Membrane-based hybrid process for separation of mixtures of organics, solids, and water

A process for separating a feed mixture comprising (i) from about 1% to about 50% by weight of an organic substance whose normal boiling point is between 65° F. (18° C.) and the normal boiling point of water and that does not form a maximum boiling azeotrope with water, or whose normal boiling point is above the normal boiling point of water and that forms a minimum boiling azeotrope with water and (ii) from about 0.1% to about 40% by weight of dissolved solids with (iii) water as the balance, said process comprising:

• (a) distilling said feed mixture in a single distillation column at a pressure of from about 5 psig (136 KPa) to about 150 psig (1,136 KPa) and a temperature of from about 80° F. (27° C.) to about 450° F. (232° C.) to produce a first intermediate stream rich in said organic substance relative to said feed mixture and a second intermediate stream that is depleted of said organic substance and rich in said dissolved solids relative to said feed mixture, under conditions whereby said first intermediate stream contains from about 50% to about 99.5% by weight of said organic substance, but below the azeotropic concentration in case of azeotropic mixture;
• (b) passing at least a substantial fraction of said first intermediate stream through a first membrane at a pressure of from about 5 psig (136 KPa) to about 150 psig (1,136 KPa) and a temperature of from about 80° F. (27° C.) to about 450° F. (232° C.), in a mode selected from the group consisting of vapor permeation and pervaporation, said first membrane having a water permeation flux of from about 50 GPU to about 25,000 GPU and a ratio of water permeation flux to permeation flux of said organic substance of from about 25 or greater, to separate said first intermediate stream into a first product stream that is rich in said organic substance relative to said first intermediate stream and a second product stream that is depleted of said organic substance and rich in water relative to said first intermediate stream;
• and
• (c) passing said second intermediate stream through a second membrane at a pressure of from about 5 psig (136 KPa) to about 2500 psig (17,338 KPa) and a temperature of from about 50° F. (10° C.) to about 500° F. (260° C.), in a mode selected from the group consisting of ultrafiltration, nanofiltration, and reverse osmosis, said second membrane having a ratio of water permeation flux to transmembrane pressure drop of from about 0.001 GFD/psi to about 10 GFD/psi and a dissolved solids rejection coefficient for selected solids of from about 65% to about 99.99%, to separate said second intermediate stream into a third product stream that is rich in said dissolved solids relative to said second intermediate stream and a fourth product stream that is depleted of said dissolved solids and rich in water relative to said second intermediate stream.

A process for separating a feed mixture containing (i) from about 1% to about 50% by weight of an organic substance whose normal boiling point is between 65° F. (18° C.) and the normal boiling point of water and that does not form a maximum boiling azeotrope with water, or whose normal boiling point is above the normal boiling point of water and that forms a minimum boiling azeotrope with water and (ii) from about 0.1% to about 40% by weight of dissolved solids with (iii) water as the balance, said process comprising:

• (a) distilling said feed mixture in a single distillation column at a pressure of from about 5 psia (34 KPa) to about 50 psig (446 KPa) and a temperature of from about 50° F. (10° C.) to about 400° F. (204° C.) to produce a first intermediate stream rich in said organic substance relative to said feed mixture and a second intermediate stream that is depleted of said organic substance and rich in said solids relative to said feed mixture, under conditions whereby said first intermediate stream contains from about 50% to about 99.5% by weight of said organic substance, but below the azeotropic concentration in case of azeotropic mixture;
• (b) compressing said first intermediate stream to a pressure of from about 5 psig (136 KPa) to about 150 psig (1,136 KPa);
• (c) passing said first intermediate stream through a first membrane at a pressure of from about 5 psig (136 KPa) to about 150 psig (1,136 KPa) and a temperature of from about 80° F. (26° C.) to about 450° F. (232° C.), in vapor permeation mode, said first membrane having a water permeation flux of from 50 GPU to about 25,000 GPU and a ratio of water permeation flux to permeation flux of said organic substance of from about 25 or greater, said first membrane separating said first intermediate stream into a first product stream that is rich in said organic substance relative to said first intermediate stream and a second product stream that is depleted of said organic substance and rich in water relative to said first intermediate stream;
• and
• (d) passing said second intermediate stream through a second membrane at a pressure of from about 5 psig (136 KPa) to about 2500 psig (17,338 KPa) and a temperature of from about 50° F. (10° C.) to about 500° F. (260° C.), in a mode selected from the group consisting of ultrafiltration, nanofiltration, and reverse osmosis, said second membrane having a ratio of water permeation flux to transmembrane pressure drop of from about 0.001 GFD/psi to about 10 GFD/psi and a dissolved solids rejection coefficient for selected solids of from about 65% to about 99.99%, to separate said second intermediate stream into a third product stream that is rich in said dissolved solids relative to said second intermediate stream and a fourth product stream that is depleted of said dissolved solids and rich in water relative to said second intermediate stream.

A process for separating a feed mixture comprising (i) from about 1% to about 50% by weight of an organic substance whose normal boiling point is between 65° F. (18° C.) and the normal boiling point of water and that does not form a maximum boiling azeotrope with water, or whose normal boiling point is above the normal boiling point of water and that forms a minimum boiling azeotrope with water, (ii) ionized solids, and (iii) water, said process comprising:

• (a) distilling said feed mixture in a single distillation column to separate said feed mixture into a first intermediate stream rich in said organic substance relative to said feed mixture and a second intermediate feed stream that is depleted of said organic substance and rich in said ionized solids relative to said feed mixture, under conditions whereby said first intermediate stream contains from about 50% to about 99.5% by weight of said organic substance, but below the azeotropic concentration in case of azeotropic mixture;
• (b) passing at least a substantial fraction of said first intermediate stream through a first membrane that is selectively permeable to water and has a ratio of water permeation flux to flux of said organic substance of about 25 or greater, to separate said fraction of said first intermediate stream into
• a first product stream that is rich in said organic substance relative to said first intermediate stream and
• a second product stream that is depleted of said organic substance and rich in water relative to said first intermediate stream;
• and
• (c) passing at least a substantial fraction of said second intermediate stream through a second membrane operating in a member selected from the group consisting of an electrodialysis mode and an electrodialysis reversal mode to separate said fraction into
• a third product stream that is rich in said ionized solids relative to said second intermediate stream and
• a fourth product stream that is depleted of said ionized solids and rich in water relative to said second intermediate stream.