METHOD FOR PREPARING L-METHIONINE CRYSTALS USING CRYSTALLIZATION TECHNIQUE

• US 20190315682A1
• Filed: 12/29/2017
• Published: 10/17/2019
• Est. Priority Date: 12/30/2016
• Status: Active Grant

• Current Assignee: CJ Cheiljedang Corporation (CJ Group)
• Original Assignee: CJ Cheiljedang Corporation (CJ Group)
• Inventors: KIM, Jun-Woo, LEE, In Sung
• Granted Patent: US 10,870,619 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2009/0086 Processes or apparatus therefor
• CPC Class Codes: B01D 9/0013 by indirect heat exchange
• CPC Class Codes: B01D 9/0018 Evaporation of components of the mixture to be separated
• CPC Class Codes: B01D 9/0054 Use of anti-solvent
• CPC Class Codes: B01D 9/0059 General arrangements of crystallisation plant, e.g. flow sheets
• CPC Class Codes: B01D 9/0063 Control or regulation control per se G05
• CPC Class Codes: C07B 2200/13 Crystalline forms, e.g. polymorphs
• CPC Class Codes: C07C 319/20 by reactions not involving the formation of sulfide groups
• CPC Class Codes: C07C 319/28 Separation; Purification
• CPC Class Codes: C07C 323/58 with amino groups bound to the carbon skeleton

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.

Claims

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); 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 (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).

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

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

5. 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.

6. The method according to claim 3, wherein the coagulant is an aromatic compound.

7. The method according to claim 6, 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.

8. The method according to claim 3, wherein the coagulant is added in an amount of 2 to 7 parts by weight relative to 100 parts by weight of L-methionine.

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

C. to 90°

C.

10. The method according to claim 4, wherein the step of cooling is to cool to a temperature of 15°

C. to 35°

C.

11. The method according to claim 4, wherein the step of cooling is performed at a rate of 20°

C./h or less.

12. L-Methionine crystals prepared by the method of claim 1.

13. The method according to claim 3, 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.