Separation of biogas using newly prepared cellulose acetate hollow fiber membranes

The highly selective cellulose acetate (CA) asymmetric hollow fiber membranes were prepared via a dry/wet spinning process with NIPS from dope solutions containing NMP as a solvent and THF and EtOH as a non-solvent and coated with PDMS. The prepared CA hollow fiber membranes showed excellent selectivity about 37.0 for CO2 and CH4 at optimized condition (23 wt% CA, 62 wt% NMP, 10 wt% THF, 5 wt% EtOH, and 15 cm air-gap) and 5 wt% PDMS coating. The newly prepared CA hollow fiber membranes were applied to CO2/CH4 separation. The newly prepared CA hollow fiber membranes showed much better performance than the existing commercial membranes.