Precombustion CO2 Capture in Polymeric Hollow Fiber Membrane Contactors Using Ionic Liquids: Porous Membrane versus Nonporous Composite Membrane

In the present work, membrane contactors using both porous and nonporous polymeric hollow fiber membranes with ionic liquids as absorbent were developed for precombustion CO2 capture at elevated temperature and pressures. 1-Butyl-3-methylimidazolium tricyanomethanide [Bmim][TCM] was selected as the ILs absorbent. The compatibility and stability of six different polymeric membranes were evaluated, while the porous PTFE membrane and nonporous Teflon-PP composite membrane were considered to be the most suitable membranes for this application. Both membrane configurations were tested and showed comparable separation performances: CO2 flux values of 4.86 × 10–4 and 4.75 × 10–4 mol m–2 s–1 were obtained for the porous PTFE and nonporous Teflon-PP membrane contactor at 20 bar with a gas flow rate of 200 mL min–1, respectively. The Teflon-PP composite membrane exhibited better stability as compared to the porous PTFE membrane in a 14 day test.