This work investigates the effect of production scales (laboratory, bench, and pilot) by pyrolysis of Açaí (Euterpe oleracea Mart.) seeds at 450 °C and 1.0 atmosphere, on the yields of reaction products and acid value of bio-oils. The experiments were carried out in batch mode using a laboratory scale reactor of 143 mL, a bench scale reactor of 1.5 L, and a pilot scale reactor of 143 L (≈1:10:1000). The bio-oil was obtained in pilot scale, fractionated by distillation to produce biofuel-like fractions. The distillation of bio-oil was carried out in a laboratory column. The physical-chemistry properties (density, kinematic viscosity, acid value, and refractive index) of bio-oils and distillation fractions were determined. The qualitative analysis was determined by FT-IR and the chemical composition by GC-MS. The pyrolysis showed bio-oil yields from 4.37 to 13.09 (wt.%), decreasing with reactor volume. The acid value of bio-oils varied from 68.31 to 70.26 mg KOH/g. The distillation of bio-oil produced gasoline, light kerosene, and kerosene-like fuel fractions, and the yields were 16.16, 19.56, and 41.89 (wt.%), respectively. The physical-chemistry properties of distillation fractions increase with temperature. The FT-IR analysis of bio-oils and distillation fractions identified the presence of functional groups characteristic of hydrocarbons (alkenes, alkanes, aromatics, and aromatics rings) and oxygenates (carboxylic acids, ketones, esters, ethers, alcohols, phenols). The GC-MS identified 48.24 (area.%) hydrocarbons and 51.76 (area.%) oxygenates in the bio-oil produced in bench scale and 21.52 (area.%) hydrocarbons and 78.48 (area.%) oxygenates in the bio-oil produced in pilot scale. The gasoline-like fraction was composed by 64.0 (area.%) hydrocarbons and 36.0 (area.%) oxygenates, light kerosene-like fraction by 66.67 (area.%) hydrocarbons and 33.33 (area.%) oxygenates, and kerosene-like fraction by 19.87 (area.%) hydrocarbons and 81.13 (area.%) oxygenates.

In this study, we investigated the acid (HCl) and alkali (KOH) chemical activation of açaí seeds (Euterpe Oleraceae, Mart.) pre-treatment before pyrolysis at temperatures of 350–450 °C in order to assess how reactions proceed when affected by temperature. Chemical composition of bio-oil and aqueous phase were determined by GC-MS and FT-IR. The bio-char is characterized by XRD. For the activation with KOH, the XRD analysis identified the presence of Kalicinite (KHCO₃), the dominant crystalline phase in bio-char, while an amorphous phase was identified in bio-chars for the activation with HCl. The experiments have shown that bio-oil yield increases with temperature for the KOH activated biomass and decreases for the acid activated one. The KOH bio-oil is primarily composed of alcohols and ketones, showing the lowest acid values when compared with the HCl one, which is composed mainly of carboxylic acids and phenols. An increase in alcohol content and a decrease in ketones in the KOH bio-oil with temperature suggests conversion reactions between these two functions. For HCl bio-oil, carboxylic acid concentration increases with temperature while phenols decrease. For production of hydrocarbons, KOH activated biomass pyrolysis is better than acid-activated one, since no hydrocarbons were produced for HCl bio-oil.

Hydrothermal processing of biomass may be able to overcome a series of problems associated with the thermochemical conversion of lignocellulosic material into energy and fuels. Investigating the process parameters and an adequate process description is one of the first steps to being able to design and optimize a certain treatment concept. In the present article, we studied process evolution with respect to reaction time in order to evaluate structure changes and kinetics of corn stover decomposition in a hydrothermal reactor. The effect of the biomass-to-H₂O ratio was also investigated. A pilot-scale reactor of 18.75 L was used to conduct hydrothermal processing runs at 250 °C at different reaction times (60, 120 and 240 min) and biomass-to-H₂O ratios (1:10, 1:15 and 1:20). Solid phase products were characterized by thermogravimetry (TG), scanning electron microscopy (SEM), elemental composition (EDX), crystalline phases by X-ray diffraction (XRD) and surface area (BET). For the experiments with a constant reaction time, the yields of hydro-char, aqueous and gaseous phases varied between 31.08 and 35.82% (wt.), 54.59 and 60.83% (wt.) and 8.08 and 9.58% (wt.), respectively. The yields of hydro-char and gases tend to increase with higher biomass-to-H₂O ratios, while aqueous phase yields are lower when using lower ratios. As expected, the yields of liquid and gases are higher when using higher reaction times, but there is a reduction in hydro-char yields. TG showed that 60 min was not enough to completely degrade the corn stover, while 120 and 240 min presented similar results, indicating an optimized time of reaction between 120 and 240 min. SEM images, elemental composition and XRD of hydro-char showed that higher biomass-to-H₂O ratios increase the carbonization of corn stover. The surface area analysis of hydro-char obtained at 250 °C, 2.0 °C/min, a biomass-to-H₂O ratio of 1:10 and 240 min showed a surface area of 4.35 m²/g, a pore volume of 18.6 mm³/g and an average pore width of 17.08 μm. The kinetic of corn stover degradation or bio-char formation was correlated with a pseudo-first-order exponential model, exhibiting a root-mean-square error (r²) of 1.000, demonstrating that degradation kinetics of corn stover with hot-compressed H₂O, expressed as hydro-char formation, is well described by an exponential decay kinetics.

Catalytic upgrading of vapors from pyrolysis of triglycerides materials is a promising approach to achieve better conversions of hydrocarbons and production of liquid biofuels. Catalytic cracking often shows incomplete conversion due to distillation of initial reaction products and the addition of a second catalytic reactor, whereas pyrolytic vapors are made in contact to a solid catalyst was applied to improve the physical-chemical properties and quality of bio-oil. This work investigated the effect of catalyst content and reaction time by catalytic upgrading from pyrolysis vapors of residual fat at 450 °C and 1.0 atmosphere, on the yields of reaction products, physicochemical properties (density, kinematic viscosity, refractive index, and acid value), and chemical composition of organic liquid products (OLP), over a catalyst fixed bed reactor, in semi pilot scale. Pellets of red mud chemically activated with 1.0 M HCl were used as catalysts. The thermal catalytic cracking of residual fat show OLP yields from 54.4 to 84.88 (wt.%), aqueous phase yields between 2.21 and 2.80 (wt.%), solid phase yields (coke) between 1.30 and 8.60 (wt.%), and gas yields from 11.61 to 34.22 (wt.%). The yields of OLP increases with catalyst content while those of aqueous, gaseous and solid phase decreases. For all experiments, the density, kinematic viscosity, and acid value of OLP decreases with reaction time. The GC-MS of liquid reaction products identified the presence of hydrocarbons and oxygenates. In addition, the hydrocarbon content in OLP increases with reaction time, while those of oxygenates decrease, reaching concentrations of hydrocarbons up to 95.35% (area.). The best results for the physicochemical properties and the maximum hydrocarbon content in OLP were obtained at 450 °C and 1.0 atmosphere, using a catalyst fixed bed reactor, with 5.0% (wt.) red mud pellets activated with 1.0 M HCl as catalyst.

This work aims to investigate the effect of process temperature and catalyst content by pyrolysis and thermal catalytic cracking of (organic matter + paper) fraction from municipal household solid waste (MHSW) on the yields of reaction products (bio-oil, bio-char, H₂O, and gas), acid value, chemical composition of bio-oils, and characterization of bio-chars in laboratory scale. The collecting sectors of MHSW in the municipality of Belém-Pará-Brazil were chosen based on geographic and socio-economic database. The MHSW collected and transported to the segregation area. The gravimetric analysis of MHSW was carried out and the fractions (Paper, Cardboard, Tetra Pack, Hard Plastic, Soft Plastic, Metal, Glass, Organic Matter, and Inert) were separated. The selected organic matter and paper were submitted to pre-treatment of crushing, drying, and sieving. The experiments carried out at 400, 450, and 475 °C and 1.0 atmosphere, and at 475 °C and 1.0 atmosphere, using 5.0, 10.0, and 15.0% (wt.) Ca(OH)₂, in batch mode. The bio-oil was characterized for acid value. The chemical functions present in bio-oil were identified by FT-IR and the composition was identified by GC-MS. The bio-char was characterized by SEM, FT-IR, and XRD. The variance in mass (wt.%) for organic fractions of municipal household solid waste (OFMHSW), between 56.21 and 67.45% (wt.), lies with the interval of 56% (wt.) and 64% (wt.) of OFMHSW for middle- and low-income countries. The pyrolysis of MHSW fraction (organic matter + paper) shows bio-oil yields between 2.63 and 9.41% (wt.), aqueous phase yields between 28.58 and 35.08% (wt.), solid phase yields between 35.29 and 45.75% (wt.), and gas yields between 16.54 and 26.72% (wt.). The bio-oil yield increases with pyrolysis temperature. For the catalytic cracking, the bio-oil and gas yields increase slightly with CaO content, while that of bio-char decreases, and the H₂O phase remains constant. The GC-MS of liquid reaction products identified the presence of hydrocarbons (alkanes, alkenes, alkynes, cycloalkanes, and aromatics) and oxygenates (carboxylic acids, ketones, esters, alcohols, phenols, and aldehydes), as well as compounds containing nitrogen, including amides and amines. The acidity of bio-oil decreases with increasing process temperature and with aid Ca(OH)₂ as a catalyst. The concentration of hydrocarbons in bio-oil increases with increasing Ca(OH)₂-to-OFMHSW fraction ratio due to the catalytic deoxygenation of fatty acid molecules, by means of decarboxylation/decarbonylation, producing aliphatic and aromatic hydrocarbons.

This work investigated the influence of the reaction time and catalyst-to-residual fat ratio by catalytic upgrading from pyrolysis vapors of residual fat at 400 °C and 1.0 atmosphere, on the yields of reaction products, physicochemical properties (density, kinematic viscosity, and acid value) and chemical composition of bio-oils, over a catalyst fixed-bed reactor of activated carbon pellets impregnated with 10.0 M NaOH, in semi-pilot scale. The experiments were carried out at 400 °C and 1.0 atmosphere, using a process schema consisting of a thermal cracking reactor of 2.0 L coupled to a catalyst fixed-bed reactor of 53 mL, without catalyst and using 5.0%, 7.5%, and 10.0% (wt.) activated carbon pellets impregnated with 10.0 M NaOH, in batch mode. Results show yields of bio-oil decreasing with increasing catalyst-to-tallow ratio. The GC-MS of liquid reaction products identified the presence of hydrocarbons (alkanes, alkenes, ring-containing alkanes, ring-containing alkenes, and aromatics) and oxygenates (carboxylic acids, ketones, esters, alcohols, and aldehydes). For all the pyrolysis and catalytic cracking experiments, the hydrocarbon selectivity in bio-oil increases with increasing reaction time, while those of oxygenates decrease, reaching concentrations of hydrocarbons up to 95.35% (area).