多相条件下镁离子催化氧化亚硫酸钙的动力学研究

Study on oxidation kinetics of calcium sulfite catalyzed by magnesium ion under heterogeneous condition

提出将氯化镁作为添加剂应用于湿法脱硫工艺中的亚硫酸钙氧化系统。通过改变pH值、亚硫酸钙质量浓度、催化剂质量浓度、氧气分压、温度等条件,实验研究了多相条件下镁离子催化氧化亚硫酸钙的动力学,得到反应对于亚硫酸盐为零级响应、氧气分压为0.5级响应、镁离子为零级响应的结果。结合数学模型,可以推断在实验条件下,总反应速率受氧的扩散传质控制。镁离子的加入增大了反应速率常数,但并未改变各反应物的反应级数。

Magnesium chloride was proposed as additive in the oxidation system of calcium sulfite in wet limestone scrubbing in this paper. The oxidation kinetics of calcium sulfite was experimentally studied under heterogeneous condition by varying pH, mass concentration of calcium sulfite and catalyst, oxygen partial pressure and temperature. The results show that the oxidation rate is zero order in sulfite, 0.5 order in oxygen partial pressure and zero order in magnesium ions. Combined with the mathematical model, it can be concluded that the general reaction rate is controlled by mass-transfer of oxygen. The velocity constant of reaction is increased as a result of magnesium ions adding, while the reaction orders of reagent aren＇t changed.