Regeneration strategies of deactivated catalysts for thermo-catalytic decomposition process in a fluidized bed reactor

The present article addresses on the possibility of carrying out a two-stage operation for hydrogen production from methane Thermo-Catalytic Decomposition (TCD) in a fluidized bed, consisting into first operating the reactor for methane decomposition, until a defined catalyst deactivation degree is approached, and then operating the fluidized bed as a combustor or a gasifyer for catalyst regeneration by carbon removal. Three different strategies of catalyst regeneration, carbon combustion in air, CO2 gasification and steam gasification, have been analyzed. The regeneration strategies have been compared on the basis of the efficiency of carbon removal and the performances of regenerated catalyst with respect to the TCD process. The effect of multiple cycles of decomposition and regeneration steps has been also quantified. A reasonable cyclic process has been simulated switching between two different feeds, the first containing CH4 and the second containing air. The effect of different air regeneration times on the product distribution in the CH4 decomposition phase has been tested to individuate its optimal value.