IP Library › Granted Patent US 12,370,527
Granted Patent B2
US 12,370,527 · App. 16/830,210 · Granted Jul 29, 2025

Systems and methods of regenerating activated carbon

Inventors: Ryan R. James (Columbus, OH); Kavitha Dasu (Powell, OH); Dinusha Siriwardena (Columbus, OH); Franco Pala (Rockland, MA); Ramona Darlington Iery (Columbus, OH)
Assignee: Revive Environmental Technology, LLC
B01J20/3475B01J20/20B01J20/3028B01J20/3416C02F1/283C02F2101/36C02F2101/40C02F2103/06C02F2303/16
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Quick Facts
Patent No.
US 12,370,527
App. No.
16/830,210
Filed
Mar 25, 2020
Granted
Jul 29, 2025
Kind
B2
Art Unit
1736
USPC
502/33
Abstract

The invention provides methods for regenerating activated carbon that have been used in absorbing per- and polyfluoroalkyl substances (PFAS) in aqueous solution. In these methods, the activated carbon is treated with a solution of base in alcohol, which has been found to impart superior properties to the activated carbon.

Claims (29)

1. A method of regenerating activated carbon contaminated by polyfluoroalkyl substances (PFAS) and/or perfluorooctane sulfonate (PFOS), comprising:

providing activated carbon having adsorbed polyfluoroalkyl substances (PFAS) and/or perfluorooctane sulfonate (PFOS);

contacting the activated carbon in a solution that comprises at least 50 mass % alcohol and at least 0.2 mass % of a base; and

separating the activated carbon from the solution.

2. A method of regenerating activated carbon contaminated by polyfluoroalkyl substances (PFAS) and/or perfluorooctane sulfonate (PFOS), comprising:

providing activated carbon having adsorbed polyfluoroalkyl substances (PFAS) and/or perfluorooctane sulfonate (PFOS);

contacting the activated carbon in a solution that comprises at least 50 mass % alcohol and at least 0.5 mass % of a base; and

separating the activated carbon from the solution.

3. The method of claim 1 further comprising rinsing the activated carbon that has been separated from the solution.

4. The method of claim 3 carried out in a batch process.

5. The method of claim 1 wherein the resulting activated carbon possesses about the same or superior adsorption of PFOS and/or PFOA (as measured by the sorption method in the Examples) as compared with the virgin activated carbon.

6. The method of claim 1 wherein the resulting activated carbon possesses superior adsorption of PFOS and/or PFOA (as measured by the sorption method in the Examples) as compared with the virgin activated carbon after exposure to PFAS for 2 days.

7. The method of claim 1 wherein the resulting activated carbon possesses superior desorption of PFOS and/or PFOA (as measured by the sorption method in the Examples) as compared with the virgin activated carbon.

8. The method of claim 1 wherein the resulting activated carbon possesses superior desorption of PFOS and/or PFOA (as measured by the sorption method in the Examples) as compared with the virgin activated carbon after exposure to PFAS for 2 days.

9. The method of claim 1 wherein the solution that is separated from the activated carbon is distilled to produce an alcohol solution that is recycled and used again regenerate activated carbon.

10. The method of claim 1 wherein the step of contacting comprises immersion, rinsing, and/or spraying.

11. The method of claim 1 wherein the step of contacting comprises rinsing at least 3 times with a volume of solution that is at least equal to the volume of activated carbon.

12. The method of claim 1 wherein the solution comprises at least 60, 70, 80, 90, or 95 mass % alcohol.

13. The method of claim 1 wherein the solution comprises at least 90 mass % alcohol and at least 0.5 mass % of NH4OH and wherein the alcohol is selected from ethanol, propanol and combinations thereof.

14. The method of claim 1 wherein the activated carbon is granulated activated carbon derived from coal.

15. The method of claim 1 wherein the activated carbon is granulated activated carbon that has been disposed underground and exposed to groundwater comprising PFAS.

16. The method of claim 1 wherein the regenerated activated carbon has at least 10% greater desorption of PFOA or PFOS (as measured by the sorption method in the Examples) as compared with virgin activated carbon.

17. The method of claim 1 wherein the activated carbon is regenerated in a flow of the alcohol and base solution.

18. The method of claim 1 wherein the step of contacting is conducted for at least 1 minute or at least 2 minutes, or at least 10 minutes, or at least 100 minutes, or 1 to 1000 minutes.

19. A system for regenerating activated carbon, comprising:

a vessel comprising activated carbon having an inlet and an outlet, and the activated carbon having adsorbed polyfluoroalkyl substances (PFAS); and

a distillation column connected to the outlet of the vessel; and

wherein an alcohol solution comprising at least 0.2 mass % base is present in the system.

20. The system of claim 19 wherein the alcohol solution comprises at least 70 mass % alcohol and at least 0.5 mass % base.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 10, 2023
From: BATTELLE MEMORIAL INSTITUTE
To: REVIVE ENVIRONMENTAL TECHNOLOGY, LLC
Reel/Frame 063916/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 29, 2023
From: JAMES, RYAN R.; DASU, KAVITHA; SIRIWARDENA, DINUSHA; PALA, FRANCO; IERY, RAMONA DARLINGTON
To: BATTELLE MEMORIAL INSTITUTE
Reel/Frame 063786/0246 →
Continuity (2)
Provisional Application 62823570 · Mar 25, 2019
Related Publication 20200306726A1 · Oct 1, 2020
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