Methane coupling by membrane reactor. Quarterly technical progress report, September 25--December 24, 1996

A new catalyst, 1.9%(wt) Mn-5%(wt) Na{sub 2}WO{sub 4}/SiO{sub 2} was synthesized by the incipient wetness impregnation method. X-ray diffraction studies of the catalyst calcined at 800 C showed that cristobalite, Na{sub 2}WO{sub 4}, and Mn{sub 2}O{sub 3} were the three phases that coexisted in the catalyst. Calcination at 1,000 C resulted in the formation of a new SiO{sub 2} phase (tridymite). The new catalyst was characterized by running the methane oxidative coupling reactions in a conventional packed bed reactor. The highest C{sub 2} yield obtained was 25%. The Mn-W-Na/SiO{sub 2} catalyst was coated on the inside wall of the SrFeCo{sub 0.5}O{sub 3{minus}x} dense membrane tube. A methane oxidative coupling experiment was conducted with the new catalyst in a dense membrane reactor. The oxygen permeance of the dense membrane tube coated with the catalyst was about 0.05 cc/min/cm{sup 2} at 850 C. By co-feeding methane and oxygen to the tube side of the reactor, C{sub 2} yields up to 7% were observed in these runs. To prepare the membrane tube for the radial flow reactor, silica was deposited on a lanthanum stabilized gamma alumina membrane tube and gas permeances were measured after the membrane tube was calcined at different temperatures. The pressure drop across the membrane was high enough for the membrane to be used in the radial flow reactor