Nanoporous Carbon Molecular Sieve Membrane Fabrication for Hydrogen Purification from Reformate Gas Streams

Abstract

Hydrogen purification from reformate gas streams is a critical process in clean energy production and industrial hydrogen utilization, requiring highly selective and energy-efficient separation technologies. This study investigates the fabrication of nanoporous carbon molecular sieve membranes for hydrogen purification from reformate gas mixtures containing carbon dioxide, methane, carbon monoxide, and nitrogen impurities. The research focuses on membrane synthesis, structural characterization, and gas separation performance under varying operational conditions. Nanoporous carbon membranes were fabricated through controlled carbonization and pore development processes to achieve selective molecular transport and enhanced hydrogen permeability. Experimental analyses were conducted to evaluate the influence of precursor composition, carbonization temperature, membrane thickness, activation conditions, feed pressure, and operating temperature on membrane morphology and separation efficiency. Results demonstrated that the fabricated carbon molecular sieve membranes exhibited high hydrogen selectivity and permeability due to their narrow pore size distribution and molecular sieving characteristics. The optimized membrane structure effectively restricted the transport of larger gas molecules while facilitating rapid hydrogen diffusion through the nanoporous network. Gas permeation studies confirmed stable membrane performance and improved separation efficiency under elevated operating pressures. Structural characterization revealed that pore architecture and carbon matrix ordering strongly influence gas transport behavior and membrane durability. Compared with conventional gas purification techniques, the proposed membrane-based process offers advantages such as lower energy consumption, compact system design, and continuous operation capability.