聚酰亚胺中空纤维膜分离CO2/N2的影响因素分析

Study on influencing factors of polyimide hollow fiber membrane on CO2/N2 separation

膜分离法以其对环境友好、能耗低等优点逐渐成为气体分离提纯的重要途径之一,利用聚酰亚胺中空纤维膜,以CO2/N2混合气体模拟燃煤烟气,研究了烟气温度、流量、CO2浓度及膜组件滞留端压力等条件对聚酰亚胺膜分离烟气中CO2效果的影响。实验结果表明:单级膜分离法脱碳效率较低,无法全部回收烟气中的CO2,适用于烟气预处理及处理小流量且对脱碳效率要求不高的工艺;在条件允许的情况下,压力越高、温度越高、流速越低,膜对CO2分子的选择性越强,此时膜分离的脱碳效率越高。

Membrane separation method has gradually become one of the important ways of gas separation and purification due to its advantages of environmental friendliness and low energy consumption. In this paper, polyimide hollow fiber membrane was used, CO2/N2 mixed gas was used to simulate the flue gas after coal combustion, and the effects of flue gas temperature, flow rate, CO2 concentration and the pressure at the retention end of the membrane module on the CO2 effect in the flue gas separation were studied.Experimental results show that the single stage membrane separation process is less efficient, and the CO2 in the gas can’t be fully recovered, which is applied to the process of the gas and to process the small flow and to be less efficient at the carbon efficiency;Moreover, the higher the pressure, the higher the temperature, and the lower the flow rate, the stronger the selectivity of the membrane to CO2 molecules, and the higher the decarbonization efficiency of the membrane separation.