微波场中催化剂对甲苯废气的氧化分解研究

Oxidation decomposition of toluene waste gas by catalyst in microwave field

为减少挥发性有机化合物所造成的污染,改善大气环境质量,探究微波催化氧化甲苯废气技术的实际应用,采用传统浸渍法,制备具有尖晶石结构的铜锰铈负载型催化剂,利用X射线衍射、扫描电子显微镜和氮气吸附法等检测方法对该催化剂进行表征.利用本课题组自行研制的微波净化设备,研究在微波场-催化剂协同催化的作用下,负载型催化剂对氧化分解甲苯的催化性能,探究各种不同工艺参数条件下的催化效果.表征表明,该铜锰铈催化剂表面的尖晶石相CuMn_2O_4对挥发性有机物(volatile organic compounds,VOCs)有较高的催化氧化活性.催化实验结果表明,600℃条件下焙烧制成的铜锰铈催化剂具有明显的低温催化氧化特性,在微波功率为400 W、反应温度为280～350℃、空间速度(单位时间、单位体积催化剂上通过的标准状态下反应器气体的体积)为1 400～5 600 h^(-1)、甲苯的质量浓度为7. 5～30. 0g/m3的条件下,对甲苯的去除率可超过90%.且对于甲苯的去除具有较强的抗冲击能力;在100 h的稳定性实验过程中,催化效率均保持在90%以上,稳定性很好,具有良好的应用前景.

In order to reduce the pollution caused by volatile organic compounds and improve the atmospheric environment quality,the practical application of microwave catalytic oxidation of toluene waste gas was explored.This copper manganese cerium supported catalyst with spinel structure was prepared by traditional impregnation method.The catalyst were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM)and the nitrogen adsorption method.The results suggest that CuMn 2O 4 on the catalyst surface improved catalytic oxidation activity.The catalyst prepared at calcination temperature of 600℃showed the best catalytic oxidation activity.Over 90%toluene removal rate is achieved in the microwave-catalyst reactor under conditions of a minimum reactor temperature of 280-350℃,microwave power of 400 W,“space velocity”(that is volume of reaction gas through unit volume catalyst in unit time)of 1 400 to 5 600 h-1 and toluene inlet concentration of 7.5 to 30.0 g/m 3.The toluene influent concentrations loading has minor effect on the reactor performance.This catalyst also shows great stability:the catalytic efficiency maintains was kept above 90%in the process of 100 h stability experiment.In general,the toluene removal method has promising application potentials.