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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)