Process to prepare a solid composition of an amino acid diacetic acid

Patent metadata

Field	Value
Publication number	US-10836709-B2
Application number	US-201816629259-A
Country	US
Kind code	B2
Filing date	Jul 3, 2018
Priority date	Jul 7, 2017
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A process for the preparation of a solid composition of an amino acid diacetic acid compound wherein the amino acid diacetic acid compound is methyl glycine-N,N-diacetic acid or a salt thereof, or glutamic N,N-diacetic acid or a derivative thereof, as well as the product obtained by such process are disclosed. The process includes feeding a saturated or oversaturated aqueous composition of the amino acid diacetic acid compound in an aqueous solvent to a drum dryer, wherein the aqueous composition is fed to the drum surface with a layer thickness of from about 0.1 to about 10 mm, the drum has a surface temperature of from about 80 to about 180° C., and the drum operates at a tangential speed of from about 0.1 to about 100 m/min. The method further includes removing the mass from the drum before a full revolution of the drum.

First claim

The invention claimed is:

1. A process for the preparation of a solid composition of an amino acid diacetic acid compound wherein the amino acid diacetic acid compound is methyl glycine-N,N-diacetic acid or a salt thereof, or glutamic N,N-diacetic acid or a derivative thereof, containing a step of
feeding a saturated or oversaturated aqueous composition of the amino acid diacetic acid compound in an aqueous solvent to a drum dryer, wherein the aqueous composition is fed to the drum surface with a layer thickness of 0.1-10 mm, the drum has a surface temperature of 80-180° C., and the drum operates at a tangential speed of 0.1-100 m/min; and
the mass is removed from the drum before a full revolution of the drum.

2. The process of claim 1 wherein the aqueous composition contains from about 45 to about 65 wt % of the amino acid diacetic acid compound on total aqueous composition.

3. The process of claim 1 wherein the amino acid diacetic acid compound is a sodium salt of methylglycine-N,N-diacetic acid.

4. The process of claim 1 wherein the composition contains from about 55 to about 65 wt % of the amino acid diacetic acid compound on total aqueous composition.

5. The process of claim 1 wherein the drum operates at a tangential speed of from about 1 to about 25 m/min.

6. The process of claim 1 wherein the solid composition is removed from the drum when the drum has completed between from about 40 to about 75% of a full revolution.

7. The process of claim 1 wherein the drum dryer is a double drum dryer.

8. The process of claim 1 wherein the drum has a surface temperature of 100-160° C.

9. The process of claim 1 wherein the aqueous composition has a residence time in the drum dryer of less than about 10 minutes.

10. The process of claim 1 wherein the aqueous composition is applied to the drum surface using nip-feeding.

11. The process of claim 1 wherein the aqueous composition is a slurry.

12. The process of claim 11 wherein the aqueous composition is a slurry containing crystals of the amino acid diacetic acid compound.

13. The process of claim 12 wherein the amino acid diacetic acid compound is the trisodium salt of MGDA and the crystals have the below crystal modification characterized by the d-values in angstroms corresponding to the respective diffraction angles 2 theta in ° in a X-ray powder diffraction pattern measured using Cu Kα irradiation shown below:

2Θ
d (Å)

8.2
10.8

10.5
8.4

15.6
5.7

16.5
5.4

17.1
5.2

18.1
4.9

18.8
4.7

21
4.25

21.4
4.15

22.6
3.9

23.7
3.75

24.7
3.6

14. The process of claim 1 wherein the amino acid diacetic acid is at least about 50% in the L-enantiomer form.

15. The process of claim 14 wherein the ratio L-enantiomer:
D-enantiomer of the amino acid diacetic acid is between from about 54:46 and to about 99:1.

Assignees

• Nouryon Chemicals Int Bv

Inventors

• Van Haeren Paulus Johannes Cornelis
• Doppen Roy
• Schomaker Elwin
• Vaessen Raymond Jean Cécile
• Ypma Marco
• Oudenhoven Stijn
• Heus Martin

Classifications

• C07C229/04

  the carbon skeleton being acyclic and saturated · CPC title

• C07C227/42 Primary

  Crystallisation · CPC title

• C07C227/00

  Preparation of compounds containing amino and carboxyl groups bound to the same carbon skeleton · CPC title

• C07C229/24

  having more than one carboxyl group bound to the carbon skeleton, e.g. aspartic acid · CPC title

• C07B2200/13

  Crystalline forms, e.g. polymorphs · CPC title