Micro-Nano Bubbles,Additives Coupling Spray Method Simulataneous Desulfurization And Denitrification Research

The emission of SO₂ and NO_X causes environmental problems such as photochemical smog,global warming and acid rain,especially the NO in NO_X,some of which are as high as 95%and are difficult to dissolve in water and are difficult to remove.Common simultaneous desulfurization and denitrification methods generally include plasma method,microbial method,catalytic method,absorption method and adsorption method,etc.The spray method with spray tower as the main equipment is characterized by its simple equipment,low resistance,low investment cost,and low operating cost,and this method of using Ca SO₃ as an absorbent is a wet desulfurization method widely accepted by the market.As far as spraying is concerned,although it has a certain removal efficiency for SO₂,the effect on NO production is not ideal.Therefore,an oxidation method is introduced to improve the removal rate of NO_X.Common oxidants include perchlorate,permanganate and ozone,etc.while micro-nano bubbles can spontaneously produce a large amount of·OH when they collapse in water,that is,the micro-nano bubble aqueous solution is an oxidant with high oxidizing ability,which is beneficial to the removal of SO₂ and NO_X without secondary pollution.Based on the characteristics of micro-nano bubbles and sprays,this paper studies the coupling of the two are used to absorb and remove SO₂ and NO_X in flue gas.Furthermore,on the basis of spraying and micro-nano bubbles,additives are introduced to study different additives and their concentrations to improve the removal rate of NO_X.Under the best conditions,use the industrial absorption liquid to carry out the particulate matter experiment and the double-tower experiment to improve the removal rate of NO_X again.The experimental results are as follows:（1）Using the spray-coupled micro-nano bubble dispersion system in the absorption tower,the SO₂ concentration in the flue gas is 1142 mg/m³,and the NO_X concentration is 1000 mg/m³,when the reaction stabilization time is 120s,the p H of the aqueous solution is 5,and the water temperature at 20°C,the micro-nano bubble dispersion system accounts for 50%of the entire spray water solution,the immersion depth is 50cm,the air volume is 60L/min,the spray water volume is3.3L/min,the filler height is 120cm,and the SO₂ removal rate is up to 98.72%,NO_X removal rate rose from about 20%to 70.45%,the effect is remarkable.（2）The desulfurization and denitrification experiments were carried out using micro-nano bubbles,additives coupling spray method.The results showed that the removal rate of NO_X first increased and then decreased with the increase of Fe SO₄·7H₂O concentration,and when the concentration is 0.25mmol/L,the removal rate of NO_X the maximum removal rate of NOX is72.64%;the removal rate of NO_X first rises and then decreases with the increase of Mg SO4·7H2O concentration,and when the concentration is 1.5mmol/L,the maximum removal rate of NO_X is78.72%;the removal rate of NO_X first increased and then decreased with the increase of Na Cl concentration,and when the concentration of Na Cl is 0.2g/L,the maximum removal rate of NOX is 68.81%;the removal rate of NO_X first increased and then decreased with the increase of urea concentration,and when the urea concentration is 2%,the maximum removal rate of NO_X is 75.52%;when the concentration of Ca（OH）₂ is 3mmol/L,the maximum removal rate of NO_X is 75.78%;Mn SO₄·H₂O and SDS as a single factor,as the concentration increases,the removal rate of NO_Xwill decrease,which will inhibit it;the removal rate of SO₂ by all single factors has been stable above 95%,with little fluctuation.Under the optimal conditions,that is,when the p H is 5,the Mg SO₄·7H₂O concentration is 1.5mmol/L,the urea concentration is 2%,and the Ca（OH）₂concentration is 3mmol/L,the removal rate of NO_X is 88.34%and that of SO₂ The removal efficiency is 99.05%,the effect is the best.（3）The solid components in the industrial absorption liquid used in this article are mainly Ca SO₃,and the liquid mainly contains magnesium ions and calcium ions,which can promote the removal of SO₂ and NO_X.Under the optimal conditions of the reaction,using this absorption solution for experiments,the removal rate of SO₂ is 98.22%,and the removal rate of NO_X is 84.68%;after the number of cycles of absorption of the absorption solution increases,the removal rate will decrease to a certain extent;again;After adding particulate matter,the removal rate of SO₂ rises to98.73%,and the removal rate of NO_X rises to 89.03%;once again a series absorption tower is added,the removal rate of SO₂ is 99.64%,and the removal rate of NO_X is 91.54%.