摘要
采用热分析方法研究工业废弃物和石灰石的固硫反应,借助等效粒子模型表征固硫反应,并计算和分析固硫反应动力学参数。结果表明,等效粒子模型能较好地描述废弃物的固硫反应,反应存在补偿效应;等动力学温度方法适用于不同固硫控制阶段的反应活性判别;相同实验条件下,所选4种废弃物和石灰石的化学反应速率常数k差别不大,但废弃物的产物层有效扩散系数Ds比石灰石的大一个数量级,说明由于废弃物内的Ca2+向产物层表面的迁移扩散,大大增强了废弃物扩散控制阶段的反应活性;废弃物和石灰石的扩散活化能Ep,都比各自的反应活化能Ea大,说明产物层扩散比固体表面化学反应更难进行,产物层扩散成为控制固硫反应的决定性因素。
Desulfurization reactions of calciferous industrial wastes and limestone were studied by means of thermogravimetric analysis method.The modified grain model was used to describe the sulfation process and the kinetic parameters of the desulfurization reaction were calculated and analyzed.The results show that the grain model can effectually describe the sulfation process of the industrial wastes,and compensation effect of the kinetic parameters exists in the whole desulfurization reaction.The method based on isokinetic temperature（TS） to judge sorbent activity can be applied to different control stages of the sulfation course.The surface chemical reaction rate constants（k） of the chosen industrial wastes and limestone are all in the same order of magnitude approximately,however,the effective diffusion coefficients（Ds） of the wastes are bigger one order of magnitude than those of the limestone respectively.The reason for this is that the cation Ca2＋ can diffuse and transfer to the product-layer surface of the sorbents,which greatly enhances sulfation reaction activity of the industrial wastes.The diffusion activation energy（Ep） of the wastes and limestone is bigger respectively than its own reaction activation energy（Ea）,which shows that the product-layer diffusion is more difficult to carry out than the surface chemical reaction,and the product-layer diffusion is one decisive factor to control the whole desulfurization reaction.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2011年第2期39-44,共6页
Proceedings of the CSEE
基金
国家自然科学基金项目(59976019)
山东省自然科学基金项目(Y2003F07)~~
关键词
工业废弃物
固硫
动力学
补偿效应
石灰石
industrial wastes
desulfurization
kinetics
compensation effect
limestone
