Method of forming a dry quaternary ammonium salt mixture
View Patent ↗Disclosed herein is a method comprising: (a) adding an aqueous solution comprising a quaternary ammonium salt to an organic solvent in a vessel under an inert atmosphere, thereby forming a first mixture comprising the quaternary ammonium salt and the solvent; and (b) mixing the first mixture at a temperature and for a time sufficient to remove water and a portion of the solvent from the first mixture, wherein the mixing is performed in an inert atmosphere and the temperature is less than the decomposition temperature of the quaternary ammonium salt.
1. A method of forming quaternary ammonium salt mixture, comprising:
(a) adding an aqueous solution comprising a quaternary ammonium salt to an organic solvent in a vessel under an inert atmosphere, thereby forming a first mixture comprising the quaternary ammonium salt and the solvent; and
(b) mixing the first mixture at a temperature and for a time sufficient to remove water and a portion of the solvent from the first mixture,
wherein the mixing is performed in an inert atmosphere and the temperature is less than the decomposition temperature of the quaternary ammonium salt, and
wherein the quaternary ammonium salt is selected from the group consisting of guanidinium salts, bis-guanidinium alkane salts, dialkylaminopyridinium salts, bis-dialkylaminopyridinium salts, dialkylpiperidinium salts, bis-alkyl quaternary ammonium salts, and combinations of two or more of the foregoing.
2. The method of claim 1 , wherein the aqueous solution further comprises an inorganic salt and the method further comprises precipitating the inorganic salt from the first mixture and removing the precipitated inorganic salt from the first mixture, thereby forming a second mixture.
3. The method of claim 2 , wherein removing the precipitated inorganic salt comprises filtering.
4. The method of claim 2 , wherein the second mixture contains less than 50 parts per million of water.
5. The method of claim 2 , wherein the second mixture contains less than 25 parts per million of water.
6. The method of claim 2 , wherein the method further comprises adding a drying agent to the second mixture.
7. The method of claim 2 , wherein the method further comprises combining the second mixture with an additional compound, thereby forming a third mixture, and drying the third mixture to remove trace water.
8. The method of claim 1 , wherein the aqueous solution further comprises an inorganic salt and the method further comprises agglomerating the inorganic salt.
9. The method of claim 1 , wherein the quaternary ammonium salt has formula (II):
wherein R 7 and R 8 are hydrocarbyl groups having 1 to 13 carbons, R 9 is a linear or branched alkyl group having 4 to 12 carbons, and X − is the anion of a strong acid.
10. The method of claim 1 , wherein the quaternary ammonium salt is hexaethylguanidinium chloride.
11. The method of claim 1 , wherein the temperature is 70° C. to 230° C.
12. The method of claim 1 , wherein adding is performed at a pressure of 50 millimeters of mercury to 300 millimeters of mercury.
13. The method of claim 1 , wherein the mixing is performed at a pressure of 50 millimeters of mercury to 300 millimeters of mercury.
14. The method of claim 1 , wherein the time is 1 minute to 24 hours.
15. The method of claim 1 , wherein the solvent is selected from the group consisting of halogenated aromatics, alkylated aromatics, ether aromatics, and combinations thereof.
16. The method of claim 15 , wherein the solvent is an aromatic organic solvent selected from the group consisting of orthodichlorobenzene, veratroles, anisoles, toluenes, xylenes, chlorobenzenes, benzenes, and combinations of two or more of the foregoing.
17. The method of claim 1 , wherein the quaternary ammonium salt is selected from the group consisting of halide salts, nitrate salts, nitrite salts, boron-containing salts, antimony-containing salts, phosphate salts, carbonate salt, carboxylate salt, and combinations of two or more of the foregoing.
18. The method of claim 1 , wherein the aqueous solution is added to the solvent incrementally.
19. The method of claim 1 , wherein the aqueous solution is added to the solvent continuously.
20. The method of claim 1 , wherein the solvent is heated prior to adding the aqueous solution.
21. The method of claim 1 , wherein the solvent is heated to a temperature of 70° C. to 230° C. prior to adding the aqueous solution.
22. The method of claim 1 , wherein less than 10 weight percent of the quaternary ammonium salt, based on the total initial weight of the quaternary ammonium salt is decomposed during the method.
23. The method of claim 1 , wherein the inert atmosphere is nitrogen and the nitrogen flows into the vessel at a rate sufficient to facilitate removal of the water.
24. The method of claim 1 , wherein the method further comprises condensing the removed solvent, removing water from the condensed solvent and recycling the dried condensed solvent.
25. The method of claim 24 , wherein the method further comprises condensing organic solvent with a first condenser and condensing water in a gaseous phase in a second condenser.
26. The method of claim 1 , wherein the quaternary ammonium salt has formula (VI):
wherein and R 1-5 and R 16 are each independently selected from the group comprising alkyl, cyclo alkyl, aryl, and aryl alkyl and have 1 to 20 carbons and X − is an anion of a strong acid.
27. A method of forming quaternary ammonium salt mixture, comprising:
(a) combining an aqueous solution comprising a quaternary ammonium salt and an inorganic salt with an aliphatic chlorinated solvent, thereby forming a first phase comprising water and inorganic salt and a second phase comprising chlorinated aliphatic solvent, trace water and the quaternary ammonium salt;
(b) separating the first phase from the second phase;
(c) adding the second phase to an organic solvent in a vessel under an inert atmosphere, thereby forming a first mixture comprising the quaternary ammonium salt, trace water, and the solvent; and
(d) mixing the first mixture at a temperature and for a time sufficient to remove water, chlorinated aliphatic solvent and a portion of the solvent from the first mixture,
wherein the mixing is performed in an inert atmosphere and the temperature is less than the decomposition temperature of the quaternary ammonium salt.
28. The method of claim 27 , wherein the chlorinated aliphatic solvent is selected from the group consisting of methylene chloride, chloroethane derivatives, tetrachloro methylene, chloroform, and combinations of two or more of the foregoing.
29. The method of claim 1 , wherein the first mixture comprises an inorganic salt in an amount of 0.1 to 20 weight percent.
30. The method of claim 29 , wherein the mixture is further mixed for a time and at a temperature sufficient to remove trace water to result in a mixture having less than or equal to 50 ppm water.
31. The method of claim 30 , wherein the mixture is further mixed for a time and at a temperature sufficient to remove trace water to result in a mixture having less than or equal to 25 ppm water.
32. The method of claim 1 , wherein the method further comprises combining the second mixture with an additional compound, thereby forming a third mixture, and drying the third mixture to remove trace water.