METHOD FOR PRODUCING FURFURAL FROM BIOMASS Russian patent published in 2020 - IPC C07D307/48 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing furfural from a material of pentosane-containing biomass, which comprises the following steps: (a) obtaining pentosan-containing biomass; (b) contacting said biomass with a solution comprising at least one α-hydroxysulphonic acid, thereby hydrolysing the biomass to obtain a stream of product containing at least one C₅-carbohydrate compound in monomer and/or oligomeric form, and α-hydroxysulphonic acid; (c) selecting at least a portion α-hydroxysulphonic acid from product stream containing at least one C₅carbohydrate compound, to obtain a product stream from which an acid having at least one C₅carbohydrate connection, and recovery α-hydroxysulphonic acid in its component form; (d) recovering a liquid stream comprising said at least one C₅-carbohydrate compound, and wet flow of solid substance containing remaining biomass from product, from which acid is removed; (e) dehydration of C₅-carbohydrate compound in at least a first portion of the liquid stream in the presence of a dehydrating acid, in a two-phase reaction medium comprising an aqueous phase and an organic phase immiscible with water, at a temperature in range of 100 °C to 250 °C; (f) separating a furfural-containing stream of an organic phase and an acid-containing aqueous stream from the dehydration product stream; (g) recycling at least a portion of said aqueous stream or second portion of liquid stream to step (b); (h) separating furfural from an organic phase stream.

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

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