Fast Pyrolysis Process Research Articles

Effect of feedstocks and free-fall pyrolysis on bio-oil and biochar attributes

This study evaluates the potential of a mixed fast and slow pyrolysis process for the conversion of four feedstocks (i.e., hybrid poplar, maple, pine, and sugarcane bagasse) into bio-oil and biochar. The novelty of this study lies within the integration of a free-fall reactor with a batch reactor to take advantage of both fast and slow pyrolysis, and adapt conversion parameters (e.g., carrier gas pressure, feedstock particle size, bulk density, reactor height, and path tortuosity) to maximize the desired product quality and yields. Thermogravimetric analysis was used to provide insight into the thermal degradation of the specified feedstock. Biomass samples were pyrolyzed at 500–550 °C, and the conversion products were evaluated. Biochar properties were characterized using proximate and ultimate analyses and surface area. Bio-oil characterization was obtained by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), Fourier transform infrared (FTIR) spectroscopy, and thermal stability testing. GC-MS identified dominant bio-oil compounds, such as levoglucosan, furfural, and acetic acid. ESI detected molecular weights that are higher than average, necessitating further in-situ cracking (e.g., thermal or catalytic). FTIR showed similar peak patterns and functional groups across the feedstock. The results show that maple produced the greatest biochar yield at 56%, while hybrid poplar had the greatest bio-oil yield at 38%. Among the feedstocks, bio-oil produced from hybrid poplar presents a promising oil with the lowest moisture content (<20%), high phenol content, and the most thermally stable properties, while bio-oil from pine had the next best thermal stability, but with the highest content of levoglucosan (a favorable platform molecule). Analytical results are compared to prior studies to identify the advantages and disadvantages of the free-fall fast pyrolysis reactor. Shortcomings of the current reactor configuration are identified, along with the direction for future studies.

Fast pyrolysis of Beauty Leaf Fruit Husk (BLFH) in an auger reactor: Effect of temperature on the yield and physicochemical properties of BLFH oil

This study investigated the effect of temperature on the yield and quality of pyrolysis oil produced from Beauty Leaf Fruit Husk (BLFH) using fast pyrolysis process. The BLFH was subjected to fast pyrolysis process using an auger reactor wherein the temperature was varied from 400 °C to 550 °C with 50 °C interval. The residence time of 3 min 20 s and the feedstock particle size of less than 1 mm were used in this study to produce bio-oil. The bio-oil yield was highest (∼45%) at 500 °C. At these conditions, the biochar and syngas yields were ∼33% and ∼22%, respectively. Analysis of the bio-oil showed the presence of 9 functional groups, with the phenol, aromatics and alcohol groups dominating the others. The amine group was present at the lowest concentration. It was also found that at 500 °C, concentration of carbon and the calorific val1ue were the highest and concentration of oxygen and water content were the lowest. The values of this combination of different elements and physicochemical properties can be referred as the best combination. The kinematic viscosity and density were decreased by around 15% and 7%, respectively as the pyrolysis temperature was increased from 400 °C to 550 °C. Other properties such as calorific value, flash point and cetane number did not exhibit substantial differences across the temperature treatments. Based on these results, it can be concluded that the BLFH will serve as a suitable source to produce renewable energy like bio-oil.

Fast pyrolysis of bagasse catalyzed by mixed alkaline-earth metal oxides for the selective production of 4-vinylphenol

4-Vinylphenol (4-VP) is a value-added phenol compound, which can be obtained from the pyrolysis of herbaceous biomass, and its yield can be further improved through the in-situ catalytic fast pyrolysis process. Herein, a barium-magnesium mixed metal oxide (BaMg-MMO) catalyst was developed and employed for the selective production of 4-VP from bagasse fast pyrolysis. The effects of Ba/Mg molar ratio in the BaMg-MMO catalyst, pyrolytic temperature, catalyst-to-bagasse (CA-to-BA) ratio were carefully investigated based on pyrolysis-chromatography/mass spectrometry (Py-GC/MS) tests. The 4-VP yield reached a maximal of 7.3 wt% with the corresponding selectivity of 44.4% at 300 °C under the Ba/Mg molar ratio of 1:1 and the CA-to-BA ratio of 4:1, compared with that of 5.0 wt% in the non-catalytic process. Moreover, a series of lab-scale fast pyrolysis tests of bagasse were carried out in a fixed bed reactor using BaMg-MMO with a Ba/Mg molar ratio of 1:1. The highest 4-VP yield and selectivity were 7.1 wt% and 56.6% at 300 °C with the CA-to-BA ratio of 1:1. The results indicated that BaMg-MMO could provide a promising catalytic performance on the formation of 4-VP during the fast pyrolysis of bagasse.

Fast Pyrolysis Bio-Oil-Based Epoxy as an Adhesive in Oriented Strand Board Production.

The objectives of this study were to utilize bio-oil-based epoxy resin in oriented strand board (OSB) production and investigate the effect of bio-oil substitution in epoxy resin as an adhesive for OSB production. Bio-oil was produced by the fast pyrolysis (FP) process using southern yellow pine (Pinus spp.). Bio-oil-based epoxy resin was synthesized by the modification of epoxy resin with FP bio-oil at various substitution levels. Acetone extraction using a Soxhlet process indicated a superior cured reaction of bio-oil and epoxy resin at 20% bio-oil substitution. FTIR spectra corroborated the Soxhlet extraction with the removal of the epoxide peak signature within the cross-linked polymer. Images from the scanning electron microscopy suggested bulk phase homogeneity. OSB panels were tested according to ASTM D1037-12. The modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength, and water resistance (thickness swell and water absorption) properties of the OSB panels were feasible at bio-oil substitution up to 30% in the epoxy resin system.

Fractional Composition Analysis for Upgrading of Fast Pyrolysis Bio-Oil Produced from Sawdust

We can prevent climate change by reducing greenhouse gas (GHG) emissions caused by fossil fuel usage through introducing alternative fuels such as bio-oil. The fast pyrolysis process used for wood materials has recently gained substantial attention as an approach to produce bio-oil worldwide and in Korea as well. Bio-oil from fast pyrolysis contains highly oxygenated compounds and phenolics, thereby requiring upgrading processes, such as deoxygenation and condensation, for high-end use. To determine an efficient upgrading method for fast pyrolysis bio-oil (FPBO), one needs to elucidate its composition and classify it into chemical groups. We analyzed the composition of fractionized FPBO toward high-end use. FPBO was separated into two layers by adding distilled water: (a) the water-soluble phase, and (b) the oil phase, whereas liquid-liquid extraction and multi-step separation were applied for fractionization, respectively. The fractions were obtained, and their chemical groups were analyzed by gas chromatography time-of-flight mass spectrometry (GC×GC-TOF/MS). The water phase was separated into two fractions and classified into the main chemical groups of phenolics (9%) and heterocyclics (31%). The oil phase, which was separated into four fractions, was classified into the main chemical groups of phenolics (32%) and heterocyclics (23%). Our findings can help to upgrade products for high-end use.

Pyrolysis of Methyl Ricinoleate: Distribution and Characteristics of Fast and Slow Pyrolysis Products.

A stable temperature site and the speed of heating the feedstocks play a key role in pyrolysis processes. In this study, the product distribution arising from pyrolysis of methyl ricinoleate (MR) at 550 °C with low and high heating rates was first studied by pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). The results show that fast pyrolysis of MR favored the production of undecylenic acid methyl ester (UAME) and heptanal (HEP). Density functional theory (DFT) calculations were employed to reveal the UAME and HEP formation process from pyrolysis of MR. The bond dissociation energies (BDEs) of C–C bonds in MR showed that the C11–C12 bond is the weakest. This suggests that UAME and HEP are two major products. The process of slow and fast MR pyrolysis was the dehydration-first and the pyrolysis-first trend, respectively. The calculated activation energies of MR pyrolysis to UAME and HEP and MR dehydration to 9,12-octadecadienoic acid methyl ester were 287.72 and 238.29 kJ/mol, respectively. The much higher product yields obtained in the fast pyrolysis reactors than those from conventional tubular reactors confirmed the proposed process.

Study on the Staged and Direct Fast Pyrolysis Behavior of Waste Pine Sawdust Using High Heating Rate TG-FTIR and Py-GC/MS.

To understand the fast pyrolysis kinetics and product evolution of waste pine sawdust, high heating rate thermogravimetry-Fourier transform infrared (TG-FTIR) was used to obtain the kinetic parameters and the chemical groups formed during the pyrolysis process, while pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was used to investigate the detailed compositions of products under the staged (seven stages from 300 to 600 °C) and direct fast pyrolysis process. Spectral bands were identified for acids, alcohols, aldehydes, aromatics, esters, ethers, hydrocarbons, ketones, phenols, and sugars. Research found that the apparent activation energy for fast pyrolysis is much higher than that of slow pyrolysis. The evolution of CO2 is the major deoxygenation route. Cracking mainly occurred at the 450 °C stage with phenols, ketones, aldehydes, and sugars as the main products. The product distributions for different stages are significantly different; the selectivity of aldehydes decreased, while phenols showed an upward trend with an increase in pyrolysis temperature. Ketones and sugars reached their peak values at 450 °C. The changes in the molecular composition of each stage helped to understand the pyrolysis process. Compared with the staged pyrolysis, the direct pyrolysis process had higher selectivity of acids, aldehydes, esters, and sugars and lower selectivity of phenols, ketones, and alcohols.

Gasification versus fast pyrolysis bio-oil production: A life cycle assessment

A life cycle assessment was performed to compare the sustainability of gasification and fast pyrolysis processes for producing bio-oil using agricultural wastes from biomass. The objective was to carry out the environmental analysis associated with the production of 1 MJ bio-oil using different agricultural wastes biomasses for both thermochemical processes to determine which process is more respectful with the environment. The life cycle assessment revealed that gasification was more detrimental to the environment for all agricultural biomasses under study. In addition, greenhouse gas emissions over a 100-year time horizon were calculated, thereby demonstrating that CO2 yield emissions were higher than those for CH4 and N2O in both thermochemical processes. Furthermore, to gain a comprehensive overview, both thermochemical processes were divided into different equipment blocks to evaluate their individual impacts. Almond shell, pistachio shell and olive stone were identified as the biomasses for which minor amount of feed was needed to produce 1 MJ bio-oil. This assessment determined that the gasification stage of the gasification process and the separation stage for fast pyrolysis, were the main contributors to all mid-point impact categories. Finally, fast pyrolysis was the most environmentally friendly option for producing 1 MJ bio-oil.

Aqueous phase of thermo-catalytic reforming of sewage sludge – quantity, quality, and its electrooxidative treatment by a boron-doped diamond electrode

Pyrolysis is a promising conversion technology to produce biofuels from residues such as sewage sludge. In this study, the chemical composition and the amount of the resulting aqueous phase from the thermo-catalytic reforming process of sewage sludge at different process parameters are compared to those of non-catalytic fast pyrolysis processes from literature. Furthermore, electrooxidation using a boron-doped diamond (BDD) electrode was investigated as purification technology for the resulting aqueous phase. The results of this study show that the quantity of the aqueous phase strongly depends on the temperature of the thermo-catalytic reforming process and is presumably governed by the influence of secondary gas-carbonisate reactions like the water gas shift reaction. Higher reaction temperatures result in a reduced amount of the aqueous phase. The chemical composition of the aqueous phase of fast pyrolysis processes was comparable to that obtained at the thermo-catalytic reforming process. To reduce the chemical oxygen demand (COD) and the number of refractory substances to a level at which the aqueous phase can be discharged into a conventional wastewater treatment plant, electrooxidation experiments with the aqueous phase of the thermo-catalytic process were carried out using a BDD electrode. The treatment efficiency was investigated in galvanostatic operation varying the applied current density and the flow rate of the aqueous phase. A COD removal of 94.6% was achieved after 0.54kWh at an instantaneous current efficiency of 0.47 at a current density of 50 mA/cm2 and a flow rate of 3.7 L/min. This indicates that electrooxidation by a BDD electrode can be a promising purification technology for the aqueous phase from pyrolysis of sewage sludge. However, the high energy consumption of the process will need to be addressed in future studies to make the process economically feasible.

Conversion of Low Temperature Coal Tar into High Value-Added Chemicals Based on the Coupling Process of Fast Pyrolysis and Catalytic Cracking

Conversion of Low Temperature Coal Tar into High Value-Added Chemicals Based on the Coupling Process of Fast Pyrolysis and Catalytic Cracking

Insights into the role of CaO addition on the products distribution and sulfur transformation during simulated solar-powered pyrolysis of waste tires

Solar-powered pyrolysis of waste tires has been extensively studied because it can rapidly convert waste tires into valuable gas products using sustainable energy. However, the emitted sulfurous pollutants during this fast pyrolysis process would significantly reduce the economic feasibility of disposal waste tires. In order to investigate and regulate the sulfur transformation behavior, a large-load thermogravimetric analyzer and an optical rapid thermal processor were adopted to characterize and simulate the solar-powered fast pyrolysis behavior. The sulfur fixation effect of CaO was also evaluated in this study. Results showed that CaO addition could increase the emission of H2 and CO by promoting the cracking of organic compounds in tar. In comparison, it could decrease the CO2 emission by adsorption or transformation. Also, an excellent sulfur fixation rate in char was achieved with 10 wt% CaO addition, but accompanied by increasing emission tendency of SO2, especially at 650 °C-6000 °C/min. It was attributed to the competition reaction between H2S and SO2 in the gas phase and interaction between CaS and CaSO4 in the condensed phase. Our findings could be beneficial to develop an in-situ sulfur removal method during the pyrolysis of waste tires in the industry.

Evaluation of Analysis Methods for Formaldehyde, Acetaldehyde, and Furfural from Fast Pyrolysis Bio-oil.

Fast pyrolysis bio-oil (FPBO), a second-generation liquid bioenergy carrier, is currently entering the market. FPBO is produced from biomass through the fast pyrolysis process and contains a large number of constituents, of which a significant part is still unknown. Various analytical methods have been systematically developed and validated for FPBO in the past; however, reliable methods for characterization of acetaldehyde, formaldehyde, and furfural are still lacking. In this work, different analysis methods with (HS-GC/ECD, HPLC, UV/Vis) and without derivatization (GC/MSD, HPLC) for the characterization of these components were evaluated. Five FPBO samples were used, covering a range of biomass materials (pine wood, miscanthus, and bark), storage conditions (freezer and room temperature), and after treatments (none, filtration, and vacuum evaporation). There was no difference among the methods for the acetaldehyde analysis. A significant difference among the methods for the determination of formaldehyde and furfural was observed. Thus, more data on the accuracy of the methods are required. The precision of all methods was below 10% with the exception of the HPLC analysis of acetaldehyde with an RSD of 14%. The concentration of acetaldehyde in the FPBO produced from the three different biomasses and stored in a freezer after production ranged from 0.24 to 0.60 wt %. Storage at room temperature and vacuum evaporation both decreased significantly the acetaldehyde concentration. Furfural concentrations ranged from 0.11 to 0.36 wt % for the five samples. Storage and after treatment affected the furfural concentration but to a lesser extent than for acetaldehyde. Storage at room temperature decreased formaldehyde similarly to acetaldehyde; however, after vacuum-evaporation the concentration of formaldehyde did not change. Thus, the analysis results indicated that in FPBO the equilibrium of formaldehyde and methylene glycol is almost completely on the methylene glycol side, as in aqueous solutions. All three methods employed here actually measure the sum of free formaldehyde and methylene glycol (FAMG).

Friction and wear properties of biomass-derived oils via thermochemical conversion processes

Tribological properties of biomass-derived oils (bio-oils) were experimentally investigated, and the properties were compared with that of standard mineral oils used for lubrication purposes. Bio-oils were obtained from fast pyrolysis (using poultry and pine), gasification (“gasitar” using pine) and hydrothermal liquefaction processes (using Scenedesmus and Nannocholoropsis). The friction and wear tests were conducted using a ball on the disk tribometer test. The results showed that the coefficient of friction (COF) were around 0.02 for both gasitar and Scenedesmus bio-oil; whereas, catalytic and non-catalytic pyrolysis oils had a COF around 0.1. The wear measurements showed that catalytic fast pyrolysis bio-oils had lower wear followed by non-catalytic bio-oil and “gasitar”. Nannocholoropsis bio-oil had the highest amount of wear, and algal bio-oils showed higher wear compared to other oils. The bio-oil chemical analysis indicated that catalytic and non-catalytic fast pyrolysis bio-oil had higher oxygen content, while algal bio-oil had higher nitrogenates. Gasitar had higher hydrocarbon content with lower oxygen and nitrogenates making it a favorable lubricating oil.

Preparation and Self-Cleaning Performance of Carbon-Based Superhydrophobic Coatings Based on Non-Fluorine and Non-Toxic Corn Straw.

Recently, superhydrophobic surfaces with self-cleaning ability have attracted broad research interest due to their huge potential in daily lives and industrial applications, but the use of fluorinate, toxic organic compounds, and expensive feedstocks make superhydrophobic materials a great challenge in practical application. In this study, we present a facile dip-coating strategy to prepare superhydrophobic coatings with self-cleaning properties based on a non-fluorine and non-toxic system by using eco-friendly corn straw as raw material. During this process, aromatic carbon particles with rough hierarchical structures were prepared firstly via a simple fast pyrolysis process, followed by modification with polydimethylsiloxane (PDMS) in absolute ethanol solvent to decrease the surface free energy. Research shows these natural straw-derived carbons display a microstructure of several protrusions which is similar to the lotus leave’s and the resulted coatings exhibit an outstanding superhydrophobic property with a static water contact angle (WCA) of 151.67 ± 1.36 degrees. In addition, the as-prepared coatings possessed excellent self-cleaning performance: no contaminations were observed on the surfaces after examining with sludge, calcimine, water, and common liquids such as tea, milk, soybean milk as well as ink, which have a broad range of potential application in the field of antifouling, waterproofing, and anticorrosive.

A mechanistic investigation of lignin dimer fast pyrolysis from reactive molecular dynamics simulation

The investigation of biomass pyrolysis mechanism is crucial for the advancement of pyrolysis-based technology and it is still quite challenging due to the complex nature of lignocellulosic biomass. The application of reactive molecular dynamics simulation offers a powerful strategy to probe more essential information along the reaction process beyond advanced experimental techniques. In this work, the fast pyrolysis process of a lignin dimer, DMPD with representative β-O-4 linkage, is investigated using the ReaxFF method to explore the reaction characteristics, mechanism, and kinetics. The results elucidate that higher temperatures are favorable for the formation of CO, the transformation of guaiacol to catechol, and the breaking of bonds when varying the temperature from 1400 to 2400 K. Guaiacol achieves the highest yield of 13.37% at 2000 K while catechol and CO obtain the highest yield of 6.67% and 8.22% at 2400 K, respectively. Higher heating rates promote the generation of C5-12 products (increased from 70.59% to 78.23%) and the breaking of C-O bond regarding the investigated range of 15.5–170 K/ps. Based upon the time evolution of the reactant and final product distribution under various operating conditions, a first-order kinetic model is derived to calculate the activation energies of C-C, C-H, C-⎔O bonds, and DMPD to be 122.41, 35.18, 52.58, and 52.18 kJ/mol, respectively. A reaction pathway is proposed from the product distribution along the DMPD pyrolysis at 2000 K. The detailed characteristics from ReaxFF simulations enable a better understanding of the complicated pyrolysis mechanism of biomass from a molecular level.

Porosity roles of micro-mesostructured ZSM-5 in catalytic fast pyrolysis of cellulolytic enzyme lignin for aromatics

Cellulolytic enzyme lignin could be utilized to produce aromatic-rich bio-oil in the catalytic fast pyrolysis (CFP) process, in which strong-acidic ZSM-5 is often used as the catalyst. The introduction of mesopores into conventional ZSM-5 catalysts can improve the diffusion of heavy components and thus enable the modulation of pyrolysis products. To investigate the effect of mesoporous structure parameters on the diffusion of heavy phenols and the regulation of pyrolysis products by different types of pore structures, three different mesoporous ZSM-5 were prepared (core-shell, hierarchical, composites), with textural properties being compared in detail. The structural parameters were adopted to analyze the relationship between mesopores distribution and catalytic performance, revealing the significant effect of equivalent mesopore size. Among the prepared catalysts, a micro-mesostructured composite zeolite (ZMA) with internal hierarchical pores and ununiform mesolayer shell had a suitable mesostructure, of which the interconnected meso-channels improved the accessibility of inner acidic sites. Also, it was optimum to balance aromatic yield (above 7.5 wt%) and the product distribution (MAHs/PAHs approaching 6), revealing that its moderate equivalent pore size maintained a certain shape-selectivity to suppress PAHs formation. It was further shown that the applicable catalyst to lignin ratio (C/L) ranges differed with various mesostructures, as ZMA and hierarchical samples were suitable for higher and lower ratios, respectively.

Integrated Process of Coal Fast Pyrolysis in a Fluidized Bed Reactor With Reforming Reaction of Simulated Fuel Gas to Promote Light Tar Evolution

The evolution behavior of the light tar during coal fast pyrolysis under inert gas, simulated fuel gas (SFG) atmosphere, and catalytic reformation of simulated (CRS) fuel gas over Ni/Al2O3 was studied in this article. The light tar was recovered from the distillation of the crude tar at the temperature of 300°C and subsequently subjected to detection through the GC-MS analysis. It was found that both SFG and CRS over Ni/Al2O3 significantly enhanced the light tar yield, but a little effect was shown on the heavy tar yield. According to the molecular structure characteristics, the compounds in the light tar could be classified into several groups: aromatic components, phenol components, aliphatic components, heteroatom components, and O-containing components (phenol compounds excluded). It was demonstrated that the selectivity of each component in the light tar varied significantly with the pyrolysis atmosphere and temperature. The evolution of the aromatic components took the dominant role in the light tar produced at high temperature. The SFG and CRS contributed markedly to enhancing the evolution of the O-aromatic components in the light tar, whereas they suppressed the evolution of the O-aliphatic components and the phenol components in the light tar at high temperature.

Comparative study on the one‐step and two‐step pyrolysis of lignocellulosic biomass: Effects of two‐step pyrolysis on improving product quality

Two-step pyrolysis (TSP) and one-step pyrolysis (OSP) of rice husk was conducted using a fixed-bed reactor, and the product distribution and physicochemical property were analyzed. TSP had two fast pyrolysis processes, which were, respectively, set at lower temperature (400°C) in the first step and high temperature (550°C) in the second step, while OSP was only set at high temperature (550°C). Compared with OSP, TSP increased the total yields of char and gas but decreased the total yield of bio-oil. The pyrolysis process of the first step facilitated the cross-linking and polycondensation reactions in the char of the first step, thus inhibiting the decomposition of the char from the first step and decreasing the yield of bio-oil in the second step. Due to the high pyrolysis temperature, there was no significant difference between the char from the second step and the char from OSP. The first step improved the selectivity of acids, furans and phenols with complex side chains in bio-oil. The bio-oil from the second step had lower acidity, and higher selectivity of phenols and hydrocarbons. Compared with the gas product of OSP, the H2 and CH4 contents of the gas product from the second step were improved by more than 70% and 35%. TSP could not only improve the selectivity of value-added chemicals but also achieve the higher quality of gas and bio-oil as fuel.

Effect of torrefaction pretreatment on the fast pyrolysis behavior of biomass: Product distribution and kinetic analysis on spruce-pin-fir sawdust

Torrefaction pretreatment is of great significance to the enhancements of biomass characteristics. Product distribution and kinetics analysis of spruce-pin-fir (SPF) sawdust and its torrefaction samples were studied during the fast pyrolysis process. Under anaerobic conditions, torrefied biomass was prepared at different temperatures in a slot-rectangular spouted bed reactor. Fast pyrolysis experiments were conducted in a tube furnace with online mass spectrometry. The effects of torrefaction degree and pyrolysis temperature on product distribution were discussed. The main gaseous products, ie. CO, CO2, H2, and CH4, were investigated, and kinetic data of gaseous product formation was solved based on the isoconversional method. Other volatiles were the main product during the fast pyrolysis process, and the char yield was the lowest. With the increase of torrefaction degrees, the yield of char increased from 19.80 % to 22.09 % at 800 °C. The pyrolysis gas yield decreased from 25.78 % to 17.18 % as the torrefaction temperature increased from 240 °C to 300 °C. The gaseous products were mainly CO and CO2. The content of CO tended to increase, and the content of CO2 decreased when the pyrolysis temperature increased. The order of activation energy was E (CO2)>E (H2) >E (CO) >E (CH4) during the fast pyrolysis of SPF. The activation energy of the CO2, CH4, and H2 increased with the increase of the torrefaction temperature. According to different evaluation indexes, the optimal setting of reaction conditions is determined.

Optimization of Pyrolysis Temperature and Particle Size on the Phenols and Hemicellulose Fast Pyrolysis Products in a Tandem Micro-Pyrolyzer

Fast pyrolysis of sugarcane bagasse was investigated in a tandem micro-pyrolyzer. The effects of temperature and particle size on the phenolic compounds and hemicellulose products distribution were examined during fast pyrolysis process. For this, changes in the micro-reactor parameters were made (particle size between 0.1 and 0.5 mm and reactor temperature between 450 and 600 °C). Response Surface Methodology (RSM) was used to optimize pyrolysis parameters. The results indicated that the temperature had the highest effect on phenolic and furfural-type compounds, whereas the particle size did not exhibit significant effects on carboxylic acid products. The largest number of phenolic compounds were achieved upon decreasing the temperature and increasing particle size. The ANOVA analysis revealed that the full quadratic model was more adequate for phenolic and furfural compounds, whereas the linear square model was accurate for carboxylic acids. In general, a tandem micro-pyrolyzer interfacing with a GC-MS analysis facilitated a better understanding of a chemical composition of biomass and therefore, could remarkably improve the valorising of sugarcane bagasse application in biorefinery processes.