二氧化碳加氢制甲醇过程热力学分析  

Thermodynamic analysis of CO_2 hydrogenation to methanol

作　　者：祝贺[1] 汪丹峰[1] 陈倩倩[1] 沈国飞[1] 唐志永[1] 

机构地区：[1]中国科学院上海高等研究院,上海201210

出　　处：《天然气化工—C1化学与化工》2015年第3期21-25,共5页Natural Gas Chemical Industry

基　　金：中国科学院战略性先导科技专项(XDA02000000)

摘　　要：CO2加氢制甲醇是温室气体CO2资源化一个极具前景的研究领域，本文采用吉布斯自由能最小法耦合非理想体系PR状态方程对反应过程进行了热力学平衡分析。结果表明，提高压力和降低温度有利于反应的进行，有利于提高CO2的转化率，同时提高了CH3OH的选择性；增加原料n（H2）/n（CO2）有利于提高CO2的转化率和CH3OH的选择性。另外，适当添加少量CO作为原料，CO可能从产物转变为反应物，因此虽然降低了反应过程CO2的转化率，但能够增加单位CO2的CH3OH产率，不过，若原料气中CO含量过多，则CO2加氢过程转变为传统的CO加氢过程；由于反应过程受热力学平衡的制约，CO2单程转化率较低（约20%~30%），采用尾气循环的工艺过程能够成倍提高CO2总转化率。The greenhouse gas CO2 hydrogenation to methanol was a very promising research area for CO2 utilization. Thermodynamic equilibrium of CO2 hydrogenation to methanol was analyzed using the Gibbs free energy minimization with PR state equation. It indicates that CO2 conversion and the selectivity of methanol would increase with the increase of reaction pressure and H2/CO2 molar ratio in the feed gas and the decrease of reaction temperature. The methanol yield per mole CO2 increased, though CO2 conversion decreased, with the addition of a small amount of CO into the feed gas. Yet, CO 2 hydrogenation would be replaced by CO hydrogenation if an excessive amount of CO was added into the feed gas. Due to thermodynamic equilibrium restriction, CO 2 one-pass conversion was low （20%-30%）. The total CO2 conversion could be doubled when the exhaust gas recycling process was adopted.

关 键 词：二氧化碳 资源化 加氢 甲醇 热力学 吉布斯自由能最小法 

分 类 号：O642[理学—物理化学] TQ013.1[理学—化学]