RETROFIT EMISSION CONTROL RETROFIT EMISSION CONTROL TECHNOLOGIES FOR HEAVY DUTY TECHNOLOGIES FOR HEAVY DUTY

DIESEL ENGINES - THE STATE OF THE DIESEL ENGINES - THE STATE OF THE ARTART

Sougato Chatterjee Johnson Matthey Catalysts

BAQ 2004

Outline

• Diesel Engine Emissions

• PM Control Technologies

• NOx Control Technologies

• Conclusions

Diesel Engine Emission Control

• Diesel engine emissions:– PM (Particle Matter)– NOx (Nitrogen Oxides)– CO (Carbon Monoxide)– HC (Hydrocarbons)

• New engine emissions are being significantly reduced with increasingly tighter emission standards

• However, some of the existing, high-emitting diesel engines will be in use for the next 10 to 25 years

• Using emission control technologies to produce extremely clean new engines as well as to retrofit existing engines is the way to reduce emissions

Schematic of Diesel Particles and Vapor Phase Compounds

Reprinted with Permission from SAE paper no. 940233 C 1994 Society of Automotive Engineers, Inc.Reprinted with Permission from SAE paper no. 940233 C 1994 Society of Automotive Engineers, Inc.

Vapor Phase Vapor Phase HydrocarbonsHydrocarbons

Sulfate (SOSulfate (SO44))

Adsorbed HydrocarbonsAdsorbed Hydrocarbons

Soluble Organic Soluble Organic Fraction (SOF)/Fraction (SOF)/Particle Phase Particle Phase HydrocarbonsHydrocarbons

Solids Solids (SOL)(SOL)

Solid Carbon Spheres (0.01 - Solid Carbon Spheres (0.01 - 0.08 mm diameter) combine to 0.08 mm diameter) combine to make Particle Agglomerates make Particle Agglomerates (0.05 - 1.0 mm diameter with (0.05 - 1.0 mm diameter with Adsorbed HydrocarbonsAdsorbed Hydrocarbons

Adsorbed HydrocarbonsAdsorbed Hydrocarbons

Liquid Condensed Liquid Condensed Hydrocarbon ParticlesHydrocarbon Particles

Sulfate with HydrationSulfate with Hydration

17179701

Outline

• Diesel Engine Emissions

• PM Control Technologies

– DOC technology

– DPF technology

– Fuel Sulfur Effect

– Advanced DPF technology

– Active Regeneration Filter Technology

– Partial Filter technology

• NOx Control Technologies

• Conclusions

Diesel Oxidation Catalyst

Diesel Oxidation Catalysts (DOC)

• Oxidizes CO and HC to CO2 and H2O (desired)

• Oxidizes toxics such as aldehydes

• Oxidizes SO2 to SO3 (undesired)

• Oxidizes Soluble organic fraction (SOF, HCs) adsorbed on Particulates to reduce PM

• CO, HC reduction up to 90%.

• PM reduction up to 50% depending on SOF content of PM; Typically 25% on new engines

Ceramic Catalyst

DOC in a muffler

Particulate Matter Oxidation

CarbonSoot

Catalyst

CarbonSoot

Note: Soluble Fraction,Sulfates and Water are in Vapor form.

DOC - Applications

• Can work with high sulfur fuel (up to 500 ppm)• Benefits from low S fuel (low sulfate make)• Can activate at lower temperature for CO & HC

reductions • Proven low-cost technology• Combined catalyst and muffler to provide sound

attenuation and emission benefit• Easy to retrofit on existing vehicles

– 2 stroke & 4 stroke• No required maintenance• Variety of sizes and shapes for different applications

DOC Performance 500 PPM S Fuel

PM(g/bhp-

hr) Reduction

CO(g/bhp-

hr) Reduction

HC(g/bhp-

hr) Reduction2-Stroke

Baseline 0.44 1.0 0.7

W/ CEM 0.22 50% 0.6 40% 0.4 43%

4-Stroke

Baseline 0.073 1.11 0.115

W/ CEM 0.055 25% 0.35 68% 0.014 88%

Tested at Southwest Research InstituteunderEPA approved FTP transient test cycle

DOC Performance on BEST EURO II Bus500 ppm S Fuel

0

0.5

1

1.5

2

2.5

3

CO HC NOx/10 PM

Em

iss

ion

s (

g/k

m)

Base Engine Emissions

Engine with DOC

27%

Diesel Particulate Filter

Diesel Particulate Filter • Johnson Matthey Continuously Regenerating

Technology (CRT®) Diesel Particulate Filter

CRT® Particulate Filter for >90% PM Removal

• Patented CO/HC/PM Emission Control System combining Oxidation Catalyst & Filter

• Engineered as a totally passive emission control system which requires no supplemental heat

• Uses NO2 produced by a specially formulated catalyst to burn soot collected by the filter at typical operating temperatures of diesel engine exhaust

• Requires the use of Ultra Low Sulfur fuel (< 50 ppm S) for maximum emission reduction and filter regeneration

CRT® Particulate Filter – Operating Principle

Examples of CRT Installations in the US

Mumbai Transit (BEST) Hino Engine Euro II Bus with CRT

Avg. Emissions Test Results- CRT vs. CNG LA MTA Data – Ser 50 Engines - CBD Cycle

0.0

1

2.9

1

0.0

2

0.1

7

0.0

1

3.5

2

0.1

7

0.0

07

12.01

1.5

2

1.1

8

0.0

09

0

1

2

3

4

5

PM CO/10 THC NOx/10

Em

issi

on

(g

/mil

e)

CRT w/ ECD

CRT w/ ECD-1

CNG

Carbonyl Destruction with CRT on Ser 50 under NY Bus Cycle

181

89

17

287

0.83 0.75 1.83 3.4

2551

42

16

2609

0

50

100

150

200

250

300

Formaldehyde Acetaldehyde Acetone Total Carbonyls

Em

issi

on

s (m

g/m

i)

OE w/ Std. Diesel

CRT w/ ULSD

CNG

Fuel Sulfur Effect on Diesel Particulate Filter

Impact of Fuel Sulfur• Impact of Fuel Sulfur on CRT Regeneration

• Catalyst can be poisoned by high sulfur in fuel • Lower NO2 generation; Problem in filter regeneration

• Impact of Fuel Sulfur on CRT Particulate Emissions• High SO2 oxidation, so sulfate can increase measured PM • Low PM reduction (40 – 50%) due to high sulfate make

Impact of Fuel S on Emissions350 ppm vs. 15 ppm fuel with CRT under FTP

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

BSHC BSNOx/100 BSCO/10 BSPM

Em

iss

ion

s (

g/b

hp

-hr)

Base Engine with LSD

CRT with LSD

Base Engine with ULSD

CRTwith ULSD

CCRT™ - Advanced Passive Filter System

CCRT™ – An Advanced CRT for Challenging Applications

• CCRT = DOC + Catalyzed Filter

• Advantages of CCRT:– Higher soot burn rate than CRT or CSF

• Install in Challenging Applications– Low temperature applications (200 – 250oC)– Low NOx/PM applications (NOx/PM>15)

• Even at low CSF loadings, we see improved performance with the CCRT

• Successfully demonstrated in field trials in the US, Europe and Asia

Use of NOx Within CCRT System

CCRT Experience on low temperature School BusBoston School Bus with 175 hp 2000 MY CAT 3126 Engine

Daily Pressures on

-1

0

1

2

3

4

5

6

12/3

0

1/30

2/28

3/30

4/30

5/30

6/30

7/30

8/30

9/30

10/3

0

11/3

0

12/3

0

1/30

2/29

3/30

4/30

Date

Bac

K P

ress

ure

(in

Hg

)

Max Pres Avg Max Pres Avg Pres

To

Boston School Bus 00630-Dec-02 14-May-04

Temperature Distribution

0

250

500

750

1000

1250

1500

1750

2000

2250

2500

100

125

150

175

200

210

220

230

240

250

260

270

280

290

300

310

320

330

340

350

Exhaust Bins (C)

Fre

qu

ency

(A

bso

lute

)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Tim

e o

ver

tem

p (

%)

Frequency

%Time Above Temp

To

Boston School Bus 00630-Dec-02 14-May-04

•Cold Exhaust Temperature Profile

•Only 8% of time Temp > 260 C; 40% time @ 200 C

•CCRT operating with stable back pressure for over 17 months

Active Regeneration: Low NOx/PM applications

Active Regeneration with Fuel Injection

Courtesy:

Exhaust back pressure

Temperatures

After catalystBefore catalyst

3 hours

140 mbar

Active Regeneration of CRT with Fuel Injection System

Courtesy:

Partial Filter Systems

Partial Filter Product Development

•Partial filtration = moderate (>50%) PM reduction, but minimize filter plugging

–Some PM is trapped, rest goes through

•Use variety of substrates:–Flow through with notches –Wire mesh –Ceramic foam

•Can use in CRT or CCRT configuration for effective soot burn

•Ideally suited for old, dirty engine retrofit–America, Asia

• Work with ULSD proven; Tests in progress with LSD fuel

Step to filtration activity:

porous layer made of sintered metal fiber fleece

Partial Filter Product Development

Trash Truck in CA with Partial Filter

Clean outlet head on partial filter after operation

Emissions Results for Partial Filter SystemCaterpillar 3126 MY 1998, under US FTP Transient cycle

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

PM*10 CO/10 HC Nox/10

Em

issi

on

s (g

/bh

p-h

r)

Engine Out

Engine + PFT

Outline

• Diesel Engine Emissions

• PM Control Technologies

– Fuel Sulfur Effect

• NOx Control Technologies

– EGRT

– SCRT

• Conclusions

EGRT Development & Applications

EGRT™ System• EGRT™ = EGR + CRT®

• CRT = Continuously Regenerating Technology Diesel Particulate Filter

• EGR = Re-circulation of part of the exhaust gas to engine intake air

• Uses STT patented EGR technology in combination with the CRT particulate filter

• ULSD (< 50 ppm) fuel is required

EGRT System and Throttle Valve

Intake Air In

Cooled Exhaust In

EGRT Retrofit on VTA Transit Bus

Emissions Results for EGRT SystemCummins ISL 330 Engine, FTP Cycle on Engine Dyno

0.16

0.38

0.07

0.43

0.03

0.17 0.19

0.00 0.

05

0.00

0.17 0.20

0.06

0.69

0.10

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

FE/1000 NOx/10 THC CO PM

Em

issi

ons

(g/b

hp-h

r)

Baseline (Engine w/ DOC)

w/ EGRT

w/ EGR & OE DOC (no filter)

Selective Catalytic Reduction (SCR)

SCR and SCRTTM System Schematics

Engine

SCR Oxidation Cat

Removal of NOX

Removal of NH3 slip if requiredRemoves CO and some HC’sand PM SOF

1 to 3 way conversion

Urea

Engine

CRT SCR Oxidation Cat

Removal of HC, CO, PMNONO2

Removal of NOX

Removal of NH3 slip if required

4-way conversion

UreaSCR

SCRTTM System

• SCRT = SCR + CRT• System Components

– CRT system– Urea Injection system– SCR system

Retrofit SCRT System

SCRT Field Trial Bus in UK

London Bus – Millbrook Testing

82%

0%

81% 84% 89% 87%

0%

86% 79%

89% 84%

0%

83% 82% 89%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

100%

Setting 1 Setting 2 Setting 3 Setting 4 Setting 5

Outer London Inner London Combined Outer and inner London

NOx (g/bhp-hr)

Effect of Emission Control Retrofit on Current Engines

0.00

0.02

0.04

0.06

0.08

0.10

0 1 2 3 4 5 6 7 8

Par

ticu

late

Mat

ter

(g/b

hp

-hr)

1

2

Starting point1998 Engine

FEDERAL 2002 Oct.

4 3 CRT®

EGRT

DOC

SCRT®

5

Conclusions

• A multiplicity of catalytic emission control technologies now exists to aid the emissions engineer in achieving virtually zero emission levels from diesel engines

• Johnson Matthey provides a variety of PM and NOx control technologies for retrofit and OE applications– PM Control: DOC, CRT, CCRT, PF

– NOx Control: EGR, SCR and LNT

• DOC is a cost effective solution for use with 500 ppm S fuel

• Improved fuel quality especially ultra low sulfur fuel (< 50 ppm) enables the most advanced control strategies (CRT)

• Some engineering challenges remain for advanced system development, and overcoming infrastructure issues

Contacts:• Sougato Chatterjee • (610) 341-8316

Chatterjee@JMUSA.com

WWW.matthey.com

Johnson Matthey India Pvt. Ltd.Plot No. 12, Sector 3IMT ManesarGurgaon – 122 050Haryana, INDIA+91 124 229 0234