Development of a kinetic approach for the liquid phase dehydrogenation of perhydro benzyltoluene

• Kinetic approach considering hydrogen partial pressure and thermodynamic equilibrium. • Mass transport effects and catalyst utilization in perhydro benzyltoluene dehydrogenation. • Intrinsic and effective kinetic approach for perhydro benzyltoluene dehydrogenation. This publication examines the dependency of the liquid phase dehydrogenation of perhydro-benzyltoluene (H12-BT) on process parameters like temperature, pressure and LOHC concentration, to develop a kinetic approach for a commercial dehydrogenation catalyst. The investigations revealed that the commercial pellet catalyst is limited by pore diffusion. Therefore, the catalyst was milled to study the intrinsic reaction rate. The investigations were used to develop both an intrinsic and an effective kinetic approach to describe the dehydrogenation of H12-BT. The kinetic approach developed in this work describes for the first time the liquid phase dehydrogenation of H12-BT considering the dependency of the reaction rate on the hydrogen partial pressure, and the limitation due to thermodynamic equilibrium. Additionally, the influence of reactant and product concentration and the concentration of the main intermediate is considered in the developed kinetic approach. Based on both kinetic approaches, the utilization of the catalyst is calculated and found to be below 50% under technically relevant conditions. The study therefore demonstrates the significant potential to optimize the catalyst in the future, as currently only part of the expensive platinum is being used effectively. The developed kinetic approaches provide the basis for future modelling of a dehydrogenation reactor.