Enhancing the Oxygen Permeability of BaCo0.7Fe0.2Nb0.1O3-δ Membranes by Coating GdBaCo2-xFexO5+δ for Partial Oxidation of Coke Oven Gas to Syngas

The dense ceramic membranes BaCo0.7Fe0.2Nb0.1O3-delta (BCFN) combined with GdBaCo2-xFexO5+delta (0 <= x <= 2.0) surface modification layers was investigated for hydrogen production by partial oxidation reforming of coke oven gas (COG). As oxygen permeation of BCFN membrane is controlled by the rate surface exchange kinetics, the GdBaCo2-xFexO5+delta materials improve the oxygen permeation flux of the BCFN membrane by 20-44% under helium atmosphere at 750 degrees C. The maximum oxygen permeation flux reached 14.4 mL min(-1) cm(-2) in the GdBaCoFeO5+delta coated BCFN membrane reactor at 850 degrees C, and a CH4 conversion of 94.9%, a H-2 selectivity of 88.9%, and a CO selectivity of 99.6% have been achieved. The GdBaCo2-xFexO5+delta coating materials possess uniform porous structure, fast oxygen desorption rate and good compatibility with the membrane, which showed a potential application for the surface modification of the membrane reactor.