固定床PVC燃烧脱氯的机理和试验

Experimental and Mechanism Analyses on HCl Emission Control during PVC Combustion in Fixed Beds

研究垃圾组分PVC在焚烧过程中HCl的排放和脱除特性的实验在准等温、电加热的水平石英管反应器中进行 .随着床温从 70 0℃升高到 90 0℃ ,HCl的转化率从 82 5%平缓增加到 88 3% ,而过量空气系数的增加促使部分HCl转化为Cl2 ( 1 9%～ 4 5% )的形式存在 .钙基吸收剂CaCO3,Ca(OH) 2 ,Ca(CH3COO) 2 对HCl的脱除效率高达 68%～ 79% ,而镁基吸收剂的脱氯效率却低于 3% .小的吸收剂粒径、高的Ca/Cl比会促进脱氯效率的提高 ;烟气中CO2 和H2 O对脱氯效率的影响与它们在反应平衡中所起作用有关 .高温下燃烧固氯机理反应的平衡常数的计算不仅诠释了实验结果 ,而且提供了脱氯吸收剂选择的依据 .

Incineration of chloridated plastic (PVC) in solid wastes contributes much to HCl pollutant in air environment.The characteristics of HCl emissions and reduction during PVC combustion were conducted in a nearly isothermal, externally heated, horizontal quartz\|tube reactor. With increasing temperature from 700 to 900℃, the conversion of HCl increased leniently from 82 5% to 88 3%. High excess air factor enhanced a small amount of HCl existing in form of Cl 2. The calcium based sorbents including CaCO 3, Ca(OH) 2, Ca(CH 3COO) 2 exhibited high HCl capture efficiencies from 68% to 79%, while magnesium based sorbent less than that of 3%. Influences of operational variables, i.e., size of sorbent, Ca/Cl molar ratio and combustion fume compositions, on the HCl reduction were discussed. From a point of view of equilibrium constant of dechloridization reaction the experimental results were explained in detail.