Cyclohexane Dehydrogenation in Solar-Driven Hydrogen Permeation Membrane Reactor for Efficient Solar Energy Conversion and Storage

Cyclohexane dehydrogenation in the solar-driven membrane reactor is a promising method of directly producing pure hydrogen and benzene from cyclohexane and storing low-grade solar energy as high-grade chemical energy. In this paper, partial pressure of gases, conversion rate of cyclohexane, and energy efficiency of the reactor are analyzed based on numerical simulation. The process of cyclohexane dehydrogenation under four temperatures (200°C, 250°C, 300°C, and 350°C) and four permeate pressures (0.050 MPa, 0.025 MPa, 0.010 MPa, and 0.001 MPa) were studied. A complete conversion rate (99.9%) of cyclohexane was obtained as the reaction equilibrium shifts forward with hydrogen separation. The first-law thermodynamic efficiency, solar-to-fuel efficiency, and exergy efficiency could reach as high as 94.69%, 46.93% and 93.08%, respectively. This study indicates that it is feasible to combine solar energy supply technology with cyclohexane dehydrogenation reaction integrated with membrane reactor.