Patent ID: 8628642

Claim:
A processing plant 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) dissolved solids, and (iii) water, said processing plant comprising: (a) a distillation section comprising a single distillation column, wherein said distillation section is arranged to receive said feed mixture and to produce from said feed mixture 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) a first membrane separation section arranged to receive said first intermediate stream, said first membrane separation section comprising 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, wherein the first membrane separates 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) a second membrane separation section arranged to receive said second intermediate stream, said second membrane separation section comprising a second membrane having a dissolved solids rejection coefficient for selected solids of from about 65% to about 99.99%, wherein the second membrane separates 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.