DISTILLATION PROCESS FOR PRODUCTION OF ACRYLIC ACID

• US 20180022677A1
• Filed: 02/12/2016
• Published: 01/25/2018
• Est. Priority Date: 02/13/2015
• Status: Active Grant

• Current Assignee: Novomer, Inc (Danimer Scientific, Inc.)
• Original Assignee: Novorner Incorporated
• Inventors: SOOKRAJ, Sadesh H.
• Granted Patent: US 10,099,989 B2
• Time in Patent Office: Days
• CPC Class Codes: B01J 19/2435 Loop-type reactors
• CPC Class Codes: B01J 2219/24 Stationary reactors without moving elements inside
• CPC Class Codes: C07C 51/09 from carboxylic acid esters or lactones
• CPC Class Codes: C07C 51/44 by distillation
• CPC Class Codes: C07C 57/04 Acrylic acid; Methacrylic acid
• CPC Class Codes: C08G 63/08 Lactones or lactides
• CPC Class Codes: C08G 63/823 for the preparation of polylactones or polylactides
• CPC Class Codes: Y02P 20/10 Process efficiency

Abstract

Provided are integrated processes for the conversion of beta propiolactone to acrylic acid. Systems for the production of acrylic acid are also provided.

Claims

1. A method for producing acrylic acid, comprising:

(a) providing a feedstock stream comprising beta propiolactone and a solvent;

(b) directing the feedstock stream to a reaction zone, wherein the feedstock stream is contacted with a polymerization catalyst and wherein at least a portion of the beta propiolactone is converted to poly(propiolactone);

(c) maintaining the reaction zone at a temperature at or above the pyrolysis temperature of poly(propiolactone);

(d) thermal decomposing the poly(propiolactone) in the reaction zone to produce acrylic acid;

(e) withdrawing a distillation stream of the solvent from the reaction zone; and

(f) withdrawing an acrylic acid product stream from the reaction zone;

wherein steps (b) to (d) occur in the same reaction zone.

2. The method of claim 1, wherein the solvent has a boiling point below 160°

C.

3. The method of claim 1, wherein the solvent is tetrahydrofuran.

4. The method of claim 1, further comprising providing a second solvent and directing a second solvent stream to the reaction zone.

5. The method of claim 4, wherein the second solvent stream comprises the second solvent and the polymerization catalyst.

6. The method of claim 4, further comprising withdrawing a distillation stream of the second solvent from the reaction zone.

7. The method of claim 1, further comprising directing the distillation stream of the first solvent to a carbonylation reactor used to provide the beta propiolactone.

8. The method of claim 1, further comprising withdrawing a recycling stream of the polymerization catalyst from the reaction zone.

9. The method of claim 1, wherein the polymerization catalyst is a salt of a compound of formula:

10. The method of claim 1, wherein the polymerization catalyst is a salt of a compound of formula:

11. The method of claim 1, wherein the polymerization catalyst is a heterogenous catalyst.

12. The method of claim 11, wherein the polymerization catalyst is provided as a fixed bed of polymerization catalyst.

13. The method of claim 1, further comprising withdrawing a distillation stream of the second solvent.

14. The method of claim 1, wherein heat is generated in the reaction zone, and the method further comprises capturing at least a portion of the heat generated and directing the captured heat to other processes.

15. The method of claim 14, wherein the captured heat is directed to a carbonylation reaction used to provide the beta propiolactone.

16. The method of claim 1, further comprising using low grade heat to maintain temperature of the acrylic acid product stream above its boiling point.

17. A system for converting beta propiolactone to acrylic acid, comprising:

(a) beta propiolactone (BPL) in a solvent;

(b) a polymerization catalyst,

wherein at or above the pyrolysis temperature of poly(propiolactone) (PPL), BPL begins polymerizing to PPL in the presence of the polymerization catalyst, which PPL concurrently thermally decomposes to acrylic acid, and wherein acrylic acid formed in situ maintains the reaction polymerizing BPL to PPL; and

(c) a distillation stream of the solvent.

18. A system for converting beta propiolactone to acrylic acid, comprising:

(a) a reaction zone comprising beta propiolactone (BPL), a solvent, and a polymerization catalyst;

wherein at or above the pyrolysis temperature of poly(propiolactone) (PPL), BPL begins polymerizing to PPL in the presence of the polymerization catalyst, which PPL concurrently thermally decomposes to acrylic acid;

(b) a distillation stream of the solvent; and

(c) a return loop for providing acrylic acid to the reaction zone.