A method for recovering paraxylene from a mixture of aromatic hydrocarbons. The process uses a pressure swing adsorption zone followed by a paraxylene recovery zone. The invention provides for lower throughput through the paraxylene recovery zone, resulting in lower capital costs and operating costs.

The present specification provides a method for preparing 1,3-butadiene, the method comprising: (A) obtaining a first product comprising a light component, 1,3-butadiene, and a heavy component from a reactant comprising butene; (B) separating the heavy component from a second product comprising the 1,3-butadiene and the light component by condensing the heavy component after heat exchanging the first product; and (C) separating concentrated heavy component by reboiling the condensed heavy component.

The present specification provides a method for preparing 1,3-butadiene, the method comprising: (A) obtaining a first product comprising a light component, 1,3-butadiene, and a heavy component from a reactant comprising butene; (B) separating the heavy component from a second product comprising the 1,3-butadiene and the light component by condensing the heavy component after heat exchanging the first product; and (C) separating concentrated heavy component by reboiling the condensed heavy component.

Methods and systems for treating an olefin-containing stream are disclosed. The disclosed methods and systems are particularly suitable for treating an off-gas stream in a refining or petrochemical process, such as from a fluid catalytic cracker (FCC), coker, steam cracker, and the like. The stream is treated in an absorber column to reject lighter stream components and to absorb ethylene and/or propylene into a solvent. The solvent is typically isobutane. The enriched solvent stream from the absorber column is fed to an alkylation reactor, which reacts the dissolved olefin with the isobutane solvent to produce an alkylate product.

Methods and systems for treating an olefin-containing stream are disclosed. The disclosed methods and systems are particularly suitable for treating an off-gas stream in a refining or petrochemical process, such as from a fluid catalytic cracker (FCC), coker, steam cracker, and the like. The stream is treated in an absorber column to reject lighter stream components and to absorb ethylene and/or propylene into a solvent. The solvent is typically isobutane. The enriched solvent stream from the absorber column is fed to an alkylation reactor, which reacts the dissolved olefin with the isobutane solvent to produce an alkylate product.

A process (100) is proposed for the production of one or more olefins, in which a reaction feed containing oxygen and one or more paraffins is formed and in which a part of the oxygen in the reaction feed is reacted with a part of the one or more paraffins to form the one or more olefins by an oxidative process, to obtain a process gas, the process gas containing at least the unreacted part of the one or more paraffins and oxygen, the one or more olefins, one or more acetylenes, carbon dioxide and water. The process comprises subjecting the process gas or a gas mixture formed using at least a part of the process gas partially or completely to a condensate separation (2), a compression (3), an at least partial removal (4) of the oxygen and acetylene(s) and to one or more stages of a carbon dioxide removal (5) in the order given herein, wherein the at least partial removal (4) of the oxygen and of the acetylene(s) is performed at the same time and by a catalytic conversion using a catalyst comprising copper oxide or ruthenium, and wherein the catalytic conversion is performed at least in part in the form of a hydrogenation. A corresponding plant is also the subject of the present invention.

A process (100) is proposed for the production of one or more olefins, in which a reaction feed containing oxygen and one or more paraffins is formed and in which a part of the oxygen in the reaction feed is reacted with a part of the one or more paraffins to form the one or more olefins by an oxidative process, to obtain a process gas, the process gas containing at least the unreacted part of the one or more paraffins and oxygen, the one or more olefins, one or more acetylenes, carbon dioxide and water. The process comprises subjecting the process gas or a gas mixture formed using at least a part of the process gas partially or completely to a condensate separation (2), a compression (3), an at least partial removal (4) of the oxygen and acetylene(s) and to one or more stages of a carbon dioxide removal (5) in the order given herein, wherein the at least partial removal (4) of the oxygen and of the acetylene(s) is performed at the same time and by a catalytic conversion using a catalyst comprising copper oxide or ruthenium, and wherein the catalytic conversion is performed at least in part in the form of a hydrogenation. A corresponding plant is also the subject of the present invention.

A method and a system for separating a feed flow which contains at least hydrogen and a hydrocarbon with three or four carbon atoms per molecule, in particular propane, propylene, propadiene, butane, 1-butene, 2-butene, and/or 1,3-butadiene. The condensed feed flow is cooled over multiple cooling steps in at least two heat exchangers and is then separated into a condensate and a residual gas flow after each cooling step. The at least two heat exchangers are operated at least two different temperature levels, wherein a hot heat exchanger is operated at an average temperature level, and a cold heat exchanger is operated at a lower temperature level. An internal refrigerant which is made of a part of one of the condensate flows and a part of one of the residual gas flows, is used to dispense a part of the heat from the cold heat exchanger.

A method and a system for separating a feed flow which contains at least hydrogen and a hydrocarbon with three or four carbon atoms per molecule, in particular propane, propylene, propadiene, butane, 1-butene, 2-butene, and/or 1,3-butadiene. The condensed feed flow is cooled over multiple cooling steps in at least two heat exchangers and is then separated into a condensate and a residual gas flow after each cooling step. The at least two heat exchangers are operated at least two different temperature levels, wherein a hot heat exchanger is operated at an average temperature level, and a cold heat exchanger is operated at a lower temperature level. An internal refrigerant which is made of a part of one of the condensate flows and a part of one of the residual gas flows, is used to dispense a part of the heat from the cold heat exchanger.

Methods and systems for steam cracking a mixed butane containing feed stream are disclosed. The feed stream includes n-butane and isobutane. The disclosed methods and systems entail splitting the feed into an enriched n-butane fraction and an enriched isobutane fraction. The enriched n-butane fraction is provided to the cracking furnaces, which yield the olefin products and also yield C4 species. The C4 species are partially hydrogenated and provided as a reactant feed to an alkylation reaction. The enriched isobutane fraction is also provided to the alkylation reaction, whereby high value alkylate product is produced. The disclosed methods and systems have increase olefins (especially ethylene) yield because the feed to the cracking process is enriched in n-butane. The economics are also improved because high value alkylate product is produced from a portion of the isobutane.