Limitations of NOx removal by pulsed corona reactors

No abstract

Application of a compact 2 kW pulsed corona unit

Only abstrac

Toepassingen van D/I meetsystemen

IN POWER GRIDS VOLTAGES AND CURRENTS SHOULD BE RELIABLY MEASURED DURING OVERVOLTAGES, SWITCHING EVENTS AND FAULT SITUATIONS BUT ALSO DURING 50 Hz OPERATION. THE MEASURING SYSTEM WHICH LINKS THE POWER SYSTEM, FOR INSTANCE A SUBSTATION, TO THE DATA HANDLING, SHOULD CORRECTLY ADAPT THE SIGNALS TO THE MODERN ELECTRONICS. OTHER SPECIFICATIONS ARE THE SYSTEM’S EMC QUALITY, ITS BANDWIDTH, LINEARITY AND COST AND ITS APPLICABILITY IN OPEN AND CLOSED SUBSTATIONS. A COMPLETE SYSTEM IS DESCRIBED THAT EXCELLENTLY FITS ABOVE REQUIREMENTS. THE APPLIED DIFFERENTIATING/INTEGRATING PRINCIPLE IS SIMPLE, HAS A LARGE BANDWIDTH AND HIGH EMC QUALITY, AND CAN BE USED WITH LONG COAXIAL CABLES. GLASS FIBERS ARE NOT NEEDED. WE APPLY THE SYSTEM IN OUR HIGH-VOLTAGE WORK, FOR SUBSTATION MEASUREMENTS AND IN MANY THIRD PARTY EMC PROJECTS, OFTEN WITH RESPECT TO LIGHTNING PROTECTIO

Pulsed power corona discharges for air pollution control

Successful introduction of pulsed corona for industrial purposes very much depends on the reliability of high-voltage and pulsed power technology and on the efficiency of energy transfer. In addition, it is of the utmost importance that adequate electromagnetic compatibility (EMC) is achieved between the high-voltage pulse source and the surrounding equipment. Pulsed corona is generated in a pilot unit that produces narrow 50 MW pulses at 1000 pps (net average corona power 1.5 kW). The pilot unit can run continuously for use in industrial applications such as cleaning of gases (100 m3/h) containing NO or volatile organic compounds (VOCs) or fluids (e.g., waste water). Simultaneous removal of NO and ethylene to obtain clean CO2 from the exhaust of a combustion engine was tested at an industrial site. Various chemical processes, such as removal of toluene or styrene from an airflow are tested in the laboratory. We developed a model to analyze the conversion of these pollutants. To examine the discharges in the reactor we use current, voltage, and E-field sensors as well as a fast charge-coupled device (CCD) camera. Detailed energy input measurements are compared with CCD movies to investigate the efficiency of different streamer phases. EMC techniques incorporated in the pilot unit are based on the successful concept of constructing a low transfer impedance between common mode currents induced by pulsed power and differential mode voltages in signal lines and external main line

Matching a nanosecond pulse generator to a corona plasma reactor

abstract onl

Temperature-programmed plasma surface reaction:An approach to determine plasma-catalytic performance

\u3cp\u3ePlasma-enhanced heterogeneous catalysis offers a promising alternative to thermal catalysis due to the synergy between the plasma and the solid catalyst. However, there is only a limited mechanistic insight about the interactions of highly energetic electrons and excited molecules with heterogeneous catalysts in plasmas. Accurate performance comparison in a plasma-catalytic setting is complicated because of the intricate nature of the plasma-catalyst system: simultaneous reactions occurring in the gas-phase and at the catalytic surface; the dependence of the discharge on dielectric properties of the packed catalyst bed; and the dependence of permittivity and polarization of the catalyst on plasma parameters. Here, we present a method of temperature-programmed plasma surface reaction (TPPSR) that allows decoupling gas-phase processes from the surface plasma-induced reactions. Using this method we reveal the main reasons of apparent synergy between plasma and heterogeneous catalyst for the case of carbon dioxide hydrogenation. Experiments with isotopically labelled CO\u3csub\u3e2\u3c/sub\u3e and temperature-programmed plasma reaction experiments in flow of CO\u3csub\u3e2\u3c/sub\u3e/H\u3csub\u3e2\u3c/sub\u3e prove a substantial role of gas-phase dissociation/hydrogenation for the observed catalyst activity and selectivity. The product distribution and reaction pathways do not significantly depend on the discharge parameters. Taking into account overheating of the catalytic bed for comparison of catalytic activity with and without plasma, it was concluded that energy dissipation also plays an important role. The observed plasma enhancement is in part due to the acceleration of electron-induced surface reactions.\u3c/p\u3