Recent Developments in CFD Modeling of CO Preferential Oxidation in Microchannel Reactors

Hydrogen-rich reformate produced by hydrocarbon reforming contains residual carbon monoxide that must be reduced to trace levels before use in proton exchange membrane fuel cells. Preferential oxidation of carbon monoxide (CO-PROX) in microchannel reactors is a promising purification route because of its compactness, high surface-to-volume ratio, short diffusion distances, and enhanced heat-transfer capability. This review examines advances in computational fluid dynamics modeling of CO-PROX microreactors, focusing on catalyst type, reaction kinetics, channel geometry, washcoat properties, operating conditions, and thermal management. Studies involving noble-metal, transition-metal oxide, and bimetallic catalysts are compared in terms of CO conversion, selectivity, stability, and resistance to carbon dioxide and water vapor. The reviewed results show that reactor performance depends on the interaction among intrinsic kinetics, residence time, oxygen availability, heat removal, and mass-transfer resistance. Excess oxygen and elevated temperature may improve CO conversion but also intensify hydrogen oxidation and promote CO regeneration through the reverse water-gas shift reaction. Carbon dioxide generally causes stronger inhibition than water vapor, while thick washcoats and large channels increase transport limitations. Overall, CFD enables detailed analysis of local temperature, concentration, and reaction-rate fields and supports the design and optimization of compact, selective, and thermally stable CO-PROX systems for fuel-cell-grade hydrogen production.

کلیدواژه ها:

Hydrogen Purification ، CO Preferential Oxidation ، Microchannel Reactor ، CFD modeling