Method for preparing 5-hydroxymethyl-furfural by microwave promotion

Abstract

The invention relates to a continuous preparation method for 5-hydroxymethylfurfural (HMF) transformed by a biomass saccharine source under microwave radiation condition by using an ionic liquid as a reaction medium, in particular to a method for continuously preparing and separating HMF. The method comprises the following concrete steps: mixing the ionic liquid and hexose or hexose source biomass as a raw material substrate in a preheating and dissolving system, preheating and dissolving the mixture, feeding the mixture into a microwave reaction system to react for 30 seconds to 30 minutes under the microwave radiation condition so as to efficiently generate the HMF; then feeding the reaction mixture into a depressurizing and distilling system, and distilling the mixture under the condition that an operation temperature is not higher than 180 DEG C to obtain the HMF, wherein the separation yield is as high as 94 percent; and re-feeding the distilled remainder into a preheating system, adding the biomass saccharine source, and then repeating steps of reaction and separation, so as to achieve the aims of recycling of an ionic liquid catalyst system and continuous preparation of the HMF. The method has the advantages of no extra-added catalyst, high HMF selectivity, mild operation condition, quick reaction, reusability of the ionic liquid, low cost, simple process, environmental protection and continuous production, provides a new method for industrialized production of the HMF based on the biomass saccharine source, and opens up a new path for preparing common chemicals in a large scale and replacing fuels.

Description

technical field [0001] The present invention relates to the continuous production of 5-hydroxymethylfurfural (HMF), specifically a kind of biomass sugar source (six-carbon sugar or biomass rich in six-carbon sugar) in ionic liquid under microwave radiation condition It is a process method of continuously and efficiently converting to HMF and recycling the ionic liquid catalytic system. Background technique [0002] 5-Hydroxymethylfurfural is an important fine chemical intermediate and is regarded as a new platform compound based on biomass resources. It is widely used in agricultural chemistry, electrochemistry, cosmetics industry, synthetic pharmaceutical intermediates and other industries. Recently, HMF has been considered as a bridge between carbohydrate resources and the petroleum industry, because 2,5-dimethylfuran (DMF) obtained after selective hydrodeoxygenation of HMF is a high-quality fuel with an energy density higher than that of Ethanol is 40% higher and has lit...

AI Technical Summary

Problems solved by technology

Although the column chromatography method reported in this patent has realized the separation of HMF and ionic liquid and product purification, the column chromatography method involves the use of volatile organic solvents, the separation volume is small, the silica gel usage is large, the separation cost is high, and the reaction The process involves the use of corrosive acid catalysts such as sulfuric acid, hydrochloric acid, etc., which is easy to cause environmental pollution and is not conducive to the industrial production of HMF

[0006] In conclusion, although various methods of converting fructose or other biomass sugar sources to prepare HMF have been reported, there is still a lack of environmentally friendly, efficient, low-cost reaction systems and methods for effective separation and continuous production of HMF.

Images