Evonik Degussa Gmbh

Evonik Operations Gmbh

Evonik Industries Ag

Martin Koerfer

Hans Joachim Hasselbach

Caspar-Heinrich Finkeldei

Stephan Kretz

Pablo Zacchi

Harald Jakob

Dieter Buss

Martin Steurenthaler

Chiu Kee Cheung

Horst Krull

Michael R Rinner

Ralf Maassen

Stefan Wenner

Benjamin Fonfe

Caspar Heinrich Finkeldei

Stefan Reichert

Jignesh Gangadwala

Klaus Huthmacher

Christoph Weckbecker

Wolfgang Boeck

Bernd Drapal

Rainer Peter

Thorsten Merker

Juergen Stock

Christof P Gruener

Franz H Hanrath

Rainer Malzkorn

Dieter Greissinger

Stephan Rautenberg

Hans Christian Alt

Judith Hierold

Christian Kaiser

Winfried Heimbeck

Martin Steffan

Anja Nordschild

Sascha Ceylan

Michael Eicker

Dominik Egly

Wolfgang Polzer

Hans Albrecht Hasseberg

Bruno Krudewig

Wolfgang Moese

Gerit Niggemann

Haohao Zhu

Nongyuan Shi-Muenzenberg

Peter Schulte

Joachim Hans Hasselbach

Antje Hansmeier

Geert Van Eester

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 3-methylthiopropionaldehyde by reacting methyl mercaptan with acrolein, in which deviations in the stoichiometry of methyl mercaptan to acrolein in the reaction to give 3-methylthiopropionaldehyde are compensated for by supplying or by forming 1,3-bis(methylthio)-1-propanol, and also to the use of 1,3-bis(methylthio)-1-propanol as a storage form of methyl mercaptan and/or 3-methylthiopropionaldehyde.

Method for preparing 3-methylthiopropionaldehyde

The present invention relates to a process for purifying acrolein. The process includes the steps of a) splitting a liquid feed stream containing acrolein into at least a first liquid stream and a second liquid stream, b) introducing the first liquid stream with a temperature T1 into a distillation column at a point between the top and the bottom of the distillation column, c) introducing the second liquid stream with a temperature T2 into the distillation column at the top of the distillation column, d) withdrawing an overhead vapor stream enriched in acrolein from the distillation column, and e) withdrawing a bottom stream depleted in acrolein. The temperature T2 of the second liquid stream in step c) is lower than the temperature T1 of the first liquid stream in step b).

Process for the purification of acrolein

The present invention relates to a reactor and to a process for synthesis of hydrogen sulphide from elemental sulphur and hydrogen at elevated pressure and elevated temperature. The invention further relates to the use of the reactor for preparation of hydrogen sulphide in high yield and with a low HScontent.

Reactor and process for preparing hydrogen sulphide

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.

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Kahl, Germany

Martin Koerfer