US3872166A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improvement in the recovery of glyoxylic acid
Assignee: Individual
•
Filing: 1973-06-25
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Granted: 1975-03-18
•
Expires: 1993-06-25
Abstract
Abstract A process for the recovery of glyoxylic acid as a byproduct in the synthesis of glyoxal by elution of the ion exchanger used for purifying the glyoxal and crystallization of sodium glyoxylate at a pH of from 3 to 6 from the aqueous eluate.
Inventors
- 👤 Hermann Spaenig
- 👤 Toni Dockner
- 👤 Helmut Karn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:01
CPC Classifications
C; C07; C07C; C07C59/00; C07C59/147; C07C59/153; C07C51/00; C07C51/42
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
94 words
A PROCESS FOR THE RECOVERY OF PURE GLYOXYLIC ACID OR SODIUM GLYOXYLATE FROM THE REGENERATION LIQOUR OBTAINED IN THE TREATMENT OF REACTION MIXTURES FROM THE PRODUCTION OF GLYOXAL WITH A BASIC ION EXCHANGER AND ELUTION OF THE ION EXCHANGER WHEREIN THE ION EXCHANGER CONTAINING GLYOXYLIC ACID IS ELUTED WITH CAUSTIC SODA SOLUTION, SODIUM CARBONATE SOLUTION OR SODIUM BICARBONATE SOLUTION, THE EULATE CONTAINING FROM 1 TO 15 PERCENT OF GLYOXYLIC ACID IS ADJUSTED TO A PH OF FROM 3 TO 6 CONCENTRATED TO SUCH AN EXTENT, WITH OR WITHOUT COOLING, THE SODIUM GLYOXYLATE IS PRECIPITATED.
Claim 2
Dependent Claim
94 words
A PROCESS FOR THE RECOVERY OF PURE GLYOXYLIC ACID OR SODIUM GLYOXYLATE FROM THE REGENERATION LIQOUR OBTAINED IN THE TREATMENT OF REACTION MIXTURES FROM THE PRODUCTION OF GLYOXAL WITH A BASIC ION EXCHANGER AND ELUTION OF THE ION EXCHANGER WHEREIN THE ION EXCHANGER CONTAINING GLYOXYLIC ACID IS ELUTED WITH CAUSTIC SODA SOLUTION, SODIUM CARBONATE SOLUTION OR SODIUM BICARBONATE SOLUTION, THE EULATE CONTAINING FROM 1 TO 15 PERCENT OF GLYOXYLIC ACID IS ADJUSTED TO A PH OF FROM 3 TO 6 CONCENTRATED TO SUCH AN EXTENT, WITH OR WITHOUT COOLING, THE SODIUM GLYOXYLATE IS PRECIPITATED.
Claim 3
Dependent Claim
19 words
A process as claimed in claim 1 wherein glyoxylic acid is liberated from the precipitated sodium glyoxylate by acidification.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |