Particle fluidized bed receiver/reactor with a beam-down solar concentrating optics: Performance test of two-step water splitting with ceria particles using 30-kWth sun-simulator

The first performance test of a novel windowed solar fluidized bed reactor was carried out for a two-step water splitting cycle with ceria particles by using a 30-kWth sun-simulator. O2 and H2 were successfully produced by the reactor system. During the thermal reduction step of the two-step water splitting, a fluidized bed of ceria particles was created by passing N2 gas through the perforated bottom plate of the reactor, and about 30 kWth of high flux visible light from 19 xenon-arc lamps of the sun-simulator was directed inside the reactor through a quartz window to directly irradiate the top of the fluidized bed. The central bed temperature reached the temperature of 1400 to 1500°C in the thermal reduction step. The subsequent water decomposition or hydrolysis step was performed at the central bed temperature of 800 - 900°C. About 6 - 12 Ndm3 of hydrogen was produced by one cycle.