Oxygen-permeable dense membrane reactor for the oxidative coupling of methane

A perovskite material (BaCe0.8Gd0.2O3) in powder form, with both electronic and ionic conductivity, was synthesized by the ethylene glycol method. A dense membrane tube was fabricated using aplastic extrusion technique. The oxygen permeances of the dense membrane tube were measured as functions of temperature and oxygen partial pressure on the feed side. In the temperature range of 688-955 degrees C, the oxygen flux showed an approximately exponential dependence on temperature. The oxygen flux increased proportionally to the natural logarithm of the ratio of oxygen partial pressures across the membrane. Experimental results for the oxidative coupling of methane (OCM) to C-2 hydrocarbons, in the absence of additional catalyst, showed that this material has fairly good catalytic activity for the OCM reaction. The maximum yield to C-2 hydrocarbons that was obtained was 16%, which compares favorably to prior dense membrane studies. (C) 2000 Elsevier Science B.V. All rights reserved.