HYBRID EVENT: You can participate in person at Paris, France or Virtually from your home or work.

4th Edition of

Chemistry World Conference

June 17-19, 2024 | Paris, France

Chemistry 2023

Stefan Nettesheim

Speaker at Chemistry World Conference 2023 - Stefan Nettesheim
Relyon plasma GmbH a TDK group company, Germany
Title : Mediplas: More than a simple ozone generator


Dielectric barrier discharge flow reactors are among the most efficient technologies to produce ozone based on oxygen. If ambient air is used the chemistry gets much more complex and involves many competing reaction pathways and yields a mixture of ozone with nitric oxide components, nitric acids, and peroxides. The process parameters that determine to a certain degree the composition of the output are: Inlet gas composition and humidity, power density of the dielectric barrier discharge, amplitude of the electric excitation, and process temperature. We have designed a reactor for typical flowrates of 0-10 slm with integrated active Peltier cooling that offers a high control over process temperature. The specially adapted driving circuit can adjust power density (via PWM) and amplitude of the excitation voltage. The driver also includes a feedback signal that is proportional to the discharge intensity. A well-defined output including very high ozoe concentrations of more than 30.000 ppm can be achieved with very high stability. However, for some sterilization and medical applications we were able to show that the sweet spot for killing germs is not necessarily the operating point of highest ozone concentration, but that the nitrogen oxide species in combination with humidity and peroxides play a decisive role. The components described in this contribution are easy to integrate into a wide range of systems and can be specifically controlled to optimize the desired effects.

Audience Takeaway:

  • Basic and practical properties of an ozone generator using a dielectric barrier discharge will 
  • be discussed.
  • The design of a specific small-scale high-performance ozone generator will be described.
  • Practical application examples including microbiological efficiency will be highlighted.
  • The research includes interdisciplinary topics of electronics, physics, chemistry, and 
  • microbiology.
  • The presented system can tune the output chemical composition using a given input gas 
  • composition e.g., humid air.
  • The described components are easy to integrate into different applications such as 
  • disinfection processes.


Dr. Stefan Nettesheim studied physics at the TU Berlin and the University of Konstanz. He received his PhDin 1993 from the Fritz Haber Institute of the Max Planck Society in Berlin. Until 1998, he worked as a postdoc at the Universidad del Pais Vasco in San Sebastian and at the Swiss Federal Institute of Technology 
Zurich (ETHZ). He then worked as a development engineer at SIG Pack Systems in Beringen, Switzerland and as division manager at Sachsenring AG in Zwickau, Germany. From 2002, he was founder and general manager of Ekpro GmbH for fuel cells in Berlin. Currently, Dr. Nettesheim is managing director of relyon plasma GmbH, a TDK Group company