Performance of Multilayer Composite Hollow Membrane in Separation of CO 2 from CH 4 in Mixed Gas Conditions.

Composite membranes comprising NH 2 -MIL-125(Ti)/PEBAX coated on PDMS/PSf were prepared in this work, and their gas separation performance for high CO 2 feed gas was investigated under various operating circumstances, such as pressure and CO 2 concentration, in mixed gas conditions. The functional groups and morphology of the prepared membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). CO 2 concentration and feed gas pressure were demonstrated to have a considerable impact on the CO 2 and CH 4 permeance, as well as the CO 2 /CH 4 mixed gas selectivity of the resultant membrane. As CO 2 concentration was raised from 14.5 vol % to 70 vol %, a trade-off between permeance and selectivity was found, as CO 2 permeance increased by 136% and CO 2 /CH 4 selectivity reduced by 42.17%. The membrane produced in this work exhibited pressure durability up to 9 bar and adequate gas separation performance at feed gas conditions consisting of high CO 2 content.