聚丙烯中空纤维膜组件分离烟气中的CO2

摘要

This research presented separation of CO2 from flue gas by polypropylene(PP) hollow fiber membrane contactors,using aqueous solution of monoethanolamine (MEA) as absorption solvents. Effects of operating conditions,water vapor and SO2 on the performance and integrity of the membrane were investigated. The results showed that the best liquid-gas ratio was 24 L/m3,the concentration of MEA was 0.6 mol/L and temperature at the contactor entrance had little effect on absorption efficiency. The concentration of CO2 had little effect on absorption efficiency when the concentration was in the range of 10%-20%. The adsorption of SO2 is prior to CO2,but it isn’t obvious for the low concentration of SO2. Adsorption of water vapor on the hole walls of membrane contactors forms capillary condensation,preventing the penetration of CO2.%膜吸收法在大型工业燃煤电厂二氧化碳（CO2）捕集方面具有很好的应用前景，但烟气组分对该技术效果影响还有待进一步研究。本文以单乙醇胺（MEA）为吸收剂，开展了疏水性聚丙烯（PP）中空纤维膜组件分离模拟烟气中的 CO2的实验研究，考察了吸收操作条件以及燃煤烟气中水汽和 SO2对膜组件吸收效率的影响。结果表明，试验的最佳液气比为24 L/m3；MEA的浓度为0.6 mol/L；膜组件进口的温度变化对吸收效率基本没有影响；CO2的浓度在10%～20%内变动对吸收效率影响不大。与CO2相比，SO2会优先发生吸收作用，而水汽则会吸附在聚丙烯中空纤维膜组件的孔壁上，产生毛细管凝聚现象，阻塞CO2的渗透吸收。