膜技术在沼气纯化中的应用:现状与未来

Biogas upgrading with membrane technology:An overview

沼气纯化替代天然气将是缓解能源短缺、弥补天然气需求缺口的重要途径.2005~2014年,处理量超过100m3/h（在标准状态下,全文同）的膜法沼气纯化厂从4座增长至73座,总规模从13 800m3/h扩大至127 000m3/h.目前膜法沼气纯化厂多集中在欧美地区,主要使用聚酰亚胺（PI）、醋酸纤维膜（CA）和聚砜膜（PSf）,其CO2渗透速率在2~80GPU[标准状况下,1GPU=7.5×10-10 cm3/（cm2·s·Pa）],CO2/CH4选择性在16~100之间.沼气纯化以二级和二段膜分离系统为主,操作压力在0.5~3.0 MPa之间,产气甲烷纯度和甲烷回收率均可达到98%以上.新型膜材料的研发、耦合工艺以及多杂质的同步脱除工艺的应用将是沼气纯化未来的发展趋势.

Biogas upgrading is an effective way to alleviate energy shortage and make up for the demand of natural gas.Since 2005,the number of membrane-based upgrading plants with capacity more than 100m3/h has increased from 4to 73,and the total capacity of these plants also has increased from 13 800m3/h to127 000 m3/h.Nowadays,most of the membrane-based upgrading plants are located in Europe and America.The membrane applied mainly includes cellulose acetate（CA）,polyimide（PI）and polysulfone（PSf）.Besides,the CO2 permeance of these kinds of membrane is 2~80GPU and the CO2/CH4 selectivity is 16~100.Biogas upgrading mainly chooses the two-step and two-stage membrane-based systems at operating pressure of 0.5~3MPa.Through the upgrading proceed,the methane purity and methane yield can both achieve at 98%.In the future,the developing of membrane-based biogas upgrading technology will mostly be focused on the research of new membrane materials,the application of the coupling technics and the simultaneous removal of multi-impurities.