菱镁矿熔炼烟气中CO_2加氢制甲醇系统的能效分析  

Energy efficiency analysis of CO_2 hydrogenation methanol system on the smelting smoke of magnesite

作　　者：王秀 崔家骏 赵亮[1] 张晟[1] 董辉[1] Wang Xiu;Cui Jiajun;Zhao Liang;Zhang Sheng;Dong Hui(Northeastern University)

机构地区：[1]东北大学国家环境保护生态工业重点实验室

出　　处：《冶金能源》2018年第6期6-10,共5页Energy For Metallurgical Industry

基　　金：辽宁省科学技术计划项目(2015229006)

摘　　要：菱镁矿烟气中CO_2捕集后,其资源化利用是技术推广的难点。文章基于菱镁矿烟气CO_2粗排放现状,根据烟气余热和CO_2的物性特点,确定了CO_2加氢制甲醇系统工艺流程各个节点的热工参数。采用热力学第一定律和第二定律对系统进行焓分析和火用分析,找出流程中不可逆损失最大的环节,为今后流程的节能优化指明方向。研究表明:系统在反应温度为220℃、反应压力为5MPa时,CO_2转化率为27. 8%,甲醇转化率为49. 9%,甲醇产量为618. 4kg/h,系统热效率为52. 9%,火用效率为77. 8%;热损失最大的环节为膨胀机,火用损失最大的环节为混合器;反应温度上升,系统的火用效率下降,反应压力升高,系统的火用效率上升。After CO 2 capture on the smelting smoke of magnesite,the resource utilization is a difficult problem to be solved for technology popularization.Considering the present situation of CO 2 coarse emissions,according to the physical characteristics of flue gas waste heat and the feature of CO 2,the thermal parameters of process various nodes was determined.The system was analyzed by enthalpy and exergy analytical method according to the first law and second law of thermodynamics.The most maximal part of irreversible loss in the process was found.And the direction for energy saving optimization in the future was indicated.The result shows that in the condition of the reaction temperature 220℃and pressure 5 MPa,the CO 2 conversion rate is 27.8%and the conversion rate of methanol is 49.9%.The output of methanol is 618.4 kg/h.The thermal efficiency of the system is 52.9%.The efficiency of exergy is 77.8%.The part of maximal heat loss is the expansion machine,while the part of maximal exergy loss is the mixer.Along with the rising of temperature,the exergy efficiency of the system falls.When the pressure is rising,the exergy efficiency is increased.

关 键 词：菱镁矿烟气 CO2资源化 甲醇 [火用]分析 

分 类 号：TQ223.121[化学工程—有机化工]