Continuous dehydrogenation of perhydro benzyltoluene in a three-phase stirred tank slurry reactor

Liquid organic hydrogen carriers (LOHCs) offer a promising solution for the safe and scalable storage and
transportation of hydrogen. While efficient hydrogenation is less of a challenge, technical dehydrogenation poses
multifold hurdles due to its endothermic nature, slow kinetics, and highly dynamic three-phase conditions. This
study presents use of a continuous three-phase stirred tank slurry reactor for the dehydrogenation of the LOHC
perhydro benzyltoluene as an alternative to conventional fixed-bed reactor concepts. The slurry reactor was
evaluated systematically by variation of stirrer speed, feed rate, and operation temperature to identify operating
regimes enabling stable and controlled hydrogen release under continuous three-phase conditions. Long-term
operation under technically relevant temperature and pressure levels demonstrated stable operation with effi-
cient phase separation, sustained catalyst activity, and minimal LOHC degradation. At 310 ◦C, a stable Pt-based
hydrogen productivity of 2.7 gH2 gPt
1 min 1 and a degree of dehydrogenation of approx. 40% were obtained,
which indicates efficient catalyst utilisation when compared to other reported reactor concepts. ... mehrRestart exper-
iments showed that mechanical agitation effectively restores performance after shutdown. However, repeated
rapid on-off cycles led to temporary deviations from steady-state. In addition, continuous hydrogenation was
demonstrated using a catalyst basket configuration, achieving a degree of hydrogenation of 99.9% and con-
firming the general suitability of the continuous stirred tank reactor (CSTR) configuration for reversible LOHC
operation. Overall, the study positions the three-phase slurry CSTR as a complementary reactor concept
emphasising catalyst efficiency, thermal homogeneity, and operational stability under continuous operation.