US-12623188-B2 - Forward osmosis driven by electrolysis

Abstract

Systems and methods for removing a contaminant from a liquid are generally described. The liquid (e.g., water) containing the contaminant may be flowed across a semipermeable membrane (e.g., via forward osmosis) that is not permeable to the contaminant in order to remove the contaminant from the liquid. A concentration gradient across the semipermeable membrane may be provided and maintained by electrolysis of the liquid and can drive forward osmosis of the liquid through the semipermeable membrane.

Inventors

• Daniel G. Nocera
• Samuel S. Veroneau

Assignees

• PRESIDENT AND FELLOWS OF HARVARD COLLEGE

Dates

Publication Date

20260512

Application Date

20210519

Claims (20)

1. 1 . A system, comprising: a first volume configured to contain a liquid including at least one contaminant; a second volume configured to contain the liquid and an electrolyte; a first electrode disposed at least partially in the second volume; a second electrode disposed at least partially in the second volume; and a semipermeable membrane disposed between the first volume and the second volume, wherein the semipermeable membrane is permeable to the liquid, wherein the semipermeable membrane is configured to exclude the at least one contaminant from the second volume, and wherein the semipermeable membrane is configured to exclude the electrolyte from the first volume.
2. 2 . A system, comprising: a first volume configured to contain a liquid including at least one contaminant; a second volume configured to contain the liquid and an electrolyte; a first electrode disposed at least partially in the second volume; a second electrode disposed at least partially in the second volume; and a semipermeable membrane disposed between the first volume and the second volume, wherein the first and second electrodes are configured to electrolyze the liquid to provide a concentration differential across the semipermeable membrane to induce a flow of the liquid from the first volume to the second volume.
3. 3 . The system of claim 1 , further comprising a power source configured to apply a voltage differential to the first and second electrodes to electrolyze the liquid in the second volume.
4. 4 . The system of claim 1 , further comprising the liquid disposed in the first volume and the second volume and the electrolyte disposed in the first volume.
5. 5 . The system of claim 1 , further comprising a reference electrode disposed at least partially in the second volume.
6. 6 . The system of claim 1 , further comprising at least one conduit in fluid communication with the second volume, wherein the at least one conduit is configured to remove at least one electrolysis product from a head space of the second volume.
7. 7 . The system of claim 1 , wherein the semipermeable membrane is under an osmotic pressure of greater than or equal to 40 bar.
8. 8 . The system of claim 1 , wherein the semipermeable membrane is under an osmotic pressure of less than or equal than 80 bar.
9. 9 . The system of claim 1 , wherein the liquid comprises water.
10. 10 . The system of claim 1 , wherein the semipermeable membrane is permeable to the liquid.
11. 11 . The system of claim 1 , wherein the semipermeable membrane is configured to exclude the contaminant and/or the electrolyte.
12. 12 . The system of claim 1 , wherein the semipermeable membrane is configured to exclude the at least one contaminant and/or electrolyte from the second volume.
13. 13 . The system of claim 1 , wherein the electrolyte comprises potassium phosphate and/or methyl phosphonate.
14. 14 . The system of claim 1 , wherein the contaminant comprises a salt and/or a molecular compound soluble in the liquid.
15. 15 . The system of claim 2 , further comprising a power source configured to apply a voltage differential to the first and second electrodes to electrolyze the liquid in the second volume.
16. 16 . The system of claim 2 , further comprising the liquid disposed in the first volume and the second volume and the electrolyte disposed in the first volume.
17. 17 . The system of claim 2 , further comprising a reference electrode disposed at least partially in the second volume.
18. 18 . The system of claim 2 , further comprising at least one conduit in fluid communication with the second volume, wherein the at least one conduit is configured to remove at least one electrolysis product from a head space of the second volume.
19. 19 . The system of claim 2 , wherein the electrolyte comprises potassium phosphate and/or methyl phosphonate.
20. 20 . The system of claim 2 , wherein the semipermeable membrane is configured to exclude at least one contaminant and/or electrolyte from the second volume.

Description

RELATED APPLICATIONS This application is a national stage filing under 35 U.S.C. § 371 of international PCT application PCT/US2021/033055, filed May 19, 2021 which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63/057,642, filed Jul. 28, 2020, and to U.S. Provisional Application No. 63/027,733, filed May 20, 2020, each of which is incorporated herein by reference in its entirety for all purposes. GOVERNMENT SPONSORSHIP This invention was made with government support under N00014-19-1-2385 awarded by the Office of Naval Research. The government has certain rights in the invention. TECHNICAL FIELD Systems and methods for removing a contaminant from a liquid are generally described. BACKGROUND Purifying water for use in chemical processes at scale persists as a challenge, particularly for energy storage. For example, the desalination of saltwater (e.g., seawater) could provide an abundant amount of molecularly pure water for water-splitting systems. Water desalination often involves reverse osmosis by forcing saltwater across a semipermeable membrane that is not permeable to salt or other contaminants; however, such water desalination is energy-intensive and may rely upon expensive reverse osmosis plants when performing at scale and may also detract from eventual aims of energy storage. SUMMARY Systems and methods for removing a contaminant from a liquid are generally described. The liquid (e.g., water) containing the contaminant may flow through a semipermeable membrane (e.g., via forward osmosis) that is not permeable to the contaminant in order to remove the contaminant from the liquid. A concentration gradient across the semipermeable membrane can be provided and maintained by electrolysis of the liquid and can drive forward osmosis of the liquid through the semipermeable membrane. The subject matter of the present disclosure involves, in some cases, interrelated products, alternative solutions to a particular problem, and/or a plurality of different uses of one or more systems and/or articles as disclosed herein. In one aspect, a system is described comprising a first volume configured to contain a liquid including at least one contaminant, a second volume configured to contain the liquid and an electrolyte, a first electrode disposed at least partially in the second volume, a second electrode disposed at least partially in the second volume, and a semipermeable membrane disposed between the first volume and the second volume, wherein the semipermeable membrane is permeable to the liquid, wherein the semipermeable membrane is configured to exclude the at least one contaminant from the second volume, and wherein the semipermeable membrane is configured to exclude the electrolyte from the first volume. In another aspect, a system is described comprising a first volume configured to contain a liquid including at least one contaminant, a second volume configured to contain the liquid and an electrolyte, a first electrode disposed at least partially in the second volume, a second electrode disposed at least partially in the second volume, and a semipermeable membrane disposed between the first volume and the second volume, wherein the first and second electrodes are configured to electrolyze the liquid to provide a concentration differential across the semipermeable membrane to induce a flow of the liquid from the first volume to the second volume. In yet another aspect, a method is described comprising electrolyzing a liquid in a second volume containing an electrolyte to provide a concentration differential of the electrolyte in the second volume relative to a first volume containing the liquid and flowing the liquid from the first volume to the second volume through a semipermeable membrane. Other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments of the disclosure when considered in conjunction with the accompanying figures. In cases where the present specification and a document incorporated by reference include conflicting and/or inconsistent disclosure, the present specification shall control. BRIEF DESCRIPTION OF THE DRAWINGS Non-limiting embodiments of the present disclosure will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. In the figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the disclosure shown where illustration is not necessary to allow those of ordinary skill in the art to understand the disclosure. In the figures: FIG. 1 is a schematic diagram of a system for removing a contaminant from a liquid, according to some embodiments; FIG. 2 is a flowchart of a method for removing a contaminant from a