Development of SNCR Technology and Prospects of Its Application

The state of and development prospects for the technology of selective noncatalytic reduction (SNCR) of nitrogen oxides in the combustion products of organic fuels are considered. Its advantages and disadvantages and factors influencing the efficiency of its application for gas purification of technological furnaces for natural gas conversion at power and waste incineration boilers are analyzed. The results of experimental studies into the process of reducing nitrogen oxides by products of thermal decomposition of carbamide are presented, depending on the temperature, flow rate, and the method of introducing the reagent into the flue gases. The results of pilot tests and industrial implementation of the technology are shown. The possibility of increasing the technical and economic indicators of SNCR plants by organizing a multizone injection of the reducing mixture into the gases to be cleaned with a flow rate less than the stoichiometric one is substantiated, which makes it possible to achieve high technology efficiency with a minimum ammonia slip. Relatively low capital costs for the construction of SNCR plants and the manufacture of main equipment at domestic enterprises and the small area required for equipment placement can significantly reduce emissions of nitrogen oxides into the atmosphere, even at operating boilers in a short time. It is advisable to widely introduce SNCR technologies at pulverized coal TPPs and enterprises for thermal waste disposal as one of the best available technologies.