Sorbent materials that allow for high-temperature, regenerative desulfurization of fuel gas streams for the anode of a solid oxide fuel cell have been developed. Reversible adsorption of H2S on cerium and lanthanum oxide surfaces is demonstrated over many cycles at temperatures as high as 800 degrees C, on both fresh or presulfided sorbents, and at very high space velocities. The adsorption and desorption processes are very fast, and removal of H2S to sub-parts per million levels is achieved at very short (millisecond) contact times. Any type of sulfur-free gas, including water vapor, can be used to regenerate the sorbent surface. Preferably, the anode off-gas stream is used to sweep the desorbed H(2)S to a burner.

Non-oxidative methane conversion over Fe©SiO catalyst was studied for the first time in a hydrogen (H ) permeable tubular membrane reactor. The membrane reactor is composed of a mixed ionic-electronic SrCe Zr Eu O thin film (≈20 μm) supported on the outer surface of a one-end capped porous SrCe Zr O tube. Significant improvement in CH conversion was achieved upon H removal from the membrane reactor compared to that in a fixed-bed reactor. The Fe©SiO catalyst in the H permeable membrane reactor demonstrated a stable ≈30 % C single-pass yield, with up to 30 % CH conversion and 99 % selectivity to C (ethylene and acetylene) and aromatic (benzene and naphthalene) products, at the tested conditions. The selectivity towards C or aromatics was manipulated purposely by adding H into or removing H from the membrane reactor feed and permeate gas streams.

Earth Oxides. -La2O3 is used to reversibly and very efficiently adsorb H2S from reformate gas mixtures at 800°C to protect the anode of an solid oxide fuel cell. Similar results are obtained with CeO2 and Ce/70%LaOx. The adsorption and desorption processes are very fast, and removal of H2S to sub-ppm levels is achieved at very short (millisecond) contact times. Any type of sulfur-free gas, including H 2 O vapor, can be used to regenerate the sorbent surface. -(FLYTZANI-STEPHANOPOULOS*, M.; SAKBODIN, M.; WANG

Non-oxidative methane conversion over FeSiO 2 catalyst was studied for the first time in ah ydrogen (H 2 ) permeable tubular membrane reactor.T he membrane reactor is composed of am ixed ionic-electronic SrCe 0.7 Zr 0.2 Eu 0.1 O 3Àd thin film ( % 20 mm) supported on the outer surface of ao neend capped porous SrCe 0.8 Zr 0.2 O 3Àd tube.Significant improvement in CH 4 conversion was achieved upon H 2 removal from the membrane reactor compared to that in afixed-bed reactor. The FeSiO 2 catalyst in the H 2 permeable membrane reactor demonstrated astable % 30 %C 2+ single-pass yield, with up to 30 %CH 4 conversion and 99 %selectivity to C 2 (ethylene and acetylene) and aromatic (benzene and naphthalene) products, at the tested conditions.The selectivity towardsC 2 or aromatics was manipulated purposely by adding H 2 into or removing H 2 from the membrane reactor feed and permeate gas streams.

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