基于碳分子筛吸附剂的CH_(4)/N_(2)变压吸附工艺研究  

Process research on CH_(4)/N_(2) pressure swing adsorption based on carbon molecular sieve adsorbents

作　　者：梁力友 鲁德华 袁英 陈禹嘉 潘峰 姚中华 黄晨 李旭 LIANG Liyou;LU Dehua;YUAN Ying;CHEN Yujia;PAN Feng;YAO Zhonghua;HUANG Chen;LI Xu(State Key Laboratory of Industrial Vent Gas Reuse,National Engineering Research Center for C1 Chemistry,Southwest Institute of Chemical Co.,Ltd.,Chengdu 610225,Sichuan,China)

机构地区：[1]西南化工研究设计院有限公司工业排放气综合利用国家重点实验室,国家碳一化学工程技术研究中心,四川成都610225

出　　处：《低碳化学与化工》2024年第6期115-121,128,共8页Low-Carbon Chemistry and Chemical Engineering

基　　金：四川省自然科学基金(2023NSFSC0111)。

摘　　要：变压吸附(PSA)法是一种用于CH_(4)/N_(2)混合气分离的成熟技术,现有研究多集中于CH_(4)含量(体积分数,下同)较低(10%~50%)的混合气的分离提纯,需要针对CH_(4)含量较高(≥70%)的CH_(4)/N_(2)混合气,开发出以碳分子筛为主要吸附剂的PSA技术。利用PSA静态测试与单塔模拟实验筛选出了分离系数高、吸附容量高的碳分子筛,再采用多塔模拟实验确定与之配套的工艺条件,通过改变吸附时间、吸附压力及工艺步序等参数得到了最佳工艺条件。结果表明,采用5-1-2/V工艺步序,吸附压力为0.5 MPa,吸附70 s,两次均压,一均压时间60 s,二均压时间10 s,逆放至常压,逆放20 s,抽真空70 s至真空度-0.092 MPa为最佳多塔模拟工艺条件,在该条件下可将产品气中CH_(4)含量提高至天然气管道输送要求(CH_(4)含量≥95%,N_(2)含量≤5%),CH_(4)收率达到68%。Pressure swing adsorption(PSA)is a mature technology,which has been widely used in separation of CH_(4)/N_(2) mixture gas.Existing researches mostly focus on the separation and purification of mixture gas with low(10%~50%)CH_(4) content(volume fraction,the same below).Therefore,it is necessary to develop a PSA technology with the carbon molecular sieve as the main adsorbent for CH_(4)/N_(2) mixture gas with high CH_(4) content(≥70%).Carbon molecular sieves with high separation coefficient and high adsorption capacity were screened by PSA static experiment and single-tower simulation experiment,and the multiple-towers simulation experiment was used to establish the best process conditions.The best process conditions were obtained by changing parameters such as adsorption times,adsorption pressure and process steps.The results show that,the best multiple-towers simulation process conditions are process steps of 5-1-2/V,adsorption pressure of 0.5 MPa with 70 s,two stages of equalizing pressure,the first equalization pressure pressurization time of 60 s,the second equalization pressure pressurization time of 10 s,inverse releasing to normal pressure with 20 s and vacuum to -0.092 MPa with 70 s.Under the optimal conditions,the CH_(4) concentration of product gas can be increased to the natural gas pipeline transmission requirements(CH_(4) content≥95% and N_(2) content≤5%),and the yield of CH_(4) is 68%.

关 键 词：变压吸附 碳分子筛 CH_(4)/N_(2)分离 多塔模拟实验 

分 类 号：TQ028[化学工程]