石灰石与SO_2反应动力学的研究

KINETICS OF THE REACTION OF SO_2 WITH LIMESTONE

石灰石与ＳＯ＿２的高温短时的硫酸化反应在夹带流反应器中被实验研究。硫酸化反应是一个两阶段反应：初始是一个非常快的零级表面反应且活化能为２１．０ｋＪ／ｍｏｌ，接着是活化能为８０．１ｋＪ／ｍｏｌ的产物层扩散控制反应，初始阶段约０．３ｓ。吸收剂的种类、Ｃａ／Ｓ比、停留时间、反应温度和ＳＯ＿２分压影响着脱硫反应速率。脱硫反应过程能用缩芯模型来模拟。在Ｃａ／Ｓ＝２、１０００℃和２ｓ的实验条件下，喷射Ｆ－石灰石能达到９０％以上的脱硫率。

The high temperature short time sulfation of limestone with SO_2 has been investigated in an entrained flow reactor(EFR).The sulfation is found to be a two-stage reaction, first with a very fast zero-order surface reaction with an activation energy of 2l.0 kJ/mol,and followed by a product layer diffusion controlled reaction with an activation energy of 80.1 kJ/mol.The initial period is about 0.3s.This process of sulfation is affected by sorbent class,Ca/S ratio,residence time, reaction temperature and SO_2 concentration. The experimental results obtained can be interpreted by means of a shrinking eore model.Above 90%of SO_2 removal is achieved for F-limestone at Ca/S=2,1000℃ and 2 s residence time.