Process for the preparation of succinic acid ester

Patent metadata

Field	Value
Publication number	US-9527796-B2
Application number	US-201414785113-A
Country	US
Kind code	B2
Filing date	Dec 2, 2014
Priority date	Dec 6, 2013
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A process for the production of dialkyl succinate from a bio-succinic acid feedstock commencing by feeding bio-succinic acid to a reaction distillation column to enable esterification of the succinic acid. The feedstock is passed co-currently with upflowing alkanol such that an esterification reaction occurs. An overhead vapor stream is removed from the reaction distillation column comprising di-ester, alkanol, water of esterification and organic components. The vapor stream is sent to an alkanol separation column where alkanol is separated from the water of esterification and organic components. A side draw is removed from the alkanol separation column comprising partially immiscible organic and aqueous phases. The side draw is passed to a phase separation apparatus where the partially immiscible organic and aqueous phases are separated. The organic phase is passed to a column where the dialkyl succinate is recovered from residual water and other organic components.

First claim

The invention claimed is:

1. A process for the production of dialkyl succinate from a bio-succinic acid feedstock comprising the steps of:
(a) feeding bio-succinic acid to a point at or near the bottom of a reaction distillation zone column operated at temperatures and pressures to enable esterification of the succinic acid and passing said stream co-currently with upflowing alkanol such that said esterification reaction occurs;
(b) removing an overhead vapour stream from at or near the top of the reaction distillation zone column comprising di-ester, alkanol, water of esterification and organic components and passing said stream to an alkanol separation column where the alkanol is separated from the water of esterification and from the organic components;
(c) removing a side draw from the alkanol separation column from a point below the feed point thereto, said side draw comprising partially immiscible organic and aqueous phases;
(d) passing said side draw to phase separation apparatus where the partially immiscible organic and aqueous phases are separated;
(e) passing said organic phase to a column where the dialkyl succinate is separated from residual water and other organic components; and
(f) recovering the dialkyl succinate.

2. A process according to claim 1 wherein the bio-succinic acid is added to a pre-reactor prior to being supplied to the reaction distillation zone column.

3. A process according to claim 2 wherein the pre-reactor is a continuous stirred tank reactor.

4. A process according to claim 2 wherein a product from the pre-reactor is passed to a plug flow reaction vessel before being fed to the reaction distillation zone column.

5. A process according to claim 1 wherein the reaction distillation zone column is operated at an overheads pressure of about 1.3 bara to about 10 bara.

6. A process according to claim 1 wherein reaction distillation zone column operates at a temperature of about 80° C. to about 300° C.

7. A process according to claim 1 wherein the reaction in the reaction distillation zone column is carried out in the absence of a catalyst such that it is auto-catalysed.

8. A process according to claim 1 wherein the reaction in the reaction distillation zone column is carried out in the presence of a catalyst.

9. A process according to claim 8 wherein the catalyst is located in the upper stages of the reaction distillation zone column.

10. A process according to claim 1 wherein the stream removed from at or near the top of the reaction distillation zone column is passed through a condenser before being passed to the alkanol separation column.

11. A process according to claim 1 wherein the stream removed from the reaction distillation zone column is supplied to a central region of the alkanol separation column.

12. A process according to claim 1 wherein the alkanol separated in the alkanol separation column is recycled to the reaction distillation zone column and/or to the pre-reactor where present.

13. A process according to claim 1 wherein the desired di-ester is removed from the alkanol separation column as a side draw.

14. A process according to claim 13 wherein the side draw is removed from the alkanol separation column at a point below the feed point.

15. A process according to claim 1 wherein the phase separation apparatus is a decanter.

16. A process according to claim 1 wherein the aqueous phase from the phase separation apparatus is returned to the alkanol separation column.

17. A process according to claim 16 wherein the returned aqueous phase is returned to a point below the side draw point.

18. A process according to claim 1 wherein the organic phase from the phase separation apparatus is passed to the reaction distillation column.

19. A process according to claim 18 wherein the dialkyl succinate is removed from the reaction distillation column as a side draw.

20. A process according to claim 1 wherein the organic phase from the phase separation apparatus is passed to a dialkyl succinate separation column.

21. A process according to claim 20 wherein the dialkyl succinate separation column is operated at mild vacuum.

22. A process according to claim 20 wherein the dialkyl succinate is removed from the dialkyl succinate separation column as a bottom stream.

23. A process according to claim 20 wherein any water separated in the dialkyl succinate separation column is recycled to the alkanol separation column.

24. A process according to claim 20 wherein any butanol is removed as a liquid draw from the dialkyl succinate separation column.

25. A process according to claim 20 wherein an overhead from the dialkyl succinate separation column and passed to a second phase separation apparatus.

26. A process according to claim 25 wherein the second phase separation apparatus is a decanter.

27. A process according to claim 25 wherein the aqueous phase from the second phase separation apparatus is returned to the alkanol separation column.

28. A process according to claim 22 wherein the organic phase from the second phase separation apparatus is passed to a dialkyl succinate/butanol separation column.

29. A process according to claim 1 wherein a portion of the diester produced in the reaction distillation column zone is removed as a liquid side draw.

Assignees

• Johnson Matthey Davy Technologies Ltd

Inventors

• Smidt Martin Lucas
• Campbell Ian
• Reed Graham
• Gordon Paul
• Ferguson Christopher

Classifications

• C07C67/08 Primary

  by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds · CPC title

• C07C69/40

  Succinic acid esters · CPC title

• B01D3/143

  by two or more of a fractionation, separation or rectification step · CPC title

• B01D17/0208

  by sedimentation · CPC title

• B01D3/009

  in combination with chemical reactions · CPC title