| AVS 59th Annual International Symposium and Exhibition | |
| Energy Frontiers Focus Topic | Wednesday Sessions |
| Session EN+PS-WeM |
| Session: | Plasmas for Photovoltaics and Energy Applications |
| Presenter: | R. Engeln, Eindhoven University of Technology, the Netherlands |
| Authors: | S. Welzel, Eindhoven University of Technology, the Netherlands S. Ponduri, Eindhoven University of Technology, the Netherlands F. Brehmer, Eindhoven University of Technology, the Netherlands M. Ma, Eindhoven University of Technology, the Netherlands M.C.M. van de Sanden, Eindhoven University of Technology, the Netherlands R. Engeln, Eindhoven University of Technology, the Netherlands |
| Correspondent: | Click to Email |
Recently research in 'solar fuels' has been stimulated by the forthcoming depletion of fossil fuels along with a slowly increasing share of intermittently available renewable sources. New efficient methods of harvesting renewable (e.g. solar) energy and its storage in high energy density chemical fuels are therefore highly desirable. CO2 and its recycling into 'solar fuels' will be an essential element in the future transport and energy infrastructure. Plasma-processing of CO2 in the gas phase under low-temperature non-equilibrium conditions is thereby a promising alternative to specifically tackle the rate-limiting dissociation into CO. Two aspects of such a plasma-assisted CO2 treatment have been studied and are detailed in this contribution.
Firstly, the direct hydrogenation of COx in a plasma-expansion created from mixtures of Ar and H2 was investigated. Different (metallic) surface materials were employed to assess the influence of surface reactions on the molecule formation. Mass-spectrometry and infrared absorption spectroscopy were applied to quantify the gas phase composition of such argon-ion and hydrogen-radical enhanced plasmas. Although CO was a main product with up to 50 % conversion yield, the separation of CO2 dissociation and subsequent hydrogenation was strongly suggested to optimise both processes individually. Furthermore it transpired that plasma-catalysis require new surface materials that are different from conventional catalysts: a copper surface typically reduced the CO and CH4 yields by 50 %.
Secondly, to particularly account for the individual optimisation of the CO2 dissociation and scrutinise the (energy) efficiency of the conversion process dielectric barrier discharges in CO2 were studied. The focus was on establishing a consistent energy-balance of the proposed plasma-assisted route and involved the analysis of energy injected to the power supply, the transfer to the discharge and the correlation with the CO2 conversion. Through reduction of loss channels in the resonance circuit operated in the kHz-range clearly more than 50 % of the input power were directly injected to the plasma. Plasma parameters such as electron and vibrational temperatures and the population distribution of excited species were determined to further characterise the excitation and dissociation channels in the CO2 plasma.