HMF production from glucose in ionic liquid media
Methods of converting lignocellulosic derivatives form 5-hydroxymethyl furfural (HMF) in ionic liquids are provided herein. Glucose is enzymatically converted to fructose by isomerization with glucose isomerase and a borate salt. Conversion of fructose to HMF includes dehydration of fructose using ionic liquids or ionic liquids with an acid catalyst to achieve high yield of HMF.
1. A method of processing glucose, the method comprising:
enzymatically converting glucose to fructose to yield a reaction mixture comprising the glucose and the fructose; and
after the enzymatic conversion, converting up to all of the fructose in the reaction mixture to 5-hydroxymethyl furfural by introducing a choline-containing ionic liquid to the reaction mixture.
2. The method of claim 1 , wherein enzymatically converting glucose to fructose further comprises introducing glucose isomerase and a borate salt or boric acid to glucose.
3. The method of claim 2 , wherein the borate salt or boric acid is boric acid.
4. The method of claim 1 , further comprising introducing an acid catalyst.
5. The method of claim 4 , wherein the acid catalyst is selected from the group consisting of aluminum chloride, chromium(III) chloride, tin(IV) chloride, 12-MPA, and 12-TPA.
6. The method of claim 1 , further comprising prior to enzymatically converting the glucose to the fructose, converting cellulose to the glucose via an acidolysis mechanism.
7. The method of claim 1 , wherein the choline-containing ionic liquid is selected from the group consisting of choline acetate and choline salicylate.
8. The method of claim 1 , wherein the glucose is provided in a stirred tank reactor.