Method for producing 2-furaldehyde
An object of the present invention is to provide a method for suppressing the corrosion of a reactor and reducing waste in the production of 2-furaldehyde from a sugar raw material containing a hexose as a constituent component, and another object of the invention is to provide an industrially advantageous method for producing 2-furaldehyde, which suppresses a decrease in the activity of a catalyst in a case of using an acid catalyst and provides a higher yield. The present invention relates to a method for producing 2-furaldehyde comprising heating a sugar raw material containing a hexose as a constituent component in an aprotic polar solvent in the presence of a solid acid catalyst.
1. A method for producing 2-furaldehyde, comprising heating, in a reaction system, a sugar raw material comprising a hexose as a constituent component in an aprotic polar solvent in the presence of a solid acid catalyst,
wherein the solid acid catalyst is at least one selected from the group consisting of aluminum sulfate, zirconium sulfate, zinc sulfate, nickel sulfate, ferric sulfate, ferrous sulfate, copper sulfate, magnesium sulfate, cobalt sulfate, and a rare earth sulfate; and
the aprotic polar solvent is at least one selected from the group consisting of sulfolane, dimethyl sulfone and phthalide.
2. The method according to claim 1 , further comprising separating the produced 2-furaldehyde from the solvent or byproducts and the solid acid catalyst remaining in the reaction system, while distilling away the produced 2-furaldehyde to the outside of the reaction system.
3. The method according to claim 1 , wherein the solid acid catalyst is a metal sulfate which is not uniformly dissolved in the aprotic polar solvent.
4. The method according to claim 1 , wherein the catalyst is uniformly dissolved or in a uniform liquid prior to reaction, and is in a solid state during the reaction.
5. The method according to claim 1 , wherein the 2-furaldehyde is produced from a hexose component of a sugar raw material comprising a hexose as a constituent component.
6. The method according to claim 1 , wherein the solid acid catalyst is a hydrate.
7. The method according to claim 1 , further comprising supplying water to the reaction system.
8. The method according to claim 1 , further comprising:
collecting the solid acid catalyst with other insoluble components from a reaction mixture after the heating; and then
collecting the solid acid catalyst by dissolving the solid acid catalyst in a solvent to separate the solid acid catalyst from the insoluble components.
9. The method according to claim 8 , wherein the collected solid acid catalyst is recycled into the reaction system.
10. The method according to claim 1 , wherein the 2-furaldehyde is produced without production of hydroxymethylfurfural.
11. The method of claim 1 ,
wherein at least one of the solid acid catalyst, the sugar raw material, and the aprotic polar solvent is separately supplied to the reaction system.