Method for inhibiting polymerization during the recovery and purification of unsaturated mononitriles
US7282600B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 2004 |
| Grant date | Oct 16, 2007 |
| Priority date | — |
| Expiry date | Nov 26, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C253/32
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Economical processes are disclosed for recovery and refining of valuable nitrogen-containing organic compounds formed by catalytic oxidation of least one feed compound selected from the group consisting of propane, propylene, isobutane and isobutylene in the presence of ammonia to produce a gaseous. Processes of the invention include quenching the gaseous reactor effluent with an aqueous quench liquid; forming an aqueous solution comprising the corresponding unsaturated mononitrile, hydrogen cyanide and other organic co-products; and using an integrated sequence of distillations and phase separations to recover for recycle of a useful aqueous liquid, and obtain the desired nitrogen-containing products. According to the invention aqueous solutions are fractionated in an integrated system of multi-stage columns while an effective polymerization inhibiting amount of at least one member of a preselected class of p-phenylenediamine compounds is maintained therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.