The Preliminary Study On Building And Application Of Mathematical Model Based On Corncob Hemicellulose Producing Xylose By Hydrolysis

Xylose is an important food sweetener and fine chemical,which has great value for exploitation in industrial production,and exploring the optimum conditions for xylose production is a relatively popular topic in industrial production.In this study,a pilot steam blasting experiment was used as an entry point to design experiments,collect data and fit parametric equations to finally form model parametric equations that can describe the process of hydrolysis of corn cobs to produce xylose and predict xylose yield.The research of the thesis is divided into three parts.The first part of the study is the development of reaction kinetics equations for the hydrolysis of maize cob hemicellulose to produce xylose under ideal conditions.Four reaction temperature gradients of 170,180,190 and 200℃ were designed for the hydrolysis reaction under laboratory conditions using purified maize cob hemicellulose as the raw material.The H2SO4 hydrolysate ratios were 0.92 g/L、1.80 g/Land 2.76 g/L,and the ratio of material to hydrolysate in the reaction system was 1:10.The product concentrations were determined by high performance liquid chromatography and the parameters were fitted to the derived model expressions to form the reaction kinetics equations.T showed that,unlike the ideal model,the model equation fitted the va xylose yield at full temperature(170-200℃)better-during the hydrolysis reaction,where R2 was 0.69 and MAE was 5.35,which v than the model equation fitted for corn cob hemicellulose hydroly ideal state.The second part of the study was to establish the reaction equations for the hydrolysis of corn cobs to produce xylose under]conditions and to provide a basis for validating the parametric condil pilot-scale steam-blasted corn cob hydrolysis experiment.The exp conditions were designed to remain the same as in Part I.Hydrolysis collected and then combined with parametric expressions for a secc of the equations.The results showed that,unlike the ideal model,1 equation was fitted to the variation of xylose yield at full tempera 200℃)during the corn cob hydrolysis reaction as follows:where R2 and MAE was 5.35,the regression coefficients were not significantly from those obtained in Chapter 2,but the mean error was relatively sThe third part of the study was to obtain reaction kinetic equa provide yield predictions for xylose production from corn cob steam Using the experimental conditions predicted by the model equation in Part II,hydrolysis experiments were conducted to collect data and this,parameters were optimized to obtain model equations with xy prediction value.The equations obtained had a good fit,where R2 and MAE was 0.56.The final predicted optimum conditions for xylose production maize cob steam bursting experiment(within the set conditions)v g/L acid concentration of sulphuric acid at 200℃,2.5 min reaction a predicted xylose yield of 15.11 g/L.This thesis aims to optimize the conditions for the production of xylose by steam blasting of corn cobs,combining model derivation and data fitting to establish a mathematical model for the production of xylose by hydrolysis of corn cobs.The applicability of the model to the three reaction systems was investigated and the prediction equation for xylose production from steam blasting of corn cobs was obtained after modifying the parameters to assist in the prediction and optimization of the optimum conditions for industrial production of xylose.