Plasma reforming of tar model compound in a rotating gliding arc reactor: Understanding the effects of CO2 and H2O addition

Abstract

In this study, a rotating gliding arc (RGA) plasma reactor co-driven by a magnetic field and tangential flow has been investigated for the reforming of toluene as a tar surrogate from the gasification of biomass or waste. The effect of steam and CO2 addition on the reaction performance of the plasma tar reforming process has been evaluated in terms of the conversion of toluene, gas production and energy efficiency. The presence of CO2 in the reaction suppresses the conversion of toluene. By contrast, adding an appropriate amount of steam to the reforming process significantly enhances the conversion of toluene, while further increasing steam concentration reduces the conversion of toluene. The maximum toluene conversion of 85.2% is achieved at an optimal steam concentration of 16%. Optical emission spectroscopic (OES) diagnostics have been used to understand the generation of reactive species contributed to the conversion of toluene and reaction intermediates in the plasma reforming process. The possible reaction pathways and mechanisms have been discussed based on the analysis of gases and condensed liquid by-products combined with the emission spectra of the plasma in the presence or absence of steam and CO2.