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

Abstract

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 CeO2 and Ni,Mn-ferrite (Ni0.5Mn0.5Fe2O4). It has a cylindrical rotor and dual cells for discharging O2 and for the H2O 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 CeO2 was achieved, and successive evolution of H2 was observed in the H2O-splitting reaction cell at the optimum reaction temperatures of the O2-releasing reaction cell (T = 1623 K) and H2O-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 O2-releasing and H2-generation reactions were 1473 and 1173 K, respectively. It was confirmed that the higher O2-releasing reaction temperature of above 1800 K was achieved with the about 10-times scaled-up rotary-type solar reactor.

A review of solar methane reforming systems

“…A slightly different rotary reactor has also been proposed for solar hydrogen production through a two step water splitting process [106]. A schematic of this reactor is shown in Figure 36.…”

“…The thermal energy required for the water splitting reaction was obtained from the the solar energy absorbed during the reduction process. In this reactor, CeO 2 and Ni,Mn-ferrite were used as the reactive ceramics with hydrogen production observed at a reactor temperature of 1273 K and 1173 K, respectively [106].…”

“…A chemical looping reformer allows for more flexibility in design as a Figure 36: Schematic of solar rotary reactor for water splitting [106] number of different metal oxides can be used (discussed previously in Section 3.5). Moreover, a noble metal catalyst is not necessary.…”

A-site substitution effect of perovskite-type cobalt and manganese oxides on two-step water splitting reaction for solar hydrogen production

“…A solar reactor is being developed for the two-step water splitting process with ceria-based reactive ceramics and concentrated solar heat to produce solar hydrogen. The ceria (CeO 2 )-based reactive ceramics is reduced in the O 2 -releasing reaction around 1400 ºC on the reactor, and reduced ceramics is oxidized with steam in the following H 2 -generation reaction [1]. Variety of solar thermochemical processes with concentrated solar heat are employed to split H 2 O for hydrogen production [2,3].…”

Finite element method simulations of heat flow in fixed bed solar water splitting redox reactors

“…These cycles offer the simplest process as they can be used in a fixed bed reactor. Many promising materials have been identified including supported NiFe 2 O 4 and CeO 2 [9,10,11,12]. Both of these compounds are partially reduced releasing some of their oxygen.…”