Thermochemical H2O and CO2 splitting redox cycles in a NiFe2O4 structured redox reactor: Design, development and experiments in a high flux solar simulator

A high flux solar simulator allows the lab-scale assessment of solar reactor concepts by irradiating a target with high flux thermal energy, similarly to reactors installed in concentrated solar radiation facilities such as central towers with a heliostat field. In the current study, the design and construction of a high flux solar simulator facility for near realistic solar experiments is presented. A simple, cavity-tubular thermochemical reactor is employed for the evaluation of the redox activity of structured monolithic bodies (foams and honeycombs) consisting entirely of NiFe₂O₄ w.r.t·H₂O splitting, CO₂ splitting and combined H₂O-CO₂ splitting reactions. Experiments under realistic conditions, i.e. a solar reactor under irradiation, were conducted to assess the solar fuels production capability, which was examined at the structure level and the reactor level. The best performing structure was the NiFe₂O₄ foam. Further multilevel research (structure, reactor as well as redox material), will improve product yield and reactor efficiency.