耦合绿电煤气化生产化学品过程CO_(2)减排潜力  

Potential of CO_(2) emission reduction of coal gasification combined with green electricity

作　　者：孙益 郭啸晋 徐祥[1,2,3] SUN Yi;GUO Xiaojin;XU Xiang(Key Laboratory of Advanced Energy and Power,Institute of Engineering Thermophysics(IET),Chinese Academy of Sciences(CAS),Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;Jiangsu Zhongke Research Center for Clean Energy and Power,Lianyungang 222069,China)

机构地区：[1]中国科学院工程热物理研究所能源动力研究中心,北京100190 [2]中国科学院大学,北京100049 [3]江苏中科能源动力研究中心,江苏连云港222069

出　　处：《洁净煤技术》2024年第4期111-119,共9页Clean Coal Technology

基　　金：国家重点研发计划资助项目(2019YFE0100100)。

摘　　要：耦合可再生能源生产的绿电为煤气化反应供热以消除燃烧供热实现自热平衡的影响,不仅可有效降低气化过程CO_(2)排放量,还能提高合成气氢碳比(H/C),从而降低以煤气化为源头生产化学品的水煤气变换工段中CO_(2)排放。对不同类型的常规气化反应器和相应的耦合绿电反应器进行建模与模拟,判明合成气组分的主要影响因素,分析了温度对合成气组分的影响,探讨合成气H/C随温度变化规律,并计算不同化学品生产过程的CO_(2)减排潜力。结果表明,耦合绿电的气化反应器合成气中CO_(2)排放较常规气化反应器分别减少了12.63%(固定床)、11.01%(气流床)、9.23%(输运床)和5.12%(流化床),且H/C呈上升趋势;温度对合成气组分影响较大,热解解耦和气化反应的反应器一定程度上影响合成气组分;温度低于1500 K时,H/C随温度升高而降低;温度高于1500 K时,H/C随温度升高而缓慢升高;耦合绿电煤基化学品生产过程CO_(2)排放大幅减少,操作在更低温度和压力的气化反应器具有更高的合成气H/C和CO_(2)减排潜力;耦合绿电的固定床系统效率优势明显;考虑到耦合绿电的高温反应器存在的技术困难,耦合绿电的固定床、流化床和输运床反应器更具可行性。For the processes to produce coal-based chemicals using coal gasification processes,combining with green electricity is an effective method to achieve CO_(2)emission reduction because not only the CO_(2)emissions caused by combustion of coal to provide needed heat in gasifiers can be eliminated but also the higher hydrogen to carbon ratio(H/C)of synthesis gas can be obtained and the CO_(2)emissions in water-gas-shift unit can be reduced.The models of different conventional gasifiers were simulated and verified,and the corresponding green electric heating gasifiers were simulated.The trends on the composition of the gaseous products and the H/C of the syngas were simulated,and the influences on the products by temperature,sorts of coals,and sequence of reactor models were analyzed.Furthermore,the trends of H/C with temperature are investigated and the potential of CO_(2)emission reduction are calculated.It is found that the CO_(2)emissions of the reactors combining with green electricity decrease by 12.63%(fixed bed),11.01%(entrained flow bed),9.23%(transport bed)and 5.12%(fluidized bed),respectively.Besides,the H/C shows an upward trend.Temperature has a significant impact on the composition of syngas,and the reactors for decoupling pyrolysis and gasification reactions to some extent affect the composition of syngas.When the temperature is below 1500 K,the H/C decreases with the increase of temperature.When the temperature is above 1500 K,the hydrogen to carbon ratio slowly increases with the increase of temperature.Decoupling pyrolysis and operating under lower pressure can help to achieve a higher H/C and lower CO_(2)emission,and the gasifiers operating under more moderate conditions have more potential of CO_(2)emission reduction.The efficiency advantage of the fixed bed coupling with green electricity is obvious.Considering the technical difficulties of high-temperature reactors coupled with green electricity,fixed bed,fluidized bed,and transport bed reactors coupled with green electricity are more feasible.

关 键 词：煤气化 流程模拟 CO_(2)减排 氢碳比 绿电 

分 类 号：TQ53[化学工程—煤化学工程] TK114[动力工程及工程热物理—热能工程]