A novel microwave heating-assisted reactor for industrial-scale syngas production

Syngas, i.e., a mixture made of carbon monoxide and hydrogen, is a valuable feedstock to produce different chemicals, e.g., methanol. In our recent study (Khodabandehloo et al., Int. J. Hydrogen Energy 71 (2024) 1380–1391), we demonstrated the efficacy of syngas production through chemical looping dry reforming of methane heated by microwave. However, installing a large number (typically over a hundred) of microwave-heated reactors in parallel is a major technical challenge for scaling up this syngas-generating technology. In this work, we introduced a novel microwave heating-assisted cyclic simulated moving bed reactor to solve this technical challenge. We developed a model that incorporates bed hydrodynamics, mass transfer, and reaction kinetics. We integrated it with temperature distribution in the bed, to simulate the reactivity of methane and carbon dioxide with the loaded bed, and Maxwell's equation to capture distribution of electromagnetic waves throughout the system. We verified this model with simulation results from literature and validated it by experimental data collected in this study. Upon model verification and validation and designing the reactor, we simulated the proposed reactor for a plant with an inlet methane flowrate of 50 tonnes/day to optimize operating conditions and reactor design parameters. The simulation results indicated that at a bulk temperature of 800 °C, the optimized design of the proposed reactor can (i) achieve nearly complete (≥0.98) methane conversion by only four reactors and (ii) ensure a uniform distribution of electromagnetic waves with more than 97 % of microwave absorption by loaded oxygen carrier beds.