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Transport Mechanism of Steam Methane Reforming on Fixed Bed Catalyst Heated by High Temperature Helium for Hydrogen Production: A Computational Fluid Dynamics Investigation

In this study, we numerically evaluated the performance of a steam methane reforming (SMR) reactor heated using high-temperature helium for hydrogen production. The result showed that with an increase in the reactant gas inlet velocity, the temperature at the same reactor length position decreased. The maximum gas temperature difference at the gas collection chamber reached approximately 55 °C. The outlet temperature difference increased to 35 °C when the inlet temperature increased from 370 °C to 570 °C. A higher inlet temperature did not have a positive effect on the system's thermal efficiency. The methane conversion rate increased by 68%, and the hydrogen production rate increased by 55%, when the helium inlet velocity increased from 2 m/s to 22 m/s. When the helium inlet temperature increased by 200 °C, the highest temperature of the reactant gas increased by 132 °C. In the SMR for hydrogen production using a high-temperature gas-cooled reactor (HTGR), low reactant-gas inlet velocity, suitable inlet temperature, high inlet velocity, and a high HTGR outlet temperature of helium were preferable.