Methods for producing 5-(halomethyl)furfural
The present disclosure provides methods to produce 5-(halomethyl)furfural, including 5-(chloromethyl)furfural, by acid-catalyzed conversion of C6 saccharides, including isomers thereof, polymers thereof, and certain derivatives thereof. The methods make use of acids with lower concentrations, and allows for conversion of sugars into 5-(halomethyl)furfural at higher temperatures and faster reaction or residence times.
1. A method for producing 5-(halomethyl)furfural, comprising:
a) combining a feedstock, an acid, and a salt in a reaction vessel to form a reaction mixture, wherein:
the feedstock comprises one or more C6 monosaccharides, disaccharides comprising monomeric units having six carbon atoms, or polysaccharides comprising monomeric units having six carbon atoms:
the acid is HX, wherein X is halo;
the salt is A r+ (X − ) r , wherein:
A r+ is a Group I or Group II cation, and
X − is a halo anion; and
the reaction mixture has a [H + ] less than or equal to 8 M and a [X − ] of at least 8 M; and
b) producing 5-(halomethyl)furfural from at least a portion of the feedstock in the reaction mixture.
2. The method of claim 1 , wherein X is chloro.
3. The method of claim 1 , wherein the acid is added continuously.
4. The method of claim 1 , wherein A r+ is Li + , Na + , K + , Rb + , Cs + , Mg 2+ , Ca 2+ , or Sr 2+ .
5. The method of claim 4 , wherein A r+ is Li + .
6. The method of claim 4 , wherein A r+ is Ca 2+ .
7. The method of claim 1 , wherein the reaction mixture has a [H + ] less than or equal to 5 M.
8. The method of claim 1 , wherein the reaction mixture has a [X − ]of at least 9 M.
9. The method of claim 1 , wherein the reaction mixture has:
a [H + ] less than or equal to 5 M: and
a [X − ] of at least 9 M.
10. The method of claim 1 , wherein the reaction mixture has:
a [H + ] less than or equal to 2 M; and
a [X − ] of at least 10 M.
11. The method of claim 1 , wherein the 5-(halomethyl)furfural is produced at a temperature of at least 115° C.
12. The method of claim 11 , wherein the reaction mixture has a [H + ] less than or equal to 0.6 M.
13. The method of claim 1 , wherein the feedstock and the [H + ] is present in the reaction mixture at a molar ratio of 1 : 1.
14. The method of claim 1 , wherein the reaction mixture has a [H + ] between the feedstock concentration and 5 M.
15. The method of claim 1 , wherein:
the reaction mixture has a [H + ] between the feedstock concentration and 2 M; and
the 5-(halomethyl)furfural is produced at a temperature of at least 135° C.
16. The method of claim 1 , wherein the reaction mixture has a [H + ] between 0.1 times the feedstock concentration and 5M.
17. The method of claim 1 , wherein the feedstock, the acid and the salt are further combined with a solvent system, wherein the solvent system comprises one or more alkyl phenyl solvents, one or more heavy alkane solvents, one or more ester solvents, one or more aromatic solvents, one or more silicone oils, or any combinations or mixtures thereof.
18. The method of claim 1 , wherein the feedstock is selected from the group consisting of corn stover, corn cob, corn kernel, rice flour, whole cane, beet pulp, beet processing raffinate, empty palm fruit bunches, palm fronds, saw dust, wood pellets, rice hulls, peanut hulls, spent grains, paper sludge, cardboard, old corrugated containers (OCC), old newspaper (ONP), mixed paper, wheat straw, paper mill effluent, newsprint, municipal solid wastes, wood chips forest thinnings slash miscanthus, switchgrass, sorghum, bagasse manure, wastewater biosolids, green waste, and food or feed processing residues, or any combinations thereof.
19. The method of claim 1 , wherein:
(i) the acid is produced in situ; or
(ii) the salt is produced in situ; or
(ii) both (i) and (ii).
20. The method of claim 1 , wherein the reaction mixture has a [H + ] of less than or equal to 2 M.
21. The method of claim 1 , wherein the reaction mixture has a [H + ] greater than or equal to 0.0001 M and less than or equal to 8 M.
22. The method of claim 1 , wherein the reaction mixture has a [H + ] between 0.25 M and 8 M.
23. The method of claim 1 , wherein the reaction mixture has a [H + ] between 0.5 M and 8 M.
24. The method of claim 1 , wherein the reaction mixture has a [H + ] between 1 M and 8 M.
25. The method of claim 1 , wherein the reaction mixture has a [H + ] between 0.25 M and 5 M.
26. The method of claim 1 , wherein the reaction mixture has a [H + ] between 0.5 M and 5 M.
27. The method of claim 1 , reaction mixture has a [H + ] between 1 M and 5 M.
28. The method of claim 1 , wherein the reaction mixture has a [H + ] between 0.25 M and 2 M.
29. The method of claim 1 , wherein the reaction mixture has a [H + ] between 0.5 M and 2 M.
30. The method of claim 1 , reaction mixture has a [X − ]of between 8 M and 15 M.
31. The method of claim 1 , wherein the feedstock, the acid and the salt are further combined with a solvent system, wherein the solvent system comprises one or more linear alkyl benzenes.
32. The method of claim 1 , wherein the feedstock, the acid and the salt are further combined with a solvent system, wherein the solvent system comprises para-xylene, mesitylene, naphthalene, anthracene, toluene, dodecylbenzene, pentylbenzene, hexylbenzene, sulfolane, hexadecane, heptadecane, octadecane, icosane, heneicosane, docosane, tricosane, tetracosane, or any combinations or mixtures thereof.
33. The method of claim 1 , wherein the feedstock, the acid and the salt are further combined with a solvent system, wherein the solvent system comprises one or more phenyl ether solvents.
34. The method of claim 1 , wherein the feedstock comprises cellulose, glucose, fructose, or any combinations thereof.
35. The method of claim 1 , wherein X is bromo.