Novel Regenerable Sorbent for Mercury Capture from Flue Gases of Coal-Fired Power Plant

• Published in: Environmental science & technology Vol. 42; no. 16; pp. 6205 - 6210
• Main Authors: Liu, Yan, Kelly, David J. A, Yang, Hongqun, Lin, Christopher C. H, Kuznicki, Steve M, Xu, Zhenghe
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.08.2008
• Subjects: 01 COAL, LIGNITE, AND PEAT; 20 FOSSIL-FUELED POWER PLANTS; ADSORBENTS; Adsorption; Air Pollutants - chemistry; Air Pollution - prevention & control; Aluminum Silicates - chemistry; Applied sciences; CAPTURE; COAL; Coal - analysis; Coal-fired power plants; Composite materials; Exact sciences and technology; FLUE GAS; FOSSIL-FUEL POWER PLANTS; Gases - chemistry; Incineration; MERCURY; Mercury - chemistry; Microscopy, Electron, Transmission; Nanoparticles; Pollution; Power Plants; REGENERATION; Remediation and Control Technologies; REMOVAL; SILVER; Silver Compounds - chemistry; Sorbents; SORPTION; ZEOLITES; Nanoparticle; Ultrafine particle; Zeolite; Heavy metal; Gaseous effluent; Continuous process; Sorption; Activated carbon; Aerosols; Coal power plant; Air pollution; Ion exchange; Sorbent; Mercury
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es800532b

A natural chabazite-based silver nanocomposite (AgMC) was synthesized to capture mercury from flue gases of coal-fired power plants. Silver nanoparticles were engineered on zeolite through ion-exchange of sodium ions with silver ions, followed by thermal annealing. Mercury sorption test using AgMC was performed at various temperatures by exposing it to either pulse injection of mercury or continuous mercury flow. A complete capture of mercury by AgMC was achieved up to a capture temperature of 250 °C. Nano silver particles were shown to be the main active component for mercury capture by amalgamation mechanism. Compared with activated carbon-based sorbents, the sorbent prepared in this study showed a much higher mercury capture capacity and upper temperature limit for mercury capture. More importantly, the mercury captured by the spent AgMC could be easily released for safe disposal and the sorbent regenerated by simple heating at 400 °C. Mercury capture tests performed in real flue gas environment showed a much higher level of mercury capture by AgMC than by other potential mercury sorbents tested. In our mercury capture tests, the AgMC exposed to real flue gases showed an increased mercury capture efficiency than the fresh AgMC.