| AVS 61st International Symposium & Exhibition | |
| Energy Frontiers Focus Topic | Tuesday Sessions |
| Session EN-TuP |
| Session: | Energy Frontiers Poster Session |
| Presenter: | Waldo Bongers, Dutch Institute for Fundamental Energy Research, The Netherlands |
| Authors: | W.A. Bongers, Dutch Institute for Fundamental Energy Research, The Netherlands A.P.H. Goede, Dutch Institute for Fundamental Energy Research, The Netherlands M.F. Graswinckel, Dutch Institute for Fundamental Energy Research, The Netherlands S. Welzel, Dutch Institute for Fundamental Energy Research, The Netherlands M. Leins, Universität Stuttgart, Germany J. Kopecki, Universität Stuttgart, Germany A. Schulz, Universität Stuttgart, Germany M. Walker, Universität Stuttgart, Germany M.C.M. van de Sanden, Dutch Institute for Fundamental Energy Research, The Netherlands |
| Correspondent: | Click to Email |
In the framework of an emerging Solar Fuel program the first and essential CO2 dissociation step of CO2 into CO and O2 has been studied. The focus was thereby on high energy efficiency of the process using non-thermal (non-equilibrium) microwave plasmas without the use of rare materials. The plasma was generated by tangentially injecting CO2 gas in a quartz tube placed inside a low loss 915 MHz TM010 circular waveguide mode cavity. Powers were used up to 10 kW. The feed gas expanded supersonically after the cavity to quench the plasma and prevent vibrational-translational relaxation losses. These experiments resulted in power efficient conversion (more then 50%) of large CO2 flows (up to 75 standard liter per minute) with 11% conversion yield. The product formation was measured downstream the plasma at the expansion in a calibrated mass spectrometer.
The research at the plasma Solar Fuels facilities of DIFFER concentrates on optimization of power efficient selective vibrational CO dissociation. This can be achieved by means of several novel methods: like tuning the optimal kinetic energy range of the electrons by controlling the reduced electric field in the microwave cavity or make use of the relaxation time difference of translational and vibrational modes of CO controlled by modulating the microwave field. First results were obtained with a 2.45 GHz 1kW microwave plasma source. The source consists of a quartz tube with a tangential gas injection system placed inside a circular TEM mode coaxial cavity coupled to a TE10 rectangular waveguide mode cavity. The configuration of the coaxial cavity allows control of the electric field. With an input of 7 standard liter per minute of CO2 energy efficiencies 15% to 36% were obtained (based on CO2 depletion) in the pressure range from 1Bar (atmospheric) till 0.2 Bar. An update on these new research developments will be shown.