Preparation of SiO₂–TiO₂ Nanocomposite and Its Application on Elemental Mercury Removal in Simulated Flue Gas

Abstract:

SiO₂–TiO₂ nanocomposite was synthesized by an ultrasound-assisted pure physical method to oxidize elemental mercury (Hg⁰) in simulated flue gas. Due to its low cost and photocatalytic ability, SiO₂ was used to dope TiO₂ to modify the TiO₂ photocatalyst. We put different ratio of TiO₂ / SiO₂ under the UV irradiation to get a low Ti/Si doping ratio and high flue gas mercury removal efficiency of SiO₂–TiO₂ nanocomposite catalyst. It was found that the photocatalytic activity of nanocomposite materials did not significantly improve, or even decline. This is mainly because that the presence of too much porous SiO₂ may affect TiO₂ on the effective absorption of light and direct adsorption of contaminants. When Ti: Si ratio was 2:1, SiO₂–TiO₂ nanocomposite catalyst reached its highest elemental mercury removal efficiency in the simulated flue gas.

• Periodical: Advanced Materials Research (Volumes 960-961)
• Pages: 456-461
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.960-961.456
• Online since: June 2014
• Authors: Xue Shi, Bu Ni, Chao En Li, Xian Li, Chong Zhang, Tao Hu, Jiang Wu
• Keywords: Flue Gas Mercury, Ratio of TiO₂, SiO₂–TiO₂ Nanocomposite, Uv Irradiation

References

[1] Jie Zhang, Weiguo Pan, Guosong Wei. Control and Emissions of Mercury from Coal-fired Utility Boilers. Boiler Technology, 2007, 38 (1): 32 -35. ( In Chinese).

[2] Thomas D Brown, Dennis N Smith, Richard A Hargis, et a1．Mercury measurement and its control：what we know, have learned, and need to further investigate．Journal of the Air & Waste Management Association, 1999, 6．( In Chinese).

DOI: 10.1080/10473289.1999.10463841

[3] Yi Zhao, Zili Zhang. Research reviews of mercury control technology in the coal - fired power- plants. Electric Power Technology and Environmental Protection, 2010, 26 (4): 31-33.

[4] XU Wen-ding, SHI Lin, GENG Man. Research Reviews of Mercury Control Technologies for Coal-fired Power Plants. Power System Engineering, 2006, 22 (6): 1 -4. ( In Chinese).

[5] Zhang Yuefeng, Zhang Yuqing Applica tions and Research Progress of Composite Nano - SiO2. Journal of Tarim University. 2012, 22 (1): 151 -156. ( In Chinese).

[6] YING LI, CHANG-YU WU. Role of Moisture in Adsorption, Photocatalytic Oxidation and Reemission of Elemental Mercury on a SiO2-TiO2 Nanocomposite. Environ. Sci. Technol. 2006, 40, 6444 -6448. ( In Chinese).

DOI: 10.1021/es061228a

[7] YANG Yi, WANG QiWei, WANG LianJun. Catalyst of Nanometer TiO2/SiO2 Composite. Environmental Science & Technology. 2009, 4: 9 -13. ( In Chinese).

[8] ChinSan Wu. Synthesis of Polyethylene-Octene Elastomer/ SiO2-TiO2 Nanocomposites via In Situ Polymerization: Properties and Characterization of the Hybrid. Published online in Wiley InterScience (www. interscience. wiley. com).

DOI: 10.1002/pola.20649

[9] Ying Li, Chang-Yu Wu. Kinetic Study for Photocatalytic Oxidation of Elemental Mercury on a SiO2/TiO2 Nanocomposite. Environmental Engineering Science. 2007, 1: 3 -11. ( In Chinese).