CFD simulation of CO2 capture from gas mixtures in nanoporous membranes by solution of 2-amino-2-methyl-1-propanol and piperazine

A two-dimensional model for the mass transport of carbon dioxide from the gas mixture in nanoporous membrane contactors was developed in this work. A solution of 2-amino-2-methyl-1-propanol and piperazine (activator of absorption) is used as a chemical solvent for capture of CO2. The diffusion in the radial and axial direction of the fibers, through the membrane and the shell of membrane contactor was investigated. The convection inside the tube and shell was also investigated along with chemical analysis. Computational fluid dynamics technique was used to solve the model equations including continuity and momentum equations. The predictions of the model were compared with the experimental data and good agreements were observed which confirmed the validity of developed mass transfer model. According to the presented results, an increase in the gas and liquid flow rate results in an increase in the rate of CO2 absorption (at NRe < 20). Also, an increase in the concentration of piperazine results in an increase in the CO2 absorption of the gas mixture. This study indicates that the proposed model is capable of predicting the rate of CO2 capture in membrane contactors with good precision.