R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 1
Environmental Aspects of
Plasma Science
Dr. Ronny Brandenburg, Prof. Klaus-Dieter Weltmann
INP Leibniz Institute for Plasma Science and Technology
Felix-Hausdorff-Straße 2,
17489 Greifswald, Germany
Fon: +49 - 3834 - 554 446, Fax: +49 - 3834 - 554 301
mailto: brandenburg@inp-greifswald.de
web: www.inp-greifswald.de
FROM THE IDEA TO THE PROTOTYPE
2
Content
1. Introduction
- Plasma technology as an environmental technology
2. Exhaust treatment by non-thermal plasmas - Basics
- Gas discharges for exhaust treatment
- Discharge physics and plasma chemistry
- Example for plasma chemistry: Ozone synthesis
- Hybrid processes
- Flue gas treatment (NOx and SOx removal)
- VOC-removal
- Particulate matter removal
3. Water treatment
- Advanced Oxidation
- Electro-hydraulic discharges
- Antimicrobial treatment by indirect treatment of liquids
4. Summary and Outlook
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 2
3
Plasmas for environmental protection
EU-Project “PlasTEP”
Project with 14 partners from the
Baltic Sea Region with the aim of
dissemination and fostering of plasma
based technological innovation for
environment protection in the Baltic
Sea Region
New possibilities fostering of innovative plasma-based
exhaust gas and water treatment techniques
Sustainability analysis of plasma-based environmental
protection
3 thematic working groups: NOx/SOx; VOCs; polluted water
www.plastep.eu
3
4
Waste incineration
Thermal plasma for burning of solid waste and hazardous gases
Energy and ressource saving technologies
Substitution of wet chemical processes (surface processing)
Use of solvent free products due to surface treatment
Depollution technologies
Decomposition of pollutants
Filtering of PM (Electrostatic precipitators)
Plasma based generation of active compounds
Ozone for water treatment or chloride-free bleaching
Efficient lightsources
Energy saving due to efficient light generation
Plasma based UV-lightsources for surface processing and curing etc.
Plasma Technology = Environmental technology
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 3
5
Emission sites and effects
Kim, AIST JPN
SOx
Soil
Air
Water
VOC-decomposition and deodorization methods
1 TO, Thermal Oxidation
2 RTO, Regenerative Thermal
Oxidation
3 Catalytic Oxidation with
Recuperation
Thermal Processes
Filtering/Adsorption
4 Biofilters
5 Scrubber
7 Adsorption Container
8 Concentrator Unit with TO
9 Filtering
6a Electrical Non-thermal oxidation
6b UVS Non-thermal Oxidation
Non-thermal
Oxidation
Haus der Technik, Essen/GER
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 4
8
Content
1. Introduction
- Plasma technology as an environmental technology
2. Exhaust treatment by non-thermal plasmas - Basics
- Gas discharges for exhaust treatment
- Discharge physics and plasma chemistry
- Example for plasma chemistry: Ozone synthesis
- Hybrid processes
- Flue gas treatment (NOx and SOx removal)
- VOC-removal
- Particulate matter removal
3. Water treatment
- Advanced Oxidation
- Electro-hydraulic discharges
- Antimicrobial treatment by indirect treatment of liquids
4. Summary and Outlook
Gas discharges for exhaust treatment
Barrier discharge Corona
Gas
Grounded electrodeWire electrodeGrounded electrode
Dielectric electrode
High voltage
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 5
1010
Stack system with structured electrodes
Electrode
Isolator plate
S. Müller, R.-J. Zahn; Contributions to Plasma Physics 47 (2007) 520-529
Stack reactor (Barrier discharge)
11
Surface
Discharge
Gas
S. Müller, R.-J. Zahn, J. Grundmann; Plasmas and Polymers 4 (2007) S1004
Open System Gas redirection system
Surface DB with ion-extraction
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 6
12
(Corona) radical shower
Applied in particular to NOx-removal
Plasma treats only a portion of gas
flow, creating active species, which
then treat the total gas flow as a
„shower“
Chang et al, MacMaster Univ. CAN
13
Packed bed reactors
Filling:
Pellets
Foams
M. Kraus et al, ABB
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 7
14
Processes and time scales
Plasma chemistry based on non-thermal activation of particles via
collisions
quality and quantity determined by kinetic parameters (vmean, νcoll)
possible mechanisms
with different probability
(different energy thresholds)
3 ... 10 eV for dissociation and radical
formation
> 10 eV for ionisation
E/n
Plasmaphysics
Plasma chemistry
time
in sEnergy
distribution of
electrons
Ionisation
Dissociation
Excitation
Attachment
Charge
exchange
Ion reactions
Reactions of/with active
species
Reactions of/with radicals
Diffusion
Heat and mass transfer
10-12 10-10 10-9 10-8 10-7 10-6 10-5 10-4 10-3 10-1 10
15
Air chemistry in cold non-thermal plasma
U. Kogelschatz, B. Eliasson
Homogeneous model (143 reactions, 30 reacting species)
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 8
16
Hirth et. al; J. Phys. D. (1986)
ChemistryDischarge
Ozone synthesis
Aerosol particle formation
Reactions of larger radicals (CHO, CHN) with
cluster ions and molecules
Generation of nitric acid (HNO3) reaction
with radicals
Promotion of
VOC removal
due to heterogeneous
reactions
Kim, Plasmas and Polymers
2004
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 9
18
2NO NO
3 2
HNO
+ O
+ OH + OH
2
; + O
2
+ N
+ O
N
;+HO + OH
HNO3
N
NO3 N
O2
2O5
+ O
+ N
NO2
Oxidative pathways dominate (espacially in case of
humid conditions)
Reduction at (to) high energy input
NOx-conversion
VOC removal reactions
Saturated Hydrocarbons (e.g. alkane):
Dehydro- R-H + O R + OH
genization R-H + OH R + H2O R• ... organic radical
Oxidation R + O2 R-O-O R-O-O ...peroxy radical
Further oxidation
to CO2 and H2O
Radical chain
reaction
Ra-O-O + Rb-H RaOOH + Rb
ROOH ... alkyl hydroperoxide
Free electrons: e- + {O2, H2O, ...} OH, M+ HO2, O3
Unsaturated Hydrocarbons (e.g. alkane):
Additionally radical addition following oxidation,
radical chain reaction or polymerisation of hydrocarbons
10 – 30 eV/OH-radical
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 10
20
Example: Formaldehyde (CH2O)
destruction of CH2O results dominantly from chemical attack
by OH and O radicals
primary end products: CO, H2O
destruction rates typically 2-8 ppm/(1 J/l)
Storch and Kushner, J. Appl. Phys. 1993
21
NTP vs. RTO
Fridman, Drexel University
NTP-VOC
removal:
10 – 30 eV/VOC-molecule
Regenerative
Thermal Oxidation
(RTO):
0.1 eV/molecule
per molecule of air
Lower energy consumption in NTP if VOC-concentration
> 0.3 … 1% (3.000 – 10.000 ppm)
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 11
22
Evaluation
Specific Energy Density SED (J/L) = Pdis / Q
(Spec. Input Energy SIE)
CO2-Selectivity SCO2
Carbon balance CB
Decomposition efficiency η
(Destruction and removal
efficiency, DRE) [VOC]0 … inlet concentration;
n … number of C-atoms
Pdis … dissipated plasma power; Q … gas flow
Kim, Plasmas and Polymers 2004
23
Energetic efficiency
∆[C] … removed amount of molecules in ppm
Kim, Plasmas and Polymers 2004
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 12
24
Evaluation: SED-plots
[VOC] = [VOC]0 exp(-SED/β) SED = -β ln([VOC]/[VOC]0
SED
SED
1/ββββ = kE ... energy constant
kE = f( Temp, gas comp., [VOC]0, ...)
Veldhuizen, TU Eindhoven
25
Energy cost
Energy Price significantly depends on initial concentration
Few ppm: energy price reaches very high values (not all active species can
target VOC molecules)
Higher concentrations: fraction of energy for removing pollutant molecules
higher and energy spent for elimination of each single molecule decreases
Gutsol and Fridman, Drexel University
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 13
Depollution of gases
- High energy cost/molecule high energy for high concentrations
- Uncompleted conversion and by-products low selectivity (CO2)
- Deposition of polymer films in reactors unstable plasma source
+ Decomposition of contaminants without heating
+ Wide range of pollutants (Gases ... Particulate Matter PM)
+ Decomposition of organic PM
+ High efficiency for low contamination (e.g. deodorization)
([VOCs] < 1 g Corg/m3)
Possibilities
Indirect treatment (Bypass installations)
Hybrid methods = combination of plasma with ...
... catalysts
... scrubbing
... adsorbents Heterogeneous reactions
and synergies!
27
Hybrid NTP / Wet Processes
Removal of reaction intermediates or final products from
gas phase by adsorption and/or chemical reaction
Gas-phase NTP enhance liquid-phase chemical reactions
Electrical discharge over a liquid surface modify masstransfer
characteristics
Kim, AIST JPN
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 14
Falling water BD-reactor
Page 28 V. Kovacevic, M. Kuraica; Belgrade University
Water flows up through vertical hollow cylindrical electrode
and flows down making thin water film over high voltage
electrode
treatment of water (dyes)
treatment of gas phase combined with scrubbing
Removal of undecane (non-soluble) scrubbing of by-product (formic acid)
w/o water
With water
2929
Plasma and catalyst: shift of temperature range
Whitehead et al, Manchester Uni.
Dichlormethane (DCM) decomposition
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 15
Overall process of plasma based removal
Barrier discharge (Mikro discharges)
1. Breakdown phase (ps … ns)
Ionisation, Dissociation, Excitation … Ions, Electrons & Radicals
2. Reaction phase (µs … ms)
Recombination and conversion of ions and radicals
(primary radicals OH, O sekundary radicals O3, HO2, …)
Oxidation of pollutants Schadstoffe
Surface reactions (activation, structural changes)
3. Post phase (ms … s)
Diffusion, transport of heat and material, chemical reactions with post reactants
Aerosol formation
Adsorption
Gas
Post-treatment
Gas Gas
Scrubber, Catalyst,
Adsorber
Electron beam flue gas treatment (EBFGT)
A.G. Chmielewski et al; INCT Warschau; Kraftwerk “Pomorzany” Stettin/PL 31
270.000 Nm3/h of flue gas
SO2 removal efficiency above
95%
NOx removal efficiency above
70%
Dose up to 10 kGy
NO NO2 HNO3 NH4NO3
SO2 HSO3 H2SO4 (NH4)2SO4
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 16
32
A. Chmielewski et al., ICHTJ Warzsawa
EBFGT removal efficiency
Ozone injection: non-thermal oxidation
E. Stamate et al.; Fuel 2010
N2O5 HNO3
HNO3 NaNO3
H2O
NaOH
HCl
SO2 Na2SO4
NaOH NaCl
NOx Reactor
NO & O3 … N2O5
Scrubber
Ozoniser
O2
O3
H2O
Na2SO4
NaCl
NO
SO2 N2O5
Cleaned emissions
33
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 17
LOTOX (Low Thermal Oxidation) & EDV Scrubbing
Belco/Dupont
34
NO, NO2 conversion
to N2O5
SO2 & PM removal
PM 2.5 removal
Water droplet separation
Ozon
Injection
N2O5 conversion to
HNO3
Plasma-unterstützte Katalyse (NH3-SCR)
S.M. Young; Plasma Sci. Technol, 2006
CTOHNNHNONO
CTOHNONHNO
°≤+→++
°≥+→++
100;322
200;6444
2232
2223
[ ] [ ]2NONO ≅wenn:
35
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 18
3636
Plasma-enhanced SCR (selective catalytic reduction)
T. Hammer; Plasma Sources Sci. Technol. 2002
up to 85% NOx reduction under cold start and urban driving conditions
less than 300 W of plasma power applied
model studies: fuel penalty introduced estimated to be below 2%.
Volume Barrier Discharge comb. with urea-SCR
37
Multi-stage treatment with molecular sieves
R. Rafflenbeul, Envisolve.com; Germany
1. Enrichment of high-molecular compounds in molecular sieve buffer
2. Oxidation of odours with a plasma stage
3. Expellation with desorption air combustion of VOC contingents with
catalyst (after sev. months of molecular sieve loading)
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 19
38
Bypass operated plasma plants
R. Rafflenbeul, Envisolve.com; Germany
• Indirect plasma treatment of polluted gas by plasma treated
gas
39
Deodorization unit (commercial)
Kim, AIST Japan
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 20
40
PlasmaNorm-Technology
Deodorization of exhaust
from ovens for
convenience products
made of meat
(1.5 MW ovens; exhaust
stream of 8000 Nm3/h)
Cooker hoods for large-scale
kitchens, gastronomy and private
hausholds
M. Langner; Airtec competence GmbH
41
A. Fridman, A. Gutsol (Drexel) 2005
Mobile laboratory for paper/pulp mills
10 kW
750 m3/h
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 21
4242
A. Mizuno, Plasma Phys. Control. Fusion 49 (2007) A1–A15
Pilot plant for H2S removal
43
Process features
Kim, AIST Japan
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 22
44
Economical benefit
R. Rafflenbeul, Envisolve.com; Germany
Plasma & Catalyst
Chen et al., Environ. Sc. Technol. 43 (2009) 2216; Van Durme et al., Appl. Catal. B 78 (2008) 324
45
Plasma
Adsorption of pollutants
Electric field enhancement
Catalyst
Enhancement of retention
time and concentration
Increase of electron
temperature and density
Voltage potential across
Local heating
Active species
Increase of work function
Surface regeneration
Enhance dispersion of active
components
Change of oxidation stage
Formation of active sites
Increase of surface area
Enhance energy efficiency Improve selectivity Extend cat. durability
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 23
46
Soot removal
BD-reactor with porous filter electrode
J. Grundmann, S. Müller, R.-J. Zahn; Plasma Chem. Plasma Process. 25 (2005)
Patente WO 2005/028081, DE 197 17 890, ...
4747
Soot Soot-O
Soot-NO2
CO / CO2
+ NO2;
+ NO3
+ O3 (+ O3)
+ O3; + NO;
+ NO2; + NO3
J. Grundmann, S. Müller, R.-J. Zahn; Plasma Chem. Plasma Process. 25 (2005)
(1) fast reaction with HC
(2) forming of Soot-O
(3) decomposition of Soot-O
Soot-removal
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 24
Plasma Regenerated Diesel Particle Filter (DPF)
M. Okubo et al.; Thin Solid Films, 2006
NO2 and O3
incineration with direct
NTP reactor
(Tg > 200 °C)
NO2 and O3
incineration with
indirect NTP reactor
(Tg > 200 °C)
)23(
)200(22
22
1
23
22
CTOCOOC
CTNOCONOC
°>+→+
°>+→+
223 ONOONO +→+
48
49
Content
1. Introduction
- Plasma technology as an environmental technology
2. Exhaust treatment by non-thermal plasmas - Basics
- Gas discharges for exhaust treatment
- Discharge physics and plasma chemistry
- Example for plasma chemistry: Ozone synthesis
- Hybrid processes
- Flue gas treatment (NOx and SOx removal)
- VOC-removal
- Particulate matter removal
3. Water treatment
- Advanced Oxidation
- Electro-hydraulic discharges
- Antimicrobial treatment by indirect treatment of liquids
4. Summary and Outlook
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 25
5050
Water treatment - Overview
Water cleaning
Physical
methods
Biological
methods
Chemical
methods
Sedimentation
Filtering
Flotation
Biochemical Ox.
Anaerobic cleaning
Oxidation
Disinfection
Plasma
5151
Water treatment - Overview on plasma methods
Gas in
Remote
treatment
UV-
treatment
Indirect
plasma
treatment
Direct
plasma
treatment
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 26
5252
Indirect plasma treatment
Use of “classical gas discharge” for water
treatment, no special efforts (power supply,
independent on water conditions, …)
Indirect interaction of atmospheric
pressure plasma with liquids mainly based
on reactions at gas/plasma-liquid interface
Bulk effects based on diffusion processes
Biological (bactericidal) effects of plasma
treatment mainly based on changes of
liquid: resulting in generation of more or
less stable reactive species
53
5. Water treatment
Bulk effects by indirect treatment
Generation of nitrite
(Spectroquant® – nitrite test)
Generation of H+ →→→→ pH change
(methyl orange as pH indicator)
0 min
Phases of spreading:
spreading phase
formation of a diffusion
front
surface reaction
directed gas phase-liquid
interaction
Diffusion influenced
by gradients
e. g. temperature,
magnetic fields
„Drop and structure
formation“
10 min 20 min
0 min 10 min 20 min
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 27
54
Indirect treatment of non-buffered liquid
Inactivation of suspended vegetative microorganisms
1,00E+00
1,00E+01
1,00E+02
1,00E+03
1,00E+04
1,00E+05
1,00E+06
1,00E+07
1,00E+08
0 5 10 15 20 25 30
treatment time [min]
numberofviablemicroorganisms
detection limit
10
9
108
107
106
105
10
4
103
10
2
101
100
K. Oehmigen et al., Plasma Process. Polym. 7 (2010) 250-257
E. coli
0,0
20,0
40,0
60,0
80,0
100,0
120,0
0 5 10 15 20 25 30
treatment time [min]
concentrationofnitrate
[mg/l]
0,0
5,0
10,0
15,0
20,0
0 5 10 15 20 25 30
treatment time [min]
concentrationofhydrogenperoxide
[mg/l]
0,0
0,5
1,0
1,5
2,0
0 5 10 15 20 25 30
treatment time [min]
concentrationofnitrite
[mg/l]
2,00
3,00
4,00
5,00
6,00
7,00
8,00
0 5 10 15 20 25 30
treatment time [min]
pH
pH NO3
-
NO2
-
H2O2
Acidification and generation of nitrate, nitrite (peroxynitride) and hydrogen peroxide
Plasmas in Water
High but pulsed electric field strenght and pulsed discharge in water enable
fast and efficient biological and chemical decontamination without additional
chemistry
Effects due to electric field, radiation (UV), radicals and schock waves
Dependent on puls parameters: temporal inactivation or killing
J. Kolb, INP Greifswald/ODU Norfolk
1cm
R. Brandenburg (INP Greifswald), Innolec
Lectureship Brno 2012
Part 3: Environemntal aspects 28
5959
Summary and Outlook
Plasma technolgy is (already) an environmental technology at all!
NOx, SOx, VOCs and other gaseous contaminants can be
decomposed in non-thermal plasmas (NTPs) via „radical based“
plasma chemistry.
Exhaust treatment by means of NTP is especially suited for low
concentrations in small and medium gas flows.
Applicability/feasibility is determined by the specific situation (type
and amount of contaminants, properties of gas flow) and has to
consider effectivity and selectivity.
There is a large potential for hybrid/catalytic/heterogenous methods.
Generation of plasma at or in water is possible and leads to
antimicrobial and chemical effects.
60
See you Lituania
Apply now for the 3rd PlasTEP summer school
and entrepreneurs' course in Vilnius/ Kaunas
16.07. - 27.07.2012
http://www.plastep.eu/english/newsdetails/einzelansicht/article/60/
Participants that are leaving at the end of the twelfth day
will have developed a network of contacts in the field of
plasma technologies and environmental protection and
will have gained a broad overview of the issues
surrounding sustainable environmental technologies
development and implementation
The participation and accomodation for summer
school students is free of charge!