Modeling and operation analysis of solar-driven methane dry reforming over Ni/CeO2 in a kilowatt-scale solar thermochemical reactor

Solar thermochemical methane dry reforming converts CH4 and CO2 into high-value syngas by utilizing concentrated solar energy to drive endothermic reactions. The energy utilization efficiency of solar reactors is limited by improper operating conditions and excessive heat losses. In this work, a multi-physics numerical model of a kilowatt-scale solar cavity reactor packed with porous Ni/CeO2 catalyst was developed and validated against experimental data. The performances of methane dry reforming in the reactor including reactants conversion, reaction rates and energy efficiency under a typical experimental setup were evaluated. Furthermore, the effects of material input (CH4 mole fraction and reactants feeding rate), energy input (incident solar power), and porous catalyst parameters (porosity and equivalent diameter) on reactor thermochemical performance were systematically investigated. Under the designed operating conditions of 1.3 kW incident power, 8.0 L/min reactant flow rate, 0.40 CH4 mole fraction, and catalyst porosity and equivalent diameter of 0.86 and 1 mm, the solar-to-chemical, solar-to-thermal, and overall reactor efficiencies reached 34.05%, 64.96%, and 56.72%, respectively. This study opens up a new avenue for the large-scale utilization of solar energy.