A catalyst for selectively oxidizing hydrogen sulfide to element sulfur, catalyst for burning tail-gas, and process for deeply catalytically oxidizing hydrogen sulfide to sulfur are disclosed. The catalyst for selectively oxidizing hydrogen sulfide to element sulfur is prepared by: 10-34% of iron trioxide and 60-84% of anatase titanium dioxide, and the balance being are auxiliary agents. Also a catalyst for burning tail-gas is prepared by: 48-78% of iron trioxide and 18-48% of anatase titanium dioxide, and the balance being auxiliary agents. The catalyst of the present invention has high selectivity and high sulfur recovery rate. An isothermal reactor and an adiabatic reactor of the present invention are connected in series and are filled with the above two catalysts for reactions, thus reducing total sulfur in the vented gas while having a high sulfur yield and conversion rate.

Catalysts for oxidative sulfur removal and methods of making and using thereof are described herein. The catalysts contain one or more reactive metal salts dispersed on one or more substrates. Suitable reactive metal salts include those salts containing multivariable metals having variable valence or oxidation states and having catalytic activity with sulfur compounds present in gaseous fuel streams. In some embodiments, the catalyst contains one or more compounds that function as an oxygen sponge under the reaction conditions for oxidative sulfur removal. The catalysts can be used to oxidatively remove sulfur-containing compounds from fuel streams, particularly gaseous fuel streams having high sulfur content. Due to the reduced catalyst cost, anticipated long catalyst life and reduced adsorbent consumption, the catalysts described herein are expected to provide a 20-60% reduction in annual desulfurization cost for biogas with sulfur contents ranges from 1000-5000 ppmv compared with the best adsorbent approach.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S-containing gas stream, particularly in the event that the stream also contains methane and/or ammonia. The catalyst comprises iron and molybdenum supported by a carrier comprising aluminum. The carrier preferably is alumina. The iron and molybdenum preferably are in the form of sulphides. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the preceding claims.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S-containing gas stream, particularly in the event that the stream also contains methane and/or ammonia. The catalyst comprises iron and molybdenum supported by a carrier comprising aluminium. The carrier preferably is alumina. The iron and molybdenum preferably are in the form of sulphides. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the preceding claims.

The various embodiments relate to a system and method for regenerating a direct oxidation catalyst that coverts H.sub.2S to elemental S. One embodiment of the method comprises regenerating a direct oxidation catalyst by contacting the direct oxidation catalyst with steam.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S-containing gas stream, particularly in the event that the stream also contains methane and/or ammonia. The catalyst comprises iron and molybdenum supported by a carrier comprising aluminum. The carrier preferably is alumina. The iron and molybdenum preferably are in the form of sulphides. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the preceding claims.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S-containing gas stream. The catalyst comprises at least one or more active metals selected from the group consisting of iron, cobalt, and nickel, supported by a carrier comprising ceria and alumina. The active metal is preferably in the form of its sulphide. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the composition claims.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S-containing gas stream. The catalyst comprises at least one or more active metals selected from the group consisting of iron, cobalt, and nickel, supported by a carrier comprising ceria and alumina. The active metal is preferably in the form of its sulphide. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the composition claims.