Mathematical modeling for investigating the effect of modes of operation on performance of dehydrogenation of ethylbenzene in the palladium membrane reactor

Abstract

The dehydrogenation of ethylbenzene to styrene in palladium membrane reactor was studied. The study was divided into 3 main parts: the performance of fixed-bed reactor and membrane reactor, comparison between different mathematical models and study on the membrane reactor. Mathematical models taking into account the non-isothermal condition and radial heat and mass dispersion were developed to investigate reactor performance at various operating conditions. Kinetic data of Fe2O3 and K2O catalyst and permeation data of gas hydrogen through a palladium membrane with 10 pm thickness were used in the modeling. The study showed that due to the continuous removal of hydrogen from the reaction zone, the conversion and the selectivity of the membrane reactor was superior to the conventional fixed-bed reactor. It was proved that the assumption of isothermal and plug flow condition overestimated the performance of the reactors. The membrane reactor with the catalyst packed in the shell side showed superior performance to the one with the catalyst packed in the tube side due to the superior heat transfer. It was also found that the operating modes in the separation side played an important role in determining the reactor performance. The use of reactive sweep gas supplied additional heat to the reaction zone; however, the resulting performance may be