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.

Disclosed is a boiler may that uses recycled carbon dioxide as a working fluid. Instead of releasing high-purity CO.sub.2 into the atmosphere, the bulk of the CO.sub.2 is utilized as the working fluid and the produced CO.sub.2 is captured and sent to a pipeline for utilization or storage. These systems will minimize heat loss and achieve essentially zero CO.sub.2 emission to the air.

Disclosed are systems and processes to produce aromatic and olefinic compounds by aromatization and thermal cracking of hydrocarbons.

A system optionally including a carbon oxide reactor. A method for carbon oxide reactor control, optionally including selecting carbon oxide reactor aspects based on a desired output composition, running a carbon oxide reactor under controlled process conditions to produce a desired output composition, and/or altering the process conditions to alter the output composition.

A methanol synthesis plant comprising: a feed pretreating section operable to pretreat a feed stream; a synthesis gas (syngas) generation section comprising one or more reactors operable to produce a syngas synthesis product stream comprising synthesis gas from the feed stream; a methanol synthesis section comprising one or more methanol synthesis reactors operable to produce a synthesis product comprising methanol; and/or a methanol purification section operable to remove at least one component from the synthesis product to provide a purified methanol product; wherein the methanol synthesis plant is configured such that, relative to a conventional methanol synthesis plant, more of the net energy required by the methanol synthesis plant, the feed pretreating section, the syngas generation section, the methanol synthesis section, the methanol purification section, or a combination thereof, is provided by a non-carbon based energy source, a renewable energy source, and/or electricity.

The present disclosure provides a method for generating higher hydrocarbon(s) from a stream comprising compounds with two or more carbon atoms (C.sub.2+), comprising introducing methane and an oxidant (e.g., O.sub.2) into an oxidative coupling of methane (OCM) reactor that has been retrofitted into a system comprising an ethylene-to-liquids (ETL) reactor. The OCM reactor reacts the methane with the oxidant to generate a first product stream comprising the C.sub.2+ compounds. The first product stream can then be directed to a pressure swing adsorption (PSA) unit that recovers at least a portion of the C.sub.2+ compounds from the first product stream to yield a second product stream comprising the at least the portion of the C.sub.2+ compounds. The second product stream can then be directed to the ETL reactor. The higher hydrocarbon(s) can then be generated from the at least the portion of the C.sub.2+ compounds in the ETL reactor.

The present disclosure provides a method for generating higher hydrocarbon(s) from a stream comprising compounds with two or more carbon atoms (C.sub.2+), comprising introducing methane and an oxidant (e.g., O.sub.2) into an oxidative coupling of methane (OCM) reactor that has been retrofitted into a system comprising an ethylene-to-liquids (ETL) reactor. The OCM reactor reacts the methane with the oxidant to generate a first product stream comprising the C.sub.2+ compounds. The first product stream can then be directed to a pressure swing adsorption (PSA) unit that recovers at least a portion of the C.sub.2+ compounds from the first product stream to yield a second product stream comprising the at least the portion of the C.sub.2+ compounds. The second product stream can then be directed to the ETL reactor. The higher hydrocarbon(s) can then be generated from the at least the portion of the C.sub.2+ compounds in the ETL reactor.

A method for preparing ethylene, including: passing a feed stream containing C1 and C2 hydrocarbon compounds through a first heat exchanger and feeding the feed stream passed through the first heat exchanger to a second gas-liquid separator; feeding a part of a bottom discharge stream of the second gas-liquid separator to a demethanizer, passing an overhead discharge stream of the second gas-liquid separator through a second heat exchanger, feeding the overhead discharge stream of the second gas-liquid separator passed through the second heat exchanger to a third gas-liquid separator; feeding a bottom discharge stream of the third gas-liquid separator to the demethanizer; feeding a bottom discharge stream of the demethanizer to a C2 separator; feeding an overhead discharge stream of the C2 separator to a second compressor; passing a part of a compressed discharge stream of the second compressor through the first heat exchanger and feeding the part of the compressed discharge stream of the second compressor passed through the first heat exchanger to the second compressor as a first circulation flow; passing a part of the compressed discharge stream of the second compressor through the second heat exchanger and feeding the part of the compressed discharge stream of the second compressor passed through the second heat exchanger to a first compressor as a second circulation flow; and feeding a compressed discharge stream of the first compressor to the second compressor, and an apparatus for preparing ethylene for implementing the same.

A method for preparing ethylene, including: passing a feed stream containing C1 and C2 hydrocarbon compounds through a first heat exchanger and feeding the feed stream passed through the first heat exchanger to a second gas-liquid separator; feeding a part of a bottom discharge stream of the second gas-liquid separator to a demethanizer, passing an overhead discharge stream of the second gas-liquid separator through a second heat exchanger, feeding the overhead discharge stream of the second gas-liquid separator passed through the second heat exchanger to a third gas-liquid separator; feeding a bottom discharge stream of the third gas-liquid separator to the demethanizer; feeding a bottom discharge stream of the demethanizer to a C2 separator; feeding an overhead discharge stream of the C2 separator to a second compressor; passing a part of a compressed discharge stream of the second compressor through the first heat exchanger and feeding the part of the compressed discharge stream of the second compressor passed through the first heat exchanger to the second compressor as a first circulation flow; passing a part of the compressed discharge stream of the second compressor through the second heat exchanger and feeding the part of the compressed discharge stream of the second compressor passed through the second heat exchanger to a first compressor as a second circulation flow; and feeding a compressed discharge stream of the first compressor to the second compressor, and an apparatus for preparing ethylene for implementing the same.