Climate change has made clear the need to decarbonize the global energy matrix, and green hydrogen has emerged as a promising alternative fuel. In this framework, this work investigates the green hydrogen production by means of a two-stage thermochemical water-splitting reactor heated by both a parabolic dish receiver and a photovoltaic heater. A mathematical model is proposed to simulate reduction–oxidation process for the solar-powered reactor composed of a porous cerium oxide medium. Experimental and numerical thermal profiles show good agreement, with a high temperature in the reduction stage (>1100 K) and a lower temperature in the oxidation stage (860–715 K). Green hydrogen productions show maximum values close to 100 ppm and 2000 μmolH2O/gCeO2, for experimental and numerical tests, respectively. It is concluded that the photovoltaic heater is more relevant than the solar concentration heater, and that green hydrogen production could be improved by allowing longer residence times for the reduction–oxidation stages.

中文翻译：

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基于氧化铈还原-氧化循环的两级热化学分解水反应器的数值和实验研究


气候变化清楚地表明了全球能源矩阵脱碳的必要性，而绿色氢已成为一种有前途的替代燃料。在这个框架中，这项工作研究了通过由抛物面碟式接收器和光伏加热器加热的两级热化学水分解反应器生产绿色氢气。提出了一个数学模型来模拟由多孔氧化铈介质组成的太阳能反应器的还原-氧化过程。实验和数值热分布显示出良好的一致性，还原阶段的高温 （>1100 K） 和氧化阶段的低温 （860–715 K）。对于实验和数值测试，绿色氢气产量的最大值分别接近 100 ppm 和 2000 μmolH2O/gCeO2。得出的结论是，光伏加热器比太阳能聚光加热器更相关，并且可以通过延长还原氧化阶段的停留时间来改善绿色氢气的生产。