Continuous process for refining glyoxal
US4065506A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1975 |
| Grant date | Dec 27, 1977 |
| Priority date | — |
| Expiry date | Apr 30, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C45/85
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
An improvement in a process for refining crude glyoxal solutions, especially those obtained by the oxidation of acid aldehyde with nitric acid, wherein the crude glyoxal solution, free of volatile acids, is neutralized, the glyoxal is transformed to the glyoxal semiacetal with an alcohol having 1 to 3 carbon atoms and, after separation of the salts and other impurities, is again hydrolized with water at elevated temperatures. The improvement described involves continuously extracting the glyoxal semiacetal formed with an organic solvent which is immiscible with water, hydrolyzing the extracted glyoxal semiacetal and refining the aqueous glyoxal solution obtained with active charcoal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.