Investigation of the structure and CO2/N2 separation performance of PEBA membrane by molecular simulation study

In this work, the structure of a poly ether block amide (PEBA) polymeric membrane was investigated using molecular simulation study. This membrane performance for the separation of CO2 from N2 was evaluated. In this regard, the density and fractional free volume (FFV) for this membrane were calculated and compared with experimental data. The results showed the conformity of the molecular simulation results with experimental work results. In addition, the mobility of PEBA chains and its polyether and polyamide parts were measured on a molecular scale which cannot be measured on a laboratory scale. Then the diffusion and solubility coefficients of gases were determined for this membrane and the permeability of CO2 and CO2/N2 selectivity were calculated. The performance properties of the simulated membrane showed that, solubility has a greater role in CO2/N2 selectivity than diffusivity in this membrane, so that CO2 permeability and CO2/N2 selectivity were 116.9 and 130 Barrer, respectively.