Preparation of carbon molecular sieve membranes by KOH activation for gas separation

Carbon molecular sieve membranes were prepared by the pyrolysis of a mixture containing phenolic novolac resin and KOH. The effects of KOH on the properties of the membranes were investigated. Results showed that membranes with homogeneous pore size distributions and high gas permeation rates can be obtained by controlling the amount of KOH . Their H₂ gas permeability increased from 23.68×10^-10 to 28.6×10^-10mol · m^-2 · s^-1 · Pa^-1 and H₂/N₂ and H₂/CH₄ selectivity decreased from 471.3 to 147.5 and 540 to 270 respectively, while the CO₂/CH₄ and O₂/N₂ selectivity changed little with increasing KOH content in the coating solution from 0 to 4mass%.