Study On Simultaneous Desulfurization And Denitrification From Flue Gas Using Urea-Additive Solution

The air pollution is one of the serious problems that concern human society survival and development in the 21st century. The emission of sulfur dioxide-SO₂ and nitrogen oxides-NOx from the flue gas is mainly responsible for the acid environment, one of today's main air pollution. Flue gas cleaning is the most efficient method to reduce SO₂ and NOx. Among the general methods aiming at the reduction of SO₂ and NO_x, the technologies of the simultaneous desulfurization and denitrification, which have the advantages of being simple with less equipment, lower capital and operating costs, higher SO₂ and NOX removal efficiencies and limited secondary waste generation, are preferred ways of flue gas cleaning. A pack absorption tower filled disorderly with stainless steel pall ring was used in whole research. The parameters of absorption tower were below: the diameter of tower and ring is four centimeters and sixteen millimeters, respectively, the velocity of flow at overflow is 2.0～1.5 m/s . According to thermodynamic theory flexibility and limitation of the absorption reaction was analyzed and calculated. The results showed that the removal efficiency of SO₂ and NO_x reaches 100% nearly in the process of simultaneous desulfurization and denitrification from flue gas using urea additive. In the process of simultaneous desulfurization and denitrification from flue gas using urea solution, the removal efficiencies of SO₂ and NO_x are enhanced by the additive. Several type additives, such as the organic amine, the organic acid, the halide, the phosphate, H₂O₂ and TiO₂, were probed. Ethylenediamine and phosphate of ammonia were found to be optimal additives. The two compounds were selected. In the process of simultaneous desulfurization and denitrification from flue gas using solution of urea additive selected, function of the additive, characteristic and kinetic equation and mechanism of the absorption reactions, and effect of operation parameters on the removal efficiency of SO₂ and NO_x were studied. The additives enhance the removal efficiency of SO₂ and NO_x by buffering and catalyses. In urea solution absorption process...