The Study Of Oxidation And Absorption Of NO_x In Sintering Gas

At present,there is no mature denitrification technology for sintering flue gas,while low temperature oxidation denitrification technology has attracted increasing attention.Compared with other denitrification technologies,the temperature window of low temperature oxidation denitrification technology is more suitable for sintering flue gas and has high oxidation efficiency under low temperature.In this paper,the application of oxidation denitrification technology in denitrification of sintering flue gas is studied in view of the working conditions of the sintering flue gas.The research contents of this paper are divided into two parts:the oxidation of NO and the absorption of NO_x.The oxidation part mainly includes the influence of O₃/NO molar ratio,reaction temperature,residence time and humidity on N₂O₅ generation.The absorption part mainly includes the effect of absorption gas composition and absorbents on the absorption efficiency of NO_x.The main conclusions of this paper are described as follows:?1?The composition of oxidation products is affected by O₃/NO mole ratio,reaction temperature and residence time.The oxidation product distributions are determined by O₃/NO mole ratio.The oxidation product is NO₂ when O₃/NO molar ratio is below 1.When O₃/NO molar ratio is above 1,some NO₂ is oxidized to N₂O₅.The concentration of oxidation products are greatly influenced by the reaction temperature and residence time.N₂O₅ is generated with the highest yield under the optimized conditions of the reaction temperature at 90^oC and residence time being 2.5s.?2?At low temperatures,presence of H₂O in the flue gas promotes the formation of N₂O₅,while the components of SO₂,CO and HCl have no apparent effect on the oxidation process.?3?The main factor that affects the absorption of NO₂ is the concentration of SO₃^2-in the absorption product.The absorption efficiency of sodium based sorbent is higher than that of calcium based absorbent,and the NO_x of high valence state is more easily absorbed.The research provided experimental and theoretical basis for the application of ozone oxidation denitrification technology at low temperature in the sintering flue gas purifications.