CLOSED-LOOP PRODUCTION OF FURFURAL FROM BIOMASS Russian patent published in 2020 - IPC C07D307/48 

FIELD: chemistry.

SUBSTANCE: invention relates to a closed method of converting biomass to furfural, wherein said method includes steps of: (a) obtaining material of pentosan-containing biomass; (b) treating a pentosan-containing biomass material in an acid catalysed hydrolysis method in a hydrolysis reactor at a temperature greater than 100 °C for a period of time sufficient to obtain a hydrolysed product stream comprising C₅-carbohydrates and solid substances including cellulose; (c) separating the hydrolysed product stream into a liquid product stream and a solid stream, wherein the liquid product stream comprising carbohydrate compounds, where carbohydrate compounds are at least 50 wt. % C₅-carbohydrate compounds, based on the weight of carbohydrate compounds in the liquid product stream, and a solid product stream comprising solid substances including cellulose; (d) carrying out dehydration reaction C₅-carbohydrates in flow of liquid product in reactor at temperatures in range from 100 °C to 250 °C in the presence of an acid catalyst, and a two-phase mixture comprising an aqueous phase and an organic phase which is immiscible with water, which includes an organic solvent, for a period of time sufficient to obtain furfural or furan derivatives; (e) removing a dehydration product stream from the reactor, comprising water, an organic solvent and furfural, and separating the dehydration product stream into the aqueous recycle stream and the organic product stream comprising furfural; (f) returning the aqueous recycle stream back to the hydrolysis reactor at step (b); and (g) extracting furfural from an organic product stream using at least one extraction process.

EFFECT: technical result is a novel method of producing furfural, which enables to obtain a product with high output.

11 cl, 4 tbl, 8 dwg, 5 ex