Method for preparing acetylpropionic acid by catalytically converting lignocelluloses

Abstract

The invention discloses a method for preparing acetylpropionic acid by directly catalytically converting lignocelluloses. The method comprises the following steps: hydrolyzing lignocelluloses from various different biological sources directly by one step to obtain foundation platform chemical acetylpropionic acid by adopting an acid ion liquid of a special structure as a catalyst; and uniformly mixing ground biomass lignocellulose powder, the acid ion liquid and proper amount of water according to a certain ratio, heating and reacting under a microwave or non-microwave condition, extracting a reaction liquid by a solvent to obtain acetylpropionic acid, and recycling the ion liquid after being recovered. The mass yield of acetylpropionic acid obtained by the method can exceed 35% compared with that of charged biomass lignocelluloses. According to the method disclosed by the invention, the acid ion liquid replaces traditional inorganic acid catalysts, such as high corrosive sulfuric acid, and even conforms to the environment-friendly chemical requirement; the reaction steps and time are reduced and shortened; the problems of equipment corrosion, acid liquid recycling difficulty and the like are prevented; the catalyst is friendly to environment, and the catalyst can be recycled for multiple times.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis and chemical industry, and relates to a method for preparing levulinic acid by one-step catalytic conversion of lignocellulose. Background technique [0002] The molecular structure of levulinic acid contains a carboxyl group and a ketone group, so it has good reactivity and can synthesize a variety of chemical products through esterification, redox, substitution, polymerization and other reactions. Additives, daily chemicals, lubricants, printing inks, surfactants, synthesis of chiral compounds, electronic materials, optical materials, batteries and other fields have broad application prospects. Compounds that can be derived from levulinic acid include methyltetrahydrofuran (MTHF), 5-aminolevulinic acid (DALA), diphenolic acid (DPA) and the like. Methyl tetrahydrofuran and levulinate can be used as automotive fuel additives. 5-aminolevulinic acid is not only a new generation of photod...

AI Technical Summary

Problems solved by technology

[0005] Although the biomass direct hydrolysis method has a high yield, it uses a large amount of inorganic acid as a catalyst, which is difficult to recover and easily causes environmental pollution. It does not meet the requirements of green chemistry. High requirements for anti-corrosion

Moreover, the whole hydrolysis preparation process needs to be divided into two steps, the reaction time is long, the energy consumption is high, and the economic benefit is poor

Most importantly, the direct biomass hydrolysis method is limited to cellulose as the starting material, and cannot be directly produced from untreated lignocellulose, and the separation of cellulose from lignocellulose is a highly polluting and energy-intensive process. consumption process

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