Purification of cadaverine using high boiling point solvent
One aspect of the invention relates to a method for the purification of cadaverine from an aqueous cadaverine composition comprising one or more involatile impurities, the method comprising obtaining cadaverine from evaporation or distillation of the aqueous cadaverine composition wherein one or more solvents are added to the evaporation/distillation system before the evaporation/distillation starts, during the evaporation/distillation and/or after the evaporation/distillation substantially stops when no more evaporation/distillation is observed; wherein the one or more solvents comprise at least one or more high boiling point (HBP) solvents. In certain embodiments, cadaverine may be evaporated/distilled at an unexpectedly lower heating temperature for an unexpectedly shorter heating time to provide a desired yield. Because cadaverine may decompose at high temperature, the unexpectedly lower heating temperature and unexpectedly shorter heating time decrease the undesired cadaverine decomposition. The methods disclosed herein provides unexpected high recovery rate (˜100%) in the evaporation/distillation of cadaverine at a larger scale at a lower heating temperature compared to conventional distillation methods. Thus, the method disclosed herein will be highly appreciated in the industrial production of cadaverine.
1. A method for the purification of cadaverine from an aqueous cadaverine composition comprising one or more involatile impurities, the method comprising:
a) distilling or evaporating the aqueous cadaverine composition wherein one or more solvents are added to the evaporation/distillation system before the evaporation/distillation starts, during the evaporation/distillation and/or after the evaporation/distillation substantially stops when no more evaporation/distillation is observed to produce purified cadaverine; wherein
the evaporation or distillation is done at a heating temperature of about 80° C. to about 180° C., and the evaporation or distillation is subjected to a pressure of 1 atm or lower; and
the one or more solvents comprise at least one or more high boiling point (HBP) solvents having a boiling point of at least about 185° C. (1 atm).
2. The method of claim 1 , wherein the aqueous cadaverine composition is obtained from the following steps:
a0-1) providing an aqueous cadaverine salt composition;
a0-0) optionally adding one or more high boiling point solvents; and
a1) adjusting the pH of the aqueous cadaverine salt composition to provide an aqueous cadaverine composition having a pH of at least about 12.
3. The method of claim 1 , wherein the aqueous cadaverine composition is obtained from the following steps:
a0-2) providing an aqueous cadaverine salt composition comprising a cadaverine production composition, wherein the cadaverine production composition is obtained from a bio-based cadaverine production process;
a0-0) optionally adding one or more high boiling point solvents; and
a1) adjusting the pH of the aqueous cadaverine salt composition to provide an aqueous cadaverine composition having a pH of at least about 12.
4. The method of claim 2 , wherein Step a1) further comprises:
a1-1) Removing a solid composition from the aqueous cadaverine composition of step a1).
5. The method of claim 4 , wherein step a1-1) further comprises the following steps before step a1-1) is performed:
a1-11) concentrating the aqueous cadaverine salt composition before the addition of the one or more bases; and/or optionally
a1-12) concentrating the aqueous cadaverine salt composition/base reaction after the addition of the one or more bases; and/or optionally
a1-13) concentrating the aqueous cadaverine salt composition/base reaction during the addition of the one or more bases.
6. The method of claim 1 , wherein the cadaverine concentration of the aqueous cadaverine composition of step a) is about 5% or higher.
7. The method of claim 1 , wherein the cadaverine concentration of the aqueous cadaverine composition of step a) is about 20% or higher.
8. The method of claim 4 , wherein step a1-1) disclosed herein comprises:
a1-31) filtering/centrifuging the first composition to provide a solid and a filtrate/supernatant;
a1-32) rinsing the solid with an aqueous salt solution and filtering/centrifuging the obtained mixture to provide another solid and another filtrate/supernatant;
a1-33) optionally repeating step a1-32) until the solid obtained is substantially free of cadaverine; and
a1-34) combining the filtrates/supernatants obtained from steps a1-31), a1-32) and a1-33) to provide the aqueous cadaverine composition to be further processed in step a).
9. The method of claim 2 , wherein the acid anion content of the aqueous cadaverine composition is no more than about 50% of that of the aqueous cadaverine salt composition.
10. The method of claim 2 , wherein the acid anion content of the aqueous cadaverine composition is no more than about 70% of that of the aqueous cadaverine salt composition.
11. The method of claim 2 , wherein the aqueous cadaverine salt composition comprises one or more cadaverine salts selected from the group consisting of cadaverine sulfate, cadaverine chloride, cadaverine carbonate, cadaverine phosphate and any combinations thereof.
12. The method of claim 2 , wherein the aqueous cadaverine salt composition has a pH of about 11 or lower.
13. The method of claim 2 , wherein the pH of the first composition of step a1) is about 13.5 or higher.
14. The method of claim 2 , wherein step a1) comprises adding an inorganic base composition into the aqueous cadaverine salt composition, wherein the inorganic base composition comprises one or more inorganic bases selected from the group consisting of alkaline metal hydroxides, alkaline earth metal hydroxides, and basic salts thereof.
15. The method of claim 14 , wherein the one or more inorganic bases are selected from the group consisting of NaOH, KOH, Na 3 PO 4 , Na 2 CO 3 , and any combinations thereof.
16. The method of claim 1 , wherein the aqueous cadaverine composition is distilled at a reduced pressure or ambient pressure in step a).
17. The method of claim 1 , wherein the one or more HBP solvents have one or more boiling points of at least about 190° C. (1 atm).
18. The method of claim 1 , wherein the one or more HBP solvents are selected from the group consisting of alkanes, chloroalkanes, benzene derivatives, alcohols, ethers, amines, esters, nitriles, and any combinations thereof.
19. The method of claim 18 , wherein the one or more HBP solvents are selected from the group consisting of C 14 alkanes, C 11 /C 14 alkane mixture, biphenyl ether, and dodecanol.
20. The method of claim 18 , wherein the one or more HBP solvents are alkanes.
21. The method of claim 18 , wherein the one or more HBP solvents do not comprise alcohol.
22. The method of claim 1 , wherein the purified cadaverine is produced with a recovery yield of at least 66.5%.