Design of a multi-inlet solar thermochemical reactor for steam methane reforming with improved performance

Reactor structure design plays an important role in the performance of solar-thermal methane reforming reactors. Based on a conventional preheating reactor, this study proposed a cylindrical solar methane reforming reactor with multiple inlets to vary the temperature field distribution, which improved the temperature of the reaction region in the reactor, thereby improving the reactor performance. A multi-physical model that considers mass, momentum, species, energy conservation, as well as thermochemical reaction kinetics of methane reforming, was applied to numerically investigate the reactor performance and analyze the factors that affect performance improvement. It was found that compared with a conventional preheating reactor, the proposed cylindrical reactor with inner and external inlets for gas feeding enhanced heat recovery from the exhausted gas and provided a more suitable temperature field for the reaction in the reactor. Under different operating conditions, the methane conversion in the cylindrical reactor with multi-inlet increased by 9.5% to 19.1%, and the hydrogen production was enhanced by 12.1% to 40.3% in comparison with the conventional design, even though the total reaction catalyst volume was reduced.