Effects of a Natural Zeolite on Carbon Membrane Gas Separation Performance

Supported carbon mixed matrix membranes (CMMMs) were prepared by incorporating 0.1 %, 0.5 %, and 1 % clinoptilolite zeolite (CZ), a natural inorganic material, into polyetherimide (PEI), following by pyrolysis. The CZ exhibited adequate thermal stability to withstand pyrolysis, and, for the first time, this zeolite was applied to CMMM development. The CZ affected the interlayer spacing and the organization of the carbon structures. Moreover, the adsorption properties of CZ influenced performance of CMMM. Membranes containing 0.1 % and 0.5 % CZ exhibited high selectivity for O 2 /N 2 and CO 2 /CH 4 , but a decrease in selectivity was observed in the membrane containing 1 % CZ. The membrane prepared with 0.5 % CZ demonstrated the most favorable permeability‐selectivity relationships for O 2 /N 2 and CO 2 /CH 4 separations, with selectivities of 23 and 110, respectively. This work highlights the potential of using a natural‐origin material to optimize the performance of carbon membranes for gas separation.