Microbial derived isoprene and methods for making the same

1. A method of purifying isoprene comprising:

a. obtaining a first gaseous composition comprising isoprene and water, wherein the gaseous composition comprises 1 part per million or less of C 2 -C 5 alkyne;

b. flowing the first gaseous composition through a first chiller wherein the first chiller has a temperature of between about 10° C. and about −15° C. thereby resulting in a second gaseous composition and wherein the second gaseous composition comprises less water than the first gaseous composition;

c. flowing the second gaseous composition through a second chiller wherein the second chiller has a temperature below −35° C.; and

d. collecting the resulting liquid isoprene composition.

2. The method of claim 1 , wherein the water is present in the first gaseous composition in an amount that is greater than 70% of its saturation amount.

3. The method of claim 1 , wherein the first gaseous isoprene composition further comprises carbon dioxide in an amount between about 0.1% and about 35% by volume.

4. The method of claim 1 , wherein the first gaseous composition further comprises 1 part per million or less of cyclopentadiene, piperylene and 1,4-pentadiene.

5. The method of claim 1 , wherein the first chiller is cooled using a propylene refrigeration system.

6. The method of claim 1 , wherein the first chiller is cooled using an ammonium refrigeration system.

7. The method of claim 1 , wherein the first gaseous composition is flowed through a drier prior to flowing through the first chiller.

8. The method of claim 1 , wherein the first gaseous composition is flowed through a drier after flowing through the first chiller.

9. The method of claim 1 , wherein the second chiller has a temperature of about −60° C. to about −85° C.

10. The method of claim 1 , wherein the second chiller has a temperature of less than about −65° C.

11. The method of claim 1 , wherein the second chiller is cooled using an ethylene refrigeration system.

12. The method of claim 1 , further comprising nitrogen stripping the liquid isoprene composition.

13. The method of claim 1 , further comprising passing the first gaseous composition through a modified zeolite membrane to separate hydrocarbon impurities from the isoprene.

14. The method of claim 1 , further comprising passing the second gaseous composition through a modified zeolite membrane to separate hydrocarbon impurities from the isoprene.

15. The method of claim 1 , further comprising passing the liquid isoprene composition through a modified zeolite membrane to separate hydrocarbon impurities from the isoprene.

16. A method of purifying isoprene comprising:

a. obtaining a first gaseous composition comprising:

i) isoprene in an amount between about 0.1% and about 15% by volume;

ii) carbon dioxide in an amount between about 0.04% and about 35% by volume;

iii) oxygen in an amount between about 1% and about 20% by volume;

iv) nitrogen in an amount greater than about 50% by volume;

v) argon in an amount less than about 0.9% by volume;

vi) water in an amount greater than about 70% of its saturation amount;

vii) 1 part per million or less of C 2 -C 5 alkyne, cyclopentadiene, piperylene, and 1,4-pentadiene; and

viii) ethanol;

b. flowing the first gaseous composition through a first chiller and an operably connected flash drum, wherein the first chiller has a temperature of between about 10° C. and about −15° C. thereby resulting in a second gaseous composition and wherein the second gaseous composition comprises less water than the first gaseous composition;

c. flowing the second gaseous composition through a second chiller and an operably connected flash drum, wherein the second chiller has a temperature between about −35° C. and about −85° C.; and

d. collecting the resulting liquid isoprene composition.

17. The method of claim 16 , wherein the first gaseous composition is obtained by culturing a plurality of host cells capable of making isoprene.

18. The method of claim 17 , wherein the host cells are yeast.

19. The method of claim 17 , wherein the host cells are Saccharomyces cerevisie .

20. The method of claim 16 , wherein the resulting second gaseous composition comprises less than about 3% by weight of water.

21. The method of claim 16 , wherein the resulting liquid isoprene composition comprises less than about 1% by weight of water.

22. The method of claim 16 , wherein the resulting liquid isoprene composition comprises less than about 1% by weight of carbon dioxide.

23. The method of claim 16 , wherein the resulting liquid isoprene composition comprises less than about 1% by weight of nitrogen.

24. The method of claim 16 , wherein the resulting liquid isoprene composition comprises:

i) at least 65% isoprene by weight; and

ii) less than 1% water by weight.

25. The method of claim 16 , wherein the resulting liquid isoprene composition comprises less than about 1% by weight of ethanol.

26. The method of claim 16 , further comprising nitrogen stripping the liquid isoprene composition.

27. The method of claim 26 , wherein the liquid isoprene composition comprises at least 70% isoprene by weight and less than 1% by weight of dissolved carbon dioxide.

28. The method of claim 26 , wherein the liquid isoprene composition comprises at least 90% isoprene by weight and less than 1% by weight of dissolved carbon dioxide.

29. The method of claim 26 , wherein the liquid isoprene composition comprises at least 95% isoprene by weight and less than 1% by weight of dissolved carbon dioxide.

30. The method of claim 26 , wherein the liquid isoprene composition comprises at least 99% isoprene by weight and less than 0.05% by weight of dissolved carbon dioxide.