| The CO2 gasification reactivity of Yima coal char were investigated by NETZSCH STA409 thermo-gravimetric analysis at ambient pressure and at temperatures range from 1000℃to 1400℃. And the elevated gasification reactivity was studied by TherMax500 under the temperature range of 900℃to 1050℃and pressure range of 0.2MPa to 1.5MPa. TG-DSC, XRD and SEM were employed to observe phase changes and reaction of mineral under oxidation atmosphere.The results showed that that general gasification reactivity and reaction of chars increased with gasification temperature, but some different phenomenon appeared near coal ash fusion point. Shrinking core model was used to study reaction kinetics and found that activation energy was lower at high temperature than low temperature. Under pressured coal chars gasification reactivity and rate increased with elevated temperature, which accords with the preliminary studies of atmospheric. And elevated pressure was beneficial to gasification reactivity, but at high pressure the effect of increase was not obvious, and influence of temperature was stronger compared to pressure. The reaction rate was fast at initial stage and the declined. Kinetic parameters were discussed in this paper. The relationship between reaction rate and temperature was consistent with Arrhenius law. Reaction order decreases with increasing with temperature and the relationship was similar to linear. The activation energy is about 60.02kj/mol. The disparity of coal ash minerals was decline under high temperature and agglomerated to big particle, and finally coal ash was melt. The catalysis would undermine because of non-catalytic role of minerals generated, as well as the reduction of mineral dispersion, aggregation behavior. The gasification reaction rate would reduce because ash would melt, which will plug the coal surface pores and increase gas diffusion resistance.
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