Process for the purification of citric acid
US4113771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1977 |
| Grant date | Sep 12, 1978 |
| Priority date | — |
| Expiry date | Jun 17, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/487
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
It is disclosed that citric acid and salts thereof are readily produced by reacting acetone dicarboxyl ions, cyanide ions and alkali metal ions to produce an intermediate system which is subsequently reacted in an excess caustic system to form a salt of citric acid and that the salt is readily recovered by precipitation from the excess caustic system under proper conditions of concentration and temperature without requiring the formation of calcium salts. The recovered salt may be used directly or may be subjected to additional purification or may be converted to citric acid or other salts thereof by treatment with an acidification system such as sulfuric acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.