Osmotic fluid purification and draw compounds thereof

Abstract

Draw compounds and draw solutions comprising said draw compounds for use in forward osmosis solvent purification systems. The draw compound may be a linear random, sequential, or block molecular chain consisting of at least one oxide monomer or diol monomer and have a temperature-dependent affinity with a feed solvent. The draw compound may further include a first terminal group and a second terminal group, at least one of the first terminal group and the second terminal group selected from the group consisting of a hydroxyl group, an amine group, a carboxylic group, an allyl group, and a C1 to C14 substituted and unsubstituted alkyl group. The draw compound may also be a branched random, sequential, or block molecular chain consisting of at least one oxide monomer or diol monomer.

What is claimed is: 
     
         1 . A draw compound for osmotic fluid purification, the draw compound comprising:
 a linear random, sequential, or block molecular chain including at least one oxide monomer selected from the group consisting of styrene oxide, epifluorohydrin, epichlorohydrin, oxetane, dioxilane, trioxane, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether, wherein the at least one oxide monomer is temperature-sensitive and has a temperature-dependent affinity with a feed solvent, and   wherein the draw compound further comprises a first terminal group and a second terminal group, at least one of the first terminal group and the second terminal group selected from the group consisting of a hydroxyl group, an amine group, a carboxylic group, an allyl group, and a C1 to C14 substituted and unsubstituted alkyl group.   
     
     
         2 . The draw compound according to  claim 1 , wherein the draw compound is a linear random oligomer or copolymer of ethylene oxide, propylene oxide, and butylene oxide. 
     
     
         3 . The draw compound according to  claim 1 , wherein the draw compound is a linear random oligomer or copolymer of ethylene oxide and propylene oxide. 
     
     
         4 . The draw compound according to  claim 3 , wherein the draw compound has a molecular weight of from 100 to 25,000. 
     
     
         5 . The draw compound according to  claim 3 , wherein the draw compound has an EO/PO ratio from 0.01 to 10.0. 
     
     
         6 . The draw compound according to  claim 3 , wherein the draw compound has a molecular weight of from 200 to 5,000. 
     
     
         7 . The draw compound according to  claim 3 , wherein the draw compound has a molecular weight of from 500 to 3,500. 
     
     
         8 . The draw compounds according to  claim 3 , wherein the draw compound has a molecular weight of from 800 to 2,800. 
     
     
         9 . The draw compound according to  claim 3 , wherein the draw compound has an EO/PO ratio from 0.01 to 10.0. 
     
     
         10 . The draw compound according to  claim 3 , wherein the draw compound has an EO/PO ratio from 0.05 to 5.0. 
     
     
         11 . The draw compound according to  claim 3 , wherein the draw compound has an EO/PO ratio from 0.1 to 1.0. 
     
     
         12 . The draw compound according to  claim 3 , wherein the draw compound has a cloud point temperature from 20° C. to 175° C. 
     
     
         13 . The draw compound according to  claim 3 , wherein the draw compound has a cloud point temperature from 35° C. to 125° C. 
     
     
         14 . The draw compound according to  claim 3 , wherein the draw compound has a cloud point temperature from 40° C. to 80° C. 
     
     
         15 . A draw compound for osmotic fluid purification, the draw compound comprising:
 a branched random, sequential, or block molecular chain including at least one oxide monomer or diol monomer, wherein the molecular chain including at least one oxide monomer or diol monomer is temperature-sensitive and has a temperature-dependent affinity with a feed solvent, and   wherein the draw compound further comprises a first terminal group and a second terminal group, at least one of the first terminal group and the second terminal group selected from the group consisting of a hydroxyl group, an amine group, a carboxylic group, an allyl group, and a C1 to C14 substituted and unsubstituted alkyl group.   
     
     
         16 . The draw compound according to  claim 15 , wherein the draw compound has three or more branches, each branch comprising one or more epoxide monomers selected from of the group consisting of ethylene oxide, propylene oxide, 1,2-epoxy-butane, 2,3-epoxy-butane, styrene oxide, epifluohydrin, epichlorohydrin, tetrahydrofuran, oxetane, dioxilane, trioxane, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether or each branch comprising one or more diol monomers selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-2-propyl-1,3-propanediol, neopentyl glycol, resorcinol, and 4,4′-(propane-2,2-diyl)diphenol. 
     
     
         17 . The draw compound according to  claim 15 , wherein the starting compound for the preparation of the draw compound is selected from the group consisting of vitamins and sugar alcohols. 
     
     
         18 . The draw compound according to  claim 15 , wherein the starting compound for the preparation of the draw compound is selected from the group consisting of polyols, glycerol, trimethylolpropane, pentaerythritol, diglycerol, ditrimethylolpropane, phloroglucinol, sorbitol, sorbitan, glucose, fructose, and methyl glucoside, or selected from the group consisting of ascorbic acid, glycerol, erythritol, threitol arabitol, ribitol, xylitol, fructitol, galacititol, iditol, inositol, mannitol, sorbitol, volemitol, isomalt, maltitol, and lactitol. 
     
     
         19 . The draw compound according to  claim 15 , wherein the draw compound is a branched random oligomer or copolymer of ethylene oxide, propylene oxide, and butylene oxide or copolymer of ethylene oxide and propylene oxide. 
     
     
         20 . The draw compound according to  claim 15 , wherein the draw compound has an EO/PO ratio from 0.01 to 10.0.