Direct solar-thermal scalable-decomposition of methanol flowing through a nanoparticle-packed bed reactor under outdoor environment

Using nanoparticles to absorb sunlight and drive methanol decomposition is a potential approach of solar energy utilization, which can convert solar energy into chemical energy of syngas. But a challenge of nanoparticle solar methanol decomposition is how to design concise and efficient large-scale application method. Focusing on the key issues of energy conversion and reaction system optimization, this work analyzes the sunlight capture, flow heat transfer and catalytic reaction in the nanoparticle volumetric absorption solar methanol decomposition system by theoretical and experimental studies. And the applied scalable solar-chemical system is constructed. The results show that the reaction bed constructed by nanoparticles has advanced solar energy capture performance, and can effectively drive the methanol decomposition. Compared with the traditional system, it has the lower solar concentration ratio of 17.5 and the higher energy conversion efficiency of 35.5%, and the reaction can be started up at the temperature of 136 °C. The cumulative solar-to-fuel energy conversion in this work can reach 1.3 × 10¹¹ J/m² in one year of operation in Nanjing, China. This work can further guide the construction of solar-driven thermochemical systems of splitting methanol into syngas and storing solar energy.