Abstract:

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.