Process for the preparation of methionine

Patent metadata

Field	Value
Publication number	US-11897836-B2
Application number	US-202017618145-A
Country	US
Kind code	B2
Filing date	Jun 8, 2020
Priority date	Jun 13, 2019
Publication date	Feb 13, 2024
Grant date	Feb 13, 2024

Abstract

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 Fmax , mean of from 3+/−10% to 40+/−10% nm and a mean minimum Feret diameter x Fmin , mean of from 2+/−10% to 30+/−10% nm, both measured according to DIN ISO 9276-6 (2012).

First claim

The invention claimed is:

1. A process for producing methionine, the process comprising contacting a solution or suspension comprising at least one selected from the group consisting of 2-amino-4-(methylthio)butanenitrile and 2-amino-4-(methylthio)butaneamide with water in the presence of a catalyst to give a methionine comprising mixture, wherein the catalyst comprises CeO 2 comprising particles, wherein the CeO 2 comprising particles have a BET surface area of 225+/−10% to 300+/−10% m 2 /g measured according to DIN ISO 9277-5 (2003), a mean maximum Feret diameter x Fmax, mean of 3+/−10% to 40+/−10% nm, a mean minimum Feret diameter x Fmin, mean of 2+/−10% to 30+/−10% nm, and a mean aspect ratio x Fmin, mean /x Fmax, mean of 0.55+/−10% to 0.80+/−10%, each measured according to DIN ISO 9276-6 (2012).

2. The process of claim 1 , wherein the catalyst comprises 25 to 100 wt.-% CeO 2 , based on a total weight of the catalyst.

3. The process of claim 1 , wherein the CeO 2 comprising particles comprise 50 to 100 wt.-% CeO 2 , based on a total weight of the CeO 2 comprising particles.

4. The process of claim 1 , wherein the BET surface area of the CeO 2 comprising particles is 225+/−10% to 265+/−10% m 2 /g.

5. The process of claim 1 , wherein the CeO 2 comprising particles have a lattice plane distance of 0.24+/−10% to 0.32+/−10% nm.

6. The process of claim 1 , wherein the CeO 2 comprising particles comprise octahedral particles.

7. The process of claim 1 , wherein the CeO 2 comprising particles have a mean equivalent circular diameter x A, mean of 3+/−10% to 30+/−10% nm, measured according to DIN ISO 9276-6 (2012).

8. The process of claim 1 , wherein the CeO 2 comprising particles have a crystallinity of at least 50%.

9. The process of claim 1 , wherein the contacting is performed at a temperature no greater than 90° C. with a 2-amino-4-(methylthio)butanenitrile comprising solution or suspension.

10. The process of claim 1 , further comprising contacting the methionine comprising mixture with water in the presence of the catalyst.

11. The process of claim 10 , wherein the contacting of the methionine comprising mixture is performed at a temperature of 70 to 140° C.

12. The process of claim 1 , further comprising separating the catalyst from the methionine comprising mixture by a continuous cross flow filtration.

13. The process of claim 1 , wherein the method further comprises vacuum distilling the methionine comprising mixture or stripping the with water vapor following the contacting.

Assignees

• Evonik Operations Gmbh

Inventors

• Bilz Jürgen
• Borgmann Cornelia
• Fischer Achim
• Geist Lucas
• Nordschild Anja
• Renner Christian
• Reus Christian
• Ronneburg Axel

Classifications

• 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