中文摘要：

采用综合热分析仪研究不同氧气浓度下K2CO3催化无烟煤和石墨燃烧的特性,考察了氧气浓度对催化燃烧机制的影响.结果表明,K2CO3提高了燃烧反应和氧气扩散速率,但对燃烧速率的提高幅度大于对氧气扩散速率提高幅度,延长了无烟煤燃烧过程的平台时间.氧气浓度由21%增加到100%时,K2CO3催化无烟煤着火温度降低幅度由37.7℃增至78.1℃,催化石墨着火温度降低幅度由204.8℃增至233.6℃.煤燃烧初期K2CO3使燃烧活化能下降,氧气浓度高于40%时,燃烧由扩散向反应控制转变;燃烧后期活化能低于40 k J/mol,燃烧受扩散控制.石墨在燃烧初期K2CO3使燃烧活化能下降,但氧气浓度增加并未改变燃烧控制步骤,燃烧受反应控制;燃烧后期氧气浓度由21%增加到100%时,K2CO3催化石墨燃烧活化能由39 k J/mol增至110 k J/mol,燃烧由扩散控制向反应控制转变.

英文摘要：

The effects of oxygen concentration on catalytic combustion, catalytic combustion reactivity of anthracite and graphite with K2CO3 were examined using TGA. The results showed that K2CO3 improved the combustion reaction and oxygen diffusion rates with the increase of oxygen concentration, but the incremental degree of combustion reaction rate was bigger, resulting in prolonging the platform time of anthracite combustion process. When the oxygen concentration increased from 21% to 100%, the extension of decreasing ignition temperature of pulverized anthracite and graphite catalyzed by K2CO3 promoted from 37.7 ℃ to 78.1 ℃ and 204.8 ℃ to 233.6 ℃, respectively. The apparent activation energy was reduced by K2CO3 in the initial combustion stage of coal, when the oxygen concentration was over 40%, the control step of combustion process changed from oxygen diffusion to chemical reaction. However, the apparent activation energy was always lower than 40 k J/mol with the increase of oxygen concentration, the combustion reaction was controlled by oxygen diffusion in the later combustion stage of coal. For graphite combustion, the apparent activation energy decreased in the initial stage with addition of K2CO3, but the chemical reaction was still the control step. In the later stage of graphite combustion in the presence of K2CO3, the reaction activation energy increased from 39 k J/mol to 110 k J/mol with the increase of oxygen concentration from 21% to 100%, resulting in that the control step of combustion process changing from chemical reaction to oxygen diffusion.