Numerical study on absorption of carbon dioxide and mass transfer performance in hollow fiber membrane contactor

A type of process,which absorbs carbon dioxide(CO2) from flue gas in hollow fiber membrane contactor,has been considered as one of clean,high efficient and the most promising decarburization technologies.A two-dimensional mathematical model was developed for absorption of CO2 from parallel countercurrent mixed gas by hollow fiber membrane contactor.By using finite element method,CO2 removal(decarburization) and mass transfer performance of three absorbents EEA(ethyl-ethanolamine),EDA(ethylenediamine) and PZ(piperazine) were simulated at various operation conditions in which axial and radial diffusion in membrane contactor as well as diffusion in fiber and membrane pores and non-wetting condition were considered.The simulation results show that the order of decarburization performance is PZ EDA EEA.The influence of the gas phase parameters on CO2 removal and mass transfer is more significant than that of liquid phase parameters.With increase of gas flow rate,CO2 concentration,and gas temperature,the decarburization efficiency decreases.While the CO2 removal efficiency goes up when liquid flow rate,solvent concentration,and liquid temperature increase.However,the CO2 mass transfer rate speeds up with increase of all parameters except gas temperature.So,the suitable control of liquid parameters is required,which are not over high to prevent adverse effects on CO2 absorption.