Evonik Degussa Gmbh

Degussa - Huls Ag

Evonik Operations Gmbh

Degussa Aktiengesellschaft

Evonik Industries Ag

Degussa Dental Gmbh & Co. Kg

Hans Joachim Hasselbach

Martin Koerfer

Klaus Huthmacher

Stephan Kretz

Christoph Weckbecker

Harald Jakob

Horst Weigel

Pablo Zacchi

Horst Krull

Caspar-Heinrich Finkeldei

Dieter Buss

Martin Steurenthaler

Harald Heinzel

Bernd Drapal

Michael R Rinner

Stefan Reichert

Jignesh Gangadwala

Steffen Krill

Benjamin Fonfe

Wolfgang Boeck

Hans Christian Alt

Volker Hafner

Nongyuan Shi

Rainer Peter

Caspar Heinrich Finkeldei

Juergen Stock

Christof P Gruener

Franz H Hanrath

Dominik Egly

Hans Albrecht Hasseberg

Mario Scholz

Steffen Hasenzahl

Hubert Redlingshöfer

Frank Hubner

Jan-Olaf Barth

Ralph McIntosh

Philipp Roth

Martin Körfer

Jürgen Bilz

Judith Hierold

Thorsten Merker

Christian Kaiser

Wolfgang Böck

Wolfram Binder

Daniel Fischer

Waldemar Hessberger

Martin Steffan

Jürgen Stock

Martin Korfer

Daniel Sudhoff

Markus Held

Sebastian Bernhardt

Heidemarie Kniesel

Gerit Niggemann

Benny Hartono

Martin K&ouml;rfer

Peter Schulte

Katja Kelm

Barbara Jager

Lutz Rohland

Antje Hansmeier

Christof P GRÜNER

Waldemar Heßberger

The present invention relates to a process for producing a particulate composition containing methionine, methionylmethionine, potassium in the form of potassium salt and ammonium sulphate, and use thereof.

Dipeptide-containing granular material

The present invention relates to a method for preparing methionine or methionine salts. In particular, the invention describes the step of preparing 2-hydroxy-4-(methylthio)butyronitrile (MMP-CN) from 3-methylthiopropanal (MMP) and hydrogen cyanide (HCN) in the presence of ammonia by bringing a gaseous mixture comprising HCN and ammonia into contact with MMP.

Method for preparing methionine

The present invention relates to a process for producing a particulate composition containing methionine, methionylmethionine, potassium in the form of potassium salt and ammonium sulfate, and use thereof.

Production method for dipeptide-containing granules

The invention relates to a method for crystallizing D,L-methionine from aqueous solutions and/or suspensions containing D,L-methionine and D,L-methionine ammonium salts, having a Met content of 70-180 g/kg, an NHcontent of 1-5 g/kg, in the presence of a crystallization additive, which comprises a nonionic or anionic surfactant or a mixture of various nonionic or anionic surfactants, in which the temperature of the solution and/or suspension is lowered directly or stepwise from T=85-110&#xb0; C. to T=30-50&#xb0; C., so that D,L-methionine precipitates as a solid.

Process for obtaining methionine

This disclosure relates to a process for preparing D,L-methionine by feeding carbon dioxide to an aqueous potassium methioninate solution obtained by hydrolysis of 5-(2-methylmercaptoethyl)hydantoin, in order to precipitate out crude methionine, which is separated off and purified. In this process an aqueous solution of the separated-off crude methionine is purified by recrystallization from a solution containing potassium ions and also a crystallization additive. The crystallization additive is a nonionic or anionic surfactant, or a mixture of different nonionic or anionic surfactants. The recrystallization occurs by introducing a 60 to 110&#xb0; C.-hot methionine solution into a 35 to 80&#xb0; C.-warm methionine suspension, a temperature of which is lower than that of the introduced solution, such that the temperature of the methionine suspension being maintained between 35 and 80&#xb0; C. during the addition. The crystallization additive is a sorbitan fatty acid ester or a mixture of different sorbitan fatty acid esters.

Process for the preparation of methionine

A method for production of a methionine salt in a reactive rectification column containing a weir having a height of 100 mm or more is provided.

Method of production of a methionine salt

A method to produce D,L-Methionine from 2-hydroxy-4-(methylthio)butyronitrile by reaction with ammonia, optionally in the presence of carbon dioxide, is provided. The 2-hydroxy-4-(methylthio)butyronitrile is obtained by reaction of 3-methylmercaptopropionaldehyde with hydrogen cyanide in the presence of a base as catalyst in a main reaction zone of a multizone reactor. 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.

Method for the production of D,L-methionine

The invention relates to a process for the preparation of D,L-methionine, in which carbon dioxide is fed to an aqueous potassium methioninate solution obtained by hydrolysis of 5-(2-methylmercaptoethyl)hydantoin, in order to precipitate out crude methionine, which is separated off and purified, where, for the purposes of purification, an aqueous solution of the separated-off crude methionine is prepared and subjected to a recrystallization, characterized in that the solution from which the recrystallization takes place contains potassium ions and also a crystallization additive, where the crystallization additive is a nonionic or anionic surfactant, or a mixture of different nonionic or anionic surfactants, and that the recrystallization takes place by introducing a 60 to 110&#xb0; C.-hot methionine solution into a 35 to 80&#xb0; C.-warm methionine suspension, the temperature of which is lower than that of the introduced solution, the temperature of the methionine suspension being maintained between 35 and 80&#xb0; C. during the addition.

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.

Method for the production of 2-hydroxy-4-(methylthio)butyronitrile from 3-(methylthio)propanal and hydrogen cyanide

A reactive rectification column suitable for the production of 2-hydroxy-4-methylmercaptobutyric acid and/or methionine contains a weir having a height of 100 mm or more.

Method for the conversion of methylmercaptopropionaldehyde formed from crude acrolein and crude methyl mercaptan

A reaction system suitable for production of a methionine salt contains a reactive rectification column containing a weir having a height of 100 mm or more.

A process for preparing methylmercaptopropionaldehyde in a single reaction unit, is provided. According to the preferred embodiment, the process comprises, simultaneously contacting a gaseous mixture comprising acrolein with a liquid mixture comprising methylmercaptopropionaldehyde, methyl mercaptan, a catalyst and methylmercaptopropionaldehyde methyl thiohemiacetal in the reactive absorber; absorbing the acrolein from the gaseous mixture into the liquid mixture; reacting the absorbed acrolein with the methyl mercaptan or the methylmercaptopropionaldehyde methyl thiohemiacetal to obtain methylmercapto-propionaldehyde; removing gaseous impurities and by-products from the liquid mixture; and separating the obtained methylmercaptopropionaldehyde product from the reactive absorber, directing a portion of the separated product to storage or further processing and recycling the remaining portion to the reactive absorber; wherein the methyl mercaptan optionally comprises dimethyl sulfide or dimethyl ether.

Process for preparing methylmercaptopropionaldehyde

A method for the production of 2-hydroxy-4-(methylthio)butyronitrile having good storage stability in a multi-zone reactor, 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.

The invention relates to a reaction vessel in which hydrogen sulphide is prepared from sulphur and hydrogen, wherein the reaction vessel consists partly or entirely of a material which is resistant to the reaction mixture, its compounds or elements and retains its resistance even at high temperatures.

Reaction vessel and process for its use

Growing community of inventors

Gelnhausen, Germany

Hans Joachim Hasselbach