high performance scr technology with ultra-low-nox emissions … · 2015-03-11 · high performance...
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High Performance SCR Technology with Ultra-Low-NOxEmissions for Future Regulations
Emitec Gesellschaft für Emissionstechnologie mbH
Klaus Müller-HaasOswald Holz
CTI, Emission Reduction for Off Highway Applications26.-27.9 2012, Lindau am Bodensee (Germany)
Agenda
Introduction
Challenges to achieve high efficient SCR
SCR Dosing System
Evaporation and Mixing Pipe
Close coupled compact SCR-System
Conclusion
Heavy Duty /NRMM – Emission Standards (ETC) & -Technology Shift of Priorities
PM
[m
g/k
Wh
]
NOx [g/kWh]1
60
30
42 6
EU V EU IV
03
Engine TechnologyEU VI; NRMM >130 kW Stage 3 B
NRMM EUStage IV
SCR 80 % NRMMStage IIIB(2012)
NRMM EU IIIB
SCR 80 % EU VI
Heavy Duty /NRMM – Emission Standards (ETC) & -Technology Shift of Priorities
PM
[m
g/k
Wh
]
NOx [g/kWh]1
60
30
42 6
EU V EU IV
03
Engine TechnologyEU VI; NRMM >130 kW Stage 3 B
NRMM EUStage IV
SCR 80 % NRMMStage IIIB(2012)
NRMM EU IIIB
EU VI
Heavy Duty /NRMM – Emission Standards (ETC) & -Technology Shift of Priorities
PM
[m
g/k
Wh
]
NOx [g/kWh]1
60
30
42 6
EU V EU IV
EU VI
03
Engine TechnologyEU VI; NRMM >130 kW Stage 3 B
NRMM EUStage IV
NRMM EU IIIB
SCR >92 -95 %
Agenda
Introduction
Challenges to achieve high efficient SCR
SCR Dosing System
Evaporation and Mixing Pipe
Close coupled compact SCR-System
Conclusion
Priorities
PC / LD / MD NEDC
RDE /(NTE)
++
+++
+ ++ + ++ >80
FTP ++ + ++ + ++ >80
US06 ++ + >80
JC08 ++ + ++ + ++ >80
Non-Road
NRMM
NRSC ++ >95
NRTC cold + ++ ++ ++ ++ > 80
NRTC.Warm + ++ + > 95
HD On-Road Steady State + >93
ETC + ++ ++ >93
WHTC cold ++ ++ ++ ++ ++ >70
WHTC warm ++ ++ ++ ++ >80
FTP + + ++ ++ ++ >80
JE05 ++ + ++ ++ ++ >80
Thermodynamic Challenges
Heat up during cold start
low temperature condition
Start of AdBlue Injection
AdBlue-Decomposition
NH3/ NOx Uniformity
SCR “Light-Off”
SCR Conversion
Limitation SCR Kinetic
Limitation of NH3/ NOx
Limitation NH3 storage
Challenges and demands for SCR- Emission control technologies across various applications
Duty Cycle goals with lowestbsf and lowest coolingrequirements
Fundamental Steps for AdBlue Decompositionand Technology for System Optimization
1. Step: evaporation of Water: {(NH2)2CO •7H2O}fl {(NH2)2CO}fl + 7 H2O
2. Step: thermolysis of Urea: {(NH2)2CO}fl HNCO + NH3
3. Step: hydrolysis of isocyanic acid: HNCO + H2O CO2 + NH3
steps from AdBlue towards Ammonia:
Adblue® droplet penetration on surface evaporation & thermolysis1. + 2. reaction steps
AdBlue droplet interaction on surface
Emitec-Technology for Optimization:
� Optimize Hydrolysis: Usage of Hydrolysis Catalyst / Mixer
� Optimize NH3 – Distribution: Optimization of Mixing pipe and mixing design
0
10
20
30
40
50
60
70
80
90
100
0 100 200 300 400
NO
x C
on
ve
rsio
n R
ate
[%
]
Temperature [°C]
NO2 / NO50% / 50%
NO2 / NO0% / 100%
TemperatureRange at low
load operation
0
1
2
3
4
5
6
Engine Out behind DOC behind SCRN
O,
NO
2[g
/kW
h]
NO
NO2
NOx- SCR-Efficiency as Function of NO-NO2-Ratio
Standard SCR- Reaction with NO: 4 NO + O2 + 4 NH3 4 N2 + 6 H2O
“fast“ SCR-Reaction with NO+NO2: 2 NO2 + 2 NO + 4 NH3 4 N2 + 6 H2O
Reaktionen bei der NOX – Reduktion durch SCR:
Emissions during ETC
- 30%
NO2
NO2
NO2
NO
Calculated NOx-Reduction and NH3 Slip as Function of NH3-Uniformity and AdBlue-Dosing Rate
70
75
80
85
90
95
100
0,88 0,9 0,92 0,94 0,96 0,98 1
NOx-Reduction
NH3-Uniformity
Alpha = 1.00
Alpha = 0.95
Alpha = 0.90
Alpha = 0.80
0
10
20
30
40
50
60
0,88 0,9 0,92 0,94 0,96 0,98
NH3- Slip
NH3-Uniformity
Calculated NOx-Reduction and NH3 Slip as Function of NH3-Uniformity and AdBlue-Dosing Rate
70
75
80
85
90
95
100
0,88 0,9 0,92 0,94 0,96 0,98 1
NOx-Reduction
NH3-Uniformity
Alpha = 1.00
Alpha = 0.95
Alpha = 0.90
Alpha = 0.80
80
85
90
95
100
0 5 10 15 20 25 30
NH3-Slip
NO
x-C
on
vers
ion
[%
]
short tube
long tube
NOx = 200ppm
DeNOx Performance as Function of NH3- Uniformity
SCR
AdBlue
DOC
SCRAdBlue
DOCshort tube
long tube
Short tube
Long tube
Influence of System Design on NH3-Uniformity and DeNOx- Performance
70
75
80
85
90
95
100
105
0 10 20 30 40 50 60 70 80 90 100 110 120
NO
x-C
on
vers
ion
[%
]
NH3-slip [ppm]
T= 410°C
NOx = 350 ppm
SV.SCR = 58.000 1/hrS-tube
straight tube
S-tube
straight tube
Influence of Dosing Frequency on the NOx Conversion Rate
NOx tailpipe +- 14%Delta_peak = 80 ppm
NOx tailpipe +- < 1%Delta_peak = 5 ppm
n = 1800 min-1
TQ = 700 NmNOxUP = 450 ppmAlpha NOx = 0,9
time [s]
0 5 10 15 20
NO
x d
ow
n S
CR
[ppm
]
260
280
300
320
340
360
380
400
High dosing frequency Low dosing frequency
Actu
al_
Dosin
g_R
ate
[m
l/h
0
400
800
Time
NO
x T
ail
pip
e
Do
sin
g R
ate
High efficiency SCR system has to have a continuous flow of Adblue At high conversion rate targets is a high dosing frequency mandatory
Agenda
Introduction
Challenges to achieve high efficient SCR
SCR Dosing System
Evaporation and Mixing Pipe
Close coupled compact SCR-System
Conclusion
Emitec SCR-Dosing System Gen III
In Tank SCR-DosingsystemGen III
Customized Tank for the application
Emitec Gen III System DescriptionAll in One Integration
Suction lance
Temperature sensor
Urea filter
Level sensor
Tank heater
Heated suction line
External DCU
Installation cost:
Electrical harness
Fixing devices
Lines connections
Quality sensor
Ringfilter
Electrical ConnectorConnector to
Injector
Emitec Dosing System Gen III; Outside View
Pump
PTC Heater
Level-/Quality Sensor
Pressure Sensor
Pressure ControlValve
Electronic
Emitec Dosing System Gen III; Inside View
Large Engine Airless Dosing System
LE-DCU
Injectors(Airless, Watercooled)
. . . .
Dosing Pumpswith Urea Pumphead (60 ltr/h and 150 ltr/h))
Large EngineDosing Control Unit
Manifoldwith SAE-Connectors
Agenda
Introduction
Challenges to achieve high efficient SCR
SCR Dosing System
Evaporation and Mixing Pipe
Close coupled compact SCR-System
Conclusion
NOx -Efficiency with Optimized Airless Dosing Layout Evaporation and Mixing Pipe
Mo
tor
Dre
hm
om
en
te
ng
ine
to
rqu
e
Motor Drehzahlengine speed
low temperature area
• fast start of dosing
• excellent evaporation of droplets
• low risk for depositions
+ static mixer
+ Hydrolysis Catalyst
Thermal Challenges for AdBlue Injection within Engine Map
Engine Speed
To
rqu
e
NOx -Efficiency with Optimized Airless Dosing Layout Sweep Test
86
88
90
92
94
96
98
100
0,85 0,9 0,95 1 1,05
NO
xE
ffic
ien
cy
Alpha (-)
Test conditions:� constant speed / torque• constant temperature and massflow and exhaust gas condition• exhaust gas 714 kg/h, T = 420 °C, NOx = 543 ppm; NO2/NOx = 0,27theoretical AdBlue® demand for (alpha = 1) = 1100 ml / h
� setup with Fe-Zeolithe catalyst [Ø242 x (110 + 110)] ���� 10,1 ltr� dosing rate 1000 ml / h ���� 1200 ml/h (alpha = 0,9 ... 1,1)
Agenda
Introduction
Challenges to achieve high efficient SCR
SCR Dosing System
Evaporation and Mixing Pipe
Close coupled compact SCR-System
Conclusion
Compact SCR System for Heavy Duty and Non Road Mobile Machineries
DOC
LS/PE-Metalit®
Compact SCR System for Heavy Duty and Non Road Mobile Machineries
AdBlue-Injector
DOC
LS/PE-Metalit®
- Robust design based on mass production
- gasoline injector- Spray charactristic optimized
Reductant Delivery Unit (Urea Injector)
Water Cooling for robustOff Road demands
Compact SCR System for Heavy Duty and Non Road Mobile Machineries
AdBlue-Injector
Mixing Element /Hydrolysis CatalystDOC
LS/PE-Metalit®
Comparison of a Mixer / Hydrolysis Catalyst regardingDeposits at Low Temperature AdBlue Injection
Variant 1 withMixing Element
Variant 2 withHydrolysis Catalyst
N= 1200 1/min; Md = 215 Nm
Exhaust Mass: 326 kg/h; T = 230°CAdBlue-Dosage = 560 g/h, α = 0.8
Compact SCR System for Heavy Duty and Non Road Mobile Machineries
AdBlue-Injector
Mixing Element /Hydrolysis CatalystDOC
LS/PE-Metalit®
SCR- Catalyst
LS-Metalit®
Compact SCR System for Heavy Duty and Non Road Mobile Machineries, Demonstrator
close coupledDOC + 1. stage SCR
2.Stage SCR
SCR only System Layout
Engine
DOC(2,2 ltr) static mixer
SCR 1(6,5 ltr)
SCR 2(4,0 ltr)
close coupled
NOx T NOxT
NOx
1. Stage 2. Stage
0 Total velocity [m/s] 10
Flow / NH3 Distribution @ Close Coupled SCR Catalyst
UI = 0,96
m= 550 kg/hT = 430 °Cm.AdBlue = 1,29 kg/h(12 shots/sec)
AdBlue Flow at constant Exhaust Flow
Accumulated NOx Emissions pre and post 1.Stageat Alpha = 1 during NRTC
time [sec]
0 200 400 600 800 1000 1200 1400
Accu
mula
ted A
dB
lue [
g]
0
100
200
300
Accum
ula
ted N
Ox [
g]
0
5
Accum
ula
ted
NO
x [
g]
0
30
60
90
NOx after 1. Stage
SC
AL
E
NOx after 1. Stage
Accumulated NOx Emissions at Alpha = 1 during NRTC
0 200 400 600 800 1000 1200 1400
0
100
200
300
0
5
0.0
30.0
60.0
90.0
time [s]
Acu
mu
late
dN
Ox [
g]
Acu
mu
late
dN
Ox [
g]
Acu
mu
late
dA
dB
lue [
g]
AdBlue-Mass
NOx Tailpipe
NOx after 1. Stage
NOx engine out
Accumulated NOx Emissionen after 1st and 2nd SCR Stage during NRTC Test
1. SCR Stage
2.SCR Stage
post SCR 2
94,6 %
91,1 %
0 200 400 600 800 1000 1200 1400
0
30
60
90
0
3
time [s]
Acu
mu
late
dN
Ox [
g]
Acu
mu
late
dN
Ox [
g]
Total NOx Reduction and NH3 Slip during NRTC Test
TailpipeNH3 concentration(no NH3 slip catalyst)
SCRa
94,6 %
time [s]
0 200 400 600 800 1000 1200 1400
0
30
60
90
0
100
NH
3[p
pm
]A
cu
mu
late
dN
ox
[g]
Agenda
Introduction
Challenges to achieve high efficient SCR
SCR Dosing System
Evaporation and Mixing Pipe
Close coupled compact SCR-System
Conclusion
η.NH3 > 94 %High Efficient SCRTechnolgyη.NH3 > 94 %
Advanced DOC Technology
Robust AdBlue-Injection
Excellent Decompostion of Reduction Agent
Perfect Mixing of NH3 with Exhaust Gas
OptimizedNH3 Slip Catalyst
UI.NH3 > 0,98
Minimum HNCO concentration
SCR Catalyst Technoloy
η.HC > 90 %NO2/NOx < 0,5
10110100 10110100
10110100 01010101
01001010 01001010
01010100 01001010
AdvancedDosing Strategy
High Performance SCR Technology with Ultra-Low-NOxEmissions for Future Regulations
Emitec Gesellschaft für Emissionstechnologie mbH
Klaus Müller-HaasOswald Holz
CTI, Emission Reduction for Off Highway Applications26.-27.9 2012, Lindau am Bodensee (Germany)