Process for the extraction of polyhydroxyalkanoates from biomass
View Patent ↗The invention relates to processes for extracting polyhydroxyalkanoate from a biomass, comprising admixing the biomass with an organic solvent for from 1 second to 15 minutes at a first temperature of from 5° C. below the melting point of the polyhydroxyalkanoate to 10° C. above the melting point of the polyhydroxyalkanoate and at a pressure of from 1 bar to 10 bar to provide a composition comprising the organic solvent and polyhydroxyalkanoate.
1. A process for extracting polyhydroxyalkanoate from a biomass, comprising:
admixing the biomass with an organic solvent for from about 1 second to about 15 minutes at a temperature of from about 5° C. below the melting point of the polyhydroxyalkanoate to about 10° C. above the melting point of the polyhydroxyalkanoate and at a pressure of from about 1 bar to about 10 bar to provide a composition comprising the organic solvent and polyhydroxyalkanoate.
2. The process of claim 1 , further comprising maintaining the composition within a temperature range, which is from ambient temperature to the melting point of the polyhydroxyalkanoate.
3. The process of claim 2 , further comprising admixing the composition with additional organic solvent.
4. The process of claim 2 , wherein the maintaining occurs for from 5 to 120 minutes.
5. The process of claim 2 , wherein the temperature range is from 80° C. to 130° C.
6. The process of claim 2 , further comprising separating the polyhydroxyalkanoate from the organic solvent subsequent to the maintaining.
7. The process of claim 6 , wherein the separating comprises precipitating the polyhydroxyalkanoate from the organic solvent to form precipitated polyhydroxyalkanoate.
8. The process of claim 7 , further comprising isolating the precipitated polyhydroxyalkanoate.
9. The process of claim 1 , wherein the organic solvent is an alcohol, a C 3 –C 7 ketone, or a combination thereof.
10. The process of claim 1 , wherein the organic solvent is methanol, ethanol, propanol, butanol, pentanol, acetone, methyl ethyl ketone, or a combination thereof.
11. The process of claim 1 , wherein the solvent is toluene, ethyl acetate, tetrahydrofuran, acetonitrile, glyme, methyl ester, sulfolane, DMSO, or a combination thereof.
12. The process of claim 1 , wherein the organic solvent is substantially anhydrous.
13. The process of claim 1 , wherein the ratio of organic solvent to polyhydroxyalkanoate is from 5 to 100 parts organic solvent to one part polyhydroxyalkanoate by weight.
14. The process of claim 1 , wherein the ratio of organic solvent to polyhydroxyalkanoate is from 15 parts organic solvent to one part polyhydroxyalkanoate by weight.
15. The process of claim 1 , wherein the first temperature is from 2° C. to 5° C. above the melting point of the polyhydroxyalkanoate.
16. The process of claim 1 , wherein the admixing occurs for from 5 to 15 minutes.
17. The process of claim 2 , wherein the temperature range is from 80° C. to 100° C.
18. The process of claim 1 , wherein the process is a continuous process.
19. The process of claim 2 , further comprising mixing the organic solvent while maintaining it within the temperature range.
20. The process of claim 19 , where the mixing is achieved using a propeller, turbine, screw conveyor, or a combination thereof.
21. The process of claim 2 , wherein the maintaining occurs for 60 minutes.
22. The process of claim 6 , wherein the separating comprises filtering, centrifuging, or a combination thereof.
23. The process of claim 6 , wherein the separating occurs at a temperature, which is from 50° C. to 70° C.
24. The process of claim 7 , wherein the precipitating comprises cooling, flashing, or a combination thereof.
25. The process of claim 7 , wherein the precipitating is achieved by admixing the organic solvent with water or an organic solvent in which polyhydroxyalkanoate is substantially insoluble at a temperature below 50° C.
26. The process of claim 25 , wherein the admixing occurs using a propeller, turbine, high shear, layers of water coated sheets, moving belts, or a combination thereof.
27. The process of claim 1 , wherein the polyhydroxybutyrate is a hydroxybutyrate-hydroxyhexanoate copolymer with a molecular weight of from 100,000 to 1,500,000.
28. The process of claim 1 , further comprising:
a) maintaining the organic solvent for from 5 to 120 minutes at a temperature of from 80° C. to 100° C.;
b) separating the polyhydroxyalkanoate from the organic solvent; and
c) isolating the polyhydroxyalkanoate;
wherein the polyhydroxyalkanoate has a first repeat unit having the structure:
and a second repeat unit having the structure:
wherein each R is independently a C 3 to C 19 alkylene group; and wherein the polyhydroxyalkanoate has from 75 mol % to 99 mol % of the first repeat unit and from 1 mol % to 25 mol % of the second repeat unit.
29. The process of claim 1 or claim 28 , wherein the polyhydroxyalkanoate is a poly(3-hydroxyalkanoate).