Methods for oxidative coupling of methane using metal oxide catalysts and a sulfur oxidant.

Process for dehydrogenation of alkanesor alkylbenzenes by using metal sulfide catalyst under the presence of small amounts of hydrogen sulfide.

Systems and methods include providing a gaseous alkane input stream and metal sulfide (MSx) particles that can react with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx-1) particle, and at least one of: hydrogen sulfide (H2S) and at least one sulfur containing compound selected from: S2, CS, and CS2. A product stream can be collected that includes the alkene and at least one of: hydrogen sulfide (H2S) and the at least one sulfur containing compound. A reduced metal sulfide (MSx-1) particle reacts with sulfur in a sulfur stream and can generate the metal sulfide (MSx) particle and hydrogen (H2).

The invention describes a process for the photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation employing a photocatalyst of microporous crystalline metal sulfide type, said process being carried out by bringing a charge containing the CO.sub.2 and at least one sacrificial compound into contact with said photocatalyst, then by irradiating the photocatalyst by at least one irradiation source producing at least one wavelength lower than the bandgap width of said photocatalyst, so as to reduce the CO.sub.2 and to oxidize the sacrificial compound, so as to produce an effluent containing, at least in part, C.sub.1 or more carbon-based molecules other than CO.sub.2.

Systems and methods include providing a gaseous alkane input stream and metal sulfide (MSx) particles that can react with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx−1) particle, and at least one of: hydrogen sulfide (H2S) and at least one sulfur containing compound selected from: S2, CS, and CS2. A product stream can be collected that includes the alkene and at least one of: hydrogen sulfide (H2S) and the at least one sulfur containing compound. A reduced metal sulfide (MSx−1) particle reacts with sulfur in a sulfur stream and can generate the metal sulfide (MSx) particle and hydrogen (H2).

Systems and methods include providing a gaseous alkane input stream and metal sulfide (MSx) particles that can react with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx-1) particle, and at least one of: hydrogen sulfide (H2S) and at least one sulfur containing compound selected from: S2, CS, and CS2. A product stream can be collected that includes the alkene and at least one of: hydrogen sulfide (H2S) and the at least one sulfur containing compound. A reduced metal sulfide (MSx-1) particle reacts with sulfur in a sulfur stream and can generate the metal sulfide (MSx) particle and hydrogen (H2).

The invention describes a process for the photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation employing a photocatalyst of microporous crystalline metal sulfide type, said process being carried out by bringing a charge containing the CO.sub.2 and at least one sacrificial compound into contact with said photocatalyst, then by irradiating the photocatalyst by at least one irradiation source producing at least one wavelength lower than the bandgap width of said photocatalyst, so as to reduce the CO.sub.2 and to oxidize the sacrificial compound, so as to produce an effluent containing, at least in part, C.sub.1 or more carbon-based molecules other than CO.sub.2.

Systems and methods include providing a gaseous alkane input stream and metal sulfide (MSx) particles that can react with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx-1) particle, and at least one of: hydrogen sulfide (H2S) and at least one sulfur containing compound selected from: S2, CS, and CS2. A product stream can be collected that includes the alkene and at least one of: hydrogen sulfide (H2S) and the at least one sulfur containing compound. A reduced metal sulfide (MSx-1) particle reacts with sulfur in a sulfur stream and can generate the metal sulfide (MSx) particle and hydrogen (H2).

A catalyst for the dehydrogenation of alkanes to alkenes comprises a catalytically active material supported on a carrier, wherein the catalytically active material is a metallic sulfide (MeS) comprising Fe, Co, Ni, Cu, Mo or W or any combination of two or more metals selected from Pb, Sn, Zn, Fe, Co, Ni, Cu, Mo and W. The catalyst is regenerated in several steps. The dehydrogenation is carried out at a temperature between 450 and 650 C. and a pressure from 0.9 bar below ambient pressure to 5 bar above ambient pressure.

Methods, catalysts, and systems for the production of 1,3-butadiene from a reaction mixture including ethylene and gaseous sulfur are described.