gas and surface applications of atmospheric …...• deposition methods in n 2-atmosphere main: rf...
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Gas and surface applications of atmospheric pressure plasmas Eugen Stamate Technical University of Denmark Roskilde – 4000, Denmark
DTU Energy Conversion, Technical University of Denmark
OUTLINE
• Introduction of DTU Energy Conversion and Storage • Activities in Reactive Plasma Processing laboratory - Thin film batteries - NOx reduction - Bacterial inactivation
DTU Energy Conversion, Technical University of Denmark
Technical University of Denmark – DTU Excellence since 1829
MISSION Create value for society using
the natural and technical sciences
Total students ~8.500 including Ph.D. 1.200
and Int. M.Sc. 650
Research publications 3.600
Leiden Crown Indicator 2010: no. 1 in Scandinavia no. 7 in Europe
DTU Energy Conversion, Technical University of Denmark
DTU organization
DTU Energy Conversion, Technical University of Denmark
Department of Energy Conversion and Storage • Sustainable technologies for energy conversion and storage
• 250 people (70 scientific staff)
• Research span from fundamental investigations to component
manufacture
• Focus on industrial collaboration and industrially relevant processes
• Created 2012, bringing together outstanding research groups from – Risø DTU National Laboratory
for Sustainable Energy – DTU Chemistry
• Located on two campuses: Risø and Lyngby
DTU Energy Conversion, Technical University of Denmark
Research activities in the Department of Energy Conversion and Storage
• Solid oxide fuel cells • High-temperature polymer electrolyte fuel cells • Electrolysis • Polymer solar cells • Batteries • Synthetic fuels • Membranes for oxygen or hydrogen separation • Magnetic refrigeration • Thermoelectric components • Flue gas purification using electrochemical cells • Superconducting components
• FCH Test Center for
fuel cell and hydrogen technologies
DTU Energy Conversion, Technical University of Denmark
Case study: Solid Oxide Fuel Cells Research • Better materials
• New cell designs
• Improved manufacturing processes
• Improved durability
• Long term tests
DTU Energy Conversion, Technical University of Denmark
Polymer solar cells • Promising alternative to traditional Si-based
photovoltaics
• Organic photovoltaics printed on flexible plastic substrates
• High-speed roll-to-roll processing – very low production costs – low capital investment – high throughput
• Research focus on increased efficiency and
lifetime
DTU Energy Conversion, Technical University of Denmark
Magnetic refrigeration • Uses the magnetocaloric effect
• Ceramic materials with tunable transition temperature
• Advantages
– high efficiency – low-noise operation – environmentally friendly (no volatile gases)
• Both for refrigeration and heat pumps
• Prototype designed and constructed at DTU
– 200 W cooling power @ 18 °C span – further optimization under way
N S
N S
DTU Energy Conversion, Technical University of Denmark
Thermoelectrics • Use of the Seebeck effect to generate
electricity
• Conversion of waste heat from, e.g., solid oxide fuel cells
• Oxide materials for operation at 400-1000 °C
• Aim is to demonstrate a device with a conversion efficiency approaching 15-20%
DTU Energy Conversion, Technical University of Denmark
Reactive plasma processing
• Part of ElectroFunctional Materials (EFM) section • Established in September 2006 Main activities - Thin films for electrochemical cells (SOFC, batteries, catalytic
materials) - Plasma technologies for environment (NOx/SOx reduction) - Etching - Plasma immersion ion implantation - Plasma sources (ECR, ICP, Sputtering, DBD) and diagnostics
(probes, mass spectrometry, optical emission spectroscopy, absorption spectroscopy)
DTU Energy Conversion, Technical University of Denmark
Surface functionalization and thin films -insulating materials (charging effects) - temperature sensitive materials (polymers, plastics, bio-samples) - controllability of incident angle (process tuning) - large surface (high throughput)
Extraction of a focused ion beam using slit. [E. Stamate, US patent (2011)]
Matrix-ECR plasma source in RPP at DTU
DTU Energy Conversion, Technical University of Denmark
Li thin film batteries
Sm
all v
olum
e an
d
high
pow
er d
ensi
ty
Targeted applications: - MEMS - Smart cards - Micro-cameras - Microelectronics
Koo et al., Nanoletters (2012)
Thin-film battery
Energy storage – essential for an information based society
DTU Energy Conversion, Technical University of Denmark
Lithium Ion Batteries
All-solid thin film Lithium ion battery
Needs to be compatible with soldering – stand more than 220°C
Both electrodes are capable of reverse lithium insertion. Because of difference in chemical potential the transport delivers
(discharge) or consumes (charge) energy.
Conventional Lithium ion battery
Less compatible with micro and nanoelectronic devices, safety issues
Requirements: - High ionic conductivity - Stability with anode and cathode - Large potential window
DTU Energy Conversion, Technical University of Denmark
Material: Li3PO4 (Developed in ’90s at Oak Ridge laboratories by Bates and coworkers) • Deposited film: Lithium phosporus oxinitride (LiPON): Li3.3PO3.9N0.17 (glassy)
• Moderate conductivity, compensated with a film thickness of about 1 µm
• Deposition methods in N2-atmosphere
Main: RF magnetron sputtering (2-4 nm/min sintered, 30 nm/min powder)
Alternative: Ion beam assisted deposition, Pulsed laser deposition, E-beam
evaporation, Plasma assisted direct vapor deposition, Plasma enhanced
metalorganic CVD
Introduction - Lipon
• Moderate Li+ ion conductivity • Reacts with air
Challenges
How to increase the conductivity?
DTU Energy Conversion, Technical University of Denmark
RF & ECR setups for diagnostics
3x4 matrix of ECR distributed plasma cells – Boreal Plasma ®
DTU Energy Conversion, Technical University of Denmark
FIB-SEM 50 mTorr, 100 W, 7 h 0.59 µm
5 mTorr, 100 W, 7 h 1.43 µm
Pressure (mTorr)
Conductivity (µS/cm)
5 2.16a
20 1.58 50 0.47
20 mTorr, 100 W, 7 h 0.97 µm
Lipon 1 µm
Au 100 nm
Ag, Au 300 nm
Si wafer
DTU Energy Conversion, Technical University of Denmark
Mass appearance spectrometry
Nitrogen dissociation is significantly higher at low
pressure
Lithium availability is high at low pressure
DTU Energy Conversion, Technical University of Denmark
Ozone
High temperature
burner
NOx
NOx N2O5 O3
NOx reduction
Power plants, gas turbines incinerators, boilers,
diesel, etc.
NO+O3 → NO2+O2
2NO2+O3 → N2O5+O2
N2O5+H2O → 2HNO3
HNO3 (aid rain)
Strong negative effects on the quality of air, soil and
human health
Use the same principle to reduce the NOx under controllable conditions
DTU Energy Conversion, Technical University of Denmark
Typical NOx reduction setup
REACTOR scrubber
neutralizer
water
catalyst
flue gas blower
drain ozone
generator Power O2 flow
O2/O3 flow 1-3
4 5
6-7
8
9 10
11-13 stack
1. Flue gas flow 2. NOx concentration 3. Inlet flue gas temperature 4. Electric power to ozone generator 5. Oxygen production 6. Oxygen consumption 7. Ozone production 8. Reactor temperature 9. pH in scrubber media 10. Temperature of scrubber media 11. Ozone concentration after scrubber 12. Temperature after scrubber 13. NOx after scrubber
DTU Energy Conversion, Technical University of Denmark
• 6 m long reactor • up to 250 SLM flue gas • up to 100 g/h O3 (air, O2) • NO, NO2, O3 sensors • 7 sampling ports • Controlled gas flows • Gas and reactor heating • Wet scrubber • O3 destroyer • NOx up to 10000 ppm • PC control
NOX/SOx PlasTEP reactor built at DTU
DTU Energy Conversion, Technical University of Denmark
NOx/SOx PlasTEP reactor built at DTU
DTU Energy Conversion, Technical University of Denmark
NOx/SOx PlasTEP reactor at DTU
DTU Energy Conversion, Technical University of Denmark
NOx/SOx PlasTEP reactor built at DTU
DTU Energy Conversion, Technical University of Denmark
NO2 and O3R as a function of O3
IN at P1 for all four mixing schemes for an air flow of 40 slm, ozonized air of 10 slm, 0.027 slm of NO and initial values of
NO=316 ppm and NO2=104 ppm (O3IN=0 ppm).
Mixing schemes
DTU Energy Conversion, Technical University of Denmark
Constant O3IN, “on-off” NO, NOx at P1 and P5 for 50 slm dry air, 0,21 slm NO,
NOx_on= 411 ppm, NO_on= 304 ppm. O3IN=1900 ppm, Power ozone generator =
256 W.
Time dependence
DTU Energy Conversion, Technical University of Denmark
Bacterial Inactivation using DBD plasma Te
mp
erat
ure
Time
- Initial bacterial concentration - Growth rates in specific packages
- What is the life time of a food product ? - Can we extend it ?
Time
DTU Energy Conversion, Technical University of Denmark
Effect of MAP with CO2 on seafood products
Packaging Shelf-life (days at 0°C)
TMA at sensory rejection
(mg-N/100g)
Drip loss at sensory
rejection (%) Vacuum 12 - 14 ~30 4.7 30% CO2 14 - 16 ~30 6.2 50% CO2 16 – 20 ~30 7.9
Modified atmosphere packaging (MAP) with CO2 is successfully used for fresh and slightly coked see food products
for more than 15 years
DTU Energy Conversion, Technical University of Denmark
Water cooled electrodes
HV electrode
Gap spacer (3-10 mm)
Experimental setup
Copper thin film deposed on dielectric
substrates (avoid heating of dielectrics
by parasite discharge)
• Electrodes surface: 50x50 mm2 • Total surface of the package: 80x80 mm2 • Maximum thickness: 10 mm.
DTU Energy Conversion, Technical University of Denmark
Details - closed container
Quartz window
DTU Energy Conversion, Technical University of Denmark
Plasma effect on sensory properties of salmon
• Sensory properties: color, texture • Samples: sliced cold-smoked salmon packed in plastic bags • Treatment variables: applied voltage (Vpp), frequency, gas gap, treatment time.
Applied voltage
(kV)
Frequency (kHz)
Gas gap
(mm)
Treatment time
(min.)
Sensory properties (appearance,
texture )
13 14 10 1 Acceptable
13 14 10 2 Acceptable
13 18 10 1 Acceptable
13 18 10 2 Acceptable
13 20 10 1 Acceptable
15 14 10 1 Acceptable
15 14 10 2 NOT acceptable
18 14 10 1 NOT acceptable
20 14 10 1 NOT acceptable
7 16 5 3 Acceptable
7 16 5 5 Acceptable
DTU Energy Conversion, Technical University of Denmark
Preliminary tests on ceramic plates for atmospheric discharges
DTU Energy Conversion, Technical University of Denmark
Preliminary tests