| The refining of the renewable non-food biomass has become one of the most effective ways to solve the shortage of non-renewable resources.At present,the degradation of other non-food biomass in the various solvent have been reported,while the degradation of the components of reed in the ethanol/water system and its kinetics few reported.Therefore,the reaction mechanism and products distribution compared with other biomass materials or solvents are the same or different is unclear.This study using reed as raw materials,the degradation of its main component,such as cellulose,hemicellulose and lignin,in the ethanol/water system was researched based on the characteristics of the auto-catalytic ethanol/water refining.Then provides a theoretical basis for ethanol pulping and utilization of high value products of waste liquor.The main contents and results are as follows:Reeds?harvested in Dalian?were hydrolyzed in 500-mL high-pressure batch reactor with the alcohol and water?V/V=50%?at different temperature for different time,the solid materials remained were washed by the solvent above,then the yield were studied.The results showed that the yields reduced when the temperature rose.Furthermore,the more temperature rose,the more the yields reduced.And the yield reduced and stabilized as the extension of the temperature.The organic acids and aldehyde were quantitatively analysed by HPLC.On account of the lignin in the liquor and material,the model of the degradation was set up.The result showed that the dissolution of lignin began when the temperature elevated and intensified when temperature was higher.The lignin degradation was designed first order reaction based on the lignin conversion rate?lignin transferred accounted for the lignin in the raw material?.The process could be divided into rapid lignin removal stage and residual lignin removal stage.The reaction rate constant was bigger when the heat preservation temperature was higher.The linear correlation coefficient were not less than 0.94,which was higher than the model based on the residual rate of lignin.IC could be used to detect the contents of xylose in the liquor and residue.The kinetics of xylan degradation was studied based on the concentration of furfural derived from xylan.The consequence showed that the xylans concentration in the residue declined badly at the higher heat preservation temperature,as the constructure of xylan at the high temperature was not steady.The lignin in the liquor rose and then reduced,and the temperature was higher,the turning point was earlier.On the occasion that,the kinetics model was set up and the reaction rate constant of the xylan and xylose degradation was bigger with the higher temperature,the activation energy of which was 289.71KJ·mol-1?206.24KJ·mol-1?156.29KJ·mol-1.Model parameters on the basis of the experimental data was consistent with the actual data,which verified the feasibility of model.Finally,the degradation kinetics of glucose was researched in auto-catalysis ethanol/water system.Meanwhile,the contents of glucose of pulp and liquor was detection using IC.The result that the degradation of cellulose occurred in the heating stage,and the higher temperature,the faster degradation.In addition,the transformation of glucosan was researched.Because of the cooking process,the cellulose degradation as glucosan,further degradation of glucose,and then glucose degraded to 5-HMF,and degradation of levulinic acid and formic acid.In this study,the combination reaction of cellulose and glucose is considered as one step reaction,and a kinetic model was established based on the conversion of cellulose.The degradation of glucose is the first order reaction according to the linear coefficient obtained.Simultaneously,the activation energy of the conversion cellulose to5-HMF is 101.488 KJ·mol-1 according to Arrhenius equation. |
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