CO、CO_(2)及其混合物加氢转化制甲烷的热力学平衡研究  

A thermodynamic consideration on the synthesis of methane from CO,CO_(2),and their mixture by hydrogenation

作　　者：王晗 郭淑佳 秦张峰[1] 李志凯[1] 王国富[1] 董梅[1] 樊卫斌[1] 王建国 WANG Han;GUO Shujia;QIN Zhangfeng;LI Zhikai;WANG Guofu;DONG Mei;FAN Weibin;WANG Jianguo(State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院山西煤炭化学研究所煤炭高效低碳利用国家重点实验室,山西太原030001 [2]中国科学院大学,北京100049

出　　处：《燃料化学学报（中英文）》2024年第10期1453-1461,共9页Journal of Fuel Chemistry and Technology

基　　金：国家重点研发计划(2020YFB0606404);国家自然科学基金(21991092,22272195,U2003123,U1910203)资助。

摘　　要：由CO和CO_(2)加氢制甲烷是现今氢能储存及燃料和化学品可持续生产的有效途径之一,但目前对该反应过程(尤其是针对CO和CO_(2)混合物加氢)的一些细节尚不明晰。为此,作为前期有关CO和CO_(2)加氢制烃和醇研究工作的补充,本工作对CO和CO_(2),尤其是两者混合物的加氢制甲烷反应过程进行了热力学分析。结果证实,与单独CO或CO_(2)相比,两者混合物加氢制甲烷更为合适,总碳基甲烷收率可作为评估甲烷合成反应过程效率的重要指标。CO加氢的甲烷平衡收率比CO_(2)加氢的高,而CO和CO_(2)混合物加氢的总碳基甲烷平衡收率位于两者之间;对于CO和CO_(2)混合物加氢,尽管CO和CO_(2)的平衡转化率随进料组成不同会有很大的变化,但其总碳基甲烷平衡收率随着原料中CO_(2)/(CO+CO_(2))物质的量比的增大而线形降低。整体上看,在温度低于400℃和压力高于0.1 MPa时,无论是CO、CO_(2)、还是两者混合物的化学计量比加氢,其总碳基甲烷平衡收率均高于85%。这些结果无疑对高效CO和CO_(2)加氢制甲烷催化剂研制及反应过程的设计和操作优化有重要的参考价值。The synthesis of methane from CO and CO_(2)by hydrogenation is now considered as a promising route in effectively storing hydrogen energy as well as sustainably producing fuels and chemicals,while many reaction details involved in such processes,in particular for the hydrogenation of the CO and CO_(2)mixture,are not yet adequately understood.As a supplement to our previous works on the hydrogenation of CO and CO_(2)into alcohols and hydrocarbons,a thermodynamic consideration is made in this work to evaluate the potential and limit for the synthesis of methane from CO,CO_(2),and their mixture in particular.The results consolidate that in comparison with single CO or CO_(2),their mixture is probably more credible in practice for the production of methane by hydrogenation,where the overall C-based methane yield can be used as the major index to evaluate the process efficiency.The hydrogenation of CO shows a higher equilibrium yield of methane than the hydrogenation of CO_(2),while the overall C-based equilibrium yield of methane for the hydrogenation of the CO and CO_(2)mixture just lies in between and decreases almost lineally with the increase of the CO_(2)/(CO+CO_(2))molar ratio in the feed,despite the great change in the equilibrium conversions of CO and CO_(2)with the feed composition.Nevertheless,an adequate overall C-based equilibrium yield of methane(>85%)can be achieved at a temperature lower than 400℃and a pressure higher than 0.1 MPa for the stoichiometric hydrogenation of CO,CO_(2),or their mixture whichever.These results should be beneficial to the design of more efficient catalysts and processes for the hydrogenation of CO and CO_(2)to methane.

关 键 词：热力学平衡 CO_(2)加氢 CO加氢 甲烷化 总碳基收率 CO和CO_(2)混合物 

分 类 号：O643.36[理学—物理化学]