Multiscale reaction and heat transfer investigation of methylcyclohexane dehydrogenation: A CFD study

Abstract

As one of liquid organic hydrogen carriers, the methylcyclohexane‐toluene (MCH‐TOL) system has been widely investigated with fixed bed reactor. However, the dehydrogenation process is restricted by a highly endothermic reaction and the heat transfer drawback of the fixed bed reactor, followed by waste of catalyst, requiring optimization to homogenize temperature and promote dehydrogenation performance. This study investigated the influence of reactor geometry and operating parameters on the dehydrogenation performance of the MCH‐TOL system from the computational fluid dynamics perspective. At the reactor scale, the effect of multiple operation conditions on heat transfer is analyzed with the temperature‐reaction‐rate outline; at the particle scale, catalyst dilution and turbulence are simulated to reduce heat resistance in solid and fluid phases. Finally, an improved reactor design is proposed by reducing tube diameter and catalyst dilution, which achieves 95% heat uniformity and almost optimal MCH conversion from 613 to 723 K, thereby providing the process scheme that fully exploits catalyst activity.