生物质氧气−蒸汽自热气化制取合成气过程能量−㶲分析  

Energy and Exergy Analysis of Autothermal Biomass Gasification Process with O2-Steam Mixture for Syngas Production

作　　者：谭烽华 李宇萍[1] 彭建刚[1] 罗伟民[1] 董凯军[1] 龙金星[3] TAN Fenghua;LI Yuping;PENG Jiangang;LUO Weimin;DONG Kaijun;LONG Jinxing(Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]中国科学院广州能源研究所,广州510640 [2]中国科学院大学,北京100049 [3]华南理工大学化学与化工学院,广州510641

出　　处：《新能源进展》2023年第4期340-347,共8页Advances in New and Renewable Energy

基　　金：国家重点研究计划项目(2019YFB1503905);国家自然科学基金项目(51776205)。

摘　　要：针对生物质气化制备合成气效率低、有效能分析不完善现状,提出以氧气−蒸汽为气化剂的自热气化系统,对该系统进行了模拟,建立热力学评价系统能量和㶲效率方法,重点分析未气化焦炭利用、氧气及蒸汽与原料质量比(O/B和S/B)和原料含水量对系统性能影响。结果表明,焦炭利用可大幅度提高合成气能量效率,但由于焦炭燃烧过程的㶲损失,使得系统总㶲效率降低。对高温气化气进行热量回收,产生的300℃蒸汽用于气化,可使S/B比达0.36以上,合成气氢碳比(H_(2)/CO)达1.63,收率达1.18m^(3)/kg。系统总㶲效率和合成气㶲效率随气化S/B比增大而稍微降低,分别在74%和69%以上,但系统总能量效率显著降低,说明热量回收对提高系统总能量效率的重要作用,为提高系统总㶲效率,还应提升回收能量的品位。含水量为30%的生物质比较适合合成气制备。In view of the inadequate efficiency of biomass gasification for syngas production and the lack of exergy analysis,an autothermal biomass gasification process with O2-steam was proposed and simulated in this study.The thermodynamic performance was studied and evaluated via the energy and exergy method.The effect of operation parameters was investigated,including the usage ratio of ungasified char,the mass ratios of O2 to biomass(O/B)and steam to biomass(S/B),and the moisture content of biomass.The results indicated that the high usage ratio of char significantly enhanced the energy efficiency for syngas production.However,the overall exergy efficiency decreased due to exergy losswithin char combustion operation.Heat integration was designed by cooling high temperature gasification gas for steam generation(300 oC),which was introduced to the gasifier and resulted in ahigh S/B ratio of above 0.36 for gasification.Therefore,ahigh syngas yield of 1.18m^(3)/kg was obtained with H_(2) to CO ratio of 1.63(H_(2)/CO).With the increase of S/B ratio,the overall system exergy efficiency and syngas exergy efficiency slightly decreased,which was above 74%and 69%respectively.However,the overall system energy efficiencydecreased,indicating heat recovery’scritical effect on system thermal performance.Various heat integration strategies should be explored to improve the recovered heat’s energy grade and increase system exergy efficiency.The feedstock with 30%moisture content was proper for syngas production.

关 键 词：生物质 自热气化 氧气−蒸汽 合成气 能量−㶲分析 

分 类 号：TK6[动力工程及工程热物理—生物能] TQ546[化学工程—煤化学工程]