Process for making aromatic acids
US4034005A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1975 |
| Grant date | Jul 5, 1977 |
| Priority date | — |
| Expiry date | Jun 17, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/10
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for making an aromatic carboxylic acid of high purity by feeding an essentially equilibrium hydrolysis mixture of an aromatic nitrile to a reactive distillation column operated at a temperature of from about 200.degree. C. to about 325.degree. C. at autogenous pressure where the equilibrium mixture is subjected simultaneously to further hydrolysis and distillation of ammonia, removing water vapor and ammonia from the top of the column, subjecting remaining equilibrium hydrolysis mixture to further hydrolysis and distillation in a reboiler, returning vapor from the reboiler to the distillation column, removing an aqueous solution of product acid from the reboiler, cooling said separated solution, separating acid product, and in order to improve product purity, returning the aqueous filtrate from said separated acid product to a lower portion of said column. In one embodiment of the invention the hydrolysis mixture is obtained by subjecting a nitrile from the ammoxidation of an alkyl aromatic compound to aqueous hydrolysis in a closed reactor at about 200.degree. to about 325.degree. C. until an essentially complete equilibrium is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.