Recovery of ethylene and propylene from a methanol to olefin reaction system
AssigneeExxonMobil Chemical Patents Inc.
InventorsCor F. Van Egmond, Jeffrey L. Brinen
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Abstract
The present invention provides new highly-efficient separation processes and systems for separating polymerization-grade ethylene and propylene from an initial effluent stream comprising ethane, ethylene, propylene, dimethyl ether, and one or more of propane, acetylene, methyl acetylene, propadiene, methane, hydrogen, carbon monoxide, carbon dioxide and C4+ components. In one embodiment, the initial effluent stream is provided from a methanol-to-olefin reaction system. It has been discovered that the best separation of these components is realized when DME is selectively removed in a first separation step, followed by separation of the remaining components in additional separation steps.
Claims111
A process for separating components from an olefin-containing effluent stream, the process comprising the steps of:
- (a) providing the effluent stream, wherein the effluent stream contains ethane, ethylene, propylene, and dimethyl ether;
- (b) separating the effluent stream in a first separation unit into a first fraction and a second fraction, wherein the first fraction contains a majority of the ethane, ethylene and propylene present in the effluent stream, and wherein the second fraction contains a majority of the dimethyl ether present in the effluent stream;
- and
- (c) separating at least a portion of the first fraction into a third fraction and a fourth fraction, wherein the third fraction contains a majority of the ethylene and ethane present in the at least a portion of the first fraction, and wherein the fourth fraction contains a majority of the propylene present in the at least a portion of the first fraction.
A process for separating components from an olefin-containing effluent stream, the process comprising the steps of:
- (a) providing the effluent stream, wherein the effluent stream contains methane, ethane, ethylene, propane, propylene, and dimethyl ether;
- (b) separating the effluent stream in a first separation unit into a first fraction and a second fraction, wherein the first fraction contains a majority of the methane, ethane, ethylene, propane and propylene present in the effluent stream, and wherein the second fraction contains a majority of the dimethyl ether present in the effluent stream;
- and
- (c) separating at least a portion of the first fraction into a third fraction and a fourth fraction, wherein the third fraction contains a majority of the methane that was present in the at least a portion of the first fraction, and wherein the fourth fraction contains a majority of the ethylene, ethane, propylene and propane that was present in the at least a portion of the first fraction.
A process for selectively hydrogenating acetylene, the process comprising the steps of:
- (a) providing an effluent stream containing methane, acetylene, ethylene, ethane, propylene, propane and dimethyl ether;
- (b) separating the effluent stream in a first separation unit into a first fraction and a second fraction, wherein the first fraction contains a first portion of the propane and a majority of the methane, ethane, ethylene and propylene present in the effluent stream, and wherein the second fraction contains a second portion of the propane and a majority of the dimethyl ether present in the effluent stream;
- (c) separating at least a portion of the first fraction into a third fraction and a fourth fraction, wherein the third fraction contains a majority of the methane, ethylene and ethane present in the at least a portion of the first fraction, and wherein the fourth fraction contains a majority of the propylene and propane present in the at least a portion of the first fraction;
- (d) separating at least a portion of the third fraction into a fifth fraction and a sixth fraction, wherein the fifth fraction contains a majority of the methane present in the at least a portion of the third fraction, and wherein the sixth fraction contains a majority of the ethylene and ethane present in the at least a portion of the third fraction;
- (e) separating at least a portion of the sixth fraction into a seventh fraction and an eighth fraction, wherein the seventh fraction contains a majority of the ethylene present in the at least a portion of the sixth fraction, and wherein the eighth fraction contains a majority of the ethane present in the at least a portion of the sixth fraction;
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- (f) contacting acetylene in an acetylene-containing stream with hydrogen and carbon monoxide in a conversion unit under conditions effective to at least partially hydrogenate at least a portion of the acetylene in the acetylene-containing stream, wherein the acetylene-containing stream is selected from the group consisting of the first fraction, the third fraction, the sixth fraction and the seventh fraction.
A process for separating components from an olefin-containing effluent stream, the process comprising the steps of:
- (a) providing the effluent stream, wherein the effluent stream contains ethane, ethylene, dimethyl ether, and propylene;
- (b) separating the effluent stream into a first fraction and a second fraction, wherein the first fraction contains at least 5 weight percent of the dimethyl ether and a majority of the ethane, ethylene and propylene present in the effluent stream, and wherein the second fraction contains at least 5 weight percent of the dimethyl ether and a majority of the C4+ components present in the effluent stream;
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- (c) separating at least a portion of the first fraction into a third fraction and a fourth fraction, wherein the fourth fraction contains a majority of the dimethyl ether present in the at least a portion of the first fraction.
Dependencies are inferred from the claim text.