Rotary-Type Solar Reactor for Solar Hydrogen Production with Two-step Water Splitting Process

The rotary-type solar reactor has been developed and fabricated for solar hydrogen production by a two-step water-splitting process using the reactive ceramics of CeO 2 and Ni,Mn-ferrite (Ni 0.5 Mn 0.5 Fe 2 O 4 ). It has a cylindrical rotor and dual cells for discharging O 2 and for the H 2 O splitting reaction. A detailed specification and the efficiency of the rotary-type solar reactor were examined for the two-step water-splitting process. The maximum temperature of the reactive ceramics mounted on the cylindrical rotor was ca. 1623 K by irradiation with a solar simulator of an infrared imaging lamp. Repetition of the two-step water-splitting process using the rotary-type solar reactor with CeO 2 was achieved, and successive evolution of H 2 was observed in the H 2 O-splitting reaction cell at the optimum reaction temperatures of the O 2 -releasing reaction cell ( T = 1623 K) and H 2 O-splitting reaction cell ( T = 1273 K). Also, repetition of the two-step water-splitting process was achieved in the case of using the reactive ceramics of Ni,Mn-ferrite, and its optimum reaction temperatures of the O 2 -releasing and H 2 -generation reactions were 1473 and 1173 K, respectively. It was confirmed that the higher O 2 -releasing reaction temperature of above 1800 K was achieved with the about 10-times scaled-up rotary-type solar reactor.