Tar Removal by Nanosecond Pulsed Dielectric Barrier Discharge

Plasma-catalytic reforming of simulated biomass tar composed of naphthalene, toluene, and benzene was carried out in a coaxial plasma reactor supplied with nanosecond high-voltage pulses. The effect of Rh-LaCoO3/Al2O3 and Ni/Al2O3 catalysts covering high-voltage electrode on the tar conversion efficiency was evaluated. Compared to the plasma reaction without a catalyst, the combination of plasma with the catalyst significantly enhanced the conversion of all three tar components, achieving complete conversion when an Rh-based catalyst was used. Apart from gaseous and liquid samples, char samples taken at five locations inside the reactor were also analyzed for their chemical composition. Char was not formed when the Rh-based catalyst was used. Different by-products were detected for the plasma reactor without a catalyst, with the Ni- and Rh-based catalysts. A possible reaction pathway in the plasma-catalytic process for naphthalene, as the most complex compound, was proposed through the combined analysis of liquid and solid products.