Methods for treating cobalt catalyst in oxidation mixtures resulting from oxidation of hydrocarbons to dibasic acids
US6232495A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 4, 1999 |
| Grant date | May 15, 2001 |
| Priority date | — |
| Expiry date | Feb 4, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/584
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention relates to methods and reactor devices for controlling the oxidation of hydrocarbons to dibasic acids, in the presence of a cobalt catalyst and a monobasic acid, such as acetic acid, by treating the catalyst from the reaction mixture, outside the oxidation zone, after the oxidation has taken place at least partially. In one preferred embodiment, the catalyst is reduced to contain, preferably predominantly and more preferably substantially, cobalt ions in valence II, and at least partially precipitated by de-watering and/or thermal treatment. In a different preferred embodiment, the catalyst in the reaction mixture is first oxidized or maintained, preferably predominantly and more preferably substantially, at valence III, the reaction mixture is de-watered, the catalyst is reduced, preferably predominantly and more preferably substantially, to valence II, causing precipitation either spontaneously at a predetermined temperature or after further thermal treatment. The precipitated catalyst is preferably recycled directly or indirectly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.