Biomass gasification tar removal using dielectric barrier discharge reactor: Effect of reactor geometry and carrier gases

This study investigates the impact of reactor geometry (varying external electrode length) of Dielectric Barrier Discharge (DBD) reactors on the decomposition of toluene, a model compound for biomass gasification tar, using different carrier gases and various power levels. Results reveal that toluene decomposition is higher at longer electrode lengths (30 mm) at all power levels tested. Specifically, the toluene decomposition in H₂ carrier gas at 30 mm electrode length increased from 67.2 % to 97.5 % with rising power from 5 to 40 W, while it ranged from 52 % to 97.4 % at 15 mm electrode length. The decomposition of toluene was found to be higher in N₂ carrier gas than in H₂ carrier gas at both discharge lengths. At 30 mm external electrode and with rising power from 5 to 40 W, toluene decomposition ranged from 90.5 % to 98.7 %. Similarly, when the electrode length was reduced from 30 to 15 mm for N₂ carrier gas, the decomposition of toluene ranged from 74 % to 97.9 %. Thus, the results indicate that the decomposition of toluene is affected by both the electrode length and the nature of the carrier gas. The effect of electrode length was significant at lower power levels, and the difference between the conversion at both electrode lengths nearly disappeared at higher power levels.