Recovery of ethylene and propylene from a methanol to olefin reaction system

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 comprises ethane, ethylene, propane, propylene and dimethyl ether;
• (b) contacting the effluent stream with an oxygenate removal medium in an oxygenate removal unit under conditions effective to form a first overhead stream and a first bottoms stream, wherein the first overhead stream comprises residual oxygenate removal medium and a majority of the ethane, ethylene, propane, propylene, and dimethyl ether, and wherein the first bottoms stream comprises a minority of the dimethyl ether and a majority of the oxygenate removal medium;
• (c) contacting the first overhead stream with water under conditions effective to form a second overhead stream and a second bottoms stream, wherein the second overhead stream comprises a majority of the ethane, ethylene, propane, propylene, and dimethyl ether present in the first overhead stream, and wherein the second bottoms stream comprises a majority of the residual oxygenate removal medium present in the first overhead stream and a majority of the water;
• (d) separating at least a portion of the second overhead stream into a third overhead stream and a third bottoms stream, wherein the third overhead stream comprises a majority of the ethane and ethylene present in the at least a portion of the second overhead stream, and wherein the third bottoms stream comprises a majority of the propane, propylene and dimethyl ether present in the at least a portion of the second overhead stream;
• and
• (e) separating at least a portion of the third bottoms stream into a fourth overhead stream and a fourth bottoms stream, wherein the fourth overhead stream comprises a majority of the propylene present in the at least a portion of the third bottoms stream, and wherein the fourth bottoms stream comprises a majority of the propane and dimethyl ether present in the at least a portion of the third bottoms stream.

A process for separating components from an olefin-containing effluent stream, the process comprising the steps of:

• (a) providing the olefin-containing effluent stream, wherein the effluent stream contains ethane, ethylene, propane, propylene, dimethyl ether and one or more oxygenates, wherein the one or more oxygenates are selected from the group consisting of methyl ethyl ether, ethanol, isopropanol, acetic acid, propionic acid, ethanal, butanal, propanal, acetone, 2-butanone, 2-pentanone, 4-methyl-2-pentanone and methyl acetate;
• (b) contacting the effluent stream with an oxygenate removal medium in an oxygenate removal unit under conditions effective to form a first overhead stream and a first bottoms stream, wherein the first overhead stream contains a majority of the ethane, ethylene, propane, propylene, and dimethyl ether present in the effluent stream and residual oxygenate removal medium, and wherein the first bottoms stream contains a majority of the oxygenate removal medium, a majority of the oxygenates present in the effluent stream, and a minority of the dimethyl ether present in the effluent stream;
• (c) contacting the first overhead stream with water under conditions effective to form a second overhead stream and a second bottoms stream, wherein the second overhead stream contains a majority of the ethane, ethylene, propane, propylene, and dimethyl ether present in the first overhead stream, and wherein the second bottoms stream contains a majority of the residual oxygenate removal medium present in the first overhead stream and a majority of the water;
• (d) separating at least a portion of the second overhead stream into a third overhead stream and a third bottoms stream, wherein the third overhead stream contains a majority of the ethane and ethylene present in the at least a portion of the second overhead stream, and wherein the third bottoms stream contains a majority of the propane, propylene and dimethyl ether present in the at least a portion of the second overhead stream;
• and
• (e) separating at least a portion of the third bottoms stream into a fourth overhead stream and a fourth bottoms stream, wherein the fourth overhead stream contains a majority of the propylene present in the at least a portion of the third bottoms stream, and wherein the fourth bottoms stream contains a majority of the propane and dimethyl ether present in the at least a portion of the third bottoms stream.

A process for separating components from an olefin-containing effluent stream, the process comprising the steps of:

• (a) contacting an oxygenate with a molecular sieve catalyst composition in a reactor under conditions effective to form the effluent stream, wherein the effluent stream contains water, ethane, ethylene, propane, propylene, dimethyl ether and one or more oxygenate byproducts, wherein the oxygenate byproducts are selected from the group consisting of methyl ethyl ether, ethanol, isopropanol, acetic acid, propionic acid, ethanal, butanal, propanal, acetone, 2-butanone, 2-pentanone, 4-methyl-2-pentanone and methyl acetate;
• (b) cooling at least a portion of the effluent under conditions effective to form a quench overhead stream and a condensed stream, wherein the quench overhead stream comprises a majority of the ethane, ethylene, propane, propylene, dimethyl ether and the one or more oxygenate byproducts present in the effluent stream, and wherein the condensed stream contains a majority of the water present in the effluent stream;
• (c) contacting the quench overhead stream with an oxygenate removal medium in an oxygenate removal unit under conditions effective to form a first overhead stream and a first bottoms stream, wherein the first overhead stream contains a majority of the ethane, ethylene, propane, propylene, and dimethyl ether present in the quench overhead stream and residual oxygenate removal medium, and wherein the first bottoms stream contains a majority of the oxygenate removal medium, a majority of the oxygenate byproducts present in the quench overhead stream, and a minority of the dimethyl ether present in the quench overhead stream;
• (d) contacting the first overhead stream with water under conditions effective to form a second overhead stream and a second bottoms stream, wherein the second overhead stream contains a majority of the ethane, ethylene, propane, propylene, and dimethyl ether present in the first overhead stream, and wherein the second bottoms stream contains a majority of the residual oxygenate removal medium present in the first overhead stream and a majority of the water contacted with the first overhead stream in step (d);
• (e) separating at least a portion of the second overhead stream into a third overhead stream and a third bottoms stream, wherein the third overhead stream contains a majority of the ethane and ethylene present in the at least a portion of the second overhead stream, and wherein the third bottoms stream contains a majority of the propane, propylene and dimethyl ether present in the at least a portion of the second overhead stream;
• and
• (f) separating at least a portion of the third bottoms stream into a fourth overhead stream and a fourth bottoms stream, wherein the fourth overhead stream contains a majority of the propylene present in the at least a portion of the third bottoms stream, and wherein the fourth bottoms stream contains a majority of the propane and dimethyl ether present in the at least a portion of the third bottoms stream.