High-Performance Ceramic Mixed-Matrix Membranes for CO2/N2 Separation: Integrating Pebax-1074, PEG-400, and ZIF-8

Abstract

The present study introduces a novel multilayer composite membrane based on a Basalt-Alumina (BA) ceramic support, a MOF (ZIF-8) as a gutter layer, and a Pebax-1074 with polyethylene glycol (PEG-400) as a selective layer, designed for CO2/N2 separation. BA (support layer) provides excellent mechanical strength and thermal stability, ZIF-8 (interlayer) facilitates the defect-free formation of the separation layer and promotes rapid gas transport. The incorporation of PEG-400 into Pebax-1074 enhances CO2 affinity through ether functional groups and increased chain mobility. The impact of PEG content on membrane efficiency was systematically examined. 20 wt% PEG-400 is the optimal content for efficient gas separation. Operating conditions were further optimized by investigating feed pressures in the range of 0-0.6 MPa and temperature ranges from 25 to 55 °C, with the optimal conditions identified as 0.3 MPa and 25 °C. The constructed Pebax-1074-PEG-400/ZIF-8@BA ceramic membrane achieved a high CO2 permeance of 5955 GPU and a CO2/N2 selectivity of 30.23, highlighting its promising potential for gas separation.

Keywords: Ceramic membrane, single-gas separation, Pebax-1074-PEG-400/ZIF-8@BA, PEG-400 plasticizer, PEG-400 content