Plasma-Based Pollutant Degradation in Gas Streams: Status, Examples and Outlook

The status of the research into and the application of non-thermal plasmas for the pollutant degradation in gases is discussed, including some fundamental topics and engineering issues. Two reactor concepts, both based on dielectric barrier discharges (DBDs), are presented and investigated for various tasks. The DBD-stack reactor shows a very good scalability and was investigated for the oxidation of NO in combustion gases (shipping diesel engine exhausts). The oxidation processes were significantly enhanced by the admixture of hydrocarbons. Significant NO conversion at low specific energy densities below 100 J/L were achieved in laboratory and test bench studies. The water falling film reactor demonstrated its feasibility for the removal of hydrocarbon pollutants from gases. Undecane, a long-chain, harmful hydrocarbon, was decomposed. The conversion of non-soluble compounds into soluble ones (formic acid) is a promising development towards a compact plasma-assisted scrubbing technology. These approaches are good progress not only in the field of environmental plasma application, but also for indoor air quality, hygiene, and plasma synthesis. ((c) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)