Research On The Process Of The Conversion Of Corn Cob Into Furfural In ?-Valerolactone

Cellulosic biomass is a renewable,non-fossil carbon source.Cellulosic biomass is mostly from agricultural and forestry solid waste.However,there are some drawbacks such as low utilization rate and environmental pollution in the utilization of agricultural and forestry solid waste.The use of agricultural and forestry waste as raw material to produce chemicals is one of the effective ways to realize the solid waste utilization Corn cob is a common agricultural and forestry solid waste in our country,which is rich in hemicellulose.It has the characteristics of large reserves,wide distribution and ubiquitous.It is usually used as the main raw material for the preparation of furfural.The traditional furfural preparation process has the problems of waste of raw materials,low utilization rate,large output of waste water and easily causing secondary environmental pollution.In order to reduce the pollution of the furfural industry,this study started with the control of the source of pollution in the furfural industry,which was mainly from the search for green solvents and solid acid catalyst for both new reaction system development.The use of?-valerolactone as solvent avoids the use of steam in the production of furfural,which effectively reduces the yield of furfural wastewater.H-ZSM-5 zeolite as a solid acid catalyst instead of mineral acids significantly reduced the generation of waste acid.The main contents of this paper are as follows:In order to achieve efficient conversion of corn cob,the study optimize the reaction conditions of the preparation of furfural from corn cob.The reaction conditions are as follows:under the condition of medium temperature (170-190?),using 0.02-0.10% sulfuric acid as catalyst,using?-valerolactone or pure water as solvents.The results showed that the maximum yield of conversion of corncob into furfural was 99.50%,the reaction conditions were 190?,0.10% sulfuric acid,?-valerolactone contained of 20% water,20min.The Seaman model is applied to the kinetics of furfural production.The results showed that?-valerolactone increased the furfural formation rate and decreased the furfural degradation rate.In addition,compared with water,?-valerolactone reduced the activation energy of furfural production and increased the activation energy of furfural degradation.In order to reduce the generation of mineral waste acid,a highly efficient green reaction system"?-valerolactone+H-ZSM-5"was proposed.The concentration of hydrolysis productsfrom corn cob was investigated by comparing the silica-alumina ratio of H-ZSM-5,the amount of catalyst,the reaction temperature,the water content of?-valerolactone.The hydrolyzate concerntrations of of corn cob were analysis.The optimum conditions for the hydrolysis reaction of corncobs were obtained by single factor analysis.The maximum furfural concentration was 4.12 g/L.The corn cob samples before and after reaciton were analyzed by SEM and XRD analysis.The composition and structure of the corncob samples were analyzed by these methods.The results showed that H-ZSM-5 zeoliteas solid acid catalyst can effectively hydrolyze the hemicellulose in corn cob.In order to systematically study the reaction process of corncob (agricultural and forestry solid wastes) in the production of chemicals catalyzed by solid acid.The kinetic model of H-ZSM-5 catalyzed furfural production from corn cob in?-valerolactone was established.The kinetic conditions were 20-50 g/L H-ZSM-5,the reaction temperature is 170-210?,the solvent is 20%water content of?-valerolactone.The model is consistent with the experimental data,the correlation coefficient R~2>0.90.The activation energy of H-ZSM-5 catalyzed conversion of corncob to furfural was calculated to be 67.67 kJ/mol throughan improved Arrhenius equation.