Study On Production Of 5-ethoxymethylfurfural By One-pot Alcoholysis Of Biomass In Two-solvent System

5-Ethoxymethylfurfural(EMF)is a very important biomass fuel and platform compound,and it is recognized as one of the potential alternative fossil energy sources.In the"one-pot method" of biomass for EMF production process,the solvent system affects the conversion of raw materials and the yield of EMF.In the traditional production process,ethanol is both a solvent and a reactant.Adding a solvent to ethanol can effectively increase the conversion of raw materials and the yield of EMF.Therefore,the development of a multi-solvent system biomass one-pot method to prepare EMF technology and technology has become a current research hotspot and difficulty.This paper studies the process conditions and product distribution of fructose,glucose,cellulose in a two-solvent system consisting of tetrahydrofuran,dimethyl sulfoxide,y-valerolactone and ethanol to prepare EMF,using zeolite molecular sieve(USY)and Ultra-low acid(0.1 wt%H2SO4)was used as a catalyst,and the following conclusions were obtained:1.The tetrahydrofuran two-solvent system can effectively improve the conversion rate of fructose and glucose and the yield of EMF.In the two-solvent system of tetrahydrofuran and ethanol,the single factor experiment and response surface experiment of USY catalyzed the preparation of EMF from fructose were carried out,and the optimized reaction conditions were obtained:the reaction temperature was 132 ℃,the reaction time was 31 min,and the substrate concentration was 59 g·L-1 The dosage of THF is 30%and the dosage of catalyst is 2.1wt%.At this time,the average yield of EMF is 79.6 mol%;the optimal process conditions of glucose single factor test are:reaction temperature 200℃,reaction time 10 min,substrate concentration 100 g·L-1,the amount of THF is 30%and the amount of catalyst is 1.8wt%,the average yield of EMF is 41.5%.2.The addition of organic solvent will not affect the characteristics and structure of the solid catalyst,but as the number of cycles increases,the catalytic performance of USY will gradually decrease.After repeated use for 5 times,the yield of EMF will drop from 79.6%to 69.3%.3.The GC-MS analysis results of the one-pot reaction product of fructose in a twosolvent system show that 5-ethoxymethylfurfural,ethyl levulinate,2-methoxyfuran and acetal diethanol are the main ones.Compared with the solvent-free system,the product has fewer by-products,the EMF yield is increased by 6.56%,the fructose conversion rate is more than 99%,the reaction process conditions are basically unchanged,and the catalyst effect is not significantly improved;glucose is in the two-solvent system The one-pot reaction product GC-MS analysis results of the reaction product showed that 5ethoxymethylfurfural,ethyl levulinate,fructose,α-methyl-D-mannopyranoside and methyl-β-D-Glucopyranoside is the main product.Compared with the solvent-free system,the types of by-products in the product are reduced,the EMF yield is increased by 6.3%,the glucose conversion rate is 7.7%,and the reaction process conditions are basically unchanged.4.In the two-solvent system,USY and ultra-low acid(0.1 wt%H2SO4)were used to catalyze the cellulose and straw two-solvent system to prepare EMF.The GC-MS analysis results of the cellulose reaction product showed that ethyl acetate and 5-methylfuran Aldehydes and ethoxyacetaldehyde diethyl acetal are the main products.Compared with the solvent-free system,the by-products in the product are basically unchanged,and the EMF yield is increased by 3.3%.The GC-MS analysis result of the straw reaction product shows that Methyl dimethoxyacetate,ethoxyacetaldehyde diethyl acetal,ethyl levulinate,5-ethoxymethyl furfural,1,2-cyclohexanedicarboxylic acid 2-chlorophenyl ethyl Esters and 1-O,5-O,6-O-triacetyl-2-O,3-O,4-O-trimethyl-D-galactitol are the main products.Compared with the solvent-free system,its The type of product in the product is basically unchanged,and the EMF yield is 19.4%.