循环的存储-放电等离子体催化新过程脱除室内空气中甲苯

Cycled storage-discharge plasma catalytic process for toluene removal from indoor air

引言室内空气中的挥发性有机化合物（VOCs）,如甲醛（HCHO）、苯（C6H6）、甲苯（C7H8）等,是一类对人体有极大危害的室内空气污染物[1-2]。传统的脱除VOCs的方法有吸附法、催化氧化法、热焚烧法等，这些方法在经济上或处理效率上或多或少存在缺陷。用于室内空气中VOCs脱除的理想方法应该同时具备脱除效率高、室温脱除、操作简单、能耗低及无二次污染物等特点。

Non-thermal plasmas（NTPs）technique has a great potential for indoor air purification,however,the high energy cost and secondary pollutants formation limit its practical application.To resolve these problems,a cycled storage-discharge（CSD）plasma catalytic process was explored for the removal of low-concentration toluene from indoor air in this study.The performance of toluene storage and plasma catalytic oxidation of adsorbed-state toluene over non-loaded and silver-loaded HZSM-5 catalysts was investigated.The experimental results showed that silver-loaded HZSM-5 catalysts gave a longer breakthrough time than non-loaded HZSM-5 catalysts at the storage stage（storage condition： 0.1 g·m-3 C7H8,40% relative humidity（RH,25℃）,2000 ml·min-1 flow rate of simulated air）.With input power of 40 W,the adsorbed-state toluene could be almost oxidized to CO2 in 10 min at the discharge stage（carbon balance about 100%,CO2 selectivity 98.2%）.It was further proved that there was no toluene desorbed during the process of plasma catalytic oxidation by on-line detection with mass spectrometry（MS）and Fourier transform infrared spectrometry（FTIR）.Preliminary investigation on the stability of the CSD process for toluene removal was conducted.This study provides a novel plasma catalytic process for removing toluene from indoor air.