Gas and surface applications of atmospheric …...• Deposition methods in N 2-atmosphere Main: RF...

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


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 organization


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


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


Case study: Solid Oxide Fuel Cells Research • Better materials

• New cell designs

• Improved manufacturing processes

• Improved durability

• Long term tests


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

Presenter

Presentation Notes

Research targets: 10 % conversion efficiency and >10 years lifetime


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

Presenter

Presentation Notes

Magnetocaloric effect: A reversible effect in which a material heats up when a magnetic field is applied and cools down again when the field is removed. The device uses a water based heat transfer fluid.


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%


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)


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


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


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


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?


RF & ECR setups for diagnostics

3x4 matrix of ECR distributed plasma cells – Boreal Plasma ®


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


Mass appearance spectrometry

Nitrogen dissociation is significantly higher at low

pressure

Lithium availability is high at low pressure


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


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


• 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


NOx/SOx PlasTEP reactor built at DTU


NOx/SOx PlasTEP reactor at DTU


NOx/SOx PlasTEP reactor built at DTU


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


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


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


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

Presenter

Presentation Notes

During the last 15 years several fresh and lightly preserved seafood in modified atmosphere packaging have been introduced on the Danish market I am going to talk about shelf-life, quality, and safety of these products


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.


Details - closed container

Quartz window


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






15 14 10 2 NOT acceptable



7 16 5 3 Acceptable

7 16 5 5 Acceptable


Preliminary tests on ceramic plates for atmospheric discharges


Preliminary tests

Gas and surface applications of atmospheric …...• Deposition methods in N 2-atmosphere Main: RF...

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