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Wei Hsin Chen - One of the best experts on this subject based on the ideXlab platform.
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Torrefaction performance prediction approached by Torrefaction severity factor
Fuel, 2019Co-Authors: Wei Hsin Chen, Ching Lin Cheng, Pau Loke ShowAbstract:Abstract Torrefaction is a crucial biomass upgrading technology to produce biochar for fuel, soil amendment, and bio-absorbent. A number of indicators such as weight loss (WL), Torrefaction severity index (TSI), and severity factor (SF) have been conducted to describe the Torrefaction degree. However, operating conditions such as Torrefaction temperature and duration are not considered in weight loss and Torrefaction severity index, while biomass nature is not taken into account in the severity factor. To overcome these drawbacks, an indicator termed Torrefaction severity factor (TSF) is proposed by introducing a time exponent in the severity factor. Four different biomass materials of Chinese medicine residue, Arthrospira platensis residue, C. sp. JSC4, and spent coffee grounds are examined. After the optimization of the time exponent, TSF can accurately correlate weight loss and thereby Torrefaction severity, and improve the prediction up to 13% when compared to severity factor. In addition, the results suggest that TSF is able to appropriately predict the enhancement factor of HHV and energy yield where the coefficient of determination (R2) is beyond 0.83. Overall, TSF has successfully combined the operating conditions (temperature and duration) and biomass species, can be utilized for predicting Torrefaction performance. This gives a simple and fast way for Torrefaction operation and reactor design, thereby achieving time-saving and efficient predictions.
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Comparison and characterization of property variation of microalgal biomass with non-oxidative and oxidative Torrefaction
Fuel, 2019Co-Authors: Congyu Zhang, Guoliang Cao, Wei Hsin Chen, Chengyu Wang, Shih-hsin HoAbstract:Abstract Oxidative Torrefaction is a noticeable technique for industrial-scale biochar production for fuel, soil amendment, and carbon storage due to its low technological and economic requirement. In this study, two microalgal biomass (Nannochloropsis Oceanica and Chlorella sp.) under the influences of different Torrefaction parameters (i.e., temperature, duration, and carrier gas) are analyzed. To evaluate the variations of the properties of biochar from non-oxidative and oxidative Torrefaction, specific surface area, contact angle, particle size distribution, and scanning electron microscope are measured and characterized. The results indicate that oxidative Torrefaction shortens the Torrefaction duration and possess higher energy efficiency, decarbonization, dehydrogenation, and deoxygenation when compared to non-oxidative Torrefaction. Biochar produced from oxidative Torrefaction has bigger surface area, better hydrophobicity, and palletization behavior, and thus obtained better fuel properties for combustion and industrial application. Nevertheless, the transportation property of biochar produced through oxidative Torrefaction is not as good as that via non-oxidative Torrefaction ones. For the two types of Torrefaction, particle agglomeration, fragmentation, and pore-forming behaviors of the biochar are apparently observed.
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Torrefaction of de oiled jatropha seed kernel biomass for solid fuel production
Energy, 2019Co-Authors: Tau Chuan Ling, Wei Hsin Chen, Cheng Tung ChongAbstract:Non-edible Jatropha seed used for biodiesel production has increased due to its high-oil contents in kernel and potential to reduce greenhouse gas emission. High demand for biodiesel generates a large volume of waste. In this study, de-oiled Jatropha seed kernel was torrefied at 200 °C, 250 °C and 300 °C, holding time of 15, 30, 45 and 60 min and particle sizes of 0.5–1.0 and 1.0–2.0 mm to produce solid fuel. Torrefaction performance was highly affected by Torrefaction temperature compared with holding time. The enhancement factor of HHV increased up to 1.243 after Torrefaction at 300 °C and 60 min with particle size of 0.5–1.0 mm. The large particle size reduces the diffusion rate of Torrefaction vapour through internal pores, thereby producing high solid yield and low enhancement in HHV. The analysis of Torrefaction severity index shows that HHV increase is highly dependent on the weight loss, thereby directly decreasing the total energy in biochar. Scanning electron microscopy image clearly illustrated that the microparticles on the surface were destroyed to increase the porous structure of the biochar with increasing Torrefaction temperature. Severe Torrefaction with particle size of 0.5–1.0 mm was an effective approach to increase the energy content of biochar.
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The Environmental Performance of Torrefied Microalgae Biomass using Torrefaction Severity Factor
2019 IEEE 11th International Conference on Humanoid Nanotechnology Information Technology Communication and Control Environment and Management ( HNICE, 2019Co-Authors: Diana Rose T. Rivera, Alvin B. Culaba, Aristotle T. Ubando, Wei Hsin ChenAbstract:Torrefaction is a thermochemical process for upgrading raw biomass into a more energy-dense fuel. However, the production of torrefied microalgae biochar may include environmental impact as it consumes raw materials and energy. In this study, a life cycle assessment study was conducted to understand and assess the corresponding global warming potential associated with the production of torrefied microalgae biomass, using a cradle-to-gate scope. Using different scale models of torrefied microalgae biomass production, this study identifies the contribution of the Torrefaction process to the overall environmental impact. Using the experimental data, the study was able to analyze the impact of the Torrefaction process on biomass thermal degradation using the Torrefaction severity factor. The inclusion of the Torrefaction severity factor shows that there was a strong relationship on the resulted global warming potential. It revealed that the influence of the Torrefaction temperature was higher as compared to the Torrefaction duration.Result of the study shows that the Torrefaction process had a minimal contribution of 1-20% to the resulted overall environmental impacts. The overall impact shows that up-scaling production can result in a negative carbon dioxide emission.
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A study of hygroscopic property of biomass pretreated by Torrefaction
2018Co-Authors: Wei Hsin Chen, Baptiste Colin, Anélie Petrissans, Mathieu PetrissansAbstract:Torrefaction is a thermochemical conversion process, and it is adopted to improve the drawbacks of raw biomass (such as high hygroscopicity, low calorific values and energy density). During this process, biomass is thermally degraded in an inert or nitrogen environment at temperature range of 200-300 degrees C for several minutes to several hours. In this study, high homogeneous torrefied wood samples were produced by Torrefaction at 200, 210, 220, and 230 degrees C. The equilibrium moisture content (EMC) of raw and torrefied wood and the contact angle of sample surface are examined to evaluate the hygroscopicity changes of torrefied wood. The results indicate that the EMC of the torrefied wood decreased by 35% or more compared to the EMC of raw material. An increasing of contact angle of torrefied wood surface is observed with increasing Torrefaction temperature, and it is in the range of 103-113 degrees which is correspond to hydrophobic surface (>900). Meanwhile, the detailed mechanisms about the changes of biomass hygroscopicity after torrefacion are also illustrated in the present work.
Quang-vu Bach - One of the best experts on this subject based on the ideXlab platform.
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Isothermal Torrefaction kinetics for sewage sludge pretreatment
Fuel, 2020Co-Authors: Quyen Le Nguyen, Dinh Duc Nguyen, Hai Vothi, Chao He, Marjan Goodarzi, Quang-vu BachAbstract:Abstract Torrefaction of sewage sludge, a by-product from waste water treatment plants, has been receiving increased attentions in terms of sustainable sludge treatment, energy recovery and possibility to mitigate the environmental impacts. Torrefied sewage sludge is recognized as a better solid fuel than the dry sewage sludge, and it is also beneficial for subsequent thermochemical processes. In this study, sewage sludge was subjected to different Torrefaction conditions in a thermogravimetric analyzer. The thermogravimetric data were then simulated using a two-consecutive reaction model to reproduce the mass losses during Torrefaction. The obtained results from the Torrefaction of the non-lignocellulosic biomass are also compared with other lignocellulosic biomass including a softwood and a hardwood. The findings from this study reveal that the non-lignocellulosic biomass is less thermally resistant and degrades much faster than the lignocellulosic biomass during the first stage of Torrefaction. Moreover, the solid yield from the sewage sludge Torrefaction at temperatures less than 280 °C is lower than that from the woody biomass Torrefaction. However, this trend is inverted when the Torrefaction temperature attains 280 °C and higher. The results obtained are useful for new design or retrofit of the sewage sludge Torrefaction processes.
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Process modeling for Torrefaction of birch branches
Energy Procedia, 2017Co-Authors: Quang-vu Bach, Øyvind SkreibergAbstract:Abstract This work presents a complete biomass Torrefaction model for Norwegian birch branches. The model can provide detailed distribution of both the main and by-products from the Torrefaction process. Reduction in mass and energy yields as well as increase in heating value of the torrefied biomass with increasing Torrefaction temperature are observed. Simulation results show good agreement with available experimental data in the literature. Furthermore, the overall energy consumption and the process energy efficiency can be also estimated, which is essential for process up-scaling. It reveals that drying accounts for 76-81% of the total heat demand. More importantly, the process energy efficiency reduces with increasing temperature thus Torrefaction at high temperatures is not advisable. The information obtained from the model is important for industrialization and commercialization of the Torrefaction process.
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effects of wet Torrefaction on pyrolysis of woody biomass fuels
Energy, 2015Co-Authors: Quang-vu Bach, Khanh-quang Tran, Øyvind Skreiberg, Thuat T TrinhAbstract:The pyrolysis of Norway spruce and birch woods under nitrogen atmosphere was studied by means of a thermogravimetric analyzer operated in the non-isothermal mode, followed by a kinetic analysis employing a three-pseudo-component model with nth-order reactions. Raw woods and the woods treated via wet Torrefaction in the conditions of various temperatures (175, 200, 225 °C) and holding times (10, 30, 60 min) were included in this work. The study showed that wet Torrefaction resulted in higher pyrolysis peaks for the woods, but less mass of volatiles was released during pyrolysis. The effects of wet Torrefaction on pyrolysis of the lignocellulosic components are different. The activation energy of hemicellulose was significantly reduced by wet Torrefaction. However, those for cellulose and lignin were slightly increased by wet Torrefaction.
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Dry and Wet Torrefaction of Woody Biomass-A Comparative Studyon Combustion Kinetics
Energy Procedia, 2015Co-Authors: Quang-vu Bach, Khanh-quang TranAbstract:The combustion kinetics of Norway spruce woody treated via wet or dry Torrefaction were studied and compared. Dry and wet Torrefaction of woodwere performed in compatible conditions on the basis of a common massyield. The combustion experiments were studiedthermogravimetrically, followed by a kinetic evaluation assuming a four-pseudo-component model. The results show that dry-torrefied wood is less reactive in the devolatilization step but more reactive in the char combustion, compared to wet-torrefied one. Dry Torrefaction removesmore hemicellulose from Norway spruce wood than wet Torrefaction, in compatible conditions. The activation energy and pre-exponential factor of cellulose and lignin in the devolatilization step are increased by both Torrefaction methods. However, in the char combustion the activation energy and pre-exponential factor areincreased by dry Torrefaction, but decreased after wet Torrefaction.
Haibin Li - One of the best experts on this subject based on the ideXlab platform.
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uncovering structure reactivity relationships in pyrolysis and gasification of biomass with varying severity of Torrefaction
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Anqing Zheng, Zengli Zhao, Luwei Li, Yuqian Huang, Dongyan Zhang, Haibin LiAbstract:The objective of this study is to establish the structure–reactivity relationships in pyrolysis and gasification of biomass with varying severity of Torrefaction. Pine was torrefied in a bench scale tubular reactor with varying Torrefaction temperature (220–300 °C). The structural alterations in torrefied pine and its derived biochar were characterized by solid-state nuclear magnetic resonance spectroscopy (NMR) and Raman spectroscopy, respectively. The effect of Torrefaction severity, as well as the resulting structural changes in pine, upon subsequent pyrolysis and gasification reactivity were systematically studied. The experimental results showed that the pyrolysis reactivity of pine was promoted by Torrefaction, whereas the gasification reactivity of biochar derived from pine was reduced by Torrefaction. The results were mainly attributed to the severe degradation, polycondensation, and carbonization of hemicellulose and lignin fractions during Torrefaction of pine. The pyrolysis and gasification rea...
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comparison of the effect of wet and dry Torrefaction on chemical structure and pyrolysis behavior of corncobs
Bioresource Technology, 2015Co-Authors: Anqing Zheng, Zengli Zhao, Sheng Chang, Zhen Huang, Kun Zhao, Fang He, Haibin LiAbstract:Wet and dry Torrefaction of corncobs was conducted in high-pressure reactor and tube-type reactor, respectively. Effect of wet and dry Torrefaction on chemical structure and pyrolysis behavior of corncobs was compared. The results showed that hemicellulose could be effectively removed from corncobs by Torrefaction. However, dry Torrefaction caused severe degradation of cellulose and the cross-linking and charring of corncobs. X-ray diffraction analysis revealed that crystallinity degree of corncobs was evidently enhanced during wet Torrefaction, but reduced during dry Torrefaction as raising treatment temperature. In thermogravimetric analysis, wet torrefied corncobs produced less carbonaceous residues than raw corncobs, while dry torrefied corncobs gave much more residues owing to increased content of acid insoluble lignin. Pyrolysis–gas chromatography/mass spectroscopy analysis indicated that wet Torrefaction significantly promoted levoglucosan yield owing to the removal of alkali metals. Therefore, wet Torrefaction can be considered as a more effective pretreatment method for fast pyrolysis of biomass.
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Catalytic Fast Pyrolysis of Biomass Pretreated by Torrefaction with Varying Severity
Energy & Fuels, 2014Co-Authors: Anqing Zheng, Zengli Zhao, Zhen Huang, Kun Zhao, Fang He, Xiaobo Wang, Haibin LiAbstract:Pretreatment of corncobs using Torrefaction was performed in a tubular reactor with varying reaction temperature (210, 240, 270, or 300 °C) and residence time (20, 40, or 60 min). The torrefied corncobs were subsequently catalytically fast pyrolyzed over nanosized HZSM-5 in a semibatch pyroprobe reactor. The torrefied corncobs were characterized by elemental analysis, thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (FTIR), and FTIR. The aromatic production was online analyzed by gas chromatography mass spectroscopy. The effect of Torrefaction severity on product distribution and aromatic selectivity from catalytic fast pyrolysis of torrefied corncobs was investigated. The experimental results show that Torrefaction can serve as an effective thermal pretreatment for improving the selectivity of BTX (benzene, toluene, and xylenes). Light and mild Torrefaction (Torrefaction at 210 and 240 °C) has little impact on the aromatic yield. However, severe Torrefaction (Torrefaction a...
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effect of Torrefaction on structure and fast pyrolysis behavior of corncobs
Bioresource Technology, 2013Co-Authors: Anqing Zheng, Zengli Zhao, Sheng Chang, Zhen Huang, Fang He, Xiaobo Wang, Haibin LiAbstract:Pretreatment of corncobs using Torrefaction was conducted in an auger reactor at 250-300 degrees C and residence times of 10-60 min. The torrefied corncobs were fast pyrolyzed in a bubbling fluidized bed reactor at 470 degrees C to obtain high-quality bio-oil. The heating value and pH of the bio-oil improved when the Torrefaction as pretreatment was applied; however, increasing bio-oil yield penalties were observed with increasing Torrefaction severity. Fourier transform infrared Spectroscopy (FTIR) and quantitative solid C-13 nuclear magnetic resonance spectrometry (NMR) analysis of torrefied corncobs showed that the devolatilization, crosslinking and charring of corncobs during Torrefaction could be responsible for the bio-oil yield penalties. Gas chromatography-mass spectrometry (GC-MS) analysis showed that the acetic acid and furfural contents of the bio-oil decreased with Torrefaction temperature or residence time. The results showed that Torrefaction is an effective method of pretreatment for improving bio-oil quality if the crosslinking and charring of biomass can be restricted. (C) 2012 Elsevier Ltd. All rights reserved.
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effect of Torrefaction temperature on product distribution from two staged pyrolysis of biomass
Energy & Fuels, 2012Co-Authors: Anqing Zheng, Zengli Zhao, Sheng Chang, Zhen Huang, Fang He, Haibin LiAbstract:Two-staged biomass pyrolysis process consisting of Torrefaction and subsequent fast pyrolysis is proposed to obtain high quality bio-oil. The purpose of this study is to evaluate the effect of Torrefaction temperature on yield, composition, and physical properties of the liquid of Torrefaction and bio-oil. Torrefaction of pine was conducted on an auger reactor at 240–320 °C with a residence time of 40 min to produce liquid of Torrefaction and torrefied pine. Then, the torrefied pine was fast pyrolyzed in a bubbling fluidized bed reactor at 520 °C to produce bio-oil. Torrefied pine was characterized by chemical composition analysis and Fourier transform infrared (FTIR) spectroscopy. The liquid of Torrefaction was determined by gas chromatography (GC); bio-oil was characterized by gas chromatography mass spectroscopy (GC-MS) and 13C nuclear magnetic resonance spectrometry (NMR). The experimental results show that water content in liquid of Torrefaction and water and acetic acid content in bio-oil decreased ...
Richard D. Boardman - One of the best experts on this subject based on the ideXlab platform.
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A review on biomass Torrefaction process and product properties for energy applications
Industrial Biotechnology, 2011Co-Authors: Jaya Shankar Tumuluru, J Richard Hess, Christopher T Wright, Shahab Sokhansanj, Richard D. BoardmanAbstract:Torrefaction of biomass can be described as a mild form of pyrolysis at temperatures typically ranging between 200 and 300°C in an inert and reduced environment. Common biomass reactions during Torrefaction include devolatilization, depolymerization, and carbonization of hemicellulose, lignin, and cellulose. The Torrefaction process produces a brown to black uniform solid product, as well as condensable (water, organics, and lipids) and noncondensable gases (CO2 , CO, and CH4 ). Typically during Torrefaction, 70% of the mass is retained as a solid product, containing 90% of the initial energy content, while 30% of the lost mass is converted into condensable and noncondensable products. The system’s energy efficiency can be improved by reintroducing the material lost during Torrefaction as a source of heat. Torrefaction of biomass improves its physical properties like grindability; par- ticle shape, size, and distribution; pelletability; and proximate and ultimate composition like moisture, carbon and hydrogen content, and calorific value. Compared to raw biomass, the carbon content and calorific value of torrefied biomass increases by 15–25% wt, while the moisture content decreases to
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REVIEW: A review on biomass Torrefaction process and product properties for energy applications
Industrial Biotechnology, 2011Co-Authors: Jaya Shankar Tumuluru, Christopher T Wright, J Richard Hess, Shahab Sokhansanj, Richard D. BoardmanAbstract:Torrefaction of biomass can be described as a mild form of pyrolysis at temperatures typically ranging between 200 and 300°C in an inert and reduced environment. Common biomass reactions during Torrefaction include devolatilization, depolymerization, and carbonization of hemicellulose, lignin, and cellulose. The Torrefaction process produces a brown to black uniform solid product, as well as condensable (water, organics, and lipids) and Noncondensable gases (CO 2, CO, and CH 4). Typically during Torrefaction, 70% of the mass is retained as a solid product, containing 90% of the initial energy content, while 30% of the lost mass is converted into condensable and noncondensable products. The system's energy efficiency can be improved by reintroducing the material lost during Torrefaction as a source of heat. Torrefaction of biomass improves its physical properties like grindability; particle shape, size, and distribution; pelletability; and proximate and ultimate composition like moisture, carbon and hydrogen content, and calorific value. Compared to raw biomass, the carbon content and calorific value of torrefied biomass increases by 15-25% wt, while the moisture content decreases to
Shahab Sokhansanj - One of the best experts on this subject based on the ideXlab platform.
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a study of particle size effect on biomass Torrefaction and densification
Energy & Fuels, 2012Co-Authors: Jianghong Peng, H T Bi, Shahab SokhansanjAbstract:The particle size effect on Torrefaction of pine particles and formation of torrefied pellets has been studied in a thermogravimetric analyzer (TGA) and a tubular fixed bed reactor. The fixed bed reactor was also used to produce torrefied samples for a single-die press unit for the densification test. Both the TGA and fixed bed reactor Torrefaction test results showed that the Torrefaction rate was affected by the particle size, especially at high temperatures. Although the temperature gradient inside particles smaller than 1 mm is very small during Torrefaction, the internal diffusion of generated vapors inside particles imposes an impact on the global Torrefaction reaction rate. The hard core or nonshrinkage particle model with a first order Torrefaction reaction can predict the reaction data reasonably well, with the data-fitted effective vapor diffusivity coefficient. The densification tests showed that more energy was required to make pellets from larger torrefied particles, while the water uptake an...
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Development of Torrefaction Kinetics for British Columbia Softwoods
International Journal of Chemical Reactor Engineering, 2012Co-Authors: Jianghong Peng, Xiaotao Bi, Shahab SokhansanjAbstract:Torrefaction is a thermal treatment without air or oxygen in the temperature range of 473-573 K. The pyrolysis kinetics of three chemical components (cellulose, hemicelluloses, and lignin) and wood at low temperatures of relevance to Torrefaction conditions have been reviewed. A series of thermogravimetric (TG) experiments have been carried out to study the intrinsic Torrefaction kinetics of major chemical components and British Columbia (BC) softwoods. The weight loss during BC softwood Torrefaction was found to be mainly associated with the decomposition of hemicelluloses, although there was also certain degree of decomposition of cellulose and lignin. The weight loss of the BC softwoods during Torrefaction could be approximately estimated from the chemical composition of wood species and the weight loss data for Torrefaction of pure cellulose, hemicelluloses, and lignin, respectively. Based on the fitting of the TG curves of BC softwoods and three chemical components, two different torrefaciton models were proposed. The simple one-step (single-stage) kinetic model with the first order reaction can predict the reaction data reasonably well over the long residence time, with the final sample weight being strongly related to the Torrefaction temperature. A two-component and one-step first order reaction kinetic model, on the other hand, gave improved agreement with data over short residence time, and can be used to guide the design and optimization of Torrefaction reactors over the weight loss range of 0 to 40% at the temperature range of 533-573 K, which covers the typical range of industrially relevant operations.
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A review on biomass Torrefaction process and product properties for energy applications
Industrial Biotechnology, 2011Co-Authors: Jaya Shankar Tumuluru, J Richard Hess, Christopher T Wright, Shahab Sokhansanj, Richard D. BoardmanAbstract:Torrefaction of biomass can be described as a mild form of pyrolysis at temperatures typically ranging between 200 and 300°C in an inert and reduced environment. Common biomass reactions during Torrefaction include devolatilization, depolymerization, and carbonization of hemicellulose, lignin, and cellulose. The Torrefaction process produces a brown to black uniform solid product, as well as condensable (water, organics, and lipids) and noncondensable gases (CO2 , CO, and CH4 ). Typically during Torrefaction, 70% of the mass is retained as a solid product, containing 90% of the initial energy content, while 30% of the lost mass is converted into condensable and noncondensable products. The system’s energy efficiency can be improved by reintroducing the material lost during Torrefaction as a source of heat. Torrefaction of biomass improves its physical properties like grindability; par- ticle shape, size, and distribution; pelletability; and proximate and ultimate composition like moisture, carbon and hydrogen content, and calorific value. Compared to raw biomass, the carbon content and calorific value of torrefied biomass increases by 15–25% wt, while the moisture content decreases to
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REVIEW: A review on biomass Torrefaction process and product properties for energy applications
Industrial Biotechnology, 2011Co-Authors: Jaya Shankar Tumuluru, Christopher T Wright, J Richard Hess, Shahab Sokhansanj, Richard D. BoardmanAbstract:Torrefaction of biomass can be described as a mild form of pyrolysis at temperatures typically ranging between 200 and 300°C in an inert and reduced environment. Common biomass reactions during Torrefaction include devolatilization, depolymerization, and carbonization of hemicellulose, lignin, and cellulose. The Torrefaction process produces a brown to black uniform solid product, as well as condensable (water, organics, and lipids) and Noncondensable gases (CO 2, CO, and CH 4). Typically during Torrefaction, 70% of the mass is retained as a solid product, containing 90% of the initial energy content, while 30% of the lost mass is converted into condensable and noncondensable products. The system's energy efficiency can be improved by reintroducing the material lost during Torrefaction as a source of heat. Torrefaction of biomass improves its physical properties like grindability; particle shape, size, and distribution; pelletability; and proximate and ultimate composition like moisture, carbon and hydrogen content, and calorific value. Compared to raw biomass, the carbon content and calorific value of torrefied biomass increases by 15-25% wt, while the moisture content decreases to
