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.

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.

An integrated microchannel reactor and heat exchanger comprising: (a) a waveform sandwiched between opposing shim sheets and mounted to the shim sheets to form a series of microchannels, where each microchannel includes a pair of substantially straight side walls, and a top wall formed by at least one of the opposing shim sheets, and (b) a first set of microchannels in thermal communication with the waveform, where the waveform has an aspect ratio greater than two.

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 fuel producing system includes an electrolyzer that is supplied with a raw material gas containing carbon dioxide and water vapor, and electrolyzes the raw material gas to generate a product gas containing hydrogen and carbon monoxide, and a first gas-liquid separator that performs gas-liquid separation on the product gas generated in the electrolyzer. Water vapor produced from water separated in the first gas-liquid separator or water vapor produced from water from a water supply source is allowed to be supplied to the electrolyzer in addition to the raw material gas.

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 process for preparing C2 to C3 hydrocarbons may include introducing a feed stream including hydrogen gas and a carbon-containing gas comprising carbon monoxide, carbon dioxide, and mixtures thereof into a reaction zone of a reactor, and converting the feed stream into a product stream comprising C2 to C3 hydrocarbons in the reaction zone in the presence of a hybrid catalyst. The hybrid catalyst may include a metal oxide catalyst component and a microporous catalyst component comprising 8-MR pore openings less than or equal to 5.1 A and a cage defining ring size less than or equal to 7.45 A, where a C2/C3 carbon molar ratio of the product stream is greater than or equal to 0.7.

A process for preparing C2 to C3 hydrocarbons may include introducing a feed stream including hydrogen gas and a carbon-containing gas comprising carbon monoxide, carbon dioxide, and mixtures thereof into a reaction zone of a reactor, and converting the feed stream into a product stream comprising C2 to C3 hydrocarbons in the reaction zone in the presence of a hybrid catalyst. The hybrid catalyst may include a metal oxide catalyst component and a microporous catalyst component comprising 8-MR pore openings less than or equal to 5.1 A and a cage defining ring size less than or equal to 7.45 A, where a C2/C3 carbon molar ratio of the product stream is greater than or equal to 0.7.