Analysis Of Environmental Impact Of Nitrogen Oxides In Flue Gas Of Lime Rotary Kiln

Lime industry,as an important basic raw material industry for national economic and social development,Large amounts of air pollutants are produced during production The Ministry of Environmental Protection of the People's Republic of China has issued the Announcement on the Implementation of Special Emission Limits for Air Pollution in Beijing,Tianjin and Hebei Transmission Channel Cities.The State requires the implementation of special emission limits for air pollutants on March 1,2018 for new projects of " 2+26 Cities".Special emission limits will then gradually be implemented in areas such as the fen wei plain.At present,the industry of cement has already implemented special emission limits,and the industry of lime will soon issue more stringent standards.The emission of the other two pollutants in the lime industry is under limited control,such as dust and SO2,so the NO_x is a pollutant that needs to be controlled.In this paper,the mechanism of NO_x formation in lime rotary kiln was analyzed.The formation mechanism of NO_x in lime rotary kiln is compared with that of NO_x in cement rotary kiln,the flue gas and process of lime rotary kiln were explained,and analyzes the advantages and disadvantages of denitration measures,so as to select the denitration method suitable for this process.This paper introduces the working principle of the AERMOD model used in this study as well as the required parameters,and illustrates the reliability of prediction with this model.By collecting the meteorological date,topographic date and the current situation of ambient air quality in Hejin city,Using the AERSCREEN and AERMOD models in EIAPro A2018,the influence of NO_x from a lime rotary kiln on the surrounding environment was simulated and calculated,The time and distance of the maximum landing concentration are obtained.The distribution of NO_x in the surrounding environment is simulated.It shows that the NO_x by lime kiln industry has a great impact on the environment.The distribution of NO_x in the surrounding environment after denitration was further analyzed and predicted.The necessity of installing denitration facilities and the feasibility of controlling NO_x in the area by installing denitration equipment in lime rotary kiln are explained.This study provides a theoretical basis for the treatment scheme of nitrogen oxides in the flue gas of rotary kiln and a way to reduce the concentration of nitrogen oxides in the region.