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# FLASH PYROLYSIS OF ASPEN-POPLAR WOOD.

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## Abstract

In the reported experiments, a continuous fluidized bed bench scale flash pyrolysis unit operating at atmospheric pressure and feed rates of about 15 g/h has been successfully designed and operated. A unique solids feeder capable of delivering constant low rates of biomass has been developed. Extensive pyrolysis tests with hybrid aspen-poplar sawdust (105-250 mu m) have been carried out to investigate the effects of temperature, particle size, pyrolysis atmosphere and wood pretreatment on yields of tar, organic liquids, gases and char. At optimum pyrolysis conditions high tar yields of up to 65% of the dry wood weight fuel are possible at residence times of less than one second. Refs.

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... It results in the formation of a great variety of chemical species usually divided into three categories: a stable mixture of synthesis gas, a liquid resulting from condensation of the condensable organic compound (tar), and a solid residue rich in carbon (char). The former is mainly composed of CO, CO 2 , H 2 and light hydrocarbons, while the main components of tar are heavy hydrocarbons (C x H y ) [1][2][3][4]. Pyrolysis process is governed by many parameters among which the most important are pressure, residence time of the fuel within the reactor, and operative temperature. In particular, the latter significantly influences the concentration of products involved. ...
... A pre-exponential factor (s À1 ) C 2 inertitial resistance factor (m À1 ) ...
... Production rates are greatly influenced by the operative conditions, especially by temperature. Char and tar yields are predominant at low temperature processes; on the other hand, when the operative temperature increases, the main products are light gases [1,2,13]. Indeed, at high temperature (i.e., greater than 873 K) the activation of tar cracking reactions leads to an increase of gas production reducing the tar yields, whereas char amount is almost constant at temperature higher than 773 K. ...
... Compared to the fixed bed reactors, the fluidized bed reactor is determined to be one of the promising technologies for biomass thermal conversion due to the high-efficient heat transfer and ease of scale-up, which has potential for commercial practice (Garcia, et al. 1995;Islam, et al. 1999;Mohan, et al. 2006;Park, et al. 2008;Zheng, et al. 2008). (Scott and Piskorz 1982;Scott and Piskorz 1984;Piskorz, et al. 1986;Piskorz, et al. 1988;Piskorz, et al. 1989;Radlein, et al. 1991;Piskorz, et al. 2000). A bench scale atmospheric pressure fluidized bed unit using sand as the fluidized solid with the feeding rate of 30 g/h of biomass was designed to investigate the yield of liquid product at different temperatures in an inert nitrogen atmosphere with an apparent vapor residence time of approximately 0.5 s (Scott and Piskorz 1982). ...
... (Scott and Piskorz 1982;Scott and Piskorz 1984;Piskorz, et al. 1986;Piskorz, et al. 1988;Piskorz, et al. 1989;Radlein, et al. 1991;Piskorz, et al. 2000). A bench scale atmospheric pressure fluidized bed unit using sand as the fluidized solid with the feeding rate of 30 g/h of biomass was designed to investigate the yield of liquid product at different temperatures in an inert nitrogen atmosphere with an apparent vapor residence time of approximately 0.5 s (Scott and Piskorz 1982). Piskorz (Piskorz, et al. 1986) reported the pyrolytic behavior of the two types of cellulose (S&S powdered cellulose with ash content of 0.22% and Baker TLC microcrystalline cellulose with ash content of 0.04%) in the fluidized bed reactor, giving the distribution of the gas, liquid and solid products at the temperature from 450 to 550 o C summarized in Table 2-3. ...
... However, the condensing method, termed as direct condensing and indirect condensing, is another important factor to influence the distribution of the products. Direct condensing (such as quenching) is defined as the direct mixing of the cold cooling-agent and the hot vapor, giving the efficient heat exchange and precipitation (Scott and Piskorz 1982;Scott and Piskorz 1984;Piskorz, et al. 1986;Bridgwater 2008). The challenge is the selection of the cooling-agent which should be of large specific capacity and insoluble with the constituents in bio-oil. ...
Article
The global demand of the volume of woody biomass (such as wood, logging residue, sawdust and so on) is huge and increased annually, due to its new application for the energy/fuel production during recent years. Pyrolysis is termed as a promising thermo-chemical technology to convert woody biomass to liquid, gas and solid fuels/chemicals. The better understanding of the pyrolysis mechanism of woody biomass is demanding considering the thermal performance of individual components (hemicellulose, cellulose and lignin) and their interactions. In order to develop the current understanding of the pyrolysis of the individual components (hemicellulose, cellulose and lignin) in woody biomass and fill the knowledge gap on their interactions under pyrolytic conditions, the on-line pyrolysis and off-line pyrolysis study of the model compounds of the components and their “synthesized biomass” samples has been extensively investigated employing TGA-FTIR and fast pyrolysis unit, in terms of the mass loss variation against temperature together with the on-line identification of the evolved volatiles by FTIR, yield of pyrolyzed products (gas, bio-oil and char) from the fast pyrolysis unit, variation of the compositions in bio-oil and gas products against the fluidized-bed-reactor temperature, the chemical pathways for the chemical structure change of the macromolecules and the cracking of the primary fragments, and the interactions among the chemical components. The proposed chemical pathways, indicating the possible competitive and/or consecutive relationship among the prominent compounds in bio-oil and gaseous product, give hints to improve the current kinetic scheme of the individual components. Notably, the vapor-phase interaction among the components in the fluidized-bed reactor is investigated in terms of the product yield and variation of the prominent compounds in bio-oil and gaseous product, but their interactions in solid/liquid phase are not involved.
... % for 530C, because the associated kinetic parameters also gave reasonably accurate predictions at the other test temperatures. The For whole poplar, the simulated yields of organic liquids, GHCs, H 2 , and CO are accurate across the entire temperature range, and the flaws in the [5][6][7]. ...
... A somewhat broader range of biomass composition was tested in a lab-scale fluidized bed [5][6][7], although this dataset has breaches in the mass and elemental balances that are considerably worse than those from the pilot-scale fluidized bed. As seen in Fig. 2, the simulated organic liquids yields are within the measurement uncertainties across their test temperature ranges, except for the hottest temperature with poplar wood and the coolest temperature with red maple. ...
... For the pilot-scale testing [4], one set interpreted poplar and maple woods and another interpreted whole poplar waste and wheat straw. For [5][6][7], the frequency factors to produce CO and oils had to be varied for both components in almost every sample. ...
Conference Paper
Full-text available
Biomass pyrolysis technologies often process an assortment of biomass forms determined by availability and cost. To support the screening of diverse biomass forms for utilization in pyrolysis, NEA developed detailed reaction mechanisms to predict the complete distributions of all major products from any biomass form. Separate mechanisms describe primary devolatilization at heating rates fast enough to prevent tar deposition within the fuel, and secondary volatiles pyrolysis of tar, first, into PAH and, ultimately, into soot with simultaneous elimination of heteroatoms as noncondensables. These mechanisms predict the yields of tar, aromatic oils, light oxygenates, C 1 – C 4 hydrocarbons, soot, CO, CO 2 , H 2 O, H 2 , NH 3 , and H 2 S, plus the tar MWD and the elemental compositions of tar, soot, and char. The kinetics cover the domain of temperature (300-1200C), pressure (<1 – 50 atm), and transit times in advanced fluidized bed and entrained flow processing technologies. This paper emphasizes the validation of predicted product distributions with test data from lab-and pilot-scale facilities. Our validation database represents 2 cellulose samples, 7 woods and wood wastes, and 4 agricultural residues, and covers nearly the entire domain of elemental composition for biomass. One dataset completely covered the conversion of tar from two cellulose samples, and another determined the complete distributions of all major products from four diverse biomass samples with very good mass and elemental balance closures. Transient and temperature-dependent tar yields from all samples were simulated within the measurement uncertainties, with only a few stray discrepancies. Our kinetic analysis depicts the broad maxima in tar yields with temperature for the wood samples and cellulose, as well as the sharper maxima for corn stover, bagasse, red maple, and wheat straw. For every biomass sample, the correct temperature for maximum yield is apparent in the simulations, except for wheat straw.
... Temperature has big impact on liquid yields and it is well known that maximum liquid yields are generally achieved in the range of 450-550°C. To achieve fast pyrolysis conditions the biomass must be heated rapidly, the reaction time controlled and the products quenched quickly [64]. This has implications for the particle size, heating mechanisms, reactor design, and quench system [65]. ...
... DynaMotive's fast pyrolysis process evolved from experiments demonstrating flash pyrolysis of wood at the University of Waterloo in Canada [64,[79][80][81][82][83]. As shown in Fig. 4, the feed which is typically < 10 wt% moisture and < 3 mm in size, is fed into a bubbling fluidized bed reactor with a deep bed, which is heated to circa 430°C and has a gas residence time longer than 3 s [80,81]. ...
Article
Fast pyrolysis is a promising thermochemical method of producing renewable fuels and chemicals from biomass and waste feedstocks. There is much interest in optimising the choice of feedstock pre-treatments, reaction conditions, reactor designs, and catalysts as well as product upgrading steps to improve the techno-economic feasibility of the process. This article summarizes the current state-of-art in thermal and catalytic fast pyrolysis and outlines the major considerations for process development. The status of process technologies and development efforts on thermal and catalytic fast pyrolysis are reviewed, with a focus on efforts producing bio-oil for use in manufacturing transport fuels or fuel blends as the final product. The leading thermal pyrolysis processes, which use circulating, bubbling, auger screw and rotating cone reactor technologies, are reviewed alongside recent research and development activities on catalytic fast pyrolysis. This review finds that several technologies for thermal fast pyrolysis are operating at commercial scale, while integrated process development efforts are just starting to focus on applying catalytic fast pyrolysis at pilot scale. Processes for catalytic fast pyrolysis, either via in-situ or ex-situ upgrading of the bio-oil vapours is an area currently receiving significant research and development interest. This processing route may enable the production of partially upgraded bio-crudes which are suitable for processing to final fuel products in centralized bio-refineries or for co-processing in petroleum refineries. However, there remains a lot of fundamental and laboratory work to be done to develop deeper understanding of the processes, so that the catalysts and reaction conditions can be optimized. New combinations of unit operations and possibly novel reactors will likely be required to economically convert biomass feedstocks into partially upgraded bio-crudes. Techno-economic assessment shows that bio-fuels from fast pyrolysis may be competitive with petroleum fuels in future, however there are currently only a handful of plants operating commercially.
... A large variety of reactor types for fast pyrolysis has been investigated mainly at laboratory and pilot scale: ablative reactors in which the feedstock is heated by contact with a hot surface [54,56,63] like cyclone reactors [64][65][66][67][68], vortex reactors [54,[69][70][71][72], auger or double screw reactors [56,73,74], rotating cones, rotary kilns, and hearth furnaces [75][76][77]. Furthermore, reactors with mainly convective and conductive heat transfer such as fixed bed reactors [78,79], fluidized beds such as (conical) spouted beds [52,[80][81][82], bubbling/ stationary fluidized beds [51,53,55,56,63,83,84], fluidized beds with mechanical fluidization [85][86][87], and circulating fluidized bed reactors [88][89][90][91][92][93] have been applied to pyrolysis. Additionally, reactors that transport heat by means of radiation and convection: entrained flow reactors [94][95][96] and microwave pyrolysis reactors [97][98][99] have been used. ...
... A pilot plant for bubbling fluidized bed pyrolysis was developed at the Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario. Both plant description and experimental results for various biomass have been reported [51,83,84]. Reactor dimensions and operational parameters are given in Figure 5.7 and Table 5.9. ...
Book
In search of an alternative for chemicals and energy from fossil fuels, lignin pyrolysis is experimentally investigated in a circulating fluidized bed. Deviation in pyrolysis behavior of a softwood Kraft lignin and a wheat straw hydrolysis lignin is analyzed by means of char morphology as well as overall yield and composition determination for gas, oil, and char. The influence of catalytically active mineral matter in lignin on the product distribution is investigated. Progressively, the fluidized bed pyrolysis process is modeled semi-empirically considering fluid dynamics, feedstock composition, micro-particle pyrolysis reactions and mass balances. The lignin secondary reaction kinetics from oil–to–gas are obtained from the Kraft lignin experimental data and a pyrolysis plant with integrated char and permanent gas combustion is modeled with a flowsheeting tool.
... Several models have been developed and applied to simulate biomass pyrolysis process. Various feedstocks have been studied in order to determine the optimal conditions to produce higher homogenous pyrolysis liquids [14][15][16][17][18][19][20][21][22]. The main results selected from literature are summarized in Table 1. ...
... The selected flow rate of the feedstock stream is 62 kg/h of palm oil waste which represents 2000 MT/day of dry biomasses. Among the various operating conditions, it is well known that temperature and residence time are important parameters affecting the product yields [14][15][16][17][18][19][20][21][22]. Therefore, the effects of temperature and residence time on the product yields (bio-char, liquid and gas) during the fast pyrolysis of the biomass samples of palm shell, EFB and mesocarp fiber are examined (see Table 9). ...
... It is established that setups featuring very small particles and very low vapor residence times lead to high bio-oil yields, by mitigating the incidence of secondary reactions [92,111]. Wang et al. [112] demonstrated that a varying diameter on wood cylinders has a secondary effect on the liquid formation, but thicker cylinders led to higher water production. ...
... The heating rate of the biomass particles is of utmost importance for the pyrolysis process, impacting process control, product yields, and product quality [110,111,[118][119][120]. ...
Article
Full-text available
The social, economic, and environmental impacts of climate change have been shown to affect poorer populations throughout the world disproportionally, and the COVID-19 pandemic of 2020-2021 has only exacerbated the use of less sustainable energy, fuel, and chemical sources. The period of economic and social recovery following the pandemic presents an unprecedented opportunity to invest in biorefineries based on the pyrolysis of agricultural residues. These produce a plethora of sustainable resources while also contributing to the economic valorization of first-sector local economies. However, biomass-derived pyrolysis liquid is highly oxygenated, which hinders its long-term stability and usability. Catalytic hydrogenation is a proposed upgrading method to reduce this hindrance, while recent studies on the use of nickel and niobium as low-cost catalysts, both abundant in Brazil, reinforce the potential synergy between different economic sectors within the country. This review gathers state-of-the-art applications of these technologies with the intent to guide the scientific community and lawmakers alike on yet another alternative for energy and commodities production within an environmentally sustainable paradigm.
... Developments in fast pyrolysis may be traced back to a development programme by Occidental Petroleum, which was carried out in the US during the late 1960s and early 70s. The most important development work in this field, however, is indebted to the development at the University of Waterloo, Canada, by Professor Scott and his co-workers (Scott & Piskorz 1982). Another important development started at the University of Western Ontario and eventually led to the establishment of Ensyn Technologies (Freel & Graham 1991). ...
Article
Full-text available
This publication is an updated version of a study on testing and modifying standard fuel oil analyses (Oasmaa et al. 1997, Oasmaa & Peacocke 2001). Additional data have been included to address the wide spectrum of properties that may be required in different applications and to assist in the design of process equipment and power generation systems. In addition, information on specifications and registration is provided. Physical property data on a range of pyrolysis liquids from published sources have been added to provide a more comprehensive guide for users.
... The inception of modern day fast pyrolysis process occurred in the University of Waterloo in early 1980s (Scott and Piskorz, 1982). However, until today, the commercialization of pyrolysis oil has been dawdling which is now on the verge of being stagnant. ...
Article
To impart usability in waste based biomass through thermo-chemical reactions, several physical and chemical pre-treatments were conducted to gain an insight on their mode of action, effect on the chemistry and the change in thermal degradation profiles. Two different waste biomasses (Douglas fir, a softwood and hybrid poplar, a hardwood) were subjected to four different pre-treatments, namely, hot water pre-treatment, torrefaction, acid (sulphuric acid) and salt (ammonium phosphate) doping. Post pre-treatments, the changes in the biomass structure, chemistry, and thermal makeup were studied through electron microscopy, atomic absorption/ultra violet spectroscopy, ion exchange chromatography, and thermogravimetry. The pre-treatments significantly reduced the amounts of inorganic ash, extractives, metals, and hemicellulose from both the biomass samples. Furthermore, hot water and torrefaction pre-treatment caused mechanical disruption in biomass fibres leading to smaller particle sizes. Torrefaction of Douglas fir wood yielded more solid product than hybrid poplar. Finally, the salt pre-treatment increased the activation energies of the biomass samples (especially Douglas fir) to a great extent. Thus, salt pre-treatment was found to bestow thermal stability in the biomass. Copyright © 2015 Elsevier B.V. All rights reserved.
... A direct coal liquefaction process with subsequent upgrading to transportation fuels, rescaled to 100 t/h of feed and in year 2014, had estimated capital cost of ∼600 M$. 45 The higher investment of the liquefaction process, compared to pyrolysis, is due to the oil fractionation and recycle. However, the higher investment is well compensated by the higher biocrude yield (∼90 C %) in the liquefaction process, compared to the oil yield in the pyrolysis process (∼50−70 C %), [19][20][21]25,46,47 which makes the production cost competitive. The energy yield is also significantly higher in the liquefaction process compared to the pyrolysis. ... Article The direct thermal liquefaction of lignocellulose can provide a biocrude that could be used as a precursor for biofuels. However, earlier attempts to use the whole reactor effluent as a liquefaction medium, by recycling it to the liquefaction reactor, were hampered by the buildup of heavy products. This paper reports on the integration of the liquefaction reaction and the fractionation of the reactor effluent to recover and recycle the light oil fraction of it to be used as a liquefaction solvent. The fractionation is based on solvent extraction and temperature-swing regeneration. Here, we demonstrate steady-state liquefaction of pine wood with high and constant liquid yields (90 C %) and constant liquid qualities over several recycles. The liquefaction was done at a temperature of 320 C and at a pressure of 7-10 MPa. Process simulation confirms a significant savings in energy demand by incorporating the extraction in the process, compared to an alternative liquefaction/distillation scheme. A techno-economic assessment further estimates that a biocrude could be produced at an energy-equivalent crude oil price of 54$/barrel at a wood cost of 85 $/dry ton. (Figure Presented). ... Generally, it is a carefully controlled process that produces a high liquid yield. The process has been widely demonstrated using hardwood solid waste to produce organic liquid yield as high as 70% of the feed material [50]. It is a process in which the pyrolysis reactor works on a very unique principle in which the char is not allowed to accumulate in the bed while the treatment of the sand may not be necessary. ... ... The inception of modern day fast pyrolysis process occurred in the University of Waterloo in early 1980s (Scott and Piskorz, 1982). However, until today, the commercialization of pyrolysis oil has been dawdling which is now on the verge of being stagnant. ... Article Douglas fir wood, a forestry waste, was attempted to be converted into value added products by pretreatments followed by pyrolysis. Four different types of pretreatments were employed, namely, hot water treatment, torrefaction, sulphuric acid and ammonium phosphate doping. Subsequently, pyrolysis was done at 500°C and the resulting bio-oils were analysed for their chemical composition using Karl Fischer titration, thermogravimetry, ion exchange, and gas chromatography. Pretreatment with acid resulted in the highest yield of bio-oil (~60%). The acid and salt pretreatments were responsible for drastic reduction in the lignin oligomers and enhancement of water content in the pyrolytic liquid. The quantity of xylose/mannose reduced as a result of pretreatments. Although, the content of fermentable sugars remained similar across all the pretreatments, the yield of levoglucosan increased. Pretreatment of the biomass with acid yielded the highest amount of levoglucosan in the bio-oil (13.21%). The acid and salt pretreatments also elevated the amount of acetic acid in the bio-oils. Addition of acid and salt to the biomass altered the interaction of cellulose-lignin in the pyrolysis regime. Application of pretreatments should be based on the intended end use of the liquid product having a desired chemical composition. Copyright © 2015 Elsevier B.V. All rights reserved. ... Pirolisi erreaktore gehienak presio atmosferikoan lan egiten dute, beraz, elikadura sistemak ez dute oso konplexuak izan behar. Erreaktore diseinu gehienetan sistema pneumatikoak (Scott eta Piskorz 1982, Berruti et al., 2009) eta torloju erakoak erabiltzen dira. Burbuiladun ohantze fluidizatuetan (1.7.1. ... ... Perhaps most importantly, the Liden et al model does not consider the impact of widely distributed biomass particle residence times, which are known to be important in both bubbling and circulating beds. Nevertheless, the Liden et al approach provides a reasonable starting point that has been extensively validated with experiments using a wide range of biomass feedstocks [Scott and Piskorz (1982), Scott et al (1984), and Scott et al (1985)]. ... ... The process of flash pyrolysis is strongly influenced by the residence time (Shuangning et al. 2006), a process defined as "reactor void volume divided by the fluidisation and feeding carrier gas flow rate at reactor conditions of biomass within the reactor" (Scott and Piskorz 1982). This can be attributed to the fact that the pyrolysis reaction commences immediately after the biomass is injected into the reactor. ... Article Full-text available To assuage global consumer demand for energy, there is a need for increased biofuel production. Flash pyrolysis is an important technique for biomass conversion into eco-friendly biofuels. This review discusses the research progress and key findings made over the years on the flash pyrolysis of biomass. Flash pyrolysis oil yields can be as high as 60–75 wt% at optimised conditions. For the process to be effective, temperature, heating rate and residence time would be within the range of 450–600 °C, 103-104\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${10}^{3}- {10}^{4}$$\end{document} °C/s and < 1 s. Flash pyrolysis oil is characterised by high water content (usually > 15 wt%). The main pyrolysis products of lignin part biomass are phenols. The phenolic part includes phenols, hydroxylphenols, meothoxyphenols, dimethoxyphenols. Flash pyrolysis products of biomass (as with other pyrolysis types) must be upgraded before use. They are unstable, re-polymerised and are not miscible with hydrocarbons. The future of the technology is promising as products obtained can serve as better feedstock for other re-refining processes (compared to other pyrolysis process types). Furthermore, it is faster and can handle higher feedstock volumes at similar reactor volumes and process intricacies. Due to the advantages of product yield, it is an important technology that should be explored for energy conversion of biomass and can also serve as a solid waste management technique. Graphical abstract ... Fast pyrolysis is a potential pathway for producing significant quantities of renewable liquid fuels, often referred to as bio-liquids or bio-oils, from lignocellulosic biomass materials [6, 7]. Much of the ground work on biomass pyrolysis dates back to studies by Shafizadeh [8, 9] and Scott [10, 11] in the 1970's. With significant contributions from Elliot [12], Kandiyoti [6], Antal [13, 14], Diebold [15, 16], Oasmaa [17, 18] and Czernik [15, 19], throughout the 1980's and 1990's. ... Article Full-text available A reactor was designed and commissioned to study the fast pyrolysis behavior of bana-grass as a function of temperature and volatiles residence time. Four temperatures between 400 and 600°C were examined as well as four residence times between ~1.0 and 10 seconds. Pyrolysis product distributions of bio-oil, char and permanent gases were determined at each reaction condition. The elemental composition of the bio-oils and chars was also assessed. The greatest bio-oil yield was recorded when working at 450°C with a volatiles residence time of 1.4 s, ~37 wt% relative to the dry ash free feedstock (excluding pyrolysis water). The amounts of char (organic fraction) and permanent gases under these conditions are ~4 wt% and 8 wt% respectively. The bio-oil yield stated above is for 'dry' bio-oil after rotary evaporation to remove solvent, which results in volatiles and pyrolysis water being removed from the bio-oil. The material removed during drying accounts for the remainder of the pyrolysis products. The 'dry' bio-oil produced under these conditions contains ~56 wt% carbon which is ~40 wt% of the carbon present in the feedstock. The oxygen content of the 450°C, 1.4 s 'dry' bio-oil is ~38 wt%, which accounts for ~33 wt% of the oxygen in the feed-stock. At higher temperature or longer residence time less bio-oil and char is recovered and more gas and light volatiles are produced. Increasing the temperature has a more significant effect on product yields and composition than increasing the volatiles residence time. At 600°C and a volatiles residence time of 1.2 seconds the bio-oil yield is ~21 wt% of the daf feedstock, with a carbon content of 64 wt% of the bio-oil. The bio-oil yield from banagrass is significantly lower than from woody biomass or grasses such as switchgrass or miscanthus, but is similar to barley straw. The reason for the low bio-oil yield from banagrass is thought to be related to its high ash content (8.5 wt% dry basis) and high concentration of alkali and alkali earth metals (totaling ~2.8 wt% relative to the dry feedstock) which are catalytic and increase cracking reactions during pyrolysis. ... However the elemental composition of the condensed vapour has not been measured in our experiments because the mass of recovered liquid is so small (few milligrams) that it is not possible to sample it for further elemental analysis. Former experiments achieved with different apparatus have shown that the elemental composition of the primary tars obtained by fast pyrolysis does not vary significantly with heat source temperature (31,32). As a consequence, it is considered that the organic part of the vapour phase has a constant elemental composition: C tar = 50.0 ... Thesis Full-text available Les procédés de pyrolyse et gazéification permettent de convertir la biomasse en différents vecteurs énergétiques (carburants, électricité, chaleur). Ces procédés thermochimiques pourraient ainsi contribuer à la diminution des émissions de GES, mais leur mise en œuvre à l’échelle industrielle reste lente. En plus des difficultés réglementaires et économiques, il existe un manque de prévisibilité de leurs performances technique, énergétique et environnementale. La simulation fine des réacteurs thermochimiques pourrait ainsi contribuer à l’émergence de ces filières bio-sourcées, mais elle se heurte à la variabilité de la biomasse ligno-cellulosique et à la complexité des phénomènes rencontrés. Ce mémoire expose les travaux entrepris par l’auteur sur cette problématique multi-échelle et se focalise en particulier sur la modélisation de la pyrolyse à l’échelle de la particule, qui est le phénomène commun à tous les réacteurs thermochimiques. Les modèles développés sont confrontés à des résultats expérimentaux obtenus sur des bancs d’essais originaux (four à image, micro-lit fluidisé, lit fluidisé 5kg/h). ... The cost of production is an important factor that decides the fate of any process on the substantial scale. The studies on economic analysis of bio-oil production, conducted in 80's and early 90's, by Scott and Piskorz [250], Beckman et al. [251], Cottam and Bridgwater [252], Freel et al. [253], and Solantausta et al. [162] gave the cost of production of bio-oil higher than the cost of light fuel oil at that time, by a factor of 1.09e2.7. Biomass prices have a strong influence on the economics of the process [247]. ... Article In the pursuit of renewable sources of energy, biomass is emerging as a promising resource because of its abundance and carbon neutral nature. Pyrolysis is a prevailing technology for biomass conversion into the valuable hydrocarbon and alternative fuels. In this review, pyrolysis of lignocellulosic biomass has been addressed, focusing primarily on the ideal feedstock, technologies, reactors, and properties of the end product. Technical problems in using biofuel from pyrolysis, as transport fuel have also been discussed, along with solutions to address these challenges, and comments on the future scope of the pyrolysis process. ... Developments in fast pyrolysis may be traced back to a development programme by Occidental Petroleum, which was carried out in the US during the late 1960s and early 70s. The most important development work in this field, however, is indebted to the development at the University of Waterloo, Canada, by Professor Scott and his co-workers (Scott & Piskorz 1982). Another important development started at the University of Western Ontario and eventually led to the establishment of Ensyn Technologies (Freel & Graham 1991). ... Article The main purpose of the study was to test the applicability of standard fuel oil methods developed for petroleum-based fuels to pyrolysis liquids. In addition, research on sampling, homogeneity, stability, miscibility and corrosivity was carried out. The standard methods have been tested for several different pyrolysis liquids. Recommendations on sampling, sample size and small modifications of standard methods are presented. In general, most of the methods can be used as such but the accuracy of the analysis can be improved by minor modifications. Fuel oil analyses not suitable for pyrolysis liquids have been identified. Homogeneity of the liquids is the most critical factor in accurate analysis. The presence of air bubbles may disturb in several analyses. Sample preheating and prefiltration should be avoided when possible. The former may cause changes in the composition and structure of the pyrolysis liquid. The latter may remove part of organic material with particles. The size of the sample should be determined on the basis of the homogeneity and the water content of the liquid. The basic analyses of the Technical Research Centre of Finland (VTT) include water, pH, solids, ash, Conradson carbon residue, heating value, CHN, density, viscosity, pour point, flash point, and stability. Additional analyses are carried out when needed. ... The University of Waterloo in Canada pioneered the science of fast pyrolysis and established a clear lead in this area for many years [18,19] . Fluid beds have been selected for further development by several companies, for example Union Fenosa [20] , who built and operated a 200 kg$h -1 pilot unit in Spain based on the University of Waterloo process (it was dismantled some years ago), and Dynamotive, who operated a 75 kg$h -1 and 400 kg$h -1 pilot unit [21] in Canada based on an RTI design and have subsequently built a 100 t$d -1 and a 200 t$d -1 plant in Canada. ...
Article
Full-text available
Increased demand for liquid transportation fuels, environmental concerns and depletion of petroleum resources requires the development of efficient conversion technologies for production of second-generation biofuels from non-food resources. Thermochemical approaches hold great potential for conversion of lignocellulosic biomass into liquid fuels. Direct thermochemical processes convert biomass into liquid fuels in one step using heat and catalysts and have many advantages over indirect and biological processes, such as greater feedstock flexibility, integrated conversion of whole biomass, and lower operation costs. Several direct thermochemical processes are employed in the production of liquid biofuels depending on the nature of the feedstock properties: such as fast pyrolysis/liquefaction of lignocellulosic biomass for bio-oil, including upgrading methods, such as catalytic cracking and hydrogenation. Owing to the substantial amount of liquid fuels consumed by vehicular transport, converting biomass into drop-in liquid fuels may reduce the dependence of the fuel market on petroleum-based fuel products. In this review, we also summarize recent progress in technologies for large-scale equipment for direct thermochemical conversion. We focus on the technical aspects critical to commercialization of the technologies for production of liquid fuels from biomass, including feedstock type, cracking catalysts, catalytic cracking mechanisms, catalytic reactors, and biofuel properties. We also discuss future prospects for direct thermochemical conversion in biorefineries for the production of high grade biofuels.
... Early research on biomass pyrolysis in fluidised beds was pioneered by the researchers at the University of Waterloo in Canada (Scott and Piskorz, 1982;Scott and Piskorz, 1984;Scott et al., 1985) which led to the development of RTI process (Scott et al., 1999). Based on the RTI process, Dynamotive built a 100 tonne per day and 200 tonne per day plants in Canada (Bridgwater, 2012). ...
Thesis
Global challenges related to energy security, resource sustainability and the environmental impacts of burning fossil fuels have led to an increasing need for switching to the use of clean and sustainable resources. Bio-oil produced through pyrolysis has been suggested as one of the sustainable alternatives to fossil resources for power generation as well as chemicals and biofuels production. Pyrolysis is a thermochemical process during which the biomass feedstock is heated in an inert atmosphere to produce gas, liquid (bio-oil) and solid (char) products. Microwave heating has been considered a promising technique for providing the energy required for biomass pyrolysis due to its volumetric and selective heating nature which allows for rapid heating in a cold environment. This helps to preserve the product quality by limiting secondary reactions. The aim of this research was to study the interactions between biomass materials and microwave energy during pyrolysis, and to develop a reliable and scalable microwave pyrolysis process. The dielectric properties of selected biomass materials were studied and found to vary significantly with temperature due to the physical and structural changes happening during pyrolysis. The loss factor of the biomass materials was found to reach a minimum value in the range between 300 oC and 400 oC followed by a sharp increase caused by the char formation. A microwave fluidised bed process was introduced as an attempt to overcome the challenges facing the scaling-up of microwave pyrolysis. The concept of microwave pyrolysis in a fluidised bed process was examined for the first time in this thesis. A systematic approach was followed for the process design taking into account the pyrolysis reaction requirements, the microwave-material interactions and the fluidisation behaviour of the biomass particles. The steps of the process design involved studying the fluidisation behaviour of selected biomass materials, theoretical analysis of the heat transfer in the fluidised bed, and electromagnetic simulations to support the cavity design. The developed process was built, and batch pyrolysis experiments were carried out to assess the yield and quality of the product as well as the energy requirement. Around 60 % to 70 % solid pyrolysed was achieved with 3.5 kJ·g-1 to 4.2 kJ·g-1 energy input. The developed microwave fluidised bed process has shown an ability to overcome many of the challenges associated with microwave pyrolysis of biomass including improvement in heating uniformity and ability to control the solid deposition in the process, placing it as a viable candidate for scaling-up. However, it was found to have some weaknesses including its limitations with regards to the size and shape of the biomass feed. Microwave pyrolysis of biomass submerged in a hydrocarbon liquid was introduced for the first time in this thesis as a potential alternative to overcome some of the limitations of the gas-based fluidised bed process. Batch pyrolysis experiments of wood blocks submerged in different hydrocarbon liquids showed that up 50 % solid pyrolysis could be achieved with only 1.9 kJ·g-1 energy input. It was found that the overall degree of pyrolysis obtained in the liquid system is lower than that obtained from the fluidised bed system. This was attributed to the large temperature gradient between the centre of the biomass particle/block and its surface in the liquid system leaving a considerable fraction of the outer layer of the block unpyrolysed. It was shown that the proposed liquid system was able to overcome many of the limitations of the gas-based systems.
... 43 Fast pyrolysis of poplar at atmospheric pressure commonly provides tar yields of 65%. 44 Vacuum pyrolysis of poplar at 315°C gave yields of 52.8% oil, 27.7% char, 12.3% water, and 7.2% gas. 45 In another study, Roy et al. 46 compared pyrolysis yields under vacuum (10 kPa) and close to atmospheric pressure (80 kPa) at 450°C and reported yields of 50.0 and 39.7 wt % oil, respectively. ...
Article
Thin films (~115 µm thick) of milled wood lignin from hybrid poplar and acid-washed hybrid poplar were pyrolyzed at 500 °C and ~55 °C/s at five pressures (4, 250, 500, 750, and 1000 mbar) to determine the impact of secondary liquid intermediate reactions on the product distribution. For both milled wood lignin extracted from poplar and acid washed hybrid poplar wood, pressure had a significant effect on the product distribution for thin film pyrolysis between 4 and 1000 mbar. For lignin, lowering the pressure from 1000 mbar to 4 mbar reduced the char yield from 36 % to 23 % and enhanced production of large cluster pyrolytic lignin. However, the pressure did not dramatically impact the gas yield (CO2, CO, methane, H2, ethane, propane, and butane), nor did it significantly impact the release of monomeric phenolic compounds. ICR-MS shows limited changes in the composition of lignin oligomers. The increase in the production of large lignin oligomers observed by UV fluorescence and the reduction of char yield with vacuum confirm the importance of oligomeric combination reactions to form large polyaromatic structures in the liquid intermediate. For hybrid poplar, lowering the pressure from 1000 mbar to 4 mbar decreased the char yield from 19 % to 7 % and enhanced production of heavy sugars (cellobiosan and cellotriosan). ICR-MS results clearly show the importance of dehydration reactions in the liquid intermediate. Lowering the pressure also enhanced production of CO, CO2, and methane due to heterogeneous catalysis by residual alkali and alkaline earth metals in the solid wood matrix. However, it also decreased production of levoglucosan from 10 to 6.1 wt.%. The yields of levoglucosan and cellobiosan obtained for hybrid poplar were higher and lower, respectively, compared with those expected if the pyrolysis products were the result of the additive contribution of hybrid poplar constituents. This result could be explained by the tendency of lignin liquid intermediate to bubble vigorously, contributing in this way to the removal of cellulose oligomers from the liquid intermediate.
... They reported bio-oil yields as high as $80% from very finely divided ($0.1 mm) clean Aspen Poplar wood and extremely short gas residence tines (< 1 s). The process was scaled up to 3 kg/h pilot plant (Fig. 4) [21], with similar results (Tab. 1). ...
... Biofuels are increasingly valued as the renewable alternative for stationary power generation and transportation applications due to the increased concerns over the global climate change arising from the greenhouse gas (GHG) emissions and depletion of the conventional fossil fuels, because biofuels are potentially carbon neutral [1][2][3][4][5][6]. For remote communities, it is conventional to transport in fossil fuels with expensive transport cost, and emissions in environmentally sensitive areas. ...
Article
Air-assisted atomization of the sprays produced by injecting different types of highly viscous pyrolysis oils are studied. Different breakup and atomization regimes are characterized using the long distance microscopic imaging technique. The high resolution imaging reveals detailed underlying two-phase interactions in pyrolysis oil injection that are found unlike other conventional liquid fuels. Several cases of droplet size characterization are carried out using the Malvern’s laser diffraction measurements under variable liquid flow rates, atomizing air flow rates and oil preheating temperatures. The time-averaged and high resolution instantaneous images reveal that the highly viscous nature of pyrolysis oils prevent the instability mechanisms from efficiently atomizing the liquid. The present broad set of measured data suggest that the atomization quality of pyrolysis oils can be optimized by applying a combination of liquid preheating and air-assisted atomization. The flow visualizations reveal the transition from ligament-dominated two-phase flow field into fully atomized sprays when proper oil preheating temperatures and sufficient atomizing air flow rates are provided. Visualized observations are quantitatively verified using the droplet size distribution measurements as well as the Sauter mean diameter (SMD) values for several measurement conditions.
... The bio-oil yields from the ablative fast pyrolysis (AFP) of BW and PW reached almost 60 wt% single-phase liquid (Fig. 2A). These results are very close to those achieved by researchers using fluidized bed [10,11,[31][32][33] or packed bed [34] pyrolysis. However, such units require much smaller feed particles sawdust (<1 mm) for the fluid bed and pellets (<5 mm) for packed bed pyrolysis. ...
Article
One of the easiest ways to minimize the overall costs of bio-oil production is to minimize biomass transportation and, thus, pyrolysis should be performed at or close to the biomass original location. Thus, we applied ablative fast pyrolysis (AFP), as the only potentially mobile pyrolysis unit, to convert residual lignocellulosic biomass into bio-oil. Four different biomass types were converted to bio-oils: beech and poplar wood, straw and miscanthus. To study reliably the influence of biomass type on bio-oil yields, physicochemical properties and composition, pyrolysis was carried out at a constant temperature of 550 °C. Titrations and spectroscopic methods were used for the characterization of the main oxygenate groups. GC-MS was used for the quantification of more than 120 volatile compounds. Such a thorough analytical study of AFP bio-oils, heretofore missing in scientific literature, allowed us to reliably discuss the differences in bio-oils´ relative to the knowledge of biomass composition. Significant differences between the bio-oils were observed, with the lowest content of carboxylic and carbonyl groups in the straw bio-oil. The amount of carboxylic and phenolic groups in all the bio-oils was in the typical range observed for bio-oils unlike the carbonyls´ and levoglucosan content, which was lower than typical for bio-oils from other pyrolysis units.
... As previously mentioned, forest biomass residues have a varied lignocellulosic composition, and, thus, their physicochemical characteristics and the percentage of bio-oil, biochar, and syngas vary greatly, depending upon the tree species and the thermochemical operational parameters that are chosen. According to Scott and Piskorz [100], the percentages of biochar, bio-oil, and gas after flash pyrolysis of hybrid aspenpoplar sawdust at 425°C and 500°C were of 31 and 11%, 60 and 78%, and 6 and 12%, respectively. For example, the chemical composition of the bio-oil also varied with the temperature in terms of percentage of acetaldehyde, ethanol, acetic acid, acetone, furan, methanol, and formaldehyde, among others. ...
Article
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Purpose of Review For the past few decades, consumers have increasingly demanded biodegradable, petroleum-free, and safe products for the environment, humans, and animals, with improved performance. In terms of energy consumption, modern society has progressively sought to reduce fossil fuel utilization and greenhouse gas emissions. This review presents and discusses the possibilities of using biomass residues that are derived from forest operations and wood manufacturing to produce biofuels and biomaterials as sustainable alternatives that could boost the development of renewable technologies and bio-economy. Recent Findings Forest biomass residues are composed primarily of cellulose, hemicellulose, and lignin in varying proportions depending upon the species. Residues from forest operations have heterogeneous compositions due to the presence of branches, foliage, tree tops, and bark, compared with those derived from wood manufacturing industries. Several technological approaches have been developed to add value to forest biomass residues through their conversion to biomaterials such as wood-based composite panels, wood-plastic composites, wood pellets, and biofuels, such as biochar, bio-oil, syngas (thermochemical approach), and biogas (biochemical approach). Summary Forest biomass residues are valuable lignocellulosic materials, but research is still required regarding their conversion into value-added products given their heterogeneous compositions and varied physicochemical properties. Obstacles such as transportation costs and their complex structural and chemical mechanisms that resist decomposition need to be better overcome in developing high-quality and economically viable biofuels and biomaterials. In contrast, wood-based panels, composites, pellets, and biofuels produced by the wood manufacturing industries exhibit superior properties and characteristics for commercialization. Recent studies regarding valorization of forest biomass residues are a welcome recognition of the need to transition to a sustainable economy, and a definitive strategy for achieving objectives that have been set for reducing greenhouse gas emissions.
... However, like marabu, scientific investigations into its other applications are limited. Scott and Piskorz [40] investigated the production of tar-like oil from aspen; Kalkreuth et al. [24] performed optical characterisation of aspen pyrolysis products using fluorescence and reflectance measurements. Both these works focussed on the liquid products of aspen pyrolysis while the characteristics of aspen biochars have not been reported in literature. ...
Article
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Marabu (Dichrostachys cinerea) from Cuba and aspen (Populus tremula) from Britain are two rosid angiosperms that grow easily, as a weed and as a phytoremediator, respectively. As part of scientific efforts to valorise these species, their barks and woods were pyrolysed at 350, 450, 550 and 650 °C, and the resulting biochars were characterised to determine the potential of the products for particular applications. Percentage carbon composition of the biochars generally increased with pyrolysis temperature, giving biochars with highest carbon contents at 650 °C. Biochars produced from the core marabu and aspen wood sections had higher carbon contents (up to 85%) and BET surface areas (up to 381 m² g⁻¹) than those produced from the barks. The biochar porous structures were predominantly mesoporous, while micropores were developed in marabu biochars produced at 650 °C and aspen biochars produced above 550 °C. Chemical and thermal activation of marabu carbon greatly enhanced its adsorption capacity for metaldehyde, a molluscicide that has been detected frequently in UK natural waters above the recommended EU limit.
... The objective of the process is to maximize the liquid yield and minimize the production of char and gases. This requires fast heating of the biomass and produces bio-oil (60% by weight) and other products including gas and char [49]. On the other hand, slow pyrolysis takes several hours to complete with bio-char being the main product. ...
... Developments in fast pyrolysis may be traced back to a development programme by Occidental Petroleum, which was carried out in the US during the late 1960s and early 70s. The most important development work in this field, however, is indebted to the development at the University of Waterloo, Canada, by Professor Scott and his co-workers (Scott & Piskorz 1982). Another important development started at the University of Western Ontario and eventually led to the establishment of Ensyn Technologies (Freel & Graham 1991). ...
Technical Report
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This publication is an updated version of a study on testing and modifying standard fuel oil analyses (Oasmaa et al. 1997, Oasmaa & Peacocke 2001). Additional data have been included to address the wide spectrum of properties that may be required in different applications and to assist in the design of process equipment and power generation systems. In addition, information on specifications and registration is provided. Physical property data on a range of pyrolysis liquids from published sources have been added to provide a more comprehensive guide for users.
... Developments in fast pyrolysis may be traced back to a development programme by Occidental Petroleum carried out in the US during the 1970s. The most important development work in this field is, however, the result of development at the University of Waterloo, Canada by Professor Scott and his co-workers (Scott & Piskorz 1982). Another important development started at the University of Western Ontario and eventually led to the establishment of Ensyn Technologies (Freel & Graham 1991). ...
Technical Report
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Fast pyrolysis bio-oils are supposed to replace fuel oils in many stationary applications including boilers and furnaces. However, these bio-oils are completely different from petroleum fuels and other bio-oils in the market, like biodiesels, as regards both their physical properties and chemical composition. When the unusual properties of these bio-oils are carefully taken into account, their combustion without a pilot flame or support fuel is possible on an industrial scale. Even blending of these oils with alcohols in order to improve combustion is not necessarily required. In the recent industrial scale bio-oil combustion tests, bio-oil has been found to be technically suitable for replacing heavy fuel oil in district heating applications. This kind of replacement, however, needs some modifications to be made to the existing units, which need to be engineered carefully. For example, all the parts in contact with bio-oil should be replaced with parts made of stainless steel or better, and the suitability of all gaskets and instruments needs to be checked. In general, the emissions in the bio-oil combustion are very dependent on the original levels of solids, water and nitrogen in the oil being combusted. Typically, the emissions levels are between those of light fuel oil and the lightest heavy fuel oil, but particulate emission may be higher. On the other hand, there are practically no SOx-emissions generated in the bio-oil combustion. The NOx-emission in bio-oil combustion mainly originates from fuel-bound nitrogen. Staged combustion for NOx-reduction may be recommended, as successful air staging in natural gas, heavy and light fuel oil combustion has already been done. The recent bio-oil combustion tests have also shown that bio-oil combustion technology works well, and there are not many possibilities of further lowering particulate emissions, since the majority of the particulates are typically incombustible matter. Therefore, it is recommended to reduce the solids content of the biooil to < 0.1 wt% if possible, and to ensure that inorganics in t
... The yield trends for carbon monoxide and carbon dioxide are similar to those reported by Scott and Piskorz [7] for aspen-poplar, a woody feedstock. They also showed carbon dioxide yields rising less quickly over 550°C and a sharp rise in carbon monoxide yields at higher temperatures. ...
Data
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... The yield trends for carbon monoxide and carbon dioxide were similar to those reported by Scott and Piskorz [36] for aspen-poplar, a woody feedstock. They also showed carbon dioxide yields levelling off over 550 C and a sharp rise in carbon monoxide yields. ...
... A comparison of EFB with results from the literature for other biomass feedstocks is presented in Fig. 8 and Table 5. The product yields for washed EFB are similar to those for a low ash wood, such as poplar, while the product yields for unwashed EFB are much closer to those for higher ash feedstocks, such as wheat straw [18,11]. Fig. 9 shows a schematic flow diagram of the 1 kg/h fluidised bed pyrolysis system. ...
Data
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Article
Fast pyrolysis was used to convert waste biomass into bio-oil, which has a benefit of storage and transportation with the potential as a fossil oil substitute. Pakistani cotton stalk was pyrolyzed in a bench-scale bubbling fluidized bed reactor. The effect of reaction conditions such as temperature and feed size on the bio-oil, char and gas yields was investigated. The optimal pyrolysis temperature for the production of bio-oil was 490 °C which gave the maximum yield (36 wt%) of product at feed size of 1.0 mm. Bio-oil yield increased with the increase in temperature, while the yield of char decreased. The various properties of bio-oil attained under these pyrolysis conditions were defined. Chemical composition of bio-oil was determined using FTIR and GC–MS analysis, and major chemical compounds were phenols, carboxylic acids, ketones, aldehydes, furans and sugars.
Chapter
Biomass, as the only renewable source of fixed carbon, has attracted considerable attention as a renewable energy resource after the oil crises of the last 15 years. Of the variety of technologies available for converting biomass into more useful and valuable energy products, thermochemical processing and particularly pyrolysis have been investigated for the economic production of liquid fuels. The characteristics of pyrolysis processes, upgrading technologies and products are summarised in this overview paper in order to focus on the opportunities, constraints and requirements for successful implementation of these technologies in Europe.
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Crude pyrolysis bio-oil can be used as energy vector, but further upgrading is required before its utilization as transportation fuel and alternative hydrogen source. Therefore, the catalytic hydrogenation process of several model compounds (i.e. ether, alcohol, acid, olefin and guaiacol) and of crude bio-oil obtained by fast pyrolysis of nuts waste biomass has been investigated using CoMo/Al2O3 catalysts, pre-sulfided in flowing H2S at 400°C, with different textural properties under simulated industrial conditions (T, 250-300°C; P, 10-20bar). Depending on the chemical structure of the various compounds, a complex reaction network, involving mostly hydro-deoxygenation (HDO), hydrogenation (HYD) and hydrocracking (HCR) processes, occurs. The simultaneous proceeding of all these reactions during the hydrotreating (HDT) of the crude bio-oil implies the formation of a wide range of hydrocarbon compounds documenting the feasibility of the upgrading process to obtain liquid transportation fuels and hydrogen-source compounds.A scale of reactivity based on the effectiveness of hydrogenation of compounds and functional groups has been proposed, also providing evidence of the effects of the texture and physico-chemical properties on the activity and selectivity of the CoMo sulfided catalysts in the HDT processes.
Article
An estimated 8.3 billion tonnes of plastic waste has been generated globally since the 1950s of which approximately 80% remains in landfill or loose in the environment.1 Global greenhouse gas emissions from the production and disposal of plastics is more than double that of air travel.2 In line with current demand, oil-based plastics are produced at a rate of ~350mtpa. While useful, fossil-derived plastics have been developed focusing on function rather than end-of-life performance and their environmental impact. Recycling alone is not the complete answer to the "plastics problem". These include cost, food contamination, polymer degradation and environmental leakage. Bio-based plastics are an important part of the solution. This work demonstrates a novel approach to going some way towards solving the “plastic problem” by adding value to biomass pyrolysis liquids through transesterification of the diverse range of alcohol functional groups within the mixture to give rise to polymerizable monomers from biomass, without requiring extensive separation. Previous studies have worked on using highly reactive acyl chlorides/acid anhydrides on model compounds to achieve similar results. Using transesterification, production of the monomer is achieved in one reaction step and without separation or the use of toxic reagents. Strategies to tune the process to vary glass transition temperature (Tg) and Mp are discussed. A scheme of future work to exploit this in applications is included.
Patent
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Methods for fractional catalytic pyrolysis which allow for conversion of biomass into a slate of desired products without the need for post-pyrolysis separation are described. The methods involve use of a fluid catalytic bed which is maintained at a suitable pyrolysis temperature. Biomass is added to the catalytic bed, preferably while entrained in a non-reactive gas such as nitrogen, causing the biomass to become pyrolyzed and forming the desired products in vapor and gas forms, allowing the desired products to be easily separated
Article
The demand for energy has been increasing in the current decade due to rapid industrialization and urbanization. Limited fossil fuel resources, rising fuel prices, and global warming are some of the factors leading to increased interest in lignocellulosic biomass to generate renewable fuels. Forestry residues which contain a major proportion of lignocellulosic matter are suitable candidates for conversion to liquid and gaseous fuels. This review highlights forestry biomass from a bioenergy point of view, focusing on its global applications, availability, chemical composition, and conversion. The conversion pathways discussed here are biochemical conversion to ethanol and butanol as well as thermochemical conversions, including pyrolysis, liquefaction, and gasification, to produce process-specific end products such as bio-oil and synthesis gas. A wide variety of woody biomass species are also discussed, indicating their variation in cellulose, hemicellulose, and lignin content; bio-oil, biochar, and gas yields through pyrolysis; and bioethanol and biobutanol yields through bioconversion.
Article
The bio-oil model upgrading was studied over a series of catalysts in the CO/H2O system. The impregnation method was superior to the dry mix method. 6 % of Ni impregnating in B206 catalyst is the optimum bi-functional catalyst. The optimum catalyst showed the highest activity for deoxygenation in the CO/H2O system, the deoxygenation rate was up to 92 % and the dehydration rate was 89 % in a certain conditions after upgrading.
Chapter
There is considerable interest in the production of liquid fuels, chemicals and electricity from biomass by the thermochemical conversion processes of flash pyrolysis and liquefaction. The crude bio-oil produced can be used to substitute for conventional fossil fuels or can be upgraded to a higher quality fuel by hydrotreating or zeolite synthesis. Either product can be used to generate electricity in an engine or turbine. A computer program has already been developed to assess the different thermochemical and biochemical routes for liquid fuels production from biomass [1]. This concentrated mainly on the thermochemical conversion of biomass by gasification and had only generic direct liquefaction models. A new computer program is now under development to particularly model the flash pyrolysis and liquefaction of biomass with subsequent upgrading and refining of the crude liquid products to produce higher value and more marketable liquid fuel products. There will be also be the possibility of determining the cost of producing electricity from the crude, upgraded or refined liquid products by a variety of methods. The structure and scope of the program and the development of an energy self-sufficient flash pyrolysis model are detailed in the paper. The costs of producing crude and upgraded pyrolysis oil have been derived on an incremental basis and compared with the costs of the equivalent fossil fuels to demonstrate the effect of the proposed EEC carbon tax on fossil fuels.
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Short rotation coppice (SRC) is a promising plantation system because it provides inexpensive feedstock for biorefineries. This study investigated the conversion of 2-year-old first rotation SRC poplar into bio-oil via fast pyrolysis. The impact of leaf removal was studied by comparing the yields and compositions of bio-oil from noleaf coppice (NLC) and whole tree coppice (WTC). Leaf removal did not affect the bio-oil yield of SRC poplar samples (~55%), but lowered the char yield from 19.7% to 13.6% and increased the gas yield from 14.3% to 17.7%. The chemical compositions of bio-oils, char, and non-condensable gases obtained from WTC and NLC were different. Leaf removal changed the elemental composition of the bio-oil. The bio-oil from WTC had higher H (9.1%) and O (64.8%), but lower C (25.3%) than that from NLC. Consequently, leaf removal increased the higher heating value (HHV) of bio-oil by 2.1 MJ/kg (16.0%). Based on the results of the current research and our previous study, the energy recovery rate for producing liquid fuel via fast pyrolysis of SRC poplar samples (29.4~34.2%) is markedly higher than that obtained by biochemical conversion (15.6~25.5%).
Thesis
Ce travail s'inscrit dans le projet français de gazéification de la biomasse : le projet Gaya. C'est un vaste programme R&D partenarial coordonné par GDF SUEZ et soutenu par l'ADEME. L'objectif du projet Gaya est de développer une filière décentralisée de production de bio-méthane à partir de la gazéification de la biomasse selon un procédé thermochimique de deuxième génération. L'objectif de cette thèse est de réaliser un modèle de pyrolyse de biomasse représentatif des conditions du lit fluidisé de gazéification développé dans ce projet. Un pilote expérimental, le four à image, a été développé pour reproduire au mieux les conditions de chauffage d'un lit fluidisé à 850°C. Ce pilote permet de récupérer l'ensemble des produits de pyrolyse pour une analyse ultérieure. De là, les cinétiques des réactions de pyrolyse sont déterminées par modélisation des processus physico-chimiques et optimisation à partir des résultats expérimentaux. Le craquage des vapeurs primaires de pyrolyse éjectées de la particule de biomasse est étudié durant 300 millisecondes après leur éjection de la particule de biomasse. Ces expériences de craquage sont menées sur le montage expérimental combinant un réacteur tubulaire de pyrolyse et un réacteur parfaitement auto-agité de craquage. Le modèle développé permet de représenter la pyrolyse de la biomasse introduite dans le réacteur de gazéification
Article
Blast furnace gas ash (BFGA) contains high amounts of metal oxides such as Fe, Ca, Na and other active substances. In this paper, the possibility of BFGA as an effective and low-coat catalyst for the decomposition of biomass pyrolysis has been explored based on the high content of iron oxides for high yield of gas and low yield of pyrolysis oil from biomass. The effects of temperature and BFGA on the yield and properties of pyrolysis products were discussed. The variation of pyrolysis gas composition and low heating value of BFGA with temperature was analyzed. The results clearly indicate that adding BGFA to pine pellets can effectively decrease the liquid yield and significantly enhance the yield of pyrolysis gas. The production of H2 in pyrolysis gas can effectively increase by 5.16 % and 2.06 % respectively with the action of #1 BFGA and #2 BFGA compared with CK. It suggests that two kinds of BFGA can reduce the content of oxygen-containing functional groups and effectively degrade organic substances. This experimental results show that BFGA has the potential to be used as an effecient catalyst with excellent stability and realize the effective utilization of waste resources.
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The intriguing multi-scale fractal patterns ubiquitously observed in nature similarly emerge as fascinating structures in two-phase fluid flows of bio-oil breakup and atomization processes. High-resolution microscopy of the two-phase flows under 15 flow conditions (cases of different flow rates of the liquid and co-flowing air streams as well as different degrees of liquid preheating) reveal that the geometrical complexities evolve under the competing/combined action of the instability mechanisms such as Kelvin–Helmholtz, Rayleigh–Taylor and Rayleigh–Plateau leading into the transition from break-up to atomization. A thorough analysis of the higher order moments of statistics evaluated based on the probability density functions from 15,000 fractal dimension samples suggest that a single-value analysis is not sufficient to describe the complex reshaping mechanisms in two-phase flows. Consistently positive skewness of the statistics reveal the role of abrupt two-phase mechanisms such as liquid column rupture, ligament disintegration, liquid sheet bursting and droplet distortions in a hierarchical geometrical entanglement. Further, large kurtosis values at increased flow inertia are found associated with turbulence-induced intermittent geometrical reshaping. Interestingly, the proposed power-law correlation reveals that the global droplet size obtained from laser-diffraction measurements declines as the two-phase geometrical complexity increases.
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