Combination of VOC degradation and electro-hydrodynamic pumping actions in a surface dielectric barrier discharge reactor

This paper concerns the study of a surface dielectric barrier discharge (SDBD) reactor designed for offering simultaneously chemical (VOC degradation) and mechanical (electro-hydrodynamic pumping) actions. It takes the form of a channel composed of active faces on which surface plasma is generated in AC sinusoidal mode with a resonant power-supply. The chemical application targeted is the flexible and low energy-cost abatement of VOC present in air at low concentration, which is a major current industrial concern for safety and environmental reasons. Regarding the mechanical action, the SDBD acts as a pump. It is able to induce flow rates reaching up to 153 L/min for a 60 W consumption with an electro-mechanical yield of 0.0133% in open configuration, while as any pump, it falls down in connected configuration; 39 L/min connected to our air treatment bench. Regarding the chemical action, five VOC are tested, two ketones: acetone and butanone, two esters: methyl-butyrate and methyl-valerate, one aldehyde: butyraldehyde. They are injected at low concentration in a continuous air flow according to two modes of injection: (i) separately at 25 ppmv, or (ii) together at 10 ppmv each one, i.e. 50 ppmv total. The air flow rate is modulated via an additional pump for investigating an extended range: 8.5-179 L/min. Thus, for a fixed 60 W consumption, the specific input energy (SIE) goes from 20 J/L to 423 J/L. As expected, the results show that as the SIE is increased, better conversion rates are achieved. Based on the experimental results, a chemical model of the SDBD reactor is proposed for providing a physical interpretation while giving information for helping the design of an optimized double-action reactor.