Method for continuously producing 5-hydroxymethyl furfural

Abstract

The invention relates to a method for continuously producing 5-hydroxymethyl furfural. The method comprises the following steps: carrying out intra-molecular dehydration reaction on fructose-based carbohydrate in a reactor in a binary two-phase reaction system consisting of a low-boiling point polar organic solvent and an inorganic salt aqueous solution under the catalytic action of a strongly acidic liquid acid catalyst containing a sulfonic acid group; after the reaction is finished, dividing the reaction system into an organic phase and a water phase, and separating the two phases; and discharging the water phase, then returning the water phase to the reactor, and after the organic phase is decolored and purified, obtaining 5-hydroxymethyl furfural. According to the method, the target product can be extracted in-situ to an upper-layer organic phase, and a liquid acid catalyst is retained in a lower-layer inorganic salt aqueous solution, so that the catalyst and the product are separated in-situ. According to the method disclosed by the invention, the organic phase can be adsorbed by adopting activated carbon, the adsorption capacity of the activated carbon is recovered by adopting a high-temperature calcination method, and adsorbed impurities are carbonized into a new carbon material in-situ at high temperature, so that the generation and emission of three wastes are reduced, and the pressure on the environment is relieved.

Description

technical field [0001] The invention relates to a method for efficiently producing 5-hydroxymethylfurfural through fructosyl carbohydrates, and belongs to the field of fine chemical preparation technology. Background technique [0002] Due to the characteristics of renewable and extensive sources of biomass, the research on the synthesis of fuels and fine chemicals using biomass as raw materials is currently an important research route for the transformation of biomass utilization. Among them, sugar compounds are an important part of biomass resources. Starting from sugar compounds, the preparation of new platform compounds by chemical methods is an effective method to solve the current shortage of fossil resources and alleviate the environmental problems caused by the utilization of fossil resources. In recent years, 5-hydroxymethylfurfural (HMF), a product obtained from the dehydration of hexoses, has been considered as an important bio-based furan compound. The compound ...

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Problems solved by technology

Chinese patent CN109879838A discloses a production of HMF in the aqueous phase, and adopts the method of organic solvent extraction for HMF transfer, but because the liquid acid catalyst cannot be separated, although the HMF is extracted into the organic phase, it is still under high temperature and acidic conditions, which is extremely difficult. It is not conducive to the stability of HMF and affects the final yield

Chinese patent CN106810517A discloses a method for continuous synthesis of HMF through continuous extraction, but the generation and extraction of HMF cannot be completed at the same time, the process is complicated, and the liquid acid catalyst cannot be recovered, resulting in waste acid discharge and environmental pollution

However, common liquid acid catalysts have large solubility in water and organic solvents, and it is difficult to separate them from the reaction medium and products.

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