Simulation Model for Prediction of Gas Separation in Membrane Contactor Process

The purpose of this study is to establish a practical simulation model based on mass balance, mass transport equations and equilibrium equation between gas and liquid phases across a porous membrane in membrane contactor process in order to predict the separation behavior by the gassing process of gas mixture in membrane contactor. The established simulation model was verified by comparison between the simulated values and real process values in the separation of CH₄/CO₂ mixture, showing an excellent agreement between them. The parameter R-value in the model, which is a kind of the permeability of permeant across porous membrane, has been determined by fitting a numerical solution of the model equation to the experimental data to obtain a practical value of the parameter. A parametric study on the gassing process of N₂/CO₂ mixture in membrane contactor was made with the help of the practical simulation model to investigate the effects of operation parameters on separation performance and to characterize the separation behavior of membrane contactor process. A series of simulations of the separation of N₂/CO₂ mixture in membrane contactor were conducted, and the optimization on the membrane process was discussed to maximize the separation performance in terms of N₂ recovery percent in retentate and CO₂ permeation rate. It was observed from the analysis of the result of the simulation that liquid flow rate has a negative effect on N₂ recovery percent in retentate but a positive effect on the separation of CO₂, while R-value affects the separation performance in the other way. It is confirmed in this study that the developed simulation can be used as a tool to optimize the parameters, i.e., feed gas pressure, liquid flow rate and R-value to maximize the separation performance.