Polycyclic Aromatic Hydrocarbons In The Coal Combustion Process To Generate The Mechanism And Control Of Experimental Research

Among those special contaminants from coal burning, the emission of the polycyclic aromatic hydrocarbons(PAHs), one of bio-contaminants, has already become a new preceding hotspot research field. Owing to their latent harm to the environment, increasing attention of the public was focused on the movement and control discipline of them. At the same time, the pollution problem inevitably caused by coal combustion has also drawn more and more attention of our government at different levels. The study in this paper was focused on the emission and control of PAHs from coal burning, which was generally thought as one of key components of air pollution.In this article, the relation between the PAHs and coal bank, fixed carbon and volatile was analyzed at first, and results indicated emission of PAHs decreased when fixed carbon increased or volatile decrease. Then, some experiments concerning PAHs from coal combustion were done in the fixed bed reactor, and the emissions or TEQ(toxic equivalent quantity)of PAHs was discussed at dfferent combustion temperature, combustion time, chloride content in coal and pyrolysis in N2. Be based on it, the combustion model of fixed bed and the mechanism of PAHs was analyzed. Futhermore, some experiment about the emissions or TEQ of PAHs was also studied at different combustion temperature, residence time, air flow, excessive air coefficient and Ca/S molar ratio in small scale FB(fluid bed). At the same time, the control of emissions of PAHs was analyzed when the secondary air was injected into the combustor in FB. Formation of PAHs was restrained by adding appropriate secondary air. At last, the effect of metal or metal-oxide on PAHs was studied. And ferric oxide and cupric oxide had more stimulation to the formation of PAHs than iron and copper. In this article, PAHs emissions from coal fired (pulverized coal) power stations were studied, andresults showed effect of temperature of exhausted gas on PAHs was more than boiler capacity.Moreover, removed of PAHs on wet scrubber and electrostatic jrecipitator was compared, and wetscrubber has good removal effect for PAHs.In order to be convenient for the model research of PAHs formation, emission, and control during the process of coal combustion or municipal waste and coal co-combustion in next stage, systemic discussion was taken on development situation and trend at abroad and home. In addition, some tentative plans were proposed for the research of next stage.