Energy & Fuels, Vol.31, No.11, 12867-12874, 2017
Catalytic Effects of CeO2/Fe2O3 and Inherent Mineral Matter on Anthracite Combustion Reactions and Its Kinetic Analysis
Effects of external and internal catalysts on anthracite combustion reactivity and kinetics were investigated using the method of differential thermal analysis (DTA). It was found that the combustion reactivity of both raw and demineralized anthracites was all apparently improved by the introduction of CeO2 and Fe2O3. When CeO2 and Fe2O3 were used in raw anthracite, the combustion starting time from the DTA curve was advanced from 1470 to 1312 and 1325 s, respectively, as compared to the improvements from 1285 to 1089 and 1055 s while adding the same amounts of CeO2 and Fe2O3 into demineralized anthracite. The addition of catalysts has increased the combustion rate for raw anthracite much more significantly than that for demineralized anthracite. Reformed differential thermal analysis (RDTA, change the reference material from Al2O3 to raw anthracite) showed a direct effect of catalysts on its combustion, which broadly agreed with the results of the DTA study. The inherent mineral matter at high contents could potentially prevent the catalytic activity of CeO2. The kinetic study has demonstrated that the combustion reactions of all samples could see the two-stage scheme phenomena with different values of apparent activation energy and different fitting models. The addition of CeO2 and Fe2O3 has reduced the activation energy for demineralized anthracite more than that for raw anthracite.