Method for preparing L-methionine crystals using crystallization technique

Patent metadata

Field	Value
Publication number	US-10870619-B2
Application number	US-201716469852-A
Country	US
Kind code	B2
Filing date	Dec 29, 2017
Priority date	Dec 30, 2016
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

The present application relates to a method for preparing L-methionine crystals with an improved bulk density. As the L-methionine crystals prepared according to the method for preparing L-methionine crystals of the present application may have a bulk density of up to 800 g/L, the L-methionine crystals are expected to reduce storage and transport costs of L-methionine powder and improve working conditions due to improved fluidity of the powder.

First claim

The invention claimed is:

1. A method for preparing L-methionine crystals, comprising:
(a) adding a pH control agent to an aqueous solution comprising L-methionine to lower or increase the pH, a step of pH adjustment;
(b) heating the aqueous solution comprising L-methionine, a step of heat treatment;
(b-2) adding a pH control agent to the aqueous solution comprising L-methionine to increase or lower the pH, a step of pH readjustment, between Step (b) and Step (c) or in Step (c); and
(c) extracting L-methionine crystals from the aqueous solution comprising L-methionine, which underwent pH adjustment and heat treatment, a step of extraction of crystals.

2. The method according to claim 1 , further comprising Step (b-1): adding a coagulant to the aqueous solution comprising L-methionine, a step of addition of a coagulant, before Step (b-2).

3. The method according to claim 1 , further comprising Step (b-3): cooling the aqueous solution comprising L-methionine, a step of cooling, before or during Step (c).

4. The method according to claim 1 , wherein when the pH control agent in the step of pH adjustment is a pH-increasing agent, the pH control agent in the step of pH readjustment is a pH-lowering agent, and when the pH control agent in the step of pH adjustment is a pH-lowering agent, the pH control agent in the step of pH readjustment is a pH-increasing agent.

5. The method according to claim 2 , wherein the coagulant is an aromatic compound.

6. The method according to claim 5 , wherein the aromatic compound is at least one compound selected from the group consisting of acetylsalicylic acid, acetaminophen, benzoic acid, salicylic acid, gallic acid, L-tyrosine, and L-phenylalanine.

7. The method according to claim 2 , wherein the coagulant is added in an amount of 2 to 7 parts by weight relative to 100 parts by weight of L-methionine.

8. The method according to claim 1 , wherein the step of heat treatment is to heat to a temperature of 40° C. to 90° C.

9. The method according to claim 3 , wherein the step of cooling is to cool to a temperature of 15° C. to 35° C.

10. The method according to claim 3 , wherein the step of cooling is performed at a rate of 20° C./h or less.

11. The method according to claim 2 , wherein when the pH control agent in the step of pH adjustment is a pH-increasing agent, the pH control agent in the step of pH readjustment is a pH-lowering agent, and when the pH control agent in the step of pH adjustment is a pH-lowering agent, the pH control agent in the step of pH readjustment is a pH-increasing agent.

Assignees

• Cj Cheiljedang Corp

Inventors

• Kim Jun-Woo
• Lee In Sung
• Koo Kee Kahb
• Kim Wang Soo
• Myerson Allan S

Classifications

• C07C319/20

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

• C07B2200/13

  Crystalline forms, e.g. polymorphs · CPC title

• B01D9/0059

  General arrangements of crystallisation plant, e.g. flow sheets · CPC title

• B01D9/0054

  Use of anti-solvent · CPC title

• B01D9/0018

  Evaporation of components of the mixture to be separated · CPC title