US4073747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Regeneration of spent activated carbon with formaldehyde
Assignee: United States Department of Agriculture
•
Filing: 1976-12-13
•
Granted: 1978-02-14
•
Expires: 1996-12-13
Abstract
Abstract Spent activated carbon is regenerated by contacting it with formaldehyde in an amount sufficient to restore its activation. Following the treatment the regenerated carbon is rinsed to remove residual formaldehyde and is then ready for use.
Inventors
- 👤 Karel Popper
- 👤 Wayne M. Camirand
- 👤 Gerald S. Williams
- 👤 Edward P. Mecchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:43
CPC Classifications
C; C01; C01B; C01B32/00; C01B32/30; C01B32/354; C01B32/36
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
44 words
A process for regenerating spent carbon, which comprises contacting the spent carbon with an aqueous solution of formaldehyde in an amount sufficient to and for a period long enough to regenerate the carbon and removing the aqueous solution of formaldehyde from the regenerated carbon.
Claim 2
Dependent Claim
44 words
A process for regenerating spent carbon, which comprises contacting the spent carbon with an aqueous solution of formaldehyde in an amount sufficient to and for a period long enough to regenerate the carbon and removing the aqueous solution of formaldehyde from the regenerated carbon.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein the regenerated carbon is rinsed with water to remove residual formaldehyde.
References Cited (Backward Citations)
US3714040A
Cited
DE2129459A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |