Method for producing methionine

Patent metadata

Field	Value
Publication number	US-12187669-B2
Application number	US-201917413540-A
Country	US
Kind code	B2
Filing date	Dec 13, 2019
Priority date	Dec 14, 2018
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

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.

First claim

The invention claimed is:

1. A method for producing 2-hydroxy-4-(methylthio) butyronitrile (MMP-CN), comprising:
a) preparing a crude HCN process gas mixture by Andrussow HCN synthesis from methane, ammonia and oxygen;
b) preparing an HCN process gas mixture by adjusting the amount of ammonia in the crude HCN process gas mixture to between 20% (v/v) and 60% (v/v) of the amount present before adjustment; and
c) contacting the HCN process gas mixture with 3-methyl-mercaptopropionaldehyde (MMP).

2. The method of claim 1 , wherein the ammonia adjustment is performed using an ammonia scrubber equipped with a bypass stream.

3. The method of claim 1 , wherein the ammonia adjustment is performed using an ammonia scrubber enabling a partial ammonia breakthrough.

4. The method of claim 1 , wherein the ammonia is adjusted in step b) to about 40% (v/v) of the ammonia in the crude HCN process gas mixture.

5. The method of claim 4 , wherein adjustment is made using an ammonia scrubber.

6. A method for producing methionine, salts of methionine or derivatives of methionine from HCN, the method comprising:
a) preparing a crude HCN process gas mixture by Andrussow HCN synthesis from methane, ammonia and oxygen;
b) preparing an HCN process gas mixture by adjusting the amount of ammonia in the crude HCN process gas mixture to between 20% (v/v) and 60% (v/v) of the amount present before adjustment; and
c) contacting the HCN process gas mixture with 3-methyl-mercaptopropionaldehyde (MMP) to produce 2-hydroxy-4-(methylthio)-butyronitrile (MMP-CN), or a crude product mixture comprising MMP-CN; and
d) further reacting the MMP-CN or crude product mixture comprising MMP-CN of step c) to produce said methionine, salts of methionine or derivatives of methionine.

7. The method of claim 6 , wherein step d) comprises reacting the 2-hydroxy-4-(methylthio) butyronitrile (MMP-CN) or the crude product mixture comprising MMP-CN, with ammonia and/or ammonium salts and carbon dioxide and/or carbonic acid salts to give 5-(2-methylmercaptoethyl) hydantoin.

8. The method of claim 7 , wherein step d) further comprises reacting the 5-(2-methylmercapto-ethyl) hydantoin under basic conditions with formation of carbon dioxide and ammonia to give at least one methionine salt.

9. The method of claim 8 , wherein step d) further comprises reacting reacting the methionine salt with an acid to give methionine.

Assignees

• Evonik Operations Gmbh

Inventors

• Sudhoff Daniel
• Hierold Judith
• Roth Philipp
• Moussallem Imad
• Bindernagel Ulf
• Renner Christian

Classifications

• C07D233/76

  with substituted hydrocarbon radicals attached to the third ring carbon atom · CPC title

• C07C319/20 Primary

  by reactions not involving the formation of sulfide groups · CPC title

• C07C323/58

  with amino groups bound to the carbon skeleton · CPC title

• C07C323/60

  with the carbon atom of at least one of the carboxyl groups bound to nitrogen atoms · CPC title