1 pm removal system for diesel passenger vehicle using non-thermal plasma kazuhiko madokoro, y. h....
TRANSCRIPT
1
PM REMOVAL SYSTEM FOR DIESEL PASSENGER VEHICLEUSING NON-THERMAL PLASMA
PM REMOVAL SYSTEM FOR DIESEL PASSENGER VEHICLEUSING NON-THERMAL PLASMA
Kazuhiko Madokoro, Y. H. Kim, K. Naito, T. OgawaH. Fujikawa, K. Hasegawa, H. Tanaka
Research Institute of Innovative Technology for the Earth (RITE), Japan
S. Yamamoto, S. Kodama, C. MineS. Yao, Y. Fujioka
Daihatsu Motor Co., Ltd., Japan
S. Soma, T. Nakajima, G. SugiyamaJapan Automobile Research Institute (JARI), Japan
2
Introduction
- Diesel emission regulations
- What is plasma?
- Advantages and problems of plasma technology
Experimental
Results
Conclusion
OutlineOutline
3
Diesel emission regulations (Passenger vehicles)Diesel emission regulations (Passenger vehicles)
USUSEUEUJapanJapan
0.00
0.02
0.04
0.06
0.08
0.10
0.0 0.2 0.4 0.6 0.80.14 0.40.28
0.052
0.013
1997
2002
2005
2009
PM
[g
/km
]
0.080
0.005 0.08
NOx [g/km]
11, 10 ・ 15 , JC08 mode
Our target
0.00
0.02
0.04
0.06
0.08
0.10
0.0 0.2 0.4 0.6 0.80.00
0.02
0.04
0.06
0.08
0.10
0.0 0.2 0.4 0.6 0.8
0.05
0.025
0.005 0.50.18 0.25
2005 Euro4
2000 Euro3
1994 Tier1
2004 ~ 06 Tier2 (Bin#9)
2007 Tier2 (Bin#5)
0.062
0.037
0.006
0.044 0.780.19
2009 Euro5
NEDC mode FTP mode
NOx [g/km] NOx [g/km]
Stricter regulations for emission control are being set all over the world. The Japanese post new long-term emission regulation comes into force.
A newly established emission test mode (JC08) has also been introduced.
0
20
40
60
80
0 200 400 600 800 1000 1200
Elapsed time [ s ]
Veh
icle
spe
ed [
km/h
]
Japanese JC08 Japanese JC08 modemode
4
Plasma is called a "Fourth State of Matter". Plasma is a partially ionized gas mixture and contains electrons, ions, neutral atoms,
molecules, reactive free radicals and photons.
Liquid GasMelting Evaporati
on
PlasmaElectrolyticdissociation
Solid
Fourth stateThree states of matter
Exhaust gases
O2, NO, H2Oetc
O3, O, NO2
etc
Discharge plasma
PM
It is generally known that highly reactive species such as O3, O, NO2 and OH are generated in the plasma of diesel exhaust gases. These reactive species can lead to oxidation of PM.
CO2
CO
Application of the plasma to diesel exhaust Application of the plasma to diesel exhaust gasesgases
Lightning Aurora
What is Plasma ?What is Plasma ?
5
Successive PM removal irrespective of ambient temperature No using Platinum-Group Metals Easily controllable of PM removal rates by power management Simple reactor configuration for low pressure drop
Designing of a novel plasma reactor Reduction of energy consumption Improvement of power supply system & power delivery for plasma generation Elucidation of PM removal mechanism Durability of the system
AdvantagesAdvantages
Hurdles to overcome before practical useHurdles to overcome before practical use
Advantages and problems of plasma technologyAdvantages and problems of plasma technology
PM emission : below 0.005 g/kmPM emission : below 0.005 g/km Pressure drop: below 5 kPaPressure drop: below 5 kPa Fuel penalty : below 2.5%Fuel penalty : below 2.5% (at Japanese JC08 mode) (at Japanese JC08 mode)
TargetTarget
6
Introduction
Experimental
- Discharge system
- Emission measurement system
- Modal emission test
Results
Conclusion
OutlineOutline
7
Discharge systemDischarge system
Oscilloscope
AC 100V Plasma Reactor
High voltage probe
Current Transformer
Pulse PowerSupply
DC PowerSupply
Dielectric barrier discharge reactorDielectric barrier discharge reactordriven by high-voltage pulsesdriven by high-voltage pulses
Discharge
Ref: S. Yao (RITE), AIChE J., Vol. 53, 1891-1897 (2007)
8
Non-thermal plasma reactorNon-thermal plasma reactor
Dielectric plate Electrode
Highvoltage
Earth
Dielectric (General flat plate of alumina)
Electrode
Gas flow
CO2
(CO)
Temporary trapOxidation
(Combustion)
PM(c)
Gas flow
9
Dilution Air
Samplingbag
PM filter
CFV-CVS
Engine Exhaust Particulate Sizer(EEPS-3090)
Full flow dilution tunnel
Emission measurement systemEmission measurement system
Dilutor
Chassis dynamometer
Particle numberParticle numberconcentrationconcentration
PM mass emissionPM mass emission
Engine 1.5 L 4-cycle diesel engine
Original Emission level Euro4
Original aftertreatment Diesel oxidation catalyst (DOC)
Vehicle data
Vehicle emission measurement was carried out at JARI.
Soluble organic fraction (SOF)Insoluble organic fraction (ISF)
Soxhlet extraction
10
0
20
40
60
80
100
120
-200 0 200 400 600 800 1000 1200
Elapsed time [ s ]
Ve
hic
le s
pe
ed
[ km
/h ]
Warm-up period
Cold mode start (without warm-up)
Emission measurement start
Modal emission testModal emission test
Hot mode start
Japanese JC08 mode (hot and cold Japanese JC08 mode (hot and cold start)start)
Evaluated aftertreatment systemEvaluated aftertreatment system
EngineEngine Without aftertreatment
Original aftertreatment (DOC) DOC
EngineEngine
Original & Plasma reactor
DOC
EngineEngine Plasmareactor
11
Introduction
Experimental
Results
- Inlet gas temperature of the plasma reactor
- PM mass emission
- Particle size distributions
- Appearance of alumina plates
- Pressure drop of plasma reactor
Conclusion
OutlineOutline
12
Inlet gas temperature of the plasma reactorInlet gas temperature of the plasma reactor
Inlet gas of the plasma reactor was under low temperature Inlet gas of the plasma reactor was under low temperature during mode.during mode.
Hot start mode Maximum : 222.6 ºC Average : 170.4 ºC
Cold start mode Maximum : 222.0 ºC Average : 147.0 ºC
Gas temperature
0
20
40
60
80
100
Veh
icle
spe
ed [
km
/h ] Target vehicle speed
Real vehicle speed
0
50
100
150
200
250
0 200 400 600 800 1000 1200
Elapsed time [ s ]
Gas
tem
pera
ture
[ °
C ]
hot
cold
13
0.00
0.01
0.02
0.03
0.04
0.05
0.06
PM SOF ISF
Em
issi
on
[ g
/km
]
w/o aftertreatmentOriginalOriginal & Plasma
PM SOF ISF
w/o aftertreatmentOriginalOriginal & Plasma
PM SOF ISF
w/o aftertreatmentOriginalOriginal & Plasma
PM mass emissionPM mass emission
Cold Hot Combine*
* Combine emission = Cold mode emission × 0.25 + Hot mode emission × 0.75
51% 62%59%
86% 93% 91%81%86% 8
4%
15%26% 23%
Japanese new regulation(JP 2009)
The plasma reactor showed almost same removal capability in The plasma reactor showed almost same removal capability in both modes.both modes. The oxidative ability of plasma showed elective affinity for soot.The oxidative ability of plasma showed elective affinity for soot. PM emission of our plasma reactor achieved JP2009 regulationPM emission of our plasma reactor achieved JP2009 regulation
(combine emission value 0.0048 g/km).(combine emission value 0.0048 g/km).
79%79%
77%
54%23% 35%
91%(0.0048 g/km)
14
1 10 100 1000
Particle size [ nm ]
0.E+00
1.E+06
2.E+06
3.E+06
4.E+06
5.E+06
6.E+06
7.E+06
8.E+06
9.E+06
1.E+07
1 10 100 1000
Particle size [ nm ]
Par
ticle
con
cent
ratio
n [
#/cm
3 ]Particle size distributionsParticle size distributions
Cold Hot
Particle concentrations after the plasma reactor were clearly reduced. Particle concentrations after the plasma reactor were clearly reduced. Non-thermal plasma could also remove nano-particles.Non-thermal plasma could also remove nano-particles.
Good
87.6%81.3%
w/o aftertreatment
Original
w/o aftertreatment
Original
w/o aftertreatment
Original
Original & Plasma
w/o aftertreatment
Original
Original & Plasma
15
Without plasma With plasma
Area of electrode
Temporarytrap
Oxidation(Combustion)
Appearance of alumina platesAppearance of alumina plates
After about 300 km mode driving
PM was clearly removed on the alumina plate with plasma.PM was clearly removed on the alumina plate with plasma. PM adsorption was observed less at downstream side. PM adsorption was observed less at downstream side. It is suggested that reactive species which came from the It is suggested that reactive species which came from the upstream side upstream side contributed to oxidize PM at the downstream side. contributed to oxidize PM at the downstream side.
Exh
au
st g
as
flow
16
Pressure drop of the plasma reactorPressure drop of the plasma reactor
The plasma reactor maintained lower pressure drop during consecutive The plasma reactor maintained lower pressure drop during consecutive mode tests.mode tests. It is suggested that PM was successively removed by the plasma reactor.It is suggested that PM was successively removed by the plasma reactor.
0
1
2
3
4
5
0 200 400 600 800 1000 1200Elapsed time [ s ]
Pre
ssu
re d
rop
[ kP
a ]
0
20
40
60
80
100
Ve
hic
le s
pe
ed
[ km
/h ]
.
Hot
Cold
Vehicle speed
0
1
2
3
4
5
6
7
8
0 5 10 15Number of mode test [ n ]
Ma
xim
um
pre
ssu
re d
rop
[ kP
a ]
.
17
ConclusionConclusion
1. PM emission could satisfy JP2009 emission regulation of 0.005 g/km by installing the plasma reactor after the original DOC.
The plasma reactor showed successive high removal rate for ISF which is not easily oxidized with catalytic reactions compared with SOF.
2. The plasma reactor could remove PM under low temperature. Such a removal ability is a great advantage compared with a catalyst or a DPF which requires active regeneration.
3. The plasma reactor showed low pressure drop during JC08 mode. Such low pressure drop was achieved due to the structural characteristic
of plasma reactor.
This plasma system is expected to be one of the This plasma system is expected to be one of the
promising technologies for diesel emission control.promising technologies for diesel emission control.
18
AcknowledgementAcknowledgement
This work is supported by This work is supported by
Japanese government through NEDO.Japanese government through NEDO.
New Energy Industrial Technology Development Organization
Thank you for your Thank you for your attention !attention !
Thank you for your Thank you for your attention !attention !
We would like to thank We would like to thank
Professor Yoshimasa NiheiProfessor Yoshimasa Nihei [Tokyo University of Science] [Tokyo University of Science]Professor Hajime FujimotoProfessor Hajime Fujimoto [Doshisha University] [Doshisha University]Professor Yoichi HoriProfessor Yoichi Hori [The University of Tokyo] [The University of Tokyo]Professor Yasutake TeraokaProfessor Yasutake Teraoka [Kyushu University] [Kyushu University]
Comprehensive Technological Development of Innovative, Next-Generation,Low-Pollution Vehicles R&D of Innovative After-Treatment Systems
19
END END
20
NOx emissionNOx emission
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
NOx CO NMHC
Em
issi
on
[g/k
m]
w/o aftertreatment
DOC
DOC & Plasma
NOx CO NMHC
w/o aftertreatment
DOC
DOC & Plasma
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
NOx CO NMHC
Em
issi
on
[ g
/km
]
w/o aftertreatment
DOC
DOC & Plasma
Cold Hot
Combine
21
Discharge systemDischarge system
Oscilloscope
AC 100V Plasma Reactor
High voltage probe
Current Transformer
Pulse PowerSupply
DC PowerSupply
DC powersupply(DC voltage : 0-600V)
Pulse power supply driven by DC power supply(Pulse peak voltage : ~ 10kV)
22
Electrode
Dielectric
Electrode
Gas flow
Gas flow Gas flow
Glass wool spacerNew electrode
Alumina plate(dielectric)
Discarge
PM
(Mass-produced flat plate of general alumina)
Plasma reactor and new electrodePlasma reactor and new electrode
Ref: S. Yao (RITE), AIChE J., Vol. 53, 1891-1897 (2007)
23
Thermal plasmaThermal plasma : All particles are in state of high temperatures. : All particles are in state of high temperatures.
Gas show high temperatures.Gas show high temperatures. Non-thermal plasmaNon-thermal plasma : Only electrons show high temperatures. : Only electrons show high temperatures.
Gas remains in state of almost 'cold' (ambient temperature).Gas remains in state of almost 'cold' (ambient temperature).
0 5 10 15 20101
102
103
104
105
106
Gas
Tem
pera
ture
Ris
e [C
]
Electron Temperature [eV]
RFJet
ne ~ 1018cm-3
ne ~ 1015cm-3
ne ~ 1012cm-3
Arc
MW Torch
Line of Tgas Telectron
ne ~ 1012cm-3
Pulsed Corona & DBD
MH Cho, postech, 8th APCPST, 2006
Pulsed Corona(+)
cylinderbarrierrodwire cylinder
Dielectric Barrier
Discharge
Thermal and Non-thermal plasmaThermal and Non-thermal plasma
24Our concept for reducing each emissionsOur concept for reducing each emissions
2CD
PlasmaReactorDOC
Cooled EGR
NOx reduction
Soot and SOF reduction
CO, HC and SOF reduction
NOxcatalyst
NOx reduction
NOx is reduced by control of engine combustion or NOx catalyst.NOx is reduced by control of engine combustion or NOx catalyst. CO, HC and SOF are reduced by the diesel oxidation catalyst.CO, HC and SOF are reduced by the diesel oxidation catalyst. Soot and SOF are reduced by the plasma reactor.Soot and SOF are reduced by the plasma reactor.
25Equation for PM removal ratesEquation for PM removal rates
Emission w/ oaftertreatment
ー Original orOriginal & Plasma emission
Emission w/ o aftertreatment
× 100 (%)
PM removal ratefrom emission w/o aftertreatment
=
Original DOCemission
ー Original & Plasmaemission
Original DOC emission
× 100 (%)
PM removal ratefrom original DOCemission
=
26PM number emission (CPC)PM number emission (CPC)
0.E+00
1.E+13
2.E+13
3.E+13
4.E+13
5.E+13
6.E+13
7.E+13
8.E+13
9.E+13
w/o DOC DOC &Plasma
PM
nu
mb
er
Em
issi
on
[ #
/km
]
w/o DOC DOC &Plasma
0.E+00
1.E+13
2.E+13
3.E+13
4.E+13
5.E+13
6.E+13
7.E+13
8.E+13
9.E+13
w/o DOC DOC &Plasma
PM
nu
mb
er
Em
issi
on
[ #
/km
]
Cold Hot
Combine
27
Japanese 10-15 mode and JC08 modeJapanese 10-15 mode and JC08 mode
0
20
40
60
80
0 200 400 600 800 1000 1200
Elapsed time [ s ]
Ve
hic
le s
pe
ed
[ km
/h ]
0
20
40
60
80
0 200 400 600 800 1000 1200
Elapsed time [ s ]
Ve
hic
le s
pe
ed
[ km
/h ]
Japanese JC08 modeJapanese JC08 mode
Japanese 10-15 modeJapanese 10-15 mode
28
0
1
2
3
4
5
0 200 400 600 800 1000 1200
Elapsed time [ s ]
Pre
ssur
e dr
op [
kP
a ]
hot
cold
Gas temperature and pressure dropGas temperature and pressure drop
The plasma reactor could remove PM effectively even under low temperatures.The plasma reactor could remove PM effectively even under low temperatures. The plasma reactor showed lower pressure drop below 3.8 kPa during mode. The plasma reactor showed lower pressure drop below 3.8 kPa during mode.
0
20
40
60
80
100
Veh
icle
spe
ed [ k
m/h
]
Target vehicle speedReal vehicle speed
0
50
100
150
200
250
Gas
tem
pera
ture
[ °
C ]
hot
cold
Cold start mode Maximum : 222.0 ºC Average : 147.0 ºC Hot start mode Maximum : 222.6 ºC Average : 170.4 ºC
Gas temperature
Cold start mode Maximum : 3.4 kPa
Hot start mode Maximum : 3.8 kPa
Pressure drop
29PM mass emission (JP2009)PM mass emission (JP2009)
0.00
0.01
0.02
0.03
0.04
0.05
0.06
PM SOF ISF
Em
issi
on
[ g
/km
]
w/o aftertreatmentOriginalOriginal & Plasma
PM SOF ISF
w/o aftertreatmentOriginalOriginal & Plasma
PM SOF ISF
w/o aftertreatmentOriginalOriginal & Plasma
Cold (JC08)
Hot (10-15) Combine*
* Combine emission = JC08 Cold mode emission × 0.25 + 10-15 Hot mode emission × 0.75
Japanese new regulation(JP 2009)
Combine emission value0.0038 g/km
30
0
20
40
60
80
100
Veh
icle
spe
ed [ k
m/h
] Target vehicle speedReal vehicle speed
0.0E+00
5.0E+05
1.0E+06
1.5E+06
2.0E+06
2.5E+06
3.0E+06
3.5E+06
0 200 400 600 800 1000 1200
Elapsed time [ s ]
Tot
al c
once
ntra
tion
[ #/
cm3 ] w/o aftertreatment
Original
Original + DBD (200W)
Total particle concentrationsTotal particle concentrations
31
Fluctuation of pressure drop during mode testsFluctuation of pressure drop during mode tests
Maximum pressure drop didn't increase during consecutive Maximum pressure drop didn't increase during consecutive mode tests.mode tests. It is suggested that PM was successively removed by the plasma It is suggested that PM was successively removed by the plasma reactor.reactor.
0
1
2
3
4
5
6
7
8
0 5 10 15
Number of mode test [ n ]
Ma
xim
um
pre
ssu
re d
rop
[ kP
a ]