Method for purifying adipic acid by crystallization
US6538156B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1998 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Dec 4, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/43
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention discloses a method for purifying adipic acid by crystallization or recrystallization in at least one carbolyxic acid. More precisely, it discloses an improvement in adipic acid crystallization or recrystallization, characterised in that the said crystallization or recrystallization is effected in at least one carboxylic acid with a melting point below 20° C. The presence of carbon monoxide during crystallization or recrystallization can have a favourable effect on the adipic acid purity, in particular by reducing the content of metal catalyst traces of the adipic acid. The adipic acid purity can also be improved when the crystallization or recrystallization is effected in presence of a strong proton acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.