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Biomass Steam Gasification with In-Situ CO2 Capture for Enriched Hydrogen Gas Production: A Reaction Kinetics Modelling Approach  [PDF]
Abrar Inayat,Murni M. Ahmad,Suzana Yusup,Mohamed Ibrahim Abdul Mutalib
Energies , 2010, DOI: 10.3390/en3081472
Abstract: Due to energy and environmental issues, hydrogen has become a more attractive clean fuel. Furthermore, there is high interest in producing hydrogen from biomass with a view to sustainability. The thermochemical process for hydrogen production, i.e. gasification, is the focus of this work. This paper discusses the mathematical modeling of hydrogen production process via biomass steam gasification with calcium oxide as sorbent in a gasifier. A modelling framework consisting of kinetics models for char gasification, methanation, Boudouard, methane reforming, water gas shift and carbonation reactions to represent the gasification and CO2 adsorption in the gasifier, is developed and implemented in MATLAB. The scope of the work includes an investigation of the influence of the temperature, steam/biomass ratio and sorbent/biomass ratio on the amount of hydrogen produced, product gas compositions and carbon conversion. The importance of different reactions involved in the process is also discussed. It is observed that hydrogen production and carbon conversion increase with increasing temperature and steam/biomass ratio. The model predicts a maximum hydrogen mole fraction in the product gas of 0.81 occurring at 950 K, steam/biomass ratio of 3.0 and sorbent/biomass ratio of 1.0. In addition, at sorbent/biomass ratio of 1.52, purity of H2 can be increased to 0.98 mole fraction with all CO2 present in the system adsorbed.
Simulation of Oxygen-steam Gasification with CO2 Adsorption for Hydrogen Production from Empty Fruit Bunch  [PDF]
Murni M. Ahmad,Abrar Inayat,Suzana Yusup,Khalik M. Sabil
Journal of Applied Sciences , 2011,
Abstract: Current study focuses on the process development of hydrogen production via gasification of Empty fruit bunch (EFB) with in-situ adsorption of CO2 based on equilibrium modeling approach. The process flowsheet simulation is performed using iCON, PETRONAS process simulation software. This work investigates the influence of the temperature within the range of 600 to 1000C and steam/biomass ratio between 0.1 to 1.0 on the hydrogen yield and product gas composition. The importance of different reactions involved in the system is also discussed. Using the simulation, the optimal operating conditions are predicted to be at 800C and steam/biomass ratio of 0.6. Hydrogen yield of 149g kg-1 of EFB can be obtained at 1000C. The preliminary economic potential per annum of the oxygen-steam gasification system coupled with in situ CO2 adsoprtion is RM 6.64x106 or approximately USD 2x106.
Dairy Biomass-Wyoming Coal Blends Fixed Gasification Using Air-Steam for Partial Oxidation
Gerardo Gordillo,Kalyan Annamalai
Journal of Combustion , 2012, DOI: 10.1155/2012/495894
Abstract: Concentrated animal feeding operations such as dairies produce a large amount of manure, termed as dairy biomass (DB), which could serve as renewable feedstock for thermal gasification. DB is a low-quality fuel compared to fossil fuels, and hence the product gases have lower heat content; however, the quality of gases can be improved by blending with coals. This paper deals with air-steam fixed-bed counterflow gasification of dairy biomass-Wyoming coal blend (DBWC). The effects of equivalence ratio (1.6<Φ<6.4) and steam-to-fuel ratio (0.4<∶<0.8) on peak temperatures, gas composition, gross heating value of the products, and energy recovery are presented. According to experimental results, increasing Φ and (∶) ratios decreases the peak temperature and increases the H2 and CO2 production, while CO production decreases. On the other hand, the concentrations of CH4 and C2H6 were lower compared to those of other gases and almost not affected by Φ.
Catalytic Steam Reforming of Toluene as a Model Compound of Biomass Gasification Tar Using Ni-CeO2/SBA-15 Catalysts  [PDF]
Jun Tao,Leiqiang Zhao,Changqing Dong,Qiang Lu,Xiaoze Du,Erik Dahlquist
Energies , 2013, DOI: 10.3390/en6073284
Abstract: Nickel supported on SBA-15 doped with CeO 2 catalysts (Ni-CeO 2/SBA-15) was prepared, and used for steam reforming of toluene which was selected as a model compound of biomass gasification tar. A fixed-bed lab-scale set was designed and employed to evaluate the catalytic performances of the Ni-CeO 2/SBA-15 catalysts. Experiments were performed to reveal the effects of several factors on the toluene conversion and product gas composition, including the reaction temperature, steam/carbon (S/C) ratio, and CeO 2 loading content. Moreover, the catalysts were subjected to analysis of their carbon contents after the steam reforming experiments, as well as to test the catalytic stability over a long experimental period. The results indicated that the Ni-CeO 2/SBA-15 catalysts exhibited promising capabilities on the toluene conversion, anti-coke deposition and catalytic stability. The toluene conversion reached as high as 98.9% at steam reforming temperature of 850 °C and S/C ratio of 3 using the Ni-CeO 2(3wt%)/SBA-15 catalyst. Negligible coke formation was detected on the used catalyst. The gaseous products mainly consisted of H 2 and CO, together with a little CO 2 and CH 4.
Conversion Synergies during Steam Co-Gasification of Ligno-Cellulosic Simulated Biomass with Coal  [PDF]
Joseph H. Kihedu, Ryo Yoshiie, Yoko Nunome, Yasuaki Ueki, Ichiro Naruse
Journal of Sustainable Bioenergy Systems (JSBS) , 2012, DOI: 10.4236/jsbs.2012.24014
Abstract: Lignin and cellulose chemicals were used as artificial biomass components to make-up a simulated biomass. Alkali and Alkaline Earth Metal (AAEM) as well as volatile matter contents in these chemicals were much different from each other. Co-gasification of coal with simulated biomass shows improved conversion characteristics in comparison to the average calculated from separate conversion of coal and simulated biomass. Two conversion synergetic peaks were observed whereby the first peak occurred around 400℃ while the second one occurred above 800℃. Although co-gasification of coal with lignin that has high AAEM content also shows two synergy peaks, the one at higher temperature is dominant. Co-gasification of coal with cellulose shows only a single synergy peak around 400℃ indicating that synergy at low temperature is related with interaction of volatiles. Investigation of morphology changes during gasification of lignin and coal, suggests that their low reactivity is associated with their solid shape maintained even at high temperature.
Experimental study of high temperature steam gasification of biomass under the catalysis of limonite

- , 2016, DOI: 10.13738/j.issn.1671-8097.2016.01.012
Abstract: 针对生物质气化过程中焦油量大、产气率低等问题,应用高温水蒸气催化气化的方法提高了产氢率,增大了生物质能源的利用率,本高温蒸气气化实验研究以内配褐铁矿粉的松木屑成型颗粒为气化原料,采用廉价易得的褐铁矿作为催化剂,以高温水蒸气作为气化剂。通过实验得出,在配比15%褐铁矿,气化温度750℃、蒸汽流量0.89kg/h条件下,1.5kg成型颗粒1小时总产气量为800L,氢气含量为55.28%,气体热值为11.31MJ/m3,与无添加相比,产气量增加了11.1%,总热能产出增加了5.78%,气化终温850℃下,产气量970L,氢气含量57.13%,热能产出量达到了10.33MJ。
Aiming at the problem of large amount of tar and the low gas production rate, the method of high temperature steam catalytic gasification is used to improved the rate of hydrogen production and utilization of biomass energy. The high temperature steam gasification experimental study was done by using the pine sawdust particles as the gasification raw material which was mixtured of limonite powder and the limonite as catalyst which is cheap and easy to get., high temperature steam as gasification agent. Through the experiment, 1.5kg pine sawdust output gas volume 800L totally in one hour and the highest hydrogen content is 55.28% and gas calorific value is 11.31MJ/m3 under the condition of adding 15% limonite, gasification temperature 750℃ and steam flow 0.89kg/h, compared with the blank experiment,the gas production increased by 11.1% and the total heat output increased by 5.78%, under the gasification temperature of 850℃,gas production is 970L,the hydrogen content is 57.13%,the heat output reached 10.33MJ.
Hua-Jiang Huang,Shri Ramaswamy Mail
BioResources , 2011,
Abstract: Pulp and paper mills represent a major platform for the use of abundant, renewable forest-based biomass as raw material. The pulping processes produce a large amount of black liquor solids, which is currently burnt in a conventional Tomlinson recovery boiler for recovery of energy and inorganic chemicals. This combustion technology can recover chemicals with good efficiency, and steam and power can be produced for the mills. However, Black Liquor Gasification (BLG) can be used to substitute for the combustion process for potential higher energy efficiency, lower greenhouse gas emissions, and more safety. With BLG technology, current pulp and paper mills can be extended into future biorefineries. In this work, a thermodynamic equilibrium model using Gibbs free energy minimization approach and the software FactSage are utilized to analyze the thermodynamic equilibrium constraints of the complex multiple phase reactions and the effects of different operating conditions during black liquor gasification. The modeling results can help better understand the black liquor gasification process and be useful in process modeling and analysis of the future BLG-based biorefinery.
Performance Evaluation and Simulation of Pressurized Gasification
C. Mohanraj,J. Kesavan
International Journal on Theoretical and Applied Research in Mechanical Engineering , 2012,
Abstract: The emergence of biomass based energy warrants the evaluation of syn-gas from biomass gasification as a fuel for power systems. The earlier investigations reveal that the operating parameters strongly affect the syn gas quality. The gasifier performance was investigated with different operating pressure. The downdraft gasifier has tested with silver oak woodchips of size approximately 12mm×12mm×12mm. The total feed of 8-8.5kg of wood was fed into the system and an airflow rate of 130 lpm supplied by compressor and the gasifier was tested different pressure conditions. The main variables namely oxidation zone temperature, combustible gas contents (H2, CO & CH4), calorific value, gas production rate and conversion efficiency was studied. The percentage of total combustible gas is varied between 30.60% - 35.97% and the average composition is N2 = 44.29% – 54.78%, CH4 = 0.62% – 1.51%, H2 = 15.7% – 25.48%, CO = 7.96% – 11.4%, CO2 = 11.37% – 19.70%. The calorific value of syn gas was found to vary between 3.860 MJ/m3 – 4.374.94 MJ/m3. The conversion efficiency varied between 86.8% - 73.7%.Computational fluid dynamics (CFD) method was used to predict the performance of the down draft biomass gasifier. For simulation purpose the combustion zone of the gasifier was separately modeled and analyzed.
Effect of Process Parameters on Hydrogen Production and Efficiency in Biomass Gasification using Modelling Approach  [PDF]
A. Inayat,M.M. Ahmad,M.I. Abdul Mutalib,S. Yusup
Journal of Applied Sciences , 2010,
Abstract: Hydrogen is considered as an attractive clean fuel for the future. Hydrogen production via biomass steam gasification is receiving attention due to its sustainability and zero net carbon emission. Coupled with in situ CO2 adsorption, this process has been proven to be environment friendly. The study reports on the impact of temperature, steam/biomass ratio and sorbent/biomass ratio on hydrogen production performance in a steam gasification process using a simulation model developed in MATLAB. In this study, biomass is assumed as char and gasification and CO2 adsorption occur in one gasifier. The model is used to predict the product gas composition, hydrogen yield and thermodynamic efficiency of the process. The results show that with the increase in temperature and steam/biomass ratio, the hydrogen concentration and yield increase, however, the thermodynamic efficiency decreases. Hydrogen yield increases from 78 to 97 g kg-1 of biomass with the increase in temperature and steam/biomass ratio within the range of 800 to 1300 K and 2.0 to 5.0, respectively. Maximum hydrogen efficiency of 87% is observed at 800 K and steam/biomass ratio of 2.0. At the sorbent/biomass of 1.52, hydrogen purity is predicted to reach 0.98 mole fraction with CO2 present in system absorbed. At 950 K with steam/biomass ratio of 3.0 and sorbent/biomass ratio of 1.0, a maximum hydrogen concentration of 0.81 mole fraction is obtained in the product gas. The steam feed rate is found to have the most impact on the hydrogen production and thermodynamic efficiency among the process parameters.
Thermodynamics analysis of biomass gasification with air-steam

FENG Jie,WU Zhi-bin,QIN Yu-hong,LI Wen-ying,

燃料化学学报 , 2007,
Abstract: 基于Gibbs自由能最小化原理,计算了包括H2O(l)和C(s)在内的,生物质空气-水蒸气气化体系热力学平衡,对比分析了常压气化和加压气化的特点,通过回归分析得到了不同压力下,气化产物中可燃气体分率最高时的水蒸气/生物质质量比(S/B,Steam to Biomass Ratio)与空气当量比(ER,Equivalence Ratio)的关系曲线,为探讨适于制取合成气的气化工艺和条件提供初步的理论指导.研究表明,相对于常压气化,加压气化体系的平衡温度较高,平衡状态下可燃气体分数较低,但CH4含量明显增加;一定温度和当量比下,加压气化使得气化产物中可燃气体分数达到最高所对应的S/B比增大,即需要消耗更多水蒸气;通过调节S/B比,可以比较方便地控制产物中H2和CO的比例.以常压为例,T=1 173 K,S/B=0.17时,气化产物中H2/CO约为1.11,而S/B=1.02时,气化产物中H2/CO约为21;不同压力下最佳S/B比和ER有很好的线性关系,温度为1 173 K时,最佳S/B比与压力及ER的关系为S/B=-1.48×ER-4.49 E×10-5×p2 + 5.83 E×10-3×p + 0.32.
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