Process for the production of high purity terephthalic acid
US5166420A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1991 |
| Grant date | Nov 24, 1992 |
| Priority date | — |
| Expiry date | Oct 24, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/487
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the production of high purity terephthalic acid, by subjecting a crude terephthalic acid product, resulting from the oxidation of a paradialkylbenzene and containing a 4-carboxybenzaldehyde and other impurities at a relatively high level, to an efficient purification with high yield of terephthalic acid. This process comprises subjecting a high temperature aqueous solution of the crude terephthalic acid product to (A) an oxidation treatment with an oxygen-containing gas while feeding oxygen at a feed rate in the range of 0.4-10 moles per mole of the 4-carboxylbenzaldehyde contained in the crude terephthalic acid and then to (B) a treatment with hydrogen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.