Study On Removal Of SO₂ And No By Micro-nano Bubbles Gas-liquid Dispersion System

In the sintering process,a large amount of pollutants such as SO₂ and NO will be generated,which will bring great harm to the environment in which we live.With the promulgation of the latest pollutant emission standards,the emission reduction of SO₂and NO_X has become the focus in the future period of time.At present,limestone-gypsum and carbon-based materials are widely used for desulfurization,and the rate is above 90%.For the removal of NO,the selective catalytic reduction method is mainly used,which can achieve a denitrification rate of 90%.Selective catalytic reduction?SCR?method used for denitrificationcan which can also achieve a removal rate of 90%.Simultaneous removal of SO₂ and NOx has become a hot topic due to its advantages such as simple process,less equipment,and small footprint.At present,the simultaneous desulfurization and denitrification technologies include activated carbon adsorption,urea,and complex absorption.The desulfurization rate can reach over 90%,but there is still much room for improvement in denitrification.In this paper,the efficiency of simultaneous absorption of SO₂ and NO by the micro-nano bubbles gas-liquid dispersion system was investigated based on the study of the oxidation and absorption of NO in the earlier stage of the research group.SO₂in the flue gas can promote the absorption of NO by the micro-nano bubbles gas-liquid dispersion system.The effects of various factors on the desulfurization and denitrification of the micro-nano gas-liquid dispersion system were studied,and the mechanism of micro-nano bubble oxidation and absorption NO was obtained.Some achievements have been made:?1?The micro-nano bubbles gas-liquid dispersion system could promote the absorption of NO mainly because the micro-nano bubbles generate hydroxyl radicals when they break,which can oxidize NO to NO₂,thereby increasing the NO absorption efficiency.?2?SO₂,metal catalysts,pH,salinity,and surfactants had an effect on the removal of NO with the removal of SO₂ and NO by air/H₂O/micro-nano bubbles gas-liquid dispersion system.The addition of SO₂ in the denitration system promoted the absorption of NO,the amount of SO₂ intake was different,and the removal rate of NO increased in different degrees.Different catalysts had different effects on the absorption of NO.The effect of Mn²⁺was best by comparing the promoting ability of Fe²⁺,Mn²⁺,and Mg²⁺ions on NO absorption efficiency.When the concentration of Mn²⁺was 2 mmol/L,the denitration efficiency in the system was increased by 17%compared to the case without Mn²⁺.Under optimal conditions:pH was 5,NaCl concentration was 0.5 g/L,SDS concentration was 4 mg/L,and Mn²⁺concentration was 2 mmol/L,SO₂ and NO removal rates were 100%and 96.19%,respectively.?3?The simulated flue gas was mixed with O₃,H₂O,NO,and SO₂ to produce micro-nano bubbles,and the integrated desulfurization and denitrification was performed.When the NO concentration increased to 5000 ppm and the SO₂concentration increased by 6250 ppm,SO₂ could still be completely absorbed,and NO reached over 85%of absorption.When[O₃]/[NO]was less than 1,with the increase in[O₃]/[NO],the desulfurization and denitrification rate could be significantly increased.When the pH of the solution was too low or too high,the NO absorption rate would decrease,and the SO₂ absorption efficiency wouldl only decrease under strong acid conditions.When the concentration of NaCl in the solution was 0.5 g/L,the desulfurization and denitrification rate could reach 100%and 79.29%,respectively.When the catalysis of Mn²⁺concentration was 2 mmol/L,with the increase of SDS in the solution,the absorption efficiency had a process of increasing first and then decreasing.