1

Experience with SCR Technology for Diesel Exhaust Emission Control of Trucks in Asia,

Europe and North America

Gary Keefe and Raimund Mueller

Bangkok, February 1, 2001

Motivation for Diesel Engine Emission Control

Human health impact

Photochemical smogAcid rainHuman health impact

Human health impact

Greenhouse gas - climate change

Photochemical smog

EngineEmissions

HC

NOx

PM

CO

CO2

2

Why Reducing Nitrogen Oxides?

NitrogenDioxide(NO2)

from the Exhaust Gas

Ozone forms and is inhaled by persons

Sun effect

NitrogenMonoxide

(NO)

AtomicOxigen (O)

MolecularOxigen(O2)

SCR Reactions with Reducing Agent -Urea

Hydrolysis-Reaction:(NH2) 2CO + H2O 2 NH3 + CO2

SCR-Reaction:

4 NH3 + 4 NO + O2 4 N2 + 6 H2O

8 NH3 + 6 NO2 7 N2 + 12 H2O

3

Applications of SINOx Catalysts and Systems

Power Plant Truck

Greenhouse Fertilizer/CoGen

Incinerator

Marine Propulsion

Railroad Engine

Diesel Car

Stationary Diesel

SINOx®-Catalysts

Future Emission Standards for Commercial Vehicles and Market Requirements

Source: Moser et. al.NOx - g/kWh

0190

200

210

220

230

1 2 3 4 5 6 7

Marketrequirement

Legislativerequirement(NOx)

Trade -off with currenttechnology (EU3/US 98)

BSF

C -

g/kW

h

0

0,1

0,2

0,3

0,4

Part

icul

ates

-g/

kWh 2007

2004/2005

2008

1998/2000EUUS

J

Worldwide exhaust emission standards for HD diesel engines beyond 2000

4

Exhaust Emission Control Motivation: Diesel Trade-Off

NOx-Emissions [g/kWh]

98632100

1074 5

0,04

0,06

0,08

0,1

0,12

0,14

0,16

0,18

PM-E

mis

sion

s [g

/kW

h]

0,02

NOx/PMDPF

EGR &Combustion

SINOx

Engine(PM-opt)

NOx/BE

Spec

ific

Fuel

Con

sum

ptio

n[g

/kW

h]Emissions-Reduction Potential with SINOx System

Increase of engine-out NOx emission due to fuel efficient tuning, for lowPM emission

Improvement of BSFC over EURO 3 engineattainable

Emission data in g/kWh

BSFC0

20

40

60

80

100

120

140

160

180

200

NOx HC PM

Rel

ativ

e Em

issi

on in

%

E

5

9

1,8

0,660,6

0,12

0,1

0,03

0,02

80% NOx-reduction

80% HC-reduction

30% PM-reduction

SINOx Capability EURO 3 EnginePM & BSFC optimized engineOptimized engine w/ SINOx

5

The SINOx® System for Trucks

• Urea Dosing Unit,Urea and Diesel tankintegrated in one unit

• SCR-catalyst integratedin series silencer

• base-metal catalyst• ceramic monolith• cat.volume 30 ltr.• 200 cpsi

• 12 l HD-Diesel engines• 6-cylinder• 400 hp class

diagnosis

SCR-Catalyst

NOx, O2

reducingagent

(NH2) 2CO

purifiedexhaust

N2, H2O

Urea-Dosing Unit

exhaust

operating

data

(NH2) 2COEDC

ECU DCU

engine

Characteristics of SINOx SCR Systems

Active emission control system• integrated solution - „Not just an Add-on“• communication between engine and urea dosing unit via CAN bus• integration into the vehicle infrastructure (pressurized air, electrics)

Resources• Diesel fuel with S < 0,15%• 32,5% solution of urea as reducing agent

• Temperature range of exhaust: gas 200...550°C (without oxidation catalyst)• no or slight increase of exhaust backpressure compared to standard silencer• combination with particulate filter feasible if desired for special applications

Function

6

Urea distribution infrastructure conceptIndustry Committee established with members including oilindustry, vehicle and engine manufacturers ureamanufacturers and Siemens:

Step 1- Refilling urea at truck home yard Step 2 - Refilling urea at main truck stops located

along the major highwaysStep 3 - Refilling urea at the gas stations Urea Pump Station

Urea Charateristics:

• non-hazardous, non-explosive, non-toxic• released as a food-additive• lowest water polluting classification

Reducing Agent Aqueous Urea

Urea - Applications

UREA

Agriculture• fertilizer• feed

Water industry• nutritive substance forthe biologicaltreatment of wastewater

Power industry

• reducing agent for exhaust gas

Chemical Industryraw material for:

• UF-resins• Urethanes• and many others Food processing

• for chewing gum production

Medical and pharmaceutics for the production of:

• barbiturates• diuretics• special injury bandages

Other industriesauxiliaries in:

• chipboard industry• textile industry• coolant lindustry• cosmetics industry

There is no shortageof urea

7

SINOx® System - Field Demonstration

Total mileage: 21 trucks 6.099.000 kmMax. mileage of single vehicles: 524.000 km

(Status: 2000-03-27*)

*) 2nd road test finished 1999-12-31. Some vehicles are operated further for long term testing

Measurements

Investigations:

• on the road (vehicle): NOx-reductionUrea consumptionmechanical durability

• in lab reactor (SCR-catalyst): activity (NOx-reduction) = f (mileage)physico-chemical measurements(surface area, composition, etc.)

• on the test bench (silencer): NOx-reduction at start (ESC, ETC)NOx-reduction at end (ESC, ETC)

8

0

0,004

0,008

0,012

0,016

0,02

PM [g

/kW

h]

total PM soluable insoluable0

0,004

0,008

0,012

0,016

0,02

PM [g

/kW

h]

total PM soluable insoluable

PM and NOx emissions - ESC test w/12 ltr. HDE + SINOx

0

2

4

6

8

10

12

NO

x [g

/kW

h]NOx

Engine out emissions after SINOxEngine out emissions after SINOx

- 81%

PM and NOx Emissions - ETC test w/12 ltr. HDE+ SINOx

0

0,004

0,008

0,012

0,016

0,02

0,024

PM [g

/kW

h]

total PM soluable insoluable0

2

4

6

8

10

12

NO

x [g

/kW

h]

NOx

Engine out emissions after SINOx

0

0,004

0,008

0,012

0,016

0,02

0,024

PM [g

/kW

h]

total PM soluable insoluable

- 86%

9

On-board NOx-measurement on mixed highway

Time in seconds

Highway Section Bamberg RedwitzN

Ox-

Con

cent

ratio

n in

ppm

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 750 1500 2250 3000

NOx conversion: 71.2 %NOx conversion: 71.2 % NOx before Cat.

NOx after Cat.

NOx before Cat.

NOx after Cat.

Results of Measurements

Measurements were done and reported by TÜV Automotive, Germany

1st demonstration program: 0 km 130,000 km remark

NOx reduction on-road: 56% 54% constant within accurarcy

Urea consumption fleet average 4.1 % of diesel fuel consumption

2nd demonstration program: 0 km 272,000 km remark

NOx reduction ESC cycle: 65% 63% constant within accurarcy

NOx reduction ETC cycle: 70% 71% constant within accurarcy

NOx reduction on-road: 74% measured after 212,000 km

Urea consumption fleet average 5.5 % of diesel fuel consumption

10

Catalyst activity during field demonstration

•Catalyst Activity in accordance with predicted deterioration factor (over 500,000 km)•Catalyst total specific surface area and active materials constant over test program• Deposition of phoshate on catalyst surface in upstream face of catalyst

0.6

0.7

0.8

0.9

1

0 100 200 300 400 500 600

Driv ing Performance [1000 km]

NO

x C

on

vers

ion

Per

f. (

rel.)

SINOx® Catalyst

Fuel optimized engine meeting EURO 4/2 with SCR

• Engine modification to EURO III engine for best fuel economy (BSFC)

• NOx & PM Emission below EURO 4/2 in ESC and ETC

Program by VROM, AVL, Deutz, Siemens (Source: AVL, Cartellieri et. al. )

0,0

2,0

4,0

6,0

8,0

10,0

12,0

Baseline Optimized w /SCR EUROIV/1

w/SCR EUROIV/2

NO

x,

PM

* 1

00

in

g/k

Wh

180

185

190

195

200

205

210

215

220

225

BS

FC

in

g/k

Wh

NOx

PM * 100

BSFC

11

US truck SCR investigation & demonstration program

-100%-80%-60%-40%-20%

0%20%40%60%80%

100%

emis

sion

s ch

ange

(%)

NOx HC PM CO CO2

cold US-transient hot US-transient OICA

0,00,10,20,30,40,50,60,70,80,91,0

amm

onia

slip

(ppm

avg

)

NH3

US SCR HD Truck Demonstration Program

12

Applying NOx Sensors

0

400

800

1200

1600

0 1 2 3 4 5

NOx sensor output in MV

NO

x (p

pm)

Linear correlation between chemiluminescent analyzer and NOx sensor

NOx sensors upstream and downstream of catalyst accurate

0

300

600

900

1200

1500

0 60 120 180 240 300 360

time (s)

NO

x (p

pm)

SCR OFFbefore catalyst

after catalyst

On-road SCR emission reduction measured w/ NOx Sensors

0

300

600

900

1200

1500

0 60 120 180 240 300 360time (s)

NO

x (p

pm)

Level highway: 77 %Mountain highway 71 %

Urban traffic: 78 %

Overall average: 73 %

----- before catalyst ---- after catalyst

13

Experience with SCR in Asia

SCR included in Japan Clean Air Program (JCAP) technology assessment - results will be published later this year

Japanese diesel engine and truck manufacturers operate SINOx SCR systems in test cells and trucks

SCR Experience in Japan, Taiwan, South Korea in utilitypower plants, gas turbines and Stationary diesels since the1970s

NOx Reduction in Japanese 13 mode Cycle with Japanese Diesel HD Engine

0

500

1000

1500

2000

2500

3000

1 2 3 4 5 6 7 8 9 10 11 12 130

5

10

15

20

25

30NOx without SINOx: 10.4 g/kWh

NOx with SINOx: 3.0 g/kWh

NH3 ppm

NOx-Reduction: 71 %

NO

x g/

h

NH

3 pp

m

Mode No.

14

Monitoring and Diagnosis

• NOx sensors have been demonstrated as applicable technology.

• Upon commercial availablity and proven long-term durablity NOx sensors

• can be useful tool for:

+ Monitoring Diagnosis Control

• Sensors monitor operation and functionality of system components

• Sensors monitor level and quality/grade of reducing agent

• System control unit collects and interprets sensor data

• System control unit transfers information to engine control unit for further evaluation

SCR Trucks becoming available

Field demonstration has proven:

SCR-systems reduce NOx, HC, PM emissions in test cycles and in real world operation

SCR is a viable technology for trucks

SCR durability in accordance with truck operation

What‘s next:

SCR trucks offered by OEMstarting in 2001 2001

15

Customer‘ s benefits using SINOx

• Savings in emission-staged road-pricing - those will be implemented according to Government decisions in several European Countries 2003

• Meeting NOx limits of the two steps Euro 4/1 & 4/2 with the same technologywith fuel efficient Eu 2 engines, lowest PM by adjusted engine tuning & advanced design

• Insensitive to fuel sulfur - operation with current standard fuel (500 ppm S)Truck operation outside central Europe or US with low grade diesel fuel also possible

• Proven longterm stability and durability (> 500,000 km)

• Catalyst system performance is demonstrated to be constant within measurement accuracy

• Flow-Through system, truck mobility not at risk