活性炭吸附汞.ppt

Mercury Adsorption by Activated Carbon in flue gas New standard in China GB13223-2011 flue gas Hg: 0.03mg/m3 2015 coal-fired power plant Activated Carbon Feasible Reliable Physical Adsorption Chemical Adsorption Physical adsorption Porous Structure Large Surface Area Adsorption of Impurities (Molecular SizePore Size) Feature: Lower Temperature, higher mercury adsorption Physical Adsorption Chemical Adsorption Chemical adsorption Oxygen-containing: -COOH; COO-; Phenol; Carbonyl, et al. Surface Oxygen: Hg on the surface of activated carbon is always together with Oxygen. (X-ray absorption fine structure spectroscopy ) Active Sites Physical Adsorption Chemical Adsorption Chemical adsorption closed box environment : O2 + Hg0 = no reaction O2 strengthens activated carbon adsorption at 100-300℃. Bjorn Hall Physical Adsorption Chemical Adsorption Frank E. Hugginsa Chemical adsorption Adsorption form of Hg0 test (XAFS XANEs) All Hg2+ No Hg0 Sorbent surface: I, S, Cl, O, et al. Acid gas in flue gas Physical Adsorption Chemical Adsorption Stanley Chemical adsorption Basic atmosphere: O2, CO2, N2 and water at 107℃ SO2/HCl/NO/NO2 appear alone Adsorption efficiency increased to 90-100% HCl and NO / SO2 and NO2 Adsorption efficiency reduced rapidly. Physical Adsorption Chemical Adsorption 胡长兴 Hu Changxin Chemical adsorption N2 CO2→O2 →SO2 →NO2 →NO →HCl →H2O Hg2+ Hg0 Physical Adsorption Chemical Adsorption 胡长兴 Hu Changxin Chemical adsorption Treated activated carbon 863m2/g√ 0.23mg/g ? Untreated activated carbon 53m2/g ? 1.85mg/g √ Which one is the dominant? Mercede, et al Oxygen Group is more important Under atmospheric pressure: Physical adsorption Chemic