Presentation is loading. Please wait.

Presentation is loading. Please wait.

University of Michigan, Ann Arbor, MI, 48109, USA

Published byNoreen Morris Modified over 6 years ago

Similar presentations

Presentation on theme: "University of Michigan, Ann Arbor, MI, 48109, USA"— Presentation transcript:

1 University of Michigan, Ann Arbor, MI, 48109, USA
Effects of inter-pulse residual species on discharges in packed bed reactors* Juliusz Kruszelnicki, Kenneth W. Engeling, John E. Foster, and Mark J. Kushner University of Michigan, Ann Arbor, MI, 48109, USA MIPSE OCTOBER 2016  * Work supported by the Department of Energy Office of Fusion Energy Science and the National Science Foundation.

2 University of Michigan Institute for Plasma Science & Engr.
AGENDA Introduction to Plasma Packed Bed Reactors for Gas Reprocessing. Descriptions of the model and experiment. Description of Discharge Evolution. Gas Properties: Photoionization Gas Temperature Properties of Packing Material: Secondary Electron Emission Dielectric Constant Concluding Remarks. Application for atm discharges University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

3 University of Michigan Institute for Plasma Science & Engr.
PACKED BED REACTORS Pebbles (or beads) of high dielectric constant provides electric field enhancement. Discharge occurs between and on surfaces of beads. Plasmas in Packed Bed Reactors (PBRs) are used for: Ozone generation CO2 & CO conversion VOC (e.g., benzene, acetaldehyde, p-xylene, toluene) removal Application for atm discharges X. Tu et al., Trans. Plasma Sci. 39, 2172, (2011). University of Michigan Institute for Plasma Science & Engr. NSF_Brief_2016

4 COLLABORATION: OBJECTIVES
Experiment Modeling 2D PBR: visual inspection. Describe breakdown mechanisms. Characterize types of discharges in PBRs. Understand means of reactant production in plasmas in PBRs. Validate models with experiments. Improve operation of PBRs. Application for atm discharges University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

5 University of Michigan Institute for Plasma Science & Engr.
MODEL: nonPDPSIM Plasma Hydrodynamics Poisson’s Equation Gas Phase Plasma Bulk Electron Energy Transport Kinetic “Beam” Electron Transport Unstructured mesh. Fully implicit plasma transport. Time slicing algorithms between plasma and fluid timescales. Neutral Transport Navier-Stokes Neutral and Plasma Chemistry Radiation Transport Surface Chemistry and Charging Ion Monte Carlo Simulation University of Michigan Institute for Plasma Science & Engr. MIPSE_2016 5 5

6 DESCRIPTION OF EXPERIMENT
2-D Packed Bed Reactor Width: 0.8 cm Length: 1 cm Depth: 0.5 cm Pin-to-planar electrodes. Dielectric rods. K. Engeling et al. Application for atm discharges University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

7 University of Michigan Institute for Plasma Science & Engr.
BASE CASE CONDITIONS Mesh, geometry, and initial electric field. Reaction mechanism: N2/O2/H2O, 35 species, 143 reactions. 12,746 nodes. Photoionization of O2 by radiation from N2** Humidity: University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

8 BASE CASE – DISCHARGE EVOLUTION
Initial negative streamer enters lattice. Regions of field enhancement experience positive restrikes. Standing filamentary microdischarges (FMs) form. Surface charging destabilizes FMs. Surface ionization waves (SIWs) form. Peak electron density near dielectric surfaces. Humidity: University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

9 BASE CASE – DISCHARGE EVOLUTION
Initial negative streamer enters lattice. Three main discharges: Positive restrikes. Filamentary microdischarges (FMs). Surface ionization waves (SIWs). Humidity: Experiment Model University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

10 BASE CASE – DISCHARGE EVOLUTION
Experiment: Optical imaging of discharge formation. 5ns gate. Model: Electron density evolution. 4-decade log scale, 1×1015 cm-3 peak value. Humidity: University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

11 BASE CASE – REACTIVE SPECIES
Inventory (volume integral) of reactive species depends on transient events as discharge propagates through PBR. Positive restrikes and SIWs produces spikes in densities. Differences in species’ dependences based precursor reactions. Humidity: University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

12 REACTIVE SPECIES: DEPENDENCE ON DISCHARGE TYPE
Reactant inventories, electron density. Restrikes (I) produce more N. FMs (II), SIWs (III) produce O. Restrikes include hot electrons O2+e-(5 eV)→O+O+e- N2+e-(12 eV)→N+N+e- Type of discharge affects selectivity. University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

13 University of Michigan Institute for Plasma Science & Engr.
GAS FLOW: VELOCITY Gas velocity distribution for different SCCM flow rates. PBRs use gas flow to collect products in repetitively pulsed discharges. Stagnant regions form where flow is shielded by dielectric. Humidity: University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

14 GAS FLOW: PRE-IONIZTION
Total density of charge species at the end of 1 ms inter-pulse period. Gas flow redistributes reactants from previous pulse which affects both propagation of plasma and production of reactants. Ions, electrons and excited states flow downstream between pulses. With low gas flow, large degree of pre-ionization remains between pulses. Humidity: University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

15 GAS FLOW: DISCHARGE FORMATION
Electron density during third pulse for different SCCM flow rates. Discharge follows plume of pre-ionization and reactants (lower ionization potential) from previous pulse. High gas pressure gradients required to drive high flow rates decrease discharge propagation speed. Pre-charged gas is easier to breakdown leading to increased energy efficiency. Humidity: University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

16 GAS FLOW: REACTIVE SPECIES
Due to differences in mass, different species evacuate at different rates. Each also shot ‘sees’ different species. Both factors impact selectivity. University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

17 PULSE FREQUENCY: PREIONIZATION
Positive ions after inter-pulse periods: 1 ms, 0.1 ms, and 10 μs. The important scaling is (residence time)/(pulse period). Higher frequency (short pulse period) has a similar effective impact as low gas flow (long resident time). Humidity: University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

18 PULSE FREQUENCY: PREIONIZATION
Electron densities at the end of third pulse at different frequencies. Plumes of preionization cause breakdown in different regions – more uniform discharges seen with high frequencies. Humidity: University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

19 PRF - PRODUCTION OF REACTIVE SPECIES
Inventories of reactive species at different frequencies. At high frequency, reactive species do not flow out of plasma zone between pulses. Next pulse "sees" different set of species. Selectivity in producing reactants in part determined by number of pulses each volume element sees. 1 kHz 10 kHz University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

20 University of Michigan Institute for Plasma Science & Engr.
CONCLUDING REMARKS Pre-ionization plays a crucial role in discharge development in PBRs. Reactive species are evacuated by gas flow. At low gas flow rates, densities build up and saturate. High frequency allows for build up of charge, leading to easier breakdown. Each pulse sees different set of species. University of Michigan Institute for Plasma Science & Engr. MIPSE_2016

Download ppt "University of Michigan, Ann Arbor, MI, 48109, USA"

Similar presentations

STARTING MECHANISMS FOR HIGH PRESSURE METAL HALIDE LAMPS * Brian Lay**, Sang-Hoon Cho and Mark J. Kushner University of Illinois Department of Electrical.

STARTING MECHANISMS FOR HIGH PRESSURE METAL HALIDE LAMPS * Brian Lay**, Sang-Hoon Cho and Mark J. Kushner University of Illinois Department of Electrical.
PROPERTIES OF NONTHERMAL CAPACITIVELY COUPLED PLASMAS GENERATED IN NARROW QUARTZ TUBES FOR SYNTHESIS OF SILICON NANOPARTICLES* Sang-Heon Song a), Romain.

PROPERTIES OF NONTHERMAL CAPACITIVELY COUPLED PLASMAS GENERATED IN NARROW QUARTZ TUBES FOR SYNTHESIS OF SILICON NANOPARTICLES* Sang-Heon Song a), Romain.
ION ENERGY DISTRIBUTIONS IN INDUCTIVELY COUPLED PLASMAS HAVING A BIASED BOUNDARY ELECTRODE* Michael D. Logue and Mark J. Kushner Dept. of Electrical Engineering.

ION ENERGY DISTRIBUTIONS IN INDUCTIVELY COUPLED PLASMAS HAVING A BIASED BOUNDARY ELECTRODE* Michael D. Logue and Mark J. Kushner Dept. of Electrical Engineering.
CONTROL OF ELECTRON ENERGY DISTRIBUTIONS AND FLUX RATIOS IN PULSED CAPACITIVELY COUPLED PLASMAS* Sang-Heon Song a) and Mark J. Kushner b) a) Department.

CONTROL OF ELECTRON ENERGY DISTRIBUTIONS AND FLUX RATIOS IN PULSED CAPACITIVELY COUPLED PLASMAS* Sang-Heon Song a) and Mark J. Kushner b) a) Department.
CONTROL OF ELECTRON ENERGY DISTRIBUTIONS IN INDUCTIVELY COUPLED PLASMAS USING TANDEM SOURCES* Michael D. Logue (a), Mark J. Kushner (a), Weiye Zhu (b),

CONTROL OF ELECTRON ENERGY DISTRIBUTIONS IN INDUCTIVELY COUPLED PLASMAS USING TANDEM SOURCES* Michael D. Logue (a), Mark J. Kushner (a), Weiye Zhu (b),
MODELING OF H 2 PRODUCTION IN Ar/NH 3 MICRODISCHARGES Ramesh A. Arakoni a), Ananth N. Bhoj b), and Mark J. Kushner c) a) Dept. Aerospace Engr, University.

MODELING OF H 2 PRODUCTION IN Ar/NH 3 MICRODISCHARGES Ramesh A. Arakoni a), Ananth N. Bhoj b), and Mark J. Kushner c) a) Dept. Aerospace Engr, University.
OPTIMIZING THE PERFORMANCE OF PLASMA BASED MICROTHRUSTERS* Ramesh A. Arakoni, a) J. J. Ewing b) and Mark J. Kushner c) a) Dept. Aerospace Engineering University.

OPTIMIZING THE PERFORMANCE OF PLASMA BASED MICROTHRUSTERS* Ramesh A. Arakoni, a) J. J. Ewing b) and Mark J. Kushner c) a) Dept. Aerospace Engineering University.
MULTISCALE SIMULATION OF FUNCTIONALIZATION OF SURFACES USING ATMOSPHERIC PRESSURE DISCHARGES * Ananth N. Bhoj a) and Mark J. Kushner b) a) Department of.

MULTISCALE SIMULATION OF FUNCTIONALIZATION OF SURFACES USING ATMOSPHERIC PRESSURE DISCHARGES * Ananth N. Bhoj a) and Mark J. Kushner b) a) Department of.
NUMERICAL INVESTIGATION OF WAVE EFFECTS IN HIGH-FREQUENCY CAPACITIVELY COUPLED PLASMAS* Yang Yang and Mark J. Kushner Department of Electrical and Computer.

NUMERICAL INVESTIGATION OF WAVE EFFECTS IN HIGH-FREQUENCY CAPACITIVELY COUPLED PLASMAS* Yang Yang and Mark J. Kushner Department of Electrical and Computer.
EFFECT OF PRESSURE AND ELECTRODE SEPARATION ON PLASMA UNIFORMITY IN DUAL FREQUENCY CAPACITIVELY COUPLED PLASMA TOOLS * Yang Yang a) and Mark J. Kushner.

EFFECT OF PRESSURE AND ELECTRODE SEPARATION ON PLASMA UNIFORMITY IN DUAL FREQUENCY CAPACITIVELY COUPLED PLASMA TOOLS * Yang Yang a) and Mark J. Kushner.
SiO 2 ETCH PROPERTY CONTROL USING PULSE POWER IN CAPACITIVELY COUPLED PLASMAS* Sang-Heon Song a) and Mark J. Kushner b) a) Department of Nuclear Engineering.

SiO 2 ETCH PROPERTY CONTROL USING PULSE POWER IN CAPACITIVELY COUPLED PLASMAS* Sang-Heon Song a) and Mark J. Kushner b) a) Department of Nuclear Engineering.
ISPC 2003 June 22 - 27, 2003 Consequences of Long Term Transients in Large Area High Density Plasma Processing: A 3-Dimensional Computational Investigation*

ISPC 2003 June , 2003 Consequences of Long Term Transients in Large Area High Density Plasma Processing: A 3-Dimensional Computational Investigation*
WAVE AND ELECTROSTATIC COUPLING IN 2-FREQUENCY CAPACITIVELY COUPLED PLASMAS UTILIZING A FULL MAXWELL SOLVER* Yang Yang a) and Mark J. Kushner b) a) Department.

WAVE AND ELECTROSTATIC COUPLING IN 2-FREQUENCY CAPACITIVELY COUPLED PLASMAS UTILIZING A FULL MAXWELL SOLVER* Yang Yang a) and Mark J. Kushner b) a) Department.
FLUORINATION WITH REMOTE INDUCTIVELY COUPLED PLASMAS SUSTAINED IN Ar/F 2 AND Ar/NF 3 GAS MIXTURES* Sang-Heon Song a) and Mark J. Kushner b) a) Department.

FLUORINATION WITH REMOTE INDUCTIVELY COUPLED PLASMAS SUSTAINED IN Ar/F 2 AND Ar/NF 3 GAS MIXTURES* Sang-Heon Song a) and Mark J. Kushner b) a) Department.
SiO 2 ETCH RATE AND PROFILE CONTROL USING PULSE POWER IN CAPACITIVELY COUPLED PLASMAS* Sang-Heon Song a) and Mark J. Kushner b) a) Department of Nuclear.

SiO 2 ETCH RATE AND PROFILE CONTROL USING PULSE POWER IN CAPACITIVELY COUPLED PLASMAS* Sang-Heon Song a) and Mark J. Kushner b) a) Department of Nuclear.
THE WAFER- FOCUS RING GAP*

THE WAFER- FOCUS RING GAP*
PLASMA DISCHARGE SIMULATIONS IN WATER WITH PRE-EXISTING BUBBLES AND ELECTRIC FIELD RAREFACTION Wei Tian and Mark J. Kushner University of Michigan, Ann.

PLASMA DISCHARGE SIMULATIONS IN WATER WITH PRE-EXISTING BUBBLES AND ELECTRIC FIELD RAREFACTION Wei Tian and Mark J. Kushner University of Michigan, Ann.
WAFER EDGE EFFECTS CONSIDERING ION INERTIA IN CAPACITIVELY COUPLED DISCHARGES* Natalia Yu. Babaeva and Mark J. Kushner Iowa State University Department.

WAFER EDGE EFFECTS CONSIDERING ION INERTIA IN CAPACITIVELY COUPLED DISCHARGES* Natalia Yu. Babaeva and Mark J. Kushner Iowa State University Department.
MAGNETICALLY ENHANCED MULTIPLE FREQUENCY CAPACITIVELY COUPLED PLASMAS: DYNAMICS AND STRATEGIES Yang Yang and Mark J. Kushner Iowa State University Department.

MAGNETICALLY ENHANCED MULTIPLE FREQUENCY CAPACITIVELY COUPLED PLASMAS: DYNAMICS AND STRATEGIES Yang Yang and Mark J. Kushner Iowa State University Department.
EDGE EFFECTS IN REACTIVE ION ETCHING: THE WAFER- FOCUS RING GAP* Natalia Yu. Babaeva and Mark J. Kushner Iowa State University Department of Electrical.

EDGE EFFECTS IN REACTIVE ION ETCHING: THE WAFER- FOCUS RING GAP* Natalia Yu. Babaeva and Mark J. Kushner Iowa State University Department of Electrical.

Similar presentations

Ads by Google