A novel solar chemical reactor has been designed to perform the combined ZnO-reduction and CH4-reforming processes. It consists of a gas-particle vortex flow confined to a solar cavity-receiver that is exposed to concentrated solar irradiation. A 5-kW reactor was fabricated and tested in a high-flux solar furnace. The design methodology and experimental program are described. Tests were conducted from 1000 to 1600 K and yielded up to 90% chemical conversion of zinc in a single pass.