Process for the recovery of cobalt and tungstic acid and/or its derivatives from aqueous solutions

Patent metadata

Field	Value
Publication number	US-11603576-B2
Application number	US-201916573034-A
Country	US
Kind code	B2
Filing date	Sep 17, 2019
Priority date	Jan 22, 2015
Publication date	Mar 14, 2023
Grant date	Mar 14, 2023

Abstract

This invention relates to a process for the recovery of cobalt ions and tungstic acid and/or its derivatives from aqueous solutions, such as in particular the spent catalytic waters deriving from processes for the oxidative cleavage of vegetable oils. In particular this invention relates to a process for the recovery of cobalt ions and tungstic acid and/or its derivatives which provides for the use of cation-exchange resins.

First claim

The invention claimed is:

1. A process for oxidative cleavage of vegetable oils containing monounsaturated fatty acid triglycerides comprising:
1) A first step of hydroxylation of the double bond present in the monounsaturated fatty acid triglycerides in the presence of a catalyst comprising tungstic acid and/or its derivatives, to yield a vicinal diol,
2) a subsequent second step of oxidation of the vicinal diol in the presence of catalysts comprising cobalt salts, thereby obtaining a mixture comprising saturated monocarboxylic acids and saturated carboxylic acid triglycerides having more than one acid group,
3) A step of separation of an aqueous solution containing cobalt ions and tungstic acid and/or their derivatives from said mixture of step 2) and
4) A step of separation of cobalt ions from said aqueous solution of step 3) comprising the operations of:
a) removing the cobalt ions by placing said aqueous solution in contact with a cation-exchange resin;
b) separating said aqueous solution from said cation-exchange resin;
c) concentrating said aqueous solution obtained from stage b, thereby obtaining a concentrated aqueous solution containing tungstic acid and/or its derivatives, wherein said concentrated aqueous solution obtained at the end of step 4-c) is recycled as catalyst to said first step 1) of hydroxylation.

2. The process according to claim 1 wherein said tungstic add derivatives of step 1) Are selected from the group consisting of phosphotungstic acid, pertungstic acid and polytungstates and their cobalt salts.

3. The process according to claim 1 wherein said cobalt salts of step 2) are selected from the group consisting of cobalt acetate, cobalt chloride, cobalt sulfate, cobalt nitrate and cobalt bromide.

4. The process according to claim 1 wherein at, the end of step 4-c) the concentration of tungstic acid and/or its derivatives in the concentrated aqueous solution, expressed as tungsten concentration, is of between 10 and 15% by weight and the concentration of cobalt ions is of less than 50 ppm.

5. The process according to claim 1 , comprising before step 4-a) a preliminary purification step for separating an organic phase from said aqueous solution.

6. The process according to claim 5 , in which said separation of the organic phase is performed by decantation.

7. The process according to claim 6 , in which said decantation is performed in presence of an organic solvent.

8. The process according to claim 7 , in which said organic solvent is selected from the group consisting of n-hexane, n-heptane, n-octane, n-nonanoic acid and mixtures thereof.

9. The process according to claim 8 , in which said organic solvent is n-octane, nonanoic acid or mixtures thereof.

10. The process according to claim 1 , in which said cationic exchange resin is crosslinked.

11. The process according to claim 1 , in which said cation-exchange resin is of the acid type.

12. The process according to claim 11 , in which the functional group of said cation-exchange resin of the acid type is constituted by sulphonic groups.

13. The process according to claim 1 , in which said step 4-a) is performed with a ionic exchange column.

14. The process according to claim 13 , in which said aqueous solution is fed to step a) with a flow rate comprised between 1 and 50 BV*/h (LHSV).

15. The process according to claim 2 , wherein said cobalt salts of step 2) Are selected from the group consisting of cobalt acetate, cobalt chloride, cobalt sulfate, cobalt nitrate and cobalt bromide.

16. The process according to claim 2 , wherein at the end of step 4-c) the concentration of tungstic acid and/or its derivatives in the concentrated aqueous solution, expressed as tungsten concentration, is of between 10 and 15% by weight and the concentration of cobalt ions is of less than 50 ppm.

17. The process according to claim 3 , wherein at the end of step 4-c) the concentration of tungstic acid and/or its derivatives in the concentrated aqueous solution, expressed as tungsten concentration, is of between 10 and 15% by weight and the concentration of cobalt ions is of less than 50 ppm.

18. The process according to claim 2 , comprising before step 4-a) a preliminary purification step for separating an organic phase from said aqueous solution.

19. The process according to claim 4 , comprising before step 4-a) a preliminary purification step for separating an organic phase from said aqueous solution.

20. The process according to claim 4 , comprising before step 4-a) a preliminary purification step for separating an organic phase from said aqueous solution.

Assignees

• Novamont Spa

Inventors

• Borsotti Giampietro
• Digioia Francesca

Classifications

• C07C67/333

  by isomerisation; by change of size of the carbon skeleton (introduction or elimination of carboxyl groups C07C67/313, C07C67/32) · CPC title

• C07C51/245

  of keto groups or secondary alcohol groups · CPC title

• B01J39/20

  obtained by reactions only involving unsaturated carbon-to-carbon bonds · CPC title

• C02F1/42

  by ion-exchange (ion-exchange in general B01J) · CPC title

• C02F2101/32

  Hydrocarbons, e.g. oil · CPC title