Progress in in-situ CO₂-sorption for enhanced hydrogen production

Deployment of fossil fuels to quench the energy demand of the world's rising population results in elevated levels of greenhouse gas (GHG) emissions, especially CO₂, which in turn is responsible for undesirable climate change. This necessitates a shift toward cleaner energy resources such as hydrogen. Enhanced hydrogen production via steam reforming of diverse fuels (methane, biomass, organic wastes, etc.) with in-situ CO₂-sorption seems to be a promising alternative. Leading-edge, innovative and eco-friendly pathways coupled with high process efficiencies are needed for the development and growth of this technology. This review article evaluates the fundamental concepts such as criteria for CO₂ uptake, mechanisms, thermodynamics and kinetics of the water gas shift reaction along with different modeling methods for sorption enhanced processes. Moreover, research works carried out worldwide at lab-scale coupled with process development and demonstration units are discussed as a means to encourage this pathway for H₂ generation. Furthermore, light is shed on techno-economics as an approach to improve the viability and sustainability of the proposed technology. This paper analyzes different dimensions of the CO₂-sorption enhanced process to promote it as a potentially carbon-neutral and eco-friendly pathway for hydrogen production.