低温等离子体联合光催化技术降解甲苯的实验研究

Decomposition of toluene by non-thermal plasma coupled with catalyst

采用低温等离子体联合光催化技术降解甲苯,从电压、电源频率、甲苯气体流量、初始浓度和Mn2+掺杂量等方面考察其对甲苯降解率的影响,并对比γ-Al2O3、TiO2/-γAl2O3和Mn1.0/TiO2/-γAl2O3(Mn2+摩尔分数为1.0%)3种填料的甲苯降解能量利用效果。结果表明,在相同电压和频率条件下,3种填料的甲苯降解率依次为Mn1.0/TiO2/γ-Al2O3>TiO2/-γAl2O3>γ-Al2O3,Mn1.0/TiO2/-γAl2O3填料的甲苯降解率最高可达98.77%;对于甲苯气体流量和初始浓度的增加,低温等离子体联合光催化技术具有很好的缓冲能力,当气体流量由1.5 L/min提高到3.0 L/min时,Mn1.0/TiO2/γ-Al2O3填料的甲苯降解率仅下降0.97百分点;Mn2+存在最佳掺杂量,Mn1.0/TiO2/-γAl2O3的甲苯降解率优于Mn0.5/TiO2/-γAl2O3(Mn2+摩尔分数为0.5%)和Mn1.5/TiO2/-γAl2O3(Mn2+摩尔分数为1.5%);在能量效率方面,Mn1.0/TiO2/-γAl2O3填料比γ-Al2O3、TiO2/-γAl2O3填料分别提高了99.7%和16.9%。

Decomposition of toluene by non-thermal plasma coupled with photocatalyst was performed in a lab scale packed tower batch reactor,the effects of applied voltage,power frequency,gas flow rate,initial toluene concentration and different Mn^2＋ doping amount on toluene decomposition efficiency were investigated.Furthermore,the energy efficiency of 3 padding（γ-Al2O3,TiO2/γ-Al2O3 and Mn1.0/TiO2/γ-Al2O3） was compared.The result showed that Mn1.0/TiO2/γ-Al2O3 was the most effective padding for toluene decomposition;under the same applied voltage and power frequency,the decomposition efficiency of three padding followed the order of ηMn1.0/TiO2/γ-Al2O3ηTiO2/γ-Al2O3ηγ-Al2O3,and the maximum value of ηMn1.0/ TiO2/γ-Al2O3 could reach 98.77%.This combined technology presented excellent buffer capability against increasing gas flow rate and initial toluene concentration,when the gas flow rate increased from 1.5 L/min to 3.0 L/min,the drop of ηMn1.0/ TiO2/γ-Al2O3 was only 0.97%.The best doping rate of Mn^2＋ was 1.0%.Compared with γ-Al2O3 and TiO2/γ-Al2O3,the energy efficiency of Mn1.0/TiO2/γ-Al2O3 was increased by 99.7% and 16.9% respectively.