超富集植物热解中氯对重金属迁移特性的影响

Effects of chlorine on heavy metals migration during pyrolysis of hyperaccumulator biomass

为了研究超富集植物热解中氯对重金属迁移特性的影响,该文考察了在管式反应炉上N2气氛中,不同温度下无机氯(NaCl)和有机氯(PVC)的加入对重金属迁移特性的影响。结果表明,无论NaCl,还是PVC,都将增加重金属的挥发。对于Cd、Pb,有机氯的影响大于无机氯,而对于Zn、Mn和Cu,NaCl添加剂对其挥发特性比PVC添加剂的影响大。除Cd外,在400～700°С温度范围内,相同含量氯下重金属的挥发随温度的升高变化不大,只有700°С以上挥发率的差别比较明显。在温度为900°С时,不论是否加入氯,Cd、Pb和Zn的挥发率都达到100%。在试验范围内,Mn和Cu的最大挥发率为66.15%和66.99%,底渣中Mn和Cu含量较多。

Effects of chlorine on heavy metals migration at different temperatures were studied in a quartz tube under nitrogen atmosphere by adding inorganic chloride（NaCl） and organic chloride（PVC） during pyrolysis of hyperaccumulator biomass.The results indicated that NaCl or PVC additives could make an increase of heavy metals evaporation.For Cd and Pb,the PVC had much more impact on heavy metals migration characteristics than NaCl.For Zn,Mn and Cu,the order was contrary.The results also indicated that,excepting Cd,in the same chlorine content conditions,the heavy metals evaporation had no large change with the temperature increased from 400 to 700 °С.Only at higher temperature（above 700°С）,the distinction could be detected.At the temperature of 900°С,Cd,Pb and Zn were volatile completely whether chlorine were added or not.In the experimental range,the maximum evaporation rate of Mn and Cu were 66.15% and 66.99% respectively,leading to higer Mn and Cu contents in bottom ash.