Proposal of a novel modular photo-thermo-reactor system for cascaded hydrogen production from methanol steam reforming

In the present work, a novel modular photo-thermo-reactor (MPTR) for high-efficient and low-cost hydrogen production from methanol steam reforming (MSR), benefitting from synergistic photo-thermo-catalysis (PTC) with Pt/CuO catalyst and thermo-catalysis (TC) with Cu/ZnO/Al₂O₃ catalyst in a cascade way using composite catalyst beds, is proposed. The theory–experiment-based multiphysics model covering the optical, flow, thermal and chemical sub-processes is established in order to optimally design the MPTR. The predicted design-point performance of MPTR indicates that the PTC reaction breaks the limitation of normal TC reaction, which leads to the currently highest overall solar-to-hydrogen efficiency up to 24.1%, with the corresponding annual hydrogen production of 1211 Nm³/m² in Xi'an, China. Moreover, a location-sensitive economic analysis model is built, considering not only the conventional factors, such as investment, stock and M&O costs, but also the location related factors, such as the solar resources and transportation cost. The results demonstrate that the levelized cost of hydrogen (LCOH) could be reduced as low as 3.82 $/kg if the location of the proposed MPTR system is appropriately chosen.