Simultaneous Removal of SO2 and Trace SeO2 from Flue Gas:  Effect of SO2 on Selenium Capture and Kinetics Study

• Published in: Environmental science & technology Vol. 40; no. 24; pp. 7919 - 7924
• Main Authors: Li, Yuzhong, Tong, Huiling, Zhuo, Yuqun, Wang, Shujuan, Xu, Xuchang
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.12.2006
• Subjects: Air pollution; Applied sciences; Atmospheric pollution; Coal; Combustion and energy production; Diffusion; Environmental protection; Exact sciences and technology; Flue gas; Kinetics; Pollution; Prevention and purification methods; Selenium; Selenium - chemistry; Selenium Compounds - isolation & purification; Selenium Oxides; Sulfur; Sulfur Dioxide - isolation & purification; Selenium dioxide; Gas solid adsorption; Carbon burning; Calcium oxide; Coal; Simultaneous reaction; Physicochemical purification; Adsorbent; Performance; Flue gas purification; Chemical reaction kinetics; Sulfur dioxide
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es061709u

Sulfur dioxide (SO2) and trace elements are all pollutants derived from coal combustion. This study relates to the simultaneous removal of SO2 and trace selenium dioxide (SeO2) from flue gas by calcium oxide (CaO) adsorption in the moderate temperature range, especially the effect of SO2 presence on selenium capture. Experiments performed on a thermogravimetric analyzer (TGA) can reach the following conclusions. When the CaO conversion is relatively low and the reaction rate is controlled by chemical kinetics, the SO2 presence does not affect the selenium capture. When the CaO conversion is very high and the reaction rate is controlled by product layer diffusion, the SO2 presence and the product layer diffusion resistance jointly reduce the selenium capture. On the basis of the kinetics study, a method to estimate the trace selenium removal efficiency using kinetic parameters and the sulfur removal efficiency is developed.