Abatement of gas-phase VOCs via dielectric barrier discharge plasmas

Abstract

Non-thermal plasma (NTP) technology is regarded as promising method for abatement of volatile organic compounds (VOCs) and has gained substantial interests in the fields of air purification. In this present work at atmospheric pressure, dielectric barrier discharge (DBD) plasma has been employed and utilized to evaluate feasibility of toluene, benzene, and m-xylene degradation in a parallel plate type DBD reactor taking argon as a carrier gas. The composition of post-plasma-treated by-products is studied by various spectroscopic techniques such as GC, GCMS, and FTIR, and the corresponding computational work is carried out by Gaussian software. The by-products obtained are analyzed in order to ascertain their structure and stability. The degradation of the VOCs to CO and CO₂ has been affirmed from the GC and GCMS analyses. Furthermore, the probable degradation pathway for the degradation of the aforementioned VOCs has been deciphered and the most feasible path is suggested. Additionally, DFT calculations have been performed to have an idea about the energies of the pathways involved. This research work has been carried out without use of any catalyst. Surprisingly, the degradation observed is much higher than the reported values. These findings would be helpful towards the abatement of VOCs by the use of non-thermal plasma.

Keywords: Dielectric barrier discharge (DBD); Gas chromatography (GC); Gas chromatography mass spectrometry (GCMS); Non-thermal plasma; Volatile organic compounds (VOC).