Study On The Performance Of Coke Powder/Activated Carbon-Porous Alu Mina Synergistic Purification Of Asphalt Smoke

Aiming at the problems of the secondary treatment of the adsorption filter medium and dust caused by friction between each other in the asphalt smoke adsorption filter device of the carbon factory,combined with the production process of the electrode paste of the carbon factory,a coke powder/activated carbon porous alumina synergistic purification technology for asphalt smoke is proposed,and its purification performance was studied.The effect of temperature on the components of asphalt smoke,polycyclic aromatic hydrocarbons(PAHs)and their toxicity was studied by GC-MS.It is found that asphalt smoke is mainly composed of aromatic hydrocarbons.The aromatic hydrocarbons are mainly 3～4 ring aromatic hydrocarbons such as phenanthrene,anthracene,fluoranthene,pyrene and benzo(a)anthracene without substituents,and the substituents are distributed on the 2～3 ring aromatic hydrocarbons in the form of methyl and dimethyl.With the increase of temperature,the proportion of PAHs priority control by EPA in the asphalt smoke decreases,the equivalent concentration and the toxic equivalent concentration are greatly increased,and the equivalent concentration is dominated by 3～4 ring PAHs,the toxic equivalent concentration is dominated by 5 ring PAHs.The effects of filter thickness,particle size,gas velocity and smoke temperature on coke powder and activated carbon were studied by fixed bed experimental device.When the thickness of the filter medium is greater than 30 mm,the particle size is less than 2mm,the gas velocity is less than 0.2 m/s and the flue gas temperature is less than 50 ℃,coke powder and activated carbon can reduce the PAHs equivalent concentration of 3ring and above in asphalt smoke by more than 90 %,while the toxic equivalent concentration can be reduced by more than 95 %.The Langmuir isotherm adsorption model was used to analyze the adsorption kinetics of naphthalene on coke powder,activated carbon and porous alumina.It is found that the adsorption isotherm of naphthalene on coke powder,activated carbon and porous alumina conforms to the Langmuir adsorption isotherm equation,and the adsorption kinetics can be described by Langmuir.Adsorption thermodynamics research shows that the adsorption of naphthalene on coke powder,activated carbon and porous alumina is an exothermic process,and low temperature is conducive to the adsorption of naphthalene.The effects of filter medium size,filter medium thickness and filter gas velocity on the collection efficiency of asphalt smoke were studied.It is found that when the filter medium size is 3～5 mm and the filter medium thickness is 15 cm,the filter gas velocity increases from 0.1 m/s to 0.5 m/s.The collection efficiency of coke powder and activated carbon on asphalt smoke decreased from 95.5 % to 89.3 % and 96.8 % to 91.3 %,and the resistance increased from 47 Pa to 145 Pa.When coke powder and activated carbon and porous alumina synergistically collect asphalt smoke,collection efficiency can be increased by 3 % to 7 %.