Hollow fiber membrane process for SO 2 removal from flue gas

BACKGROUND In this study, a polymeric membrane process was investigated to avoid the poisoning of CO 2 sorbents with SO 2 during the carbon capture and separation ( CCS ) process. Two types of hollow fiber composite membranes were prepared using poly(ether‐ b ‐amide) ( PEBAX ) and cellulose acetate ( CA ) as composite materials. RESULTS Both of the composite membranes exhibit a trade‐off between the pure gas permeance and the ideal selectivity. The PEBAX1657 / PEI exhibited higher permeance than CA / PES due to the morphology of the substrate and the effects of the coating material. A mixed‐gas separation experiment investigated the SO 2 removal efficiency and the CO 2 loss ratio. The SO 2 removal efficiency and CO 2 loss ratio were found to be positively correlated with the permeance of the gas components. A multi‐stage membrane process was designed to reduce the CO 2 loss ratio with a 90% removal efficiency of SO 2 . Compared with a single‐stage process, the CO 2 loss ratio was decreased by up to 16.1%, and the membrane area was estimated at 18.1 m 2 for the multi‐stage process. CONCLUSION A multi‐stage membrane process was designed using different types of membrane modules to decrease CO 2 loss ratio without sacrificing SO 2 removal efficiency. © 2014 Society of Chemical Industry