Catalytically Supported Oxidation of Volatile Organic Compounds (VOCs) in Non-Thermal Plasma

The emission of VOC in exhaust air streams in a low concentration range (below 1 g/m3) originated by paint shops, livestock breeding or food and chemical industry plants is a widespread environmental problem. Established thermal and thermo-catalytical cleaning processes are no longer efficient at these low VOC concentrations. Cold oxidation of VOC by non-thermal plasma (NTP) represents an alternative approach for decontaminating highly diluted VOC streams. A strong electric field (10-30 kV) causes ionization of the air stream and the formation of radicals and ions. These highly reactive species can lead to partial or total oxidation of the VOC.

Nearly all of the electrical energy is transferred only onto the charged particles, mainly electrons (T~ 10.000 K), whereas the neutral gas molecules remain almost cold (ambient temperature). However, oxidation of VOC in a homogeneous gas phase plasma is non-selective and can hardly be controlled. Therefore our research is focused on the improvement of energy efficiency and the increase in selectivity of the oxidation to carbon dioxide and water by placing solid materials in the discharge zone. Ferroelectric materials enable discharges to produce high energy electrons and therefore the formation of more reactive species. However, the main objective is based on a more effective utilization of the available reactive species (short-lived reactive oxygen species) by the application of catalyst beds in the discharge zone. 
 

 

Selected publications

U. Roland, F. Holzer, F.-D. Kopinke, Improved oxidation of air pollutants in a non-thermal plasma, CATALYSIS TODAY, 73(2002), 315-323

U. Roland, F. Holzer, F.-D. Kopinke, Combination of non-thermal plasma and heterogeneous catalysis for oxidation of volatile organic compounds Part 1. Accessibility of the intra-particle volume, APPLIED CATALYSIS B-ENVIRONMENTAL, 38 (2002), 163-181

U. Roland, F. Holzer, F.-D. Kopinke, Combination of non-thermal plasma and heterogeneous catalysis for oxidation of volatile organic compounds Part 2. Ozone decomposition and deactivation of gamma-Al2O3, APPLIED CATALYSIS B-ENVIRONMENTAL, 58 (2005), 217-226