/e

Introduction

Aside from being challenging fundamental physical phenom-ena to study, plasmas exhibit properties that make them use-ful in industrial applications.

• The main objective of this project is to quantify and tooptimize the chemical activity of pulsed atmosphericstreamer plasmas with the purpose of air purification.

Polluted Air Plasma Clean Air

Figure 1: Corona plasma for air purification.

By changing the pulsed power generator settings, differentregimes and properties of the streamer plasma can be mod-ified, studied and optimized (Fig. 2).

Pulse source Streamers Reactivespecies

Chemicalreactions

Process

OO(1D)

O−O

+2

OHN...

OH + N → H + NOO2 + N → O + NON + NO → N2 + ON + NO2 → 2NO

...

E∆ttriseT

eV

#

J/..

[ ]P[ ]ε

Electron energy tuningImpedence matching

Figure 2: Corona plasma: from generation to process.

Expected Results

• A thorough analysis of pulsed power generator settingsand regimes for different plasma processes.

• Methods to tune pulse power settings for optimalplasma performance.

Nanosecond Pulse Generation

• Goal: generate an order of magnitude shorter pulses(<5 ns) pulses than previously achieved.

• <5 ns, high E-field pulses will boost the yield of radicalsgenerated by the plasma (Fig. 3,4 [1]).

• A Blumlein concept will be adapted for this purpose.

40 60 80 100Voltage [kV]

0

2

4

6

8

30 ns FWHM50 ns FWHM

100 ns FWHM130 ns FWHM

O* pr

oduc

tion

[mol

e kW

h-1 ]

Figure 3: Shorter pulses result in moreradicals.

0

2

4

6

8

10

12

0 0.5 1.0 1.5 2.0 2.5Velocity [106 m s-1]

Primary CDSSecondary CDSPrimary ADSSecondary ADS

O* ra

dical

yie

ld [m

ole

kWh-

1 ]

Figure 4: Preventing secondary stream-ers results in more radicals.

Experimental Setup

VoltageCurrentEnergy

SpectroscopyGas diagnosticsICCD camera

Electricity grid High-voltage charger ns-Pulse generator Plasma reactor

Figure 5: The experimental setup with diagnostics.

Impedance Matching

• Goal: very high energy transfer from pulsed power gen-erator to the plasma.

• Problem: plasma is a highly transient, voltage depen-dent (Fig. 6, 7) and non-linear load.

• In this project new ways of matching a pulse generatorto a corona plasma will be investigated

Figure 6: Plasma impedance decrease.

0

1

2

3

50 65 80 95Voltage [kV]

Load / Source impedance ratio

wire-cylinder 3/160 mm

wire-cylinder 1/250 mm

Figure 7: Voltage controlled matching.

Model processes

Several model processes will be selected with the aim to iden-tify key radicals which are involved in these processes. Pulsedpower settings will be optimized towards radical generation.Examples of such model processes are ozone generation andCO2 reforming.Radicals will be measured (Fig. 8):

• Directly• From concentrations, through a kinetic model

Reactivespecies

Chemicalreactions

Process

Measure

Streamers

ConcentrationKinetic model

Figure 8: The experimental setup with diagnostics.

References

[1] H. Winands, “Efficient streamer plasma generation.” Eind-hoven University of Technology PhD thesis, 2007.

Pulsed Corona Plasma for Air PurificationT. Huiskamp1, A.J.M. Pemen1, E.J.M. van Heesch11 Eindhoven University of Technology