Ethane Dehydrogenation in a Palladium-Ruthenium Foil Membrane Reactor with a Chromia–Alumina Catalyst

Abstract

Ethane dehydrogenation is of great importance in view of the fact that the demand in ethylene, which is one of the most needed organic compounds, constantly increases. The main regularities of ethane dehydrogenation in a palladium-ruthenium foil membrane reactor with the AOK-73-24 microspherical chromia–alumina catalyst were investigated. The application of a palladium foil of 100% hydrogen selectivity makes it possible to produce high-purity hydrogen (99.999%) along with ethylene. Demand in the high-purity hydrogen as an environmentally friendly energy carrier for transport and electricity generation is constantly increasing. The reaction is studied under atmospheric pressure in a temperature range of 823–923 K at feed space velocities of 300 and 1200 h−1. The results obtained are compared with those obtained under the same conditions in a conventional reactor. It is found that in a membrane reactor at 823–923 K the selectivity of С2Н4 formation is 93–96%, while the formation of products of side reactions, CH4 and carbon deposits, is insignificant. The experiments in a conventional reactor show a higher conversion of the feedstock into carbon deposits increasing with an increase in the ethane consumption up to 22% at a flow rate of 1200 h−1. In a membrane reactor, an increase in the yield of ethylene at T=823 K and a feedstock consumption of 1200 h–1 is 86% of that in a conventional reactor. Under these conditions, about 85% of the formed H2 is removed from the reaction mixture through the membrane.