Removal Of NO_x From Flue Gas By Yellow Phosphorus Composite Slurry

With the continuous increasing of population and the improvement of people's living standard,the contradiction between economic growth and environmental protection is becoming more and more serious.Especially in recent years,fog and haze is rampant,which has seriously affected people's normal life and brought great threat to people's health and the environment living.The excessive emissions of NOx is one of the culprits causings for fog and haze forming.So the governance of NOx is imminent.Therefore,China has continued to upping the emission reduction standards about NOx,and proposed to achieve the ultra low emission targets of 50 mg/m3.In order to meet the increasingly stringent environmental emission requirements,improving the denitration efficiency,as well as reducing denitration cost is one of the most important contents in air pollution control now.In this paper,yellow phosphorus was used as oxidant.The research focused on the denitrification process of the absorption liquid composited by yellow phosphorus and phosphate pulp,and the conditions and mechanism of producing ozone by the reaction of yellow phosphorus and oxygen.The purpose of this paper was to combine the existing phosphate pulp wet desulfurization technology,and to realize the simultaneous desulfurization and denitrification in the phosphate chemical industry in the future.The following conclusions were obtained:(1)The effects of various experimental factors on the denitrification of the absorption liquid composited by yellow phosphorus and phosphate pulp were investigated,and found that the denitrification rate of slurry system increased with the increase of phosphorus concentration,slurry pH,oxygen content and stirring speed.The denitrification rate increases with the increase of the slurry temperature and the solid content of the slurry,and then decreases after reaching the extreme value,the optimum temperature and solid content was 65?,9.09%respectively.The denitrification rate decreased with the increase of NOx inlet concentration and gas volume.According to the experimental results,the suitable experimental conditions were the concentration of yellow phosphorus 1.6 g/L,the slurry pH controlled more than 3.76,the slurry temperature 65 ?.the slurry contains solid content 9.09%,the oxygen concentration 6%,and the flue gas flow rate 535 mL/min.(2)Based on the response surface optimization experiment,the effects of P4/NOx,slurry temperature,slurry pH and gas volume on the denitrification efficiency and the interaction between them were analyzed.The impact degree of each factor on the slurry denitrification rate from strong to weak was P4/NOx,slurry temperature,gas volume,and slurry pH,hereing P4/NOX,slurry temperature,gas volume,the quadratic term of P4/NOx and slurry temperature,the interaction terms of P4/NOx and slurry temperature,the interaction terms of slurry temperature and gas volume,and the interaction terms of P4/NOx and gas volume had significant effect on the slurry denitrification rate.(3)The regulation of the formation of ozone in the absorption solution was studied.It was found that the high stirring speed and the concentration of yellow phosphorus were beneficial to the formation of ozone.With the increase of slurry temperature,the ozone concentration increased first and then decreased,the optimum temperature was 65?;different dispersion media had a very different effect on the formation of ozone,mainly due to their different particle size and particle surface appearance.Further study showed the reaction of yellow phosphorus and oxygen to generate ozone mainly occured in the liquid phase,which was gas-liquid contact reaction.