水汽对膜法捕集CO2的影响

Effects of water vapor on membrane CO2 capture

为了考察水汽单独存在及与SO2或颗粒物共存时对聚酰亚胺(PI)分离膜和聚丙烯(PP)吸收膜捕集CO2性能的影响规律,利用自行搭建的CO2膜捕集试验台进行了研究。结果表明:在试验条件下,当烟气的相对湿度达到90%时,PI分离膜对CO2/N2的分离因子略有上升,但渗透速率下降,PP膜的CO2吸收效率下降7%,经N2反吹后,PI膜和PP膜的捕集效率均能得到恢复;水汽与SO2共存,PI分离膜的CO2/N2分离因子和渗透速率分别下降5.64%和24.54%,PP吸收膜脱除效率下降18%,但经N2反吹及膜丝实验前后红外测试表明水汽与SO2共存对PI膜和PP膜性能造成的影响都是可逆的;水汽与颗粒物共存时,PI分离膜的CO2/N2分离因子和渗透速率分别下降39.79%和49.82%,PP吸收膜脱除效率下降18.9%,通过N2反吹分析水汽和颗粒物共存对PI分离膜和PP膜造成的影响不可逆。

Effects of water vapor and mixtures of water vapor/SO2 or water vapor/particles on CO2 capture using polyimide(PI) and polypropylene(PP) membranes were investigated by a lab-made membrane CO2 capture setup.The results show that when studied under 90% relative humidity of flue gas,the CO2/N2 separation factor of the PI separation membrane increases slightly but the penetration rate decreases, and the absorption efficiency of the PP membrane decreases by 7%. The capture efficiencies of PI and PP films restore after N2 back flushing.When studied using SO2 and water vapor mixtures, the CO2/N2 separation factor and permeation rate of the PI membrane reduced by 5.64% and 24.54%, respectively,and the removal efficiency of the PP membrane decreased by 18%.Moreover, when studied using particle and water vapor mixtures, the CO2/N2 separation factor and permeation rate of the PI membrane reduced to 39.79% and 49.82%, respectively,and the removal efficiency of the PP membrane decreased by 18.9%.However,the results of N2 back blowing experiments show that the coexistence of water vapor and SO2 has reversible effects on the PI and PP films,while the effect of the coexistence of water vapor and particles is irreversible.