Among the available techniques for hydrogen production, the sorption enhanced steam reforming (SESR) is an emerging technology consisting in the integration of reforming reaction (H2 production) and selective separation (CO2 sorption) in a single step, to shift thermodynamically the reforming reaction and increase hydrogen production. The key element for a successful SESR process is the selection of suitable high-temperature CO2 sorbents. This review focuses on the main characteristics and preparation methods of CaO-based and alkaline-based sorbents, their advantages and drawbacks, the available techniques to improve their behavior in severe operating conditions, as well as the progress of their application in two important SESR processes, namely sorption enhanced steam methane reforming (SESMR) and sorption enhanced steam glycerol reforming (SESGR).
