Method to produce aromatic dicarboxylic acids using cobalt and zirconium catalysts
US6153790A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1998 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Dec 1, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/582
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process to produce terephthalic acid is provided, the process including the steps of: providing a feed stream comprising a dialkyl substituted aromatic and in an organic acid solvent: contacting the feed stream with an oxidant, the oxidant containing at least 50% by volume oxygen and at an oxygen partial pressure of at least 1 psia, at a temperature between about 80.degree. C. and about 130.degree. C., in the presence of a catalyst system comprising zirconium and cobalt, wherein the contacting is done in a stirred tank reactor; removing from the stirred tank reactor a vapor stream comprising the organic acid, water vapor and unreacted oxidant; condensing at least a portion of the organic acid and water from the vapor stream; separating at least a portion of the water from the organic acid back to the stirred tank reactor; returning at least a portion of the condensed organic acid back to the stirred tank reactor; continuously recovering from the stirred tank reactor a product comprising a diacid substituted aromatic; isolating solid crystals of diacid substituted aromatic from the reactor product; and recovering from the solid crystals a diacid substituted aromatic having a purit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.