Modelling of a catalytic plate reactor for dehydrogenation–combustion coupling

Coupling an endothermic with an exothermic reaction in a plate heat exchanger having both sides of the plates covered with appropriate catalysts results in a compact and intensified unit known as catalytic plate reactor (CPR). In this work, catalytic ethane dehydrogenation taking place in a CPR having as heat source catalytic methane combustion is modelled. Reactor behaviour is studied utilising a two-dimensional model and the influence of parameters such as catalyst loading, flowrates and wall thermal conductivity is investigated. It is shown that the ratio of catalyst loadings for the two reactions is a key variable, which must be carefully adjusted in order to avoid hot spots or insufficient reactant conversion. It is further demonstrated that hot and cold spots develop when heat generated and heat consumed are not balanced locally. Utilisation of a metallic wall makes possible efficient heat transfer between endothermic/exothermic reaction locations for small temperature differences. However, lower plate thermal conductivity can lead not only to significant radial but also to axial temperature gradients.