Process for producing terephthalic acid of high purity
US4268690A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1979 |
| Grant date | May 19, 1981 |
| Priority date | — |
| Expiry date | Jul 2, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/52
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Terephthalic acid of high purity is continuously produced in a high yield by oxidizing p-tolualdehyde with a molecular oxygen-containing gas in the presence of bromine ions as a catalyst in a water solvent, contacting the resulting slurry solution containing crude terephthalic acid with an ascending stream of high temperature water of 180.degree.-320.degree. C., and withdrawing the water solvent together with the ascending stream of high temperature of water upwardly, while settling down crystalline terephthalic acid through the ascending stream of high temperature water and withdrawing the crystalline terephthalic acid together with a portion of the high temperature water downwardly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.