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 d ense membrane tube was fabricated using aplastic extrusion technique. The o xygen permeances of the dense membrane tube were measured as functions of t emperature and oxygen partial pressure on the feed side. In the temperature range of 688-955 degrees C, the oxygen flux showed an approximately expone ntial dependence on temperature. The oxygen flux increased proportionally t o 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 th is material has fairly good catalytic activity for the OCM reaction. The ma ximum yield to C-2 hydrocarbons that was obtained was 16%, which compares f avorably to prior dense membrane studies. (C) 2000 Elsevier Science B.V. Al l rights reserved.