**1. Introduction**

During the processing of açaí juice from açaí (*Euterpe oleracea*, Mart) seeds *in nature*, a native palm of natural occurrence in the Amazon region, belonging to the family Arecaceae and compassing approximately 200 genera and about 2600 species, distributed predominantly in tropical and subtropical areas [1], a by-product is produced and/or discharged, the açaí seeds, posing a huge environmental problem of solid waste management in Belém metropolitan region, as well as in the municipalities around the city of Belém-Pará-Brazil.

between 39.83 and 40.29% (wt.), lignin between 4.00 and 8.93% (wt.), ash between 0.15 and 1.68% (wt.), moisture between 10.15 and 39.39% (wt.), protein between 5.02 and 7.85% (wt.), 0.83% (wt.) fixed carbon, and 7.82% (wt.) volatile matter approximately [5–9]. A process that makes it possible for the use of açaí seeds, an oil-fiber seed rich lignin-cellulose-based mate-

Fractional Distillation of Bio-Oil Produced by Pyrolysis of Açaí (*Euterpe oleracea*) Seeds

http://dx.doi.org/10.5772/intechopen.79546

63

In the last years, several process schemes have been proposed to remove oxygenate compounds from biomass-derived bio-oils, including molecular distillation to separate water and carboxylic acids from pyrolysis bio-oils [17–19], fractional distillation to isolate chemicals and improve the quality of bio-oil [20–25], liquid-liquid extraction using organic solvents and water to recover oxygenate compounds of bio-oils [26, 27]. Non-conventional separation methods using aqueous salt solutions for phase separation of bio-oils have been also applied [28]. Recently, the bio-oil obtained by pyrolysis of açaí seeds in nature have been upgraded by fractional distillation, as described in detail as follows [15, 16]. Guerreiro et al. [15, 16] investigated the influence of column height by fractional distillation of bio-oil obtained by pyrolysis of açaí seeds at 350°C in pilot scale using Vigreux columns of 10 and 30 cm. The yields of gasoline were 6.60 and 7.12% (wt.), while that of kerosene were 11.05 and 12.64 (wt.), respectively, for columns of 10 and 30 cm, showing no significant variation. The acid value of gasoline-like fraction using Vigreux column of 10 and 30 cm were 17.08 and 16.79 mg KOH/g, respectively, while that of kerosene were 62.34 and 59.35 mg KOH/g, respectively, showing no significant variation. In addition, the kinematic viscosity of gasoline-like fraction using

/s, respectively, while that of kerosene were

/s, a variation between 8.23 and 23.27% showing that kinematic viscosity is

rial, of low quality for producing liquid and gaseous fuels is pyrolysis [15, 16].

more sensitive to the influence of column height, decreasing with column height.

In this work, the pyrolysis of Açaí seeds (*Euterpe oleracea*, Mart) has been systematically investigated in pilot scale at 450°C 1.0 atmosphere to produce a bio-oil, a pyrolysis reaction liquid product, been submitted to fraction distillation carried out in a laboratory-scale column (Vigreux Column) according to the boiling temperature range of fossil fuels to study the feasibility of producing fossil fuels like fractions (gasoline, kerosene, and diesel), as well as the morphology of solid phase products (coke), of açaí seeds (*Euterpe oleracea*, Mart) pyrolysis process at 450°C.

The seeds of Açaí (*Euterpe oleracea*, Mart) obtained in a small Store of Açaí Commercialization, located in the District of Guamã, Belém-Pará-Brazil. **Figure 1** shows the anatomy of aça *<sup>i</sup>* ́ fruits (cross section): (1) Embryo, (2) Endocarp, (3) Scar, (4) Pulp, (5) Pericarp + Tegument,

The seeds of Açaí (*Euterpe oleracea*, Mart) are submitted to drying at 105°C using a pilot oven with air recirculation (SOC, FABBE, Ltd, Brazil, Model: 170) for a period of 24 h. Afterward,

columns of 10 and 30 cm were 1.58 and 1.45 mm<sup>2</sup>

**2.2. Pre-treatment of açaí (***Euterpe oleracea***, Mart) seeds**

4.04 and 3.10 mm<sup>2</sup>

**2.1. Materials**

and (6) Mesocarp.

**2. Materials and methods**

The State of Pará is the largest national producer of açaí with 1,012,740 ton/year of fruits [2], being the production due to extractive 198,149 tons/year of fruits in the crop year 2014 [3], representing 55.4% (wt.) of the national production of extractive açaí in the crop year 2014, and the production due to agricultural systems using a planted area of 154,500 hectare, was 814,590 tons in the year 2014. Of the total 1,012,740 tons/year of fruits, 8,405,742 tons/year is a residue (açaí seeds) representing approximately 83% (wt.).

The metropolitan region of Belém-Pará-Brazil, capital the State of Pará, has approximately 10,000 stores of açaí commercialization, producing an average of 200 kg açaí seeds/day per store, thus producing around 2000 tons residue/day [4]. In 2015, there was a growth of 27.35% (wt.) in production, 10.86% (wt.) in planted area and 14.88% (wt.) on the specific production yield, compared to 2014 [2]. The seed of açaí is an oil-fiber seed, and according to the literature, constituted by a small solid endosperm attached to a tegument, rich in cellulose with approximately 53.20% (wt.), hemicelluloses 12.26% (wt.), lignin 22.30% (wt.), as well as 3.50% lipids (wt.) [5–9].

In a scenery, the modern industrial society focuses on minimization of global warming and CO<sup>2</sup> emission, as well as energy efficient supply systems and less consumption of fossil-based fuels. To achieve this, the use of renewable energy resources is essential [10]. In this context, processes that minimize the industrial and agro-industrial residues either by reusing or recycling them result in energetic and environmental benefits to the global society. In addition, recycling industrial and agro-industrial residues enables to use raw materials of low cost, making it possible to increase the economic viability of biofuels' production [11].

Among the most important renewable energy sources, this biomass is considered as an important one, since it could be a suitable alternative for conventional fossil fuels [12]. In addition, biomass energy producing systems may be implemented not only close to industrial and agro-industrial production systems, but also in any location where vegetable species can be grown and/or domestic animals are reared [12]. The systematic use of biomass makes it possible to reduce global warming compared to fossil fuel energy systems, as all the vegetable species use and store CO<sup>2</sup> for the photosynthesis process [13]. CO<sup>2</sup> stored in the plant is released when the plant material is burned and/or decays [12, 13]. Thus, by replanting the crops, the new growing vegetable species can use the CO<sup>2</sup> produced by burning vegetable species, as in the carbonization processes (e.g., pyrolysis), and hence contributing to close the carbon dioxide cycle, as reported in the literature by Kelli et al. [14].

The residual açaí seeds, an oil-fiber seed rich lignin-cellulose material, whose centesimal composition reported in the literature is constituted of lipids between 1.65 and 3.56% (wt.), total fibers between 29.69 and 62.75% (wt.), hemicellulose between 9.01 and 14.19% (wt.), cellulose between 39.83 and 40.29% (wt.), lignin between 4.00 and 8.93% (wt.), ash between 0.15 and 1.68% (wt.), moisture between 10.15 and 39.39% (wt.), protein between 5.02 and 7.85% (wt.), 0.83% (wt.) fixed carbon, and 7.82% (wt.) volatile matter approximately [5–9]. A process that makes it possible for the use of açaí seeds, an oil-fiber seed rich lignin-cellulose-based material, of low quality for producing liquid and gaseous fuels is pyrolysis [15, 16].

In the last years, several process schemes have been proposed to remove oxygenate compounds from biomass-derived bio-oils, including molecular distillation to separate water and carboxylic acids from pyrolysis bio-oils [17–19], fractional distillation to isolate chemicals and improve the quality of bio-oil [20–25], liquid-liquid extraction using organic solvents and water to recover oxygenate compounds of bio-oils [26, 27]. Non-conventional separation methods using aqueous salt solutions for phase separation of bio-oils have been also applied [28]. Recently, the bio-oil obtained by pyrolysis of açaí seeds in nature have been upgraded by fractional distillation, as described in detail as follows [15, 16]. Guerreiro et al. [15, 16] investigated the influence of column height by fractional distillation of bio-oil obtained by pyrolysis of açaí seeds at 350°C in pilot scale using Vigreux columns of 10 and 30 cm. The yields of gasoline were 6.60 and 7.12% (wt.), while that of kerosene were 11.05 and 12.64 (wt.), respectively, for columns of 10 and 30 cm, showing no significant variation. The acid value of gasoline-like fraction using Vigreux column of 10 and 30 cm were 17.08 and 16.79 mg KOH/g, respectively, while that of kerosene were 62.34 and 59.35 mg KOH/g, respectively, showing no significant variation. In addition, the kinematic viscosity of gasoline-like fraction using columns of 10 and 30 cm were 1.58 and 1.45 mm<sup>2</sup> /s, respectively, while that of kerosene were 4.04 and 3.10 mm<sup>2</sup> /s, a variation between 8.23 and 23.27% showing that kinematic viscosity is more sensitive to the influence of column height, decreasing with column height.

In this work, the pyrolysis of Açaí seeds (*Euterpe oleracea*, Mart) has been systematically investigated in pilot scale at 450°C 1.0 atmosphere to produce a bio-oil, a pyrolysis reaction liquid product, been submitted to fraction distillation carried out in a laboratory-scale column (Vigreux Column) according to the boiling temperature range of fossil fuels to study the feasibility of producing fossil fuels like fractions (gasoline, kerosene, and diesel), as well as the morphology of solid phase products (coke), of açaí seeds (*Euterpe oleracea*, Mart) pyrolysis process at 450°C.
