Removal of Volatile Organic Compounds from Coal-Fired Power Plants Using Nonthermal Plasma Generated by a Dielectric Barrier Discharge Reactor: Carbon Yield and Application Feasibility

A nonthermal plasma (NTP) generated by a dielectric barrier discharge (DBD) reactor was used to purify a number of volatile organic compounds (VOCs) commonly found in power plant flue gases, and DBD and selective catalytic reduction (SCR) catalysts (V2O5/WO3/TiO2) used in power plants to reduce NOx emissions were combined to improve the removal performance of toluene and the CO2 yield. The removal efficiency and carbon yield for toluene and a mixture of VOCs (benzene, toluene, and m-xylene) were evaluated by varying the composition of the test flue gas and the input power. The presence of water promoted the removal of toluene and the generation of CO2. However, increasing the water content (>4%) or SO2, inhibited the removal of toluene since the presence of water or SO2 suppresses the discharge of the energy generated by the DBD reactor and consumes the reactive species. Zones I and II were identified using the plot between the VOC removal efficiency as a function of the input power in our study, and the intersection point was the optimal power. At 25 W, the postcatalytic process of an SCR catalyst combined with NTP resulted in an improvement in CO2 yield from 52.9 to 75.3% and a VOC removal efficiency above 98%. In practice, comparable improvements can be achieved by locating the NTP process in a power plant between the second layer and the third layer of the catalyst in an SCR unit.