Method for preparing levulinic acid and furfural by hydrolyzing biomass

Abstract

The invention discloses a method for preparing levulinic acid and furfural by hydrolyzing biomass. The method comprises the following steps of firstly, mixing the biomass with a catalyst, introducing water vapor to generate primary hydrolysis, discharging a gaseous phase of the primary hydrolysis and condensing to obtain an aqueous solution containing the furfural; secondly, introducing water vapor into the biomass subjected to primary hydrolysis to perform secondary hydrolysis, and discharging a gaseous phase of the secondary hydrolysis; thirdly, performing temperature and pressure reduction on the gaseous phase subjected to the secondary hydrolysis, enabling the gaseous phase to enter into a reaction kettle filled with the biomass, generating primary hydrolysis, discharging the gaseous phase of the primary hydrolysis, and condensing the gaseous phase to obtain an aqueous solution containing the furfural and the levulinic acid; fourthly, supplementing the catalyst into the reaction still in the third step, introducing water vapor for secondary hydrolysis, and discharging a gaseous phase of the secondary hydrolysis; fifthly, repeating the third step and the fourth step; sixthly, purifying and separating the aqueous solution in the first step from the aqueous solution in the third step to obtain the levulinic acid and the furfural. According to the method disclosed by the invention, the yields of the levulinic acid and the furfural are increased; the yield of the furfural reaches 60 percent or above 60 percent, and the yield of the levulinic acid reaches 50 percent or above 50 percent.

Description

technical field [0001] The invention belongs to the technical field of biomass chemical industry, and in particular relates to a method for preparing levulinic acid and furfural by hydrolyzing biomass. Background technique [0002] Levulinic acid (Levulinic Acid, LA), also known as 4-oxovaleric acid, levulonic acid or valeric acid, its appearance is white flake or needle crystal, it is flammable, low toxicity, hygroscopic, when heated No carbon dioxide is released, and distillation under normal pressure hardly decomposes. Since the molecular structure of levulinic acid contains multiple functional groups such as carbonyl, carboxyl, methyl and methylene, it has both the properties of carboxylic acid and the properties of ketone, and has good chemical reactivity, and can undergo esterification and substitution. , condensation and neutralization reactions, etc., and products such as resins, medicines, pesticides, spices, solvents, paints, inks, rubber, plastic additives, lubri...

AI Technical Summary

Problems solved by technology

[0005] In the research on the preparation of levulinic acid by direct hydrolysis of biomass, furfural residue, xylose residue, cottonseed hull, starch, etc. are mostly used as raw materials, and inorganic acid (HCl or H 2 SO 4 ) catalyzed hydrolysis, its disadvantage is that the reaction time is longer, the by-products are more, and the yield is lower

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