Study of the Reaction of Lime with HCl under Simulated Flue Gas Conditions Using X-ray Diffraction Characterization and Thermodynamic Prediction
Study of the Reaction of Lime with HCl under Simulated Flue Gas Conditions Using X-ray Diffraction Characterization and Thermodynamic Prediction
复制标题
DOI：
10.1021/ie058021v
复制
发表时间：
2005-10
影响因子：
4.2
通讯作者：
Terence Chin;and Rong Yan;D. T. Liang
中科院分区：
文献类型：
--
作者：
Terence Chin;and Rong Yan;D. T. Liang
在干法洗涤工艺中，通常使用熟石灰（Ca（OH）2）作为吸附剂从烟道气中去除盐酸（HCl）。尽管该方法相对容易操作并且石灰吸附剂便宜，但是由于接触时间短并且缺乏对石灰在复杂烟道气系统中的反应化学的理解，该方法是非常低效的，因为所使用的石灰中只有约25%被转化。在含有SO2、CO2、O2和水分的模拟烟气系统中，对熟石灰与HCl反应的产物进行了全面的X射线衍射（XRD）表征。结合热力学计算，探讨了该体系中发生的多个反应的化学本质。结果表明，在模拟烟气条件下，熟石灰与HCl反应生成的产物主要为Ca（OH）Cl、CaCl 2、CaCO 3、CaSO 3·1/2 H2O、CaSO 4·2 H2O和无水CaSO 4。已有的研究结果表明，CO2和SO2的存在对系统的稳定性有重要影响。
Hydrochloric acid (HCl) is commonly removed from flue gases using hydrated lime (Ca(OH)2) as a sorbent in the dry scrubbing process. Although this method is relatively easy to operate and the lime sorbent is cheap, this process is highly inefficient, as only ∼25% of the lime used is converted, due to the short contact time and the lack of understanding of the reaction chemistry of lime in a complex flue gas system. A comprehensive X-ray diffraction (XRD) characterization was carried out on the product of a hydrated lime reaction with HCl in a simulated flue gas system containing SO2, CO2, O2, and moisture. Together with thermodynamic calculations, the chemical nature of the multiple reactions that happened in this system was investigated. It was confirmed that the products of hydrated lime with HCl under the simulated flue gas conditions were chiefly Ca(OH)Cl, CaCl2, CaCO3, CaSO3·1/2H2O, CaSO4·2H2O, and anhydrous CaSO4. Previous results suggested that the presence of CO2 and SO2 in the system formed produ...