中空纤维膜分离烟气CO2工艺模拟优化

Simulation and optimization of hollow fiber membrane separation process for separating CO_2 from flue gas

为了分离燃煤电厂烟气中的二氧化碳,基于Matlab软件的Simulink组件对三级中空纤维膜装置进行模拟优化。建立了中空纤维膜的数学模型,使用Matlab软件编程;并针对经过预处理后CO_2体积分数15%,气量50 000 m^3/h的电厂烟气,在Simulink组件中模拟了分离工艺流程。膜材料采用经过氟化改性的聚酰亚胺6FDA/TAPA[六氟二酐/三(4-氨基苯基)胺)]。研究结果表明:随着膜面积和压力的增加,产品气中CO_2体积分数与CO_2回收率呈反比关系;所需的一、二、三级膜面积分别为42 000,50 000,5 200 m^2,需要的压缩机压力为一级0.7 MPa、二级0.65 MPa、三级1.5 Ma。最终得到的CO_2产品气流量为6 648.81 m^3/h,CO_2纯度86.88%,CO_2回收率77.02%,在满足分离要求的同时降低了碳排放。

In order to separate carbon dioxide from flue gas of coal-fired power plant, the Simulink module based on Matlab soft-ware is used to simulate the three stage hollow fiber membrane device. The mathematical model of hollow fiber membrane is estab-lished ,the program is edited by Matlab software; for the flue gas with the C02 concentration of 15% and gas flow of 50 000 m3/ h after pretreatment, the separation process is simulated in Simulink. Membrane materials are made of 6FDA-TAPA （ hexafluorodianhydride- tri^l-aminophenyl amine） , which is a kind of hyperbranched polyimide modified by fluoride. The results show that with the increase of membrane area and pressure, the concentration of C02 in the product gas is inversely proportional to the recovery of C02; the required three-level membrane area follows by 42 000 m2, 50 000 m2 and 5 200 m2, the required three-stage compressor pressure follows by 0. 7 MPa, 0. 65 MPa and 1.5 MPa. In the final C02 product gas, the flow rate is 6 648. 81 m3/h, the C02 purity is 86. 88% , the C02 re-covery rate is 77. 02% , which satisfies the separation requirement and reduces the carbon emission.