钠盐对钙基脱硫剂烧结动力学的影响及孔结构的生成模型

Effect of Sodium Salt on Sintering Dynamics of Ca-based Sorbents and Modeling the Formation of its Porous Structure

从离子迁移现象出发探讨了钠盐杂质对CaO烧结动力学的影响。采用不等径团聚体,代替传统认为CaO晶粒都是同一尺寸的物理概念,进而通过空位缺陷方程,推导出固态离子扩散系数,从而实现对CaO烧结过程中物理结构不断变化的模拟。利用向钙基脱硫剂中添加钠盐以得到不同杂质含量的方法,研究了温度、杂质含量对CaO烧结的影响。通过实验数据和模型计算结果比较,证明了该模型的合理性。

According to the mechanism of CaO sintering, i.e., diffusion, the effect of sodium salt impurities, on sintering dynamics of Ca-based sorbents, has been investigated, It＇ s the first time that agglomerates of different sizes are assumed, instead the traditional concept that CaO crystals are all of he same size. Thereupon a solid state ion diffusivity coefficient was deduced by means of vacancy defect equations, herewith realizing the modeling of uninterrupted structural variation of CaO during its sintering processes. By adding sodium salt, as an impurity of Ca-based desulfurization sorbents, in different quantities, the effect of temperature and that of impurities on CaO sintering was then investigated. The rationality of this model has been verified, by comparing experimental data with calculation results. This method provides a way of further investigating the effect of various impurities on CaO sintering.