电厂烟气中CO2膜法分离实验研究与模拟计算

Experimental Study and Numerical Simulation on CO2Separation from Power Plant Flue Gas by Membrane Method

为掌握中空纤维膜对电厂烟气中低体积分数CO2的分离效果,搭建了单级膜CO2分离系统,并对影响该系统分离性能的进口气压力、进口气总体积流量、进口气组分体积分数和膜组件温度等因素进行了实验研究。对分离膜组件建立了简化数学模型,并分析了模型计算值与实验值之间的误差。结果表明:渗透气CO2的体积分数随进口气总体积流量和进口气CO2体积分数的增大而增大,随进口气压力的升高而减小,膜组件温度的上升对渗透气CO2的体积分数基本无影响;系统CO2的回收率随进口气压力升高、进口气CO2体积分数的增大以及膜组件温度的升高而增大,随进口气总体积流量的增加而降低;在工程允许的误差范围内,模型计算值可以较好地描述实验结果,并且模型应用简单,可为膜法分离CO2的工艺设计提供计算基础。

To study the effects of hollow fiber membrane on the separation of low concentration CO2from power plant flue gas,a single-stage membrane separation system was built,based on which,the factors affecting the separation performance of the system were studied experimentally,such as the pressure and total flow rate of inlet gas,the volume fraction of various components in inlet gas and the temperature of membrane module,etc.In addition,a simplified mathematical model was established for the separation membrane module,while the relative errors between the calculated results and experimental data were analyzed.Results show that the volume fraction of CO2in permeable gas increases with the rise of both the total flow rate of inlet gas and the volume fraction of CO2in inlet gas,and decreases with the increase of the inlet gas pressure.The increase in temperature of the membrane module has little effect on the volume fraction of CO2in permeable gas.The recovery rate of CO2in the system increases with the rise of the inlet gas pressure,the volume fraction of CO2in inlet gas and the temperature of the membrane module,and decreases with the increase of the total flow rate of inlet gas.The calculation results agree well with the experimental data within the allowable error range,and the model is easy to be applied.This may serve as a calculation basis for the process design of CO2separation by membrane method.