Thermal Analysis Kinetics Study Of Thermal Reaction Of Straw

China is a large agricultural production country,the annual straw output is huge,but the existing agricultural utilization methods of corn straw utilization efficiency is not high,and it is difficult to popularize and apply in large quantities.Straw is mainly composed of cellulose,hemicellulose and lignin.The study of thermal analysis kinetics of straw and its three components is of great significance for the development and utilization of straw biomass.In this paper,DAEM model is mainly selected for pyrolysis kinetics fitting analysis,and Matlab software programming is used to fit and solve the kinetic parameters.The fitting of thermal analysis kinetic parameters must first verify the stability of the program.In this paper,different reaction models are selected,and the simulation data is calculated according to the given parameters.According to the composition of straw,thermogravimetric experiments were conducted on straw biomass and three components.Through program fitting,the simulation data and the kinetic parameters of real biomass were obtained,and the reaction mechanism of thermal analysis kinetics was analyzed.With the increase of the reaction temperature to 500K,the conversion rate of cellulose pyrolysis increased significantly,while at about 600K,the conversion rate decreased significantly and tended to be stable.The entire pyrolysis reaction process was faster and more concentrated.When the reaction temperature is increased to 590K,the hemicellulose pyrolysis conversion rate is significantly increased.When the reaction temperature is increased to about 650K,the hemicellulose pyrolysis conversion rate is significantly reduced and tends to be stable.The pyrolysis reaction process is the fastest and most concentrated,with 80%weight loss in the 60K temperature range.The straw pyrolysis rate increased at 500K and reached the maximum at 600K.The main pyrolysis range was 500K～650K.Through the performance analysis of different selection models,it is found that the first-order and second-order responses satisfy the DAEM model,Weibull model,and the peak of the origin.The objective functions obtained by selecting different parameters are all less than 1e-6.The sensitivity analysis selection of different models and the thermogravimetric experiment data of straw samples,we obtained the local sensitivity changes of A、E and c,which is helpful for the qualitative and quantitative study of the impact of dynamic parameter changes on the output of the dynamic model.According to the parameters obtained by DAEM model,the contents of physically mixed cellulose and hemicellulose are 21.25%and 54.33%,respectively,which are close to the experimental blending ratio of 25.58%and 66.55%.For the content of important components in real biomass,the content of cellulose and hemicellulose is 35.66%and 14.41%,which is close to the experimental values of 34.68%and 11.34%..