Process for the hydrolysis of dicarboxylic acid triglycerides

Patent metadata

Field	Value
Publication number	US-11028036-B2
Application number	US-201716306154-A
Country	US
Kind code	B2
Filing date	Jun 5, 2017
Priority date	Jun 6, 2016
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

This invention relates to an improved hydrolysis process for the preparation of dicarboxylic acids in which an organic phase comprising triglycerides of carboxylic acids having more than one acid functional group and a mixture comprising dicarboxylic acids, glycerine and partial esters of glycerine are mixed with water and hydrolysed at temperatures of between 50 and 350° C., and at pressures of or above the equilibrium vapor pressure. This process makes it possible to obtain high hydrolysis yields, even in short times.

First claim

The invention claimed is:

1. A process for the preparation of dicarboxylic acids from triglycerides of carboxylic acids having more than one acid functional group comprising the steps of:
a) mixing water with an organic phase consisting of triglycerides of carboxylic acids having more than one acid function and from 3 to 20% by weight with respect to the weight of the organic phase of a mixture comprising partial esters of glycerine with at least a dicarboxylic acid; and
b) hydrolysing the mixture obtained at the end of step a) in one or more hydrolysis reactors at temperatures of between 150 and 350° C., and at pressures corresponding to or higher than the equilibrium vapor pressure;
c) separating the dicarboxylic acids from the hydrolysis product obtained in step b).

2. The process according to claim 1 in which the said organic phase of step a) comprises from 0.01 to 15% by weight, of partial esters of glycerine with respect to the weight of the organic phase.

3. The process according to claim 1 in which the mixture comprising partial esters of glycerine of step a) further comprises dicarboxylic acids and/or glycerine.

4. The process according to claim 2 in which the said mixture comprises with respect to the sum of the areas of the peaks of components i-iv from the GC analysis:
i) from 20 to 80% of dicarboxylic acids;
ii) from 0.5 to 30% of glycerine;
iii) from 0.5 to 70% of partial esters of glycerine; and
iv) from 0 to 30% of monocarboxylic acids.

5. The process according to claim 1 , in which the said mixture comprising partial esters of glycerine is prepared from the hydrolysis product obtained in step b).

6. The process according to claim 5 in which the said mixture is further prepared by means of one or more operations selected from crystallisation, solvent extraction or concentration.

7. The process according to claim 1 in which the ratio by weight between the quantity of water and organic phase in step a) is between 1:2 and 5:1.

8. The process according to claim 1 in which step b) is carried out at temperatures between 240 and 320° C. and at pressures of between 40 and 110 bar.

9. The process according to claim 8 in which step b) is carried out at temperatures between 260 and 310° C. and at pressures of between 67 and 110 bar.

10. The process according to claim 8 in which the reaction time for step b) is between 1 and 60 minutes.

11. The process according to claim 1 in which the said reactors in step b) are plug flow tubular reactors.

12. The process according to claim 1 in which the said mixture constituting from 3 to 20% by weight of the organic phase in step a) comprises, with respect to the sum of the areas of the peaks relating to components i-iv, from the GC analysis:
i) from 40 to 70% of dicarboxylic acids;
ii) from 10 to 30% of glycerine;
iii) from 1 to 20% of partial esters of glycerine (glycerides); and
iv) from 0 to 20% of monocarboxylic acids,
and in which step b) is carried out at a temperature below 285° C. and a pressure of between 75 and 95 bar, for times of between 15 and 25 minutes.

13. The process according to claim 1 in which the said organic phase in step a) is prepared by premixing triglycerides of carboxylic acids having more than one acid functional group and the said mixture comprising partial esters of glycerine.

14. The process according to claim 1 in which the said triglycerides of carboxylic acids having more than one acid functional group are prepared from triglycerides of unsaturated carboxylic acids present in vegetable oils or animal fats through oxidative cleavage reactions.

15. The process according to claim 14 in which the said triglycerides of unsaturated carboxylic acids are obtained by oxidative cleavage processes in which peroxides and O 2 or mixtures containing O 2 are used.

16. The process according to claim 1 carried out starting from vegetable oils comprising triglycerides of unsaturated acids and comprising, before step a), the steps of:
1) reacting the said triglycerides of unsaturated carboxylic acids with an oxidising agent and a catalyst, activating the oxidisation reaction of the olefin double bond in order to obtain an intermediate compound containing vicinal diols, and
2) reacting the said intermediate compound containing vicinal diols, an oxidising agent containing molecular oxygen and a catalyst activating the oxidation reaction of the vicinal diols to carboxyl groups, obtaining monocarboxylic acids and triglycerides having more than one acid functional group; and
3) separating out a fraction of the said monocarboxylic acids, obtaining a mixture comprising the said triglycerides of carboxylic acids having more than one acid functional group.

17. The process according to claim 2 in which the mixture comprising partial esters of glycerine of step a) further comprises dicarboxylic acids and/or glycerine.

18. The process according to claim 2 , in which the said mixture comprising partial esters of glycerine is prepared from the hydrolysis product obtained in step b).

19. The process according to claim 3 , in which the said mixture comprising partial esters of glycerine is prepared from the hydrolysis product obtained in step b).

20. The process according to claim 4 , in which the said mixture comprising partial esters of glycerine is prepared from the hydrolysis product obtained in step b).

Assignees

• Novamont Spa

Inventors

• Digioia Francesca

Classifications

• C07C55/02

  Dicarboxylic acids · CPC title

• C07C51/09 Primary

  from carboxylic acid esters or lactones · CPC title

• C07C55/18

  Azelaic acid · CPC title