Activated Carbon Injection Coupled With Power Plant Dust Collector To Synergistically Remove Organic Pollutants/Mercury/CPM From Coal-Fired Flue Gas

With the improvement of China’s environmental protection requirements,organic pollutants and mercury in coal-fired flue gas have gradually become the focus of emission control.With the implementation of ultra-low emissions in power plants,the pollution of filterable particulate matter pollution of coal-fired power plants has been basically solved,and the condensable particulate matter has not yet been effectively controlled,and has gradually become the focus of research.This thesis explores the synergistic removal effect of activated carbon injection coupled with power plant dust removal equipment for the above three pollutants,explores the adsorption removal characteristics of the three pollutants,and provides an experimental data basis for future industrial applications.Activated carbon injection coupled with bag dust removal simulation test platform tested the characteristics of activated carbon injection technology on the removal of simulated coal flue gas,and studied the effects of organic matter properties,activated carbon pore structure and flue gas components on the efficiency of organic matter removal.The results show that the boiling point of the adsorbate is the main factor that affects the removal efficiency of the ACI+BF process.The removal efficiency of organics with high boiling point is higher,and the pore structure of the adsorbent is the main influencing factor.High specific surface area and larger pore volume are conducive to the adsorption of organic matter.Water vapor will reduce the removal efficiency of organic matter by the ACI+BF process;low mass concentration coal-fired fly ash reduces the removal efficiency,high mass concentration fly ash is conducive to the formation of a more complete activated carbon filter layer,and the removal efficiency decreases less;inhibition of SO₂ is not strong,as the mass concentration increases,the inhibitory effect is strengthened;when multiple components coexist,the removal efficiency of organic matter is the lowest,about 47.13%.Through the 1200Nm³/h thermal coal-fired organic matter emission control test,the concentration of organic matter in the actual coal-fired flue gas was tested,and the removal characteristics of VOCs,SVOCs and CPM organic components were also studied.The results show that the actual coal-fired flue gas organic matter concentration is about 13mg/m³,and VOCs are the main existing form of gaseous organic matter.When spraying unmodified activated carbon,the highest total organic matter removal efficiency is 59.97%;the removal efficiency of activated carbon spraying on SVOCs is higher than that of VOCs,while the removal efficiency of organic components of condensable particles is the lowest.When modified activated carbon sprayed,the removal efficiency of organic matter has been improved,and the removal efficiency of nitric acid modification is the best.The total hydrocarbons,VOCs,SVOCs,and CPM organic components have the same changing trend when activated carbon is sprayed.It can be explained that the reduction of CPM organic components is caused by the adsorption of gaseous organic matter by activated carbon.The tests carried out in coal-fired power plants mainly explored the characteristics of activated carbon injection coupled bag/electrostatic precipitator to remove organic pollutants,mercury and CPM from coal-fired flue gas.The results show that the total concentration of organic matter is low,and the concentration of organic matter is distributed between 0.517 and 2.584 mg/m³;the main organic matters are VOCs,and the concentration of SVOCs is low.Concentration of VOCs and SVOCs are not necessarily positively correlated;activated carbon injection has a significant removal effect on organic matter,and the removal efficiency of SVOCs is highest;the activated carbon injection volume is an important factor,when the injection volume increased from 50 mg/m³ to 150 mg/m³,the organic matter removal efficiency increases by 27.52%.The concentration of gaseous mercury after the bag/electrostatic precipitator is in the range of 13～20μg/m³;the removal efficiency of gaseous mercury by the precipitator is very low;the activated carbon injection has obvious effect on the removal of gaseous mercury.When the bag/electrostatic precipitator is coupled,the highest removal efficiency is 56.14%and 47.10%,respectively.The injection volume of activated carbon is an important factor affecting the removal efficiency of gaseous mercury.When the injection volume increases from 50 mg/m³ to 150mg/m³,the removal efficiency increases by 31.09%.After the bag/electrostatic precipitator,the condensable particulate matter becomes the main particle pollutant;the bag/electrostatic precipitator has a lower removal effect on the condensable particulate matter,and the removal efficiency is 32.11%and 42.4%respectively;Inorganic components are the main component,and the mass of inorganic components accounts for more than 63.30%.The cations in the inorganic components are mainly sodium ions,while the anions are mainly SO₄^2-;activated carbon injection has a relatively obvious removal effect,the highest can reach 58.27%,and the concentration of SO₄^2-has been significantly reduced,indicating that activated carbon injection has a certain adsorption and removal effect on SO₃.Activated carbon injection will slightly increase the carbon content of fly ash.