Decomposition of indoor VOC pollutants using non-thermal plasma with gas recycling

Abstract

Volatile organic compounds in the indoor environment of small businesses (painting workshops, hair salons, nail shops, printing shops, laundries etc.) may result in adverse health effects for both workers and customers. Similarly, VOCs identified in these small businesses are included in the list of ozone precursors that harm the environment. We used a non-thermal plasma reactor with gas recycling to study the decomposition of dilute concentrations of VOCs in air. The non-thermal plasma reactor was a surface dielectric barrier discharge (surface DBD) type, and the target gases were methyl ethyl ketone, toluene and n-hexane at concentrations of 20, 50 and 100 ppmv. Highest decomposition efficiency (97%) was achieved by treating n-hexane at 20 ppmv. Gas recycling had an almost negligible effect during pollutant treatment at varying recycling rates (0-50%). Increasing the input energy resulted in higher decomposition efficiency, but had an inverse effect on the energy yield of the system. Concentrations of CO2 and ozone increased linearly with the increase of energy input in the system. Consumption of ozone for other applications, such as water treatment or coupling the DBD system with an appropriate catalyst, may address this concern.