Process for the production of terephthalic acid
US5304676A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1992 |
| Grant date | Apr 19, 1994 |
| Priority date | — |
| Expiry date | Jan 30, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/52
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Terephthalic acid is produced by oxidation of para xylene, purified in an aqueous phase and recovered by precipitating a purified product from the aqueous phase, the aqueous phase mother liquor is then cooled or evaporated to produce a further less pure precipitate and a second mother liquor and the less pure precipitate is returned to the reaction medium and/or the water of the second mother liquor is used to dissolve the crude solid and/or the second mother liquor is treated to recover water which is used to wash the precipitate recovered from the aqueous solution. The process produces better yields of terephthalic acid, reduces the use of water and reduces problems in the disposal of polluted waste water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.