Study On The Thermal Analysis Kinetics Of Coal Oxidation In Low Temperature Process

In this paper,the thermal analysis kinetics of coal samples have been studyed on 7 kinds of different coal rank.The effect of particle size and coal rank in the same heating rate to coal oxidation in low temperature has been analyzed.The paper has divided heating process of 30℃to 300℃into two stages and has given technical parameters,fist stage is oxygen absorption and desorption stage,second stage is oxygen absorption weight gain stage.And the paper has found the most probably mechanism function through Coats-Redfern integration method and Achar differential method,that adapt to Bagchi method in the lower temperature process of coal samples oxidation.Reaction mechanism function in oxygen absorption and desorption stage is reaction order model of n equal to 3,whose differentiation function is f(α)=(1-α)³,and integral function is G(α)=1/2[(1-α)^-2-1].Reaction mechanism function in oxygen absorption weight gain stage is Z-L-T equation of three dimensional diffusion model, whose differentiation function is f(α)=3/2(1-α)^4/3[1-α)^-1/3-1]^-1,and integral function is G(α)=[(1-α)^-1/3-1]².Paper also has got dynamical parameters(activation energy and preexponential constant).Through a serious of research,the paper shows that,to the different kinds of coal samples,in low temperature Process,the activation energy enlarges with reactive progressive,preexponential constant rises with activation energy rises.And the reasons have been deeply analyzed.