A fluidized-bed model for NiMgW-catalyzed CO₂ methanation

The reduction of carbon dioxide to methane by hydrogen (“CO₂ methanation”) using renewable energy is a promising process for recycling CO₂. Better catalysts and better reactors are both required for the practical application of CO₂ methanation. This study examines how the operating parameters affect CO₂ methanation in a highly efficient fluidized-bed reactor. We first measured the kinetics of the CO₂ methanation reaction using an NiMgW catalyst, which has been reported to exhibit superior catalytic performance. We then developed a fluidized-bed reactor model based on an earlier model for CO₂ methanation. The fluidized bed model indicated that the NiMgW was indeed superior to two other previously studied catalysts in terms of faster conversion of reactants and higher concentrations of product CH₄ throughout the reactor. The overall rate of production of CH₄ increased with temperature and H₂/CO₂ ratio and decreased as the inlet reactant flow rate, catalyst particle diameter, and catalyst particle sphericity increased.