**1. Introduction**

The world's oil reserves are not eternal. Exploitation for fuel increases emissions of greenhouse gases that contribute to climate change. Renewable biomass is a promising alternative to petroleum-based products as a source of bio-energy and other bioproducts [1], as the chemical value. The condensed Biogas is a type of liquid fuel made from biomass materials. As a kind of new cheap bio-energy, clean, green, bio-oil is considered an attractive option instead of conventional fuel in the aspect of reducing environmental pollution [2].

This study is motivated by a desire for development of natural resources to begin we take as cistus products. The study consisted of pyrolysis byproducts cistus

ladanifer [3]. The cistus pyrolysis regenerates solid carbon-rich products (char) and condensable gaseous products (tar) and non-condensable (hydrocarbons). The process of pyrolysis is the newest part of renewable energy, has been set up and provides the benefits of a liquid product—bio-oil—which can be easily stored and transported and used as a fuel, vector energy and a source of chemicals. Bio-oils have been successfully tested in engines, turbines and boilers, and were up graded to high quality hydrocarbon fuels but currently unacceptably energy and financial cost [4].

The slow pyrolysis is often linked to coal production and fast pyrolysis has been linked to the production of bio-oil. The slow pyrolysis of biomass produces a high content of carbon [5]. Pyrolysis safflower seeds *(Carthamus tinctorius L.)* of particle size between 0.85 and 1.25 mm with a heating rate between 10 and 100°C.min<sup>1</sup> and the flow rate of nitrogen equals 100 cm3 .min<sup>1</sup> , the maximum yield was at 600°C for bio-oil and expensive parallel 53 and 17%. The effect of pyrolysis temperatures, the particle size and the rate of heating on the yield of the apricot kernel shells to pyrolysis temperatures range from 350 to 700°C with a heating rate ranges from 7 at 10°C.min<sup>1</sup> . For the lower heating rate of 10°C.min<sup>1</sup> , the carbonization yield is increased from 35.2 to 29.4%, as the final pyrolysis temperature was raised from 400 to 550°C. Same results were also observed by Gerc el [6], who studied the effects of different pyrolysis temperatures and heating rates on pyrolysis *(acanthium Onopordum L.)* When the temperature pyrolysis increased from 350 to 700°C the carbonization yield was increased from 38.3 to 24.1% with a rate of 7°C.min<sup>1</sup> heating. The decrease in the carbonization yield with increase in temperature could be due to either a larger primary decomposition of biomass at a temperature above or in the secondary decomposition of the tank [7–10]. The gas yield increased from 38 to 43%, with the same amount of increase in temperature. When the temperature increases [11]. *Yorgun et al* studied the fast pyrolysis of sunflower cakes in a tubular reactor. The effect of the final temperature, nitrogen flow rate and particle size on the performance of pyrolysis products were studied. The maximum yield of oil 45% by weight was obtained in the pyrolysis temperature of 550°C, with a flow rate of 1–300 cm3 .min<sup>1</sup> sweep gas and the particle size of 0425 to 0850 mm [12, 13].

After a series of studies of characterization of the seeds and shells of cistus by the different techniques of analysis, the determination of the percentages in carbon, oxygen, hydrogen, and nitrogen as well as the determination of the percentages in humidity, ash, fixed carbon, and volatile products, by the elementary analysis of the biomass, we give a clear idea on the pyrolysis of the used biomass. The knowledge of the above-mentioned data creates a good ground for the study of the different factors that influence the yield of bio-oil obtained by pyrolysis. In this chapter, we will study three main parameters that are: the effect of temperature, the effect of granulometry, and the effect of the heating speed on the yield of the two biomasses used.

## **2. Materials and methods**

#### **2.1 Raw materials**

Biomass is the whole of the organic products, plants, and animals used for energy or agronomic purposes. The term biomass covers a very broad field: forestry waste, industrial waste, agricultural waste, the fermentable fraction of household waste and food industries, landfill biogas, or methanization products (sewage sludge, landfills, etc. … ). In this chapter, the different experimental campaigns were carried out using two types of biomass:

*Valorization of Forest Waste for the Production of Bio-oils for Biofuel and Biodiesel DOI: http://dx.doi.org/10.5772/intechopen.105366*

We took the initiative to study two types of biomass (**Figure 1**), one with little ash and the other with a lot more ash, in order to compare the different results and to be able to provide solutions for each type of biomass exploited. The main characteristics of the biomasses used are presented below.

#### **2.2 Sample characterization**

#### *2.2.1 Determination of the moisture content*

The moisture or water content designated by W of a sample is the ratio between the mass of water contained in the sample to its anhydrous mass, if we use its total mass this:

This ratio will be designated by W.

$$\mathbf{W} = \frac{(\mathbf{m}\_0 - \mathbf{m}\_\mathbf{a})}{\mathbf{m}\_\mathbf{a}} \ast \mathbf{100} \tag{1}$$

Moisture is determined by subjecting a sample of known mass to oven drying (103°C) for 24 hours until the mass becomes constant. The humidity can be expressed as a percentage.

Relative to the anhydrous mass:

$$\mathbf{W}\_0 = \frac{(\mathbf{m}\_0 - \mathbf{m}\_\mathbf{a})}{\mathbf{m}\_\mathbf{a}} \ast \mathbf{100} \tag{2}$$

Or m0: Total wet mass of the sample in (g); and ma: Anhydrous mass in (g).

#### *2.2.2 Determination of ash*

The cistus seeds and these shells are impregnated samples were incinerated at 600° C, to a constant mass in a muffle furnace.

#### **Figure 1.** *(a) Plant with fruit; (b) seeds; (c) seed powder; and (d) plant with flower; (e) shells; and (f) shell powder.*

The ash content, expressed as a percentage, is given by the equation:

$$\text{Ash } (\%) = \frac{(\text{m}\_1 - \text{m}\_{\text{cr}})}{(\text{m}\_2 - \text{m}\_{\text{cr}})} \ast \mathbf{100} \tag{3}$$

Where, mcr: Mass of the empty crucible (g); m1: Mass of the crucible and the ashes (g); and m2: Mass of the crucible and the biomass intake (g).

#### *2.2.3 Determination of volatile matter and fixed carbon*

The volatile matter represents the vapors of organic compounds and gases released by the biomass during pyrolysis, while the carbonaceous matter is the solid residue of carbon that remains after volatilization. Determination of volatile matter and fixed carbon for each sample was performed at 21°C.min�<sup>1</sup> under an inert atmosphere for seeds and 40°C.min�<sup>1</sup> for shells in a fixed bed pyrolysis reactor.

The volatile matter is determined by the formula:

$$\text{Mat.Vol}\,(\%) = \frac{(\text{m}\_{\text{a}} - \text{m}\_{\text{v}})}{\text{m}\_{\text{0}}} \ast \text{100} \tag{4}$$

Where: m0: Initial mass of the sample; ma: Mass of the dry sample (g); mv: Mass of the devolatilized sample (g); mC: Mass of ash (g).

The difference between the mass of the devolatilized sample (mv) and that of the ash (mC) represents the fixed carbon, designated by C. Fixed, whose mass percentage is given by the equation.

$$(\text{@})\,\,\text{C.Fixed} = \frac{(\text{m}\_{\text{V}} - \text{m}\_{\text{c}})}{\text{m}\_{\text{0}}} \ast 100\tag{5}$$

The results of the various analyses are summarized in **Table 1**.

#### *2.2.4 Elementary analyses*

The values measured are comparable to the results obtained by the pyrolysis of olive stones [1, 2] and those obtained by the pyrolysis of castor oil [14–17]. The contents of sulfur and nitrogen obtained by the different samples are low compared to the other references. **Table 2** presents the elemental composition of pyrolysis byproducts in the literature and the values obtained from different samples in this study.

According to the results obtained our biomass presents a significant percentage in C which is higher compared to other biomasses such as olive seed, and castor for


**Table 1.**

*Characterization of different samples studied.*

*Valorization of Forest Waste for the Production of Bio-oils for Biofuel and Biodiesel DOI: http://dx.doi.org/10.5772/intechopen.105366*


**Table 2.**

*Elemental composition of same biomass compared with cistus seeds and shells.*

example which does not exceed 59%, and for wood and coconut shells it is equal to 53.9 and 57.3% respectively [19]. On the other hand, the other elements like Oxygen, Nitrogen, Hydrogen, and Sulfur are lower than the biomasses quoted in **Table 2**. These values give the advantage to study the seeds and the shells of cistus for the production of bio-oils with the aim of transforming them into biofuels which are the vectors of actuality.
