Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laborat...Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laboratory-scale reactor. Effects of several key operational parameters on NO removal efficiency are studied, including TiO2 content, H2O2 initial concentration, UV lamp power, NO initial content, oxygen volume fraction and TiO2/H2O2 solution volume. The results illustrate that the NO removal efficiency increases with the increasing of H2O2 initial concentration or UV lamp power. Meanwhile, a lower NO initial content or a higher TiO2/H2O2 solution volume will result in higher NO removal efficiency. In addition, oxygen volume fraction has a little effect.The highest NO removal efficiency is achieved at the TiO2 content of 0.75 g/L, H2O2 initial concentration of 2.5 mol/L, UV lamp power of 36 W, NO initial content of 206×10-6 and TiO2/H2O2 solution volume of 600 m L. It is beneficial for the development and application of NO removal from coal-fired flue gas with UV/TiO2/H2O2 process.展开更多
Elemental mercury（Hg^0）re-emissions from slurries and solutions were evaluated in a lab-scale simulated scrubber.Oxidized mercury（Hg^2 ＋）standard solution was injected into the simulated scrubber at a desired rat...Elemental mercury（Hg^0）re-emissions from slurries and solutions were evaluated in a lab-scale simulated scrubber.Oxidized mercury（Hg^2 ＋）standard solution was injected into the simulated scrubber at a desired rate to simulate absorbing and dissolving of Hg^2 ＋in the flue gas across wet flue gas desulfurization（WFGD）systems. PS analytical mercury analyzer was used to continuously determine Hg0re-emission concentrations in the carrier gas from the scrubber.Sulfite ion in the slurry of CaSO3 was validated to reduce Hg ^2＋to Hg^ 0,while no Hg ^0 re-emission occurred from slurries of CaSO4 and CaO.Transitional metal ions with low chemical valence such as Fe^2 ＋,Pb ^2＋,Ni ^2＋, AsO2^-and Cu ^＋were used to prepare solutions with concentration levels of mmol·L^-1.Reduction reaction of Hg^2 ＋to Hg 0was observed from these solutions.Reduction capabilities for the different transitional metal ions in the solutions were：Pb^2 ＋〉Cu ^＋〉Fe^ 2＋〉 AsO2^-〉Ni ^2＋.展开更多
基金Project(2011CB201505)supported by the National Key Basic Research Program of ChinaProject(BA2011031)supported by the Special Fund of Transformation of Scientific and Technological Achievements of Jiangsu Province,China
文摘Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laboratory-scale reactor. Effects of several key operational parameters on NO removal efficiency are studied, including TiO2 content, H2O2 initial concentration, UV lamp power, NO initial content, oxygen volume fraction and TiO2/H2O2 solution volume. The results illustrate that the NO removal efficiency increases with the increasing of H2O2 initial concentration or UV lamp power. Meanwhile, a lower NO initial content or a higher TiO2/H2O2 solution volume will result in higher NO removal efficiency. In addition, oxygen volume fraction has a little effect.The highest NO removal efficiency is achieved at the TiO2 content of 0.75 g/L, H2O2 initial concentration of 2.5 mol/L, UV lamp power of 36 W, NO initial content of 206×10-6 and TiO2/H2O2 solution volume of 600 m L. It is beneficial for the development and application of NO removal from coal-fired flue gas with UV/TiO2/H2O2 process.
基金Supported by the US Agency for International Development(USAID)cooperation agreement(486-A-00-06-000140-00)
文摘Elemental mercury（Hg^0）re-emissions from slurries and solutions were evaluated in a lab-scale simulated scrubber.Oxidized mercury（Hg^2 ＋）standard solution was injected into the simulated scrubber at a desired rate to simulate absorbing and dissolving of Hg^2 ＋in the flue gas across wet flue gas desulfurization（WFGD）systems. PS analytical mercury analyzer was used to continuously determine Hg0re-emission concentrations in the carrier gas from the scrubber.Sulfite ion in the slurry of CaSO3 was validated to reduce Hg ^2＋to Hg^ 0,while no Hg ^0 re-emission occurred from slurries of CaSO4 and CaO.Transitional metal ions with low chemical valence such as Fe^2 ＋,Pb ^2＋,Ni ^2＋, AsO2^-and Cu ^＋were used to prepare solutions with concentration levels of mmol·L^-1.Reduction reaction of Hg^2 ＋to Hg 0was observed from these solutions.Reduction capabilities for the different transitional metal ions in the solutions were：Pb^2 ＋〉Cu ^＋〉Fe^ 2＋〉 AsO2^-〉Ni ^2＋.
