Direct conversion of syngas to light olefins is carried out in a fixed bed or a moving bed reactor with a composite catalyst A+B. The active ingredient of catalyst A is active metal oxide; and catalyst B is one or more than one of zeolite of CHA and AEI structures or metal modified CHA and/or AEI zeolite. A spacing between geometric centers of the active metal oxide of the catalyst A and the particle of the catalyst B is 5 m-40 mm. A spacing between axes of the particles is preferably 100 m-5 mm, and more preferably 200 m-4 mm. A weight ratio of the active ingredients in the catalyst A and the catalyst B is within a range of 0.1-20 times, and preferably 0.3-5.

Integrated systems are provided for the production of higher hydrocarbon compositions, for example liquid hydrocarbon compositions, from methane using an oxidative coupling of methane system to convert methane to ethylene, followed by conversion of ethylene to selectable higher hydrocarbon products. Integrated systems and processes are provided that process methane through to these higher hydrocarbon products.

The present disclosure provides oxidative coupling of methane (OCM) systems for small scale and world scale production of olefins. An OCM system may comprise an OCM subsystem that generates a product stream comprising C.sub.2+ compounds and non-C.sub.2+ impurities from methane and an oxidizing agent. At least one separations subsystem downstream of, and fluidically coupled to, the OCM subsystem can be used to separate the non-C.sub.2+ impurities from the C.sub.2+ compounds. A methanation subsystem downstream and fluidically coupled to the OCM subsystem can be used to react H.sub.2 with CO and/or CO.sub.2 in the non-C.sub.2+ impurities to generate methane, which can be recycled to the OCM subsystem. The OCM system can be integrated in a non-OCM system, such as a natural gas liquids system or an existing ethylene cracker.

A catalyst for catalytic reactors of which the outer shape is a helix with n blades, where n is greater than or equal to 1, wherein the stack void fraction percentage is between 75% and 85% and the surface area/volume ratio is greater than 1000 square meters/square meters.

A catalyst for catalytic reactors of which the outer shape is a helix with n blades, where n is greater than or equal to 1, wherein the stack void fraction percentage is between 75% and 85% and the surface area/volume ratio is greater than 1000 square meters/square meters.

The invention relates to a catalyst, comprising a catalytic element disposed on a substrate, wherein said substrate has formula Ce.sub.1-xM.sub.xO.sub.2, wherein x is between about 0 and about 0.3, optionally between about 0.01 and about 0.3, and wherein M, if present, is a metallic element other than Ce, when used for catalysing a methanation reaction. There is also described use of the catalyst for catalysing a methanation reaction and a method for methanation of a feedstock including carbon monoxide and hydrogen, said method comprising contacting the feedstock with the catalyst.

Provided is a process for producing hydrogen gas in a separate stream from syngas. An assembly for producing hydrogen gas in a separate stream from syngas and a method of producing hydrogen are also provided.

The present disclosure provides oxidative coupling of methane (OCM) systems for small scale and world scale production of olefins. An OCM system may comprise an OCM subsystem that generates a product stream comprising C.sub.2+ compounds and non-C.sub.2+ impurities from methane and an oxidizing agent. At least one separations subsystem downstream of, and fluidically coupled to, the OCM subsystem can be used to separate the non-C.sub.2+ impurities from the C.sub.2+ compounds. A methanation subsystem downstream and fluidically coupled to the OCM subsystem can be used to react H.sub.2 with CO and/or CO.sub.2 in the non-C.sub.2+ impurities to generate methane, which can be recycled to the OCM subsystem. The OCM system can be integrated in a non-OCM system, such as a natural gas liquids system or an existing ethylene cracker.

This disclosure relates to the production of xylenes from syngas, in which the syngas is converted to an aromatic product by reaction with an isosynthesis catalyst and an aromatization catalyst. The isosynthesis catalyst and aromatization catalyst may be different catalysts or combined into a single catalyst. The aromatic product is then subjected to one of more of (i) xylene isomerization, (ii) transalkylation with at least one C.sub.9+ aromatic hydrocarbon, and (iii) alkylation with methanol and/or carbon monoxide and hydrogen to increase its p-xylene content.

This disclosure relates to the production of xylenes from syngas, in which the syngas is converted to an aromatic product by reaction with an isosynthesis catalyst and an aromatization catalyst. The isosynthesis catalyst and aromatization catalyst may be different catalysts or combined into a single catalyst. The aromatic product is then subjected to one of more of (i) xylene isomerization, (ii) transalkylation with at least one C.sub.9+ aromatic hydrocarbon, and (iii) alkylation with methanol and/or carbon monoxide and hydrogen to increase its p-xylene content.