Design and optimization study on a novel active/inactive catalyst particle multi-zone mixing fixed packed bed for cost-efficient solar-driven hydrogen production

For more cost-efficient solar-driven hydrogen production in parabolic trough solar receiver-reactor systems, a novel active/inactive catalyst particle multi-zone mixing fixed packed bed is designed and optimized in this paper. Inspired by multi-physics mismatched coupling relationship revealed, the locally separately decoupling interfaces between active and inactive catalyst multi-zones were proposed to regulate the spatial thermal-chemical matching relationship. A three-dimensional isothermal surface fitting method was proposed to determine the multi-zone mixing interfaces. Corresponding novel multi-stages systems were further designed and optimized. The results show that the novel system can effectively improve the spatial thermal-chemical matching relationship by locally reusing inactive catalysts. The nearly optimal three-stages novel system saves 48.3% of the original active catalyst filling in a more cost-efficient yet safe way, which greatly improves the hydrogen production per unit mass of active catalyst by 82.26% under the sintering temperature limit. It provides a new regulating idea for similar solar-driven thermochemical applications.