Method for preparing levulinic acid through plant polysaccharide degradation under synergetic catalysis of Lewis acids and Bronsted acid in high-temperature liquid-state water

Abstract

The invention discloses a method for preparing levulinic acid through plant polysaccharide degradation under the synergetic catalysis of Lewis acid and Bronsted acid in high-temperature liquid-state water. According to the invention, water, plant polysaccharide, Lewis acid and Bronsted acid are sequentially added into an autoclave, wherein the mass concentration of plant polysaccharide is 20-200g / L, a molar concentration of Lewis acid is 0.01-0.6mol / L, the molar concentration of Bronsted acid is 0.01-0.6mol / L. The autoclave is sealed, and stirring is carried out; the temperature is increased to 145-210 DEG C, and a reaction is carried out for 1-8h; and cooling is carried out. According to the invention, the raw material is biomass which has rich source and which is renewable. With the synergetic catalysis effect of Lewis acid and Bronsted acid, levulinic acid yield is substantially improved, and reaches a maximal value of 65%. The method has good industrial application prospect.

Description

technical field

[0001] The invention relates to a method for preparing levulinic acid by synergistically catalyzing the degradation of plant polysaccharides with Lewis acid and Bronsted acid in high-temperature liquid water. Background technique

[0002] Plant polysaccharides, also known as plant polysaccharides, are polysaccharides produced by plant cell metabolism with a degree of polymerization of more than 10. Generally, plant polysaccharides are composed of more than 100 or even thousands of monosaccharide groups. Plant polysaccharides are divided into two categories according to their functions in plants: one is to form the support tissue of plants, such as cellulose, which accounts for more than 50% of the carbon content in the plant world, and produces about 150 billion to 200 billion tons of cellulose every year; For the storage of nutrients for plants, monosaccharides can be released after enzymatic hydrolysis to supply energy, such as starch. With the decrease of...

Examples

Embodiment 1

[0031] Add 300mL of deionized water, 6g of cellulose, and 0.29g of hydrochloric acid in sequence in a 500mL autoclave. The mass concentration of cellulose is 20g / L, and the molar concentration of hydrochloric acid is 0.01mol / L. After sealing, stir and heat up to 145°C Reacted for 8 hours; the reaction product was cooled to obtain a reaction liquid, and the reaction liquid was filtered, analyzed by HPLC, and calculated to obtain a molar yield of levulinic acid of 15.6%.

Embodiment 2

[0033] Add 300mL of deionized water, 15g of starch, and 24.53g of zinc chloride successively in a 500mL autoclave. The mass concentration of starch is 50g / L, and the molar concentration of zinc chloride is 0.60mol / L. React at 150°C for 7 hours; the reaction product was cooled to obtain a reaction solution, which was filtered, analyzed by HPLC, and calculated to obtain a molar yield of levulinic acid of 2.8%.

Embodiment 3

[0035] Add 300mL of deionized water, 15g of cellulose, and 17.29g of phosphoric acid in sequence in a 500mL high-pressure reactor. The mass concentration of cellulose is 50g / L, and the molar concentration of phosphoric acid is 0.50mol / L. After sealing, stir and heat up to 160°C Reacted for 5 hours; the reaction product was cooled to obtain a reaction liquid, and the reaction liquid was filtered, analyzed by HPLC, and calculated to obtain a molar yield of levulinic acid of 7.7%.

technical field

[0001] The invention relates to a method for preparing levulinic acid by synergistically catalyzing the degradation of plant polysaccharides with Lewis acid and Bronsted acid in high-temperature liquid water. Background technique

[0002] Plant polysaccharides, also known as plant polysaccharides, are polysaccharides produced by plant cell metabolism with a degree of polymerization of more than 10. Generally, plant polysaccharides are composed of more than 100 or even thousands of monosaccharide groups. Plant polysaccharides are divided into two categories according to their functions in plants: one is to form the support tissue of plants, such as cellulose, which accounts for more than 50% of the carbon content in the plant world, and produces about 150 billion to 200 billion tons of cellulose every year; For the storage of nutrients for plants, monosaccharides can be released after enzymatic hydrolysis to supply energy, such as starch. With the decrease of...

Examples

Embodiment 1

[0031] Add 300mL of deionized water, 6g of cellulose, and 0.29g of hydrochloric acid in sequence in a 500mL autoclave. The mass concentration of cellulose is 20g / L, and the molar concentration of hydrochloric acid is 0.01mol / L. After sealing, stir and heat up to 145°C Reacted for 8 hours; the reaction product was cooled to obtain a reaction liquid, and the reaction liquid was filtered, analyzed by HPLC, and calculated to obtain a molar yield of levulinic acid of 15.6%.

Embodiment 2

[0033] Add 300mL of deionized water, 15g of starch, and 24.53g of zinc chloride successively in a 500mL autoclave. The mass concentration of starch is 50g / L, and the molar concentration of zinc chloride is 0.60mol / L. React at 150°C for 7 hours; the reaction product was cooled to obtain a reaction solution, which was filtered, analyzed by HPLC, and calculated to obtain a molar yield of levulinic acid of 2.8%.

Embodiment 3

[0035] Add 300mL of deionized water, 15g of cellulose, and 17.29g of phosphoric acid in sequence in a 500mL high-pressure reactor. The mass concentration of cellulose is 50g / L, and the molar concentration of phosphoric acid is 0.50mol / L. After sealing, stir and heat up to 160°C Reacted for 5 hours; the reaction product was cooled to obtain a reaction liquid, and the reaction liquid was filtered, analyzed by HPLC, and calculated to obtain a molar yield of levulinic acid of 7.7%.

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