Combined Methane Pyrolysis and Solid Carbon Gasification for Electrified CO 2 -Free Hydrogen and Syngas Production

The coupling of methane pyrolysis with the gasification of a solid carbon byproduct provides CO 2 -free hydrogen and hydrogen-rich syngas, eliminating the conundrum of carbon utilization. Firstly, the various types of carbon that are known to result during the pyrolysis process and their dependencies on the reaction conditions for catalytic and noncatalytic systems are summarized. The synchronization of the reactions’ kinetics is considered to be of paramount importance for efficient performance. This translates to the necessity of finding suitable reaction conditions, carbon reactivities, and catalysts that might enable control over competing reactions through the manipulation of the reaction rates. As a consequence, the reaction kinetics of methane pyrolysis is then emphasized, followed by the particularities of carbon deposition and the kinetics of carbon gasification. Given the urgency in finding suitable solutions for decarbonizing the energy sector and the limited information on the gasification of pyrolytic carbon, more research is needed and encouraged in this area. In order to provide CO 2 -free hydrogen production, the reaction heat should also be provided without CO 2 . Electrification is one of the solutions, provided that low-carbon sources are used to generate the electricity. Power-to-heat, i.e., where electricity is used for heating, represents the first step for the chemical industry.