杏仁壳流化床气化实验研究

在流化床生物质气化炉内,采用空气作为气化剂,对杏仁壳进行了气化实验研究。实验表明：产生的燃气热值在4741～5418kJ／Nm^3之间,主要燃气成分含量为CO：15．4％～18．7％,H2：9．9％～14．7％,CH4：2％～2．5％,气化炉最佳气化温度为700℃,产气率为0．41m^3／Kg。     

3000kW生物质锥形流化床气化发电系统工程设计及应用

本文主要论述了自主研发的3000kW生物质锥形流化床气化发电机组工程，对气化发电系统的工艺过程、设备设计要点及系统运行情况分别进行了阐述。研究设计的气化发电系统工程运行结果表明锥形流化床气化炉操作弹性大，分布锥结构很好地改善了气体分布状况，最佳气化温度为710—740℃。系统运行数据表明：生物质耗量为1．77kg／kWh，每公斤稻壳产气为1．62Nm^2，系统总效率为15％，发电机转化效率25％。     

生物质下吸式气化炉气化制备富氢燃气实验研究

以制取富氢燃气为目标,在自热式下吸式气化炉反应器内,进行了生物质下吸式气化炉富氧/水蒸气及空气气化的制氢特性研究。实验结果表明,与空气气化相比,富氧/水蒸气气化可显著提高氢产率和产气热值。在实验条件范围内,最大氢产率达到45.16 g/kg;最大低位热值达到11.11 MJ/m3。在富氧/水蒸气气化条件下,燃气中H2+CO体积分数达到63.27%—72.56%,高于空气气化条件下的52.19%—63.31%。富氧/水蒸气气化条件下的H2/CO体积比比值为0.70—0.90,低于空气气化条件下的1.06—1.27。实验结果证实:生物质下吸式气化炉富氧/水蒸气气化是一种有效的制取可再生氢源的工艺路线。     

生物质流化床气化炉气化过程的实验研究

在流化床生物质气化炉内 ,采用空气作气化剂 ,对七种农、林废弃物进行了气化实验研究。生成的燃气成分 :CO在 1 4 %～ 1 7%之间 ,H2 含量一般低于 1 0 % ,甲烷含量为 5%～ 1 0 %。燃气热值多数在 53 0 0～ 6 50 0 k J/ Nm3 ,气化效率 72 .6 %。实验结果表明 ,流化床生物质气化炉可用于生物质气化。     

CO2＋O2气化制气配水煤气生产甲醇的构想与可行性分析

以干燥后的焦炭为原料，O2和CO2为气化剂，在气化炉内进行气化反应并制得粗CO气。主要反应如下：C＋O2=CO2＋394．4kJ／mol（1）、C＋CO2=2CO—168．5kJ／mol（2）、C＋1／2O2=CO＋112．9kJ／mol（3）。反应主要按（1）、（2）式进行，反应（1）、（3）为氧化反应，是强放热过程，反应（2）为还原反应，是吸热过程。CO2除参与反应外，还起调节温度作用，控制燃烧层最高温度低于灰熔点（t2），防止灰渣结块。     

流化床作为生物质气化反应器试验研究

在流化床生物质气化炉内 ,用空气进行气化生物质 (花生壳 )的试验研究 ,分析的参数是当量比ER 0 .2— 0 .4 5 ,气化床的温度 75 0— 85 0℃和加入二次风。当ER在 0 .2 5— 0 .33,气化燃气热值为 6 .2— 6 .8MJ/m3 ,气体产量在 2 6 0— 390m3 /h ,生物质燃烧时比气化产量在 1.2 8— 2 .0 3m3 /kg之间 ,炭转化率在 5 3%— 80 %。并对 7种农、林废弃物进行了初步气化试验研究 ,生成的燃气体积分数 :CO为 14 %— 18% ,H2 一般低于 6 % ,甲烷 4 %— 12 %。燃气热值在 4 70 0— 710 0kJ/m3 。试验结果表明 ,在流化床生物质气化炉中 ,通过在悬浮空间加入二次风 ,可使燃气热值得到提高。     

3000kW生物质锥形流化床气化发电系统 工程设计及应用

本文主要论述了自主研发的3000 kW生物质锥形流化床气化发电机组工程,对气化发电系统的工艺过程、设备设计要点及系统运行情况分别进行了阐述。研究设计的气化发电系统工程运行结果表明锥形流化床气化炉操作弹性大,分布锥结构很好地改善了气体分布状况,最佳气化温度为710～740℃。系统运行数据表明:生物质耗量为1.77 kg/kWh,每公斤稻壳产气为1.62 Nm³,系统总效率为15%,发电机转化效率25%。     

不同配气工艺下生物质固定床气化试验研究

采用自主研发的连续运行主动配气下吸式固定床气化炉为试验平台,研究了不同配气工艺下气化炉内温度场和压力场的变化,并且以稻草为气化原料进行气化试验,分析了不同配气工艺对燃气组分、燃气热值和燃气中焦油质量浓度的影响。结果表明:改变配气工艺从单层配气到双层配气再到三层配气,反应炉内温度逐渐升高,反应炉内各层压力逐渐均匀,三层配气时炉内氧化层温度在1 100℃左右,炉内最高压力为24.1 kPa,三层配气时气化炉内温度场和压力场的分布具有较高气化反应特性;同单层配气和双层配气相比,三层配气工艺下以稻草为气化原料燃气组分中H2和CO的体积分数明显提高,其值分别为10.23%和20.49%,相比于单层配气提高了3.08%和2.28%,单层配气、双层配气和三层配气工艺下燃气热值分别为4 656.82 kJ/m3、4 934.99 kJ/m3和5 476.77 kJ/m3,燃气中焦油质量浓度分别为0.834×10-3kg/m3、0806×10-3kg/m3和0.721×10-3kg/m3。     

气流床粉煤气化性能模拟分析

基于Aspen Plus工作平台,运用Gibbs自由能最小化原理,对气流床粉煤气化过程进行了数值模拟,并对流程算法进行了改进。研究了氧煤比、蒸气煤比、压力及粉煤粒径对气化炉出口气体组成、温度、冷煤气效率、碳转化率及有效气产率的影响。结果表明：模拟值和实验值有良好的相似性;氧煤比对气化进程的影响较蒸汽煤比及其它操作条件更为显著;并确定了模拟煤种的最佳氧煤比是0．70～0．80kg／kg,气化炉出口CO＋H2的最大干基体积分数为96．48％,冷煤气效率最高为83．56％,最大有效气产率为1．74m^3／kg;氧煤比每升高0．1kg／kg,气化炉出口温度升高约40℃,而蒸汽煤比每升高0．1kg／kg,气化炉出口温度降低约8℃。     

玉米秸秆循环流化床气化中试试验

玉米秸秆是农业生产过程中产生的剩余物,其热解气化是秸秆类生物质处理应用的重要选择方向。为此,采用循环流化床气化中试装置对玉米秸秆进行了气化试验,研究空气当量比ER、原料含水率对反应温度、气化燃气组分与热值、气化效率及燃气中的焦油含量等气化特性影响规律,并通过改变进料量试验得到了在不同负荷运行条件下的优化工作参数。结果表明：①随着ER的增大,循环流化床气化炉内的反应温度升高,气化燃气中的CO₂含量增加,焦油与CO含量及燃气热值降低,气化效率随ER的增大呈现先增大后减小趋势,较理想的ER为0.26,此时的气化效率达到70.2%、燃气热值为5.1MJ/m³;②原料含水率的增大降低了气化炉内的反应温度,当原料含水率在5%～15%之间逐渐增大时,燃气中的H₂含量、燃气热值及气化效率均有提升,当含水率由15%继续增大到25%过程中,燃气热值与气化效率均出现了快速下降;③根据气化炉额定进料量设计值,改变进料负荷在66%～120%范围内,调节ER在0.26～0.3时均可得到较好的运行工况,对应得到的燃气热值为4.8～5.1MJ/m³、气化效率为69%～72%。     

生物质两段式富氧气化-燃气轮机燃烧集成发电系统模拟研究

为实现生物质能量的高效清洁利用,本研究基于两段式富氧气化系统改进燃气品质,并将获得的洁净高热值可燃气用于燃气轮机燃烧.通过Aspen Plus模拟研究分析了氧体积分数、气化温度对气化特性、燃机运行特性的影响,研究结果证实了生物质气化燃气在燃气轮机应用的可行性,并发现氧体积分数提高对改善生物质气化燃气品质及系统发电效率具...     

高铝矾土改性对稻草热解与气化特性的影响

在固定床中研究了高铝矾土改性剂及其浓度和反应温度对稻草热解产气特性的影响,选取固定床中最佳实验条件,在流化床中研究了改性高铝矾土床料对稻草气化特性及焦油产率的影响。结果表明,不同物质改性的高铝矾土对稻草热解产气特性的影响不同,4种物质提高稻草热解产气能力的顺序为CaCl2相似文献   

The feasibility of a coal gasifier combined with a high-temperature fuel cell

The purpose of the study presented in this paper was to find out the feasibility of integrating a 50 MW fuel cell system, fed by gas from a coal gasifier, with an existing network for distribution of heat and power. The work presented is the results of the technical evaluation of a 50 MW coal fired high-temperature fuel cell power plant. The overall system can be divided into four subsystems including: coal gasification, gas cleaning, power generation and heat recovery.

The final system, a entrained flow gasifier combined with standard low-temperature gas cleanup and SOFC, resulted in an overall electrical efficiency of about 47%, and an overall efficiency close to 85%.     

Performance analysis of integrated biomass gasification fuel cell (BGFC) and biomass gasification combined cycle (BGCC) systems

Biomass gasification processes are more commonly integrated to gas turbine based combined heat and power (CHP) generation systems. However, efficiency can be greatly enhanced by the use of more advanced power generation technology such as solid oxide fuel cells (SOFC). The key objective of this work is to develop systematic site-wide process integration strategies, based on detailed process simulation in Aspen Plus, in view to improve heat recovery including waste heat, energy efficiency and cleaner operation, of biomass gasification fuel cell (BGFC) systems. The BGFC system considers integration of the exhaust gas as a source of steam and unreacted fuel from the SOFC to the steam gasifier, utilising biomass volatilised gases and tars, which is separately carried out from the combustion of the remaining char of the biomass in the presence of depleted air from the SOFC. The high grade process heat is utilised into direct heating of the process streams, e.g. heating of the syngas feed to the SOFC after cooling, condensation and ultra-cleaning with the Rectisol^® process, using the hot product gas from the steam gasifier and heating of air to the SOFC using exhaust gas from the char combustor. The medium to low grade process heat is extracted into excess steam and hot water generation from the BGFC site. This study presents a comprehensive comparison of energetic and emission performances between BGFC and biomass gasification combined cycle (BGCC) systems, based on a 4th generation biomass waste resource, straws. The former integrated system provides as much as twice the power, than the latter. Furthermore, the performance of the integrated BGFC system is thoroughly analysed for a range of power generations, ～100–997 kW. Increasing power generation from a BGFC system decreases its power generation efficiency (69–63%), while increasing CHP generation efficiency (80–85%).     

Tar removal from the producer gas of a small scale downdraft gasifier using a fatty acid based,wet packed-bed scrubber

Small scale gasification combined heat and power (CHP) systems offer an alternative to diesel fuelled generators for power generation in remote communities and industrial sites. Tar and particulates in the producer-gas can damage the internal combustion engine generator and increase operation and maintenance costs. In this work, we present a novel trickle-bed scrubber using filtered waste cooking oil as a cost effective and easy-to-operate gas clean-up method for a small CHP system. The performance of the trickle-bed scrubber was compared against a packed-bed filter utilizing woodchips in a 20 kW_th downdraft gasifier. Used-cooking oil was selected as the solvent and woodchips as the bed-material as these are readily available, inexpensive, and can be recycled in the gasifier as fuel. A woodchip packed-bed filter reduced the tar and particulate matter (PM) in the producer gas from gasification of spruce chips (11% moisture) from 1.6 to 1.4 g/Nm³ and from 0.16 to 0.087 g/Nm³ respectively. The trickle-bed scrubber was able to reduce the tar and PM in the producer gas from gasification of pinewood (8% moisture) from 1.38 to 0.28 g/Nm³, and 0.209 to 0.082 g/Nm³, respectively. Tar and PM removal efficiency improved by 60% and 29% respectively. Components such as benzene, toluene, naphthalene, and biphenylene were the major tar components. After passing the trickle-bed, most tar was removed, with a preference for removal of multi-ringed aromatics and gravimetric tars. Parameters such as the tar and particulate concentration, feedstock moisture content, and feedstock source affect the performance of the gas clean-up system.     

High-efficiency and pollution-controlling in-situ gasification chemical looping combustion system by using CO2 instead of steam as gasification agent

Using CO₂ as gasification agent instead of steam in in-situ coal gasification chemical looping combustion (iG-CLC) power plant can eliminate energy consumption for steam generation, thus obtaining higher system efficiency. In this work, a comparative study of iG-CLC power plant using steam and CO₂ as gasification agent is concentrated on. The effects of steam to carbon ratio (S/C) and CO₂ to carbon ratio (CO₂/C) on the fuel reactor temperature, char conversion, syngas composition and CO₂ capture efficiency are separately investigated. An equilibrium carbon conversion of 88.9% is achieved in steam-based case as S/C ratio increases from 0.7 to 1.1, whereas a maximum conversion of 84.2% is obtained in CO₂-based case with CO₂/C ranging from 0.7 to 1.1. Furthermore the effects of oxygen carrier to fuel ratio (φ) on system performances are investigated. Increasing φ from 1.0 to 1.4 helps to achieve char conversion from 75.9% to 88.9% in steam-based case, by contrast the char conversion can achieve 66.3%-84.2% in CO₂-based case within the same φ range. In terms of iG-CLC power plant, recycling partial CO₂ to the fuel reactor improves the overall performance. Approximately 3.9% of net power efficiency are increased in CO₂-based plant, from steam-based plant. Higher CO₂ capture efficiency and lower CO₂ emission rate are observed in CO₂-gasified iG-CLC power plant, expecting to be 90.63% and 85.18 kg·MW^-1·h^-1, respectively.     

煤气化联合循环发电示范状况和煤气化工艺对比

煤炭气化已被确认为制取管道煤气或合成气的技术。经多方研究已被工业化规模生产和煤气化联合循环发电所证实。本文评述了煤的基本性质对气化效率的影响，煤气化联合循环发电示范厂现状和各种选定用于煤气化联合循环发电的第二代煤气化方法的对比。本文最后阐述了煤气化联合循环发电用于改造高能耗的以煤、油和天然气为燃料的中小规模电厂的现实性。     

Low-tar,highly burnable gas production from the gasification of pelletized palm empty fruit bunch

Gasification is an attractive method to convert lignocellulosic biomass into a combustible gas mixture for electricity and power generation. To control the tar concentration in the produced gas to be within the allowable limit of downstream applications, it is important for a gasification system to be integrated with a tar removal process. In this study, an integrated gasification system consisting of a downdraft gasifier and a secondary catalytic tar-cracking reactor was designed and tested for the gasification of pelletized oil palm empty fruit bunch. To further purify the producer gas, the system was also integrated with a cyclone, a water scrubber, and a carbon-bed filter. Biomass was fed at a rate of 5 kg/h, while the air equivalence ratio (ER) and the gasification temperature were set at 0.1 and 800°C, respectively. In total, 5 kg of the specially developed low-cost Fe/activated carbons (AC) catalyst was used in the hot gas catalytic tar-cracking reactor. Results indicate that our integrated gasification system was able to produce a clean burnable gas with a lower heating value (LHV) of 9.05 MJ/Nm³, carbon conversion efficiency (CCE) of 79.4%, cold gas efficiency (CGE) of 89.9%, and H₂ and CH₄ concentrations of 29.5% and 10.3%, respectively. The final outlet gas was found to only contain 32.5 mg/Nm³ of tar, thus making it suitable for internal combustion engine (ICE) application.