Metal Hydrides-Based Hydrogen Purification Systems—A Review

Abstract

This review investigates the critical role of purification for enabling the use of hydrogen from various production pathways. A comparison of purification technologies indicates that metal hydrides-based hydrogen purification processes could offer an effective, energy-efficient, and cost-effective alternative to established pressure swing adsorption methods, with applicability across both small and large industrial scales. Remaining technical challenges to facilitate the translation of metal-hydrides for hydrogen purification are identified. These includes: (i) the development of better impurities-resistant hydrides of high storage capacities and rapid hydrogen kinetics, (ii) alternative pressure vessel materials capable of not only withstanding hydrogen embrittlement (HE) but also impurities driven corrosion, and (iii) better vessels architectures and engineering solutions to minimize the energy required to support metal-hydrides purification process. The need for real-time hydrogen quality monitoring is also emphasized for enhancing recovery rates and operational controls. Finally, a review of commercial products and demonstration projects highlights the potential of metal hydrides for simultaneous hydrogen purification, storage, and transport, outlining the unique capabilities of these materials.