The Research On Release Characteristics Of Nitrogen Oxides From Blended Coal On The O₂/CO₂ Atmosphere

Energy production and consumption is huge in our China, national conditions decide the coal-dominated energy structure. But the NO_x emissions from coal-fired power plants cause great harm to atmospheric environment, so controlling Coal-fired power plant NO_x pollution and other gas emissions has become an important economic development goal of the process. O₂/CO₂ cycle combustion technology is an efficient, economic and environmentally friendly next-generation combustion technology, it can significantly reduce the combustion process in CO₂, NO_x, SO_x and other gas emissions, reduce the harm to the environment. This paper studies the efficacy of this technology in controlling the release NO_x from coal combustion.First of all, in the tube furnace devices, by using an infrared gaseous analyser, release characteristics of NO_x precursors HCN, NH₃ and NO_x from two single coals Indonesia Coal and Shanxi-youhun Coal under different combustion atmosphere were investigated, and got their total release rate curve and their total release amount. By comparing the characteristics of these curves, the releasing characteristics of HCN, NH₃ and other gases form coal at different atmosphere during pyrolysis were investigated, and then analysed the efficacy the factors such as coal characteristics, the atmosphere, and the oxygen concentration in O₂/CO₂ atmosphere do to the release from them.Secondly, the coal element composition was measured and made the TGA experiment of the two single coals and its blended coals, analysis of coal properties and ash content of coal. The TG, DTG curve of the mixed coal combustion characteristics were obtained, and the combustion characteristics of blended coals were investigated, the ignition characteristics, burnout characteristics of Indonesia Coal and Shanxi-youhun Coal and chemical kinetic parameters in combustion were analysed, so that the efficiency after mixing the coal to the burning combustion characteristics was obtained.Finally, on this basis, in the tube furnace equipment, the NO releaseing from blended coals under different atmosphere was investigated, especially the effect of carbon dioxide, oxygen concentration in O₂/CO₂ atmosphere on NO releaseing. Through test analysis, the effect of the mixed coal combustion to the emissions of pollutants such as NO was obtained.