Distillation process for production of acrylic acid

1. A method for producing acrylic acid, comprising:

(a) filtering a solvent stream and a beta propiolactone stream through a membrane;

(b) contacting the solvent stream and the beta propiolactone stream in a first reaction zone in a presence of a polymerization catalyst;

(c) polymerizing a poly(propiolactone) from the beta propiolactone stream, the solvent stream, and the polymerization catalyst in a second reaction zone;

(d) decomposing, by thermolysis, the poly(propiolactone) into acrylic acid in the reaction zone; and

(e) distilling a distillation stream, comprising the solvent steam, and a product stream, comprising the acrylic acid, from the reaction zone.

2. The method of claim 1 , wherein the polymerization catalyst is a homogeneous catalyst, and wherein the solvent stream comprises the polymerization catalyst.

3. The method of claim 2 , further comprising:

withdrawing a recycle stream comprising the polymerization catalyst so that the polymerization catalyst can be reused in the reaction zone.

4. The method of claim 1 , wherein the beta propiolactone stream further comprises another solvent, and wherein the method further comprises:

distilling a recycle stream comprising the solvent of the beta propiolactone stream; and

directing the recycle stream to a carbonylation reactor that is configured to produce the beta propiolactone stream.

5. The method of claim 4 , wherein the solvent of the beta propiolactone stream is a non-protic solvent, a hydrocarbon, or an ether, and wherein the solvent of the beta propiolactone stream is usable in carbonylation of beta propiolactone.

6. The method of claim 1 , further comprising:

directing the distillation stream to a recycling tank so that the solvent of the solvent stream is reusable in the reaction zone.

7. The method of claim 1 , wherein the solvent of the solvent stream is a non-protic polar solvent, and wherein the poly(propiolactone) is soluble in the solvent of the solvent stream.

8. The method of claim 1 , wherein the polymerization catalyst is a carboxylate salt of a cation, wherein the cation includes a positive charge that is on a metal, metal oxide, salts of alkali and alkaline earth metals, borates, silicates, or salts of other metals.

9. The method of claim 1 , wherein the polymerization catalyst is a heterogeneous catalyst and the polymerization catalyst has a form of a fixed or packed bed.

10. The method of claim 1 , wherein the product stream has an acrylic acid content of at least about 99.5%.

11. A system, comprising:

(a) a membrane that is configured to filter a beta propiolactone stream and a solvent stream; and

(b) a reaction zone downstream of the membrane, the reaction zone is a single distillation column and is configured to:

(i) receive the beta propiolactone stream and the solvent stream;

(ii) concurrently polymerize beta propiolactone of the beta propiolactone stream to poly(propiolactone) in a presence of a polymerization catalyst and thermally decompose the poly(propiolactone) to acrylic acid; and

(iii) output a distillation stream, comprising a solvent of the solvent stream, and a product stream, comprising the acrylic acid; and

wherein the polymerization catalyst is a homogeneous catalyst, and wherein the solvent stream comprises the polymerization catalyst.

12. The system of claim 11 , wherein the reaction zone is configured to output a recycle stream, and wherein the recycle stream comprises the polymerization catalyst.

13. The system of claim 11 , wherein the beta propiolactone stream further comprises another solvent, and wherein the reaction zone is configured to output a recycle stream comprising the solvent of the beta propiolactone stream.

14. The system of claim 13 , wherein the solvent of the beta propiolactone stream is a non-protic polar solvent, and wherein the solvent of the beta propiolactone is recyclable in a carbonylation reactor that is upstream of a reactor zone.

15. A system, comprising:

(a) a membrane that is configured to filter a beta propiolactone stream and a solvent stream; and

(b) a reaction zone downstream of the membrane, the reaction zone is a single distillation column and is configured to:

(i) receive the beta propiolactone stream and the solvent stream;

(ii) concurrently polymerize beta propiolactone of the beta propiolactone stream to poly(propiolactone) in a presence of a polymerization catalyst and thermally decompose the poly(propiolactone) to acrylic acid; and

(iii) output a distillation stream, comprising a solvent of the solvent stream, and a product stream, comprising the acrylic acid;

wherein the polymerization catalyst is a heterogeneous catalyst, and wherein the polymerization catalyst has a form of a fixed or packed bed.

16. The system of claim 11 , wherein the solvent of the solvent stream is a non-protic polar solvent, and wherein the poly(propiolactone) is soluble in the solvent of the solvent stream.

17. The system of claim 11 , wherein the product stream has an acrylic acid content of at least about 99.5%.

18. The system of claim 11 , wherein the polymerization catalyst is a carboxylate salt of a cation, wherein the cation includes a positive charge that is on a nitrogen atom, a sulfur atom, a phosphorus atom, or any combination thereof.

19. The system of claim 18 , wherein the polymerization catalyst is a carboxylate salt of a protonated amine, a quaternary ammonium, guanidinium, sulfonium, arsonium, a substituted nitrogen-containing heterocycle cation, a phosphorus cation, or any combination thereof.

20. The system of claim 15 , wherein the polymerization catalyst is a carboxylate salt of a cation, wherein the cation includes a positive charge that is on a nitrogen atom, a sulfur atom, a phosphorus atom, or any combination thereof, and the polymerization catalyst is a carboxylate salt of a protonated amine, a quaternary ammonium, guanidinium, sulfonium, arsonium, a substituted nitrogen-containing heterocycle cation, a phosphorus cation, or any combination thereof.