Evonik Operations Gmbh

Christian Renner

Cornelia Borgmann

Axel Ronneburg

Imad Moussallem

Judith Hierold

Lucas Geist

Achim Fischer

Christian Reus

Anja Nordschild

Patrik Stenner

Stephan Rautenberg

Hans-Joachim Hasselbach

Philipp Roth

Bernd Drapal

Jürgen Bilz

Timo Stahl

Daniel Sudhoff

Andrea Kopp

Juergen Bilz

Danny De Corte

Tobias Winkler

Johannes Wefer

Christian Rückriegel

Ulf Bindernagel

Patrick Stenner

Christian RÜCKRIEGEL

The invention relates to a single cycle process for preparing D,L-methionine from an alkali methioninate solution obtained by alkaline hydrolysis of 5-(2-methylmercaptoethyl)hydantoin, in which the D,L-methionine is obtained by neutralizing the alkali methioninate solution with carbon dioxide at elevated temperature and subsequently crystallizing D,L-methionine in the presence of seed crystals.

Process for the preparation of D,L-methionine

The present invention pertains to a method for producing methionine or salts or derivatives thereof from hydrogen cyanide (HCN), the method comprising a step of producing 2-hydroxy-4-(methylthio)butyronitrile (MMP-CN), or a crude product mixture comprising MMP-CN, by contacting a hydrogen cyanide (HCN) process gas mixture prepared according to the Andrussow process from methane, ammonia and oxygen, with 3-methylmercaptopropionaldehyde (MMP), wherein the HCN process gas mixture is obtained from the crude HCN process gas mixture by adjusting the amount of ammonia to between 20% (v/v) and 60% (v/v) of the amount of the ammonia in the crude HCN process gas mixture.

Method for producing methionine

The present invention relates to a process for the preparation of methionine comprising the step of contacting a solution or suspension comprising 2-amino-4-(methylthio)butanenitrile and/or 2-amino-4-(methylthio)butaneamide with water in the presence of a catalyst to give a methionine comprising mixture, wherein the catalyst comprises CeO2 comprising particles, wherein the CeO2 comprising particles have a BET surface area of from 175 to 300+/−10% m2/g measured according to DIN ISO 9277-5 (2003), a mean maximum Feret diameter x, mean of from 3+/−10% to 40+/−10% nm and a mean minimum Feret diameter x, mean of from 2+/−10% to 30+/−10% nm, both measured according to DIN ISO 9276-6 (2012).

Process for the preparation of methionine

The present invention relates to a process for the preparation of methionine comprising the step of contacting a solution or suspension comprising 2-amino-4-(methylthio)butanenitrile and/or 2-amino-4-(methylthio)butaneamide with water in the presence of a catalyst to give a methionine comprising mixture, wherein the catalyst comprises CeOcomprising particles, wherein the CeOcomprising particles comprise from 50 to 100 wt.-% of CeO, have a BET surface area of from 35 to 65 m/g measured according to DIN ISO 9277-5 (2003), a mean maximum Feret diameter xof from 10 to 40 nm and a mean minimum Feret diameter xof from 5 to 30 nm, both measured according to DIN ISO 9276-6 (2012).

A chemical compound of formula (I), and specific compositions including 3-methylthiopropionaldehyde, 3-methylthiopropane-1,1-diol, a compound of formula I and water, and processes for producing same and also the use of same may be used for the production of 2-hydroxy-4-(methylthio)butyronitrile, methionine hydantoin, methionine. Protected forms may be used for the storage and/or transport of 3-methylthiopropionaldehyde.

Storage-stable form of 3-methylthiopropionaldehyde

The present invention pertains to a process for preparing guanidino acetic acid (GAA) from cyanamide and glycine in alkaline process solution, in which anionic impurities are removed from the process solution by electrodialysis.

Process for preparing guanidino acetic acid

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Gruendau, Germany

Christian Renner