石灰石／石膏法烟气脱氟反应的动力学研究

Kinetics of fluoride removal reaction by limestone/gypsum method from flue gas

对石灰石/石膏湿法烟气脱氟反应过程进行了描述,建立了基于双膜理论的CaCO3-HF反应动力学模型,并对模型进行了计算和分析,考察了反应温度、反应时间、HF气相分压、Ca/F摩尔比等因素对反应的影响。结果表明,CaCO3颗粒的转化率和脱氟率随着反应温度、反应时间、HF气相分压的增加而增加,Ca/F摩尔比对脱氟率有重要影响,双膜理论模型可较好地描述石灰石/石膏湿法脱氟反应的动力学行为。研究结果对于典型的湿法烟气脱硫技术的气态氟化物的脱除机理研究和为开发统一的燃煤污染物控制技术具有指导意义。

The chemical reaction ,in the process of fluoride removal with limestone-gypsum from flue gas was described. Based on the two-film theory, the kinetic model of CaCO3-HF reaction was established and analyzed. The effects of reaction temperature, reaction time, HF vapor-phase pressure and ratio of Ca/F molar ratio on the fluoride removal reaction were explored. The results show that the conversion of a CaCO3 particle and the fluoride removal efficiency increase as the reaction temperature, the reaction time and HF vapor-phase pressure are raised. The molar ratio of Ca/F molar ratio significantly affects the fluoride removal efficiency. It is suggested that two-film theory model can be used to describe the dynamical behavior of fluoride removal reaction with wet limestone/gypsum. The investigation results are of important significance for studying the mechanisms of gaseous fluoride removal by the typical wet FGD techniques and developing the uniform control technology of coal-fired pollutants.