In this work,a kinetic study of the selective catalytic reduction of NO with NH3 has been carried out.After proving the operating condition that the effect of intraphase diffusion and interphase mass-transfer processe...In this work,a kinetic study of the selective catalytic reduction of NO with NH3 has been carried out.After proving the operating condition that the effect of intraphase diffusion and interphase mass-transfer processes can be ignored,the selective catalytic reduction of NO with NH3 on the catalytic activity of V2O5-WO3/TiO2 has been carried out with fixing the feed gas flow rate and composition（NO,NH3,O2） while varying the catalyst loading.Based on the experimental results of NO removal efficiency,the empirical catalytic reaction rate equation of NO with NH3 has been obtained using differential analysis.The experimental result is further proved by the graphic integral method at the temperature from 320℃ to 400℃.The reaction order is 1 to NO and zero to NH3.The reaction follows the Eley-Rideal mechanism model.展开更多
Coal-fired utility boilers are now identified as the largest source of mercury in the United States. There is speculation that the installation of selective catalytic reduction （SCR） system for reduction of NOx can ...Coal-fired utility boilers are now identified as the largest source of mercury in the United States. There is speculation that the installation of selective catalytic reduction （SCR） system for reduction of NOx can also prompt the oxidation and removal of mercury. In this paper, tests at six full-scale power plants with similar type of the SCR systems are conducted to investigate the effect of the SCR on the transformation of mercury speciation. The results show that the SCR system can achieve more than 70%-80% oxidation of elemental mercury and enhance the mercury removal ability in these units. The oxidation of elemental mercury in the SCR system strongly depends on the coal properties and the operation conditions of the SCR systems. The content of chloride in the coal is the key factor for the oxidization process and the maximum oxidation of elemental mercury is found when chloride content changes from 400 to 600 ppm. The sulfur content is no significant impact on oxidation of elemental mercury.展开更多
文摘In this work,a kinetic study of the selective catalytic reduction of NO with NH3 has been carried out.After proving the operating condition that the effect of intraphase diffusion and interphase mass-transfer processes can be ignored,the selective catalytic reduction of NO with NH3 on the catalytic activity of V2O5-WO3/TiO2 has been carried out with fixing the feed gas flow rate and composition（NO,NH3,O2） while varying the catalyst loading.Based on the experimental results of NO removal efficiency,the empirical catalytic reaction rate equation of NO with NH3 has been obtained using differential analysis.The experimental result is further proved by the graphic integral method at the temperature from 320℃ to 400℃.The reaction order is 1 to NO and zero to NH3.The reaction follows the Eley-Rideal mechanism model.
基金Project supported by the National Basic Research Program (973) of China (No. 2006CB2003)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Personnel Ministry.
文摘Coal-fired utility boilers are now identified as the largest source of mercury in the United States. There is speculation that the installation of selective catalytic reduction （SCR） system for reduction of NOx can also prompt the oxidation and removal of mercury. In this paper, tests at six full-scale power plants with similar type of the SCR systems are conducted to investigate the effect of the SCR on the transformation of mercury speciation. The results show that the SCR system can achieve more than 70%-80% oxidation of elemental mercury and enhance the mercury removal ability in these units. The oxidation of elemental mercury in the SCR system strongly depends on the coal properties and the operation conditions of the SCR systems. The content of chloride in the coal is the key factor for the oxidization process and the maximum oxidation of elemental mercury is found when chloride content changes from 400 to 600 ppm. The sulfur content is no significant impact on oxidation of elemental mercury.
