A Simple and Effective Method to Fabricate Separation Membranes for Dehydration of Natural Gas

PBT/PEG(1000) composite membranes were prepared by the phase inversion method and were used to dehydrate natural gas. In this study, evaporation time, coagulation bath concentration, and additives in casting solution were investigated, respectively, on the selectivity and permeability of separation membranes, and optimal conditions were found to include an evaporation time of 30 sec, an 100% PEG(400)-containing coagulation bath and 2% of PVA used as the additive. The H2O/CH4 selectivity reached over 3600, which is about 20 times more selective than the original membrane. It provides a simple and effective preparation method to fabricate membranes for dehydration of methane gas.