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 methods and systems for producing an olefin, such as ethylene and propylene. A method for producing an olefin can comprise injecting an oxidizing agent and methane into an oxidative coupling of methane (OCM) reactor to generate ethylene. The methane and/or additional feedstocks for the OCM reactor can be derived from a thermal cracking or fluidized catalytic cracking (FCC) process. The ethylene generated in the OCM reactor can be converted to propylene through a dimerization unit and metathesis unit.

The present disclosure provides methods and systems for producing an olefin, such as ethylene and propylene. A method for producing an olefin can comprise injecting an oxidizing agent and methane into an oxidative coupling of methane (OCM) reactor to generate ethylene. The methane and/or additional feedstocks for the OCM reactor can be derived from a thermal cracking or fluidized catalytic cracking (FCC) process. The ethylene generated in the OCM reactor can be converted to propylene through a dimerization unit and metathesis unit.

The present disclosure provides methods and systems for producing an olefin, such as ethylene and propylene. A method for producing an olefin can comprise injecting an oxidizing agent and methane into an oxidative coupling of methane (OCM) reactor to generate ethylene. The methane and/or additional feedstocks for the OCM reactor can be derived from a thermal cracking or fluidized catalytic cracking (FCC) process. The ethylene generated in the OCM reactor can be converted to propylene through a dimerization unit and metathesis unit.

An olefin and methanol co-production plant for co-production of an olefin and methanol from a source gas containing methane includes: an olefin production unit for producing the olefin; and a methanol production unit for producing methanol from a carbon oxide gas in the olefin production unit. The olefin production unit includes a partial oxidative coupling device for producing the olefin by partial oxidative coupling reaction of methane contained in the source gas. The methanol production unit includes a reforming device for producing hydrogen by reforming reaction of methane, and a methanol production device for producing methanol by reaction with hydrogen produced by the reforming device. At least one of the reforming device or the methanol production device is configured to perform reaction using the carbon oxide gas in the olefin production unit.

An olefin and methanol co-production plant for co-production of an olefin and methanol from a source gas containing methane includes: an olefin production unit for producing the olefin; and a methanol production unit for producing methanol from a carbon oxide gas in the olefin production unit. The olefin production unit includes a partial oxidative coupling device for producing the olefin by partial oxidative coupling reaction of methane contained in the source gas. The methanol production unit includes a reforming device for producing hydrogen by reforming reaction of methane, and a methanol production device for producing methanol by reaction with hydrogen produced by the reforming device. At least one of the reforming device or the methanol production device is configured to perform reaction using the carbon oxide gas in the olefin production unit.

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.

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.

Described are methods for converting methane to olefins, aromatics, or a combination thereof using a single atom catalyst comprising CeO.sub.2 nanoparticles impregnated with individual atoms of noble metals including Pt, Pd, Rh, Ru, Ag, Au, Ir, or a combination thereof. These single atom catalysts of the present invention are heated with methane to form olefins and aromatics.

Described are methods for converting methane to olefins, aromatics, or a combination thereof using a single atom catalyst comprising CeO.sub.2 nanoparticles impregnated with individual atoms of noble metals including Pt, Pd, Rh, Ru, Ag, Au, Ir, or a combination thereof. These single atom catalysts of the present invention are heated with methane to form olefins and aromatics.