Recent Advances in Polybenzimidazole Membranes for Hydrogen Purification

Hydrogen has gained renewed and growing interest around the world in the recent decades as a high-quality and renewable energy carrier, owing primarily to advances in fuel cells as well as growing environmental concerns. Steam reforming of fossil-based resources is currently the main route to H2 production. The downside of this process, however, is generation of massive amounts of greenhouse gases including CO2 as the byproduct which in turn must be captured to fully exploit the potential of H2. Membrane separation technology has seen significant growth, breakthroughs, and advancements over the last few decades and could be the key component in achieving inexpensive and highly pure H2. However, only a few numbers of membrane materials can withstand the harsh conditions of H2 production through steam reforming. Polybenzimidazole (PBI)-based membranes show excellent chemical, thermal, and mechanical stabilities as well as high intrinsic H2/CO2 selectivity. The objective of this review is to overview the recent development of structurally modified, cross-linked, mixed matrix, and hollow fiber membranes based on PBI for the development of industrially applicable H2-selective membranes.