Steam Reforming of Ethane in a Membrane Reactor with a Nickel Catalyst at High Temperatures

A model of steam reforming of pure ethane in a membrane catalytic reactor is proposed. The working elements of the reactor are cylindrical chambers, between which a hydrogen-selective palladium foil is placed. The upper chamber is vacuumized, and the lower one contains a nickel catalyst. In the case of uniform feed of the feedstock (С2Н6 and Н2О) along the perimeter of the lower chamber, the problem is reduced to finding the average flows of С2Н6, СН4, Н2О, СО, СО2, and Н2 by solving a system of nonlinear ordinary differential equations. The studies are carried out in the temperature range of 700–1000 K at acceptable steam/ethane input flow ratios of more than four. The optimal conditions for the process, at which the hydrogen yield is 100%, are found. It is proved that under these conditions and a fixed temperature, the maximum hydrogen flow through the membrane is observed at the minimum permissible ratio of the steam and ethane input flows, equal to four. Comparison of the calculations with the experimental data confirm the assumption of the existence of two sections in the lower chamber (short initial and main sections).