流态化TiO_2光催化降解甲苯的实验

在自制的流化床反应器中,以实验室制备的TiO2/硅胶为催化剂,对甲苯、空气混合气进行光催化降解,探讨了初始浓度、紫外光强度、操作气速和床层高度等因素对甲苯降解率的影响。实验结果表明:在低浓度范围内(20~55mg/m3),甲苯降解率不随浓度变化,高达100%,但浓度进一步增加后降解率下降;甲苯降解率随紫外光强度的增加而提高,但提幅不大;甲苯初始浓度越低,维持最高降解率的时间越长;操作气速存在最佳值3·98cm/s,达到此值时降解效果最好;甲苯降解率随床层高度(静态高度)的增加而线性提高。

PHOTOCATALYTIC DEGRADATION OF TOLUENE BY TiO2 IN A FLUIDIZED-BED

In a self-made fludized-bed,TiO_2/silica gel prepared in laboratory was used as photocatalyst to degrade toluene-air mixed gas.The effect of operating parameters including initial concentration.UV light intensity,operating gas velocity and bed height(stable height)on degradation rate of toluene was probed into in this research.The results show that the degradation rate of toluene didn't change with concentration,reaching 100%,under low concentration level (20～55 mg/m~3);but decreased with higher concentration.The degradation rate of toluene increased slightly with stronger UV light intensity.The lower the initial concentration was,the longer the highest degradation rate could be sustained for.And there was a best gas velocity value 3.98 cm/s,degradation rate reached the maximum value under this circumstance.The results also show that the degradation rate of toluene increased linearly with increase in bed height.