Purification of organic polycarboxylic acids
US5159109A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1991 |
| Grant date | Oct 27, 1992 |
| Priority date | — |
| Expiry date | Feb 19, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/445
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
There is provided a method for purifying an organic polycarboxylic acid wherein the amounts of organic monofunctional impurities associated therewith are substantially reduced, which method comprises conducting steam distillation of a stream comprising said polycarboxylic acid. In one embodiment of the method, a reactor effluent comprising a polycarboxylic acid is introduced into a crystallization zone, said effluent being subjected to crystallization and steam distillation coextensively in said crystallization zone. The method of the present invention may be used suitably to purify 1,4-cyclohexanedicarboxylic acid in a reactor effluent from the hydrogenation of a terephthalic acid by reducing the amounts of 4-methyl-1-cyclohexanecarboxylic acid and cyclohexanecarboxylic acid, as well as other organic impurities, contaminating the dicarboxylic acid. There is also provided the polycarboxylic acid purified by the method of the present invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.