Draw solution for forward osmosis process

Patent metadata

Field	Value
Publication number	US-10087089-B2
Application number	US-201615040327-A
Country	US
Kind code	B2
Filing date	Feb 10, 2016
Priority date	Sep 29, 2010
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

wherein the molecular weight of the cation source in an uncharged state is 31 or greater and the Henry's law constant of each of the anion source and cation source is 1.0×104 (Pa/mol·fraction) or greater in a standard state.

First claim

What is claimed is:

1. A draw solution for a forward osmosis process, comprising an anion source and a cation source and water,
wherein the cation source has a molecular weight of 31 or greater in an uncharged state;
each of the anion source and cation source in water has a Henry's law constant of 1.0×10 4 (Pa/mol·fraction) or greater in a standard state;
each of the anion source and cation source in the draw solution has a concentration immediately prior to being contacted with the semi-permeable membrane of 2.4 mol or more per kilogram of water;
the anion source has an acid dissociation constant (pKa) of 6.0 to 7.0 as an uncharged material in a standard state; and
the cation source has a base dissolution constant (pKb) of 2.0 to 4.5 as an uncharged material in a standard state.

2. The draw solution for a forward osmosis process according to claim 1 , wherein each of the anion source and the cation source has a concentration of 2.4 mol or more per kilogram of the water.

3. The draw solution for a forward osmosis process according to claim 1 , wherein the anions are carbonate ions and/or hydrogen carbonate ions, and the cation source is one or more members selected from the group consisting of trimethyl amine, dimethyl ethyl amine, isopropyl amine, dimethyl amine, and diethyl amine.

4. The draw solution for a forward osmosis apparatus according to claim 1 , wherein the cation source contains a compound represented by formula (I):
R n —NH( 3−n )

wherein R denotes a linear or branched aliphatic group with 1 to 4 carbon atoms and n denotes 1, 2, or 3.

5. A forward osmosis apparatus, comprising a draw solution comprising an anion source, a cation source and water, wherein the cation source has a molecular weight of 31 or greater in an uncharged state, and each of the anion source and cation source in water has a Henry's law constant of 1.0×10 4 (Pa/mol·fraction) or greater in a standard state.

6. The forward osmosis apparatus according to claim 5 , wherein the anion source has an acid dissolution constant (pKa) of 6.0 to 7.0 as an uncharged material in a standard state.

7. The forward osmosis apparatus according to claim 5 , wherein the cation source has a base dissolution constant (pKb) of 2.0 to 4.5 as an uncharged material in a standard state.

8. The forward osmosis apparatus according to claim 5 , wherein the cation source in water has a Henry's law constant of 3.0×10 4 (Pa/mol·fraction) or greater in a standard state.

9. The forward osmosis apparatus according to claim 5 , wherein each of the anion source and the cation source has a concentration of 2.4 mol or more per kilogram of the water.

10. The forward osmosis apparatus according to claim 5 , wherein the anions are carbonate ions and/or hydrogen carbonate ions, and the cation source is one or more members selected from the group consisting of trimethyl amine, dimethyl ethyl amine, isopropyl amine, dimethyl amine, and diethyl amine.

Assignees

• Fujifilm Corp

Inventors

• Ikeda Morihito
• Miyamoto Kimiaki

Classifications

• B01D2311/2626

  Absorption or adsorption · CPC title

• C02F2209/02

  Temperature · CPC title

• C02F1/445 Primary

  by forward osmosis · CPC title

• B01D61/005

  Osmotic agents; Draw solutions · CPC title

• B01D61/002

  Forward osmosis or direct osmosis · CPC title