Zeolite membrane reactor for isobutane dehydrogenation: Experimental results and theoretical modelling

Dehydrogenation of isobutane has been studied in a. packed-bed zeolite membrane reactor using Pt-In catalyst. Enhanced dehydrogenation yields were obtained in the membrane reactor due to the separation of hydrogen from the reaction medium. Two sweeping modes were studied, namely the co-current and the countercurrent modes. Although the separation factor is higher in countercurrent than in co-current, the yield bf reaction in these two sweeping modes is quite the same. The dehydrogenation reaction was limited by transport properties of the membrane in co-current mode while in countercurrent mode the limitation by kinetics was predominant. Reactor operation was described through theoretical modeling. A good agreement between the model and the experimental values was obtained with a co;current sweep gas. In countercurrent mode, the values predicted by the model for the yield of isobutene were slightly overestimated, due to hydrogen removal which induced catalyst local deactivation, or because the kinetic rate is inadequate when we are working far from the neighborhood of the equilibrium. (C) 1999 Elsevier Science Ltd. All rights reserved.