Process for recovering methacrylic acid
US4147721A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1978 |
| Grant date | Apr 3, 1979 |
| Priority date | — |
| Expiry date | Apr 6, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S203/22
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
In an oxidation process for converting methacrolein to methacrylic acid, methacrylic acid is recovered by cooling and condensing the effluent from the oxidation, followed by azeotropic distillation of the condensate with a suitable solvent, such as methyl n-propyl ketone. The condensed effluent contains methacrylic acid and water as the major components along with by-product acetic acid, a minor amount of unreacted methacrolein and impurities. Substantially dry crude methacrylic acid is separated as a bottom product from the azeotropic distillation and an azeotrope of water and the solvent is taken overhead and condensed. After condensation, solvent-rich and water-rich phases form and are separated. The solvent-rich phase is returned to the distillation column as a reflux, while the water-rich phase is sent to a stripping column for recovery of residual solvent. Water is withdrawn from the bottom of the stripping column and recycled or discarded, as desired. Optionally, an additional distillation column may be used in order to remove unreacted methacrolein from the solvent used in the azeotropic distillation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.