Mathematical Modeling of Simultaneous Removal of Acid Gases from Natural Gas Using a HFM Contactor in Cocurrent Flow

چکیده مقاله

A two-dimensional mathematical model was developed for the simultaneous transport of carbon dioxide and hydrogen sulfide through hollow fiber membrane (HFM) contactors using monoethanol amine (MEA) as a chemical solvent. The model considered non-wetting conditions where the gas mixture fills the membrane pores for cocurrent gas–liquid flow arrangement. Radial diffusion was considered, but axial diffusion was ignored inside the fiber, through the membrane, and within the shell. The effect of MEA concentrations, gas and liquid velocities were studied on the simultaneous removal of CO2 and H2S. The % removal of CO2 increased with increasing the MEA concentration. As for H2S, low concentration of MEA was efficient in high % removal. The % removal of CO2 decreased by increasing gas velocity, whereas, H2S % removal changed slightly with increasing gas velocity when operating at low gas velocity. However, the effect is more pronounced when operating at high gas velocities. Both CO2 and H2S % removal were increased with increasing the liquid velocity. CO2% removal increased slightly, while H2S % removal increased substantially, while operating at high gas velocity. Eventually, the results were compared to results gained from literature in countercurrent flow pattern with the same HFM and solvent. As it is expected, % removal in cocurrent flow in different MEA concentrations, gas and liquid velocities was lower than countercurrent flow.