Process for recovering and purifying unreacted acrylonitrile from the waste stream in the manufacture of 2-acrylamido-2-methyl propane sulfonic acid
US4808344A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 1988 |
| Grant date | Feb 28, 1989 |
| Priority date | — |
| Expiry date | Feb 10, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S203/03
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Excess amounts of a pure form of acrylonitrile are reacted with other reactants in the production of various compounds such as 2-acrylamido-2-methyl propane sulfonic acid. Accordingly, large amounts of acrylonitrile remain unreacted and present with other contaminants. The present invention is directed toward the purification of such unreacted acrylonitrile and the purified acrylonitrile obtained from such a purification process. The purification is carried out by treating the unreacted acrylonitrile with a base and removing salts formed. The treated material is fed to a heat exchanger which heats the material preferably under vacuum to about 120.degree. F. and provides a heated fluid material. This heated fluid material is pumped to a lower area of a distillation tower which is maintained under vacuum and includes a plurality of distillation trays. Purified acrylonitrile has a lower boiling point and is drawn toward the top of the tower by vacuum and removed whereas the remainder of the material which includes contaminants has a higher boiling point and falls to the bottom of the tower. This bottom portion is removed and recycled to the heat exchanger. The purified acrylonitrile r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.