Methods for preparing dibasic acids
US5922908A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1997 |
| Grant date | Jul 13, 1999 |
| Priority date | — |
| Expiry date | Mar 27, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2219/00777
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
This invention relates to methods of preparing dibasic acids, such as adipic acid for example, by oxidizing a hydrocarbon with a gas containing an oxidant, preferably oxygen. A respective hydrocarbon is reacted with a gaseous oxidant to form dibasic acid in a mixture which preferably contains a solvent, a catalyst, and an initiator. The temperature of the mixture is then lowered to a point at which solid dibasic acid is precipitated, while maintaining a single liquid phase. At least part of the formed acid is then removed. The lowering of the temperature is preferably performed at least partially by an operation selected from a group consisting of (a) evaporating at least part of the hydrocarbon or otherwise adjusting the hydrocarbon content of the mixture (b) lowering the pressure (c) adding matter having a temperature lower than the initial temperature (d) removing heat by external means (e) removing a first amount of heat by any suitable means, and adding a second amount of heat by external means, the first amount of heat being greater than the second amount of heat, and (f) a combination thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.