Development Study on Solar Hydrogen Production with Concentrated-Solar-Beam Reactive Ceramics

在研制镍铁氧体（反应陶瓷）太阳能释氧反应器中，通过在1473- 1773 K温度范围内反复进行两步水分解，成功地实现了水分解反应的连续进行。针对锌铁氧体体系，基于回收ZnO+ Fe_3 O_4粉末混合物的概念，设计了一种新型的太阳能反应器，并制作了实用的高温热测试仪，以提高锌铁氧体体系的反应活性。发现采用锌铁氧体系统的太阳能反应器可用于进行O2-在1573 K左右释放。此外，圆柱形旋转反应器是新设计和制造的，其中O2释放和H2生成步骤可以使用红外成像炉连续重复。通过对塔式太阳能聚光装置的光学系统的设计，发现在高太阳角下可以获得3000 °的聚光度，即使聚光度至少需要2700 °，当吸热反应进行时，对于2000 kW/m2的束流，YSZ 01 NF的消耗为6.22mol/m2，表明对于双型太阳能反应器（圆柱形旋转反应器），固体反应床的厚度为几cm。因此，结合新开发的反应陶瓷YSZ 01 NF和双型太阳能反应器，通过太阳能/化学能转换，可以最大限度地利用高太阳能束流来实现太阳能制氢。

In the development of solar reactor for O2-releasing with Ni-ferrite (reactive ceramics), the two-step water splitting can be successfully proceeded repeatedly by temperature swing between 1473-1773K. For the Zn-ferrite system, a new solar reactor is designed based on the concept of recovering the powder mixture of ZnO+Fe3O4, and fabricated the practical testing instrument with a high temperature heat, for enhancing the reactivity of the Zn-ferrite system.With this experiment, it was found that the solar reactor adopting the Zn-ferrite system can be developed for proceeding the O2-releasing process at the temperature around 1573K. Also, the cylindrical rotary reactor was newly designed and fabricated, with which the O2-releasing and H2-generation steps can be continuously repeated using infra red imaging furnace. It was confirmed that the cylindrical rotary reactor can work with a high efficiency for the two step water splitting process.The optical system of the tower solar concentration plant was designed, and it was found that 3000 concentration can be obtained at the high solar angle, even though 2700 concentration is at least required, for the practical requirement of 2000 solar concentration.When the endothermic reaction proceeds, 6.22mol/m2 of YSZ01NF is consumed for 2000kW/m2 of the beam flux, indicating that the thickness of the solid reaction bed is several cm for the dual type solar reactor (cylindrical rotary reactor). Thus, combining the newly developed reactive ceramics of YSZ01 NF and the dual type solar reactor, the solar hydrogen production can be realized by making the best use of a high solar beam flux through the solar/chemical energy conversion.