Method of using new solvents for forward osmosis

• US 9,962,656 B2
• Filed: 09/21/2016
• Issued: 05/08/2018
• Est. Priority Date: 09/21/2016
• Status: Expired due to Fees

• Current Assignee: Nrgtek Inc.
• Original Assignee: Nrgtek Inc.
• Inventors: Iyer, Subramanian
• Primary Examiner(s): Norris, Claire A
• Assistant Examiner(s): Wun, Julia L.
• Application Number:
  US15/272,406
• Publication Number:
  US 20180078901A1
• Time in Patent Office: 594 Days
• Field of Search: 210639, 210652
• CPC Class Codes: B01D 2313/221 Heat exchangers
• CPC Class Codes: B01D 61/002 Forward osmosis or direct osmosis
• CPC Class Codes: B01D 61/005 Osmotic agents; Draw solutions
• CPC Class Codes: B01D 61/02 Reverse osmosis; Hyperfiltration ; Nanofiltration
• CPC Class Codes: B01D 61/145 Ultrafiltration
• CPC Class Codes: B01D 61/58 Multistep processes
• CPC Class Codes: C02F 1/44 by dialysis, osmosis or reverse osmosis general membrane separation processes B01D61/00, membrane modules B01D63/00, electrodialysis C02F1/4693, combination of membrane modules and bioreactors C02F3/1268
• CPC Class Codes: C02F 1/445 by forward osmosis
• CPC Class Codes: C02F 2103/08 Seawater, e.g. for desalination
• CPC Class Codes: C02F 2303/16 Regeneration of sorbents, filters
• CPC Class Codes: Y02A 20/131 Reverse-osmosis

Abstract

A method is provided for using forward osmosis to remove impurities dissolved in an aqueous-based feed solution, where the method includes directing a solvent past a first side of a forward osmosis membrane and the feed solution is directed past a second side of the forward osmosis membrane, the solvent having a higher osmotic pressure than the feed solution so as to draw water across the membrane thereby diluting the solvent and concentrating the impurities in the feed solution, where the solvent is an amine-terminated branched PEG, such as amine-terminated glycerol ethoxylate, amine-terminated trimethylolpropane ethoxylate, or amine-terminated pentaerithritol ethoxylate, for example. The method further includes regenerating the solvent by exposing the diluted solvent to a gas containing CO2, whereby the CO2 is absorbed by the solvent, facilitating substantial separation of the solvent from water.

Claims

1. A method using forward osmosis for removing impurities dissolved in an aqueous-based feed solution, the method comprising directing a solvent past a first side of a forward osmosis membrane while the feed solution is directed past a second side of the forward osmosis membrane, the solvent having a higher osmotic pressure than the feed solution so as to draw water across the membrane thereby diluting the solvent, the solvent comprising an amine-terminated branched PEG.

2. The method of claim 1, wherein the solvent comprises amine-terminated glycerol ethoxylate.

3. The method of claim 1, wherein the solvent comprises amine-terminated trimethylolpropane ethoxylate.

4. The method of claim 1, wherein the solvent comprises amine-terminated pentaerythritol ethoxylate.

5. The method of claim 1, further comprising regenerating the solvent by exposing the diluted solvent to a gas containing CO₂, whereby the CO₂ is absorbed by the solvent, facilitating substantial separation of the solvent from water.