Acid/salt separation

Patent metadata

Field	Value
Publication number	US-9376364-B2
Application number	US-201214238666-A
Country	US
Kind code	B2
Filing date	Aug 16, 2012
Priority date	Aug 16, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

The invention provides a method for preparing a succinic acid, which method includes the steps of: providing magnesium succinate; acidifying the magnesium succinate with hydrochloric acid (HCl), thereby obtaining a solution including succinic acid and magnesium chloride (MgCl 2 ); optionally a concentration step, wherein the solution including succinic acid and MgCl 2 is concentrated; precipitating succinic acid from the solution including succinic acid and MgCl 2 , thereby obtaining a succinic acid precipitate and a MgCl 2 solution. The addition of HCl to a magnesium salt of succinic acid and subsequent precipitation of succinic acid from the solution leads to a very efficient separation of succinic acid from a magnesium succinate solution.

First claim

The invention claimed is:

1. Method for preparing a succinic acid, comprising the steps of
providing magnesium succinate;
acidifying the magnesium succinate with hydrogen chloride (HCl), thereby obtaining a solution comprising succinic acid and magnesium chloride (MgCl 2 );
precipitating succinic acid from the solution comprising succinic acid and MgCl 2 , thereby obtaining a succinic acid precipitate and a MgCl 2 solution; and
subjecting the MgCl 2 solution to a thermal decomposition step at temperatures of at least 300° C., thereby decomposing the MgCl 2 to magnesium oxide (MgO) and HCl.

2. Method according to claim 1 , further comprising
dissolving the HCl formed in the thermal decomposition step in water, thereby obtaining a HCl solution; and
bringing the MgO in contact with water, thereby obtaining magnesium hydroxide (Mg(OH) 2 ).

3. Method according to claim 1 , wherein thermal decomposition is conducted using a spray roaster.

4. Method according to claim 1 , wherein the thermal decomposition is conducted at a pressure of 0.1-10 bar.

5. Method according to claim 1 , wherein the thermal decomposition is conducted at a temperature of 300-450° C.

6. Method according to claim 1 , wherein thermal decomposition is conducted by spraying the MgCl 2 solution into contact with a stream of hot gas.

7. Method according to claim 1 , wherein Mg(OH) 2 is converted to magnesium carbonate (MgCO 3 ), which is then used as a neutralizing agent in a fermentation process.

8. Method according to claim 1 , wherein acidifying the magnesium succinate and precipitating succinic acid thus formed are conducted as one step.

9. Method according to claim 1 , wherein the MgCl 2 solution is subjected to a second precipitation step to recover at least part of the succinic acid remaining in the MgCl 2 solution obtained in the first precipitation step.

10. Method according to claim 9 , wherein the second precipitation is conducted by cooling and/or concentrating the MgCl 2 solution.

11. Method according to claim 9 , wherein additional MgCl 2 is added to the MgCl 2 solution prior to the second precipitation.

12. Method according to claim 1 , comprising a concentration step, wherein the solution comprising succinic acid and MgCl 2 is concentrated to a succinic acid concentration that is equal to the saturation point or up to 5 g/L, lower than the saturation point of succinic acid.

13. Method according to claim 1 , wherein magnesium succinate is acidified with an HCl solution.

14. Method according to claim 1 , wherein magnesium succinate is provided in dissolved form, as part of an aqueous solution or as part of an aqueous suspension obtained in a fermentation process.

15. Method according to claim 14 , wherein the aqueous solution or aqueous suspension comprises at least 10 wt. %, based on the total weight of the solution or suspension and wherein the solution comprising succinic acid and MgCl 2 comprises at least 5 wt. %, based on the total weight of the solution comprising succinic acid.

16. Method according to claim 1 , wherein the magnesium succinate is obtained in a fermentation process, which process comprises a purification step, wherein magnesium succinate is crystallized from the fermentation broth and then optionally dissolved in water to form an aqueous solution.

17. Method according to claim 1 , wherein the magnesium succinate is obtained in a fermentation process in dissolved form, which process comprises a purification step, wherein succinic acid is neutralized by adding a magnesium base, during which step magnesium succinate remains in dissolved form.

Assignees

• De Haan André Banier
• Van Breugel Jan
• Van Der Weide Paulus Loduvicus Johannes
• Jansen Peter Paul
• Vidal Lancis José María
• Cerdà Baró Agustín
• Purac Biochem Bv

Inventors

• De Haan André Banier
• Van Breugel Jan
• Van Der Weide Paulus Loduvicus Johannes
• Jansen Peter Paul
• Vidal Lancis José María
• Cerdà Baró Agustín

Classifications

• C01F5/30

  Chlorides · CPC title

• C07D307/68

  Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen · CPC title

• C01B7/035

  Preparation of hydrogen chloride from chlorides · CPC title

• C01F5/10

  by thermal decomposition of magnesium chloride with water vapour · CPC title

• C07C51/02 Primary

  from salts of carboxylic acids · CPC title