Development of polyetherimide mixed-conductor membranes for hydrogen separation

Polymeric membranes can provide an energy-efficient solution for gas separation such as hydrogen recovery. Nevertheless, the membrane performance is limited by the trade-off phenomenon between permeability and selectivity. The addition of fillers such as zeolite can overcome this constraint. However, it is difficult to reproduce the membrane due to the agglomeration of zeolite. In this work, mixed conductors such as BaCe_0.9Y_0.1O_3−δ (BCY) and La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ (LSCF) were selected as fillers because they have less agglomeration effect. The fillers were added to polyetherimide and tested for hydrogen separation from methane. The results show that BCY was not compatible with PEI due to the formation of excessive holes. However, adding 5 wt% LSCF doubled the hydrogen permeance with a boost in selectivity from 9 to 16. Characterization techniques showed no sign of particle agglomeration or surface defects.