阅读说明：本技术 一种碳基固体酸催化琼脂糖制备5-羟甲基糠醛的方法 (Method for preparing 5-hydroxymethylfurfural by catalyzing agarose with carbon-based solid acid ) 是由 李晓云 段冰瑜 梁敏 于 2019-10-11 设计创作，主要内容包括：本发明公开了一种碳基固体酸催化琼脂糖制备5-羟甲基糠醛的方法,属于生物质化工领域。本发明以琼脂糖为原料,采用二甲基亚砜、γ-戊内酯和水混合溶液为反应介质,利用碳基固体酸进行催化反应,经减压过滤后,得到产物5-羟甲基糠醛。该法催化剂酸性强且可循环重复使用,溶剂性质稳定且毒性低,反应过程温和,流程简单,目标产物产率高,环境污染小,应用前景好。(The invention discloses a method for preparing 5-hydroxymethylfurfural by catalyzing agarose with carbon-based solid acid, and belongs to the field of biomass chemical industry. The invention takes agarose as raw material, adopts mixed solution of dimethyl sulfoxide, gamma-valerolactone and water as reaction medium, utilizes carbon-based solid acid to carry out catalytic reaction, and obtains the product 5-hydroxymethylfurfural after decompression and filtration. The method has the advantages of strong acidity of the catalyst, recycling, stable solvent property, low toxicity, mild reaction process, simple flow, high yield of target products, little environmental pollution and good application prospect.)

1. A method for preparing 5-hydroxymethylfurfural by catalyzing agarose with carbon-based solid acid is characterized in that the agarose can be converted into a product 5-hydroxymethylfurfural in a solvent by taking the carbon-based solid acid as a catalyst under a certain temperature condition; the method comprises the following steps:

(1) mixing agarose and carbon-based solid acid, and adding the mixture into a reaction kettle;

(2) adding a certain amount of solvent into a reaction kettle, and reacting at a certain temperature and time;

(3) after the reaction is finished, cooling to 20 ℃, and performing reduced pressure filtration separation to obtain the product 5-hydroxymethylfurfural.

2. The method for preparing 5-hydroxymethylfurfural from carbon-based solid acid-catalyzed agarose according to claim 1, wherein: the agarose used in the step (1) is any one or more of conventional agarose, low-melting-point agarose and high-strength agarose.

3. The carbon-based solid acid catalyzed agarose preparation of 5-A method of hydroxymethylfurfural, characterized by: the carbon-based solid acid in the step (1) is prepared from cellulose, diazobenzenesulfonic acid and gamma-Al₂O₃Under the anaerobic condition, burning for 4h at 800 ℃, and then modifying for 30min by using 2mol/L HCl solution.

4. The method for preparing 5-hydroxymethylfurfural from carbon-based solid acid-catalyzed agarose according to claim 1, wherein: and (2) uniformly mixing the agarose and the carbon-based solid acid in the step (1) according to the mass ratio of 1: 5-15: 1.

5. The method for preparing 5-hydroxymethylfurfural from carbon-based solid acid-catalyzed agarose according to claim 1, wherein: the solvent in the step (2) is a mixed solution of dimethyl sulfoxide, gamma-valerolactone and water according to the proportion of 1: 8: 1 or 2: 6: 2.

6. The method for preparing 5-hydroxymethylfurfural from carbon-based solid acid-catalyzed agarose according to claim 1, wherein: and (3) adding the solution in the step (2) in an amount which is 5-10 times of the sum of the mass of the agarose and the mass of the carbon-based solid acid.

7. The method for preparing 5-hydroxymethylfurfural from carbon-based solid acid-catalyzed agarose according to claim 1, wherein: the reaction temperature in the step (2) is 145-195 ℃.

8. The method for preparing 5-hydroxymethylfurfural from carbon-based solid acid-catalyzed agarose according to claim 1, wherein: the reaction time in the step (2) is 0.5-4 h.

Technical Field

The invention belongs to the field of biomass chemical industry, and relates to a method for preparing 5-hydroxymethylfurfural by catalyzing agarose with carbon-based solid acid.

Background

5-hydroxymethyl furfural (5-hydroxymethyl-2-furfural) is an important chemical raw material and an important platform compound, has aldehyde group and hydroxyl group, so that the compound has good chemical reactivity, can perform chemical reactions such as hydrogenation, oxidation, etherification, esterification and the like to obtain various furan precursors, and can be widely applied to industries such as medicine, fuel, resin plastic synthesis, novel polymer synthesis and the like. The preparation of 5-hydroxymethylfurfural mainly takes C6 carbohydrate (glucose, fructose, sucrose and the like) as a raw material, and the C6 carbohydrate is synthesized by removing trimolecular water or hydrolyzing biomass, and then is converted by dehydration reaction. At present, Lewis acid or salts are commonly used as a catalyst in the production of 5-hydroxymethylfurfural, and although the homogeneous catalyst has a good catalytic effect, the problems of difficult product separation, difficult catalyst recovery, high equipment corrosion resistance requirement, large amount of acid waste liquid generation, environmental pollution and the like exist, so that the large-scale production is limited.

The carbon-based solid acid is a solid catalyst based on a carbon skeleton and containing an acidic functional group such as sulfonic acid, and has high reactivity and can be recycled. Agarose is a linear polymer and is also one of the important forms of biomass resources, and gamma-valerolactone is a green solvent that is miscible with water and many solvents, resins and waxes, promoting the conversion of biomass into platform compounds. The research shows that the agarose is used as a raw material, and the carbon-based solid acid is used for catalyzing and reacting in the gamma-valerolactone-dimethyl sulfoxide-water mixed solution to generate the 5-hydroxymethylfurfural, so that the product yield can be improved, the production of waste acid and waste liquid is less, and the pollution degree to the external environment is small.

Disclosure of Invention

In order to solve the problems, the invention provides a method for preparing 5-hydroxymethylfurfural by catalyzing agarose with carbon-based solid acid, aiming at fully utilizing various biomass resources and efficiently converting the biomass resources into target products under the conditions of low temperature and mild conditions, so that the biomass recycling is realized on one hand, and a technical reference is provided for the industrial production of the 5-hydroxymethylfurfural on the other hand.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a method for preparing 5-hydroxymethylfurfural by catalyzing agarose with carbon-based solid acid is characterized in that the agarose can be converted into a product 5-hydroxymethylfurfural in a solvent by taking the carbon-based solid acid as a catalyst under a certain temperature condition. And comprises the following steps:

(1) mixing agarose and carbon-based solid acid, and adding the mixture into a reaction kettle;

(2) adding a certain amount of solvent into a reaction kettle, and reacting at a certain temperature and time;

(3) after the reaction is finished, cooling to 20 ℃, and performing reduced pressure filtration separation to obtain the product 5-hydroxymethylfurfural.

According to the technical scheme, the agarose used in the step (1) is any one or more of conventional agarose, low-melting-point agarose and high-strength agarose.

According to the technical scheme, the carbon-based solid acid in the step (1) is prepared from cellulose, diazobenzene sulfonic acid and gamma-Al₂O₃In the anaerobic stripBurning for 4h at 800 ℃, and then modifying for 30min by using 2mol/L HCl solution to obtain the product.

According to the technical scheme, the agarose and the carbon-based solid acid in the step (1) are uniformly mixed according to the mass ratio of 1: 5-15: 1.

According to the technical scheme, the solvent in the step (2) is a mixed solution of dimethyl sulfoxide, gamma-valerolactone and water according to the ratio of 1: 8: 1 or 2: 6: 2.

According to the technical scheme, the addition amount of the solution in the step (2) is 5-10 times of the mass sum of the agarose and the carbon-based solid acid.

According to the technical scheme, the reaction temperature in the step (2) is 145-195 ℃.

According to the technical scheme, the reaction time of the step (2) is 0.5-4 h.

Compared with the prior art, the invention has the following remarkable advantages:

the carbon-based solid acid synthesized by the method has the characteristics of strong acidity and cyclic utilization, and can provide a large amount of H for reaction in the catalytic process⁺And the conversion of the reaction from biomass to 5-hydroxymethylfurfural is promoted. The reaction solvent selected by the invention is a mixed solution of dimethyl sulfoxide-gamma-valerolactone and water, has the characteristics of good stability, greenness and low toxicity, and can reduce the product concentration and the generation of byproducts. The invention has the advantages of simple production process flow, mild reaction, high yield of 5-hydroxymethylfurfural and wide application prospect.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the scope of the present invention is not limited to these specific examples.