Study On Simultaneous Desulfurization And Denitrification Of Mud-Phosphorous Slurry And Mass Transfer

SO₂ and NO_x,the main air pollutants emitted by industrial furnaces,seriously pollute the environment,and mud-phosphorus is a kind of solid waste containing elemental phosphorus,which is difficult to be processed by the yellow phosphorus enterprises.In view of this,this paper proposes a new technology to purify SO₂ and NO in industrial flue gas by wet catalytic oxidation with mud phosphorus slurry as absorbent without any other catalyst.To this end,this paper proposes a mud-phosphorus slurry as an absorbing solution,without adding any other catalyst,a new technology of removal SO₂ and NO in industrial flue gas using wet catalytic oxidation technology.At the same time,single-factor experiment and response surface optimization experiment were used to explore the influence of reaction temperature,gas rate,oxygen content and the ratio of solid to liquid of argillite emulsion on desulfurization and denitrification efficiency.Finally,the mass transfer process was explored.In the discussion of single-factor experiments,the results show that the simultaneous desulfurization and denitrification efficiency of mud-phosphorus slurry decreases with increasing gas flow rate;it increases with the solid-liquid ratio of mud-phosphorus slurry;when the temperature is from 25?to 60?,it increases with the increase of the reaction temperature,but decreases sharply at 70?.The desulfurization and denitrification efficiency increases significantly when the oxygen content increases from 0%to 30%,and decreases sharply when the oxygen content at40%.The optimal conditions for simultaneous desulfurization and denitrification of mud-phosphorus slurry were obtained?SO₂ concentration of 1500 mg/m³,NO concentration of 700 mg/m³,reaction temperature of 60?,mud-phosphorus slurry solid-liquid ratio of 5.0 g/40 mL,and oxygen content 20%,air flow rate 300 mL/min?.The desulfurization and denitrification rate under these conditions can reach more than 99%within 860 minutesThree factors and three levels of response surface experiments were performed on the reaction temperature,oxygen content,and solid-liquid ratio of the mud-phosphorus slurry for simultaneous desulfurization and denitrification.As follows:oxygen content>solid-liquid ratio of mud-phosphorus slurry>reaction temperature.The oxygen content has a highly significant effect on the efficiency of desulfurization and denitrification.The relationship between the simultaneous desulfurization and denitrification efficiency of mud-phosphorus slurry and the regression equation of each factor is significant and has statistically significant.The obtained simulation equation has a good correlation.Simultaneous desulfurization and denitrification of mud-phosphorus slurry aims to use the P₄ in waste mud-phosphorus to convert O₂ to O₃ and oxidize SO₂ and NO with O₃ to achieve the purpose of desulfurization and denitrification.Therefore,the influence factors of ozone production in slurry are investigated.It is concluded that the increase in the solid-liquid ratio of the mud-phosphorus slurry can increase the amount of ozone generated;when the temperature is between 25?and 60?,the ozone production amount increases significantly with the increase of temperature,and at 70?,the ozone production amount sharply increases.The optimum temperature is 60?,and the ozone production is the fastest when the oxygen content is 30%,and the maximum ozone production is the highest.Under the best experimental operating conditions?reaction temperature 60?,mud-phosphorus slurry solid-liquid ratio 5.0g/40 mL,oxygen content 30%,gas flow 200 mL/min?,the maximum ozone generation was 550.6 mg/m³.In the mass transfer kinetics of simultaneous desulfurization and denitrification of mud-phosphorus slurry,desulfurization is controlled by gas film,and denitrification is controlled by liquid film.When the temperature is between 298.15 K and 343.15 K,the gas phase mass transfer coefficients of SO₂ and NO,and the liquid phase mass transfer coefficients gradually increase with the increase of temperature,but the gas phase mass transfer coefficients of SO₂ and NO decrease at 343.15 K.