Study On Effct Of Atmosphere On Formation Ofnitrogen Oxides In Fuel-coal Cement Rotary Kiln

The nitrogen oxide, which was mainly formated by the combustion of kiln coal in cement industry,has a greater harm to the ecological environment and human health, thus the formation mechanism of NO_x and reducing its emissions have became an important research subject. In this work, the structure of nitrogenous compound in the kiln coal was analyzed by X-ray photoelectron spectroscopy, the formation and reduction mechanism of NO x were detailedly analyzed combined with the theoretical and experimental results. The mixed flow model was established using the software of chemkin Pro, and the reaction rate and path of NO_x by CO simulated in the different atmosphere with the rotary kiln were studied. The results show that the formation and reduction of NO_x are different with the different atmosphere. The reduction of NO can be proceed with O2 formed under pure CO without catalyst, but the reactive temperature is high, about 1650 K. The NCO had great influence on the reduction of N2 O. NO can be decomposed except the reduction by CO, and the percent conversion is about 100% under simulated temperatures. When the NO with lower concentration about ppm order of magnitude, the reduction of NO can not be proceed.The reduction of NO_x in rotary kiln under different atmosphere, temperatures, and materials was simulated, and the catalytic activity of iron wire and platinum was contrasted by the experiment. The results show that CO has no significant influent on the reduction of NO under no-catalyst; the iron wire has the strongest catalytic action and the percent conversion of NO x is about 90% at about 1400?, the area of catalytic activity can improve the percent conversion of NO_x at a certain extent. With the concentration of O 2 increase to 5%, the three catalyst(iron wire, platinum and raw material) gradually loss of catalytic activity. The iron wire and platinum have the lower sensitivity to CO2 than raw material. The results in this work can be provid the theoretical basis in reduction technology of NO_x.