Issues and challenges in hydrogen separation technologies

Depleting energy resources, global warming and environmental problems associated with conventional fuels are serious global challenges of the modern world. The substitution of conventional energy resources with more efficient and sustainable resources is inevitable. In this scenario, hydrogen (H2) has emerged as the ultimate choice due to its superior characteristics such as low carbon emissions, cleanliness, and efficiency. However, for the successful implementation of making H2 as the next-generation fuel source, the hurdles of production, separation, and storage of H2 should be resolved. This paper summarizes the issues and challenges in the separation of H2 gas from various production streams by using available separation technologies. Different types of H2 separation technologies, including membranes, adsorption processes, metal hydrides, and cryogenic separation technologies, have been considered and discussed. The review encompasses the types, advantages, and disadvantages of each technology, followed by a detailed account of issues and challenges observed in each separation method. More attention has been given to membrane technology because it is the most promising technology for the production of high-purity H2. Finally, this review provides an outlook for future directions and developments in H2 separation technologies. [Display omitted] •Hybrid separation systems are required to meet the purity levels of H2.•Optimization of the metallic membrane (heat treatment) should be taken into account.•Multi-objective optimization strategies must be studied in PSA adsorbents.