Process for the production of furfural
AssigneeE. I. Du Pont de Nemours and Company
InventorsPaul Joseph Fagan, Ronnie Ozer, Eric J. Till
Life of this patent
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Abstract
Furfural is produced by mixing an aqueous feedstock solution containing C5 sugar and/or C6 sugar with a heated, high boiling, water-miscible solvent, such as sulfolane, and a soluble acid catalyst. Furfural product and water are distilled off through a multistage distillation column, leaving non-volatile solvent behind. Typical furfural yields with sulfolane as the reaction solvent are about 80% at as high as 99% conversion. Also, certain by-products (e.g., humins) solubilized in the reaction solvent can be precipitated by addition of water or aqueous feedstock solution and then removed by filtration, thereby providing a convenient and effective way of removing these undesirable byproducts from the reaction mixture.
Claims15
A process comprising:
- (a) providing a reactor comprising a distillation column disposed on top of a reaction vessel, wherein the reaction vessel contains an acid solution comprising a soluble acid catalyst and a water-miscible organic solvent;
- (b) bringing an aqueous feedstock solution into contact with the acid solution in the reaction vessel for a residence time sufficient to produce a mixture of water and furfural, wherein the aqueous feedstock solution comprises C5 sugar, C6 sugar or a mixture thereof, and wherein the contents of the reaction vessel are at a temperature in the range of 100-250° C. and a pressure in the range of 0.0001-0.21 MPa;
- (c) removing the mixture of water and furfural from the top of the distillation column;
- and
- (d) adding water or the aqueous solution to at least a portion of the contents of the reaction vessel comprising organic solvent, acid catalyst, water, unreacted sugars and nonvolatile byproducts to precipitate water-insoluble byproducts and removing the precipitated water-insoluble byproducts.
Dependencies are inferred from the claim text.