Dehydrogenation of C 3–C 4 paraffins on Cr 2O 3/Al 2O 3 catalysts in fluidized and fixed bed reactors

Abstract

Thermodynamic calculations for dehydrogenation of a model C 3–C 4 paraffin mixture indicate that there is a complex mutual effect of the components on the equilibrium yield of olefins. Each component can act simultaneously: (i) as a diluent shifting the dehydrogenation equilibrium of the mixture components to the desired olefin and (ii) as an additional source of hydrogen to the reaction zone, which shifts the dehydrogenation equilibrium to the left. Experiments on dehydrogenation of model C 1–C 4 paraffin mixtures on Cr 2O 3/Al 2O 3 catalysts in fluidized and fixed beds show an increase of the total conversion of C 3–C 4 paraffins to olefins and an increase of the total process selectivity to olefins.