化学学报 ›› 2000, Vol. 58 ›› Issue (11): 1316-1321. 上一篇    下一篇

研究论文

催化剂对CaO固硫反应动力学的影响

武增华;寇鹏;邱新平;薛方渝;陈昌和   

  1. 清华大学化学系.北京(100084);清华大学热能系
  • 出版日期:2000-11-15 发布日期:2000-11-15

Effects of catalysts on the kinetics of CaO desulfurization

Wu Zenghua;Kou Peng;Qiu Xinping;Xue Fangyu;Chen Changhe   

  1. Tsing Hua Univ, Dept Chem.Beijing(100084)
  • Online:2000-11-15 Published:2000-11-15

提高CaO的固硫率是对煤炭燃烧污染防治的研究热点。本研究探索用催化剂提高CaO固硫率的可行性及其对固硫反应动力学的影响。用热天平测试了在CaO中添加不同催化剂的固硫反应的进程,并采用等效粒子模型处理实验数据,计算了表面化学反应控制阶段及产物层扩散控制阶段的动力学参数。实验表明,CaO固硫反应初期为表面化学反应控制阶段,后期转为产物层扩散控制阶段。以碱金属的盐类为催化剂,它们均能使固硫反应前期的化学反应控制阶段的反应活化能下降,并按Li,Na,K,Cs的顺序依次递减,而碱金属盐的负离子主要影响产物层扩散阶段的固硫反应。

关键词: 氧化钙, 反应动力学, 催化剂, 固硫反应, 二氧化硫

Kinetics of CaO desulfurization reaction and the effects of some catalysts on it were investigated by thermogravimetric analysis method. the results showed that the conversion of CaO increases with the increase of temperature. The kinetic behavior of desulfurization can be explained by grain model. The activation energy of surface reaction (E~a) and the activation energy of product layer diffusion (E~p) were determined by using the model. The overall rate of desulfurization is controlled initially by surface chemical reaction, and then shift to product layer diffusion control. Some alkali metal chlorides were chosen as catalysts. These salts can improve both the initial reaction rate and final fraction conversion of CaO. E~a decreases orderly when the added catalysts changed from Li, Na, K to Cs, while E~p increases.

Key words: CALCIUM OXIDE, REACTION KINETICS, CATALYST, SULFUR DIOXIDE

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