(446b) High-Efficiency Separation of H2/CH4 and He/CH4 Using Ultraselective Carbon Molecular Sieve Membrane

Safe blending of hydrogen into existing natural gas pipeline networks is a promising strategy for low-cost hydrogen transportation. To ensure high purity hydrogen at the point of use, developing efficient separation technologies is crucial. Another market involves He/CH₄ separation to simplify extraction from natural gas sources. This study presents an ultraselective hollow fiber carbon molecular sieve (CMS) membrane that demonstrates excellent separation performance for both H₂/CH₄ and He/CH₄ mixtures. The CMS membrane was fabricated using a Matrimid® hollow fiber precursor with a 150 nm top separation layer, resulting in excellent separation efficiencies. Specifically, the membrane achieves a hydrogen purity of 99.6% with a permeance of 16.4 GPU for a 10% H₂/90% CH₄ feed mixture, and a helium purity of 99.3% with a permeance of 6.0 GPU for a 5% He/95% CH₄ feed mixture. These results underscore the potential of CMS membranes for ultraselective gas separations, contributing to both hydrogen and helium recovery in natural gas systems.