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

引言 室内空气中的挥发性有机化合物(VOCs),如甲醛(HCHO)、苯(C<,6>H<,6>)、甲苯(C<,7>H<,8>)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.

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

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.