煤焦与H_2O和CO_2共气化反应动力学研究

Study of Co-gasification Kinetics of Coal Char with H_2O and CO_2

在热重分析仪上研究了煤焦与H_2O和CO_2等温气化和非等温气化的反应特性,探讨了两类气化过程动力学模型的适用性以及等温共气化反应活性位点模型的特点,并从动力学补偿效应的角度讨论了非等温共气化过程的协同效应。结果表明,等温气化与非等温气化过程可分别用收缩核模型及均相模型进行描述,共气化活性位点模型表明,高温下共气化反应遵循竞争部分相同活性位机理,其活性位点分配权重趋向于反应速率慢的一方;非等温共气化反应产生的协同效应使指前因子明显增加。

The characteristics of isothermal and non-isothermal gasification of coal char with H2O and CO2 were investigated by thermogravimetric analyzer and the kinetic models suitable for these two cases were discussed. The active site model of co-gasification was also studied to further reveal the competitive mechanism between different active sites. The feature of synergistic effect of non-isothermal co-gasification was reviewed from the analysis of kinetic compensation effect.The results showed that the shrinking core model and homogeneous model were applicable to describe the isothermal and nonisothermal gasification process respectively. The partially share active site model was used to describe the co-gasification behavior at high temperature, and the weight of active site distribution tended to the one with the slow reaction rate. Synergistic effect of non-isothermal co-gasification caused the increase of frequency factor.