Removal of elemental mercury by KI-impregnated clay

• Published in: Frontiers of environmental science & engineering Vol. 10; no. 2; pp. 236 - 243
• Main Authors: SHEN, Boxiong, CHEN, Jianhong, CAI, Ji
• Format: Journal Article
• Language: English
• Published: Beijing Higher Education Press 01.04.2016; Springer Nature B.V
• Subjects: Activated carbon; Adsorbents; Chemical reactions; Clay; Earth and Environmental Science; elemental mercury; Environment; Fixed bed reactors; Fixed beds; Flue gas; mechanism; Mercury; Mercury (metal); potassium iodide; removal efficiency; Research Article; SO2; Sulfur dioxide; Vapor phases; 元素; 化学反应; 吸附剂; 固定床反应器; 气浸; 汞; 粘土; removal efficiency; elemental mercury; mechanism; clay; potassium iodide
• ISSN: 2095-2201; 2095-221X
• DOI: 10.1007/s11783-014-0765-7

This study described the use of clay impreg- nated by KI in gas phase elemental mercury （Hg°） removal in flue gas. The effects of KI loading, temperature, 02, SO2 and H20 on Hg°removal were investigated using a fixed bed reactor. The Hg° removal efficiency of KI-clay with 3% KI loading could maintain at a high level （approxi- mately 80 %） after 3 h. The KI-clay demonstrated to be a potential adsorbent for Hg° removal when compared with activated carbon based adsorbent. 02 was found to be an important factor in improving the Hg° removal. 02 was demonstrated to assist the transfer of KI to I2 on the surface of KI-clay, which could react with Hg° directly. NO and SO2 could slightly improve Hg° removal, while H20 inhibited it greatly. The results indicated that after adsorption, most of the mercury escaped from the surface again. Some of the mercury may have been oxidized as it left the surface. The results demonstrated that the chemical reaction primarily occurred between KI and mercury on the surface of the KI-clay.