Method for synthesising glycolic acid

Patent metadata

Field	Value
Publication number	US-9550715-B2
Application number	US-201414896969-A
Country	US
Kind code	B2
Filing date	May 26, 2014
Priority date	Jun 10, 2013
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

The invention relates to a method for synthesizing glycolic acid or one of the salts thereof, including the following step: placing glycerol and an oxidizing agent in contact with one another in a reaction medium in the presence of a silver-based catalyst on a substrate, said substrate including a material selected from the group consisting of CeO 2 , basic Al 2 O 3 optionally doped with a calcium or cerium oxide, an amphoteric resin, ZrO 2 , and a mixture of said materials. The invention also relates to the use of a silver-based catalyst on a substrate that can be used in said method.

First claim

The invention claimed is:

1. A process for the synthesis of glycolic acid or one of its salts comprising the following step:
bringing glycerol and an oxidizing agent into contact in a reaction medium in the presence of a catalyst based on silver on a support, said support comprising a material chosen from the group consisting of CeO 2 , basic Al 2 O 3 , optionally doped with a calcium or cerium oxide, an amphoteric resin, ZrO 2 and a mixture of these materials;
wherein a base which produces hydroxide ions is present in the reaction medium; and
wherein the molar ratio of hydroxide ions to glycerol [OH]/[gly] brought together is from 0.5 to 1.2.

2. The process as claimed in claim 1 , wherein said catalyst is a catalyst on a support of formula Ag/CeO 2 , basic Ag/Al 2 O 3 , optionally doped with calcium oxide or with cerium oxide, or Ag/IR45.

3. The process as claimed in claim 1 , wherein the catalyst comprises, as metal entity, only silver.

4. The process as claimed in claim 1 , wherein the pH of the reaction medium is greater than or equal to 8.

5. The process as claimed in claim 1 , wherein which said oxidizing agent is oxygen.

6. The process as claimed in claim 1 , wherein which the temperature of the reaction medium is chosen within a range extending from 50 to 150° C.

7. The process as claimed in claim 1 , wherein the catalyst based on silver on a support is a catalyst, the proportion by weight of silver with respect to the support of which varies from 10 to 0.2%.

8. The process as claimed in claim 1 , wherein the glycerol/catalyst ratio by weight in the reaction medium is chosen within a range extending from 2 to 100.

9. The process as claimed in claim 1 , wherein the glycerol is of vegetable origin.

10. The process as claimed in claim 1 , wherein the amounts of calcium or cerium oxides optionally used are less than 3 mmol of the atom used with respect to 1 g of support.

Assignees

• Skrzynska Elzbieta
• Dumeignil Franck
• Capron Mickaël
• Duhamel Louise
• Pivert
• Centre Nat De La Rech Scient (Cnrs)
• Université Des Sciences Et Tech De Lille 1

Inventors

• Skrzynska Elzbieta
• Dumeignil Franck
• Capron Mickaël
• Duhamel Louise

Classifications

• C07C51/23

  of oxygen-containing groups to carboxyl groups · CPC title

• C07C51/235 Primary

  of —CHO groups or primary alcohol groups · CPC title

• B01J37/035

  Precipitation on carriers · CPC title

• B01J23/50

  Silver · CPC title

• C07C59/06

  Glycolic acid · CPC title