High-temperature slurry-phase dehydrogenation of perhydro-benzyltoluene – boosting catalyst productivity by optimized heat transfer

Liquid organic hydrogen carrier, like perhydro benzyltoluene (H12-BT), offer a promising solution for the safe storage and transport of hydrogen using the existing fuel infrastructure. So far, the sluggish endothermal hydrogen release through catalytic dehydrogenation has been considered as the main drawback of this otherwise very attractive concept. This study reports on the Pt-catalyzed dehydrogenation of H12-BT using a commercial catalyst (EleMax-D102 of Clariant) in powdered form in a batch-mode slurry phase reactor at elevated temperatures between 300 and 360 °C. Surprisingly, the high-temperature operation in this specific setup resulted in a dramatic increase of hydrogen release productivity compared to all available reports using classical fixed-bed reactors with the same catalyst in pellet form or at lower temperatures. For H12-BT dehydrogenation at 360 °C, we demonstrate record-high release productivities of up to 180 g H2 g Pt −1 min −1 (at low to moderate degree of dehydrogenation) corresponding to a catalyst mass-specific power provision of 360 kW g Pt −1 (based on the lower heating value of the released H 2 ). Interestingly, despite these harsh high performance-conditions, the formation of undesired by-products, including methyl fluorene or CO remains very low. Our results show that the role of mass and heat transfer limitations in H12-BT dehydrogenation has been largely underestimated to date.