高等学校化学学报

高等学校化学学报 ›› 2006, Vol. 27 ›› Issue (2): 327.

• 研究论文 • 上一篇    下一篇

热重分析法研究贝壳固硫反应动力学

韩奎华, 路春美, 程世庆, 王永征, 赵建立   

  1. 山东大学能源与动力工程学院, 济南  250061
  • 收稿日期:2005-01-14 出版日期:2006-02-10 发布日期:2006-02-10
  • 通讯作者: 路春美(1958年出生), 女, 教授, 博士生导师, 主要从事清洁燃烧与污染物防治研究. E-mail: cml@sdu.edu.cn
  • 基金资助:

    国家自然科学基金(批准号: 59976019)和山东省自然科学基金(批准号: Y2003F07)资助.

Studies on the Desulfurization Kinetics of Shell Sorbent Using Thermogravimetric Analysis Method

 HAN Kui-Hua, LU Chun-Mei, CHENG Shi-Qiang, WANG Yong-Zheng, DIAO Jian-Li   

  1. School of Energy and Power Engineering, Shandong University, Jinan 250061, China
  • Received:2005-01-14 Online:2006-02-10 Published:2006-02-10
  • Contact: LU Chun-Mei,E-mail: cml@sdu.edu.cn

PDF (PC)

被引次数

11

摘要：

采用热分析法研究了贝壳和石灰石固硫反应过程, 用等效粒子模型对固硫反应过程进行了表征, 计算分析了其固硫反应动力学参数. 结果表明, 贝壳比石灰石含有较多的碱金属盐, 其作用是提高了贝壳固硫反应速率常数和有效扩散系数. 贝壳固硫反应中存在补偿效应. 根据等动力学温度判别固硫剂活性适用于不同反应控制区的活性判断. 碱金属成分对钙基固硫剂活性有正负两个方面的影响, 含量过大或过小都会削弱固硫剂活性, 因而存在最适含量. 在1 073～1 273 K温区固硫时, 钙基固硫剂中碱金属离子与钙离子摩尔比为1∶50左右时固硫活性较高.

关键词: 固硫; 动力学; 钙基固硫剂; 补偿效应; 贝壳

Abstract:

The general desulfurization sorbent, limestone is limited in sulfation temperature range and suffers from rapid loss of reactivity and incomplete utilization. However, plentiful shells are generally abandoned as garbage especially in coastal area, which consist of CaCO3 similar to limestone. Desulfurization with shell shows a higher calcium utilization and better sulfation property than limestone under various experimental conditions. The desulfurization reaction process of calcium\|based sorbent including four species of shell and a sort of limestone were investigated by thermogravimetric analysis method. The kinetic behavior was expressed by the  modified grain model. The activation energy (Ea) and the pre-exponential factor (k0) of surface reaction, the activation energy (Ep) and the pre\|exponential factor (D0) of product layer diffusion reaction were calculated and explained according to the model. It is shown that   the modified grain model can describe the desulfurization course of shells and limestone. Additions of alkali metal salts may improve microstructure and product diffusion of sorbent during high temperature sulfation, and enhance the initial reaction rate and the final CaO conversion of sorbents. The kinetic parameters of shell desulfurization show a compensation effect. There are linear relationships between logarithms of the pre-exponential factor lnk0, lnD0 and activation energies Ea, Ep respectively. The method based on the isokinetic temperature Ts to estimate sorbent activity is applied to different control stage. Alkali metal salts can enhance the initial reaction rate, at the same time can accelerate the high temperature sintering of sorbent, so there is optimal content in sorbent. The advisable molar ratio of alkali metal cations (mainly Na + and K +) to Ca2+ in the sorbent is best kept to 2% approximately at the desulfurization temperature range of 1 073-1 273 K.

Key words: Desulfurization; Kinetics; Calcium-based sorbent; Compensation effect; Shell

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