The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 18, 1984
Filed:
Dec. 17, 1981
Tzu-Ching Chang, Wilmington, DE (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A process of separating amines having different basicity constants is disclosed. The more reactive amine is converted to a salt which is extracted with water in a multiple stage countercurrent extractor. The salt form of the amine is converted to the free amine. In a preferred aspect of the invention the amine salt is an amine sulfite which can be converted to free amine and sulfur dioxide. The sulfur dioxide can be reused to generate more amine sulfite. The more reactive amine is then separated from the water and part of it recovered. The remainder of the more reactive amine is recycled to the countercurrent extractor. The less reactive amine is removed from the countercurrent extractor in the free amine state as an organic phase along with any organic solvent that is used. Part of the less reactive amine is recovered from the system while the remainder is converted to a salt and an aqueous solution thereof recycled to the countercurrent extractor.