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Liquid Products from the Continuous Flash Pyrolysis of Biomass

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Abstract

A bench-scale continuous flash pyrolysis unit using a fluidized bed at atmospheric pressure has been employed to investigate conditions for maximum organic liquid yields from various biomass materials. Liquid yields for poplar-aspen were reported previously, and this work describes results for the flash pyrolysis of maple, poplar bark, bagasse, peat, wheat straw, corn stover, and a crude commercial cellulose. Organic liquid yields of 60-70% mf can be obtained from hardwoods and bagasse, and 40-50% from agricultural residues. Peat and bark with lower cellulose content give lower yields. The effects of the addition of lime and of a nickel catalyst to the fluid bed are reported also. A rough correlation exists between has content and maximum organic liquid yield, but the liquid yield correlates better with the alpha-cellulose content of the biomass. General relationships valid over all reaction conditions appear to exist among the ratios of final decomposition products also, and this correlation is demonstrated for the yields of methane and carbon monoxide.

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... In addition the product distribution (char, liquids and non-condensable gases) depend on pyrolysis type and operating conditions [4] as depicted in Table 1. As mentioned above, in most cases the desired product is bio-oil since production of combustible gases is more efficient via gasification and if char is to be combusted then it is preferable to burn directly the entire biomass [5]. Thus, in this study the fast pyrolysis of bagasse was considered and examined. ...
... Over the past two decades, numerous reactor technologies have been examined and many processes have been tested and explored under different operating conditions. Scott et al. [5] have conducted a comprehensive study on pyrolysis reactor systems and concluded that 1) the bio-oil cooling demand will be minimum if the gas to feed ratio is minimized, 2) the reactor's temperature should remain as low as possible and 3) the pyrolyser should operate effectively on a small scale and at the same time have the potential to scale up easily. The bubbling fluidized bed (BFB) reactor appears to satisfy these criteria best and its construction and operation are now well established. ...
... As discussed previously, the pyrolysis reaction mechanism consists of five reactions; the biomass decomposition reactions (reactions 1-3 as depicted in Figure 1) which are highly endothermic (ΔH1-3 = 420 kJ/kg) and the tar cracking reactions (reactions [4][5] which are exothermic (ΔH4-5 = -40 kJ/kg) [27], hence the overall process is endothermic. Therefore, heat balance calculations are essential in order to define the required heat input. ...
Article
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This study deals with the comprehensive design of a biomass fast pyrolysis bubbling fluidising bed (BFB) reactor. The solid lignocellulosic residue of sugarcane industries, bagasse, was considered as feedstock. A detailed kinetic model was developed in order to simulate the behaviour of the pyrolyser and the kinetic parameters of bagasse pyrolysis were determined by fitting the model to appropriate experimental data. Subsequently, energy balances were applied in order to calculate the necessary heat of pyrolysis. This is 1.4 MJ/kg of bagasse and it is in accordance with relevant literature data. The model was, also, validated with respective experimental data and thereby it can be effectively used to simulate the performance of similar fast pyrolysis systems at various process conditions. Finally, the study concludes with the estimation of the capital and labour costs associated with the reactor and bio-oil storage units. In effect, this study exhaustively incorporates the basic mass, energy and economic calculations of the core unit of a fast pyrolysis plant. The latter will be fully designed in the near future as an expansion of the current model. Overall, the current research suggests and investigates the utilisation of a relatively abundant agricultural residue via fast pyrolysis for the production of bio-oil. The conditions that maximise the liquids yield is 525°C and residence time of 0.5s.
... After drying, the moisture content of poplar bark was 7.0 ± 0.5%, which is slightly lower than that reported in previous studies by Scott et al., who reported moisture contents of around 7.55%. [35]. The ash content was 5.8 ± 0.5%, much higher than that reported in the literature for poplar wood, which is usually in the 1.0-4.5% range [19,[35][36][37], but in the 5-10% range for different species of poplar bark, as reported in the literature [38]. ...
... [35]. The ash content was 5.8 ± 0.5%, much higher than that reported in the literature for poplar wood, which is usually in the 1.0-4.5% range [19,[35][36][37], but in the 5-10% range for different species of poplar bark, as reported in the literature [38]. ...
Article
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Lignocellulosic residues have the potential for obtaining high value-added products that could be better valorized if biorefinery strategies are adopted. The debarking of short-rotation crops yields important amounts of residues that are currently underexploited as low-grade fuel and could be a renewable source of phenolic compounds and other important phytochemicals. The isolation of these compounds can be carried out by different methods, but for attaining an integral valorization of barks, a preliminary extraction step for phytochemicals should be included. Using optimized extraction methods based on Soxhlet extraction can be effective for the isolation of phenolic compounds with antioxidant properties. In this study, poplar bark (Populus salicaceae) was used to obtain a series of extracts using five different solvents in a sequential extraction of 24 h each in a Soxhlet extractor. Selected solvents were put in contact with the bark sample raffinate following an increasing order of polarity: n-hexane, dichloromethane, ethyl acetate, methanol, and water. The oily residues of the extracts obtained after each extraction were further subjected to flash chromatography, and the fractions obtained were characterized by gas chromatography coupled with mass spectrometry (GC–MS). The total phenolic content (TPC) was determined using the Folin–Ciocalteu method, and the antioxidant activity (AOA) of the samples was evaluated in their reaction with the free radical 2,2-Diphenyl-picrylhydrazyl (DPPH method). Polar solvents allowed for higher individual extraction yields, with overall extraction yields at around 23% (dry, ash-free basis). Different compounds were identified, including hydrolyzable tannins, phenolic monomers such as catechol and vanillin, pentoses and hexoses, and other organic compounds such as long-chain alkanes, alcohols, and carboxylic acids, among others. An excellent correlation was found between TPC and antioxidant activity for the samples analyzed. The fractions obtained using methanol showed the highest phenolic content (608 μg of gallic acid equivalent (GAE)/mg) and the greatest antioxidant activity.
... The flash pyrolysis of biomass gives a maximum yield of liquid product. Furthermore, a medium heating value gas is generated and minor amounts of a reactive char, both of which are available as good-quality fuels [13]. In fast pyrolysis, biomass decomposes extremely quickly to produce mostly vapor and gas and some char. ...
... Cellulose is the principal source of carbohydrates and phenols are the basis of the bio-oil from lignin, while the bio-oil from hemicellulose mainly consists of acids, ketones, and aldehydes [22]. This study finds that date stones have a higher carbon and hydrogen content than peach stones [13]. In contrast, date stones have a lower oxygen content than peach stones. ...
Article
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Flash and fast pyrolysis of date palm stones (Phoenix dactylifera L.) was carried out in two different well-swept fixed-bed reactors under a nitrogen atmosphere and the effect of pyrolysis temperature (400–700 °C) and retention time on the product yields and compositions was investigated. The results show that fast or flash pyrolysis of date palm stones yields more bio-oil than char or non-condensable gases, especially at moderate temperatures. A maximum bio-oil yield was obtained at a pyrolysis temperature of 500 °C as 40.4% and 38.3% via the flash and fast pyrolysis methods, respectively. The functional groups, morphology, surface areas, and the C, H, N, and O and ash, moisture, volatile matter, and fixed carbon content of the chars were examined using Fourier transform infrared spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller, ultimate analysis devices, and proximate analysis, respectively. Chars with a maximum surface area were used for the adsorption of dyes from aqueous solutions and the adsorption capacity and the kinetics of the chars were determined. Bio-oil composition was investigated using gas chromatography/mass spectrometry and the content of C, H, N, and O was determined by ultimate analysis. The results show that the saturation adsorption capacities of char from flash pyrolysis are 100 and 70.9 mg/g for Methylene Blue and Acid Red 111, and that these values from fast pyrolysis are 105.2 and 97.1 mg/g for Methylene Blue and Acid Red 111, respectively. The bio-oils contain higher levels of oxygen than the chars. The heating values vary from 27.5 to 31.3 MJ/kg and from 24.9 to 28.2 MJ/kg for bio-oils and chars, respectively. In addition, the bio-oil products from the pyrolysis of date palm stones are predominantly fatty acids. The results indicate that the bio-oil products obtained by the pyrolysis of date palm stone may be used as fuel or for the production of chemicals, and the solid products used as fuel or adsorbents.
... Some gases are flammable and can be reused as fuel to generate heat. For this reason, many researchers have used NGC to generate heat in the reactor in order to reduce the production costs and to reduce emissions of NGC to the environment [44][45][46]. ...
... Firstly, the cost of producing heat with LPG was lower than using electric energy. Secondly, there was a greater heating power and higher stability to combust as compared to using charcoal & NCG [44][45][46] and charcoal [47,48]. Thirdly, the hot gas from combustion by LPG had a low oxygen composition in the flue gas, which can be directly used for the reactor in the pyrolysis process. ...
Article
This article presents a design study and the development of a low-cost production process for obtaining bio-oil from sugarcane bagasse by using a Circulating Fluidized Bed reactor (CFBr). The reactor had a diameter of 4 in. and a height of 4.5 m. In addition, sand with a diameter of 249 μm was used as the bed material. Sugarcane bagasse was used as the raw material for the bio-oil production. This bio-oil production system had a feed rate of between 18 and 45 kg/h. The outstanding design of this system consisted of the production of a bio-oil with high efficiency by using the following: (1) a gas combustor used in gas turbine engine, (2) a non-condensable gas recovery for use in the process, and (3) a feeder and pre-heat exchanger before condenser unit. The experiment was performed at a superficial velocity of between 5 and 7 m/s, with a bed temperature ranging from 440 to 520 °C, and with a bed inventory at 0.5 and 4.5 kg. From the experiment, it was found that this system could produce a maximum yield of bio-oil of 78.07 wt% at the bed temperature of at 480 °C. In addition, the superficial velocity, the bed inventory, and feed rate were 7 m/s, 4.5 kg, and 30 kg/h, respectively. The properties of the bio-oil, such as its heating value, viscosity, density, and pH were measured at 18,483 kJ/kg, 24.54 cSt, 1274 kg/m³, and 2.4, respectively. The chemical components of bio-oil were also investigated by GC–MS. In this system, the cold efficiency and total energy conversion to bio-oil production were 46.06% and 32.94%, respectively. From a cost analysis of bio-oil production, the results showed that the cost production was 0.353 $/l. In addition, the results revealed that the bed temperature, the solid re-circulating rate, and the suspension density had significantly and directly affected the yield of bio-oil production. Furthermore, the oxygen in the exhaust gas from the combustion system and the non-condensable gas from the process had been shown to have a direct effect upon the properties of the bio-oil.
... Since in the DFB gasifier at TU Wien, the pyrolysis happens in less than few seconds, only the correlations for the fast pyrolysis are considered. According to this research, there are correlations expressing: the yields of CH 4 and CO as reported in the work of Di Blasi et al. [30], or Scott et al. [31]; the yields of H 2 and CO; the yield of H 2 as a function of pyrolysis peak temperature [32], or the relation between the volatile products [33]; the yield of Char and its elemental composition as a function of pyrolysis peak temperature [34], also for secondary biomass [35] and dedicated cultivation [36]; the elemental composition of the Tars [37], and the thermal cracking [38] as well as the lower heating value in the function of temperature [39]. For the mentioned empirical correlations, the coefficient of the determination "R 2 " is always high enough to be taken as a reference for the further calculations. ...
... The same type of correlation exists also for the CHO content in the tar [31]. There is a weak relationship between the elemental composition of tar and pyrolysis temperature. ...
... To our best knowledge, only some papers [5][6][7][8][9][10][11][12][13] studied the properties and compositions of bio-oils from more than one different biomass type prepared using the same pyrolysis process to be able to reliably discuss the differences caused by biomass type exclusively. Just four of them analysed the individual volatile compounds in the prepared bio-oils by GC-MS; however, only two of them presented real quantitative results based on a proper calibration which is crucial for the drawing reliable conclusions [14]. ...
... cal wood bio-oil. Nevertheless, all the previously mentioned researchers [5][6][7][8][9][10][11][12][13] used pyrolysis units that are not suitable for mobile applications (fixed bed, fluidized bed and rotating cone) as they require fluidization and/or heat carrier medium. Moreover, all the mentioned pyrolysis units require energy-demanding grinding of biomass into small particles usually below 1 mm. ...
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.
... One of the best-known examples of using a fluidized bed reactor was Dynamotive, a company that resulted from the pioneering job conducted by the University of Waterloo. 11,12,146 In the design of most fluidized bed reactors in operation, the char is entrained A 10 ton/day mobile pyrolysis unit with a fluidized bed reactor has been developed by Agritherm at the University of Western Ontario (http://agri-therm.com). 16,42 An important feature of the design proposed by this company is its compactness, as the pyrolysis reactor is built using an annulus with a burner at the core to providing the energy needed for the pyrolysis process. ...
... 211,212 (11) Calculate the cross-sectional area and diameter of the reactor. 211 (12) In the case of fluidized bed reactors, calculate the volume of the expanded fluidized bed (sand and char particles). 211,213 (13) If designing a fluidized bed reactor, calculate the length and the of the free board. ...
Article
This paper provides a review of pyrolysis technologies, focusing on reactor designs and companies commercializing these technologies. The renewed interest in pyrolysis is driven by the potential to convert lignocellulosic materials into bio-oil and biochar and the use of these intermediates for the production of biofuels, biochemicals, and engineered biochars for environmental services. This review presents slow, intermediate, fast, and microwave pyrolysis as complementary technologies that share some commonalities in their designs. While slow pyrolysis technologies (traditional carbonization kilns) use wood trunks to produce char chunks for cooking, fast pyrolysis systems process small particles to maximize bio-oil yield. The realization of the environmental issues associated with the use of carbonization technologies and the technical difficulties of operating fast pyrolysis reactors using sand as the heating medium and large volumes of carrier gas, as well as the problems with refining the resulting highly oxygenated oils, are forcing the thermochemical conversion community to rethink the design and use of these reactors. Intermediate pyrolysis reactors (also known as converters) offer opportunities for the large-scale balanced production of char and bio-oil. The capacity of these reactors to process forest and agricultural wastes without much preprocessing is a clear advantage. Microwave pyrolysis is an option for modular small autonomous devices for solid waste management. Herein, the evolution of pyrolysis technology is presented from a historical perspective; thus, old and new innovative designs are discussed together.
... In addition the product distribution (char, liquids and noncondensable gases) depend on pyrolysis type and operating conditions [4] as depicted in Table 1. As mentioned above, in most cases the desired product is bio-oil since production of combustible gases is more efficient via gasification and if char is to be combusted then it is preferable to burn directly the entire biomass [5]. Thus, in this study the fast pyrolysis of bagasse was considered and examined. ...
... Over the past two decades, numerous reactor technologies have been examined and many processes have been tested and explored under different operating conditions. Scott et al. [5] have conducted a comprehensive study on pyrolysis reactor systems and concluded that 1) the bio-oil cooling demand will be minimum if the gas to feed ratio is minimized, 2) the reactor's temperature should remain as low as possible and 3) the pyrolyser should operate effectively on a small scale and at the same time have the potential to scale up easily. The bubbling fluidized bed (BFB) reactor appears to satisfy these criteria best and its construction and operation are now well established. ...
Conference Paper
Full-text available
This study deals with the comprehensive design and simulation of a biomass fast pyrolysis polygeneration plant by using Aspen plus software. The system generates bio-oil, hydrogen and electricity. A bubbling fluidising bed (BFB) reactor was considered to model the pyrolyser. The reactor model was developed in Matlab environment due to the insufficient kinetic options provided directly in the simulator. Overall, the process consists of five main steps, namely pretreatment unit, pyrolysis reactor, biooil recovery, hydrogen plant and char combustion. In effect, this study exhaustively incorporates the basic mass, energy and economic calculations of a second generation biorefinery. The solid lignocellulosic waste of sugarcane industries, bagasse, was considered as feedstock as it is a relatively abundant agricultural residue and does not provide competition with food and land. Bio-oil is produced at a rate of 650 kg per metric tonne of dry bagasse and at a production cost of 0.8 $/L. An excess of electricity of 15MW can be sold to the grid while A detailed kinetic model was developed in order to simulate the behaviour of the pyrolyser and the kinetic parameters of bagasse pyrolysis were determined by fitting the model to appropriate experimental data. Subsequently, energy balances were applied in order to calculate the necessary heat of pyrolysis. This is 1.4 MJ/kg of bagasse that is in accordance with relevant literature data. The model was, also, validated with respective experimental data and thereby it can be effectively used to simulate the performance of similar fast pyrolysis systems at various process conditions. Finally, the study concludes with the estimation of the capital and labour costs associated with the reactor and bio-oil storage units. In effect, this study exhaustively incorporates the basic mass, energy and economic calculations of the core unit of a fast pyrolysis plant. The latter will be fully designed in the near future as an expansion of the current model. Overall, the current research suggests and investigates the utilisation of a relatively abundant agricultural residue via fast pyrolysis for the production of bio-oil. The conditions that maximise the liquids yield is 525°C and residence time of 0.5s.
... In addition, the product distribution (char, liquids and non-condensable gases) depend on pyrolysis type and operating conditions [4], as depicted in Table 1. As mentioned above, in most cases the desired product is bio-oil since production of combustible gases is more efficient via gasification and, if char is to be combusted, then it is preferable to burn directly the entire biomass [5]. Thus, in this study the fast pyrolysis of bagasse was considered and examined. ...
... Over the past two decades, numerous reactor technologies have been examined and many processes tested and explored under different operating conditions. Scott et al. [5] conducted a comprehensive study on pyrolysis reactor systems and concluded that (1) the bio-oil cooling demand will be at the minimum if the gas-feed ratio is minimised; (2) the reactor's temperature should remain as low as possible; and (3) the pyrolyser should operate effectively on a small scale and at the same time have the potential to scale up easily. The bubbling fluidised bed (BFB) reactor appears to satisfy these criteria best and its construction and operation are now well-established. ...
Article
Full-text available
This study deals with the comprehensive design of a biomass fast pyrolysis bubbling fluidising bed (BFB) reactor. The solid lignocellulosic residue of sugarcane industries, bagasse, was considered as feedstock. A detailed kinetic model was developed in order to simulate the behaviour of the pyrolyser and the kinetic parameters of bagasse pyrolysis were determined by fitting the model to appropriate experimental data. Subsequently, energy balances were applied in order to calculate the necessary heat of pyrolysis. This is 1.4 MJ per kg of bagasse and it is in accordance with relevant literature data. The model was also validated against respective experimental outcomes and thereby it can be effectively used to simulate the performance of similar fast pyrolysis systems in various process conditions. The conditions that maximise the liquids yield are a temperature of 525 °C and a residence time of 0.5 s. Furthermore, dynamic sensitivity analysis was implemented to determine how sensitive the proposed model is to changes in the value of the kinetic parameters and subsequently to identify the most influential variables. Overall, the current research suggests and investigates the utilisation of a relatively abundant agricultural residue via fast pyrolysis for the production of bio-oil.
... The very first biomass pyrolysis was initially developed by the laboratory to process unit scale production in Canada and the United States during the 1980s [24][25][26]. Since then the technology has proved to be a promising alternative biofuel [27][28][29]. ...
Article
Full-text available
Bio-oils produced by biomass pyrolysis are substantially different from those produced by petroleum-based fuels and biodiesel. However, they could serve as valuable alternatives to fossil fuels to achieve carbon neutral future. The literature review indicates that the current use of bio-oils in gas turbines and compression-ignition (diesel) engines is limited due to problems associated with atomisation and combustion. The review also identifies the progress made in pyrolysis bio-oil spray combustion via standardisation of fuel properties, optimising atomisation and combustion, and understanding long-term reliability of engines. The key strategies that need to be adapted to efficiently atomise and combust bio-oils include, efficient atomisation techniques such as twin fluid atomisation, pressure atomisation and more advanced and novel effervescent atomisation, fuel and air preheating, flame stabilization using swrilers, and filtering the solid content from the pyrolysis oils. Once these strategies are implemented, bio-oils can enhance combustion efficiency and reduce greenhouse gas (GHG) emission. Overall, this study clearly indicates that pyrolysis bio-oils have the ability to substitute fossil fuels, but fuel injection problems need to be tackled in order to insure proper atomisation and combustion of the fuel.
... Depending on the selected pyrolysis temperature, the nature and composition of products may be changed. Most of the early studies were focused on flash pyrolysis at medium temperature to maximize bio-oil production (Scott et al., 1985;Piskorz et al., 1986;Yaman, 2004;Dominguez et al., 2005;Fonts et al., 2009;Zaimes et al., 2015). Aside the temperature, there are many parameters such as particle size, heating rate, residence time, and rotation speed in case of using a rotating reactor, which would affect the yield of the ultimate products along the process (Basu, 2010). ...
Article
This study explored the potential of high temperature pyrolysis for energy recovery from domestic sewage. It mainly defines optimum operating conditions to maximize syngas generation. A pyrolysis unit was operated in batch mode, at temperatures of 450, 600 and 850 °C, rotation speeds of 10, 40 and 60 Hz. The sludge had 6% moisture content; it contained 65% organic matter and involved a low calorific value of 13.535 kJ/kg dry matter. Pyrolysis at 850 °C and high rotation speed of 60 Hz yielded the highest conversion of sludge to syngas, with an average of 59% of the organic matter as syngas, 29% as tar and 12% as biochar. Pyrolysis enabled 74% of the energy recovery as syngas and tar. Continuous full-scale pyrolysis systems would further increase the syngas by recovering condensable gaseous products and/or recycling tar back into the pyrolysis unit. A unified approach for energy recovery management should equally consider what fraction of the energy contained in the wastewater was consumed and wasted before generating the sludge. Therefore, the adopted management scheme should also cover all design and operation parameters of the treatment plant, because this is how the energy is best conserved even before the sludge is generated.
... The availability of fossil fuels is limited, considering the fact that the demand for energy from fossil fuel is growing at high rate due to industrial development and is a major contributing factor to energy crisis. The energy crisis and fuel tension made biomass (forest residues) fast pyrolysis liquefaction a more important area of research and development [4][5][6]. In particular, the most advanced biomass pyrolysis processes, oriented to the production of an organic liquid fuel (referred to as bio-oil, bio-fuel-oil or bio-crude-oil, pyrolytic oil), appear to be very interesting for several possible energy application that can be envisaged for this fuel. ...
Article
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This paper evaluates the combustion properties of fuelwood and pyrolytic products from three selected sawmill wood residues-Gmelina arborea, Terminalia superba and Triplochiton scleroxylon. Pyrolysis experiments were performed at 450, 500 and 550°C. The percentage oil, pH, viscosities were considered. The highest yield of oil yield was at 550°C (45.70%) for Triplochiton scleroxylon out of the three sawmill wood residues. The analysis of variance conducted on pyrolytic oil produced at 450, 500 and 550°C for the G. arborea, and T. scleroxylon showed no significant difference but there were significant differences in the pH and viscosity of the pyrolytic liquid produced from selected wood species at the same conversion temperatures. The result showed the proximate analysis of the selected wood residues with the ash content (2.75, 2.61, and 3.57 %); fixed carbon (10.52, 12.07 and 10.23%); volatile (87.55, 85.48 and 86.46%) and heating value of 32792.75, 32691.56 and 32794.15 KJ/kg for Gmelina arborea, Terminalia superba and Triplochiton scleroxylon respectively. Proximate analysis results showed that the selected wood residues have good potential for domestic cooking and the characterized pyrolytic oil produced for biofuel production, most importantly for bioenergy sustainable system.
... According to statistics of availability of biomass waste, India have huge-amount of waste biomass that it can reduce the dependence of India on fossil fuel if properly processed, in addition to improving the economy of the country. Moreover, it helps to reduce CO 2 and other harmful emission in environment by maintaining the carbon neutrality or even carbon negativity [4][5][6][7]. In general, any lignocellulosic biomass consists of structures of lignin, cellulose and hemicellulose as the name lignocellulosic indicates though there may other components such as starch, proteins, etc. ...
Article
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Non-catalytic co-pyrolysis of Delonix Regia (DR) wood and Polyalthia Longifolia (PL) leaves and varying fractions of polypropylene (PP) has been carried out at 600 °C in a tubular reactor. The fractions of PP varied in order to have 0 wt%, 10 wt%, 30 wt% and 50 wt% of it in the feed while the composition of DR and PL maintained constant and equal to each other so that to study the effect of PP on co-pyrolysis of two lignocellulosic biomass waste materials. The feed materials, along with the products (bio-oil and bio-char) have been extensively characterized for their physicochemical and fuel properties. In addition, extensive advanced material characterization techniques such as Fourier transmission Infrared Spectroscope (FTIR), proton nuclear magnetic resonance (¹H NMR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), etc. have been utilized for analysis purposes. The properties of bio-oil reported in this work are of the organic phase only of the liquid product. The average calorific value of organic fraction of bio-oil is increasing from 22.556 MJ/kg to 34.06 MJ/kg with increasing wt.% of polypropylene (PP) in co-feed from 0 wt% to 50 wt% respectively, while the calorific value of bio-char is showing mixed trend. Density of organic phase decreases from 973 kg/m³ to 816 kg/m³ with increasing the fraction of PP, while pH display opposite trends i.e., increasing from 4.31 to 4.97 which are close to commercial fuel properties. FTIR confirm the presence of functional groups of alkanes, aromatics, alcohols, phenols, aliphatic, ketone, ethers, etc. in organic fraction of bio-oil; and also confirmed by proton NMR. Further it is also confirmed that fraction of alkanes and aliphatic in bio-oil samples increases with PP fraction in the co-feed. The main finding of this work indicates that the fraction of PP in co-feed improved the physicochemical, chemical and fuel potential of the organic phase of liquid product. However, the trend of yield of organic fraction of liquid is not as expected and the reason could be the presence of leaves of PL because often the yield of liquid product is very low when leafy biomass used as feed.
... This pilot plant was designed to produce a low cost production for obtaining pyrolysis oil. The process of production line was modified to a new schematic process from many previous literatures which it was not duplicate with other systems (Onay et al., 2001;Onay, 2007;Sensoz and Angin, 2008;Jung et al., 2008;Duanguppama et al., 2016;Stamatov et al., 2006;Morales et al., 2014;Treedet and Suntivarakorn, 2011;Asadullah et al., 2008;Cai and Liu, 2016;Cai et al., 2018;Akarregi et al., 2013;Boukis et al., 2001;Antonelli, 1989;Trebbi et al., 1997;Dai et al., 2001;Scott et al., 1985;McAllister, 1997;Lappas et al., 2002;Maniatis et al., 1993;Knight et al., 1982;Cuevas et al., 1994). The features of this particular pilot plant was that the CFBr was heated using the exhaust gas from a can combustor and that LPG was used as the fuel to generate the heat. ...
Article
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This article focused on production cost of pyrolysis oil production of Napier Grass in Circulating Fluidized Bed Reactor (CFBr) which sand was used as bed material. The Napier grass was converted to pyrolysis oil by using fast pyrolysis process. The reactor temperature, superficial velocity (Uf) and feed rate of feedstock were adjusted in order to find the best condition of this experiment, and the Quadratic Response Model was used to predict the yield of pyrolysis oil and the optimum condition coupled with the experiment. From a results of this experiment, it was found that the maximum pyrolysis oil production was 36.93 wt% at 480 ºC of bed temperature, 7 m/s of superficial velocity and 60 kg/hr of feed rate, while the result from the Quadratic Response Model indicated that the maximum pyrolysis oil production was 32.97 wt%. From the analysis of properties of pyrolysis oil, results showed that heating value, density, viscosity, pH and water content were 19.79 MJ/kg, 1,274 kg/m 2.32 cSt, 2.3 and 48.15 wt%, respectively, and the ultimate analysis was also determined. From the analysis of the efficiency of energy conversion, it was concluded that the value of cold efficiency and total energy conversion to pyrolysis oil in this system were 24.88% and 19.77%, respectively. The greatest energy consumption in this system was made by the energy from the heating process. Furthermore, from the calculation result of production cost in this study, it was concluded that a production cost of pyrolysis oil was 0.481 $/liter or 9.88 $/GJ at the 75 kg/hr of feed rate. Keywords: Napier grass, Fast pyrolysis, Pyrolysis oil, CFBr
... It contains mostly C (85-95%) with a small amount of H and O. Therefore, to overcome the cited limitation of ASPEN plus, it was decided to model the Char as pure carbon (homogeneous compound) instead of a heterogeneous nonconventional compound in the simulation (see the modelling assumptions cited before). The same type of correlation exists also for the CHO content in the tar [17,18]. Contrasting with the behaviour of char, there is a weak relationship between the elemental composition of tar and pyrolysis temperature. ...
Conference Paper
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Biomass energy conversion is a reliable way to produce energy and chemical products if compared with other renewable sources such as wind, solar and wave which have intermittent nature. Amongst different methods of converting biomass to energy, the thermo-chemical process of steam gasification is an outstanding way, since it enables a subsequent poly-generation process that can lead to production of heat, electricity, synthetic natural gas and synthetic chemicals such as methanol, Fischer-Tropsch diesel, gasoline and kerosene. The modelling of biomass gasification enables the optimization of the process designs, but it is a challenge due to its high complexity. Here, a new approach is used to simulate a 100 kW dual fluidized bed gasifier. Detailed pyrolysis modelling is a key factor of this approach and enables more accurate results. The results have been validated by experiments conducted with softwood pellets as fuel and fresh olivine sand as bed material. The impact of the gasifier temperature variation on the final product gas composition is measured in the experiments and implemented in the simulation to have a better insight on the pyrolysis process, the char heterogeneous reactions as well as the deviation from equilibrium of the water gas-shift reaction.
... The products obtained during the reaction are collected separately and also treated to purify. Like electrostatic precipitators are used in most of the cases for capturing pyrolysis aerosols, but their operations are observed to be tricky and also expensive (Scott et al. 1985). According to Demirbas (2000a, b), products from pyrolysis not only depend on the temperature or the reactor bed at which they had been subjected but also on the water present inside the biomass that can influence the liquid phase product and contributes in extracting some water-soluble products from the gas and tar phases and leads to huge decrease in gaseous and solid products (Arni 2010). ...
Chapter
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Increasing global energy demand is being substantially contributed by the bioenergy sector. For the rural communities, bioenergy provides opportunities for social and economic development by improving the waste and other resource management. The contribution of bioenergy proves to be significant in terms of maintaining social, economic as well as environmental health, ensuring energy security. Biomass, when converted to bioenergy, may undergo different suitable processes. Thermochemical conversions are no exception. The process technologies include combustion, torrefaction, pyrolysis, and gasification. All these processes having the common backbone of thermal decomposition are optimized by different factors and yield specific products of different states such as solid, liquid, and gases. The characteristics of generic types of reactors used to carry out such processes are described with their special features, advantages, and disadvantages. Though researches have called for three types of possible biomass for conversion such as lipid, sugar/starch, and lignocellulose in the present chapter, conversion of lignocellulosic biomass feedstock is focused. It has been discussed how the variations in composition of biomass at optimized process flow differ the quality and quantity of potential product yields.
... In recent years the consumption of energy has increased and due to what conventional fossil fuels have been depleted with the increase of populations and economy, it is necessary to explore renewable energies and ensure sustainable development. In this sense, biomass seems to be a clean option, since it contains small amounts of sulfur, nitrogen and ash, which generate less emissions of SO 2 , NO x and soot than conventional fossil fuels (Bridgwater and Peacocke 2000;Czernik and Bridgwater 2004;Scott et al. 1985;Zhang et al. 2007). ...
Article
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The biomass conversion technologies, especially different types of pyrolysis, have been intensively studied to improve biomass energy transformation suggesting a low impact on the environment. In particular, fast pyrolysis of biomass is considered to be a thermal process in which the starting material is converted to bio-oil, char and gas products. In this work, volatile organic compounds (VOCs) of the gaseous fraction of peanut shells fast pyrolysis were collected and identified at atmospheric pressure. Aromatic compounds, hydrocarbons, furans and other oxygenated compounds were identified using solid phase microextraction (SPME) and gas chromatography coupled to mass spectrometry (CG-MS) as a detection system. The composition of volatiles was analyzed and compared with the constituents of liquid fraction for comparative purposes. Atmospheric implications of the main compounds identified in the gases fraction were assessed by determining tropospheric lifetimes of the VOCs identified and its impact on environment at the local, regional or global scale.
... , magnesium carbonate (MgCO3), dolomite (CaCO3·MgCO3), and olivine are abundant and of low cost. Their calcined versions have high catalytic activities for tar elimination and catalytic upgrading[225,[325][326][327][328][329]. Alkaline-earth metal oxides such as MgO and MgO-based mixed oxides are among the most promising solid base catalysts[159,292,317,325,330,331]. ...
Article
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Direct catalytic upgrading of biomass-derived fast pyrolysis vapors can occur in different process configurations, under either inert or hydrogen-containing atmospheres. This review summarizes the myriad of different catalysts studied, and benchmarks their deoxygenation performance by also taking into account the resulting decrease in bio-oil yield compared to a thermal pyrolysis oil. Generally, catalyst modifications aim at either improving the initial selectivity of the catalyst to more desirable oxygen-free hydrocarbons, and/or to improve the catalysts’ stability against deactivation by coking. Optimizing pore structure and acid site density/distribution of solid acid catalysts can slow down deactivation and prolong activity. Basic catalysts such as MgO and Na2O/gamma-Al2O3 are excellent ketonization catalysts favoring oxygen removal via decarboxylation, whereas solid acid catalysts such as zeolites primarily favor decarbonylation and dehydration. Basic catalysts can therefore produce bio-oils with higher H/C ratios. However, since their coke formation per surface area is higher, compared to microporous HZSM-5 zeolite, pre-coking (or imperfect regeneration) of these basic catalysts and operating for longer time-on-stream can be approaches to improve the oil yield. In-line vapor-phase upgrading with a dual bed comprising a solid acid catalyst followed by a basic catalyst active in ketonization and aldol condensation further improves deoxygenation, while maintaining high bio-oil carbon recovery. Also low-cost catalysts such as iron-rich red mud have deoxygenation activity. An improved bio-oil carbon recovery— compared at similar level of oxygen removal—can be obtained when changing from an inert atmosphere to a hydrogen-containing atmosphere and using an effective hydrodeoxygenation (HDO) catalyst. To keep costs low, this can be conducted at near-atmospheric pressure conditions. Pt/TiO2 and MoO3/TiO2 showed high activity and reduced coke formation. Stable performance has been demonstrated using Pt/TiO2 for 100+ reaction/regeneration cycles with woody biomass feedstock. If future works can demonstrate the same durability for lower cost biomass containing higher contents of ash, N, and S, this would considerably boost the commercial viability of near atmospheric pressure HDO. Further research should be directed into testing the durability of lower cost HDO catalysts such as MoO3/TiO2 and further improving the activity and stability of lower cost catalysts.
... The nonprioritization of hemicellulose is because of the fact that its degradation causes the formation of by-products which are inhibitory in nature to the hydrolytic enzymes. The production of bioethanol from lignocellulosic Scott et al. (1985) biomass can be divided into three basic furcation, that is, pretreatment, enzymatic hydrolysis, and fermentation. ...
... As a result, it is imperative to search for models that could predict product distribution, including primary and secondary biomass pyrolysis processes. Researchers formulated models to include the primary' reactions products as secondary reactions to produces materials similar to the direct products, i.e., gas, tar, and char, through cracking and polymerization reactions (Thurner, 1981;Bradbury, et al., 1979;Scott, et al., 1985;Agrawal, 1988). Several kinetic schemes have been proposed for combining primary degradation of biomass and secondary decomposition of volatile products (higher molecular weight hydrocarbons). ...
Article
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Modeling of biomass pyrolysis kinetics is an essential step towards reactors design for energy production. Determination of the activation energy, frequency factor, and order of the reaction is necessary for the design procedure. Coats and Redfern's work using the TGA data to estimate these parameters was the cornerstone for modeling. There are two significant problems with biomass modeling, the first is the determination of the kinetic triplet (Activation energy, Frequency factor, and the order of reaction), and the second is the quantitative analysis of products distribution. Methods used in modeling are either One-step or Multistep methods. The one-step techniques allow the determination of kinetic triplet but fail to predict the product distribution, whereas multistep processes indicate the product's distribution but challenging to estimate the parameters. Kissinger, Coats, and Redfern, KAS, FWO, Friedman are one-step methods that have been used to estimate the kinetic parameters. In this work, after testing more than 500 data points accessed from different literature sources for coal, oil shale, solid materials, and biomass pyrolysis using one-step global method, it was found that the activation energy generated by KAS or FWO methods are related as in the following equations: 𝐸𝐾𝐴𝑆 = 0.9629 ∗ 𝐸𝐹𝑊𝑂 + 8.85, with R² =0.9945 or 𝐸𝐹𝑊𝑂 = 1.0328 ∗ 𝐸𝐾𝐴𝑆 − 8.0969 with R2= 0.9945. The multistep kinetic models employed the Distributed Activation Energy Model (DAEM) using Gaussian distribution, which suffers from symmetry, other distributions such as Weibull, and logistic has been used. These multistep kinetic models account for parallel/series and complex, primary and secondary biomass reactions by force-fitting the activation energy values. The frequency factor is assumed constant for the whole range of activation energy. Network models have been used to account for heat and mass transfer (diffusional effects), where the one-step and multistep could not account for these limitations. Three network models are available, the Bio-CPD (Chemical Percolation Devolatilization) model, Bio-FLASHCHAIN, and the Bio-FGDVC (Functional Group Depolymerization Vaporization Crosslinking models). These models tried to predict the product distributions of the biomass pyrolysis process
... Flash pyrolysis process is essential to know the devolatilization characteristics and to maximize the evolved volatile gases in high heating rate with shorter duration. The process was previously studied in several works [26][27][28] in different reaction furnaces to be probably reproduced the reaction conditions closer to those encountered as one of the processes in practical fluidized bed gasification. Fluidized bed gasification could be attributed a co-relationship between (1) flash pyrolysis and (2) pyrolysis gas partial combustion as it is generally known that the gasification reaction in FBG is completed immediately. ...
Article
Fluidized bed gasifiers (FBGs) and gas engines (GEs) could be available as waste-to-energy technology, because most small- and medium-scale municipal solid waste treatment plants have low electricity generation efficiencies. As feedstock composition vary widely based on regional characteristics, clarifying the relationship between gas and tar generation behaviors and feedstock is useful for the design of the GE generation process to predict gas and tar yields and compositions. To understand the synergistic effect of feedstock characteristics in fluidized bed gasification, flash pyrolysis of wood pellet, polyethylene, and polypropylene at 900 °C was conducted. Yields and compositions of gasses and tar from single and co-pyrolysis were investigated. The results reveal that co-pyrolysis increases the gas yield because of oxygenates and moisture present in the wood pellet. Tar yields found to decrease while polycyclic aromatic hydrocarbons (PAHs) are not reduced even during co-pyrolysis. That is because most chain hydrocarbons of tar are converted to CmHn gases and PAHs.
... Many researchers have been reported some biomass waste were converted to bio-oil [2,3,1,4]. The pyrolysis process is the thermochemical that is commonly used to convert biomass into bio-char and bio oil at temperature ranges of 300-600 o C [5,6]. In common, a lower warming amount is more suitable for the manufacture of more char, while a higher warming amount is valuable to the manufacture of more bio-oil [7,8,9]. ...
Conference Paper
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The residues from the wood industry are the main contributors to biomass waste in Indonesia. The conventional pyrolysis process, which needs a large energy as well as to produce various toxic chemical to the environment. Therefore, a pyrolysis unit on the laboratory scale was designed that can be a good alternative to achieve zero-waste and low energy cost. In this paper attempts to discuss design and system of pyrolysis reactor to produce bio-oil and bio-char simultaneously.
... Depending on the selected pyrolysis temperature, the nature and composition of products may be changed. Most of the early studies were focused on flash pyrolysis at medium temperature to maximize bio-oil production (Scott et al., 1985;Piskorz et al., 1986;Yaman, 2004;Dominguez et al., 2005;Fonts et al., 2009;Zaimes et al., 2015). Aside the temperature, there are many parameters such as particle size, heating rate, residence time, and rotation speed in case of using a rotating reactor, which would affect the yield of the ultimate products along the process (Basu, 2010). ...
Article
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This study explored the potential of high temperature pyrolysis for energy recovery from domestic sewage. It mainly defines optimum operating conditions to maximize syngas generation. A pyrolysis unit was operated in batch mode, at temperatures of 450, 600 and 850 °C, rotation speeds of 10, 40 and 60 Hz. The sludge had 6% moisture content; it contained 65% organic matter and involved a low calorific value of 13.535 kJ/kg dry matter. Pyrolysis at 850 °C and high rotation speed of 60 Hz yielded the highest conversion of sludge to syngas, with an average of 59% of the organic matter as syngas, 29% as tar and 12% as biochar. Pyrolysis enabled 74% of the energy recovery as syngas and tar. Continuous full-scale pyrolysis systems would further increase the syngas by recovering condensable gaseous products and/or recycling tar back into the pyrolysis unit. A unified approach for energy recovery management should equally consider what fraction of the energy contained in the wastewater was consumed and wasted before generating the sludge. Therefore, the adopted management scheme should also cover all design and operation parameters of the treatment plant, because this is how the energy is best conserved even before the sludge is generated.
... Therefore, in order to facilitate methane production from aqueous phase of pyrolysis oil during anaerobic digestion process, the amount of Hydroxyacetaldehyde (HAA) should be minimized. The pretreatment methods can not only reduce the formation of HAA but can also increase the overall yield of bio-oil [21,22]. HAA is a common low molecular weight organic compound produced from fragmentation of cellulose during pyrolysis, which has been identified as one of the most toxic compounds for fermentation micro-organisms found in bio-oils [20,23]. ...
Article
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The aim of this work was to evaluate biomethane production by anaerobic digestion using aqueous phase from Fast Pyrolysis of Douglas Fir Wood as substrate. The effect of biomass acid treatment and condensation temperature on the bio-oil chemical composition and aqueous phase separation with a fractional condensation system coupled to Auger reactor during pyrolysis at 500 °C was reported. As the first condenser temperature was augmented from 40 and 80 °C, the bio-oil yield obtained decreased from 30 to 16 wt% and the aqueous phase yield in the second condenser (kept at 25 °C) increased from 27 till 37 wt%. When the untreated biomass was pyrolyzed, the aqueous phase collected in the second condenser (at the first condenser operated at 80 °C) was anaerobically digested at 100 ppm for 400 h results in 31.3 NmL of CH4/batch. However, the best result was attained after washed biomass with acetic acid (10%) previously to fast pyrolysis, obtaining 86.8 NmL of CH4/batch using just 10 ppm, perhaps due to halved of formed hydroxyacetaldehyde and estimated levoglucosan content increases by more than three times at this condition. Thus, the attained results confirmed the viability of the adopted strategy to improve the anaerobic digestion of the aqueous phase obtained by fractional condensation systems for biomethane production.
... Modern technology for processing and burning solid fuels opens up wide prospects for its effective use in various fields of industry, energy generation, and agriculture. Along with traditional grate firing [1], widespread are the methods of arranging the combustion process in a fluidized bed [2], pulverized burning in order to study kinetic parameters [3][4][5], in laminar [6,7] and turbulent [8,9] jets; the methods of gasification [10,11], pyrolysis [12,13], and creating water-coal fuel [14][15][16][17] are being used extensively. ...
Article
Bidirectional (or countercurrent) vortex combustors are some of the most promising vortex-flow devices in terms of the fuel and oxidizer mixing efficiency, the combustion efficiency, the emission characteristics, and the combustion stability. This paper suggests a new arrangement principle for combustion of solid pulverized peat in conditions of vortex countercurrent flow which has never been studied earlier; we developed a combustion unit implementing this principle and carried out a numerical analysis of the combustion process with various operating parameters. The calculation results confirmed the possibility of combustion within a wide range of parameters and showed that varying the air-fuel equivalence ratio from λ = 0.5 to λ = 5.05 results in significant change in both the structure of the limited vortex flow and the distribution of total pressure and temperature, as well as the averaged volume concentration of fuel particles. We calculated the boundaries of lean and rich flame blowouts where the gas-dynamic flow loses its stability and the toroidal vortex is disrupted. At the same time, secondary vortex structures are formed throughout the combustor volume.
... One promising strategy is to produce transportation fuels from lignin biomass waste. [2][3][4][5] Converting the oxygenated aromatic compounds in water that come from fast pyrolysis of lignin (i.e., bio-oil) to transportation fuels or chemical precursors requires aqueous-phase catalytic or electrocatalytic hydrogenation and hydrodeoxygenation, 6 typically rate-limited on metals by surface reactions. To improve the kinetics of these and other aqueousphase catalytic reactions, an understanding of the effect of water (or solvent) on organic adsorption is critical, because adsorption energies can determine coverages and alter activation barriers. ...
Article
Accurately predicting adsorption energies of oxygenated aromatic and organic molecules on metal catalysts in the aqueous phase is challenging despite its relevance to many catalytic reactions such as biomass hydrogenation and hydrodeoxygenation. Here we report the aqueous-phase adsorption enthalpies and free energies of phenol, benzaldehyde, furfural, benzyl alcohol, and cyclohexanol on polycrystalline Pt and Rh determined via experimental isotherms and density functional theory modeling. The experimental aqueous heats of adsorption for all organics are ~50-250 kJ mol −1 lower than calculated gas-phase heats of adsorption, with a larger decrease for Rh compared with Pt. Unlike in gas phase, phenol and other aromatic organics adsorb with similar strength on Pt and Rh in aqueous phase. The similar aqueous adsorption strength of phenol and benzaldehyde on Pt and Rh explains their comparable aqueous-phase hydrogenation activities, which are rate limited by a Langmuir-Hinshelwood surface reaction. A widely used implicit solvation model largely overpredicts the heats of adsorption for all organics compared with experimental measurements. However, accounting for the enthalpic penalty of displacing multiple water molecules upon organic adsorption using a bond-additivity model gives much closer agreement between experimental measurements and predicted heats of adsorption. This bond-additivity model explains that the similar adsorption strength of organics on Pt and Rh in aqueous phase is due to the stronger adhesion of water to Rh than Pt, which offsets the stronger gas-phase organic adsorption energy on Rh. The data reported herein also provides a valuable resource for benchmarking methods for predicting aqueous-phase adsorption energies of C5/C6 organics on metal surfaces.
... FasP is the process with thermal decomposition under a moderate temperature of 300 -700 in the reaction zone without oxygen (Bridgwater and Peacocke, 1999;Scott and Piskorz, 1984). The reactor configurations include bubbling fluid beds (Robson, 2001;Scott et al., 1985), circulating and transported beds (Graham et al., 1988;Wegenaar et al., 2000), cyclonic reactors (Czernik et al., 1995;Diebold and Scahill, 1988), and ablative reactors (Peacocke and Bridgwater, 1996), which play an important role in this process to ensure the production. The FasP process is showed in Fig. 2. FasP is applied to decompose the waste into bio-oil. ...
Article
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The objective of this paper is to establish the state of knowledge on fast pyrolysis of bio-oil and bio-asphalt binder and to facilitate efforts in improving the overall performance of bio-asphalt and maximizing its road application. On the basis of reviewing the relevant literature recently, the fast pyrolysis (FasP) preparation process of bio-oil and its main properties, the preparation process of bio-asphalt and its performance and the application of bio-asphalt have been summarized. Due to the variations in raw materials, the adopted methods of FasP to prepare bio-oil could be different, and the properties of bio-oil from different sources are also different. At present, the plant-based bio-oil (mainly derived from wood waste and sawdust) has been widely used to prepare the bio-asphalt. Research on the low-temperature flexibility, high-temperature rheology, workability and other performance of biological asphalt showed that the workability and high-temperature performance of most asphalt are improved after adding bio-oil. However, the low-temperature performance is found to relatively reduce. Also, with regards to its application as a rejuvenator, bio-oil can considerably rejuvenate the aged asphalt’s mixture performance. By far, most of research on bio-asphalt is still focused on the performance of bio-asphalt binder in the laboratory; its application in practical road engineering is still to be examined. This review also provides an outlook for the future, for example, establishing an integrated preparation process from bio-oil to bio-asphalt, and evaluating the properties of bio-asphalt by new standards.
... Dry biomass (Durian lai peel waste) was carbonized using slow pyrolysis. This method has been developed by some investigators [7][8][9]. Dry biomass was placed in electrically heated furnace at temperature of 400 o C for 30 min as shown in the Figure 2. After 30 min, the furnace was cooled down to room temperature, and then the particle size of the charcoal is reduced by mortar, we selected particle size of 2.00 mm as optimum value (obtained from the preliminary study). ...
Conference Paper
Briquettes are widely used as a renewable energy to solve the problems of excessive use of wood as fuel. However, the performance of briquettes depends on the types of pyrolysis and the nature of binders used during the preparation. Their performances are related to problems such as low yield and energy content, but can be significantly improved with the use of adhesives in the right compositions. In this work, we investigated the effect starch binders compositions on the quality of briquettes from the pyrolysis of Durian lai peel (Durio kutejensis Becc). The briquettes were prepared from Durian peel charcoal by adding starch as a binder at various concentrations of 3%, 4%,5%, and 6% (w/w). Subsequently, analysis of moisture content, volatile matter ash content, and calorific value were found that the best quality obtained was form the briquette with binder concentration of 3 % (w/w).
... As observed by Raveendran et al., AAEM species influenced both the pyrolysis behaviors and the product yields strongly [9]. Scott et al. first conducted research into the effect of lime (CaO) on liquid products of biomass pyrolysis [11]. Nowakowski et al. suggested that the presence of potassium made the char yields increase from the short rotation willow coppice pyrolysis [12]. ...
Article
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The effects of potassium chloride (KCl) on the pyrolysis of medium density fiberboard (MDF) were investigated by using thermogravimetry/Fourier-transfer infrared spectroscopy (TG-FTIR). Five MDF samples treated with different KCl concentrations (0%, 0.5%, 1%, 2% and 3%) were heated with a heating rate of 20 °C/min. The thermogravimetry (TG) results showed that KCl caused the primary pyrolysis stage towards lower temperatures. The FTIR results indicated that with the concentrations of KCl, the formation of CH4 and C=O functional groups decreased while the formation of CO2 and CO increased. To figure out the reason for the observed phenomena, the kinetic parameters in primary pyrolysis and the secondary charring reaction were estimated by a differential evolution (DE) optimization algorithm. The prediction indicated that KCl shifted the initial degradation temperature of each component of MDF towards a lower temperature. Char and gas yields increased with the concentration of KCl, whereas the tar yield reduced. The changes in activation energies revealed that KCl played a catalyst role in the reaction of resin, hemicellulose and cellulose in primary pyrolysis. For lignin, KCl had little effect. In the secondary charring reaction, KCl apparently promoted the reaction of tar. The catalytic effect of KCl on MDF pyrolysis was the combination of primary pyrolysis and the secondary charring reaction. Finally, the optimal catalytic concentration for KCl on MDF pyrolysis was analyzed.
... 74 However, the detailed chemistry of the reaction mechanism is not considered in global kinetic models as they contain only primary reactions. Therefore, the kinetic models were modified to consider secondary reactions also 79 which include gas formation from tar decomposition and tar polymerization reactions to give char as a byproduct. 80 Another model is a multireaction model or competing and parallel reaction model. ...
Article
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Biomass pyrolysis is a thermochemical conversion process that undergoes a complex set of concurrent and competitive reactions in oxygen-depleted conditions. A considerable amount of the literature uses lumped kinetic approaches to predict pyrolysis products. Despite the prolonged studies, the science of pyrolysis chemistry and models' capability to simulate the exact conversion phenomenon has unraveled yet. In this review, an initiative was made by compiling existing mathematical models for biomass pyrolysis viz., lumped and distributed kinetic models, particle, and reactor models. An absolute analysis of computational fluid dynamics (CFD), artificial neural network (ANN), and ASPEN Plus models was also conducted. It was observed that the coupling of distributed kinetic models with CFD provides a better understanding of the hydrodynamic reaction of particles under reactive flow with the influence on reactor performance and predicts exact product yield. Furthermore, the pros and cons of each modeling technique are also highlighted individually. Finally, considering the future perspective of biomass pyrolysis with respect to the modeling approach, suggestions have been incorporated.
... 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.
Article
Cellulosic biorefinery stillage contains waste water with dissolved unutilized fermentable sugars and, mainly, lignin of the biomass. Currently, the best use of this lignin is through direct combustion to supply industrial process energy; however, fast pyrolysis has recently attracted researcher's interest as it has the potential to convert lignin into bio-oil and bio-char. It is essential that these alternative routes be thoroughly analyzed for their techno-economic feasibilities and bottlenecks, which was the main objective of this study. Stillage from a cellulosic biorefinery of a113.5 million liters per year (30 million gallons per year) butanol production facility was considered in this study. Experimental and modeling data for both fast pyrolysis and direct combustion systems were gathered from recent publications and used for analysis. Modeling software, SuperPro Designer, was used to develop process models and economic analyses of both systems. The estimated stillage processing cost ($/l butanol produced) of a direct combustion system and fast pyrolysis system were found to be 0.15 and 0.17, respectively, including byproducts credits. Plant size, anaerobic digester retention time, the moisture content of solid stillage, turbine and boiler efficiencies, and cost of waste treatment chemicals were the most sensitive input parameters. At the present state of these technologies, direct combustion is a more economically feasible option than fast pyrolysis; however, both could be of interest to commercial cellulosic biorefineries, interested in lignin utilization alternatives, due to the marginal difference in stillage utilization costs.
Article
The pyrolytic volatiles released from a converting biomass particle are investigated in this work through laboratorial fluidized bed experiments simulating conditions typical of large-scale gasifiers. Two types of wood (eucalyptus and pine) and two types of pellets (forest residues and wood) with particles of 6-8mm in diameter are fed over the hot bubbling bed at temperatures within 600-975°C. The resultant major pyrolytic products (char, soot, liquids and permanent gas) are collected to verify the overall mass balance, and the composition of the permanent gas is resolved in C3H8, C2H6, C2H4, CH4, CO2, CO, and H2. Primary pyrolysis of the parent fuel particles is essentially complete at 600°C and further increase of the temperature mainly leads to a progressive change in the composition of the volatile gas mixture. Although the gas release does not attain thermodynamic equilibrium under the conditions tested, our results show that the yields of CO2 and light hydrocarbons go through maxima as temperature increases to give rise to CO and H2 as the preferable species at high temperatures. As a whole, the gas composition evolves in such a way that the corresponding lower heating value steadily increases with temperature increase, from about 11MJ/kg at 600°C to above 17MJ/kg at 950°C. Furthermore, the yields of key gas species were found well correlated to each other (C2H4 vs. CH4, CH4 vs. CO and H2 vs. CO), with the relation between the yields of H2 and CO being slightly dependent on the composition of fuel.
Article
The use of renewable energy sources is becoming increasingly necessary. Biomass is considered to have potential to be used as an alternative energy source. The bio-oil obtained of biomass pyrolysis is used as fuels and chemicals products. The yield and composition of pyrolysis oil depend on biomass composition and operating parameters of the process. This review was written with a focus on parameters that influence the process, such as temperature, reaction time, heating rate, gas flow rate, feed rate, particle size and biomass composition and discusses the effect of these parameters on the yield and quality of bio-oil. Besides that, a database with different types of biomass analyzed under different operating conditions that interfere with the pyrolysis process was obtained from 206 research on the pyrolysis process found in the literature. This database can be used for a better understanding of how the composition of the biomass and the parameters of the pyrolysis process interfere with the composition and yield of the obtained products.
Chapter
A thorough assessment has been made of the characteristics of bio-oil from fast pyrolysis of biomass. Fast pyrolysis uniquely gives high yields of a homogenous mobile liquid for direct use for heat and power and indirect use for biofuels and green chemicals. An improved understanding of the significance of the different aspects of quality of bio-oil helps to establish standards and key quality requirements which help to define limitations for use. An appreciation of the potential for bio-oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity in studying the science and technology of fast pyrolysis with increased emphasis on quality improvement. This increased activity is evident in North America, Europe and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the continued limited industrial development and deployment of fast pyrolysis that are necessary to provide the basic bio-oil raw material for the development and exploitation of applications.
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The rising cost of fossil fuel and environmental concern has motivated the scientific committee to research on alternative sustainable solution for energy and economic development. One of such sustainable energy resource is biomass, which is abundant, clean and carbon neutral. Agricultural residue which is abundant and causing problems of storage being wasted without using in any form energy source. The present study highlights utilization of residue biomass to useful form of energy using different thermochemical conversion technologies. This study is presented as a technical review cum analysis study which has been done on various common agricultural wastes for their Thermochemical conversion technologies which includes combustion, gasification, pyrolysis, torrefaction and liquefaction. The common agricultural wastes that are being taken for study are coconut shell, rice husk, corn cobs, cotton stalk, groundnut shell, cotton, sugarcane (bagasse). In Combustion process, the yield of gaseous product is around 50%, which can be utilized for combined heat and power production. In the combustion process, drawbacks are discussed and specified. It was observed that suitable combustor can be implemented for improving its oxidative characteristics so that the product gas yield can be increased for high quality steam production. In Gasification process, the biomass is partially oxidized to give a raw product gas or syngas which can be used in IC engines and for running gas turbines to produce electricity. It was observed that product gas or syngas obtained is around 85–90% pure compared to the gases obtained from coal gasification. Suggestions are made to improve the yield of syngas by suitable designs for specially downdraft gasifiers. Finally, Pyrolysis process of biomass is discussed, and focuses on improving the yield of liquid content by varying the operating conditions. Bio-oil production from pyrolysis can be varied from 65 to 75% by varying operating temperatures (500–650 °C) and heating rate. Finally, in this study we suggest the design of pyrolyser with different operating conditions for maximum yield of liquid, an attempt was made to increase the liquid product and reduce the char/gas content.
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Concerns over climate change coupled with the desire to develop an economy based on renewable and sustainable feedstocks have catalyzed interest in developing pathways and technologies for production of bio-based energy and bio-based products. Biomass utilization plays an important role in this picture since biomass is the only renewable energy source that can offer a direct (e.g., drop-in) replacement for fossil-based transportation fuels in the near to mid term. The United States alone has the capacity to produce more than one billion tons of sustainable biomass, which can be used to produce transportation fuels with dramatically reduced carbon footprints, bio-based chemicals to replace petroleum-derived analogs, and renewable electrical power. A bio-based economy can serve to create new economic opportunities and jobs while simultaneously reducing future climate impacts.
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Sawdust is one of alternative energy sources to substitute the fossil fuels. The utilization of sawdust to produce energy can be done through different types of technologies. Gasification is one of techonology that can be used to convert sawdust into energy. Sawdust has the characteristics of small bulk density and bind to one another. The gasifier type corresponding to these properties is an open top throatless downdraft gasifier. The prediction of producer gas composition can be done through a simulation. This study was conducted to obtain the distribution of combustible gas, tar concentration and temperature at the inside of gasifier on different variations of equivalence ratio by using 2D of computational fluid dynamic. Simulation was performed on the variation of equivalence ratio of 0.2, 0.3 and 0.4. The simulation results showed that the increase of equivalence ratio tend to decrease of CO, H2, CH4 and tar followed by increasing of temperature at the inside of the gasifier.
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Energy derived from biomass provides a promising alternative source that reduces dependence on fossil fuels along with the emission of greenhouse gases (GHG). The production of heat, electricity, power, fuels, and various chemicals from the biomass can be achieved via thermochemical conversion technologies. This chapter summarizes the techno-economic analysis and life-cycle assessment of lignocellulosic biomass via thermochemical conversion routes such as combustion, pyrolysis, gasification, liquefaction, (hydrothermal). and co-firing. Specific indicators such as production costs, techno-economic analysis, functional units, and environmental impacts in a life-cycle analysis for different techniques were compared. Finally, the research lacunae and possible future trends in biomass conversion via thermochemical conversion techniques have been discussed, which may positively impact the future of research related to techno-economic and environmental benefits of bioenergy.
Article
This review covers the characteristics of pyrolysis and catalytic pyrolysis bio‐oils by focusing on the fundamental factors that determine bio‐oil upgradability. The abundant works on the subject of bio‐oil production from lignocellulosic biomass were studied to establish the essential attributes of the bio‐oils for assessment of the oil stability and upgradability. Bio‐oils from catalytic pyrolysis processes relating to catalysts of different compositions and structures are discussed. A general relationship between the higher heating value and the oxygen content in the catalytic pyrolysis oils exists, but this relationship does not apply to the thermal pyrolysis oil. Reporting bio‐oil yield is meaningful only when the oxygen content of the oil is measured because the pyrolytic oil stability is mainly determined by the oxygen content. Isoenergy plot that associates bio‐oil yield with oxygen content is presented and discussed.
Article
Pyrolysis converts biomass into liquid, gaseous and solid fuels. This work reviews the existing models for biomass pyrolysis, including kinetic, network and mechanistic models. The kinetic models are based on the global reaction mechanisms and have been extensively used for a wide range of biomass under various operating conditions. Major emphases have been on the network models as these models predict the structural changes during biomass pyrolysis. Key aspects of various network models include reaction schemes, structural characteristics and applications to CFD simulations. Recent advances in understanding reaction mechanisms using mechanistic models have been summarized. Importance of inherent inorganic species in biomass pyrolysis is also critically analysed. Future studies of biomass pyrolysis modelling should focus on developing multiscale models considering reactions of all biomass components (i.e., cellulose, hemicellulose, lignin, inorganic species and extractives) and potential interactions.
Article
Pyrolysis is considered as a promising method to dispose polymer waste. To provide guidance for pyrolysis recycling of representative non-charring polymer namely poly(methyl methacrylate) (PMMA) waste with micron particle size, the pyrolysis kinetics and reaction mechanism of micron PMMA waste in nitrogen are studied in the present study. Thermogravimetric analyses at 5, 10, 20, 30 and 40 K/min coupled with two model-free methods including Senum-Yang and advanced Vyazovkin method as well as one model-fitting method namely Coats-Redfern method are employed. Results indicate that the micron PMMA waste pyrolysis may be nominally considered as one-step reaction. The reaction model and mechanism in charge of the micron PMMA waste pyrolysis may be g(α)=(1-α)-1/2-1 and chemical reaction, respectively. The average values of the activation energy and pre-exponential factor are 243.69 kJ/mol and 1.19×1019 min-1, respectively, which are both larger than those of traditional PMMA with particle size in millimeter or larger level. Based upon the one-step reaction model and the obtained kinetic parameters, the predicted thermogravimetric data agree well with the experimental results not only at heating rates of 5, 10 and 20 K/min which are employed to calculate the kinetic parameters, but also at heating rates of 30 and 40 K/min beyond those used to calculate the kinetic parameters.
Thesis
The expected growth of the world’s population and the consequent increase in the global energy demand, together with the volatility of the energy market, results in specific uncertainties in the future world economy, which are reflected in the range of oil price projections both in the short and long term. Cuba is an island that lacks sufficient proven fossil energy resources to be able to have an advance in long-term sustainable economic and social development. However, the largest source of domestic energy production comes from imported oil. Hence the importance of the promotion and development of renewable sources of energy. In this sense, sugar cane bagasse (SCB) and trash (SCT) are the main residues derived from the production of sugar from cane which accounted for 3.3% of the total electricity production in the country, albeit the trash not being valorized to a significant extent. Fast pyrolysis is an attractive alternative technology to process sugar cane residues, whereby solid biomass is converted mainly to bio-oil. The bio-oil has the potential for use as a fuel or as a feedstock for the extraction and/or synthesis of more valuable chemical compounds. However, the high heterogeneity and poor fuel quality of crude bio-oil (i.e. high oxygen and water fraction, high acidity, and high viscosity) impose the need for upgrading processes. Nowadays, research efforts have been conducted in pretreatment to address problems associated with the presence of naturally occurring alkali and alkaline earth metals (AAEMs) in biomass. In terms of specific elements, Si, Na, K, Mg and Ca are generally the major inorganic components in sugar cane. These elements have been demonstrated to act as catalysts during fast pyrolysis. Also, they possess large potential to reduce the yield and the bio-oil’s stability, and to alter the resulting bio-oil composition in a negative way. Most notably, AAEMs appear to suppress and/or suppress the pyrolytic production of levoglucosan out of cellulose and favor the production of lighter oxygenates instead. This thesis focuses on the pretreatment of sugar cane residues prior to fast pyrolysis (500 °C) to produce bio-oils to be considered as a fuel or as a chemical platform. First study is centered on the effect of citric acid (CA) pretreatment for removing AAEMs from SCB and SCT and to compare its effectiveness to that of other well-known leaching agents such as demineralized water, HCl and H2SO4. Both raw and pretreated materials structure, thermal behavior and chemical composition are analyzed based on compositional analyses, Fourier transform infrared spectroscopy (FTIR-ATR) and thermogravimetric analysis (TGA). The influence of leaching temperature (T = 25 – 50 °C) and contact time (t = 1 – 12 h) on the removed ash fraction was assessed by using the nonparametric bifactorial analysis of variance proposed by Sokal and Rohlf. It was found that the mass fraction of ash removed (i.e. by leaching with CA and the reference leaching solutions) was in a narrow range (between 38.9 and 54.1%) regardless of biomass type and leaching conditions tested. The nonparametric bifactorial analysis of the results revealed that the nature of the leaching solution and its interaction with contact time are of major significance when demineralizing both SCT and SCB but no significance of temperature and its interaction with contact time was found. The FTIR-ATR revealed a modification of the xylan fraction and the reduction of CO by OH groups, caused by hydrolysis, demonstrating to be important for subsequent thermal degradation. The biomass samples derived from the previous experimental design were then used to evaluate the effect of SCT and SCB leaching by CA (compared with well-known leaching agents including H2SO4, HCl and water) on the chemical composition of the pyrolysis vapors, viz. by applying micro-pyrolysis (Py-GC/MS) at 500 °C. As a result, the yields of levoglucosan in the pyrolysis vapors increased by 5–8 fold when sugar cane biomasses were leached with acids (i.e. CA or well-known inorganic acids). Differences in the range of leaching conditions tested had only minor influence on the composition of the pyrolysis vapors derived from CA pretreated sugar cane residues. CA treatment generally favored the reduction in the total production of ketones and furans independently of temperature and leaching time. Experiments in a bench-scale pyrolysis reactor were conducted to see whether the results obtained in Py-GC/MS can be scaled to an actual fast pyrolysis reactor. The effects of leaching (25 °C and 1 h) sugar cane trash and sugar cane bagasse with CA on the yields and quality of fast pyrolysis bio-oils were studied, a comparison was made with commonly used leaching agents such as water or solutions of HCl and H2SO4. The quality of the obtained bio-oils was assessed by elemental analysis, total acid number (TAN) and water content determinations, combustion calorimetry and gas chromatography-mass spectrometry (GC/MS) analysis. Results from the fast pyrolysis of SCT or SCB pretreated with acids revealed higher yields on raw-feedstock basis (38–45 wt.%) of the organic bio-oil fraction than those from raw and water–leached feedstock, but lower yields of water and char. The most important observations related to bio-oils chemical composition from leaching with CA are a significant increase of the relative abundance of sugars from 15.1% in raw SCT to 44.7% in CA–leached SCT, as well as a decrease in carboxylic acids, ketones, furans and phenols with respect to the raw biomasses. Also, the bio-oils from the pyrolysis of CA–leached SCT and SCB have slightly higher HHVs than those obtained from reference leaching solutions (HCl and H2SO4). The economic viability of pretreatment will depend on the minimization of CA consumption. In this sense, the effect of CA concentration used in pretreatment on the demineralization of SCT and SCB was studied. A comparison was made with H2SO4 as well-known leaching agent. An additional aim was to identify the optimal acid pretreatment concentration and its influence on the chemical characteristics of leached biomass and on the chemical composition of pyrolysis vapors, viz. by applying micro-pyrolysis. In general, the ash removal was found to decrease in both sugar cane residues upon a decrease in the concentration of the leaching solution. Small differences in total mass loss were associated with the type of biomass and the leaching agent used. The HHV of all pretreated samples had negligible differences, although at higher acid concentrations, a small reduction was observed. The proximate and ultimate analysis of leached SCT and SCB showed similar results for all H2SO4 or CA concentrations tested. Py-GC/MS studies at 500 °C of pretreated SCT and SCB showed an increase in the production of levoglucosan with respect to the raw feedstock. However, ketones production decreased by half or more compared to the raw materials irrespective of the acid concentration in pretreatment and the phenols didn’t follow any trend. The nonparametric analysis of results revealed that the pretreatment with lowest concentrations for CA (0.096 kgdm−3) and 0.251 kgdm−3 for H2SO4 have similar influence on the production of levoglucosan than higher concentrations tested. When comparing both biomasses, the nonparametric analysis demonstrated better results in SCB than in SCT with respect to the leaching solution concentration as dependent variable. Raw sugar cane bagasse and trash were pretreated with CA having a concentration of 0.096 kgdm−3. The pretreatments were performed on a 10 dm3 scale and compared to the previous results at 0.25 dm3. The suitability of the pretreatment parameters established for scale up at 10 dm3 were verified by comparing the compositional characteristics of the treated biomasses and its products distribution in the vapor phase (by Py-GC/MS analysis) with previous results at 0.25 dm3 scale. Bio-oil samples were then obtained on a continuous auger pyrolysis reactor. Physicochemical characterization of the bio-oil included GC/MS, elemental composition, higher heating value, water and solids content and pH. Additionally, dynamic viscosity and stability (ageing) of the bio-oils were assessed. The average bio-oil yield on raw-feedstock basis revealed differences below 5% between SCT and SCB for both raw and leached with CA. The most important observations related to the effect of leaching with CA on the bio-oil’s chemical composition are a significant increase of the sugars, as well as a decrease of the carboxylic acids and phenols. From the analysis of the properties of bio-oils from pyrolysis of sugar cane residues, it is concluded that bio-oil samples from both raw or CA–leached SCT and SCB may not be suitable for direct use as a fuel but could be valuable as a chemical platform. The poor quality of bio-oils obtained from the pyrolysis of raw SCT or SCB makes them difficult to be considered as fuel nor for the production of chemical platform molecules. A preliminary economic and environmental analysis associated with the installation and operation of a 2.5 t∙h−1 pyrolysis plant was carried out. The plant was designed for processing sugar cane residues raw (SCT and SCB) or pretreated (L-SCT and L-SCB). The analyses are based on comprehensive mathematical models and experimental data derived from a bench scale pyrolysis reactor using the auger technology. The models were implemented in Aspen One v10.0 and describe the heat, momentum and mass balances involved in both the pretreatment and pyrolysis stages presented as four scenarios. These models allow gathering basic engineering data; and provide the possibility to identify major issues and bottlenecks during the pyrolysis of raw and pretreated feedstock. Additionally, a preliminary cost analysis on the process to foresee its potential application at industrial scale is presented. Finally, an environmental impact study was performed using Life Cycle Assessment (LCA) methodology and extending the system boundaries to agriculture and sugar cane industry stages. The scenarios that use raw biomass are preferred to those that use pretreatment when economic (as well as environmental) aspects are taken into account. Although, the lower quality of bio-oils from raw SCT and SCB allows only using it as a low quality fuel. On the other hand, the investment costs for installing the L-SCT plant are in the same order, with the remarkable difference in the quality of the bio-oil. This last option could attract the attention as a way to valorize the non-edible and usually wasted SCT.
Article
Various phytoremediation residues (PMRs), including Brassica napus L. (BN), Pennisetum sinese (PS) and Lolium perenne L.(LP), were pyrolyzed at 400, 500, 600 and 700 °C, respectively. A series of sequential and single extractions were employed to analyze the chemical speciation and potential environmental risk of Cadmium (Cd) in different phytoremediation residues-derived biochars (PMBs). The results showed that the exchangeable Cd fraction decreased but the residual Cd fraction increased, indicating the inhibition of bioavailability of Cd and low potential ecological risk index of PMBs. When the temperature was over 600 °C, the Cd in biochar was acceptable to the environment and the leaching concentration of Cd extracted by the three extraction methods (distilled water, SPLP and TCLP) were all under the standard limit. Findings from this study illustrated that the treatment of pyrolysis was feasible for the three kinds of PMRs at 600 °C with acceptable environment risk.
Chapter
In the modern world, the aviation sector plays a vital role in human life in terms of public transport and freighting of goods. Depletion of fossil resources and concerns of their effect to global warming is encouraging researchers to search for alternative options. The current work emphasizes the updated thermochemical process technologies over different heterogeneous catalysts with different feedstocks. The main parameters are availability of feedstock, challenges in the use of feedstock and process details. Besides environmental influence, also development status of bio-jet fuels will be presented.
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In order to predict the pyrolysis mechanisms of four different biomasses (Asbos-Psilocaulon utile, Kraalbos-Galenia africane, Scholtzbos-Pteronia pallens, and Palm shell) were investigated by a novel method called Kalman filter and the results compared with the regression analysis. Both analyses were applied to five different generalised biomass pyrolysis models consisting of parallel and series irreversible-reversible reaction steps. The models consisting of reversible reactions in addition to parallel pyrolysis steps demonstrated a better fit with the experimental results. The pyrolysis step from biomass → bio-oil has the highest reaction rates (3.9*10−3, 8.2*10−3, 9.3*10−3, and 13.5*10−3 min−1) compared with the other pyrolysis steps defined in the models. Kalman filter is, therefore, defined as one of the promising filtering and prediction methods for the estimation of detailed pyrolysis mechanisms and model parameters using minimum experimental data.
Chapter
Oil Palm cultivation in Malaysia has provided the world’s largest producer of crude palm oil with more than 7 million tonnes in 1994. Besides producing the crude oil, it also generate the solid waste ie. palm shells, empty fruit bunches and fruit fibres. Part of these waste are used to generate the energy to run the palm oil mill. Surplus amount of hard palm shells are available and could be converted into activated carbon after the conversion to palm char and pyrolysis oil. Preliminary studies were made on the characteristics of palm oil shells in terms of size distribution, physical and chemical properties and the thermal behaviours using TGA. Later an investigation was conducted on the char and liquid derived fuel from oil palm solid waste via fast pyrolysis. For this purpose, fluidised bed pyrolysis were conducted in an inert bed at varying temperature from 400 to 600°C. The liquid product was analysed for its properties and compared with other biomass pyrolysis oils and petroluem fuels. The influence of some process conditions on the relative proportions of the liquid and solid products together with its properties and characteristics are presented. Some data on palm shell char characteristics were also given.
Article
Pyrolysis of poplar bark is investigated in the temperature range of 573–1023 K. The effect of temperature on the gas production rate, gas yield and composition calorific value of gaseous products and carbon conversion is reported. Production of CO, CH4 and CO2 can be predicted by a model based on the assumption that reaction is the rate controlling step.
Article
The devolatilization behaviour of finely-ground (< 0.2 mm) Loy Yang brown coal was investigated under rapid heating conditions using a small-scale fluidized-bed pyrolyser. The pyrolyser operated continuously, coal being fed at rates of 1–3 g/h directly into a bed of sand fluidized by nitrogen. Particle heating rates probably exceeded 104 °C/s. The yields of tar, C1-C3 hydrocarbons and total volatile matter are reported for a pyrolyser-temperature range of 435 to 900 °C. A maximum tar yield of 23% w/w (dry ash-free coal), 60% more than the Fischer assay, was obtained at 580 °C. Yields of C1-C3 hydrocarbons increased with increasing temperature, reaching 8% at 900 °C. Elemental analyses showed that the composition of the tar and char products was strongly dependent on pyrolysis temperature. The effects on the devolatilization behaviour of the coal produced by the moisture associated with the coal, by hydrogen, and by the replacement of the sand by a fluidized bed of petroleum coke were investigated.
Article
Systematic studies of the independent effects of temperature (300-1100°C), solids residence time (0-30 s), and heating rate (less than equivalent to 100-15000°C/s) on the yields, compositions, and rates of formation of products from the rapid pyrolysis of 0.0101 cm thick sheets of cellulose under 5 psig pressure of helium have been performed. The experiments mainly probe the primary decomposition of the cellulose, with contributions from post-pyrolysis reactions being confined to those occuring within and closely proximate to the sample. Temperature and sample residence time are the most important reaction conditions in determining the pyrolysis behavior, while heating rate effects are explicable in terms of their influence on these two parameters. A heavy liquid product of complex molecular composition accounted for 40 to 83 wt % of the volatiles above 400°C. Secondary cracking of this material increased with increasing residence time or temperature and was a significant pathway for producing several light gases. 9 refs.
Article
A process has been investigated for the saccharification of wood, involving prehydrolysis, lignocellulose pyrolysis, and tar hydrolysis. In this process, ground wood was first prehydrolyzed to remove the more readily hydrolyzable hemicelluloses. The residual lignocellulose was then pyrolyzed rapidly to provide a tar containing levoglucosan and its condensation products. The tar was hydrolyzed to convert these products to glucose. Laboratory experiments have shown that this process can convert a common softwood such as Douglas-fir to 14% char and 42% hexoses. This amounts to a 59% recovery of the hexoses: 32% from prehydrolysis and 27% from pyrolysis. The prehydrolysis served not only to remove hemicelluloses, but also to increase the yield of glucose from pyrolysis and subsequent tar hydrolysis. It has been shown that this enhancement is due to the removal of inorganic ash and the catalytic effect of trace amounts of acid remaining in the lignocellulose.
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