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:
Sep. 15, 2015
Filed:
Mar. 27, 2014
Evonik Degussa Gmbh, Essen, DE;
Dieter Buss, Wesseling, DE;
Martin Steurenthaler, Frankfurt, DE;
Michael R. Rinner, Singapore, SG;
Stephan Kretz, Biebergemuend, DE;
Hans Joachim Hasselbach, Gelnhausen, DE;
Caspar-Heinrich Finkeldei, Alzenau, DE;
Martin Koerfer, Kahl, DE;
Pablo Zacchi, Bruchkoebel, DE;
EVONIK DEGUSSA GmbH, Essen, DE;
Abstract
A method for the production of 2-hydroxy-4-methylthiobutyric acid by hydrolysis of 2-hydroxy-4-(methylthio)butyronitrile is provided. 3-Methylmercaptopropionaldehyde is reacted with hydrogen cyanide in the presence of a base as catalyst in a main reaction zone of the multizone reactor to form a reaction mixture comprising the 2-hydroxy-4-(methylthio)butyronitrile, unreacted 3-methylmercaptopropionaldehyde, the catalyst and residual amounts of gaseous hydrogen cyanide. The residual gaseous hydrogen cyanide is removed from the main reaction zone to an absorption and post-reaction zone of the reactor which comprises a mixture of 3-methylmercaptopropionaldehyde and the catalyst; and the gaseous hydrogen cyanide is further reacted with the 3-methylmercaptopropionaldehyde in the absorption and post reaction zone. A molar ratio of hydrogen cyanide to 3-(methylthio)propanal in the main reaction zone is from 0.98 to 1.03.