Study On Production Of 5-ethoxymethylfurfural From Monosaccharides By Ultra Stable Y Zeolite

ABSTRACT:This research was funded by the NSFC Foundation(U1904122),the'Program of Processing and Efficient Utilization of Biomass Resources' of the Henan Center for Outstanding Overseas Scientists(GZS2018004),and the Foundation and Frontier Technology Research Project of Henan Province of China(162300410158).5-Ethoxymethylfurfural(EMF)is an important platform compound and oil additive,and is considered to be a very promising alternative to fossil fuels.The use of biomass"one-pot" method to produce EMF has the advantages of wide raw material sources and simple technological processes.It is a very promising way to utilize biomass resources.Monosaccharides can be obtained directly from biomass,with sufficient resources and wide sources.At present,the one-pot alcoholysis preparation of EMF using monosaccharides as raw materials has the disadvantages of long reaction time,low yield,and complex catalyst manufacturing processes.This paper addresses these shortcomings by using commercial solid catalysts:ultra-stable Y-type molecular sieves(USY)was used as the catalyst,and the single-factor and response surface methods were used to obtain the process conditions and kinetic parameters for preparing EMF using fructose and glucose as raw materials.The reaction product distribution was analyzed by GC-MS;Recycling characteristics of the catalyst was analyzed by XRD,FTIR,and BET methods.The paper compares and analyzes the experimental results of fructose and glucose catalyzed by USY and ultra-low mass concentration dilute sulfuric acid(0.1 wt%H2SO4).The main conclusions reached are as follows:(1)Ultra-stable Y zeolite(1.0)is suitable for catalyzing the one-pot alcoholysis of fructose to produce EMF.The optiom reaction conditions are:substrate concentration 60g/L,reaction temperature 132?,catalyst dosage 2.1wt%,reaction time 25min,at this time the EMF yield was 73.8%;the best reaction conditions for the production of EMF by catalytic glucose are:substrate concentration 100g/L,reaction temperature 210?,catalyst dosage 2.1wt%,reaction time 10min,at this time the EMF was 41.8%.The yield of USY catalyzed fructose EMF is slightly lower than that of liquid acid catalyzed fructose EMF,but the USY solid catalyst can be separated from the reaction product without causing harm to the environment,and also has a certain recyclability.(2)GC-MS analysis of the alcoholysis products of fructose and glucose catalyzed by USY and ultralow acid.The results showed that the main alcoholysis products of ultralow acid and fructose catalyzed by USY are:5-ethoxymethylfurfural The main difference is that USY is used as a catalyst,the main by-products are ethyl levulinate,1,2-cyclohexanedicarboxylic acid and 3-fluorobenzyl alcohol.When ultra-low acid is used as a catalyst,the main by-product is acetyl Ethyl propionate and ethyl adipate;when USY catalyzes glucose,the main products are methyl ?-D glucopyranoside and 5-ethoxymethylfurfural;when ultra-low acid catalyzes glucose,the main product is acetyl Ethyl propionate and a small amount of 5-ethoxymethylfurfural.USY is more helpful in the synthesis of 5-ethoxymethylfurfural,and ultra-low acid is helpful in the synthesis of ethyl levulinate.The conversion rate of the two monosaccharides during the reaction is basically higher than 95%.(3)After recycling the USY after the reaction,the catalyst was reused 5 times,and the EMF yield decreased.FTIR,XRD,and BET were used to characterize the USY before and after use.The characteristic peaks and diffraction peaks of the USY remained unchanged.The specific surface area has decreased,and the pore volume and pore size have not changed substantially.It is concluded that the USY after the reaction still maintains a good structure and good stability.The decrease in the EMF yield may be due to the lower USY recovery rate and carbon deposition on the surface.(4)Analyze the results of kinetic tests of USY catalyzed fructose and glucose.Combining the results of GC-MS analysis of liquid phase products,a possible reaction path for the production of EMF by USY catalyzed fructose and glucose is proposed.