摘要
以聚醚共聚酰胺(Pebax)为分离层膜材料,采用浸渍涂覆法制备复合气体分离膜,考察了Pebax复合膜对CH4、CO2和H2S等纯气以及一系列浓度的CO2/CH4混合气的渗透分离性能,并采用螺旋卷式膜分离器错流模型模拟分析Pebax气体分离膜用于沼气提纯的技术可行性.实验结果表明,Pebax膜具有较高的CO2渗透通量和CO2/CH4分离系数.由于CO2的增塑作用,复合膜对CO2/CH4混合气的分离系数小于其理想分离系数;不同浓度混合气中CO2与CH4的渗透通量随原料气中CO2分压的增大而增大,而与原料气中CO2的浓度无关.Pebax单级膜分离的沼气提纯效果受切割比、压力比等操作条件以及原料气组成等因素的影响,通过设计两级Pebax膜分离工艺可将CH4富集到95%以上,同时回收90%的CH4,改进膜工艺参数可获得更高的提纯效果,证明Pebax复合气体分离膜用于沼气提纯CH4是可行的.
Poly(amide-6-b-ethylene oxide)(Pebax)copolymer is used to prepare composite membranes by dip-coating method for biogas purification.The permeation performance of pure gases and CO2/CH4 mixture gases in Pebax composite membranes is investigated.A cross flow mathematical model of spiral-wound membrane module is used for the feasibility analysis of membrane separation technology for biogas purification.Pebax composite membrane has high CO2 permeation flux and CO2/CH4 selectivity.Due to the CO2 induced plasticization effect,the real CO2/CH4 selectivity is lower than the ideal selectivity.The gas permeation fluxes of both CO2 and CH4 increase with the increase of CO2 partial pressure,while irrelevant to the CO2 concentration.The biogas purification effects of single stage Pebax composite membrane are greatly influenced by stage cut,pressure ratio,and feed CH4 concentration.By a two-stage membrane separation process,the CH4 concentration can be enriched to 95%with a recovery of 90%.A higher purification effect can be achieved by improving the membrane technology parameters.Pebax composite membrane is feasible for biogas purification.
作者
任晓灵
任吉中
刘欣艳
REN Xiaoling;REN Jizhong;LIU Xinyan(Beijing Key Laboratory of Municipal Solid Waste Testing Analysis and Evaluation, Beijing Institute of Urban Management, Beijing 100028, China;Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China)
出处
《膜科学与技术》
CAS
CSCD
北大核心
2020年第2期82-88,111,共8页
Membrane Science and Technology
基金
国家自然科学基金(NF21406428)。
