Wood Fast Pyrolysis Research Articles

Fast co-pyrolysis of wood and plastic: Evaluation of the primary gaseous products

Bio-oil derived from fast pyrolysis of wood contains oxygenates and has a relatively low heating value. These are challenges that need to be tackled if wood-derived bio-oil is to be used as drop-in fuels. The bio-oil can be obtained by condensation of gaseous products. Using a material with no oxygen in addition to wood during fast pyrolysis could be a technique to reduce the formation of oxygenates and promote a hydrocarbon-rich product. This work aims to evaluate the primary gaseous products formed during fast co-pyrolysis of birch wood and plastic. The pyrolysis was performed in a micropyrolyser at 600 °C with a residence time of 5 s. Birch wood and plastic were melt-mixed at different weight ratios to study possible interaction effects upon pyrolysis. The different plastics used were low-density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS). The total gaseous product was between 10–20 wt% from Wood-LDPE or Wood-PP, while it was in the range 15–90 wt% from Wood-PS. The analysis of gas product found that the formation of oxygenates (up to 9 wt%) was lower than expected (up to 14 wt%) for the mixtures of wood and plastic compared to the pure materials (about 18 wt%). The reduction of oxygenates (up to 90 %) was mainly due to a lower production of ketones, carboxylic acids and aldehydes. Maximum hydrocarbons in the gas phase from binary mixtures were around 8, 15 and 55 wt% from Wood-LDPE, Wood-PP and Wood-PS, respectively. The most significant difference between experimental and estimated values assuming no interaction among hydrocarbons was observed in the case of alkenes and alkanes for Wood-LDPE, as well as alkanes for Wood-PS, while the Wood and PP mixture showed almost no signs of interaction. This work is beneficial for understanding interactions between wood and plastics, and could be used to reduce the amount of oxygenates from wood pyrolysis and reduce the need for upgrading.

Solid‐Phase Extraction of the Aromatic By‐Products Obtained by Fast Pyrolysis of Pretreated Lignocellulose

AbstractPyrolysis is a recognized technology for lignocellulose conversion into bio‐based fuels, materials, and chemicals. In this work, pyrolysis liquids were obtained by fast pyrolysis of wood after pretreatment with diluted sulfuric acid. The pyrolysis liquids were separated by solid‐phase extraction with an anion exchange resin Lewatit VPOC 1074 as the stationary phase. The aromatic constituents of the pyrolysis liquids were adsorbed on the resin, while the sugar derivative fraction was eluted with water. Different desorption solvents were tested for batch and continuous elution of phenol derivatives. Most promising results were obtained for selective separation of phenol carboxylic acids by changing the ratio of water, methanol, and acetic acid in the solid‐phase extraction solvent system.

Synthesis gas and H2 production by chemical looping reforming using bio-oil from fast pyrolysis of wood as raw material

• CLR of pine wood bio-oil has been demonstrated in a 1 kW th continuous unit. • Complete conversion of bio-oil was found during 60 h of operation. • Carbon deposition can be minimized and controlled in the continuous CLR unit. • Maximum H 2 production and H 2 /CO ratio were found at 650 °C with very low C deposition. • Auto-thermal H 2 production at 650 °C was 13.6 g/100 g of bio-oil with H 2 O/bio-oil = 6. The interest of using bio-oil produced by biomass fast pyrolysis to generate H 2 and high value chemicals is growing up in order to reduce CO 2 emissions by the use of biomass. In the present work, bio-oil Chemical Looping Reforming was demonstrated in a 1 kW th continuous unit during 60 h of operation using a Ni-based oxygen carrier to produce syngas/H 2 . No agglomeration of the oxygen carrier was detected. Complete conversion of the bio-oil was obtained in all cases, obtaining as main products H 2 , CO, CO 2 and in much lower concentration CH 4 . Carbon deposition in the bed appeared in almost all the experiments carried out during the bio-oil reforming, and CO 2 was found in the air reactor outlet, although did not affect to the process performance when oxygen carriers were used. This fact only let to a reduction of the CO 2 capture efficiency. Fuel reactor temperature was a key factor for the H 2 production, the H 2 /CO ratio and the carbon accumulated in the CLR unit. The maximum H 2 production together with the maximum H 2 /CO ratio of 6 were found at the lowest temperature used, 650 °C. In addition, the carbon formed in the fuel reactor was reactive enough so that it could be burnt in the air reactor with minimum accumulation in the continuous unit. The autothermal H 2 production was 13.6 g/100 g of bio-oil without water at 650 °C with a H 2 O/bio-oil = 6, which corresponds to 68 mol H 2 /kg of bio-oil without water. Therefore, the CLR process of bio-oil allows obtaining high H 2 production with low carbon deposition at 650 °C using less amount of water than in conventional bio-oil reforming.

Combined organic acid leaching and torrefaction as pine wood pretreatment before fast pyrolysis

Reducing pine wood particle size is beneficial for acid leaching (shorter leaching time, smaller equipment size) and also for pyrolysis (low pyrolysis time, high oil and sugar yields). Torrefaction helps to improve the energy efficiency of grinding. However, it is not well established whether alkali and alkaline earth metals can still be removed effectively, after torrefaction, by leaching with an acetic acid solution, while keeping high oil and sugar yields. To investigate this, an experimental study was carried out combining torrefaction (290?C, 20 minutes) and subsequently acid leaching of pine wood as pretreatment step before fast pyrolysis of the feedstock at 530?C. The oil, char, gas, water, pyrolytic lignin, light oxygenates and levoglucosan yields were compared with the results obtained from fast pyrolysis of untreated pine wood and acid leached pine wood at 530?C. In addition, pyrolysis vapors were condensed step-wise into two distinguished fractions (condensation T = 80?C) to increase the levoglucosan concentration up to 45 wt.% with or without applying torrefaction as pretreatment. Intra-particle reactions during torrefaction are more profound in the presence of alkali and alkaline earth metals. Cellulose and lignin derived products (e.g. levolucosan (~0.2 kg/kg pine wood) and pyrolytic lignin (~0.11 kg/kg pine wood) were not affected by the torrefaction pre-treatment of acid leached pine wood. In general, torrefaction of acid leached pine wood followed by fast pyrolysis showed similar total organics, char, gas, light oxygenates and produced water yields compared to fast pyrolysis of acid leached pine wood. Contrary, when acid leaching is applied after torrefaction the organics (dry bio-oil) and light oxygenates yields are quite comparable to the results of untreated pine wood fast pyrolysis.

Synthesis and Regeneration of Nickel-Based Catalysts for Hydrodeoxygenation of Beech Wood Fast Pyrolysis Bio-Oil

Four nickel-based catalysts are synthesized by wet impregnation and evaluated for the hydrotreatment/hydrodeoxygenation of beech wood fast-pyrolysis bio-oil. Parameters such as elemental analysis, pH value, and water content, as well as the heating value of the upgraded bio-oils are considered for the evaluation of the catalysts’ activity and catalyst reuse in cycles of hydrodeoxygenation after regeneration. The reduction temperature, selectivity and hydrogen consumption are distinct among them, although all catalysts tested produce upgraded bio-oils with reduced oxygen concentration, lower water content and higher energy density. Ni/SiO2, in particular, can remove more than 50% of the oxygen content and reduce the water content by more than 80%, with low coke and gas formation. The evaluation over four consecutive hydrotreatment reactions and catalyst regeneration shows a slightly reduced hydrodeoxygenation activity of Ni/SiO2, mainly due to deactivation caused by sintering and adsorption of poisoning substances, such as sulfur. Following the fourth catalyst reuse, the upgraded bio-oil shows 43% less oxygen in comparison to the feedstock and properties comparable to the upgraded bio-oil obtained with the fresh catalyst. Hence, nickel-based catalysts are promising for improving hardwood fast-pyrolysis bio-oil properties, especially monometallic nickel catalysts supported on silica.

Simultaneous production of gaseous and liquid biofuels from the synergetic co-valorisation of bio-oil and crude glycerol in supercritical water

This work addresses the co-valorisation in supercritical water of bio-oil obtained from the fast pyrolysis of wood and crude glycerol yielded as a by-product during biodiesel production. The experiments were conducted at 380 °C and 230 bar for 30 min with a Ni-Co/Al-Mg catalyst, analysing the effects on the process of the catalyst loading (0–0.25 g catalyst/g organics) and feed composition (each material alone and all possible binary mixtures). The yields to gas, upgraded bio-oil (liquid) and solid varied as follows: 4–87%, 0–46% and 0–18%, respectively. A synergistic interaction between crude glycerol and bio-oil took place during the upgrading process, which allowed the complete and simultaneous transformation of both materials into gas and liquid bio-fuels with a negligible solid formation. The compositions of the gas and the upgraded liquid can be easy tailored by adjusting the catalyst amount and the composition of the feed. The gas phase was made up of H2 (7–49 vol.%), CO2 (31–56 vol.), CO (0–7 vol.%) and CH4 (6–57 vol.%) and had a Lower Heating Value (LHV) ranging from 8 to 22 MJ/m3 STP. The upgraded bio-oil consisted of a mixture of carboxylic acids (0–73%), furans (0–7%), phenols (0–85%), ketones (0–22%) and cyclic compounds (0–53%). The proportions of C, H and O in the liquid shifted between 66–77 wt.%, 7–11 wt.% and 15–25 wt.%, respectively, while its Higher Heating Value (HHV) ranged from 29 to 34 MJ/kg. An optimum for the simultaneous production of gas and liquid bio-fuels was achieved with a solution having equal amounts of each material and employing a catalyst amount of 0.25 g catalyst/g organics. Under such conditions, 37% of the bio-oil was transformed into an upgraded liquid having a HHV (32 MJ/kg) two times higher than the original material (16 MJ/kg) with a negligible solid formation; the rest of the bio-oil and all the crude glycerol being converted into a rich CH4 (55 vol.%) biogas with a high LHV (21 MJ/m3 STP). This represents a step-change in future energy production and can help to establish the basis for a more efficient and sustainable biomass valorisation.

Modification of bitumen binder by the liquid products of wood fast pyrolysis

The physical and chemical properties of fast pyrolysis products and the composite binder were studied. Samples of the composite binder with additions of pyrolysis oil (PO) and pyrolytic lignin (PL) were obtained, and their properties were investigated. The results from binder analysis show that PO can be used as a component for the road binder in content up to 1%; and PL in content up to 10%. A significant reproducible volume increase was detected at a temperature range of 100–140°C in the composite binder with PL compared to initial binder. The volume increase can decrease binder consumption by 4 times. Samples of asphalt concrete made with the composite binder were obtained, their properties were studied. The results from asphalt concrete analysis show that PL can be used in content up to 5%.

Application of orbitrap mass spectrometry for analysis of model bio-oil compounds and fast pyrolysis bio-oils from different biomass sources

Pyrolysis bio-oils have great potential for the future use as biofuels and source of oxygenated chemicals. To optimize a pyrolysis process, detailed knowledge about the chemical composition of bio-oils is necessary. In recent years, high-resolution mass spectrometry (HRMS) has successfully been used to the characterization of pyrolysis bio-oils from lignocellulosic biomass. This method enabled to detect thousands of semivolatile and nonvolatile, high-molecular-weight bio-oil compounds and provided partial information about their structure. In this work, we used high-resolution orbitrap mass spectrometry to characterize semivolatile and nonvolatile, high-molecular-weight compounds of four bio-oils obtained from the ablative flash pyrolysis of different biomass sources. Before the analyses of these bio-oils, we analyzed model bio-oil compounds and commercially available bio-oil from fast pyrolysis of wood using positive-ion and negative-ion electrospray (ESI) and positive-ion and negative-ion atmospheric pressure chemical ionization (APCI) orbitrap mass spectrometry and compared the results. Based on this comparison, a combination of negative-ion ESI and APCI was found to be well suited for the characterization of pyrolysis bio-oils; these techniques were thus used for the study of bio-oils from different biomass sources and the obtained results were compared. In the studied bio-oils, mostly compounds with 1–8 oxygen atoms per molecule were detected and their degree of unsaturation (DBE) was about 1–10 (negative-ion ESI) and 1–17 (negative-ion APCI), respectively. Among the studied bio-oils, the differences were observed mostly in abundances of their major compounds (compound classes). The analyses of model bio-oil compounds brought valuable information about their behavior during the HRMS characterization of bio-oils. The presented results could help to improve the understanding of bio-oil composition and HRMS characterization of bio-oils and facilitate their further utilization.

Techno-economic analysis of biofuel production via bio-oil zeolite upgrading: An evaluation of two catalyst regeneration systems

Biofuels have been identified as a mid-term greenhouse gas (GHG) emissions abatement solution for decarbonising the transport sector. This study examines the techno-economic analysis of biofuel production via biomass fast pyrolysis and subsequent bio-oil upgrading via zeolite cracking. The aim of this study is to compare the techno-economic feasibility of two conceptual catalyst regeneration configurations for the zeolite cracking process: (i) a two-stage regenerator operating sequentially in partial and complete combustion modes (P-2RG) and (ii) a single stage regenerator operating in complete combustion mode coupled with a catalyst cooler (P-1RGC). The designs were implemented in Aspen Plus® based on a hypothetical 72 t/day pine wood fast pyrolysis and zeolite cracking plant and compared in terms of energy efficiency and profitability. The energy efficiencies of P-2RG and P-1RGC were estimated at 54% and 52%, respectively with corresponding minimum fuel selling prices (MFSPs) of £7.48/GGE and £7.20/GGE. Sensitivity analysis revealed that the MFSPs of both designs are mainly sensitive to variations in fuel yield, operating cost and income tax. Furthermore, uncertainty analysis indicated that the likely range of the MFSPs of P-1RGC (£5.81/GGE − £11.63/GGE) at 95% probability was more economically favourable compared with P-2RG, along with a penalty of 2% reduction in energy efficiency. The results provide evidence to support the economic viability of biofuel production via zeolite cracking of pyrolysis-derived bio-oil.

Atmospheric Hydrodeoxygenation of Biomass Fast Pyrolysis Vapor by MoO3

MoO3 has been tested as a catalyst in hydrodeoxygenation (HDO) of both model compounds (acetone and guaiacol) and real biomass pyrolysis vapors under atmospheric pressure. The pyrolysis vapor was obtained by fast pyrolysis of wood or lignin in a continuous fast pyrolysis reactor at a fixed temperature of 500 °C, and it subsequently passed through a downstream, close coupled, fixed bed reactor containing the MoO3 catalyst. The influences of the catalyst temperature and the concentration of H2 on the HDO of the pyrolysis vapors were investigated. The level of HDO of the biomass pyrolysis vapors was not significant at temperatures below 400 °C. At 450 °C catalyst temperature and 93 vol % H2 concentration, the wood pyrolysis vapor was more active toward cracking forming gas species instead of performing the desired HDO forming hydrocarbons. The lignin pyrolysis vapor was more resistant to cracking and yielded 16.2 wt %daf organic liquid, while achieving 52% degree of deoxygenation at 450 °C catalyst temperatu...

A study of the properties of a composite asphalt binder using liquid products of wood fast pyrolysis

The results of a study of the adhesive properties of a composite asphalt binder modified with pyrolytic lignin—a water-insoluble fraction of liquid products of fast pyrolysis of wood—are presented. It is shown that 10 wt % pyrolytic lignin increases the adhesive strength of the composite asphalt binder and the obtained samples of modified asphalt concrete correspond to the requirements of GOST (State Standard) 9128–84.

Effect of fast pyrolysis conditions on biomass solid residues at high temperatures

Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000–1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103°C/s, 104°C/s) on the char yield and morphology. Scanning electron microscopy (SEM), elemental analysis, and ash compositional analysis were applied to characterize the effect of operational conditions on the solid residues (char, soot) and gaseous products. The char yield from fast pyrolysis in the DTF setup was 3 to 7% (daf) points lower than in the WMR. During fast pyrolysis pinewood underwent drastic morphological transformations, whereas beechwood and straw samples retained the original porous structure of the parental fuel with slight melting on the surface. The particle size of Danish wheat straw char decreased in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due to differences in the content of lignin and resin acids.

Application of the water-insoluble pyrolysis oil fraction as an organic binder

Wood fast pyrolysis oil could potentially be applied as an additive to an organic binder for use in road construction. The aim of this work was to investigate the properties of a composite binder made of bitumen and the water-insoluble fraction of wood pyrolysis oil. Pyrolysis oil was made from birch wood by fast ablative pyrolysis. Separation of the pyrolysis oil was conducted with recovery of the water-insoluble fraction of wood pyrolysis oil. A composite binder consisting of bitumen and the water-insoluble fraction of pyrolysis oil was produced. Modified asphalt concrete was made with the composite binder. The properties of the composite binder and the modified asphalt concrete were investigated. It can be concluded that the water-insoluble fraction of pyrolysis oil can be used as a component of composite bitumen binder. The best properties are exhibited by the binder supplemented with 10–15% of the water-insoluble fraction of pyrolysis oil.

Formation of nascent char structure during the fast pyrolysis of mallee wood and low-rank coals

The structural evolution of nascent chars during the fast pyrolysis of a wood and two low-rank coals was investigated in this study. Western Australian Collie sub-bituminous coal, Victorian Loy Yang brown coal and Western Australian mallee wood were pyrolysed in a wire-mesh reactor that is capable of providing rapid heating rates (up to 5000Ks−1) and accurate holding time (in increments of 10ms) at peak temperature. FT-Raman spectroscopy was used to characterise the key structural features of raw fuels and nascent chars. The combined use of a wire-mesh reactor and a FT-Raman spectroscopy has given insights into the structural transformation from coal/biomass to nascent chars. There were insignificant changes in the aromatic ring systems of two coals during the initial fast heating from room temperature to 600°C. During holding at 600°C, the changes that occurred in ring systems for the three fuels were different. Mallee wood and Loy Yang coal underwent more changes than Collie coal. In addition, mallee wood had ring condensation during holding at 600°C up to 30s. However, little growth in large aromatic rings of two coals was observed during holding at 600°C up to 50s.

Sorptive removal of salicylic acid and ibuprofen from aqueous solutions using pine wood fast pyrolysis biochar

Pine wood biochar, prepared at 698K with a residence time of 20–30s in an auger-fed reactor, was used as a 3-dimensional adsorbent to remove salicylic acid and ibuprofen from aqueous solutions. This biochar was characterized by FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, surface area determination, and zero point charge measurements. Batch sorption studies were carried out at pH values from 2 to 10, adsorbate concentrations from 25 to 100mg/L and temperatures from 298 to 318K. The adsorption of both adsorbates was highest at low pH values, dropped as pH increased and then exhibited a second increase related to the pKa of these carboxylic acid adsorbates. This was followed by a further drop at high pH. Conjugate acid/base equilibria of the adsorbates and the phenolic hydroxyl and carboxylic acid biochar sites versus pH dominated the mechanism. Sorption followed pseudo-second order kinetics. Sorption was evaluated from 298 to 318K using the Freundlich, Langmuir, Redlich–Peterson, Toth, Sips, and Radke–Prausnitz adsorption isotherm models. Langmuir adsorption capacities for both salicylic acid and ibuprofen were 22.70 and 10.74mg/g, respectively. This low surface area pinewood biochar (1.35m2/g) can adsorb far more adsorbate compared to commercial activated carbons per unit of measured surface area. Methanol stripping achieved 93% and 88% desorption of salicylic acid and ibuprofen, respectively, from the spent biochar, and 76% and 72% of the initial salicylic acid and ibuprofen adsorption capacity, respectively, remained after four full capacity equilibrium recycles.

Techno-economic performance analysis of biofuel production and miniature electric power generation from biomass fast pyrolysis and bio-oil upgrading

The techno-economic performance analysis of biofuel production and electric power generation from biomass fast pyrolysis and bio-oil hydroprocessing is explored through process simulation. In this work, a process model of 72 MT/day pine wood fast pyrolysis and bio-oil hydroprocessing plant was developed with rate based chemical reactions using Aspen Plus® process simulator. It was observed from simulation results that 1kgs−1 pine wooddb generate 0.64kgs−1 bio-oil, 0.22kgs−1 gas and 0.14kgs−1 char. Simulation results also show that the energy required for drying and fast pyrolysis operations can be provided from the combustion of pyrolysis by-products, mainly, char and non-condensable gas with sufficient residual energy for miniature electric power generation. The intermediate bio-oil product from the fast pyrolysis process is upgraded into gasoline and diesel via a two-stage hydrotreating process, which was implemented by a pseudo-first order reaction of lumped bio-oil species followed by the hydrocracking process in this work. Simulation results indicate that about 0.24kgs−1 of gasoline and diesel range products and 96W of electric power can be produced from 1kgs−1 pine wooddb. The effect of initial biomass moisture content on the amount of electric power generated and the effect of biomass feed composition on product yields were also reported in this study. Aspen Process Economic Analyser® was used for equipment sizing and cost estimation for an nth plant and the product value was estimated from discounted cash flow analysis assuming the plant operates for 20years at a 10% annual discount rate. Economic analysis indicates that the plant will require £16.6 million of capital investment and product value is estimated at £6.25/GGE. Furthermore, the effect of key process and economic parameters on product value and the impact of electric power generation equipment on capital cost and energy efficiency were also discussed in this study.

Valorisation of bio-oil resulting from fast pyrolysis of wood

AbstractBio-oil resulting from the pyrolysis of lignocellulose is a complex mixture of polar low molecular mass oxygenated compounds of various functionalities and non-polar high molecular mass lignin derivatives. Several approaches to the upgrading of bio-oil are currently in progress. This study investigates the valorisation of crude bio-oil using physical and chemical methods. The effects of methanol addition on some properties of the bio-oil are investigated. Stable bio-oil/diesel oil emulsions are produced by the addition of surfactants with a hydrophilic-lipophilic balance value of 5–6. An alternative approach towards the upgrading of bio-oil is the hydrotreatment of the water-soluble fraction of bio-oil. Two-stage hydroprocessing with noble-metal catalysts Ru/C and Pt/C increases the intrinsic hydrogen content of the water-soluble fraction. The results show that the thermally unstable components including sugars, ketones and aldehydes are readily converted to diols and alcohols at pressures of 5 MPa. These observations can be explained by a set of reaction pathways for the compounds identified.

Comparison for the compositions of fast and slow pyrolysis oils by NMR characterization

The pyrolysis of softwood (SW) kraft lignin and pine wood in different pyrolysis systems were examined at 400, 500 and 600 °C. NMR including quantitative (13)C and Heteronuclear Single-Quantum Correlation (HSQC)-NMR, and Gel Permeation Chromatography (GPC) were used to characterize various pyrolysis oils. The content of methoxyl groups decreased by 76% for pine wood and 70% for lignin when using fast pyrolysis system. The carbonyl groups also decreased by 76% and nearly completely eliminated in 600 °C pine wood fast pyrolysis oil. Compared to the slow pyrolysis process, fast pyrolysis process was found to improve the cleavage of methoxyl groups, aliphatic CC bonds and carbonyl groups and produce more polyaromatic hydrocarbons (PAH) from lignin and aliphatic CO bonds from carbohydrates. Another remarkable difference between fast and slow pyrolysis oils was the molecular weight of fast pyrolysis oils increased by 85-112% for pine wood and 104-112% for lignin.

Energetic and environmental performance of three biomass upgrading processes integrated with a CHP plant

In order to react on future expected increased competition on restricted biomass resources, communal combined heat and power (CHP) plants can be integrated with biomass upgrading processes that add valuable products to the portfolio. In this paper, outgoing from a base case, the retrofit integration of production of wood pellets (WPs), torrefied wood pellets (TWPs) and wood fast pyrolysis slurry (PS) with an existing wood-fired CHP plant was simulated. Within the integration concept, free boiler capacity during times of low district heat demands is used to provide energy for the upgrading processes. By detailed part-load modelling, critical process parameters are discussed. With help of a multiperiod model of the heat duration curve, the work further shows the influence of the integration on plant operating hours, electricity production and biomass throughput. Environmental and energetic performance is assessed according to European standard EN 15603 and compared to the base case as well as to stand-alone production in two separate units.The work shows that all three integration options are well possible within the operational limits of the CHP plant. Summarising, this work shows that integration of WP, TWP and PS production from biomass with a CHP plant by increasing the yearly boiler workload leads to improved primary energy efficiency, reduced CO2 emissions, and, when compared to stand-alone production, also to substantial fuel savings.

Effect of particle size and temperature on woody biomass fast pyrolysis at high temperature (1000–1400°C)

Fast pyrolysis of wood was conducted in a drop tube furnace to study the influence of temperature (1000–1200–1400°C) and particle size (0.35–0.80mm) for a particle residence time of some seconds. No effect of particle size has been observed on final pyrolysis products. At 1000°C, much more gas and tar are produced than char (yield of 96% versus 4%); hydrocarbons, including light species and tar, present a considerable yield of 26%. From 1200°C, the drastic hydrocarbons decomposition, emphasized with temperature, leads to high yields in soot, H2 and CO. At 1200°C, no tar are detected; at 1400°C only low amounts of CH4 and C2H2 still remain. Under the explored conditions, char and soot gasification with H2O and CO2, species produced during pyrolysis, is kinetically blocked. However, even if carbonaceous solids do not seem to be considerably affected by gasification, they suffer some changes when temperature is increased.