CFD simulation on hydrogen-membrane reactor integrating cyclohexane dehydrogenation and CO2 methanation reactions: A conceptual study.

[Display omitted] • Membrane reactor coupling dehydrogenation and methanation reactions is feasible. • High hydrogen permeance is prerequisite to positive effect of methanation reaction. • Enhancing methanation catalyst activity is not so beneficial limited by diffusion. • Increasing pressure is not promotional due to unfavorable thermodynamics. In this work, a novel hydrogen-membrane reactor coupling cyclohexane (CLH) dehydrogenation and CO 2 methanation was proposed. A 2D model was built up and the effects of hydrogen permeance, methanation rate and reaction pressure were examined with CFD simulation. It turned out that high hydrogen permeance was prerequisite to the positive effect of methanation reaction. And increasing hydrogen permeance of the membrane was able to promote both CLH and methanation reactions. While boosting methanation reaction could increase methane production yield at permeate side, but did not show much positive effect towards CLH conversion due to the limitation of radial diffusion of hydrogen molecules. Increasing pressure at retentate side even decreased CLH conversion slightly due to the negative thermodynamic effect. This work well proves the feasibility and advantage of the membrane reactor that integrates CLH dehydrogenation and CO 2 methanation reactions. [ABSTRACT FROM AUTHOR]