钙基固硫剂的热力学和动力学分析

Kinetic and Thermal Analyses of Calcium-based Sulfur-fixation Agent

建立了高温条件下固硫过程中自由能与温度的关系函数。固硫过程中,钙基固硫放热比吸热大得多,说明固硫过程中的热力学推动力很大。根据不同温度下固硫过程中SO2与固硫剂反应的平衡压及硫酸钙的分解压力,可以得出不同温度下钙基固硫剂的固硫能力,在1400 K左右时,CaSO4发生二次分解。温度每升高100 K,二氧化硫分压增加约一个数量级。应用物理化学中热力学函数,得到了固硫分解动力学方程,硫酸钙在高温、氧化性气氛下的反应活化能平均为Ea=227.15 kJ/mol,频率因子A=1.585×104。

The paper deals with the relational function of free energy and temperature in the process of sulfur-fixation with high temperature. In the process of sulfur-fixation, calcium-based sulfur-fixation agent released more heat, which indicates that thermodynamics is very powerful. According to the balance pressure between SO2 and calciumbased sulfur-fixation agent, and the decomposition pressure of CaSO4 in different temperatures, we got the relationship of sulfur dioxide pressure and temperature. When experimental decomposing temperature is at 1400 K, second decomposition happens. From test we can see that sulfur dioxide pressure will increase 10-fold as temperature raises 100 K. Then using the physical-chemistry thermodynamics function, we derive its dynamic equation. Meanwhile, the decomposing kinetics and stability of CaSO4 are obtained as free energy is 227.15 kJ/mol and A=1.585×10^4.