Technological Applications of (Atmospheric … › ~bonitz › si14 › download › slides › ...Technological Applications of (Atmospheric -Pressure) (Micro)Plasmas: Opportunities

Kurt H. Becker, PhD Vice Dean for Academic Affairs

Summer School on Complex Plasmas

Seton Hall University, 2014

Technological Applications of (Atmospheric-Pressure) (Micro)Plasmas: Opportunities & Challenges

Kurt H. Becker NYU, Polytechnic School of Engineering

Science breakthrough

Engineering realization

Bench-scale prototype

Technology realization

Technology verification, proof-of concept

Customer validation

Scale-up, economics

Large-scale industrial testing

Commercialization, industry acceptance

Technology improvements




FROM: B.M. Penetrante and S.E. Schultheiss “Non-thermal Plasma Technologies for Pollution Control” Proc. NATO-ASI, Vol. 34, Plenum Press, New York (1993)

“Non-thermal plasmas have an enormous potential of becoming the leading technology for the remediation of environmental pollutants in the near future”

20 Years Later: Much of the “enormous potential” remains unrealized - why ???

What are the challenges, where are the opportunities ???

TO DATE: Only two fully commercialized large-scale plasma-based technologies in

the environmental field: Electrostatic Precipitators & Ozonizers

Not covered: • Plasma Medicine (too early, regulated)

• Plasma Light Sources (quite mature)

http://en.wikipedia.org/wiki/File:Gluehlampe_01_KMJ.png




I. Electrostatic Precipitators (using corona discharge plasmas): Removal of particulates from gas streams

• mature technology • large industrial scale • economical & efficient • reliable • little unknown science • some engineering issues




Electrostatic Precipitators (using corona discharge plasmas)






Customer validation

Scale-up, economics







II. Ozonizers (using dielectric barrier discharge, DBD, plasmas): Generation of ozone (O3) for disinfection applications

• mature technology • large industrial scale • fairly economical • fairly reliable • not efficient (< 20% O3) • some unknown science • engineering issues




Filamentary DBD and O3 Generation (complex interplay between plasma chemistry & discharge physics)

• low power, many weak filaments • low O3 generation efficiency at low O3 background concentrations • high O3 generation efficiency at high O3 background concentration

• high power, few strong filaments • low O3 generation efficiency at high O3 background concentrations • high O3 generation efficiency at low O3 background concentration




Ozone Generation in DBDs

State of the Art: • Larger ozonizers can produce up to 100 kg of O3 per hour • O3 concentrations are typically 18 wt% in O2 and 6 wt% in air • Use of O2 requires <50 ppm HC contamination • Energy for 1 kg of O3 is 8 kWh for O2 and up to 20 kWh for air • Cost is about $2 per kg of O3

Future Prospects: • Novel concepts (e.g. the IGS) can push max. O3 concentration to >20% • Advances in power semiconductors (improved gate turn-off thyristors and insulated gate bipolar transistors which can switch 1 kA at 5 kV) will reduce size of ozonizers by eliminating the need for step-up transformers and allow use of more efficient excitation waveforms • Use of homogeneous self-sustained volume discharges may lead to more favorable plasma conditions for O3 generation









Customer validation

Scale-up, economics




Ozonizers (using dielectric barrier discharge, DBD, plasmas):




Application of Low-T Plasmas in ‘High Potential’ Area: Removal of VOCs, SOx, and NOx from Gaseous Streams

Low-T plasmas have been used in bench-scale applications to: • convert VOCs in gaseous waste streams • convert SOx and NOx in gaseous waste streams • use in high-flow and low-volume applications • convert contaminants in Diesel exhaust • prepare feed gas for fuel cell

Possible show-stoppers preventing industrial-scale applications : • by-product formation (characterization, control) • carbon closure (accounting for fate of all C atoms) • competing technologies (advanced oxidation techniques, catalysts, …) • energy efficiency • economics (cost of manufacture, cost of operation, …)




Capillary Plasma Electrode (CPE) Concept

dielectric (pulsed ) dc, ac, or rf voltage

metal

metal dielectric

Capillary Plasma Electrode (CPE) Realizations

Cylindrical Electrodes

(Longitudinal Flow)

Solid Pin Electrodes

(Cross Flow) Hollow Pin Electrodes

(Flow-Through)

Some Low-T Plasma Concepts




`

AC

PC LabView

Oscilloscope

Plasma Reactor

Plasma Treatment System

FT-IR

FID

[ VOCs, NOx, COx, and O3 ]

[VOCs]

Chemicals Analysis System

Exha

ust

Carbon Trap

Mass Spectrometer

GC

Mass Spectrometer

GCCS2

Solvent Extraction

[VOCs]

/UV/Vis

(a) Off-line Analysis

(b) On-line Analysis

Gas Preparation

VOCs in dry air 50 – 1500 ppm(v)

Plasma Reactor

I-V, Power Measurement

influent effluent

Off-Line Analysis Carbon Trap

Solvent Extraction GC-MS

On-Line Analysis FTIR Absorption

GC-FID GC-MS (gas phase)

F

Flowmeter 1

F

Flowmeter 2

Impinger

VOCs Vapor

Dilution Gas

Mixtures

Com

pre

ssed A

ir

Seeded Gas Preparation System

Experimental Setup




0

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0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 Specific Energy, J/cm3

Efflu

ent C

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ppm

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Rem

oval

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Removal of n-Heptane in an Annular Plasma Reactor

(residence time: 0.6 s; initial

concentration: 700 ppm)

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0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Specific Energy, J/cm3

Efflu

ent C

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Rem

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Removal of Toluene in an Annular Plasma Reactor

(residence time: 0.6 s; initial

concentration: 490 ppm)

Two Examples




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Destr

uctio

n Effi

cienc

y (%)

Energy Density (J/cm3)

Initial contaminant concentration: 200 - 1200 ppm(v) flow rate: 2 - 8 l/min residence for maximum destruction efficiency

Benzene Destruction

A-CPE Reactor

CF-CPE Reactor

In many cases conditions can be found that will achieve essentially 100% destruction. In some cases, however, NOT (toluene !); back-reactions will limit the maximum achievable destruction efficiency.

We also developed a simple kinetic model for the species destruction and simulated the chemical conversion and did some by-product characterization.




Low-T plasmas for Environmental Applications: • High Percentage of VOC Destruction in Low-Flow Applications • Reasonable Destruction Efficiency in High-Flow Applications • Extensive Characterization of By-Products • High Level of Carbon Closure But: Challenges Remain

Scale-up to high gas flow is non-trivial Cost and energy efficiency (vs. competing technologies) Materials for long-term, maintenance-free operation Control of by-product formation Poorly understood plasma chemistry Coupling of discharge physics to plasma chemistry

SUMMARY: Low-T plasmas can be used effectively for the treatment of gaseous waste streams containing VOCs in a bench-scale R&D environment

Large-scale industrial utilization is still elusive; the technology readiness level is “stuck” at the “proof-of-concept” stage !









Customer validation

Scale-up, economics



Removal of VOCs, SOx, and NOx from Gaseous Streams

Stuck !




Solid Oxide Fuel Cell Chemistry

Low-T Plasmas for Fuel Cell Systems

300 kW Fuel Cell

2 m

Idea: Use low-T plasma to generate hydrocarbon feed gas for cell




Clean Fuel Cell Feed

Diesel Vaporization

Plasma Reactor Diesel CH4,H2, HCs

R-S + H2 H2S + R

ZnO Cartridge ZnO + H2S ZnS + H2O

Water/Steam

Conventional SOFC Process

Diesel Sulfur Removal

Pre- Reforming

Carbonate DFC/SOFC

Heat/Water Recovery

Steam Generation air steam

Exhaust

Power Conditioning

AC Power Two Catalytic Reactors

Low-T Plasma Alternative

H2

Research and Technology Initiatives




Various DBDs

High Voltage (~10-15 KHz)

Ground Wires

Dielectric

Plasma

Gas in Gas out 10”

2. Parallel-Plate DBD (PP-DBD)

Top electrode removed

1. Surface DBDs (S-DBDs) using Microrods




(1) Low & High Sulfur Fuel @ Steam/Fuel = 3

16 14 Higher Hydrocarbons 2/0 1/0 Ethane/Propane 2 5 Acetylene

29 30 Ethene 23 23 Hydrogen 28 27 % (v/v) Methane

High Sulfur Low Sulfur

(2) Effect of Steam/Fuel Ratio for NATO 76 Diesel

14 1/0 5

30 23 27

MEDIUM (3:1)

16 19 Higher Hydrocarbons 1/0 2/1 Ethene/Propane 4 4 Acetylene

33 28 Ethene 21 21 Hydrogen 25 25 % (v/v) Methane

HIGH (8:1) LOW (2:1)

Work was discontinued; technology verification / proof-of-concept stage unsatisfactory + customer validation showed significant market resistance









Customer validation

Scale-up, economics



Abandoned !

Low-T Plasmas for Fuel Cell Systems

Excimer Emission in Pure Rare Gases

The 2nd Excimer Continua are the Characteristic Emissions: Xe: 170-172 nm; Kr: 144-147 nm; Ar: 126-131 nm – all 3 are fairly narrow Ne: 76-88 nm; He: 60-90 nm – both broader and below LiF cut-off

Rare Gas Excimer Spectra are continua, the so-called 1st & 2nd Continua

Ne (400 Torr)

0

50

100

150

Wavelength (nm) 70 75 80 85 90 95

Dielectric, 250 µm

Mo Electrodes, 100 µm

-Vo, DC or pulsed

RBallast, 50 kΩ

Rcurrent viewing, 1 kΩ

Hollow Cathode, 150µm




Excimer Formation in Pure Rare Gases (a combination of electron-driven and 3-body processes)

1. Ionization Route (R = He, Ne, Ar, Kr, Xe) e- + R R+ + 2 e- (electron-driven) R+ + 2 R → R2

+ + R (3-body) R2

+ + e- R* + R (electron-driven) R* + 2 R R2

* + R (3-body) hν (excimer) + 3 R 2. Excitation Route e- + R R* + e- (electron-driven) R* + 2 R R2

* + R (3-body) hν (excimer) + 3 R What is needed: • Minimum Electron Energies of 20 – 24 eV in He, 10 – 12 eV in Xe • High Gas Density to Promote 3-Body Collisions


A High-Pressure Plasma is an Ideal Environment for Excimer Formation

Summer School on Complex Plasmas Seton Hall University, 2014

Ne2* Excimer Emission from a MHCD


Pure Ne (400 Torr)

0

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150

Wavelength (nm) 70 75 80 85 90 95

Gas purity is critical !

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Wavelength (nm)70 9080

Ne + trace of H2

Trace contamination by H2 causes the excimer continua to “disappear”


Emissions from a MHCD in a Ne-H2 (0.02%) Mixture


Rel

ativ

e In

tens

ity

Wavelength (nm) 100 150 200 250

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600

H Lyman -α

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Wavelength (nm)120100 110908070

H Lyman-α

H Lyman-β Ne2* Excimer

Emission Spectrum is dominated by H emissions, in particular by H Lyman-α

Origin of Lyman-α: (Near-Resonant) Energy Transfer from Ne2

* to H2

Ne2* + H2 → 2 Ne + H(1s) + H*(2p)

H*(2p) → H(1s) + hν (121.6 nm, Lyman-α)

Energetics: H2→ H + H E ≥ 4.48 eV H(1s) → H*(2p) E = 10.20 eV Total: E ≥ 14.68 eV

(hν) of the Ne2* 2nd Continuum:

16.3 eV (76 nm) – 14.1 eV (88 nm) most Ne2* photons have enough energy to

produce H Lyman-α via the above process


Attempt to develop a commercializable product


We built and tested (and patented) a prototype of a compact near-monochromatic H Lyman-α light source (for VUV photolithography applications)

Patterns Printed with 121-nm Source with Near Field Phase Shifter Mask

(97 nm Feature Size)

•Resist: HSQ, ≈25 nm thick

Courtesy of MIT Lincoln Lab

BUT: When our light source was ready, the industry had moved to shorter wavelengths (35 nm); there was no further commercial interest in a 121 nm source.

We had fun with the science and really got to understand the AMO physics behind it; many nice papers (incl. N2, O2, etc. contaminants)


but no success with the commercialization, product failed at the “customer validation” stage, no way to “recover” !









Customer validation

Scale-up, economics



Failed

Plasma VUV Lightsource for Photolithography




H2 Generation for Small Fuel Cells for Portable Devices

from H. Qiu et al, Int. J. Mass Spectrom. 233, 37 (2004)

0 20 40 60 80 100 120 1400

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60Plasma offPlasma on

N2

H2

NH3

Parti

al Pr

essu

re (T

orr)

Time (min)

Pass a hydro-fuel (NH3, CH4, etc.) through a microplasma reactor and generate H2 for use in small-scale fuel cells to power portable devices.

A few other examples of “promising” plasma technologies

Technology realization failed - abandoned !









Customer validation

Scale-up, economics



Failed

H2 Generation for small fuel cells for portable devices









Customer validation

Scale-up, economics



Failed

H2 Generation for small fuel cells for portable devices




Plasma Treatment of Diesel Exhaust

ENGINE

AIR FUEL

EXHAUST

PLASMA REACTOR

Pass the exhaust emission stream from a Diesel engine through a plasma reactor to convert hydrocarbon, NOx, etc. – as an alternative to a catalytic reactor

Hydrocarbon Reduction in Diesel Exhaust

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Engine power (hp)

Exha

ust T

OC

s (p

pmv)

Plasma OFF

Plasma ON

67% Reduction





Potable water harvesting from Diesel exhaust

ENGINE

AIR FUEL

CONDENSER

WATER POLISHING

STORAGE

EXHAUST

PLASMA REACTOR

Engine Power (hp)

Hydrocarbon Reduction in Harvested Water

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er T

OC

s (p

pmc)

Plasma OFF

Plasma ON

51% Reduction

Pass a fraction of the Diesel exhaust stream through a plasma reactor to convert hydrocarbons to water and reduce residual contamination.










Customer validation

Scale-up, economics



Failed

Plasma treatment of Diesel exhaust / potable water harvesting

US Patent 5,872,426 ; E. Kunhardt & K. Becker, February 16, 1999 “Glow plasma discharge device with electrode covered with perforated dielectric” Abstract A method and apparatus for stabilizing glow plasma discharges by suppressing the transition from glow-to-arc includes a perforated dielectric plate having an upper surface and a lower surface and a plurality of holes extending therethrough. The perforated dielectric plate is positioned over the cathode. Each of the holes acts as a separate active current limiting micro-channel that prevents the overall current density from increasing above the threshold for the glow-to-arc transition. This allows for a stable glow discharge to be maintained for a wide range of operating pressures (up to atmospheric pressures) and in a wide range of electric fields include DC and RF fields of varying strength. Inventors: Kunhardt; Erich E. (Hoboken, NJ), Becker; Kurt H. (New York, NY) Assignee: Stevens Institute of Technology (Hoboken, NJ) Appl. No.: 08/820,013 ; Filed: March 18, 1997 + 6 follow-on patents + application patents filed through start-ups


The “PlasmaSol Story”


The “PlasmaSol Story” The Plunge: In 1999, four graduate students from Stevens co-founded PlasmaSol to commercialize the non-thermal plasma technology: Kurt Kovach, Seth A. Tropper, Richard Crowe, and Jack Levitt + several faculty inventors. Frank Shinneman joined the company several years later as CEO.

The Approach:

• Leverage government R&D contracts toward commercialization • Collaboration / strategic partnerships

The Business Model: Stevens Institute of Technology, the owner of the IP, provided a royalty-free, exclusive, and restricted (to environmental applications and medical sterilization) license to PlasmaSol in exchange for a dilutable equity position in the company and adequate representation on the company’s Board.




The “PlasmaSol Story” PlasmaSol

Develops Products & Hires Employees




The “PlasmaSol Story” PlasmaSol, the early years: 1999 – 2003 • Chasing SBIRs and contracts • Hovering from grant to grant to make pay roll • No clear business strategy • Just staying afloat

PlasmaSol, the “focus” years: 2003 – 2005 • The hiring of a “business type” as CEO, Frank Shinneman • A focused business strategy, “exit” in 3 years • Only SBIRs aligned with business strategy • Identify strategic partner for joint venture • Stay focused, stay focused, stay focused, …




The “PlasmaSol Story” Stryker-PlasmaSol: From Joint Development to Acquisition

December 2004: – Joint Development (JD) program with Stryker division

February 2005 – Stryker Instruments starts funding JD program

March – August 2005 – Monthly research updates – Stryker feels out PlasmaSol about a possible acquisition

Fall 2005 – Due Diligence – Board members Visit – Division management “sells” idea to Corporate

December 28, 2005: The Deal is Done!




The “PlasmaSol Story”

Time of Sale: • Stage: Development, Pre-Revenue • Technology: Sterilization

– Medical Instrument Sterilization – Air Sterilization

• Employees: 8 • Funding: > $1.5M/yr., Gov’t and other Contracts • IP: 4 US Patents granted +

14 US Applications

Factsheet: • 6 years from Concept to Commercialization to Exit • $2.5M equity financing + $7M R&D funding (via gov’t, etc.) • $20M sale of company + patents (to Stryker Instruments)

Then there was Plasmion - a victim of the “valley of death”







Science breakthrough Engineering realization Bench-scale prototype Technology realization Technology verification, proof-of concept Customer validation Scale-up, economics Large-scale industrial testing Commercialization, industry acceptance

The PlasmaSol Start-up Story

Start-up and IP acquired

Purchaser assumes all further risks !!!

Here: Stryker spent another year on further technology refinement, then shelved the technology, because of corporate restructuring !


The Landscape of Technology Transfer ST

C

SBIR

I/UC

RC

ERC

GO

ALII I-Corps/POCCs

STTR

AIR

/PFI

Ditch of Death

University

Small Business

Industry

Investors

Foundations Valley of Death

Discovery Development Commercialization

Res

ourc

es In

vest

ed

NSF overall

Company Formation

e.g. NSF Programs


Proton Transfer Reaction Mass Spectrometry (PTR-MS) PTR-MS (Proton Transfer Reaction – Mass Spectrometry) enables the real-time measurement of volatile organic compounds, VOCs.

Lab in 1998 Ionicon 2010

Originally developed by scientists at the Institut für Ionenphysik at the University of Innsbruck, Austria, this technology has been commercialized by IONICON Analytik.

1. Standard approach: Collection of samples into vessels (or traps) followed by extraction and separation by a GC column plus detector (e.g. ms) proper use of standards and careful calibration yields very reliable results and allow identification and quantification, but not in real-time !!

2. Alternative: Direct inlet mass spectrometry (DIMS) No sample collection into bags necessary, thus real time analysis however, quantification and identification are a challenge + need to ionize reactant in the sample gas fragmentation



0

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Methanol Ethanol Acetaldehyd

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Häu

figke

it


15 20 25 30 35 40 45 500

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Masse [amu]


Fragmentation via DI:

Electron impact @ 70 eV Charge transfer with Xe+, IE(Xe) > IE(R) Soft and efficient ionization, e.g. PTR-MS PA(H3O) < PA(R)

R + e → R+ + fragment ions

Xe+ + R → R+ + Xe

H3O+ + R → RH+ + H2O

Mass (amu)

Rel

. Abu

ndan

ce



PTR-MS resulted from ion-molecule reaction studies with various techniques in the 1970s and 1980s, in particular

“selected ion flow drift tube, SIFDT” studies

-------------------- A+ → [R] → R+ -------------------- Determination of reaction rate k from: t, R+/A+, [R]

A novel idea proposed in1985: Reversed SIFDT Determination of [R] from k, t, R+

Next step in 1994: Hollow Cathode Discharge + Drift Tube



The technology – ion source principle Hollow cathode discharge: • Water vapor from distilled water reservoir • H3O+ with >99% purity, no mass filter necessary • High primary current, separated from drift tube

e- + H2O H2O+ + 2e- H2

+ + ... H+ + ... O+ + ... H2

+ + H2O H2O + + H2 H+ + H2O H2O + + H

O++ H2O H2O + + O H2O+ + H2O H2O∙H+ + OH



exothermic collisions

H2O∙H+ + C3H6 → C3H6∙H+ + H2O + C6H6 → C6H6∙H+ + H2O + CH3OH → CH3OH∙H+ + H2O + CH3CN → CH3CN∙H+ + H2O + hydrocarbon derivatives →

• Sample gas at 2.2 mbar collides with H3O+ ions • Proton (H+) switches to (and ionizes) sample gas, if proton

affinity is higher than that of water (166.5 kcal/mole)

The technology – drift tube principle

No reaction with O2, CO2, CH4, N2, Ar etc. Reaction with VOCs having a higher proton affinity than H3O+

H3O+ + R → RH+ + H2O

endothermic collisions

+ N2 + O2 H2O∙H+ + Ar + CO2 + CH4



+ +

Water Air

How does PTR-MS work ?



Disadvantages:

PTR-MS – advantages • Short response time: below 100 ms - instantaneous detection • Quantification • Sample gas is measured without preparation - on line • Ultra high sensitivity (< pptv range)

Next Step: Improve selectivity and sensitivity

• In addition to H3O+, use NO+ and O2+ as

reagent ions via HC ion source from ambient air (NO+) or oxygen gas reservoir (O2

+) • O2

+ react via non-dissociative and dissociative charge (electron) transfer

• NO+ react mainly via hydride anion transfer

• Identification is more difficult • Not all compounds are accessible

Also: use of TOF instead of a Quad improves the resolution significantly



Urban air roadside Isobaric compound identification

biogenic compounds (terpene, sesqueterpene) show build up in late afternoon, broad maximum around midnight, minimum next morning exhaust related compounds (benzene, toluene) exhibit traffic related peaks, bimodal peak during morning and evening traffic Sharp spikes: wind gusts

43.0184: protonated ketene 43.0548: protonated propene 47.0133: formic acid 47.0497: ethanol



Food Flavor Analysis:

Espresso

m/z 73 butanone; m/z 75 methylacetate; m/z 81 furfurylalcohol; m/z 83 methylfuran; m/z 87 methylbutanal & diacetyl

Nose space spectra while “tasting” vs “drinking” espresso. The ion mass at m/z 61 corresponds to acetaldehyde.



Food Flavor Analysis: Espresso ≠ Espresso



The history of PTR-MS

1998: Founding of Ionicon as a spin-out company (“garage operation” of a few entrepreneurially-minded academics)

Instrument Sensitivity: 1998: 10 ppmv 2001: ppbv 2010: pptv 2014: a few 100 ppqv

2013: 250 instruments worldwide in operation (team of ~ 25; annual revenue about $8M in 2012/13)



PTR-TOF 1000: smallest, lightest & most affordable PTR-TOF

• Sensitivity: > 40 cps/ppbv (Benzene) • Resolution: > 1500 • Limit of Detection: < 10 pptv

Top of the Line: PTR-TOF 8000 (until now) • Detection limit: < 10 pptv • Sensitivity: > 120 cps/ppbv (Benzene) • Mass Resolution: > 5000 • Full mass range acquisition in a split-second • Linearity range: 6 orders of magnitude (10 pptv - 1 ppmv)

PTR-QiTOF: about to hit the market •Detection limit: < 1 pptv

• Sensitivity: up to 2500 cps/ppbv (Benzene) • Mass Resolution: up to 10,000)










Customer validation

Scale-up, economics



Ionicon Analytik: From breakthrough to full commercialization


~ 15 years


PTR-MS & Ionicon: Academic Entrepreneurship in Motion

STC

SBIR

I/UC

RC

ERC

GO

ALII I-Corps/POCCs

STTR

AIR

/PFI

Ditch of Death

University

Small Business

Industry

Investors

Foundations Valley of Death

Discovery Development Commercialization

Res

ourc

es In

vest

ed

NSF overall

Company Formation

e.g. NSF Programs

Ionicon

Technological Applications of (Atmospheric … › ~bonitz › si14 › download › slides › ...Technological Applications of (Atmospheric -Pressure) (Micro)Plasmas: Opportunities

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