Recent Insights into the Production of Syngas and Hydrogen Using Chemical Looping-Steam Reforming (CL-SR)

Chemical looping-steam reforming (CL-SR) is a prospective technology for the simultaneous production of syngas and hydrogen (H2). The quality of syngas and hydrogen (H2) obtained from CL-SR process has garnered the interest of the scientific society. A recyclable oxygen storage material (oxygen carrier) is reacted through an alternating cycle of fuel (reduction step) and steam (oxidation step) at higher temperatures. Oxygen carrier (OC) plays a vital role in directing the path of the reaction in the CL-SR process. Hence, developing and selecting a proper OC is crucial. The current study intends to address recent breakthroughs in the development and performance of OCs subjected to different reacting fuel species such as methane (CLSMR), CO2 (CL-HG), and liquid fuels. The performance of various classes of OCs such as metal oxide, mixed metal oxides, and perovskites toward conversion and lattice oxygen selectivity is investigated. The thermodynamic study and constraints related to the performance of OCs in CL-SR are discussed along with the economic evaluation of the CL-SR process and the conventional SMR process. Further, the theoretical approaches involved in determining the kinetics of the CL-SR process and kinetic models developed by the researchers are reviewed. Finally, the scientific barriers and the suggestions for optimized operation of the CL-SR process are listed.