 39.25%, in addition, other nitrogenous substances, such as ethyleneimine (13.68%), ethyl pyruvate (10.67%), 2,3-diazabicyclo [2.2.1]-hept-2-ene decanols (5.13%), l-alanine ethylamide, (S)-(3.91%), can also be detected in the pyrolysis liquid of UF resin. Compared with the composition of UF resin, the pyrolytic liquid products of Larch and PBL are very complicated. The products of wood mainly include alcohols, ketones, aldehydes, ketone derivatives and carbohydrates. The major constituent is hydroxyacetone and the relative content is 7.43%, other ketone derivatives, such as 1,3-cyclopentadione (3.12%) and 2,3-glutaric ketone (2.53%) can also be detected in the pyrolysis liquid of Larch, these ketone derivatives are generated by the pyrolysis of holocellulose. Lignin structure is rich in methoxy, and most phenolic compounds in the pyrolysis solution have the methoxyl chain. During the pyrolysis, the lignin molecular chain is cracked and the fragments are rearranged. The relative content of cis-isoeugenol and 2-methoxyl-4-vinyl phenol in Larch liquid phase products can reach 4.96 and 3.08%, respectively. In addition, phenolic compounds such as 4-ethyl guaiacol (1.38%), guaiacol (2.76%), 4-methyl guaiacol (2.53%), eugenol (1.32%) and phenol (0.33%) can also be detected. Particle board pyrolysis liquid product variety is one of the most in the three kinds of raw materials, main components of acetic acid (13.04%), (E)-iso-eugenol (5.22%), guaiacol (5.07%), cyclopropylmethyl alcohol (4.81%), 4-methyl hydroxyacetone (4.24%), guaiacol (3.97%), 4-hydroxy-3-methyl acetophenone (3.48%), 3-methyl-1, 2-ring glutaric ketone (2.98%) and furfuryl alcohol (2.75%), and other substances phenols, alcohols and ketones. Compared with Larch pyrolysis liquid phase, more Larch and

UF resin synergistic reaction products, such as 1,3,4-trimethyl-1,7-dihydro-6hpyrazole and [3,4-b] pyridine 6-ketone, were obtained in the pyrolysis liquid phase

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

Subtotal amount of different categories of fast pyrolysis liquid products (T = 500°C).

Larch, UF and PBL at 500°C. As can be seen from the figure, the type of fast pyrolysis liquid product of PBL is the same as that of Larch, and is mainly based on alcohol, phenol, acid, and ketone, the maximum content of esters in the urea-formaldehyde resin pyrolysis liquid phase product is nearly 50%, which together with amines, nitrogen heterocycles and other nitrogen-containing compounds form the main liquid phase products. Due to the effect of UF resin, the product of PBL has a greater change than Larch, and the nitrogen heterocyclic compound in the PBL has been greatly improved compared to wood. In addition, acid and phenolic substances have also been improved to varying degrees, while amines, alcohols, aldehydes, esters, sugars and other components have been reduced to varying degrees. The change of these components is due to the fact that the introduced UF resin itself is produced during the fast pyrolysis process, for example, the nitrogen heterocyclic compounds are mainly formed by the cyclization of the amide nitrogen from fast pyrolysis of UF resin. However, more compositional changes should result from the complex chemical reactions that occurred between the UF resin and wood components during the fast pyrolysis process, for example, amines and esters are the main products of UF resin, but the content of PBL products is lower than that of wood products. Phenolics and acids were not detected in the UF resin pyrolysis liquid phase product, but the content of PBL products was higher than that of wood. Therefore, during the fast pyrolysis of the particle board, a strong interaction occurs between the wood components and the UF resin component, in other words, chemical reactions occurred between the

derivatives from UF resin and wood during fast pyrolysis.

Figure 13 is a summary of the main components of the fast pyrolysis liquid of

products of particle board [16].

DOI: http://dx.doi.org/10.5772/intechopen.81522

Figure 13.

47

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

Figure 13. Subtotal amount of different categories of fast pyrolysis liquid products (T = 500°C).

UF resin synergistic reaction products, such as 1,3,4-trimethyl-1,7-dihydro-6hpyrazole and [3,4-b] pyridine 6-ketone, were obtained in the pyrolysis liquid phase products of particle board [16].

Figure 13 is a summary of the main components of the fast pyrolysis liquid of Larch, UF and PBL at 500°C. As can be seen from the figure, the type of fast pyrolysis liquid product of PBL is the same as that of Larch, and is mainly based on alcohol, phenol, acid, and ketone, the maximum content of esters in the urea-formaldehyde resin pyrolysis liquid phase product is nearly 50%, which together with amines, nitrogen heterocycles and other nitrogen-containing compounds form the main liquid phase products. Due to the effect of UF resin, the product of PBL has a greater change than Larch, and the nitrogen heterocyclic compound in the PBL has been greatly improved compared to wood. In addition, acid and phenolic substances have also been improved to varying degrees, while amines, alcohols, aldehydes, esters, sugars and other components have been reduced to varying degrees. The change of these components is due to the fact that the introduced UF resin itself is produced during the fast pyrolysis process, for example, the nitrogen heterocyclic compounds are mainly formed by the cyclization of the amide nitrogen from fast pyrolysis of UF resin. However, more compositional changes should result from the complex chemical reactions that occurred between the UF resin and wood components during the fast pyrolysis process, for example, amines and esters are the main products of UF resin, but the content of PBL products is lower than that of wood products. Phenolics and acids were not detected in the UF resin pyrolysis liquid phase product, but the content of PBL products was higher than that of wood. Therefore, during the fast pyrolysis of the particle board, a strong interaction occurs between the wood components and the UF resin component, in other words, chemical reactions occurred between the derivatives from UF resin and wood during fast pyrolysis.

By classifying and comparing the pyrolysis liquid product components, the effect of pyrolysis conditions on the main categories of fast pyrolysis products can be analyzed. The products detected by GC/MS are classified into 13 categories, which are amines, alcohols, phenols, aldehydes, acids, ketones, esters, ethers, sugars, hydrocarbons, heterocyclic-N, other-N and others. From the appendix table, it can be seen that nitrogenous substances are the main components of UF resin pyrolysis liquid. UF resin contains amino, carbonyl, methylene and other groups, during the pyrolysis of UF resin, a group of hydroxyl methyl groups first split into formaldehyde and then produce nitrogen-containing volatile components with C-N bond breaking. The relative content of methyl isocyanate reaches up to 39.25%, in addition, other nitrogenous substances, such as ethyleneimine (13.68%), ethyl pyruvate (10.67%), 2,3-diazabicyclo [2.2.1]-hept-2-ene decanols (5.13%), l-alanine ethylamide, (S)-(3.91%), can also be detected in the pyrolysis liquid of UF resin. Compared with the composition of UF resin, the pyrolytic liquid products of Larch and PBL are very complicated. The products of wood mainly include alcohols, ketones, aldehydes, ketone derivatives and carbohydrates. The major constituent is hydroxyacetone and the relative content is 7.43%, other ketone derivatives, such as 1,3-cyclopentadione (3.12%) and 2,3-glutaric ketone (2.53%) can also be detected in the pyrolysis liquid of Larch, these ketone derivatives are generated by the pyrolysis of holocellulose. Lignin structure is rich in methoxy, and most phenolic compounds in the pyrolysis solution have the methoxyl chain. During the pyrolysis, the lignin molecular chain is cracked and the fragments are rearranged. The relative content of cis-isoeugenol and 2-methoxyl-4-vinyl phenol in Larch liquid phase products can reach 4.96 and 3.08%, respectively. In addition, phenolic compounds such as 4-ethyl guaiacol (1.38%), guaiacol (2.76%), 4-methyl guaiacol (2.53%), eugenol (1.32%) and phenol (0.33%) can also be detected. Particle board pyrolysis liquid product variety is one of the most in the three kinds of raw materials, main components of acetic acid (13.04%), (E)-iso-eugenol (5.22%), guaiacol (5.07%), cyclopropylmethyl alcohol (4.81%), 4-methyl hydroxyacetone (4.24%), guaiacol (3.97%), 4-hydroxy-3-methyl acetophenone (3.48%), 3-methyl-1, 2-ring glutaric ketone (2.98%) and furfuryl alcohol (2.75%), and other substances phenols, alcohols and ketones. Compared with Larch pyrolysis liquid phase, more Larch and

TIC spectra of liquid products from fast pyrolysis of Larch, UF and PBL.

Figure 12.

Analytical Pyrolysis

46

10 ml/min. It can be seen from the figure that with the decrease of the carrier gas flow rates, the gas phase residence time is prolonged and the secondary cracking of the volatiles is enhanced, more small molecules are produced. From the liquid product search results, it was found that the product types did not change, the content of the higher molecular weight material decreased, and the content of the

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

DOI: http://dx.doi.org/10.5772/intechopen.81522

Subtotal amounts of different categories of PBL fast pyrolysis liquid products at different carry gas flow rates.

Subtotal amounts of different categories liquid products from fast pyrolysis of PBL with different adhesive

Figure 15.

Figure 16.

amounts.

49

Figure 14. Subtotal amounts of different categories of liquid products from fast pyrolysis of PBL at different temperatures.

Temperature is one of the main factors affecting fast pyrolysis. Figure 14 is a summary of the main components of liquid products from fast pyrolysis of PBL at different temperatures. From the figure, it can be seen that the content of liquid products from fast pyrolysis of the PBL at 500°C is generally higher than that at 400 and 600°C, such as alcohol, phenol, acid, ketone, etc., this is consistent with the trend of maximum yield of pyrolysis oil obtained at a fixed bed fast pyrolysis experiment at 500°C. When the temperature is lower, the cracking of raw materials is incomplete and the yield of volatiles is low, when the temperature is higher, more secondary cracking occurs in the volatiles and they are converted into small molecules. The effect of temperature on the specific components of the product and its mechanism remain to be further studied.

It can also be seen from Figure 14 that the nitrogen-containing compounds account for the most part in liquid phase products from fast pyrolysis of particle board at a lower temperature of 400°C, mainly amines, nitrogen heterocyclic, etc., indicating that at low temperatures UF resin already be decomposed to produce liquid products. When the temperature rises to 500°C, the amines, nitrogen heterocycles and other liquid nitrogen compounds in the product have been significantly reduced, indicating that some low-stability substances undergo secondary cracking to generate small-molecule gas-phase compounds, while the secondary cleavage of nitrogen heterocycles with higher stability is still not obvious. When the temperature continues to increase to 600°C, the nitrogen heterocyclic ring in the product is significantly reduced, indicating that at higher temperatures, a large number of nitrogen heterocycles also undergo cracking reactions. As a result, amines, nitrogen-containing esters, and other nitrogen-containing compounds are produced, making the amount of these substances significantly higher than at 500°C. These changes are similar to the effects of temperature on pyrolysis yields. Therefore, in the fast pyrolysis process, the temperature has a decisive effect on the product yield and composition.

Figure 15 is a summary of the main components of the liquid phase product of the PBL at different carrier gas flow rates. The flow rates were set to 100, 50 and

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

10 ml/min. It can be seen from the figure that with the decrease of the carrier gas flow rates, the gas phase residence time is prolonged and the secondary cracking of the volatiles is enhanced, more small molecules are produced. From the liquid product search results, it was found that the product types did not change, the content of the higher molecular weight material decreased, and the content of the

Figure 15. Subtotal amounts of different categories of PBL fast pyrolysis liquid products at different carry gas flow rates.

Figure 16. Subtotal amounts of different categories liquid products from fast pyrolysis of PBL with different adhesive amounts.

49

Temperature is one of the main factors affecting fast pyrolysis. Figure 14 is a summary of the main components of liquid products from fast pyrolysis of PBL at different temperatures. From the figure, it can be seen that the content of liquid products from fast pyrolysis of the PBL at 500°C is generally higher than that at 400 and 600°C, such as alcohol, phenol, acid, ketone, etc., this is consistent with the trend of maximum yield of pyrolysis oil obtained at a fixed bed fast pyrolysis experiment at 500°C. When the temperature is lower, the cracking of raw materials is incomplete and the yield of volatiles is low, when the temperature is higher, more secondary cracking occurs in the volatiles and they are converted into small molecules. The effect of temperature on the specific components of the product and its

Subtotal amounts of different categories of liquid products from fast pyrolysis of PBL at different temperatures.

It can also be seen from Figure 14 that the nitrogen-containing compounds account for the most part in liquid phase products from fast pyrolysis of particle board at a lower temperature of 400°C, mainly amines, nitrogen heterocyclic, etc., indicating that at low temperatures UF resin already be decomposed to produce liquid products. When the temperature rises to 500°C, the amines, nitrogen heterocycles and other liquid nitrogen compounds in the product have been significantly reduced, indicating that some low-stability substances undergo secondary cracking to generate small-molecule gas-phase compounds, while the secondary cleavage of nitrogen heterocycles with higher stability is still not obvious. When the temperature continues to increase to 600°C, the nitrogen heterocyclic ring in the product is significantly reduced, indicating that at higher temperatures, a large number of nitrogen heterocycles also undergo cracking reactions. As a result, amines, nitrogen-containing esters, and other nitrogen-containing compounds are produced, making the amount of these substances significantly higher than at 500°C. These changes are similar to the effects of temperature on pyrolysis yields. Therefore, in the fast pyrolysis process, the temperature has a decisive effect on the

Figure 15 is a summary of the main components of the liquid phase product of the PBL at different carrier gas flow rates. The flow rates were set to 100, 50 and

mechanism remain to be further studied.

Figure 14.

Analytical Pyrolysis

product yield and composition.

48

lower molecular weight material increased. Under different temperature conditions, the yield of the same product is not much different, which indicates that the carrier gas flow rates has little influence on the product quantity, and the overall influence degree is not as obvious as the temperature.

Acknowledgements

DOI: http://dx.doi.org/10.5772/intechopen.81522

Universities (2017ZY32).

UF and PBL

51

The work was supported by the Fundamental Research Funds for the Central

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

1 Ethyleneimine C2H5N 43 \ \ 13.68 2 Formamide CH3NO 45 0.27 1.61 0.11 3 Aminoacetonitrile C2H4N2 56 \ \ 0.03 4 Methyl isocyanate C2H3NO 57 \ 1.23 39.25 5 Acetamide C2H5NO 59 6.53 0.57 \ 6 N-Methylformamide C2H5NO 59 \ 0.64 \ 7 Trimethylamine C3H9N 59 \ \ 2.56 8 Acetic acid C2H4O2 60 2.25 13.04 \ 9 Ethylene glycol C2H6O2 62 \ 0.68 \ 10 Pyrrole C4H5N 67 0.42 1.83 \ 11 Allyl cyanide C4H5N 67 \ \ 0.05 12 2,5-Dihydrofuran C4H6O 70 0.3 0.13 \ 13 Cyclopropylmethanol C4H8O 72 3.34 4.81 \ 14 N-Methylacetamide C3H7NO 73 \ 0.52 \ 15 Hydroxyacetone C3H6O2 74 7.43 4.24 \ 16 Methyl acetate C3H6O2 74 \ 1.41 \ 17 Methylurea C2H6N2O 74 \ \ 0.09 18 Methyl carbamate C2H5NO2 75 \ \ 0.14 19 Pyridine C5H5N 79 0.14 \ \ 20 Pyrimidine C4H4N2 80 \ 0.47 \ 21 N-methylpyrrole C5H7N 81 0.32 1.39 \ 22 3-Methylpyrrole C5H7N 81 \ 0.33 \ 23 1,3,5-Triazine C3H3N3 81 \ \ 1.21 24 1,4-Pentadien-3-one C5H6O 82 0.39 \ \ 25 N-methylimidazole C4H6N2 82 \ 0.56 0.06 26 2(5H)-Furanone C4H4O2 84 1.92 2.19 \ 27 N,N-Dimethylaminoacetonitrile C4H8N2 84 \ 1.12 0.66 28 Succinaldehyde C4H6O2 86 2.01 \ \ 29 2,3-Butanedione C4H6O2 86 \ 1.05 \ 30 Beta-butyrolactone C4H6O2 86 \ \ 0.21 31 1-Hydroxy-2-butanone C4H8O2 88 \ 0.98 \ 32 N,N-Dimethylurea C3H8N2O 88 \ \ 0.56

formula

Molecular weight

Larch Area % PBL UF

A. Main compounds of fast pyrolysis liquid products of Larch,

No. Name Molecular

Figure 16 is a summary of the main components of the liquid phase products from fast pyrolysis of PBL with different adhesive amount.

As can be seen from Figure 16, the increase in adhesive amount directly results in an increase in all nitrogenous products in the product, including amines, nitrogen heterocycles, and other nitrogen-containing compounds. In addition, the amount of ester products has also been significantly increased, the reason is that many esters contain nitrogen, which means that the amide nitrogen in the raw material is involved in a large number of esterification reactions. When the amount of adhesive is at a little level, UF resin has a promoting effect on the formation of phenol in wood, and plays a similar catalyst effect; when the amount of adhesive increases, the phenolics in the particle board begin to drop; when the amount of adhesive is 20%, it even drops to 4%, which is less than a quarter of the phenol content (20.5%) in fast pyrolysis products of wood. It is speculated that in a fast pyrolysis system, too much UF resin will compete with the phenol-forming reaction, generating more amine and nitrogen heterocyclic structures. In comparison, the effects of UF resin on acid substances are similar to those on phenolic substances, less adhesive amounts contribute to the formation of acids, while an increase in the amount of sizing inhibits acid production and appears to decrease.

#### 4. Conclusions

Fast pyrolysis experiments of Larch and Poplar, UF, PBL and PBP were carried out, and the yields of pyrolysis products and its composition were analyzed. The results show that when the pyrolysis temperature is between 400 and 600°C, the gas yield steadily increase as the temperature increases, and the pyrolysis carbon yield continues to decrease, while the yield of pyrolysis oil increased at first and then decreased afterwards, and reached a maximum at 550°C. The carbon yield from fast pyrolysis of particle board is higher than that of wood, indicating that UF resin will prevent particle board decomposing, and this impact goes weak with increasing of temperature.

Compared with temperature, the influence of the carrier gas flow rates on the yields of products and its distribution is relatively low. Increasing of carrier gas flow rate can effectively prevent the occurrence of secondary cracking in the system and increase the pyrolysis oil yield. The gas products from fast pyrolysis of waste particle board are mainly CO and CO2, as well as relatively small amounts of CH4, C2H4, H2, etc. With the increase of temperature, the content of CO2 decreased and the contents of other gases increased. Among them, the tendency of CO obviously rose, and the calorific value of gas has increased. Under the conditions of fast pyrolysis, the effect of UF resin on the gas composition of particle board is not obvious.

Compared with wood, the main components of pyrolysis liquid phase products of waste particle board have not changed much, while the nitrogenous substances such as amines and nitrogen heterocycles are mainly increased, which promoted the formation of phenols and acids and prevented the formation of aldehydes, sugars, and alcohols. The temperature has little effect on the product type, but has a great influence on the yields. The carrier gas flow rate has little effect on the product composition. The effect of adhesive amount on the composition of the product is unclear.

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

#### Acknowledgements

lower molecular weight material increased. Under different temperature conditions, the yield of the same product is not much different, which indicates that the carrier gas flow rates has little influence on the product quantity, and the overall

Figure 16 is a summary of the main components of the liquid phase products

As can be seen from Figure 16, the increase in adhesive amount directly results in an increase in all nitrogenous products in the product, including amines, nitrogen heterocycles, and other nitrogen-containing compounds. In addition, the amount of ester products has also been significantly increased, the reason is that many esters contain nitrogen, which means that the amide nitrogen in the raw material is involved in a large number of esterification reactions. When the amount of adhesive is at a little level, UF resin has a promoting effect on the formation of phenol in wood, and plays a similar catalyst effect; when the amount of adhesive increases, the phenolics in the particle board begin to drop; when the amount of adhesive is 20%, it even drops to 4%, which is less than a quarter of the phenol content (20.5%) in fast pyrolysis products of wood. It is speculated that in a fast pyrolysis system, too much UF resin will compete with the phenol-forming reaction, generating more amine and nitrogen heterocyclic structures. In comparison, the effects of UF resin on acid substances are similar to those on phenolic substances, less adhesive amounts contribute to the formation of acids, while an increase in the amount of

Fast pyrolysis experiments of Larch and Poplar, UF, PBL and PBP were carried out, and the yields of pyrolysis products and its composition were analyzed. The results show that when the pyrolysis temperature is between 400 and 600°C, the gas yield steadily increase as the temperature increases, and the pyrolysis carbon yield continues to decrease, while the yield of pyrolysis oil increased at first and then decreased afterwards, and reached a maximum at 550°C. The carbon yield from fast pyrolysis of particle board is higher than that of wood, indicating that UF resin will prevent particle board decomposing, and this impact goes weak with

Compared with temperature, the influence of the carrier gas flow rates on the yields of products and its distribution is relatively low. Increasing of carrier gas flow rate can effectively prevent the occurrence of secondary cracking in the system and increase the pyrolysis oil yield. The gas products from fast pyrolysis of waste particle board are mainly CO and CO2, as well as relatively small amounts of CH4, C2H4, H2, etc. With the increase of temperature, the content of CO2 decreased and the contents of other gases increased. Among them, the tendency of CO obviously rose, and the calorific value of gas has increased. Under the conditions of fast pyrolysis, the effect of UF resin on the gas composition of particle board is not

Compared with wood, the main components of pyrolysis liquid phase products of waste particle board have not changed much, while the nitrogenous substances such as amines and nitrogen heterocycles are mainly increased, which promoted the formation of phenols and acids and prevented the formation of aldehydes, sugars, and alcohols. The temperature has little effect on the product type, but has a great influence on the yields. The carrier gas flow rate has little effect on the product composition. The effect of adhesive amount on the composition of the product is

influence degree is not as obvious as the temperature.

from fast pyrolysis of PBL with different adhesive amount.

sizing inhibits acid production and appears to decrease.

4. Conclusions

Analytical Pyrolysis

increasing of temperature.

obvious.

unclear.

50

The work was supported by the Fundamental Research Funds for the Central Universities (2017ZY32).

#### A. Main compounds of fast pyrolysis liquid products of Larch, UF and PBL



No. Name Molecular

DOI: http://dx.doi.org/10.5772/intechopen.81522

98 2-(1,1-Dimethylethyl)-1,3-dimethylnitrogen

propidine

53

formula

73 3-Methyl-1,2-cyclopentanedione C6H8O2 112 1.72 2.98 \ 74 3-Methyl-1,2-cyclopentanedione C6H8O2 112 1.2 \ \ 75 Cyclopentyl ethanone C7H12O 112 \ 0.14 \ 76 3-Isopropoxypropionitrile C6H11NO 113 \ 0.11 \ 77 2,3-Dimethylene-1,4-butanediol C6H10O2 114 \ 0.51 \ 78 Trans-2-hexenoic acid C6H10O2 114 0.28 \ \ 79 2,5-Dione piperazine C4H6N2O2 114 \ \ 0.25 80 5,6-Dihydrouracil C4H6N2O2 114 \ \ 0.09 81 2,6-Dimethylpiperazine C6H14N2 114 \ \ 0.56 82 l-Alanine ethylamide, (S)- C5H12N2O 116 \ \ 3.91 83 Acetylacetone peroxide C5H8O3 116 0.68 1.02 \ 84 Ethyl pyruvate C5H8O3 116 \ \ 10.67 85 1,4-Dioxane-2,5-diol C4H8O4 120 5.66 \ \ 86 1-Methyl-2-pyrrolethane cyanide C7H8N2 120 \ \ 0.11 87 (Ethyleneoxy)benzene C8H8O 120 0.34 \ \ 88 Guaiacol C7H8O2 124 2.76 5.07 \ 89 N-(S-triazolyl)acetamide C4H6N4O 126 \ 0.08 \ 90 2-Methyl-1,5-heptadiene-4-alcohol C8H14O 126 0.14 \ \ 91 Maltol C6H6O3 126 0.34 0.36 \ 92 5-Hydroxymethylfurfural C6H6O3 126 0.67 \ \ 93 Imidazol-4-acetic acid C5H6N2O2 126 \ 2.65 \ 94 3-Ethyl-4-methyl-3-pentene-2-ketone C8H14O 126 0.39 \ \ 95 2-Methyl cycloheptanone C8H14O 126 0.6 \ \ 96 Ethyl cyclopentenolone C7H10O2 126 \ 0.53 \ 97 1-Methyluracil C5H6N2O2 126 \ 0.12 \

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

99 2,3-Dimethylcyclohexanol C8H16O 128 0.26 \ \ 100 1-Cyclopropyl-1-pentyl alcohol C8H16O 128 \ 0.17 \ 101 6-Heptanoic acid C7H12O2 128 0.38 \ \ 102 3-Symplectic ketone C8H16O 128 \ 0.43 \ 103 1-Methyl-hydrouracil C5H8N2O2 128 \ 1.53 0.35 104 1,3,5-Trimethyl-hexamethyl-1,3,5-triazine C6H15N3 129 \ \ 3.16 105 L-Ornithine C5H12N2O2 132 \ \ 0.1 106 4-Methyl guaiacol C8H10O2 138 2.53 3.97 \ 107 Hexamethylenetetramine C6H12N4 140 \ \ 0.03 108 3-Oxy-1-cyclopentene-1-acetate C7H8O3 140 0.63 \ \ 109 Dipropylene aminoacetonitrile C8H16N2 140 \ \ 0.14 110 Heptyl isocyanate C8H15NO 141 0.43 \ \ 111 (1Z)-2-Ethylcyclohexanone oxime C8H15NO 141 0.28 \ \ 112 4-Octyne-3,6-diol C8H14O2 142 0.27 \ \

Molecular weight

C8H17N 127 \ \ 1.46

Larch Area % PBL


#### Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

No. Name Molecular

Analytical Pyrolysis

52

formula

33 Carbohydrazide CH6N4O 90 \ \ 0.2 34 Methyl hydroxyacetate C3H6O3 90 0.51 0.47 \ 35 Phenol C6H6O 94 0.33 \ \ 36 3-Methylpyridazine C5H6N2 94 0.17 \ \ 37 N-Vinylimidazole C5H6N2 94 \ \ 0.1 38 2,3-Dimethyl-1H-pyrrole C6H9N 95 0.25 \ \ 39 3-Hydroxypyridine C5H5NO 95 0.56 \ \ 40 2,5-Lutidine C6H9N 95 \ 0.57 \ 41 Furfural C5H4O2 96 2.21 1.34 \ 42 4-Imidazole formaldehyde C4H4N2O 96 0.16 \ \ 43 4-Cyclopentene-1,3-dione C5H4O2 96 0.29 0.22 \ 44 3-Methyl-2-cycloalkenone C6H8O 96 \ 0.3 \ 45 2,5-Dimethylfuran C6H8O 96 \ 1.24 \ 46 2-Amino-1,3,5-triazine C3H4N4 96 \ \ 0.27 47 2,3-Diazabicyclo[2.2.1]-hept-2-ene decanols C5H8N2 96 \ \ 5.13 48 Furfuryl alcohol C5H6O2 98 2.55 2.75 \ 49 1,3-Cyclopentadione C5H6O2 98 3.12 \ \ 50 1,2-Cyclopentadione C5H6O2 98 \ 1.51 \ 51 2-Ethylene-3-vinyl epoxy-ethane C6H10O 98 0.41 \ \ 52 Ethyl cyanoformate C4H5NO2 99 \ 0.21 \ 53 3-Amino-5-hydroxypyrazole C3H5N3O 99 \ 0.22 \ 54 2-Methyl-2-pentene-1-alcohol C6H12O 100 0.5 \ \ 55 2,3-Glutaric ketone C5H8O2 100 2.53 0.27 \ 56 2-Methyl-3-pentone C6H12O 100 0.29 0.54 \ 57 Tetrahydro-2H-pyran-3-ketone C5H8O2 100 0.47 0.52 \ 58 Succinic anhydride C4H4O3 100 \ \ 0.05 59 2, 2-Dimethyl-1-butanol C6H14O 102 \ 0.37 \ 60 Methyl pyruvate C4H6O3 102 2.68 \ \ 61 Acetic anhydride C4H6O3 102 0.78 \ \ 62 M-Cresol C7H8O 108 0.22 0.21 \ 63 2-Acetylpyrrole C6H7NO 109 0.18 0.25 \ 64 2, 3-Diaminopyridine C5H7N3 109 \ \ 0.24 65 2H-Tetrazole-2-ethyl acetonitrile C3H3N5 109 \ 0.41 \ 66 5-Methylfurfural C6H6O2 110 0.61 0.86 \ 67 2,3-Dimethyl-2-cyclopentene-1-ketone C7H10O 110 \ 0.16 \ 68 2-Acetylfuran C6H6O2 110 \ 0.19 \ 69 2-Amino-3-hydroxypyridine C5H6N2O 110 \ \ 0.07 70 Isocytosine C4H5N3O 111 0.23 \ \ 71 3-Hydroxypyridine-N-oxide C5H5NO2 111 \ \ 0.39 72 N-Ethylidene-1-pyrrolidine C6H12N2 112 \ \ 0.83

Molecular weight

Larch Area % PBL


No. Name Molecular

151 2<sup>0</sup> ,4<sup>0</sup>


DOI: http://dx.doi.org/10.5772/intechopen.81522

161 Ethyl-4-(acetylamino)-1,2,5-oxadiazole-3-

162 11-Methyl-12-methylene-tricyclic [5.3.1.1 (2,6)]-dodecane-11-alcohol

164 2,5,5,8a-Tetramethylmethyl-4-methylene-4a,5,6,7,8,8a-hexahydrogen-4h-chromene

168 3,5-Dimethyl-1-phenyl-1H-pyrazol-4-

169 8-Methoxy[1]benzofuran and [3,2-d] pyrimidine �4(3H)-ketone

170 3,3,4-Trimethyl-4-(4-methylphenyl)

174 2-(1,3-Dihydrogen-2h-indene-2-subunit)- 2,3-dihydrogen-1h-indene-1-ketone

178 (13R)-8a,13:9a,13-Diepoxy-15,16-

benzopyran-6-ketone

179 3,4,8-Trimethoxy-6H-benzophenol[c]

180 1-Naphthalenepropanol,.alpha.-ethenyldec ahydro-.alpha.,5,5,8a-tetramethyl-2 methylene-,[1S-[1.alpha.(R\*),4a.beta.,8a.

dinorlabdane

alpha.]]-

55

carboxylic acid

cyclopentyl alcohol

carboxylate

formula


150 4-Hydroxyl-3-methoxyphenylacetone C10H12O3 180 1.07 0.77 \

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

152 Homovanillic acid C9H10O4 182 \ 2.15 \ 153 Vanillin ethyl ether C10H14O3 182 1.72 \ \ 154 1-Tridecene C13H26 182 \ 0.09 \ 155 γ-Dodecane acid lactone C11H20O2 184 0.71 \ \ 156 6-Dodecyl alcohol C12H26O 186 \ 0.09 \ 157 Tetraethylene glycol C8H18O5 194 \ \ 0.05 158 4-Allyl-2,6-dimethoxyphenol C11H14O3 194 0.57 0.16 \ 159 α-Methyl glucoside C7H14O6 194 \ 0.21 \ 160 2,3-Dimethyl-2-(3-oxobutyl)cyclohexanone C12H20O2 196 \ 0.48 \

163 Eugenol acetate C12H14O3 206 0.34 \ \

165 Ethyl oxalate C11H14O4 210 \ 0.17 \ 166 Tetradecyl alcohol C14H30O 214 \ \ 0.16 167 10-Oxo-dodecane acid C12H22O3 214 0.16 \ \

171 Cubenol C15H26O 222 0.28 \ \ 172 7-Pentadecanone C15H30O 226 \ 0.29 \ 173 Pentaethylene glycol C10H22O6 238 \ \ 0.52

175 (Z)-14-Methyl-8-hexadecene-1-acetal C17H32O 252 \ 0.08 \ 176 Palmitic acid C16H32O2 256 \ 0.22 \ 177 Dibutyl phthalate C16H22O4 278 \ 0.11 \

181 12-Hydroxyandrostane-17-ketone C19H30O2 290 0.31 \ \

Molecular weight

C7H9N3O4 199 0.53 \ \

C14H22O 206 0.47 \ \

C14H22O 206 0.17 \ \

C12H12N2O2 216 0.15 \ \

C11H8N2O3 216 0.15 0.12 \

C15H22O 218 0.38 \ \

C18H14O 246 0.18 \ \

C18H30O2 278 0.14 \ \

C16H14O5 286 0.18 \ \

C20H34O 290 \ 0.29 \

Larch Area % PBL


Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

No. Name Molecular

115 4-Amino-N-hydroxy-1,2, 5-oxadiazole-3-

116 N-(2-Hydroxyethyl) hexahydrogen-1H-

132 4-Methyl-5-(5-methyl-1H-pyrazol-3-base)-

147 1,3,4-Trimethyl-1,7-dihydrogen-6H-pyrazole and pyridine-6-ketone [3,4-b]

54

1H-1,2,3-triazole

carboxyamide

Analytical Pyrolysis

acheptylamine

formula

113 Nonyl aldehyde C9H18O 142 1.02 \ \ 114 4-Ethyl-2,2-dimethylhexane C10H22 142 0.32 \ \

117 2-Methoxy-4-vinyl phenol C9H10O2 150 3.08 \ \ 118 4-Hydroxy-3-methyl acetophenone C9H10O2 150 \ 3.48 \ 119 4-Ethyl guaiacol C9H12O2 152 1.38 2.43 \ 120 Vanillin C8H8O3 152 1.02 \ \ 121 Isoflavin/isovanillin C8H8O3 152 \ 0.11 \ 122 2,6-Dimethoxyphenol C8H10O3 154 0.46 \ \ 123 3,4-Dimethoxyphenol C8H10O3 154 \ 0.21 \ 124 Ethyl 2-heptynoate C9H14O2 154 \ 0.64 \ 125 Valdetamide C9H17NO 155 0.55 \ \ 126 Decanal C10H20O 156 0.2 \ \ 127 Ethyl-2-piperidine formate C8H15NO2 157 0.85 \ \ 128 4-Butyryl morpholine C8H15NO2 157 \ 0.54 \ 129 2-Hydroxy cyclohexyl ester C8H14O3 158 0.26 \ \ 130 1,6-Anhydride-B-D-pyran glucose C6H10O5 162 6.05 1.05 \ 131 1-[(1E)-1-Butenyl]-4-methoxybenzene C11H14O 162 0.2 \ \

133 Eugenol C10H12O2 164 1.32 1.81 \ 134 Cis-isoeugenol C10H12O2 164 4.96 1.15 \ 135 2,3-Dihydro-2,2-dimethyl-7-benzofuranol C10H12O2 164 0.15 \ \ 136 (E)-Isoeugenol C10H12O2 164 \ 5.22 \ 137 3-Allyl-6-methoxyphenol C10H12O2 164 \ 0.19 \ 138 3,4-Dimethoxystyrene C10H12O2 164 \ 0.1 \ 139 Dihydroeugenol C10H14O2 166 0.41 1.04 \ 140 Vanilla ethyl ketone C9H10O3 166 0.72 1.08 \ 141 4-Methoxy-3-hydroxyacetophenone C9H10O3 166 0.33 \ \ 142 High vanillin alcohol C9H12O3 168 0.44 \ \ 143 3-Hydroxyl-4-methoxybenzoic acid C8H8O4 168 0.18 \ \ 144 Vanillic acid C8H8O4 168 0.33 \ \ 145 6-Hydroxy 5-decanone C10H20O2 172 0.42 \ \ 146 2-Heptyl-1,3-dioxy-amyl ring C10H20O2 172 \ \ 0.29

148 Coniferyl alcohol C10H12O3 180 1.96 1 \ 149 2,5-Dimethoxyl-4-toluene formaldehyde C10H12O3 180 0.4 \ \

Molecular weight

C3H5N5O2 143 0.94 \ \

C8H17NO 143 \ \ 0.89

C7H9N5 163 \ 0.25 \

C9H11N3O 177 \ 0.31 \

Larch Area % PBL

#### Analytical Pyrolysis


References

[1] Bridgwater AV, Peacocke GVC. Fast

DOI: http://dx.doi.org/10.5772/intechopen.81522

medium-density fiberboard and particle

345-352. DOI: 10.1016/j.jiec.2015.09.008

[9] Sheldona RA, Sanders JPM. Toward concise metrics for the production of chemicals from renewable biomass. Catalysis Today. 2015;239:3-6. DOI: 10.1016/j.cattod.2014.03.032

[10] Park Y-K, Choi SJ, Jeon J-K, Park SH, Ryoo R, Kim J, et al. Catalytic conversion of waste particle board to bio-oil using nanoporous catalyst. Journal of Nanoscience and

Nanotechnology. 2012;12:5367-5372.

[11] Lee HW, Choi SJ, Jeon J-K, Park SH,

conversion of waste particle board and polypropylene over H-beta and HY zeolites. Renewable Energy. 2015;79:

[12] Kim H, Choi SJ, Kim JM, Jeon J-K, Park SH, Jung S-C, et al. Catalytic copyrolysis of particle board and polypropylene over Al-MCM-48. Materials Research Bulletin. 2016;82: 61-66. DOI: 10.1016/j.materresbull.

[13] Jin B-B, Heo HS, Ryu C, Kim S-S, Jeon J-K, Park Y-K. The copyrolysis of block polypropylene with particle board and medium density fiber. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects. 2014;36: 958-965. DOI: 10.1080/15567036.

[14] Bridgwater AV. Principles and practice of biomass fast pyrolysis processes for liquids. Journal of

Analytical and Applied Pyrolysis. 1999; 51:3-22. DOI: 10.1016/S0165-2370(99)

DOI: 10.1166/jnn.2012.6412

Jung S-C, Park Y-K. Catalytic

9-13. DOI: 10.1016/j.renene.

2014.07.040

2016.03.009

2010.551263

00005-4

board. Journal of Industrial and Engineering Chemistry. 2015;32:

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials

[2] Mohan D, Pittman CU, Steele PH. Pyrolysis of wood/biomass for bio-oil: A critical review. Energy & Fuels. 2006; 20:848-889. DOI: 10.1021/ef0502397

[3] Choi SJ, Park SH, Jeon J-K, Lee IG,

[4] Yanik J, Kornmayer C, Saglam M, Yüksel M. Fast pyrolysis of agricultural wastes: Characterization of pyrolysis products. Fuel Processing Technology. 2007;88:942-947. DOI: 10.1016/j.

[5] Deng N, Zhang Y-F, Wang Y. Thermogravimetric analysis and kinetic study on pyrolysis of representative medical waste composition. Waste Management. 2008;28:1572-1580. DOI:

10.1016/j.wasman.2007.05.024

[6] López A, de MI, Caballero BM, Laresgoiti MF, Adrados A. Pyrolysis of municipal plastic wastes: Influence of raw material composition. Waste Management. 2010;30:620-627. DOI: 10.1016/j.wasman.2009.10.014

[7] Manzano-Agugliaro F, Alcayde A, Montoya FG, Zapata-Sierra A, Gil C. Scientific production of renewable energies worldwide: An overview. Renewable and Sustainable Energy Reviews. 2013;18:134-143. DOI: 10.1016/j.rser.2012.10.020

[8] Han TU, Kim Y-M, Watanabe C, Teramae N, Park Y-K, Kim S, et al. Analytical pyrolysis properties of waste

57

Ryu C, Suh DJ, et al. Catalytic conversion of particle board over microporous catalysts. Renewable Energy. 2013;54:105-110. DOI: 10.1016/

j.renene.2012.08.050

fuproc.2007.05.002

pyrolysis processes for biomass. Renewable & Sustainable Energy Reviews. 2000;4:1-73. DOI: 10.1016/

S1364-0321(99)00007-6

### Author details

Liuming Song, Xiao Ge, Xueyong Ren, Wenliang Wang, Jianmin Chang and Jinsheng Gou\* Key Laboratory of Wooden Material Science and Application, College of Materials Science and Technology, Beijing Forestry University, Ministry of Education, Beijing, China

\*Address all correspondence to: jinsheng@bjfu.edu.cn

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Release Profile of Nitrogen during Thermal Treatment of Waste Wooden Packaging Materials DOI: http://dx.doi.org/10.5772/intechopen.81522

#### References

No. Name Molecular

182 5,8-Diethoxy-3-(methoxy carbonyl)-2 quinoline carboxylic acid


,4,4'-tetraone

188 3<sup>0</sup> ,8,8<sup>0</sup>

Analytical Pyrolysis

Author details

and Jinsheng Gou\*

Beijing, China

56

binaphthalene-1,1<sup>0</sup>

formula

183 Di-N-decyl ether C20H42O 298 \ 0.27 \ 184 Vitamin A acetate C22H32O2 328 \ 0.73 \ 185 Tetracosane C24H50 338 \ 0.1 \ 186 14-Heptacosanone C27H54O 394 0.25 \ \ 187 Lanosterol C30H50O 426 \ 0.28 \

Liuming Song, Xiao Ge, Xueyong Ren, Wenliang Wang, Jianmin Chang

\*Address all correspondence to: jinsheng@bjfu.edu.cn

provided the original work is properly cited.

Key Laboratory of Wooden Material Science and Application, College of Materials Science and Technology, Beijing Forestry University, Ministry of Education,

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Molecular weight

C15H16N2O6 296 0.36 \ \

C28H25NO7 487 \ 0.34 \

Larch Area % PBL UF

[1] Bridgwater AV, Peacocke GVC. Fast pyrolysis processes for biomass. Renewable & Sustainable Energy Reviews. 2000;4:1-73. DOI: 10.1016/ S1364-0321(99)00007-6

[2] Mohan D, Pittman CU, Steele PH. Pyrolysis of wood/biomass for bio-oil: A critical review. Energy & Fuels. 2006; 20:848-889. DOI: 10.1021/ef0502397

[3] Choi SJ, Park SH, Jeon J-K, Lee IG, Ryu C, Suh DJ, et al. Catalytic conversion of particle board over microporous catalysts. Renewable Energy. 2013;54:105-110. DOI: 10.1016/ j.renene.2012.08.050

[4] Yanik J, Kornmayer C, Saglam M, Yüksel M. Fast pyrolysis of agricultural wastes: Characterization of pyrolysis products. Fuel Processing Technology. 2007;88:942-947. DOI: 10.1016/j. fuproc.2007.05.002

[5] Deng N, Zhang Y-F, Wang Y. Thermogravimetric analysis and kinetic study on pyrolysis of representative medical waste composition. Waste Management. 2008;28:1572-1580. DOI: 10.1016/j.wasman.2007.05.024

[6] López A, de MI, Caballero BM, Laresgoiti MF, Adrados A. Pyrolysis of municipal plastic wastes: Influence of raw material composition. Waste Management. 2010;30:620-627. DOI: 10.1016/j.wasman.2009.10.014

[7] Manzano-Agugliaro F, Alcayde A, Montoya FG, Zapata-Sierra A, Gil C. Scientific production of renewable energies worldwide: An overview. Renewable and Sustainable Energy Reviews. 2013;18:134-143. DOI: 10.1016/j.rser.2012.10.020

[8] Han TU, Kim Y-M, Watanabe C, Teramae N, Park Y-K, Kim S, et al. Analytical pyrolysis properties of waste medium-density fiberboard and particle board. Journal of Industrial and Engineering Chemistry. 2015;32: 345-352. DOI: 10.1016/j.jiec.2015.09.008

[9] Sheldona RA, Sanders JPM. Toward concise metrics for the production of chemicals from renewable biomass. Catalysis Today. 2015;239:3-6. DOI: 10.1016/j.cattod.2014.03.032

[10] Park Y-K, Choi SJ, Jeon J-K, Park SH, Ryoo R, Kim J, et al. Catalytic conversion of waste particle board to bio-oil using nanoporous catalyst. Journal of Nanoscience and Nanotechnology. 2012;12:5367-5372. DOI: 10.1166/jnn.2012.6412

[11] Lee HW, Choi SJ, Jeon J-K, Park SH, Jung S-C, Park Y-K. Catalytic conversion of waste particle board and polypropylene over H-beta and HY zeolites. Renewable Energy. 2015;79: 9-13. DOI: 10.1016/j.renene. 2014.07.040

[12] Kim H, Choi SJ, Kim JM, Jeon J-K, Park SH, Jung S-C, et al. Catalytic copyrolysis of particle board and polypropylene over Al-MCM-48. Materials Research Bulletin. 2016;82: 61-66. DOI: 10.1016/j.materresbull. 2016.03.009

[13] Jin B-B, Heo HS, Ryu C, Kim S-S, Jeon J-K, Park Y-K. The copyrolysis of block polypropylene with particle board and medium density fiber. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects. 2014;36: 958-965. DOI: 10.1080/15567036. 2010.551263

[14] Bridgwater AV. Principles and practice of biomass fast pyrolysis processes for liquids. Journal of Analytical and Applied Pyrolysis. 1999; 51:3-22. DOI: 10.1016/S0165-2370(99) 00005-4

[15] Babu BV. Biomass pyrolysis: A stateof-the-art review. Biofuels, Bioproducts and Biorefining: Innovation for a Sustainable Economy. 2008;2:393-414. DOI: 10.1002/bbb

[16] Zhang Y, He ZB, Xue L, Chu DM, Mu J. Influence of a urea-formaldehyde resin adhesive on pyrolysis characteristics and volatiles emission of poplar particleboard. RSC Advances. 2016;6:12850-12861. DOI: 10.1039/ c5ra18068f

**59**

**Chapter 4**

**Abstract**

biomass

**1. Introduction**

more and more international conflicts [1].

Hydrocarbonization. Does

*Silvia Román, Beatriz Ledesma, Andrés Álvarez-Murillo,* 

In this work, we aim to evaluate the potential of hydrothermal carbonization (also known as wet pyrolysis) as a pretreatment, by evaluating the changes induced in the raw material (cellulose) under varying experimental conditions. Hydrocarbonization processes were performed under different temperature, time and biomass/water ratios following a response surface methodology. The hydrochars obtained were characterized in terms of proximate analysis, behavior towards pyrolysis and combustion, heating value and surface textural and chemical features. The presence of typical hydrocarbonization reactions (dehydration, hydrolysis, decarboxylation, decarbonylation, recondensation, etc.) was only possible if a limit temperature (200°C) was used. Under these conditions, proximate analyses changed, the surface chemistry was modified, and the formation of a second lignite-type solid fraction was observed.

**Keywords:** hydrocarbonization, wet pyrolysis, cellulose, drying, energy efficiency,

As the consequences of the massive use of fossil fuels are more and more worrying, national and international strategies are pointing out the clear and immediate need of shifting the current energy supply infrastructures towards more environmental friendly and sustainable models. Geopolitical conflicts due to dependency relations between countries, next depletion and climate change issues involve a severe reality that is at the moment causing wars, increasing human inequality, jeopardizing food security and triggering human relocation processes, which cause

One purposeful renewable energy source with proven potential to provide heat or biofuels is biomass. Estimates conclude that a shift to biological raw materials could save up to 2.5 billion tons of CO2 equivalent per year by 2030, increasing markets for bio-based raw materials and new consumer products several-fold [2]. Regarding biomass sources, their abundance and availability, decentralization, ease to extract and handle and heating value are very precious features. There are, however, some issues that limit the use of some biomass resources, as for

*Eduardo Sabio, J. F. González, Mara Olivares-Marín* 

It Worth to Be Called a

Pretreatment?

*and Mouzaina Boutieb*

#### **Chapter 4**

[15] Babu BV. Biomass pyrolysis: A stateof-the-art review. Biofuels, Bioproducts and Biorefining: Innovation for a Sustainable Economy. 2008;2:393-414.

[16] Zhang Y, He ZB, Xue L, Chu DM, Mu J. Influence of a urea-formaldehyde

characteristics and volatiles emission of poplar particleboard. RSC Advances. 2016;6:12850-12861. DOI: 10.1039/

resin adhesive on pyrolysis

DOI: 10.1002/bbb

Analytical Pyrolysis

c5ra18068f

58

## Hydrocarbonization. Does It Worth to Be Called a Pretreatment?

*Silvia Román, Beatriz Ledesma, Andrés Álvarez-Murillo, Eduardo Sabio, J. F. González, Mara Olivares-Marín and Mouzaina Boutieb*

#### **Abstract**

In this work, we aim to evaluate the potential of hydrothermal carbonization (also known as wet pyrolysis) as a pretreatment, by evaluating the changes induced in the raw material (cellulose) under varying experimental conditions. Hydrocarbonization processes were performed under different temperature, time and biomass/water ratios following a response surface methodology. The hydrochars obtained were characterized in terms of proximate analysis, behavior towards pyrolysis and combustion, heating value and surface textural and chemical features. The presence of typical hydrocarbonization reactions (dehydration, hydrolysis, decarboxylation, decarbonylation, recondensation, etc.) was only possible if a limit temperature (200°C) was used. Under these conditions, proximate analyses changed, the surface chemistry was modified, and the formation of a second lignite-type solid fraction was observed.

**Keywords:** hydrocarbonization, wet pyrolysis, cellulose, drying, energy efficiency, biomass

#### **1. Introduction**

As the consequences of the massive use of fossil fuels are more and more worrying, national and international strategies are pointing out the clear and immediate need of shifting the current energy supply infrastructures towards more environmental friendly and sustainable models. Geopolitical conflicts due to dependency relations between countries, next depletion and climate change issues involve a severe reality that is at the moment causing wars, increasing human inequality, jeopardizing food security and triggering human relocation processes, which cause more and more international conflicts [1].

One purposeful renewable energy source with proven potential to provide heat or biofuels is biomass. Estimates conclude that a shift to biological raw materials could save up to 2.5 billion tons of CO2 equivalent per year by 2030, increasing markets for bio-based raw materials and new consumer products several-fold [2].

Regarding biomass sources, their abundance and availability, decentralization, ease to extract and handle and heating value are very precious features. There are, however, some issues that limit the use of some biomass resources, as for

example, their high moisture content, which involves the implementation of costintensive drying pretreatments before classical thermochemical processes such as pyrolysis, combustion or gasification.

One pretreatment that has recently gained prominence is hydrocarbonization (HTC) or wet pyrolysis, that is, the thermochemical conversion of biomass in hot compressed water under relatively low temperature and self-generated pressure. In this way, biomass moisture is not a downside, but takes a role in the reaction both as solvent and as catalyst, triggering the reaction. Because of this important advantage as well as other additional features related to the final product quality, ease, low cost or process energy efficiency, this technique has gained relevance during last years. Because of the abovementioned advantages, HTC processes have been more and more used during last years and researchers have mainly focused their attention on (a) studying it as a previous reactions step for other processes, or (b) investigating HTC as a process to yield a material suitable for specific applications such as biofuel, adsorbent, soil amendment or catalyst [3].

In previous works, we studied the potential of HTC processes to upgrade tomato peel, olive pomace and orange peel [4–6]. Other authors have addressed the HTC of other humid materials such as waste streams [7], grape pomace [8] or potato peel [9]. In this work, we aim to evaluate the changes induced by HTC on pure cellulose that can affect to their further use in other thermochemical processes. Based on the experimental results obtained by HTC under varying experimental conditions, as well as the results found in the bibliography, we aim to offer insight about the chemical and structural changes induced as a result of the process, and their potential influence in further processing of the raw material.

#### **2. Experimental**

#### **2.1 Hydrocarbonization experiments**

Microcrystalline cellulose (Sigma-Aldrich) was dried at 105°C until constant weight and then stored in closed flasks placed in desiccators for further analysis.

The HTC processes were performed in a stainless steel autoclave (Berghof, Germany). In a 0.2 L Teflon vessel (unstirred), an appropriate amount of sample (5–18.4 g) and 150 mL of deionized water at room temperature were added, in order to obtain the targeted biomass/water ratio, R (1.1–12.3%). Then, the Teflon vessel was sealed and placed into the autoclave and the system remained overnight at room temperature. Thereafter, the system was heated up in an electric furnace at selected temperatures (150–250°C), during a chosen processing time (3.2–36.8 h). The experimental conditions were designed according to the response surface methodology, as described elsewhere [5]. Following this procedure, 18 runs were performed (15 under different conditions, and 3 additional runs at one particular condition to test experimental variability, as stated by the method).

The reactor pressure was always at or slightly above the water vapor pressure. After the reaction, the system was cooled down using an ice bath and then the autoclave was opened and the solid product (Hydrochar, HC) was obtained by vacuum filtration (Whatman filter paper number 3). Then, the HCs were dried for 24 h and stored in a desiccator for further analysis.

#### **2.2 Characterization of hydrochars**

Both pure cellulose and derived HCs were characterized in terms of their proximate analysis (% wt./wt.) following the technical specifications CEN/TS 1474–2,

**61**

*Hydrocarbonization. Does It Worth to Be Called a Pretreatment?*

to analysis. Results are reported on a dry, ash-free (daf) basis.

**3.1 HC characterization and thermal degradation study**

CEN/TS 15148 and CEN/TS 14775 for moisture (M), volatile matter (VM) and ash (A), respectively. Fixed carbon was determined by difference (100-M-VM-A). The thermogravimetric behavior of the raw material and the derived HCs was studied under both air and nitrogen atmospheres, using a thermobalance (TA Instruments) using a heating rate of 10°C min−1 and a gas flow of 100 mL min−1 in both cases, as described elsewhere [10]. In order to get further knowledge on the thermal degradation profiles, selected samples were analyzed by coupled thermogravimetric and mass spectrometry analysis (TG/MS, thermogravimetric system, TA Instruments; Mass Spectrometer, Pfeiffer Tecnovac Thermostar GDS301 T3). The gas line between the TG and MS was heated to 200°C in order to avoid cold points and thus preventing the condensation of some of the gaseous products. The mass/charge ratios (m/z) 44 and 16 were assigned, respectively, to CO2 and CH4, respectively. The higher heating value (HHV) of solid samples was measured in a Parr 1241 adiabatic oxygen bomb calorimeter (Moline, IL) fitted with continuous temperature recording. HTC biochar samples of 0.4–0.5 g were dried at 105°C for 24 h prior

Surface morphology studies were carried out by scanning electron microscopy with coupled X-Ray Electron dispersion (SEM–EDX, Quanta 3D FEG, FEI). The samples were prepared by depositing about 50 mg of sample on an aluminum stud covered with conductive adhesive carbon tapes, and then coated with Rh-Pd for 1 min to prevent charging during observations. Imaging was done in the high vacuum mode at an accelerating voltage of 30 kV, using secondary electrons under

The surface chemistry of the hydrochars was studied by FTIR spectroscopy. FTIR spectra were recorded with a PerkinElmer model Paragon 1000 PC spectrophotometer, using the KBr disc method, with a resolution of 4 cm−1 and 100 scans.

**Table 1** lists the elemental and proximate analysis of the HCs, as well as the

Two dissimilar HC behaviors were identified from the immediate analyses. On the one hand, one can find HCs with volatile content higher than 85%, indicative of negligible HTC and, on the other hand, samples in which the process readily took place and brought up a clear decrease on volatile matter, with fixed carbon values higher than 50%. Dehydration and decarboxylation are well-known HTC mechanisms, bringing up an expected decrease in moisture and volatile matter content. From our results, both effects are clear although the prominence of them is clearly affected by the experimental conditions; as previously suggested, it seems that there is a cutting point that delimitates when HTC is really taking place. Moreover, it seems that this cutting point is determined by the temperature, whereas time has a slight influence and the biomass/water ratio does not have an effect on its location. According to the bibliography, biomass starts its decomposition in the presence of water, only when particular subcritical conditions are reached, and water behaves as a non-polar solvent and can therefore make biomass constituents become soluble [11]. Under these conditions, the properties of water such as the ionic constant readily change (it has been reported as being nearly two orders of magnitude higher than at room temperature) [12]. The temperature and pressure defining these conditions is controversial and has been reported as low as 170°C

*DOI: http://dx.doi.org/10.5772/intechopen.79477*

high vacuum conditions.

**3. Discussion of results**

corresponding SY and HHV values.

[13] or as high as 220°C [14].

#### *Hydrocarbonization. Does It Worth to Be Called a Pretreatment? DOI: http://dx.doi.org/10.5772/intechopen.79477*

*Analytical Pyrolysis*

**2. Experimental**

pyrolysis, combustion or gasification.

adsorbent, soil amendment or catalyst [3].

**2.1 Hydrocarbonization experiments**

stored in a desiccator for further analysis.

**2.2 Characterization of hydrochars**

potential influence in further processing of the raw material.

condition to test experimental variability, as stated by the method).

example, their high moisture content, which involves the implementation of costintensive drying pretreatments before classical thermochemical processes such as

One pretreatment that has recently gained prominence is hydrocarbonization (HTC) or wet pyrolysis, that is, the thermochemical conversion of biomass in hot compressed water under relatively low temperature and self-generated pressure. In this way, biomass moisture is not a downside, but takes a role in the reaction both as solvent and as catalyst, triggering the reaction. Because of this important advantage as well as other additional features related to the final product quality, ease, low cost or process energy efficiency, this technique has gained relevance during last years. Because of the abovementioned advantages, HTC processes have been more and more used during last years and researchers have mainly focused their attention on (a) studying it as a previous reactions step for other processes, or (b) investigating HTC as a process to yield a material suitable for specific applications such as biofuel,

In previous works, we studied the potential of HTC processes to upgrade tomato peel, olive pomace and orange peel [4–6]. Other authors have addressed the HTC of other humid materials such as waste streams [7], grape pomace [8] or potato peel [9]. In this work, we aim to evaluate the changes induced by HTC on pure cellulose that can affect to their further use in other thermochemical processes. Based on the experimental results obtained by HTC under varying experimental conditions, as well as the results found in the bibliography, we aim to offer insight about the chemical and structural changes induced as a result of the process, and their

Microcrystalline cellulose (Sigma-Aldrich) was dried at 105°C until constant weight and then stored in closed flasks placed in desiccators for further analysis. The HTC processes were performed in a stainless steel autoclave (Berghof, Germany). In a 0.2 L Teflon vessel (unstirred), an appropriate amount of sample (5–18.4 g) and 150 mL of deionized water at room temperature were added, in order to obtain the targeted biomass/water ratio, R (1.1–12.3%). Then, the Teflon vessel was sealed and placed into the autoclave and the system remained overnight at room temperature. Thereafter, the system was heated up in an electric furnace at selected temperatures (150–250°C), during a chosen processing time (3.2–36.8 h). The experimental conditions were designed according to the response surface methodology, as described elsewhere [5]. Following this procedure, 18 runs were performed (15 under different conditions, and 3 additional runs at one particular

The reactor pressure was always at or slightly above the water vapor pressure. After the reaction, the system was cooled down using an ice bath and then the autoclave was opened and the solid product (Hydrochar, HC) was obtained by vacuum filtration (Whatman filter paper number 3). Then, the HCs were dried for 24 h and

Both pure cellulose and derived HCs were characterized in terms of their proximate analysis (% wt./wt.) following the technical specifications CEN/TS 1474–2,

**60**

CEN/TS 15148 and CEN/TS 14775 for moisture (M), volatile matter (VM) and ash (A), respectively. Fixed carbon was determined by difference (100-M-VM-A).

The thermogravimetric behavior of the raw material and the derived HCs was studied under both air and nitrogen atmospheres, using a thermobalance (TA Instruments) using a heating rate of 10°C min−1 and a gas flow of 100 mL min−1 in both cases, as described elsewhere [10]. In order to get further knowledge on the thermal degradation profiles, selected samples were analyzed by coupled thermogravimetric and mass spectrometry analysis (TG/MS, thermogravimetric system, TA Instruments; Mass Spectrometer, Pfeiffer Tecnovac Thermostar GDS301 T3). The gas line between the TG and MS was heated to 200°C in order to avoid cold points and thus preventing the condensation of some of the gaseous products. The mass/charge ratios (m/z) 44 and 16 were assigned, respectively, to CO2 and CH4, respectively.

The higher heating value (HHV) of solid samples was measured in a Parr 1241 adiabatic oxygen bomb calorimeter (Moline, IL) fitted with continuous temperature recording. HTC biochar samples of 0.4–0.5 g were dried at 105°C for 24 h prior to analysis. Results are reported on a dry, ash-free (daf) basis.

Surface morphology studies were carried out by scanning electron microscopy with coupled X-Ray Electron dispersion (SEM–EDX, Quanta 3D FEG, FEI). The samples were prepared by depositing about 50 mg of sample on an aluminum stud covered with conductive adhesive carbon tapes, and then coated with Rh-Pd for 1 min to prevent charging during observations. Imaging was done in the high vacuum mode at an accelerating voltage of 30 kV, using secondary electrons under high vacuum conditions.

The surface chemistry of the hydrochars was studied by FTIR spectroscopy. FTIR spectra were recorded with a PerkinElmer model Paragon 1000 PC spectrophotometer, using the KBr disc method, with a resolution of 4 cm−1 and 100 scans.

#### **3. Discussion of results**

#### **3.1 HC characterization and thermal degradation study**

**Table 1** lists the elemental and proximate analysis of the HCs, as well as the corresponding SY and HHV values.

Two dissimilar HC behaviors were identified from the immediate analyses. On the one hand, one can find HCs with volatile content higher than 85%, indicative of negligible HTC and, on the other hand, samples in which the process readily took place and brought up a clear decrease on volatile matter, with fixed carbon values higher than 50%. Dehydration and decarboxylation are well-known HTC mechanisms, bringing up an expected decrease in moisture and volatile matter content. From our results, both effects are clear although the prominence of them is clearly affected by the experimental conditions; as previously suggested, it seems that there is a cutting point that delimitates when HTC is really taking place. Moreover, it seems that this cutting point is determined by the temperature, whereas time has a slight influence and the biomass/water ratio does not have an effect on its location.

According to the bibliography, biomass starts its decomposition in the presence of water, only when particular subcritical conditions are reached, and water behaves as a non-polar solvent and can therefore make biomass constituents become soluble [11]. Under these conditions, the properties of water such as the ionic constant readily change (it has been reported as being nearly two orders of magnitude higher than at room temperature) [12]. The temperature and pressure defining these conditions is controversial and has been reported as low as 170°C [13] or as high as 220°C [14].


#### **Table 1.**

*Values for solid yield (SY, %), proximate analysis (%) and high heating value (HHV) (kJ/kg), for reactions made under different Ratio (%), temperature (T), time (t).*

The interpretation of the results showed in **Table 1** can be facilitated by plotting 2D level curves for a fixed value of one variable. As an example, **Figure 1** shows these plots for fixed biomass/water ratios (a–c), fixed temperature values (d–f) and fixed time periods (g–i), when the output function is the solid yield (%). A glance to these figures can provide valuable information not only about the effect of the experimental variables but also on their interactions, as it is explained next.

First, it can be observed that for a fixed ratio, increasing temperature involves a lower SY, up to a cutting point for which the process is reversed; this suggests, in coherence with results reported by other researchers, that the presence of reactions responsible for the formation of aggregates from monomers in the liquid phase, that finally migrate to the solid phase might be only possible if a certain temperature is used. Funke et al. [15] identify this effect with the reach of a critical saturation concentration, by which the cellulose fragments (produced from dehydration or decarboxylation, both endothermal processes) react to form cross-linked hydrophobic polymer structures. It is also interesting to notice that this effect is mitigated when a greater ratio is used; probably because of diffusion restrictions. Dissimilarly, for a fixed ratio, time has a scant influence under these conditions.

On the other hand, one can see that for a fixed temperature increasing *R* brings out an increase on the solid yield. Besides, time has a positive influence on the solid yield only if the fixed temperature is low, whereas the tendency is inverted if a high temperature is employed.

If **t** is fixed, a higher **T** decreases the solid yield, up to a maximum value of SY; thereafter, if T is increased, the SY is also enhanced. This temperature value is always higher than 200°C, and decreases for longer treatments. The ratio has a scant influence on the SY for low temperatures and a positive effect on it a higher temperatures.

**63**

above.

**Figure 1.**

*Hydrocarbonization. Does It Worth to Be Called a Pretreatment?*

**Figure 2a** and **b** depicts the results obtained from the thermal degradation studies under inert and oxidizing atmosphere, respectively. As it can be inferred from this figure, the first weight loss, associated to moisture, is in general less marked for samples that were hydrocarbonized under more aggressive conditions (and, in all cases, lower than for pure cellulose, see **Table 1**; moisture content of 8.9%), which confirms that HTC was effective as drying process. Hydrolysis and dehydration are, as previously reported, specially favored for higher temperatures. Further on, one can see that the slope of the thermogram step associated to the release of volatile matter is also markedly affected by the experimental conditions. While most of the volatile matter has been degraded for HCs prepared at T > 200°C, the runs made under soft conditions show TG profiles that almost overlap with that of pure cellulose. This behavior has a clear effect on the fixed carbon content, as explained

*Level curves for solid yield corresponding to HTC processes under varying experimental conditions.*

The breaking-up of volatile matter as a result of HTC has been associated to hydrolysis, dehydration, decarboxylation, decarbonylation or demethanation reactions. Besides, some other reactions responsible for the stabilization (and even further creation) of the solid phase have also been reported (namely condensation, polymerization, and aromatization). By having a look to DTG profiles obtained for biomass precursors [14], one could suggest that the higher proportion of lignin in the HCs prepared under more aggressive conditions is responsible for

*DOI: http://dx.doi.org/10.5772/intechopen.79477*

*Hydrocarbonization. Does It Worth to Be Called a Pretreatment? DOI: http://dx.doi.org/10.5772/intechopen.79477*

**Figure 1.**

*Analytical Pyrolysis*

**Ratio % (g/100 ml)** **T (°C)**

*made under different Ratio (%), temperature (T), time (t).*

**t (h)** **SY (%)**

**Raw** — — — — 8.9 88.72 1.75 0.63 17.0 11.7 200 0.9 93.96 1.62 91.77 5.44 1.17 16.99 3.3 230 15.0 29.89 3.51 43.5 52.4 0.57 27.06 20.0 170 4.5 95.63 6.91 88.31 4.32 0.46 16.99 11.7 150 9.8 93.45 7.6 90.02 1.81 0.57 17.34 3.3 170 4.5 94.98 4.84 91.9 1.69 1.57 17.04 3.3 230 4.5 21.72 3.31 49.42 49.96 3.31 25.89 3.3 170 15.0 59.73 2.61 86.18 6.91 4.31 17.30 20.0 170 15.0 83.08 2.88 89.54 7.09 0.49 16.99 25.7 200 9.8 49.47 1.92 47.50 52.5 0.49 26.13 11.7 200 9.8 44.25 0.22 46.36 51.43 1.99 26.42 20.0 230 4.5 46.99 2.59 49.03 44.78 3.74 26.25 20.0 230 15.0 47.80 2.44 43.94 50.81 2.81 27.39 11.7 200 18.6 44.66 2.73 47.89 47.71 1.68 26.65 11.7 200 9.8 44.29 1.57 49.91 44.78 3.74 26.72 1.5 200 9.8 42.02 1.65 46.52 51.83 1.65 26.38

**Moisture (%)**

**Vol. (%)**

**Fixed carbon (%)**

**Ash (%)**

**HHV (MJ/kg)**

**No. run**

**Table 1.**

The interpretation of the results showed in **Table 1** can be facilitated by plotting 2D level curves for a fixed value of one variable. As an example, **Figure 1** shows these plots for fixed biomass/water ratios (a–c), fixed temperature values (d–f) and fixed time periods (g–i), when the output function is the solid yield (%). A glance to these figures can provide valuable information not only about the effect of the experimental variables but also on their interactions, as it is explained next.

*Values for solid yield (SY, %), proximate analysis (%) and high heating value (HHV) (kJ/kg), for reactions* 

First, it can be observed that for a fixed ratio, increasing temperature involves a lower SY, up to a cutting point for which the process is reversed; this suggests, in coherence with results reported by other researchers, that the presence of reactions responsible for the formation of aggregates from monomers in the liquid phase, that finally migrate to the solid phase might be only possible if a certain temperature is used. Funke et al. [15] identify this effect with the reach of a critical saturation concentration, by which the cellulose fragments (produced from dehydration or decarboxylation, both endothermal processes) react to form cross-linked hydrophobic polymer structures. It is also interesting to notice that this effect is mitigated when a greater ratio is used; probably because of diffusion restrictions. Dissimilarly,

On the other hand, one can see that for a fixed temperature increasing *R* brings out an increase on the solid yield. Besides, time has a positive influence on the solid yield only if the fixed temperature is low, whereas the tendency is inverted if a high

If **t** is fixed, a higher **T** decreases the solid yield, up to a maximum value of SY; thereafter, if T is increased, the SY is also enhanced. This temperature value is always higher than 200°C, and decreases for longer treatments. The ratio has a scant influence on the SY for low temperatures and a positive effect on it a higher temperatures.

for a fixed ratio, time has a scant influence under these conditions.

**62**

temperature is employed.

*Level curves for solid yield corresponding to HTC processes under varying experimental conditions.*

**Figure 2a** and **b** depicts the results obtained from the thermal degradation studies under inert and oxidizing atmosphere, respectively. As it can be inferred from this figure, the first weight loss, associated to moisture, is in general less marked for samples that were hydrocarbonized under more aggressive conditions (and, in all cases, lower than for pure cellulose, see **Table 1**; moisture content of 8.9%), which confirms that HTC was effective as drying process. Hydrolysis and dehydration are, as previously reported, specially favored for higher temperatures. Further on, one can see that the slope of the thermogram step associated to the release of volatile matter is also markedly affected by the experimental conditions. While most of the volatile matter has been degraded for HCs prepared at T > 200°C, the runs made under soft conditions show TG profiles that almost overlap with that of pure cellulose. This behavior has a clear effect on the fixed carbon content, as explained above.

The breaking-up of volatile matter as a result of HTC has been associated to hydrolysis, dehydration, decarboxylation, decarbonylation or demethanation reactions. Besides, some other reactions responsible for the stabilization (and even further creation) of the solid phase have also been reported (namely condensation, polymerization, and aromatization). By having a look to DTG profiles obtained for biomass precursors [14], one could suggest that the higher proportion of lignin in the HCs prepared under more aggressive conditions is responsible for

**Figure 2.** *Thermal degradation study (TG and DTA) under inert (a) and oxidizing (b) conditions.*

the gradual mass release at high temperatures during TGA analyses. However, in the case of cellulose, the examination of DTA curves at temperatures higher than 400°C allows concluding that after effective HTC (samples 6, 10 and 12) a solid phase has been created on the HC, which is more resistant than the precursor. This new constituent is accounts approximately for 50% of the HC weight, and degrades in the range of temperature 400–750°C, a temperature range that is associated to *charring* processes [16]. The same trend can be observed from combustion profiles.

Monitorizing the emissions associated to thermal degradation processes can be very useful to confirm the prominence of particular reactions pathways. In this work, the emissions associated to the combustion of selected HCs were studied, and, as an example, **Figure 3** shows the ion intensity profiles found for sample 6, made under aggressive conditions (i.e., under which HTC readily took place). The analysis confirms the release of CO2 along the temperature range associated to the removal of volatile matter, and also, although in a lower extent, at higher temperatures. This in turn is coherent to the existence a fraction of HC that is more resistant to degradation, even under oxidizing conditions, and is the consequence of the aromatization reactions and repolymerization of cellulose fragments, as described previously. CH4 release is also found at temperatures higher than 500°C, supporting the previous behavior.

#### **3.2 HC characterization and thermal degradation study**

The surface morphology of the samples was examined by SEM micrography. For the sake of brevity, only some of them have been included in this work, and have been collected in **Figure 4**, classified in two groups in **Figure 4a**–**e**.

**65**

*Hydrocarbonization. Does It Worth to Be Called a Pretreatment?*

at low temperature, also exhibited these features.

*Emissions associated to the thermal degradation of HC-6.*

using suitable bibliography.

**Figure 3.**

prominent in these cases.

that did not react.

Firstly, one can observe that for sample 1 (a, representative of very mild conditions), the HC surface is smooth and there is presence of some irregular aggregates, which might be associated to the initial steps of cellulose dilution, although the precursor fibrous structure remains almost unchanged. Sample 8 (b), also prepared

In contrast, the appearance of samples prepared at temperatures higher than 200°C (such as 6, 10 and 12) is markedly different (**Figure 4c**–**e**). In these HCs, the surface appears heterogeneous and covered of microspheres of various sizes. The formation of these spheres has been traditionally associated to the breaking-up of cellulose molecules, as found in biomass materials. As a result of hydrolysis, cellulose breaks into small-chain polymers and monomers which further can polymerize as higher molecular weight compounds (is a second solid phase, as it was previously suggested from TG profiles). After hydrolysis (or simultaneously), dehydration is assumed to take place [14]; this process can be both physical (reject of water from the solid precursor) and chemical (removal of hydroxyl groups). The spherical configuration is related to their limited solubility and hydrophobicity, as it minimizes the interfacial surface HC-solvent [17]. The changes induced on the surface chemistry of the HCs were also dependent on the preparation conditions, and, as in the case of the previous analyses, two different trends were found, as a result of a less or more aggressive treatment. **Figure 5** collects the spectra obtained for selected HCs; the assignation of bands was made

As inferred from **Figure 4**, the bands found for HCs 1 and 8 are significantly

In the first place, the bands usually assigned to –OH groups (signals around 3400 and 2800 cm−1) are significantly less intense for those samples hydrocarbonized at higher temperature, suggesting that hydrolysis and dehydration were more

Also, as the HTC temperature is increased there is a decrease on the oxygenated groups present on the HC surface; for instance, the vanishing of the spectral band

A peak at 1264 cm−1, corresponding to the C–O–C bond of cellulose, is clearly found in samples 1 and 8, and remains, also slighter, for the remaining samples, indicating that part of the cellulose was degraded, but there is still a fraction of it

different in size and location to those found for samples 6, 10 and 12.

at 1030 cm−1 suggests the removal of ether-type functional groups (C–O).

*DOI: http://dx.doi.org/10.5772/intechopen.79477*

*Hydrocarbonization. Does It Worth to Be Called a Pretreatment? DOI: http://dx.doi.org/10.5772/intechopen.79477*

#### **Figure 3.**

*Analytical Pyrolysis*

the gradual mass release at high temperatures during TGA analyses. However, in the case of cellulose, the examination of DTA curves at temperatures higher than 400°C allows concluding that after effective HTC (samples 6, 10 and 12) a solid phase has been created on the HC, which is more resistant than the precursor. This new constituent is accounts approximately for 50% of the HC weight, and degrades in the range of temperature 400–750°C, a temperature range that is associated to *charring* processes [16]. The same trend can be observed from

*Thermal degradation study (TG and DTA) under inert (a) and oxidizing (b) conditions.*

Monitorizing the emissions associated to thermal degradation processes can be very useful to confirm the prominence of particular reactions pathways. In this work, the emissions associated to the combustion of selected HCs were studied, and, as an example, **Figure 3** shows the ion intensity profiles found for sample 6, made under aggressive conditions (i.e., under which HTC readily took place). The analysis confirms the release of CO2 along the temperature range associated to the removal of volatile matter, and also, although in a lower extent, at higher temperatures. This in turn is coherent to the existence a fraction of HC that is more resistant to degradation, even under oxidizing conditions, and is the consequence of the aromatization reactions and repolymerization of cellulose fragments, as described previously. CH4 release is also found at temperatures higher than 500°C, supporting

The surface morphology of the samples was examined by SEM micrography. For the sake of brevity, only some of them have been included in this work, and have

**64**

combustion profiles.

**Figure 2.**

the previous behavior.

**3.2 HC characterization and thermal degradation study**

been collected in **Figure 4**, classified in two groups in **Figure 4a**–**e**.

*Emissions associated to the thermal degradation of HC-6.*

Firstly, one can observe that for sample 1 (a, representative of very mild conditions), the HC surface is smooth and there is presence of some irregular aggregates, which might be associated to the initial steps of cellulose dilution, although the precursor fibrous structure remains almost unchanged. Sample 8 (b), also prepared at low temperature, also exhibited these features.

In contrast, the appearance of samples prepared at temperatures higher than 200°C (such as 6, 10 and 12) is markedly different (**Figure 4c**–**e**). In these HCs, the surface appears heterogeneous and covered of microspheres of various sizes. The formation of these spheres has been traditionally associated to the breaking-up of cellulose molecules, as found in biomass materials. As a result of hydrolysis, cellulose breaks into small-chain polymers and monomers which further can polymerize as higher molecular weight compounds (is a second solid phase, as it was previously suggested from TG profiles). After hydrolysis (or simultaneously), dehydration is assumed to take place [14]; this process can be both physical (reject of water from the solid precursor) and chemical (removal of hydroxyl groups). The spherical configuration is related to their limited solubility and hydrophobicity, as it minimizes the interfacial surface HC-solvent [17].

The changes induced on the surface chemistry of the HCs were also dependent on the preparation conditions, and, as in the case of the previous analyses, two different trends were found, as a result of a less or more aggressive treatment. **Figure 5** collects the spectra obtained for selected HCs; the assignation of bands was made using suitable bibliography.

As inferred from **Figure 4**, the bands found for HCs 1 and 8 are significantly different in size and location to those found for samples 6, 10 and 12.

In the first place, the bands usually assigned to –OH groups (signals around 3400 and 2800 cm−1) are significantly less intense for those samples hydrocarbonized at higher temperature, suggesting that hydrolysis and dehydration were more prominent in these cases.

Also, as the HTC temperature is increased there is a decrease on the oxygenated groups present on the HC surface; for instance, the vanishing of the spectral band at 1030 cm−1 suggests the removal of ether-type functional groups (C–O).

A peak at 1264 cm−1, corresponding to the C–O–C bond of cellulose, is clearly found in samples 1 and 8, and remains, also slighter, for the remaining samples, indicating that part of the cellulose was degraded, but there is still a fraction of it that did not react.

#### *Analytical Pyrolysis*

On the other hand, the bands around 600 cm−1 are also less intense. Likewise, other bands appear or become more intense, such as the one located at 1700 cm−1, suggesting a larger presence of carbonyl groups. Also, the presence of the band at 1600 cm−1 can be associated to a greater aromatization degree (vibration C=C) on the hydrochars.

#### **Figure 4.**

*SEM micrographs of selected HCs: (a) 1 (magnification: 3500; (b) 8 (magnification: 2500); (c) 6 (magnification: 6500); (d) 10 (magnification: 2500); and (e) 12 (magnification: 5000).*

**67**

*Hydrocarbonization. Does It Worth to Be Called a Pretreatment?*

The HTC of cellulose brings out a significant amount on the physical and chemical features of the material, that, depending on the experimental conditions used,

It was found that there is a lower limit in the experimental reaction conditions that has to be attained in order to guarantee that HTC takes place and that, in the case of cellulose, this point is associated to the use of temperatures higher than 200°C. Once these conditions are reached, the prominence of a complex combination of reactions takes place (hydrolysis, dehydration, decarboxylation, decarbonylation, repolymerization, condensation, aromatization…), whose occurrence gives rise to significant changes on the HC chemical composition, morphology, and

Apart from the increase in fixed carbon and decrease in volatile matter and moisture (and, in consequence, enhanced energy densification), the behavior towards pyrolysis and combustion is clearly modified after HTC. In this way, it is confirmed that the fragments resultant from cellulose breaking are combined and a new solid is formed, with lignite-type features, and enhanced resistance to thermal degradation. The release of CO2 during combustion can confirm this effect, since it

Other important features brought up by HTC are related to the different surface morphology, increase in aromaticity, hydrophobicity and development of oxygen surface groups, whose abundancy can also be modeled as a result of the experimen-

These changes justify the use of HTC as sustainable and straightforward method to produce materials suitable for many applications, and also as pretreatment for other processes. The lower moisture is advantageous for improving storage conditions, and also to avoid cost-intensive drying processes prior to combustion processes. Also, the enhanced heating value and hydrophobicity is positive for the use

The greater porosity and stability provide a better behavior towards applications related to soil remediation and adsorption processes. Besides, the availability of π electrons related to greater aromaticity is very interesting if the HC is to be used to

was present upon degradation up to temperatures as high as 700°C.

produce supercapacitors or other energy storage devices.

*DOI: http://dx.doi.org/10.5772/intechopen.79477*

**4. Concluding remarks**

*FT-IR spectra of selected hydrochars.*

**Figure 5.**

surface functional groups.

tal conditions.

of HCs as biofuels.

can be determinant for its further use.

*Hydrocarbonization. Does It Worth to Be Called a Pretreatment? DOI: http://dx.doi.org/10.5772/intechopen.79477*

**Figure 5.** *FT-IR spectra of selected hydrochars.*

*Analytical Pyrolysis*

the hydrochars.

On the other hand, the bands around 600 cm−1 are also less intense. Likewise, other bands appear or become more intense, such as the one located at 1700 cm−1, suggesting a larger presence of carbonyl groups. Also, the presence of the band at 1600 cm−1 can be associated to a greater aromatization degree (vibration C=C) on

**66**

**Figure 4.**

*SEM micrographs of selected HCs: (a) 1 (magnification: 3500; (b) 8 (magnification: 2500); (c) 6 (magnification: 6500); (d) 10 (magnification: 2500); and (e) 12 (magnification: 5000).*

#### **4. Concluding remarks**

The HTC of cellulose brings out a significant amount on the physical and chemical features of the material, that, depending on the experimental conditions used, can be determinant for its further use.

It was found that there is a lower limit in the experimental reaction conditions that has to be attained in order to guarantee that HTC takes place and that, in the case of cellulose, this point is associated to the use of temperatures higher than 200°C. Once these conditions are reached, the prominence of a complex combination of reactions takes place (hydrolysis, dehydration, decarboxylation, decarbonylation, repolymerization, condensation, aromatization…), whose occurrence gives rise to significant changes on the HC chemical composition, morphology, and surface functional groups.

Apart from the increase in fixed carbon and decrease in volatile matter and moisture (and, in consequence, enhanced energy densification), the behavior towards pyrolysis and combustion is clearly modified after HTC. In this way, it is confirmed that the fragments resultant from cellulose breaking are combined and a new solid is formed, with lignite-type features, and enhanced resistance to thermal degradation. The release of CO2 during combustion can confirm this effect, since it was present upon degradation up to temperatures as high as 700°C.

Other important features brought up by HTC are related to the different surface morphology, increase in aromaticity, hydrophobicity and development of oxygen surface groups, whose abundancy can also be modeled as a result of the experimental conditions.

These changes justify the use of HTC as sustainable and straightforward method to produce materials suitable for many applications, and also as pretreatment for other processes. The lower moisture is advantageous for improving storage conditions, and also to avoid cost-intensive drying processes prior to combustion processes. Also, the enhanced heating value and hydrophobicity is positive for the use of HCs as biofuels.

The greater porosity and stability provide a better behavior towards applications related to soil remediation and adsorption processes. Besides, the availability of π electrons related to greater aromaticity is very interesting if the HC is to be used to produce supercapacitors or other energy storage devices.

#### *Analytical Pyrolysis*

Finally, the variety and abundancy of oxygenated functional groups is related to an enhanced reactivity towards activation and improved adsorption performance towards particular adsorbates.

### **Acknowledgements**

This work has received funding from "Junta de Extremadura" through project IB16108, and from "Ministerio de Economía y Competitividad," via project CTM2016-75937-R. Also, the authors thank the Service "SAIUEX" (Servicios de Apoyo a la Investigación de la Universidad de Extremadura) for Surface characterization analyses.

### **Author details**

Silvia Román1 \*, Beatriz Ledesma1 , Andrés Álvarez-Murillo1 , Eduardo Sabio1 , J. F. González1 , Mara Olivares-Marín<sup>2</sup> and Mouzaina Boutieb3

1 Department of Applied Physics, University of Extremadura, Badajoz, Spain

2 Mechanical, Energetic and Materials Engineering Department, University of Extremadura, Badajoz, Spain

3 Laboratory of Process Engineering and Industrial Systems (LR11ES54), National School of Engineering, University of Gabès, Tunisia

\*Address all correspondence to: sroman@unex.es

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**69**

*Hydrocarbonization. Does It Worth to Be Called a Pretreatment?*

[8] Pala M, Kantarli IC, Buyukisik HB, Yanik J. Hydrothermal carbonization and torrefaction of grape pomace: A comparative evaluation. Bioresource Technology. 2014;**161**:255-262

[9] Pham TPT, Kaushik R, Parshetti GK, Mahmood R, Balasubramanian R. Food waste-to-energy conversion technologies: Current status and future directions. Waste Management.

[10] Álvarez-Murillo A, Ledesma B, Román S, Sabio E, Gañán J. Biomass pyrolysis toward hydrocarbonization. Influence on subsequent steam gasification processes. Journal of Analytical and Applied Pyrolysis. 2015;**113**:380-389. DOI: 10.1016/j.

[11] Peterson AA, Vogel F, Lachance RP,

technologies. Energy & Environmental Science. 2008;**1**(1):32-65. DOI: 10.1039/

[12] Bandura A, Lvov A. The ionization constant of water over wide range of temperature and density. Journal of Physical and Chemical Reference Data.

[13] Román S, Nabais JMV, Laginhas C, Ledesma B, González JF. Hydrothermal carbonization as an effective way of densifying the energy content of biomass. Fuel Processing Technology. 2012;**103**:78-83. DOI: 10.1016/j.

[14] Reza MT, Uddin MH, Lynam JG,

Hydrothermal carbonization of loblolly pine: Reaction chemistry and water balance. Biomass Conversion and Biorefinery. 2014;**4**:311-321

Hoekman SK, Coronella CJ.

Fröling M, Antal J, Tester JW. Thermochemical biofuel production in hydrothermal media: A review of sub- and supercritical water

2015;**38**:399-408

jaap. 2015.02.030

B810100K

2006;**35**(1):793-800

fuproc.2011.11.009

[1] Global Trends 2016: Figures at a Glance. The UN Refugees Agency. Available from: http://www.unhcr.org/ figures-at-a-glance.html [Accessed: May

*DOI: http://dx.doi.org/10.5772/intechopen.79477*

[2] Biobased Industries. European Comission Report. Horizon 2020: The EU Framework Programme for Research and Innovation. Available from: https:// ec.europa.eu/programmes/horizon2020/ en/area/bio-based-industries [Accessed:

[3] Román S, Libra J, Berge N, Sabio E, Ro K, Liang L, Ledesma B, Álvarez A, Bae S. Hydrothermal carbonization: Modeling, final properties design and applications: A review.

Energies. 2018;**11**:216. DOI: 10.3390/

[4] Fernandez ME, Ledesma B, Román S, Bonelli PR, Cukierman AL. Development and characterization of activated hydrochars from orange peels as potential adsorbents for emerging organic contaminants.

Bioresource Technology.

[5] Sabio E, Álvarez-Murillo A, Román S, Ledesma B. Conversion of tomato-peel waste into solid fuel by hydrothermal carbonization: Influence of the processing variables. Waste Management.

[6] Álvarez-Murillo A, Sabio E, Ledesma B, Román S, González-García CM. Generation of biofuel from hydrothermal carbonization of cellulose. Kinetics modelling. Energy.

[7] Berge ND, Ro KS, Mao J, Flora JRV, Chappell MA, Bae S. Hydrothermal carbonization of municipal waste streams. Environmental Science and Technology. 2011;**45**(13):5696-5703

2015;**183**:221-228

2016;**47**:122-132

2016;**94**:600-608

2018]

**References**

October 2017]

en11010216

*Hydrocarbonization. Does It Worth to Be Called a Pretreatment? DOI: http://dx.doi.org/10.5772/intechopen.79477*

### **References**

*Analytical Pyrolysis*

towards particular adsorbates.

**Acknowledgements**

ization analyses.

**Author details**

Silvia Román1

J. F. González1

Extremadura, Badajoz, Spain

**68**

provided the original work is properly cited.

\*, Beatriz Ledesma1

, Mara Olivares-Marín<sup>2</sup>

School of Engineering, University of Gabès, Tunisia

\*Address all correspondence to: sroman@unex.es

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

, Andrés Álvarez-Murillo1

Finally, the variety and abundancy of oxygenated functional groups is related to an enhanced reactivity towards activation and improved adsorption performance

This work has received funding from "Junta de Extremadura" through project IB16108, and from "Ministerio de Economía y Competitividad," via project CTM2016-75937-R. Also, the authors thank the Service "SAIUEX" (Servicios de Apoyo a la Investigación de la Universidad de Extremadura) for Surface character-

1 Department of Applied Physics, University of Extremadura, Badajoz, Spain

2 Mechanical, Energetic and Materials Engineering Department, University of

3 Laboratory of Process Engineering and Industrial Systems (LR11ES54), National

and Mouzaina Boutieb3

, Eduardo Sabio1

,

[1] Global Trends 2016: Figures at a Glance. The UN Refugees Agency. Available from: http://www.unhcr.org/ figures-at-a-glance.html [Accessed: May 2018]

[2] Biobased Industries. European Comission Report. Horizon 2020: The EU Framework Programme for Research and Innovation. Available from: https:// ec.europa.eu/programmes/horizon2020/ en/area/bio-based-industries [Accessed: October 2017]

[3] Román S, Libra J, Berge N, Sabio E, Ro K, Liang L, Ledesma B, Álvarez A, Bae S. Hydrothermal carbonization: Modeling, final properties design and applications: A review. Energies. 2018;**11**:216. DOI: 10.3390/ en11010216

[4] Fernandez ME, Ledesma B, Román S, Bonelli PR, Cukierman AL. Development and characterization of activated hydrochars from orange peels as potential adsorbents for emerging organic contaminants. Bioresource Technology. 2015;**183**:221-228

[5] Sabio E, Álvarez-Murillo A, Román S, Ledesma B. Conversion of tomato-peel waste into solid fuel by hydrothermal carbonization: Influence of the processing variables. Waste Management. 2016;**47**:122-132

[6] Álvarez-Murillo A, Sabio E, Ledesma B, Román S, González-García CM. Generation of biofuel from hydrothermal carbonization of cellulose. Kinetics modelling. Energy. 2016;**94**:600-608

[7] Berge ND, Ro KS, Mao J, Flora JRV, Chappell MA, Bae S. Hydrothermal carbonization of municipal waste streams. Environmental Science and Technology. 2011;**45**(13):5696-5703

[8] Pala M, Kantarli IC, Buyukisik HB, Yanik J. Hydrothermal carbonization and torrefaction of grape pomace: A comparative evaluation. Bioresource Technology. 2014;**161**:255-262

[9] Pham TPT, Kaushik R, Parshetti GK, Mahmood R, Balasubramanian R. Food waste-to-energy conversion technologies: Current status and future directions. Waste Management. 2015;**38**:399-408

[10] Álvarez-Murillo A, Ledesma B, Román S, Sabio E, Gañán J. Biomass pyrolysis toward hydrocarbonization. Influence on subsequent steam gasification processes. Journal of Analytical and Applied Pyrolysis. 2015;**113**:380-389. DOI: 10.1016/j. jaap. 2015.02.030

[11] Peterson AA, Vogel F, Lachance RP, Fröling M, Antal J, Tester JW. Thermochemical biofuel production in hydrothermal media: A review of sub- and supercritical water technologies. Energy & Environmental Science. 2008;**1**(1):32-65. DOI: 10.1039/ B810100K

[12] Bandura A, Lvov A. The ionization constant of water over wide range of temperature and density. Journal of Physical and Chemical Reference Data. 2006;**35**(1):793-800

[13] Román S, Nabais JMV, Laginhas C, Ledesma B, González JF. Hydrothermal carbonization as an effective way of densifying the energy content of biomass. Fuel Processing Technology. 2012;**103**:78-83. DOI: 10.1016/j. fuproc.2011.11.009

[14] Reza MT, Uddin MH, Lynam JG, Hoekman SK, Coronella CJ. Hydrothermal carbonization of loblolly pine: Reaction chemistry and water balance. Biomass Conversion and Biorefinery. 2014;**4**:311-321

#### *Analytical Pyrolysis*

[15] Funke A, Ziegler F. Hydrothermal carbonization of biomass: A summary and discussion of chemical mechanisms for process engineering. Biofuels, Bioprodunts Biorefinery. 2010;**4**:160-177

[16] Skodras G, Palladas A, Kaldis SP, Sakellaropoulos GP. Cleaner co-combustion of lignite-biomasswaste blends by utilising inhibiting compounds of toxic emissions. Chemosphere. 2007;**67**:191-197

[17] Falcó C. Sustainable biomassderived hydrothermal carbons for energy applications [doctoral Phd]. Postdam: Max Planck Institut für Kolloid und Grenzflächenforschung; 2012

**71**

**Chapter 5**

**Abstract**

**1. Introduction**

Estimation of Energy Potential for

Solid Pyrolysis By-Products Using

Waste can be converted into energy and value-added products by thermochemical processes. Pyrolysis represents the thermal degradation of the material under a non-oxidant atmosphere leading to generation of three products: char solid, oil—liquid and pyrolysis gas. Pyrolysis process means a complex mechanism of reactions, endothermic and/or exothermic chemical reactions that occurs simultaneously and/or subsequently. The use of lignocellulosic and plastic waste for energy purposes leads to the production of solids that could replace much of the conventional fuels once energy conversion technologies will prove profitable. In this chapter the authors proposed to describe, analyze and apply analytical methods for the heating value estimation of the solid products generated by pyrolysis of different wood and plastic materials. Our results obtained by experimental studies and empirical formulas will be evaluated and compared. The impact of the thermochemical process operational conditions on the variation of chars and biochars

Today, the society concentrates on technological forces to switch the energy generation from conventional sources to renewables. This global tendency evolved due to the use of more clean, alternate and reusable energy sources. Denmark has already produced 44% of its electricity needs with renewable wind power and it intends to require at least 50% of its energy needs to come from renewable sources by 2030 [1]. The Scottish Government aims to generate 100% of Scotland's electrical power from renewable energy by 2020. Also, India plans nearly 60% of electricity capacity from non-fossil fuels by 2027. Waste and biomass are inevitable products of society. The main challenge for the future generations is to investigate how to manage large quantities of these fuels in a sustainable way. The energy content (heating value) represents a key factor of the waste, which determines how much energy can be extracted from it. Wood, cardboard or plastic waste is one of the main components of the municipal solid wastes (MSW), residential types respectively. These energy resources could be exploited by thermal processes to produce solids fuels with valuable energy content. Cellulosic and plastic residues, despite others exhaustible or expensive materials, could be used to produce fuels with valuable energy content.

Analytical Methods

*Gabriela Ionescu and Cora Bulmău*

heating value will be also discussed in this chapter.

**Keywords:** analytical pyrolysis, heating value, biomass, plastic

#### **Chapter 5**

*Analytical Pyrolysis*

[15] Funke A, Ziegler F. Hydrothermal carbonization of biomass: A summary and discussion of chemical mechanisms for process engineering. Biofuels, Bioprodunts Biorefinery. 2010;**4**:160-177

[16] Skodras G, Palladas A, Kaldis SP, Sakellaropoulos GP. Cleaner co-combustion of lignite-biomasswaste blends by utilising inhibiting compounds of toxic emissions. Chemosphere. 2007;**67**:191-197

[17] Falcó C. Sustainable biomassderived hydrothermal carbons for energy applications [doctoral Phd]. Postdam: Max Planck Institut für Kolloid und Grenzflächenforschung;

2012

**70**

## Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods

*Gabriela Ionescu and Cora Bulmău*

#### **Abstract**

Waste can be converted into energy and value-added products by thermochemical processes. Pyrolysis represents the thermal degradation of the material under a non-oxidant atmosphere leading to generation of three products: char solid, oil—liquid and pyrolysis gas. Pyrolysis process means a complex mechanism of reactions, endothermic and/or exothermic chemical reactions that occurs simultaneously and/or subsequently. The use of lignocellulosic and plastic waste for energy purposes leads to the production of solids that could replace much of the conventional fuels once energy conversion technologies will prove profitable. In this chapter the authors proposed to describe, analyze and apply analytical methods for the heating value estimation of the solid products generated by pyrolysis of different wood and plastic materials. Our results obtained by experimental studies and empirical formulas will be evaluated and compared. The impact of the thermochemical process operational conditions on the variation of chars and biochars heating value will be also discussed in this chapter.

**Keywords:** analytical pyrolysis, heating value, biomass, plastic

#### **1. Introduction**

Today, the society concentrates on technological forces to switch the energy generation from conventional sources to renewables. This global tendency evolved due to the use of more clean, alternate and reusable energy sources. Denmark has already produced 44% of its electricity needs with renewable wind power and it intends to require at least 50% of its energy needs to come from renewable sources by 2030 [1]. The Scottish Government aims to generate 100% of Scotland's electrical power from renewable energy by 2020. Also, India plans nearly 60% of electricity capacity from non-fossil fuels by 2027. Waste and biomass are inevitable products of society. The main challenge for the future generations is to investigate how to manage large quantities of these fuels in a sustainable way. The energy content (heating value) represents a key factor of the waste, which determines how much energy can be extracted from it. Wood, cardboard or plastic waste is one of the main components of the municipal solid wastes (MSW), residential types respectively. These energy resources could be exploited by thermal processes to produce solids fuels with valuable energy content. Cellulosic and plastic residues, despite others exhaustible or expensive materials, could be used to produce fuels with valuable energy content.

The impact of biomass properties and operational conditions of pyrolysis processes on physical and chemical properties of the biochar has been already discussed [2–4], but insufficient materials are published concerning the relation between biomass and plastic based waste types and the energy content of chars and biochars. The present work brings contributions with critical analytical data regarding this correlation. This could help to identify optimum types of waste to be treated to produce chars valuable for their energy potential in a variety of pyrolysis units. Therefore, the research concentrates on theoretical and experimental studies that could give more clues about the heating value of the chars generated from five types of waste. So, we proposed to obtain viable experimental results applicative at industrial level and give some ideas how use the chars obtained or how to replace some materials with these lignocellulosic/plastic wastes. These could solve environmental problems that affect in the present the entire world.

#### **2. Calorimetry: instrumentation and analysis**

Calorimetry is the science dedicated to the measuring of heat. This represents the amount of energy exchanged within a given time interval in the form of a heat flow [5]. Since its foundation in 1780, the calorimetry meets variated and successful uses in many fields. The modern calorimetry has some targeted fields: material science, life science (biology, medicine and biochemistry), pharmacy and food science, environmental control analysis, safety investigations and determinations of energy content of fuels, search of new alternative energy sources.

During the past century, the classical methods of calorimetry have not known many changes, only microelectronic and computer science get progress allowing to develop new types of calorimeters and open new fields of application.

Each calorimetric experiment has three stages very well defined:


#### **2.1 Units**

Heat cannot be measured by a direct method. Consequently, heat must be determined by means of its effects. The oldest unit quantity of heat is the calorie. This was defined in terms of the heating of water. A traditional definition specifies that 1 calorie is the amount of heat required to raise the temperature of 1 gram of water by 1°C, from 14.5 to 15.5°C (American Physical Society). Conversion relation between calorie and joule:

1 cal = 4.184 J

1 J = 0.2388459 cal

**73**

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods*

The last unit is the International Table (IT) calorie that has been adopted in the publications of the Energy Information Administration of the U.S. Department of Energy (DOE/EIA) [7] and of the International Energy Agency of the Organization

The calorimeter represents an instrument used in calorimetric testing (calorimetry) that allows to measure the amount of heat released or absorbed in chemical or physical reactions. It can determine heat content, latent heat, specific heat, and other thermal properties of substances. The design of a calorimeter is based on a container with a temperature thermocouple through which the thermal phenomenon is investigated. The container communicates with the environment by its

There are many types of calorimeters used for measurement of the heat. The

• *Bomb calorimeters*—they are isolated devices with a constant volume. Since the volume does not changed, the instruments measure the heat evolved under con-

qv = C × dT [J], (1)

dE = qv = C × dT [J] (2)

analysis. If a calorimeter measures the heat into or out of a sample, a differential calorimeter measures the heat of sample relative to a reference. The difference in the quantity of heat necessary to increase the temperature of the sample starting from the reference temperature is measured as a function of temperature. In the last years, the methods of thermal analysis have been widely accepted in analytical chemistry. Differential scanning calorimeters are often used in many industries—from pharmaceuticals and polymers, to nanomaterials and food products.

• Isothermal titration calorimeters—they are based on a technique (isothermal titration calorimetry—ITC) used in quantitative studies of an extensive variety of biomolecular interactions. They directly measure the heat that is either released or absorbed during a biomolecular binding event. Isothermal titration calorimetry (ITC) is a valid method to investigate biological reactions with

• *Calvet-type calorimeters*—they are not so often used. They can measure the enthalpy change during sublimation reactions and the behavior of a material. In case of these calorimeters, the detection is based on a three-dimensional flux meter sensor. There is no calibration and standard methods required for this type of calorimeters. The calibration can be achieved at a constant temperature, in heating and cooling modes, while the system can manage temperatures up to 1600°C. Calvet microcalorimeter is one of the most known type of

high sensitivity and accuracy at a constant temperature [9].

• *Differential scanning calorimeters*—represent an important tool in thermal

where dT is the temperature increase. The qv so measured is also called the

*DOI: http://dx.doi.org/10.5772/intechopen.80861*

**2.2 Calorimeters**

most common are:

stant volume, qv,

change in internal energy, dE. Note that.

1 Btu = 251.9958 cal

insulating walls that have some thermal resistance.

for Economic Co-operation and Development (OECD/IEA) [8].

Nowadays, the International System of Unit recommend joule as unit for heat. Another common unit for heat is British thermal unit (Btu), that is the English system analog of the calorie.

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods DOI: http://dx.doi.org/10.5772/intechopen.80861*

1 Btu = 251.9958 cal

The last unit is the International Table (IT) calorie that has been adopted in the publications of the Energy Information Administration of the U.S. Department of Energy (DOE/EIA) [7] and of the International Energy Agency of the Organization for Economic Co-operation and Development (OECD/IEA) [8].

#### **2.2 Calorimeters**

*Analytical Pyrolysis*

The impact of biomass properties and operational conditions of pyrolysis processes on physical and chemical properties of the biochar has been already discussed [2–4], but insufficient materials are published concerning the relation between biomass and plastic based waste types and the energy content of chars and biochars. The present work brings contributions with critical analytical data regarding this correlation. This could help to identify optimum types of waste to be treated to produce chars valuable for their energy potential in a variety of pyrolysis units. Therefore, the research concentrates on theoretical and experimental studies that could give more clues about the heating value of the chars generated from five types of waste. So, we proposed to obtain viable experimental results applicative at industrial level and give some ideas how use the chars obtained or how to replace some materials with these lignocellulosic/plastic wastes. These could solve environ-

Calorimetry is the science dedicated to the measuring of heat. This represents the amount of energy exchanged within a given time interval in the form of a heat flow [5]. Since its foundation in 1780, the calorimetry meets variated and successful uses in many fields. The modern calorimetry has some targeted fields: material science, life science (biology, medicine and biochemistry), pharmacy and food science, environmental control analysis, safety investigations and determinations of

During the past century, the classical methods of calorimetry have not known many changes, only microelectronic and computer science get progress allowing to

• The calorimetric part assumes the accurate determination of the energy gener-

• The chemical part involves the characterization of the initial and final states.

• The transformation of the results obtained in the calorimetric experiment to a standard-state combustion energy at 298.15 K, from which a standard enthalpy

Heat cannot be measured by a direct method. Consequently, heat must be determined by means of its effects. The oldest unit quantity of heat is the calorie. This was defined in terms of the heating of water. A traditional definition specifies that 1 calorie is the amount of heat required to raise the temperature of 1 gram of water by 1°C, from 14.5 to 15.5°C (American Physical Society). Conversion relation

Nowadays, the International System of Unit recommend joule as unit for heat. Another common unit for heat is British thermal unit (Btu), that is the English

mental problems that affect in the present the entire world.

energy content of fuels, search of new alternative energy sources.

develop new types of calorimeters and open new fields of application. Each calorimetric experiment has three stages very well defined:

**2. Calorimetry: instrumentation and analysis**

ated in the reaction.

between calorie and joule:

system analog of the calorie.

of formation can be calculated [6].

1 cal = 4.184 J

1 J = 0.2388459 cal

**72**

**2.1 Units**

The calorimeter represents an instrument used in calorimetric testing (calorimetry) that allows to measure the amount of heat released or absorbed in chemical or physical reactions. It can determine heat content, latent heat, specific heat, and other thermal properties of substances. The design of a calorimeter is based on a container with a temperature thermocouple through which the thermal phenomenon is investigated. The container communicates with the environment by its insulating walls that have some thermal resistance.

There are many types of calorimeters used for measurement of the heat. The most common are:

• *Bomb calorimeters*—they are isolated devices with a constant volume. Since the volume does not changed, the instruments measure the heat evolved under constant volume, qv,

$$\mathbf{q}\_{\mathbf{v}} = \mathbf{C} \times \mathbf{d}T \, \{\mathbf{j}\},\tag{1}$$

where dT is the temperature increase. The qv so measured is also called the change in internal energy, dE. Note that.

$$\mathbf{dE} = \mathbf{q}\_{\mathbf{v}} = \mathbf{C} \times \mathbf{d}T \text{ [J]} \tag{2}$$


heat conduction calorimeter [10], SETARAM Instrumentation being the only producer of these categories instruments.

During this chapter we focused on oxygen bomb calorimeters. These type of calorimeters have a wide range of uses, but their mainly applicability are in the coal industry, i.e., coal fired power stations, iron and steel plants, cement plants and other users of coal. Also, they are often used in other non-coal related industries. Some examples for this case are:


Other important applicability of the bomb calorimeters is the use in colleges, universities or research institutes, where these instruments could bring a contribution to teaching or to experimental and development research that is performed in many departments. But the main applications for oxygen bomb calorimeters are:


### **3. High heating value**

The heating value or calorific value defines the energy content of a fuel. It is one of the most important properties to evaluate the fuel quality and a key parameter in the development of any energetic application. The heating value is the amount of heat released during the complete combustion of a specific fuel quantity at standard conditions, pressure 1 atm and temperature 25°C. Generally, it is measured in energy content (Joule, Calorie, British Thermal Unit- Btu or Watt-hours-Wh) per specific quantity (mass or volume) of the combusted fuel. The specific quantity is given by the fuel physical state: molar, gram or kilogram for solid fuels, liter for liquid fuels and cubic meter for gaseous fuels.

The fuel heating value can be classified as Higher or Lower Heating Value (LHV). The High Heating Value (HHV) otherwise known as heat of combustion or Higher Calorific Value or Gross Calorific Value (GCV) or Gross Energy or Upper Heating Value is the total amount of energy released during the fuel complete combustion per fuel specific quantity. The LHV, also known as Net

**75**

waste.

[25, 26].

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods*

Heating Value or Net Calorific Value, is determined by subtracting the latent heat of vaporization produced during the complete combustion of the fuel from the

The heating value can be estimated theoretically based on the proximate, ultimate and chemical analysis composition of the fuel by using dedicated empirical formulas or experimentally by employing an adiabatic calorimetric bomb, which

Although the calorimeter instrument is easy to use and relatively accurate, it might not always be accessible to researchers. The earliest and most used empirical correlation for the HHV estimation was developed by Dulong by in end of nineteenth century, based on the ultimate analysis of coal [15]. One century later, Tillman [16] developed the simplest heating value prediction formula for woody

Up to now, various empirical formulas, models and correlations have been improved or developed for the predication of the HHV using the proximate or ultimate analysis of the fuel such as: fossil fuels/waste [17], biomass [18, 19], refused derived-fuels [20], commingled wastes [21, 22]. However, sometimes the models can have their limitations, due to their wide variety on fuels applications, that can be homogeneous (e.g., fossil fuels and biomass) or heterogenous (refused derived

• the equations based on the elemental analysis are generally more accurate than

• usually, the weight of the moisture or ash free basis or both, is undefined in the

• for precise values, even for homogenous wastes, like biomass, Özyuğuran and Yaman, show the necessity to create models for each subclasses (e.g., herba-

• sometimes the same model can be reproduced based on different units (i.e.,

• some studies suggest the creation of personalized models, based on the fuel derivation/application, country/region, to avoid the over or under prediction

**3.2 Estimation of the high heating value from ultimate or proximate analysis**

In the absence of calorimeter instrument, the HHV can be estimated based on

Based on a comprehensive literature review the most common equations for the appropriate estimation of the HHV of biomass, commingled biomass-plastic waste, municipal solid waste (MSW), coal and char are summarized in **Table 1**. Ten correlations for each type of analysis (ultimate and proximate) were studied in order to establish the wide applicability and versatility of the formulas by considering cellulose, hemicellulose, lignocellulose and plastic polymers-based

measures the enthalpy change between reactants and products [12–14].

*DOI: http://dx.doi.org/10.5772/intechopen.80861*

**3.1 Theoretical estimation of the heating value**

biomass based on the fuel carbon content.

fuels, solid recovered fuels, municipal solid waste) such as:

those based on proximate analysis [12];

ceous, woody or agricultural waste) [23];

kcal/kg, kJ/kg, Btu/lb, etc.) leading to confusion [24].

the elemental, proximate or physical analysis of the fuel.

equation, limiting its accuracy;

HHV [11].

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods DOI: http://dx.doi.org/10.5772/intechopen.80861*

Heating Value or Net Calorific Value, is determined by subtracting the latent heat of vaporization produced during the complete combustion of the fuel from the HHV [11].

The heating value can be estimated theoretically based on the proximate, ultimate and chemical analysis composition of the fuel by using dedicated empirical formulas or experimentally by employing an adiabatic calorimetric bomb, which measures the enthalpy change between reactants and products [12–14].

#### **3.1 Theoretical estimation of the heating value**

*Analytical Pyrolysis*

value,

heat conduction calorimeter [10], SETARAM Instrumentation being the only

• animal digestion of feeds, dairy products and other foods to measure the caloric

Other important applicability of the bomb calorimeters is the use in colleges, universities or research institutes, where these instruments could bring a contribution to teaching or to experimental and development research that is performed in many departments. But the main applications for oxygen bomb calorimeters are:

The heating value or calorific value defines the energy content of a fuel. It is one of the most important properties to evaluate the fuel quality and a key parameter in the development of any energetic application. The heating value is the amount of heat released during the complete combustion of a specific fuel quantity at standard conditions, pressure 1 atm and temperature 25°C. Generally, it is measured in energy content (Joule, Calorie, British Thermal Unit- Btu or Watt-hours-Wh) per specific quantity (mass or volume) of the combusted fuel. The specific quantity is given by the fuel physical state: molar, gram or kilogram for solid fuels, liter for

The fuel heating value can be classified as Higher or Lower Heating Value (LHV). The High Heating Value (HHV) otherwise known as heat of combustion or Higher Calorific Value or Gross Calorific Value (GCV) or Gross Energy or Upper Heating Value is the total amount of energy released during the fuel complete combustion per fuel specific quantity. The LHV, also known as Net

During this chapter we focused on oxygen bomb calorimeters. These type of calorimeters have a wide range of uses, but their mainly applicability are in the coal industry, i.e., coal fired power stations, iron and steel plants, cement plants and other users of coal. Also, they are often used in other non-coal related industries.

producer of these categories instruments.

• animal feeds—to determine their nutritional value,

• ammunition propellants are analyzed for their effectiveness,

• liquid fuels can also be analyzed in a similar way to coal.

Some examples for this case are:

• Solid and liquid fuel testing,

• Waste and refuse disposal,

• Food and metabolic studies,

• Educational training.

**3. High heating value**

• Propellant and explosive testing,

• Fundamental thermodynamic studies,

liquid fuels and cubic meter for gaseous fuels.

**74**

Although the calorimeter instrument is easy to use and relatively accurate, it might not always be accessible to researchers. The earliest and most used empirical correlation for the HHV estimation was developed by Dulong by in end of nineteenth century, based on the ultimate analysis of coal [15]. One century later, Tillman [16] developed the simplest heating value prediction formula for woody biomass based on the fuel carbon content.

Up to now, various empirical formulas, models and correlations have been improved or developed for the predication of the HHV using the proximate or ultimate analysis of the fuel such as: fossil fuels/waste [17], biomass [18, 19], refused derived-fuels [20], commingled wastes [21, 22]. However, sometimes the models can have their limitations, due to their wide variety on fuels applications, that can be homogeneous (e.g., fossil fuels and biomass) or heterogenous (refused derived fuels, solid recovered fuels, municipal solid waste) such as:


#### **3.2 Estimation of the high heating value from ultimate or proximate analysis**

In the absence of calorimeter instrument, the HHV can be estimated based on the elemental, proximate or physical analysis of the fuel.

Based on a comprehensive literature review the most common equations for the appropriate estimation of the HHV of biomass, commingled biomass-plastic waste, municipal solid waste (MSW), coal and char are summarized in **Table 1**. Ten correlations for each type of analysis (ultimate and proximate) were studied in order to establish the wide applicability and versatility of the formulas by considering cellulose, hemicellulose, lignocellulose and plastic polymers-based waste.


**Table 1.**

**77**

**Table 2.**

*Sample*

Cherry wood waste

**C**

**H**

*Summaries of ultimate and proximate analysis [39, 43].*

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods*

As seen from **Table 1**, most empirical formulas are linear regression models, build based on the mass fractions (weight) or percent of the fuel principal elements and constant coefficients. The simplest equations for the HHV prediction from the ultimate or proximate analysis consider only the carbon (C) fuel content (Eqs. (1, 2)), or ash (A) (Eq. (11)), respectively. Besides these two elements, the reliability of the results increases with the augmentation of the chemical or physical elements used partly or fully in the formulas: hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), chlorine (Cl) or fixed carbon (FC), volatile matter (VM) and moisture (W). Over more Eqs. (2, 5, 8, 16) represent one of the most known and used equations in the exact science area, while the rest have been proposed, adjusted or improved in

It is worth noting in order to use or create dedicated empirical formulas, the experimental determination of the chemical–physical characteristic of the fuel is need. In this case dedicated laboratory instruments are necessary. The proximate analysis could be established by using a thermogravimetric analyzer (TG), follow

ing the ASTM D7582-12. In the absence of the TG analyzer, the drying oven and the calcination furnace can be used. Thus, for woody-biomass the content of moisture is determined according to ASTM standard method 871-82, for volatile matter (VM) with ASTM D5832-98 (2014) and ash with ASTM D1102-84 (2013). The fixed carbon content (FC) is always determined by difference considering the sum of total moisture (if available), volatile matter and ash. The elementar analyzer is used for the ultimate analysis determination adopting ASTM D5373 – 08. Usually the oxygen (O) is obtained by subtracting the rest of the determined chemical elements carbon (C), hydrogen (H), nitrogen (N), sulfur (S) and chlorine (Cl) from the total

− Ash).

The validation of the HHV predication models presented in the preceding sec

tion was made by using the characterization of three biomass-based waste (cherry wood, cardboard and newspaper waste) and two types of plastic waste, polypropyl

ene (PP) and high-density polyethylene (HDPE) waste. The waste sampling, along with the analytical and empirical procedure for the ultimate and proximate analysis of the newspaper, cardboard, PP and HDPE resulted from the selective collection of the municipal solid waste were former presented in previews researches made by the authors [39, 40]. The cherry wood waste elemental and proximate composition was obtained after a generic review of the former literature [41, 42]. The summaries

**Ultimate analysis [wt%] Proximate analysis [wt%]**

49.52 5.81 0.31 0.02 44.34 100.00 84.9 15 0.1 100.00

Newspaper 47.00 7.00 2.00 1.00 43.00 100.00 88.4 3.5 8.1 100.00 Cardboard 48.00 8.00 2.00 1.00 41.00 100.00 87.5 6.6 5.9 100.00

PP 85.50 12.50 1.20 0.10 0.70 100.00 99.13 0.27 0.6 100.00 HDPE 84.70 14.47 0.11 0.12 0.60 100.00 99.74 0.06 0.2 100.00

**3.3 Proximate and ultimate analyses data on biomass and plastic waste**

of the ultimate and proximate analysis are presented in **Table 2**

**N**

**S**

− Cl) or by subtracting the carbon (C), hydrogen

.

**O Total V.M. F.C. Ash Total**




*DOI: http://dx.doi.org/10.5772/intechopen.80861*

the last in several decades [15, 19].

− C − H − N − S

(H) and ash from the matter (O = C – H

content (O = 100

*Most common equations used for high heating value prediction.*

#### *Analytical Pyrolysis*

#### *Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods DOI: http://dx.doi.org/10.5772/intechopen.80861*

As seen from **Table 1**, most empirical formulas are linear regression models, build based on the mass fractions (weight) or percent of the fuel principal elements and constant coefficients. The simplest equations for the HHV prediction from the ultimate or proximate analysis consider only the carbon (C) fuel content (Eqs. (1, 2)), or ash (A) (Eq. (11)), respectively. Besides these two elements, the reliability of the results increases with the augmentation of the chemical or physical elements used partly or fully in the formulas: hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), chlorine (Cl) or fixed carbon (FC), volatile matter (VM) and moisture (W). Over more Eqs. (2, 5, 8, 16) represent one of the most known and used equations in the exact science area, while the rest have been proposed, adjusted or improved in the last in several decades [15, 19].

It is worth noting in order to use or create dedicated empirical formulas, the experimental determination of the chemical–physical characteristic of the fuel is need. In this case dedicated laboratory instruments are necessary. The proximate analysis could be established by using a thermogravimetric analyzer (TG), following the ASTM D7582-12. In the absence of the TG analyzer, the drying oven and the calcination furnace can be used. Thus, for woody-biomass the content of moisture is determined according to ASTM standard method 871-82, for volatile matter (VM) with ASTM D5832-98 (2014) and ash with ASTM D1102-84 (2013). The fixed carbon content (FC) is always determined by difference considering the sum of total moisture (if available), volatile matter and ash. The elementar analyzer is used for the ultimate analysis determination adopting ASTM D5373 – 08. Usually the oxygen (O) is obtained by subtracting the rest of the determined chemical elements carbon (C), hydrogen (H), nitrogen (N), sulfur (S) and chlorine (Cl) from the total content (O = 100 − C − H − N − S − Cl) or by subtracting the carbon (C), hydrogen (H) and ash from the matter (O = C – H − Ash).

#### **3.3 Proximate and ultimate analyses data on biomass and plastic waste**

The validation of the HHV predication models presented in the preceding section was made by using the characterization of three biomass-based waste (cherry wood, cardboard and newspaper waste) and two types of plastic waste, polypropylene (PP) and high-density polyethylene (HDPE) waste. The waste sampling, along with the analytical and empirical procedure for the ultimate and proximate analysis of the newspaper, cardboard, PP and HDPE resulted from the selective collection of the municipal solid waste were former presented in previews researches made by the authors [39, 40]. The cherry wood waste elemental and proximate composition was obtained after a generic review of the former literature [41, 42]. The summaries of the ultimate and proximate analysis are presented in **Table 2**.


#### **Table 2.**

*Summaries of ultimate and proximate analysis [39, 43].*

*Analytical Pyrolysis*

[12]

[27]

[21]

[28]

[29]

[30]

[31]

[32]

[21]

[25]

**76**

**Eq no.**

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 *FC, wt% of fixed carbon.*

**Table 1.**

*Most common equations used for high heating value prediction.*

**Name of the author/source**

**Estimation of the high heating value from ultimate analysis**

Sheng and Azevedo

Tillman REM model

Friedl et al.

Dulong

Yacio Dermirbas

Dulong

Boie Scheurer-Kestner

**Estimation of the high heating value from proximate analysis**

García et al.

Yin Cordero et al.,

Phichai et al.

Bento Kathiravale et al

Soponpongpipat et al.

Özyuğuran, et al.

Kieseleret al. Parikh et al.

HHV = 3.55C2

**Original equation**

HHV = 0.3259C + 3.4597

HHV = 0.4373C − 1.6701

HHV = 36C + 120H − 16O

− 232C − 2230H + 51.2C × H + 131N + 20,600

HHV = 7831C + 35,932H − O/8 + 1187O + 578N

HHV = 0.336C + 1.418H − 0.0145O + 0.0941S

HHV = 0.335C + 1.423H − 0.154 \* O − 0.145N

HHV = 144.5C + 609.6H − 76.2O + 40S + 10N

HHV = 35.2C + 116.2H + 6.3N + 10.5S + 11.1O

HHV = 81(C − 3O/4) + 342.5H + 22.5S + 171O/4 − 6(9H + W)

HHV = 18,300 − 3.98A2

HHV = 0.1905VM + 0.2521FC

HHV = 354.3FC + 170.8VM

HHV = 157.34(VM + FC) + 4243.97

HHV = 44.75VM − 5.85W + 21.2

HHV = 356.047VM − 118.035FC − 5600.613

HHV = 35.4879 − 0.3023A − 0.1905VM

HHV = 167.2 − 1.449VM − 1.562FC − 1.846A

HHV = 0.4108FC + 0.1934VM − 0.0211A

HHV = 0.3536FC + 0.1559VM − 0.0078A

*HHV, high heating value; U.M., unit measure; C,H,N,S,O, wt% of carbon, hydrogen, nitrogen, sulphur, oxygen content; W, wt% total moisture content; A, wt% of ash, dry basis; VM, wt% volatile matter;* 

− 112.10A

kJ/kg MJ/kg

kJ/kg kJ/kg kcal/kg

kJ/kg MJ/kg MJ/kg MJ/kg MJ/kg

Biomass Biomass Biomass Biomass Refuse/char

MSW Chars/coal

Biomass

Chars Biomass

[32]

[19]

[33]

[34]

[25]

[35]

[36]

[23]

[37]

[38]

kcal/kg

MJ/kg

J/kg MJ/kg

kJ/kg kcal/kg MJ/kg

J/kg Btu/lb MJ/kg

Biomass Biomass Biomass-plastic

Biomass

Waste Coal/refuse Waste/biomass

Waste/coal Waste/biomass

Waste

**U.M.**

**Recommend fuel type**

**Ref.**

#### **4. Experimental determinations**

The experimental research was developed adopting a bench scale pyrolysis system and an oxygen bomb calorimeter with the purpose to investigate alternative energy sources from residue material as light packaging waste and wooden biomass.

Calorimetry experiments were performed for the solid products (chars) generated by biomass and light packaging waste (LPW) pyrolysis processes and with a calorimetric bomb IKA C200. Testing were completed for five types of chars resulted from waste pyrolysis: biochars produced from woody biomass and mixers of biomass and plastic based material.

#### **4.1 Collection and preparation of the samples**

Five types of materials were considered and analyzed in the present chapter. Cherry sawdust was the wooden biomass used to produce biochar samples and it was collected from furniture industry. The configuration, the procedure to get the reduced dimensions and characterization of the cherry wood and the others plastic based materials were previously detailed described in other works [43, 44]. Other four LPW mixtures representative for Eastern Europe, coming from the MSW selective collection were used: Mix 1 (paper and cardboard mixture—in equal proportion), Mix 2 (plastic solid waste mixture—HDPE, PP, PET—in equal proportion), Mix 3 (90% paper & cardboard waste mixture and 10% plastic solid waste mixture), Mix 4 (67% paper & cardboard waste and 33% plastic solid waste).

Pyrolysis processing was applied to cherry wood, resulting in a series of 12 samples of cherry biochars, 36 samples of LPW mixtures respectively. So, a total of 48 samples were prepared for measurements of high heating values by using the oxygen bomb calorimeter.

#### **4.2 Processing for char samples production**

To obtain the solid pyrolysis by-products that can be used as fuel with high calorific energy content, pyrolysis processes were completed through a laboratory scale pyrolyser. **Figure 1** explains the general schema of the reactor. The furnace temperature was very well controlled to achieve the desired heating rate and temperature for samples thermal-chemical treatment as the furnace is equipped with an automatic integrated control for heating. The tubular batch reactor worked in a discontinuous mode, so the waste sample was placed in a crucible of refractory steel W4541 with tubular parallelepiped form and then this was introduced in the furnace. Each sample of the cherry biomass was weighted trying to keep the mass constant at 25 g. The total amount of the mixture that entered in the crucible was in a range 25–30 g depending on the form and structure of the waste fractions.

**79**

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods*

The reactor was heated by electrical resistances until the temperature of the process has reached the desired value. At this moment the biomass waste sample was introduced in the reactor, where an inert atmosphere was maintained throughout the pyrolysis processing by inserting a nitrogen flow of about 1 l/min. For the types of the materials analyzed in this chapter, the pyrolysis processing was conducted in almost the same conditions: temperature: 400, 500 and 600°C, atmospheric pressure, inert gas: purified N2 (99.9995%) at a gas pressure 50–100 kPa; only the process time was different: 30 min for cherry wood and 60 min for municipal solid waste types. Considering previously results of our experimental research [45] that demonstrated heating value is not very much influenced by the treatment time during the pyrolysis processes but depends more on the process temperature [46], it is valuable to discuss and compare here the actual experimental results. All pyrolysis

Experimental determinations of the high heating value in case of the five types of pyrolysis chars were performed in the laboratory conditions: combustion of the sample under specific conditions in a C200 system according to ASTM D2015-96 standard (1998). C200 (**Figure 2**) can be used to determine the calorific value for solids or liquids samples by engagement an adiabatic bomb calorimeter that allows

The measuring of the samples calorific power involves the following steps:

a. Melting the crucible and weighing the sample using a high precision elec-

c. Positioning the filament (a cotton yarn). It binds in the middle of the firing wire.

f. Transporting the bomb to the oxygen station. Insert oxygen for about 3 min-

d. Place the crucible on the support and insert the filament into the crucible,

*DOI: http://dx.doi.org/10.5772/intechopen.80861*

experiments were done in triplicates.

**Figure 2.**

*Calorimetric system.*

**4.3 Procedure for HHV measurement**

tronic balance;

e. Turning of the bomb;

to measure the heat of reactions involving gases.

b. Inserting the sample into a small plastic bag;

over which the material sample is placed;

utes into the bomb at a pressure of 30 bar.

**Figure 1.** *Simplified scheme of the pyrolysis batch reactor.*

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods DOI: http://dx.doi.org/10.5772/intechopen.80861*

**Figure 2.** *Calorimetric system.*

*Analytical Pyrolysis*

**4. Experimental determinations**

of biomass and plastic based material.

oxygen bomb calorimeter.

**4.2 Processing for char samples production**

**4.1 Collection and preparation of the samples**

The experimental research was developed adopting a bench scale pyrolysis system and an oxygen bomb calorimeter with the purpose to investigate alternative energy sources from residue material as light packaging waste and wooden biomass. Calorimetry experiments were performed for the solid products (chars) generated by biomass and light packaging waste (LPW) pyrolysis processes and with a calorimetric bomb IKA C200. Testing were completed for five types of chars resulted from waste pyrolysis: biochars produced from woody biomass and mixers

Five types of materials were considered and analyzed in the present chapter. Cherry sawdust was the wooden biomass used to produce biochar samples and it was collected from furniture industry. The configuration, the procedure to get the reduced dimensions and characterization of the cherry wood and the others plastic based materials were previously detailed described in other works [43, 44]. Other four LPW mixtures representative for Eastern Europe, coming from the MSW selective collection were used: Mix 1 (paper and cardboard mixture—in equal proportion), Mix 2 (plastic solid waste mixture—HDPE, PP, PET—in equal proportion), Mix 3 (90% paper & cardboard waste mixture and 10% plastic solid waste mixture), Mix 4 (67% paper & cardboard waste and 33% plastic solid waste). Pyrolysis processing was applied to cherry wood, resulting in a series of 12 samples of cherry biochars, 36 samples of LPW mixtures respectively. So, a total of 48 samples were prepared for measurements of high heating values by using the

To obtain the solid pyrolysis by-products that can be used as fuel with high calorific energy content, pyrolysis processes were completed through a laboratory scale pyrolyser. **Figure 1** explains the general schema of the reactor. The furnace temperature was very well controlled to achieve the desired heating rate and temperature for samples thermal-chemical treatment as the furnace is equipped with an automatic integrated control for heating. The tubular batch reactor worked in a discontinuous mode, so the waste sample was placed in a crucible of refractory steel W4541 with tubular parallelepiped form and then this was introduced in the furnace. Each sample of the cherry biomass was weighted trying to keep the mass constant at 25 g. The total amount of the mixture that entered in the crucible was in

a range 25–30 g depending on the form and structure of the waste fractions.

**78**

**Figure 1.**

*Simplified scheme of the pyrolysis batch reactor.*

The reactor was heated by electrical resistances until the temperature of the process has reached the desired value. At this moment the biomass waste sample was introduced in the reactor, where an inert atmosphere was maintained throughout the pyrolysis processing by inserting a nitrogen flow of about 1 l/min. For the types of the materials analyzed in this chapter, the pyrolysis processing was conducted in almost the same conditions: temperature: 400, 500 and 600°C, atmospheric pressure, inert gas: purified N2 (99.9995%) at a gas pressure 50–100 kPa; only the process time was different: 30 min for cherry wood and 60 min for municipal solid waste types. Considering previously results of our experimental research [45] that demonstrated heating value is not very much influenced by the treatment time during the pyrolysis processes but depends more on the process temperature [46], it is valuable to discuss and compare here the actual experimental results. All pyrolysis experiments were done in triplicates.

#### **4.3 Procedure for HHV measurement**

Experimental determinations of the high heating value in case of the five types of pyrolysis chars were performed in the laboratory conditions: combustion of the sample under specific conditions in a C200 system according to ASTM D2015-96 standard (1998). C200 (**Figure 2**) can be used to determine the calorific value for solids or liquids samples by engagement an adiabatic bomb calorimeter that allows to measure the heat of reactions involving gases.

The measuring of the samples calorific power involves the following steps:


All the calorimetric measurements for the determination of biochars and chars HHV were performed in triplicates.

#### **4.4 Results, comparison, and discussions**

#### *4.4.1 Theoretical high heating value of pyrolysis chars*

The HHVs of the biomass and polymer-based materials were predicted by using 20 equations presented in **Table 1**. The ultimate and proximate analysis for each type of material, presented in **Table 2** were used for the application of the formulas. **Table 3** shows the newspaper, cardboard, cherry wood, PP and HDPE waste HHVpredicted values obtained using the equations presented in **Table 1**. To avoid confusion and compare more easily the results, all the predicted values were normalized, by using the same reference unit measure [kJ/kg]. The comparison of the data was made based on: the HHV predicted mean value generated by the equations, standard deviation (STD) by analyzing all the equations from each type of determination (ultimate or proximate analysis), HHV of the material obtained with the calorimeter (HHV experimental) and STD by comparing the predicted and experimental results.

From the elemental analysis models, the HHVs predicted from biomass-based materials (newspaper, cardboard and cherry wood) varies between 21,273 and 23,034 kJ/kg, while the plastic-waste ranges between 44,111–46,017 kJ/kg with a STD of ≈6000–7000 kJ/kg. By comparing only, the data obtained using the equations, the trend lines plotted in **Figure 3** report homogenies correlation between the results for most equations. However there are some visible exceptions since for plastic based materials Eq. (3, 4) underestimate the predicted HHV with almost 30%, while Eq. (7) for plastic and Eqs. (7, 8, 11) for biomass-based waste overestimates it. For some correlations inconsistent results can be observed while comparing the mean HHV predicted v.s. HHV experimental. For a better evaluation of the correlation the mean absolute error (MAE) was determined. The MAE evaluates the accuracy of the HHV predicted to the experimental one. In this case, lower values tending to 0% indicate good accuracy of a specific correlation. The MAE negative values indicate the underestimation of the results, while the positive their

**81**

**High heating value (HHV) [kJ/kg]**

**Eq. no.** **Type of waste/**

**name of the author/s**

Newspaper Cardboard Cherry wood

19,598

19,985

17,653

19,632

27,116

24,201

17,984

16,975

29,102

20,486

21,273

3926

17,500

1887

waste

PP HDPE **Eq. no.** **Type of waste/**

**García** 

**Yin**

**Cordero** 

**Phichai** 

**Bento**

**Kathiravale** 

**Soponpongpipat** 

**Özyuğuran,** 

**Kieseler** 

**Parikh** 

**HHV** 

**STD all** 

**HHV** 

**STD** 

**(Predicted v.s.** 

**experimental)**

**predicted** 

**eq.**

**experimental**

[39, 43]

**mean value**

**et al.**

**et al.**

**et al.**

**et al.**

**et al**

**et al.**

**et al.**

**et al.**

**name of the** 

**author/s**

Newspaper Cardboard Cherry wood

18,289

19,955

19,815

19,962

24,766

22,857

19,284

16,573

22,580

18,539

20,189

2328

17,500

1345

waste

PP HDPE **Table 3.**

*The HHVs prediction based on ultimate and proximate analysis.*

18,277

19,016

17,057

19,947

27,545

29,904

16,427

16,575

19,310

15,569

19,797

4607

45,783

12,993

18,231

18,952

17,027

19,884

27,431

29,662

16,422

16,575

19,270

15,545

19,731

4544

42,772

11,520

17,500

18,333

17,283

19,050

25,253

24,774

17,036

16,572

19,509

15,929

18,931

3121

15,387

1772

17,131

17,723

16,339

18,704

25,422

25,461

16,199

16,571

18,363

14,956

18,687

3533

14,183

2252

**1**

**2**

**3**

**4**

**5**

**6**

**7**

**8**

**9**

**10**

31,063 **Estimation of the high heating value from proximate analysis**

35,369

47,760

56,915

49,491

48,980

48,857

48,887

46,715

46,137

46,017

7046

45,783 **Data comparison**

117

31,324

35,719

45,668

53,718

46,825

46,452

46,148

46,347

44,785

44,125

44,111

5925

42,772

670

19,103

19,320

20,320

19,726

29,810

26,972

20,860

20,226

30,974

23,025

23,034

4297

15,387

3823

18,777

18,883

18,440

19,035

28,107

25,189

18,794

18,117

29,682

21,328

21,635

4154

14,183

**Sheng and Azevedo**

**Tilman**

**REM model**

**Friedl et al.**

**Dulong 1**

**Yacio**

**Demirbas**

**Dulong 2**

**Boie**

**Scheurer- Kestner**

**HHV predicted mean value**

**STD all eq.**

**HHV experimental** 

**STD** 

**(Predicted v.s.** 

**experimental)**

[39, 43]

**1**

**2**

**3**

**4**

**5**

**6**

**7**

**8**

**9**

**10**

 **Estimation of the high heating value from ultimate analysis**

**Data comparison**

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods*

*DOI: http://dx.doi.org/10.5772/intechopen.80861*

3726


#### *Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods DOI: http://dx.doi.org/10.5772/intechopen.80861*

**Table 3.**

*The HHVs prediction based on ultimate and proximate analysis.*

*Analytical Pyrolysis*

close the calorimeter.

mum level.

introduced.

emptied.

l. Press and the gases are exhausted.

**4.4 Results, comparison, and discussions**

*4.4.1 Theoretical high heating value of pyrolysis chars*

HHV were performed in triplicates.

g. Transporting the bomb to the calorimeter. Attaching the bomb to the ignition fitment, then insert it into the calorimeter. Fit it in its intended place and then

h. Fill the IKA C200 calorimeter tank with water until the level indicator indicates the water level at a position between the minimum level and the maxi-

i. Digital operation with the device display. Enter the values corresponding to the sample mass and the lower calorific value of the bag into which the sample is

j. After the apparatus displays the value of the calorific value, the water tank is

m. Opening the sample, removing the filament and cleaning the crucible with alcohol.

All the calorimetric measurements for the determination of biochars and chars

The HHVs of the biomass and polymer-based materials were predicted by using 20 equations presented in **Table 1**. The ultimate and proximate analysis for each type of material, presented in **Table 2** were used for the application of the formulas. **Table 3** shows the newspaper, cardboard, cherry wood, PP and HDPE waste HHVpredicted values obtained using the equations presented in **Table 1**. To avoid confusion and compare more easily the results, all the predicted values were normalized, by using the same reference unit measure [kJ/kg]. The comparison of the data was made based on: the HHV predicted mean value generated by the equations, standard deviation (STD) by analyzing all the equations from each type of determination (ultimate or proximate analysis), HHV of the material obtained with the calorimeter (HHV experimental) and STD by comparing the predicted and experimental results. From the elemental analysis models, the HHVs predicted from biomass-based materials (newspaper, cardboard and cherry wood) varies between 21,273 and 23,034 kJ/kg, while the plastic-waste ranges between 44,111–46,017 kJ/kg with a STD of ≈6000–7000 kJ/kg. By comparing only, the data obtained using the equations, the trend lines plotted in **Figure 3** report homogenies correlation between the results for most equations. However there are some visible exceptions since for plastic based materials Eq. (3, 4) underestimate the predicted HHV with almost 30%, while Eq. (7) for plastic and Eqs. (7, 8, 11) for biomass-based waste overestimates it. For some correlations inconsistent results can be observed while comparing the mean HHV predicted v.s. HHV experimental. For a better evaluation of the correlation the mean absolute error (MAE) was determined. The MAE evaluates the accuracy of the HHV predicted to the experimental one. In this case, lower values tending to 0% indicate good accuracy of a specific correlation. The MAE negative values indicate the underestimation of the results, while the positive their

k. Positioning the gas removal device on the top of the calorimeter bomb.

**80**

**Figure 3.** *Comparison of the HHV-predicted values based on ultimate analysis.*

overestimation. Eqs. (5, 9, 10) and Eqs. (5, 7–12) can predict the HHVs for biomassbased wastes and plastics-based wastes respectively, with MAE lower than 10%, indicating their versatile applicability.

From the proximate analysis models, for all studied materials the HHVs predicted varies between ≈18,600 and 30,000 kJ/kg with a STD reaching to almost 12,000 kJ/kg for the plastic-based waste as shown in **Figure 4**. For plastic—based materials, the HHV predicated is different from HHV experimental, for all 10 studied equations. In all cases the predicted energetic value is underestimated. This is further strengthened by MAE that varies between −31 and −66%. In this case the validity of the correlations towards their universal usage on the defined type of materials is uncertain. Good correlation can be notice for cherry wood waste. The latter is confirmed by the mean percentage error that tends to zero and is lower than 15% for Eqs. (13–16), (19), (22). For the other biomass-based waste (newspaper and cardboard) adequate MAE varying between 4%–20% are registered for Eqs. (13–16, 19–22). Eqs. (17) and (18) are overestimating the predicted newspaper and cardboard HHV with 60–80%. By analysis the equations correlated with the number of elements considered, we can conclude that the heating value is mainly a function of ash content or volatile matter. The previews statement is support also by literature [25]. In conclusion the accuracy of the results increases with the numbers of elements correlated with ultimate and proximate analysis considered in the prediction formulas. Furthermore, higher correlations accuracies have been registered in the case of ultimate analysis usage. The current statement is supported by former investigations presented by Menikpura and Basnayake [47].

#### *4.4.2 Experimentally determined high heating value of pyrolysis chars*

The results concerning the caloric energy of the chars resulted from pyrolysis of the wood cherry and four PSW and PCW mixes (Mix 1, Mix 2, Mix 3, Mix 4) could be a support to provide energy fuels valuable for energy systems. From this point of view, it is evident to underline the energy content of the generated chars. So, a challenge for this experimental research was to discuss the way how type of waste marks changes on the high heating value of the pyrolysis chars. There were significant differences in the caloric value of the chars resulted from wood waste vs. light packaging wastes (LPW). These can be clearly observed in **Figure 5**.

In case of the cherry wood pyrolysis, the increase of process temperature leads to more energy valuable products. The maximum value of HHV (30,043 kJ/kg) was determined for the biochars obtained from pyrolysis at 600°C and marks these

**83**

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods*

as products comparable with a real coal (e.g., semi-anthracite coal—29,500 kJ/kg, bituminous coal—30,200 kJ/kg, anthracite coal—32,600 kJ/kg), while for plastic the maximum value of HHV was 31,378 kJ/kg, obtained at 500°C. If we consider the chars resulted from the LPW mixes, we can conclude there is not any linear increasing/decreasing of the HHV function of the pyrolysis process. Comparing the experimental determinations, it was revealed that for pyrolysis processing, 400°C produces chars with appropriated HHV as value in case of cherry wood, Mix 3 and Mix 4, 500°C in case of cherry biomass and Mix 4 and 600°C for case of cherry wood and Mix 1, respectively. It was already reported that heating value of lignocellulosic biomass type can greatly vary with climate and soil [48]. It is obviously that these factors strongly influence the HHV of wood and of the mixes analyzed in the present research. At lower process temperature of 400°C, for the plastic-based mixtures (Mix 2, Mix 3, Mix 4) the agglutination rate of the char produced increases. At this process temperature, during the experiments, the recovery of the char was obstructed by its high agglutination level, due to plastic incomplete decomposition. In this case, at industrial level, in mixture with other wastes, the deposition of the melted char on the side of the reactor walls might overload it, limiting its recovery from the pyrolysis chamber. In conclusion, the minimal recommend pyrolysis

process temperature in case of plastic waste presence should be 500°C.

*DOI: http://dx.doi.org/10.5772/intechopen.80861*

*Comparison of the HHV predicted values based on proximate analysis.*

*HHV of chars and biochars depending on the pyrolysis process temperature.*

**Figure 4.**

**Figure 5.**

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods DOI: http://dx.doi.org/10.5772/intechopen.80861*

**Figure 4.**

*Analytical Pyrolysis*

**Figure 3.**

indicating their versatile applicability.

*Comparison of the HHV-predicted values based on ultimate analysis.*

investigations presented by Menikpura and Basnayake [47].

*4.4.2 Experimentally determined high heating value of pyrolysis chars*

packaging wastes (LPW). These can be clearly observed in **Figure 5**.

The results concerning the caloric energy of the chars resulted from pyrolysis of the wood cherry and four PSW and PCW mixes (Mix 1, Mix 2, Mix 3, Mix 4) could be a support to provide energy fuels valuable for energy systems. From this point of view, it is evident to underline the energy content of the generated chars. So, a challenge for this experimental research was to discuss the way how type of waste marks changes on the high heating value of the pyrolysis chars. There were significant differences in the caloric value of the chars resulted from wood waste vs. light

In case of the cherry wood pyrolysis, the increase of process temperature leads to more energy valuable products. The maximum value of HHV (30,043 kJ/kg) was determined for the biochars obtained from pyrolysis at 600°C and marks these

overestimation. Eqs. (5, 9, 10) and Eqs. (5, 7–12) can predict the HHVs for biomassbased wastes and plastics-based wastes respectively, with MAE lower than 10%,

From the proximate analysis models, for all studied materials the HHVs predicted varies between ≈18,600 and 30,000 kJ/kg with a STD reaching to almost 12,000 kJ/kg for the plastic-based waste as shown in **Figure 4**. For plastic—based materials, the HHV predicated is different from HHV experimental, for all 10 studied equations. In all cases the predicted energetic value is underestimated. This is further strengthened by MAE that varies between −31 and −66%. In this case the validity of the correlations towards their universal usage on the defined type of materials is uncertain. Good correlation can be notice for cherry wood waste. The latter is confirmed by the mean percentage error that tends to zero and is lower than 15% for Eqs. (13–16), (19), (22). For the other biomass-based waste (newspaper and cardboard) adequate MAE varying between 4%–20% are registered for Eqs. (13–16, 19–22). Eqs. (17) and (18) are overestimating the predicted newspaper and cardboard HHV with 60–80%. By analysis the equations correlated with the number of elements considered, we can conclude that the heating value is mainly a function of ash content or volatile matter. The previews statement is support also by literature [25]. In conclusion the accuracy of the results increases with the numbers of elements correlated with ultimate and proximate analysis considered in the prediction formulas. Furthermore, higher correlations accuracies have been registered in the case of ultimate analysis usage. The current statement is supported by former

**82**

*Comparison of the HHV predicted values based on proximate analysis.*

**Figure 5.** *HHV of chars and biochars depending on the pyrolysis process temperature.*

as products comparable with a real coal (e.g., semi-anthracite coal—29,500 kJ/kg, bituminous coal—30,200 kJ/kg, anthracite coal—32,600 kJ/kg), while for plastic the maximum value of HHV was 31,378 kJ/kg, obtained at 500°C. If we consider the chars resulted from the LPW mixes, we can conclude there is not any linear increasing/decreasing of the HHV function of the pyrolysis process. Comparing the experimental determinations, it was revealed that for pyrolysis processing, 400°C produces chars with appropriated HHV as value in case of cherry wood, Mix 3 and Mix 4, 500°C in case of cherry biomass and Mix 4 and 600°C for case of cherry wood and Mix 1, respectively. It was already reported that heating value of lignocellulosic biomass type can greatly vary with climate and soil [48]. It is obviously that these factors strongly influence the HHV of wood and of the mixes analyzed in the present research. At lower process temperature of 400°C, for the plastic-based mixtures (Mix 2, Mix 3, Mix 4) the agglutination rate of the char produced increases. At this process temperature, during the experiments, the recovery of the char was obstructed by its high agglutination level, due to plastic incomplete decomposition. In this case, at industrial level, in mixture with other wastes, the deposition of the melted char on the side of the reactor walls might overload it, limiting its recovery from the pyrolysis chamber. In conclusion, the minimal recommend pyrolysis process temperature in case of plastic waste presence should be 500°C.

#### *Analytical Pyrolysis*

The closest value of HHV registered for cherry wood and Mix 1 confirming that these two materials have a similar chemical structure and composition. Since all types of biomass have similar carbon mass fraction they have a comparable HHV, between 16,200 and 21,600 kJ/kg [49]. This rule could explain the same tendency for the biochars resulted from wood and Mix 1, respectively. Another aspect to be considered is the ash content that lead to variation of the HHV of the biochar. Experiments of Brewer [50] lead to biochars from corn stover, switchgrass, and hardwood treated by pyrolysis and gasification processes. The results showed that is an inversely proportional relation between biomass ash content and the heating potential of the biochar.

### **5. Conclusions**

In this study analytical methods have been used for the HHV determination of different raw biomass, plastic waste and biomass-plastic waste mixtures and their by-products (biochar and char) resulted from the pyrolysis process. The main conclusion of the present research are listed:


**85**

**Author details**

provided the original work is properly cited.

Gabriela Ionescu and Cora Bulmău\*

University Politehnica of Bucharest, Bucharest, Romania

\*Address all correspondence to: cora4cora@gmail.com

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods*

*DOI: http://dx.doi.org/10.5772/intechopen.80861*

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods DOI: http://dx.doi.org/10.5772/intechopen.80861*

#### **Author details**

*Analytical Pyrolysis*

potential of the biochar.

conclusion of the present research are listed:

**5. Conclusions**

research.

prediction formulas.

volatile matter.

PSW 33%) 31,732 kJ/kg at 500°C.

The closest value of HHV registered for cherry wood and Mix 1 confirming that these two materials have a similar chemical structure and composition. Since all types of biomass have similar carbon mass fraction they have a comparable HHV, between 16,200 and 21,600 kJ/kg [49]. This rule could explain the same tendency for the biochars resulted from wood and Mix 1, respectively. Another aspect to be considered is the ash content that lead to variation of the HHV of the biochar. Experiments of Brewer [50] lead to biochars from corn stover, switchgrass, and hardwood treated by pyrolysis and gasification processes. The results showed that is an inversely proportional relation between biomass ash content and the heating

In this study analytical methods have been used for the HHV determination of different raw biomass, plastic waste and biomass-plastic waste mixtures and their by-products (biochar and char) resulted from the pyrolysis process. The main

• The comprehensive analysis of the scientific literature reveled that limited information is delivered in the regarding the energy potential of the chars and biochars produced by pyrolysis processing of the waste types analyzed in our

• The biomass and plastic wastes presented in this chapter store a significant quantity of energy that can be converted into different energy products depending on the correlation between feedstock properties, operational conditions of the available technology processes and the end use of the obtained products.

• The results generated by using the empirical equations mentioned in the present chapter demonstrates that their accuracy increases with the numbers of elements correlated with ultimate and proximate analysis considered in the

• In the absence of instrumentation for HHV determination, empirical dedicated formulas can be used based on the ultimate and proximate analysis of the material. The experimental determination of the individual elements and substances is required for further application of the correlations. Twenty prediction formulas for HHV were analyzed. The elemental analysis represents the most essential parameter for determining the fuel heat of combustion. For a better accuracy of the results, the authors suggest the usage of at least three types of different dedicated correlations, considering the main fuel characteristic of the studied fuel.

• The experimental results reported that ash content is the main function in the energy content of biochars/chars. The latter is confirmed by the empirical results, where the heating value is strongly influenced by the ash content or

• Our experimental research revealed the following maximum values for the HHVs of the chars and biochars produced by pyrolysis processes: cherry wood 30,043 kJ/kg at 600°C, PCW 28,335 kJ/kg at 600°C, PSW 36,378 kJ/kg at 500°C, Mix 3 (PCW 90% & PSW 10%) 24,174 kJ/kg at 400°C and Mix 4 (PCW 67% &

**84**

Gabriela Ionescu and Cora Bulmău\* University Politehnica of Bucharest, Bucharest, Romania

\*Address all correspondence to: cora4cora@gmail.com

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

### **References**

[1] https://www.windpowermonthly. com/article/1463710/denmark-movesstrengthen-renewable-energy-goals [Accessed: 2018-07-03]

[2] Antal MJ, Croiset E, Dai X, DeAlmeida C, Mok WSL, Norberg N, et al. High-yield biomass charcoal. Energy & Fuels. 1996;**10**(3):652-658. DOI: 10.1021/ef9501859

[3] Sun Y, Gao B, Yao Y, Fang J, Zhang M, Zhou Y, et al. Effects of feedstock type, production method, and pyrolysis temperature on biochar and hydrochar properties. Chemical Engineering Journal. 2014;**240**:574-578. DOI: 10.1016/J.CEJ.2013.10.081

[4] Demirbas A. Effects of temperature and particle size on bio-char yield from pyrolysis of agricultural residues. Journal of Analytical and Applied Pyrolysis. 2004;**72**(2):243-248. DOI: 10.1016/J.JAAP.2004.07.003

[5] Sarge SM, Hemminger W. Calorimetry Fundamentals, Instrumentation and Applications. John Wiley & Sons; 2014. p. 280. DOI: 10.1002/9783527649365

[6] Rodríguez AJA, Proupín CJ. Energy evaluation of materials by bomb calorimetry in thermal analysis. In: Fundamentals and Applications to Material Characterization. Universidade di Santiago; 2005. pp. 155-165

[7] U.S. Department of Energy. Annual Energy Review 1995, Energy Information Administration Report DOE/EIA-0384(95). Washington, D.C: U.S. DOE; 1996

[8] Organization for Economic Co-operation and Development, International Energy Agency. Energy Balances of OECD Countries, 1992-1993. Paris: OECD; 1995

[9] Subczynski WK, Markowska E, Sielewiesiuk J. Spin-label studies on phosphatidylcholine-polar carotenoid membranes: Effects of alkyl-chain length and unsaturation. Biochimica et Biophysica Acta. 1993;**1150**(2):173-181. DOI: 10.1016/0005-2736(93)90087-G

[10] James AM. Thermal and Energetic Studies of Cellular Biological Systems. Butterworth-Heinemann; 2016. 232 p. ISBN: 1483193551, 9781483193557

[11] Domalski ES, Jobe TL Jr, Milne TA. Thermodynamic Data for Biomass Conversion and Waste Incineration (No. SERI/SP-271-2839). Golden, CO (US)/ Washington, DC (US): National Bureau of Standards/Solar Energy Research Inst.; 1986

[12] Sheng C, Azevedo JLT. Estimating the higher heating value of biomass fuels from basic analysis data. Biomass and Bioenergy. 2005;**28**(5):499-507. DOI: 10.1016/j.biombioe.2004.11.008

[13] Miranda R, Sosa C, Bustos D, Carrillo E, Rodríguez-Cantú M. Characterization of pyrolysis products obtained during the preparation of bio-oil and activated carbon. In: Lignocellulosic Precursors Used in the Synthesis of Activated Carbon-Characterization Techniques and Applications in the Wastewater Treatment. InTech; 2012. pp. 77-92

[14] Rada EC. Present and future of SRF. Waste Management. 2016;**47**(2):155-156. DOI: 10.1016/j. wasman.2015.11.035

[15] Channiwala SA, Parikh PP. A unified correlation for estimating HHV of solid, liquid and gaseous fuels. Fuel. 2002;**81**(8):1051-1063. DOI: 10.1016/ S0016-2361(01)00131-4

[16] Tillman DA. Wood as an Energy Source. New York, NY, USA: Academic Press; 1978

**87**

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods*

[25] Liu JI, Paode RD, Holsen TM. Modeling the energy content of municipal solid waste using multiple regression analysis. Journal of the Air & Waste Management Association. 1996;**46**(7):650-656. DOI: 10.1080/10473289.1996.10467499

[26] Wahid FRAA, Saleh S, Samad NAFA. Estimation of higher heating value of torrefied palm oil wastes from proximate analysis. Energy Procedia. 2017;**138**:307-312. DOI: 10.1016/j.

[27] Demirbaş A, Demirbaş AH. Estimating the calorific values of

lignocellulosic fuels. Energy Exploration & Exploitation. 2004;**22**(2):135-143. DOI: 10.1080/00908319708908888

[28] Friedl A, Padouvas E, Rotter H, Varmuza K. Prediction of heating values of biomass fuel from elemental composition. Analytica Chimica Acta.

[29] Khan MA, Abu-Ghararah ZH. New

approach for estimating energy content of municipal solid waste. Journal of Environmental Engineering.

[30] Yacio. Waste characteristics. In: Report submitted to the Ministry of Housing and Local Government, Malaysia. Kuala Lumpur: Ministry of Housing and Local Government; 2000

[31] Demirbaş A. Relationships between lignin contents and heating values of biomass. Energy Conversion and Management. 2001;**42**(2):183-188. DOI: 10.1016/S0196-8904(00)00050-9

[32] García R, Pizarro C, Lavín AG, Bueno JL. Spanish biofuels heating value estimation, Part II: Proximate analysis. Fuel. 2014;**117**:1139-1147. DOI: 10.1016/j.

[33] Cordero T, Marquez F, Rodriguez-Mirasol J, Rodriguez J. Predicting

fuel.2013.08.049

2005;**544**(1-2):191-198

1991;**117**(3):376-380

egypro.2017.10.102

*DOI: http://dx.doi.org/10.5772/intechopen.80861*

[17] Vargas-Moreno JM, Callejón-Ferre AJ, Pérez-Alonso J, Velázquez-Martí B. A review of the mathematical models for predicting the heating value of biomass materials. Renewable and Sustainable Energy Reviews. 2012;**16**(5):3065-3083. DOI: 10.1016/j.

[18] Demirbaş A. Calculation of higher heating values of biomass fuels. Fuel. 1997;**76**(5):431-434. DOI: 10.1016/

[20] Dos Santos RG, Bordado JM. Design of simplified models for the estimation of higher heating value of refused derived fuels. Fuel. 2018;**212**:431-436. DOI: 10.1016/j.fuel.2017.10.062

[21] Han J, Yao X, Zhan Y, Oh SY, Kim LH, Kim HJ. A method for estimating higher heating value of biomass-plastic fuel. Journal of the Energy Institute. 2017;**90**(2):331-335. DOI: 10.1016/j.

[22] Shi H, Mahinpey N, Aqsha A, Silbermann R. Characterization,

thermochemical conversion studies, and heating value modeling of municipal solid waste. Waste Management. 2016;**48**:34-47. DOI: 10.1016/j.

[23] Özyuğuran A, Yaman S. Prediction of calorific value of biomass from proximate analysis. Energy Procedia. 2017;**107**:130-136. DOI: 10.1016/j.

[24] Kathiravale S, Yunus MNM, Sopian K, Samsuddin AH, Rahman RA. Modeling the heating value of municipal solid waste. Fuel. 2003;**82**(9):1119-1125. DOI: 10.1016/

S0016-2361(03)00009-7

rser.2012.02.054

fuel.2010.11.031

joei.2016.01.001

wasman.2015.09.036

egypro.2016.12.149

S0016-2361(97)85520-2

[19] Yin CY. Prediction of higher heating values of biomass from proximate and ultimate analyses. Fuel. 2011;**90**(3):1128-1132. DOI: 10.1016/j.

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods DOI: http://dx.doi.org/10.5772/intechopen.80861*

[17] Vargas-Moreno JM, Callejón-Ferre AJ, Pérez-Alonso J, Velázquez-Martí B. A review of the mathematical models for predicting the heating value of biomass materials. Renewable and Sustainable Energy Reviews. 2012;**16**(5):3065-3083. DOI: 10.1016/j. rser.2012.02.054

[18] Demirbaş A. Calculation of higher heating values of biomass fuels. Fuel. 1997;**76**(5):431-434. DOI: 10.1016/ S0016-2361(97)85520-2

[19] Yin CY. Prediction of higher heating values of biomass from proximate and ultimate analyses. Fuel. 2011;**90**(3):1128-1132. DOI: 10.1016/j. fuel.2010.11.031

[20] Dos Santos RG, Bordado JM. Design of simplified models for the estimation of higher heating value of refused derived fuels. Fuel. 2018;**212**:431-436. DOI: 10.1016/j.fuel.2017.10.062

[21] Han J, Yao X, Zhan Y, Oh SY, Kim LH, Kim HJ. A method for estimating higher heating value of biomass-plastic fuel. Journal of the Energy Institute. 2017;**90**(2):331-335. DOI: 10.1016/j. joei.2016.01.001

[22] Shi H, Mahinpey N, Aqsha A, Silbermann R. Characterization, thermochemical conversion studies, and heating value modeling of municipal solid waste. Waste Management. 2016;**48**:34-47. DOI: 10.1016/j. wasman.2015.09.036

[23] Özyuğuran A, Yaman S. Prediction of calorific value of biomass from proximate analysis. Energy Procedia. 2017;**107**:130-136. DOI: 10.1016/j. egypro.2016.12.149

[24] Kathiravale S, Yunus MNM, Sopian K, Samsuddin AH, Rahman RA. Modeling the heating value of municipal solid waste. Fuel. 2003;**82**(9):1119-1125. DOI: 10.1016/ S0016-2361(03)00009-7

[25] Liu JI, Paode RD, Holsen TM. Modeling the energy content of municipal solid waste using multiple regression analysis. Journal of the Air & Waste Management Association. 1996;**46**(7):650-656. DOI: 10.1080/10473289.1996.10467499

[26] Wahid FRAA, Saleh S, Samad NAFA. Estimation of higher heating value of torrefied palm oil wastes from proximate analysis. Energy Procedia. 2017;**138**:307-312. DOI: 10.1016/j. egypro.2017.10.102

[27] Demirbaş A, Demirbaş AH. Estimating the calorific values of lignocellulosic fuels. Energy Exploration & Exploitation. 2004;**22**(2):135-143. DOI: 10.1080/00908319708908888

[28] Friedl A, Padouvas E, Rotter H, Varmuza K. Prediction of heating values of biomass fuel from elemental composition. Analytica Chimica Acta. 2005;**544**(1-2):191-198

[29] Khan MA, Abu-Ghararah ZH. New approach for estimating energy content of municipal solid waste. Journal of Environmental Engineering. 1991;**117**(3):376-380

[30] Yacio. Waste characteristics. In: Report submitted to the Ministry of Housing and Local Government, Malaysia. Kuala Lumpur: Ministry of Housing and Local Government; 2000

[31] Demirbaş A. Relationships between lignin contents and heating values of biomass. Energy Conversion and Management. 2001;**42**(2):183-188. DOI: 10.1016/S0196-8904(00)00050-9

[32] García R, Pizarro C, Lavín AG, Bueno JL. Spanish biofuels heating value estimation, Part II: Proximate analysis. Fuel. 2014;**117**:1139-1147. DOI: 10.1016/j. fuel.2013.08.049

[33] Cordero T, Marquez F, Rodriguez-Mirasol J, Rodriguez J. Predicting

**86**

*Analytical Pyrolysis*

[Accessed: 2018-07-03]

DOI: 10.1021/ef9501859

[2] Antal MJ, Croiset E, Dai X, DeAlmeida C, Mok WSL, Norberg N, et al. High-yield biomass charcoal. Energy & Fuels. 1996;**10**(3):652-658.

[1] https://www.windpowermonthly. com/article/1463710/denmark-movesstrengthen-renewable-energy-goals

[9] Subczynski WK, Markowska E, Sielewiesiuk J. Spin-label studies on phosphatidylcholine-polar carotenoid membranes: Effects of alkyl-chain length and unsaturation. Biochimica et Biophysica Acta. 1993;**1150**(2):173-181. DOI: 10.1016/0005-2736(93)90087-G

[10] James AM. Thermal and Energetic Studies of Cellular Biological Systems. Butterworth-Heinemann; 2016. 232 p. ISBN: 1483193551, 9781483193557

[11] Domalski ES, Jobe TL Jr, Milne TA. Thermodynamic Data for Biomass Conversion and Waste Incineration (No. SERI/SP-271-2839). Golden, CO (US)/ Washington, DC (US): National Bureau of Standards/Solar Energy Research

[12] Sheng C, Azevedo JLT. Estimating the higher heating value of biomass fuels from basic analysis data. Biomass and Bioenergy. 2005;**28**(5):499-507. DOI: 10.1016/j.biombioe.2004.11.008

[13] Miranda R, Sosa C, Bustos D, Carrillo E, Rodríguez-Cantú M. Characterization of pyrolysis products obtained during the preparation of bio-oil and activated carbon. In: Lignocellulosic Precursors Used in the Synthesis of Activated Carbon-Characterization Techniques and Applications in the Wastewater Treatment. InTech; 2012. pp. 77-92

[14] Rada EC. Present and future of SRF. Waste Management. 2016;**47**(2):155-156. DOI: 10.1016/j.

[15] Channiwala SA, Parikh PP. A unified correlation for estimating HHV of solid, liquid and gaseous fuels. Fuel. 2002;**81**(8):1051-1063. DOI: 10.1016/

[16] Tillman DA. Wood as an Energy Source. New York, NY, USA: Academic

wasman.2015.11.035

S0016-2361(01)00131-4

Press; 1978

Inst.; 1986

[3] Sun Y, Gao B, Yao Y, Fang J, Zhang M, Zhou Y, et al. Effects of feedstock type, production method, and pyrolysis temperature on biochar and hydrochar properties. Chemical Engineering Journal. 2014;**240**:574-578. DOI: 10.1016/J.CEJ.2013.10.081

[4] Demirbas A. Effects of temperature and particle size on bio-char yield from pyrolysis of agricultural residues. Journal of Analytical and Applied Pyrolysis. 2004;**72**(2):243-248. DOI:

[6] Rodríguez AJA, Proupín CJ. Energy evaluation of materials by bomb calorimetry in thermal analysis. In: Fundamentals and Applications to Material Characterization. Universidade di Santiago; 2005.

[7] U.S. Department of Energy. Annual Energy Review 1995, Energy Information Administration Report DOE/EIA-0384(95). Washington, D.C:

[8] Organization for Economic Co-operation and Development, International Energy Agency. Energy

Balances of OECD Countries, 1992-1993. Paris: OECD; 1995

10.1016/J.JAAP.2004.07.003

[5] Sarge SM, Hemminger W. Calorimetry Fundamentals, Instrumentation and Applications. John Wiley & Sons; 2014. p. 280. DOI:

10.1002/9783527649365

pp. 155-165

U.S. DOE; 1996

**References**

heating values of lignocellulosics and carbonaceous materials from proximate analysis. Fuel. 2001;**80**:1567-1571. DOI: 10.1016/S0016-2361(01)00034-5

[34] Phichai K, Pragrobpondee P, Khumpart T, Hirunpraditkoon S. Prediction heating values of lignocellulosics from biomass characteristics. International Journal of Mining and Mineral Engineering. 2013;**7**:532-535. DOI: scholar.waset. org/1307-6892/16408

[35] Thipkhunthod P, Meeyoo V, Rangsunvigit P, Kitiyanan B, Siemanond K, Rirksomboon T. Predicting the heating value of sewage sludges in Thailand from proximate and ultimate analyses. Fuel. 2005;**84**:849-857. DOI: 10.1016/j.fuel.2005.01.003

[36] Soponpongpipat N, Sittikul D, Sae-Ueng U. Higher heating value prediction of torrefaction char produced from nonwoody biomass. Frontiers in Energy. 2015;**9**(4):461-471. DOI: 10.1007/ s11708-015-0377-3

[37] Kieseler S, Neubauer Y, Zobel N. Ultimate and proximate correlations for estimating the higher heating value of hydrothermal solids. Energy & Fuels. 2013;**27**:908-918. DOI: 10.1021/ ef301752d

[38] Parikh J, Channiwala SA, Ghosal GK. A correlation for calculating HHV from proximate analysis of solid fuels. Fuel. 2005;**84**:487-494. DOI: 10.1016/j. fuel.2004.10.010

[39] Ionescu G, Marculescu C, Badea A. Alternative solutions for MSW to energy conversion. University Politehnica of Bucharest Scientific Bulletin. 2010;**73**:243-254. ISSN: 1454-234x

[40] Ionescu G, Rada EC, Ragazzi M, Dal Maschio R, Ischia M, Mărculescu C. Packaging waste thermal treatment and pyro-products characterization

for power conversion. In: Proceedings of the 4th International Conference on Engineering for Waste and Biomass Valorisation, WasteEng12, Porto, Portugal, 10-13 September 2012. France: Mines d"Albi; 2012. pp. 892-897

[41] BIOBIB a DataBase for Biofuels. https://www.vt.tuwien.ac.at/biobib [Accessed: 2018-05-22]

[42] Telmo C, Lousada J, Moreira N. Proximate analysis, backwards stepwise regression between gross calorific value, ultimate and chemical analysis of wood. Bioresource Technology. 2010;**101**(11):3808-3815. DOI: 10.1016/j.biortech.2010.01.021

[43] Gheorghe (Bulmău) C. Contributions concerning the biomass pyrolysis processes [thesis]. University Politehnica of Bucharest; 2009

[44] Ionescu G. Critical analysis of pyrolysis and gasification applied to waste fractions with growing energetic content [doctoral dissertation]. University of Trento; 2012

[45] Bulmău C, Mărculescu C, Badea A, Apostol T. Pyrolysis parameters influencing the bio-char generation from wooden biomass. University Politehnica of Bucharest Scientific Bulletin-Serie C: Electrical Engineering. 2010;**72**(1):29-38. ISSN: 1454-234x

[46] Gheorghe (Bulmău) C, Marculescu C, Badea A, Dincă C, Apostol T. Effect of pyrolysis conditions on biochar production from biomass. In: Proceedings of the 3rd International Conference on Renewable Energy Sources, WSEAS. Tenerife, Canary Islands Spain: University of La Laguna; 2009. pp. 239-241

[47] Menikpura SNM, Basnayake BFA. New applications of 'Hess Law' and comparisons with models for determining calorific values of municipal solid wastes in the Sri

**89**

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods*

*DOI: http://dx.doi.org/10.5772/intechopen.80861*

Lankan context. Renewable Energy. 2009;**34**(6):1587-1594. DOI: 10.1016/j.

[48] Cai J, He Y, Yu X, Banks SW, Yang Y, Zhang X, et al. Review of physicochemical properties and analytical characterization of lignocellulosic biomass. Renewable and Sustainable Energy Reviews. 2017;**76**:309-322. DOI: 10.1016/j.

[49] Dufour A. Thermochemical Conversion of Biomass for the

10.1002/9781119137696

Production of Energy and Chemicals. John Wiley & Sons; 2016. DOI:

[50] Brewer CE. Biochar characterization and engineering [Graduate theses and dissertations]. Iowa State University;

renene.2008.11.005

rser.2017.03.072

2012

*Estimation of Energy Potential for Solid Pyrolysis By-Products Using Analytical Methods DOI: http://dx.doi.org/10.5772/intechopen.80861*

Lankan context. Renewable Energy. 2009;**34**(6):1587-1594. DOI: 10.1016/j. renene.2008.11.005

*Analytical Pyrolysis*

heating values of lignocellulosics and carbonaceous materials from proximate analysis. Fuel. 2001;**80**:1567-1571. DOI: 10.1016/S0016-2361(01)00034-5

for power conversion. In: Proceedings of the 4th International Conference on Engineering for Waste and Biomass Valorisation, WasteEng12, Porto, Portugal, 10-13 September 2012. France:

Mines d"Albi; 2012. pp. 892-897

[42] Telmo C, Lousada J, Moreira N. Proximate analysis, backwards stepwise regression between gross calorific value, ultimate and chemical

analysis of wood. Bioresource

[43] Gheorghe (Bulmău) C.

Politehnica of Bucharest; 2009

[44] Ionescu G. Critical analysis of pyrolysis and gasification applied to waste fractions with growing energetic content [doctoral dissertation]. University of Trento; 2012

[45] Bulmău C, Mărculescu C, Badea A, Apostol T. Pyrolysis parameters influencing the bio-char generation from wooden biomass. University Politehnica of Bucharest Scientific Bulletin-Serie C: Electrical Engineering. 2010;**72**(1):29-38. ISSN: 1454-234x

[46] Gheorghe (Bulmău) C, Marculescu C, Badea A, Dincă C, Apostol T. Effect

of pyrolysis conditions on biochar production from biomass. In: Proceedings of the 3rd International Conference on Renewable Energy Sources, WSEAS. Tenerife, Canary Islands Spain: University of La Laguna;

[47] Menikpura SNM, Basnayake BFA. New applications of 'Hess Law' and comparisons with models for determining calorific values of municipal solid wastes in the Sri

2009. pp. 239-241

Technology. 2010;**101**(11):3808-3815. DOI: 10.1016/j.biortech.2010.01.021

Contributions concerning the biomass pyrolysis processes [thesis]. University

[Accessed: 2018-05-22]

[41] BIOBIB a DataBase for Biofuels. https://www.vt.tuwien.ac.at/biobib

[34] Phichai K, Pragrobpondee P, Khumpart T, Hirunpraditkoon S. Prediction heating values of lignocellulosics from biomass characteristics. International Journal of Mining and Mineral Engineering. 2013;**7**:532-535. DOI: scholar.waset.

[35] Thipkhunthod P, Meeyoo V,

10.1016/j.fuel.2005.01.003

s11708-015-0377-3

ef301752d

fuel.2004.10.010

1454-234x

Rangsunvigit P, Kitiyanan B, Siemanond K, Rirksomboon T. Predicting the heating value of sewage sludges in Thailand from proximate and ultimate analyses. Fuel. 2005;**84**:849-857. DOI:

[36] Soponpongpipat N, Sittikul D, Sae-Ueng U. Higher heating value prediction of torrefaction char produced from nonwoody biomass. Frontiers in Energy. 2015;**9**(4):461-471. DOI: 10.1007/

[37] Kieseler S, Neubauer Y, Zobel N. Ultimate and proximate correlations for estimating the higher heating value of hydrothermal solids. Energy & Fuels. 2013;**27**:908-918. DOI: 10.1021/

[38] Parikh J, Channiwala SA, Ghosal GK. A correlation for calculating HHV from proximate analysis of solid fuels. Fuel. 2005;**84**:487-494. DOI: 10.1016/j.

[39] Ionescu G, Marculescu C, Badea A. Alternative solutions for MSW to energy conversion. University Politehnica of Bucharest Scientific Bulletin. 2010;**73**:243-254. ISSN:

[40] Ionescu G, Rada EC, Ragazzi M, Dal Maschio R, Ischia M, Mărculescu C. Packaging waste thermal treatment and pyro-products characterization

org/1307-6892/16408

**88**

[48] Cai J, He Y, Yu X, Banks SW, Yang Y, Zhang X, et al. Review of physicochemical properties and analytical characterization of lignocellulosic biomass. Renewable and Sustainable Energy Reviews. 2017;**76**:309-322. DOI: 10.1016/j. rser.2017.03.072

[49] Dufour A. Thermochemical Conversion of Biomass for the Production of Energy and Chemicals. John Wiley & Sons; 2016. DOI: 10.1002/9781119137696

[50] Brewer CE. Biochar characterization and engineering [Graduate theses and dissertations]. Iowa State University; 2012

### *Edited by Peter Kusch*

Analytical pyrolysis deals with the structural identification and quantitation of pyrolysis products with the ultimate aim of establishing the identity of the original material and the mechanisms of its thermal decomposition. The pyrolytic process is carried out in a pyrolyzer interfaced with analytical instrumentation such as gas chromatography (GC), mass spectrometry (MS), gas chromatography coupled with mass spectrometry (GC/ MS), or with Fourier-transform infrared spectroscopy (GC/FTIR). By measurement and identification of pyrolysis products, the molecular composition of the original sample can often be reconstructed.This book is the outcome of contributions by experts in the field of pyrolysis and includes applications of the analytical pyrolysis-GC/MS to characterize the structure of synthetic organic polymers and lignocellulosic materials as well as cellulosic pulps and isolated lignins, solid wood, waste particle board, and bio-oil. The thermal degradation of cellulose and biomass is examined by scanning electron micrography, FTIR spectroscopy, thermogravimetry (TG), differential thermal analysis, and TG/MS. The calorimetric determination of high heating values of different raw biomass, plastic waste, and biomass/plastic waste mixtures and their by-products resulting from pyrolysis is described.

Published in London, UK © 2019 IntechOpen © zhekos / iStock

Analytical Pyrolysis

Analytical Pyrolysis

*Edited by Peter Kusch*