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Update on 2007 Diesel Particulate Update on 2007 Diesel Particulate Measurement Research Measurement Research

(Project E(Project E--66)66)

Imad A. Khalek, Southwest Research InstituteImad A. Khalek, Southwest Research InstituteShirish Shimpi, Cummins Inc.Shirish Shimpi, Cummins Inc.

Presented byPresented by

Shirish ShimpiShirish Shimpi

1111thth DEER Conference, August 21DEER Conference, August 21--25, 200525, 2005

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AcknowledgmentsAcknowledgments

The EThe E--66 Project is Sponsored by:66 Project is Sponsored by:

Coordinating Research Council (CRC)Coordinating Research Council (CRC)Department of Energy/National Renewable Department of Energy/National Renewable Energy Laboratory (DOE/NREL)Energy Laboratory (DOE/NREL)Environmental Protection Agency (EPA)Environmental Protection Agency (EPA)Engine Manufacturers Association (EMA)Engine Manufacturers Association (EMA)California Air Resources Board (CARB)California Air Resources Board (CARB)

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Project EProject E--66 Panel Members66 Panel MembersMr. Adewale Aoshinuga Aoshinuga, SCAQMDMr. Brent Bailey, CRCDr. Ewa Bardasz, LubrizolDr. Nick Barsic, John DeereMr. Mike Bogdanoff, SCAQMDDr. Steve Cadle, General MotorsDr. Bruce Cantrell, EPAMr. King Eng, Shell Global Solution (U.S.), Inc.Mr. Tim French, EMAMr. Rob Graze, CaterpillarDr. Doug Lawson, NRELMr. Hector Maldonado, CARBDr. Matti Maricq, FordDr. Mani Natarajan, Marathon Ashland Petroleum Co.Dr. Shirish Shimpi, Cummins, Inc.Mr. Matt Spears, EPAMr. Joe Sucheki, EMAMr. Bill Trestrail, International Truck and Engine Corp.Mr. Ken Wright, ConocoPhillips, Inc.

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Project EProject E--66 Main Objectives 66 Main Objectives Phase 1Phase 1

To develop a reference filter method for PM measurement that To develop a reference filter method for PM measurement that accounts foraccounts for or or minimizesminimizes positive and negative measurement artifact associated with gas positive and negative measurement artifact associated with gas phase phase adsorption or desorption from filter media during PM samplingadsorption or desorption from filter media during PM sampling

To evaluate alternative real time PM sampling methods that correTo evaluate alternative real time PM sampling methods that correlate well with late well with the newly developed filter method. Particle instruments includedthe newly developed filter method. Particle instruments included the SMPS, the SMPS, EEPS, QCM, and DMMEEPS, QCM, and DMM--230.230.

Phase 2Phase 2

To investigate the influence of dilution conditions on particle To investigate the influence of dilution conditions on particle mass measurement mass measurement using the 2007 CVS sampling technique using the 2007 CVS sampling technique

Phase 3Phase 3

To correlate PM measured using CVS with PM measured using partiTo correlate PM measured using CVS with PM measured using partial flow al flow sampling systemssampling systems

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IntroductionIntroductionWork under Phase 1 of Project EWork under Phase 1 of Project E--66 was already 66 was already completed. The findings were presented at the 2004 DEER completed. The findings were presented at the 2004 DEER Conference, and at the 2005 CRC Workshop. The final Conference, and at the 2005 CRC Workshop. The final report on Phase 1 was submitted to CRC and can be report on Phase 1 was submitted to CRC and can be downloaded from CRC Website at: downloaded from CRC Website at: http://www.crcao.com/reports/recentstudies2005/Final%20Rhttp://www.crcao.com/reports/recentstudies2005/Final%20Rportport--1041510415--Project%20EProject%20E--6666--Phase%201Phase%201----R3.pdfR3.pdf

This presentation focuses on Phase 2 of Project EThis presentation focuses on Phase 2 of Project E--66, 66, including the influence of dilution conditions on particle including the influence of dilution conditions on particle mass measurementmass measurement

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OutlineOutline

Experimental SetupExperimental SetupInfluence of Dilution Parameters on Influence of Dilution Parameters on Particle Measurement:Particle Measurement:

CVS Primary Dilution RatioCVS Primary Dilution RatioCVS Primary Dilution Residence TimeCVS Primary Dilution Residence TimeSecondary Dilution RatioSecondary Dilution RatioSecondary Dilution Residence Time Secondary Dilution Residence Time

ConclusionsConclusions

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Diesel Engine, DPF, Oil, and Diesel Engine, DPF, Oil, and Fuel for EFuel for E--6666

Engine: Engine: 1998 DDC Series 60, 12.7 liter, heavy1998 DDC Series 60, 12.7 liter, heavy--duty onduty on--highway diesel enginehighway diesel engine

Diesel Particulate Filter (DPF)Diesel Particulate Filter (DPF)Johnson Matthey CRT Johnson Matthey CRT

OilOilExperimental oilExperimental oil-- Lubrizol 2007 projected specificationLubrizol 2007 projected specification

FuelFuelUltra low sulfur diesel (ULSD) fuel, 7ppm sulfur Ultra low sulfur diesel (ULSD) fuel, 7ppm sulfur contentcontent-- Sinclair 2007 projected specificationSinclair 2007 projected specification

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Experimental SetupExperimental Setup

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Real Time Particle InstrumentsReal Time Particle Instruments

Scanning Mobility Particle Sizer Scanning Mobility Particle Sizer (SMPS, TSI)(SMPS, TSI)Engine Exhaust Particle Sizer (EEPS, Engine Exhaust Particle Sizer (EEPS, TSI)TSI)Quartz Crystal Micro Balance (QCM, Quartz Crystal Micro Balance (QCM, Sensors)Sensors)Dekati Mass Monitor (DMMDekati Mass Monitor (DMM--230, 230, Dekati)Dekati)

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Improved Correlation Between FilterImproved Correlation Between Filter--Based and InstrumentBased and Instrument--Based PM Based PM

(CRT(CRT--DPF with Bypass)DPF with Bypass)

It is important to note that this correlation does not apply to measurement downstream of CRT-DPF without bypass, where the dilute PM concentration is very low and dominated by volatile material

y = 0.8545xR2 = 0.9892

y = 0.8927xR2 = 0.9622

y = 1.2032xR2 = 0.9522

0

20

40

60

80

100

120

0 20 40 60 80 100 120Filter-Based Dilute PM Concentration, µg/m³

Inst

rum

ent-B

ased

Dilu

te P

M C

once

ntra

tion,

µg/

m³

EEPS DMM-230 SMPS Linear (EEPS) Linear (DMM-230) Linear (SMPS)

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Basis for Using Real Time Basis for Using Real Time InstrumentsInstruments

Real time instruments for dilute exhaust particle Real time instruments for dilute exhaust particle measurement were used for this study because measurement were used for this study because they demonstrated a good correlation with the they demonstrated a good correlation with the filter basedfilter based--method, during Phase 1 of Project Emethod, during Phase 1 of Project E--66, using DPF with bypass 66, using DPF with bypass For this work, real time instruments were used For this work, real time instruments were used instead of filters to:instead of filters to:

Investigate a wide variety of dilution conditions in a Investigate a wide variety of dilution conditions in a short period of time because filters require long short period of time because filters require long sampling time for adequate loadingsampling time for adequate loadingTo allow, in a followTo allow, in a follow--up work, selected verification of up work, selected verification of the results using filters instead of real time the results using filters instead of real time instrumentsinstruments

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Higher CVS Primary Dilution Ratio Leads to a Higher CVS Primary Dilution Ratio Leads to a Higher PM Emission (Rated Power)Higher PM Emission (Rated Power)

(100 (100 μμg/m3 is equivalent to 0.0005 g/hpg/m3 is equivalent to 0.0005 g/hp--hr, 5 % of the 2007 PM Standard)hr, 5 % of the 2007 PM Standard)

1

10

100

1000

10000

0 2 4 6 8 10

CVS Primary Dilution Ratio

Exh

aust

Par

ticle

Mas

s C

once

ntra

tion,

µg/

m³

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DMM EEPS SMPS Teflo Filter QCM

Rated Speed, 100 % LoadCVS Flow = 1000 SCFMSecondary Dilution Ratio of 1.5

Note that the concentration is reported after being multiplied by the total dilution ratio. The measured dilute concentration was very low for reliable particle mass measurement by EEPS, SMPS, and DMM-230

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Higher CVS Primary Dilution Ratio Leads to a Higher CVS Primary Dilution Ratio Leads to a Higher PM Emission (Rated Power)Higher PM Emission (Rated Power)

(100 (100 μμg/m3 is equivalent to 0.0005 g/hpg/m3 is equivalent to 0.0005 g/hp--hr, 5 % of the 2007 PM Standard)hr, 5 % of the 2007 PM Standard)

1

10

100

1000

10000

0 1 2 3 4 5 6 7 8 9 10

CVS Primary Dilution Ratio

Exh

aust

Par

ticle

Con

cent

ratio

n, µ

g/m

³

DMM SMPS EEPS QCM

Rated Speed, 100 % LoadCVS Flow =2000 SCFMSecondary Dilution Ratio= 1.5

Note that the concentration is reported after being multiplied by the total dilution ratio. The measured dilute concentration was very low for reliable particle mass measurement by EEPS, SMPS, and DMM-230

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Higher CVS Primary Dilution Ratio Leads to a Higher CVS Primary Dilution Ratio Leads to a Higher PM Emission (Peak Torque)Higher PM Emission (Peak Torque)

(100 (100 μμg/m3 is equivalent to 0.0003 g/hpg/m3 is equivalent to 0.0003 g/hp--hr, 3 % of the 2007 PM Standard)hr, 3 % of the 2007 PM Standard)

1

10

100

1000

10000

0 1 2 3 4 5 6 7 8 9CVS Primary Dilution Ratio

Exh

aust

Par

ticle

Con

cent

ratio

n, µ

g/m

³

DMM SMPS EEPS QCM

Peak Torque Speed, 100 % LoadCVS Flow = 2000 SCFMSecondary Dilution Ratio = 1.5

Note that the concentration is reported after being multiplied by the total dilution ratio. The measured dilute concentration was very low for reliable particle mass measurement by EEPS, SMPS, and DMM-230

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Calculation Revealed that Higher CVS Primary Dilution Ratio Calculation Revealed that Higher CVS Primary Dilution Ratio Leads to a Higher Saturation Pressure Ratio in the Dilution RatiLeads to a Higher Saturation Pressure Ratio in the Dilution Ratio o Range Below 40, Depending on Initial Exhaust Temperature Range Below 40, Depending on Initial Exhaust Temperature

Saturation pressure ratio is the ratio of partial pressure over vapor pressure, where higher ratios favor particle nucleation and growth.

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

1 10 100

Dilution Ratio

Satu

ratio

n Pr

essu

re R

atio

for C

16

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Satu

ratio

n Pr

essu

re R

atio

for C

25

C16-Initital Temp 420 C C16-Initial Temp. 320 C C16-Initial Temp. 220 CC25-Initial Temp. 420 C C25-Initial Temp. 320 C C25-Initial Temp. 220 C

Saturation Pressure Ratio (SPR) first increases with the increase in dilution ratio then decreases. The maximum SPR reaches higher values and occurs at lower dilution ratio at lower initial exhaust temperature

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Longer Residence Time Leads to an Increase in Longer Residence Time Leads to an Increase in Particle Mass Emission (Rated Speed, 100 % Load)Particle Mass Emission (Rated Speed, 100 % Load)

(100 (100 μμg/m3 is equivalent to 0.0005 g/hpg/m3 is equivalent to 0.0005 g/hp--hr, 5 % of the 2007 PM Standard)hr, 5 % of the 2007 PM Standard)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 2 4 6 8 10 12 14 16 18 20

Secondary Dilution Residence Time, sec

Par

ticle

Mas

s C

once

ntra

tion,

µg/

m³

Secondary Dilution Ratio of 1.6 Secondary Dilution Ratio of 4.6

SMPS

Region of Significant Particle Growth

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Longer Residence Time Leads to an Increase in Longer Residence Time Leads to an Increase in Particle Mass Emission (Rated Speed, 100 % Load)Particle Mass Emission (Rated Speed, 100 % Load)

(100 (100 μμg/m3 is equivalent to 0.0005 g/hpg/m3 is equivalent to 0.0005 g/hp--hr, 5 % of the 2007 PM Standard)hr, 5 % of the 2007 PM Standard)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 5 10 15 20 25 30 35

Secondary Dilution Residence Time, sec

Exha

ust P

artic

le C

once

ntra

ion,

µg/

m³

Secondary Dilution Ratio of 4.5 Secondary Dilution Ratio of 1.6

DMM-230

Region of Significant Particle Growth

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Longer Residence Time Lead to an Increase in Particle Longer Residence Time Lead to an Increase in Particle Mass Emission (Rated Speed, 100 % Load)Mass Emission (Rated Speed, 100 % Load)

(100 (100 μμg/m3 is equivalent to 0.0005 g/hpg/m3 is equivalent to 0.0005 g/hp--hr, 5 % of the 2007 PM Standard)hr, 5 % of the 2007 PM Standard)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 5 10 15 20 25 30 35

Secondary Dilution Residence Time, sec

Part

icle

Mas

s C

ocen

trat

ion,

µg/

m³

Secondary Dilution Ratio of 1.6 Secondary Dilution Ratio of 4.6

QCM

Region of Significant Particle Growth

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Longer Residence Time Lead to a Significant Increase Longer Residence Time Lead to a Significant Increase in Particle Mass Emission (Rated Speed, 100 % Load)in Particle Mass Emission (Rated Speed, 100 % Load)(100 (100 μμg/m3 is equivalent to 0.0005 g/hpg/m3 is equivalent to 0.0005 g/hp--hr, 5 % of the 2007 PM Standard)hr, 5 % of the 2007 PM Standard)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 5 10 15 20 25 30 35Secondary Dilution Residence Time, sec

Par

ticle

Mas

s C

once

ntra

tion,

µg/

m³

Secondary Dilution Ratio of 1.6 Secondary Dilution Ratio of 4.6

EEPS Region of Significant Particle Growth

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MassMass--Weighted Size Distribution at Different Weighted Size Distribution at Different Secondary Dilution Residence Times Using EEPSSecondary Dilution Residence Times Using EEPS

0

5

10

15

20

25

30

35

40

45

1 10 100 1000Particle Size, nm

Par

ticle

Mas

s co

ncen

tratio

n, µ

g/m

³

0.5 sec 10 sec 18 sec 30 sec

Mass Increase

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Based on Theoretical Derivation, Residence Time Plays Based on Theoretical Derivation, Residence Time Plays More Important Role for Engine With a DPF Compared More Important Role for Engine With a DPF Compared to That Without a DPFto That Without a DPF

0.00E+00

2.00E-01

4.00E-01

6.00E-01

8.00E-01

1.00E+00

1.20E+00

0 0.5 1 1.5 2 2.5 3 3.5Residence Time (sec)

Con

cent

ratio

n R

atio

(N/N

o)

C25H52, 47 °C C16H32, 47 °C H2SO4, 47 °CC25H52, 47 °C-DPF C16H32, 47 °C-DPF H2SO4, 47 °C-DPF

Without DPF

With DPFWhen the soot is captured by the DPF, it takes longer for the gas phase material to be depleted due to the lack of adsorption sites normally provided by soot particles for engines without a DPF.

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ConclusionsConclusionsLonger residence time and higher primary dilution ratio lead to Longer residence time and higher primary dilution ratio lead to an increase an increase in particle mass emissions as indicated by the real time particlin particle mass emissions as indicated by the real time particle instruments. e instruments. It is important to verify this phenomenon with the use of TeflonIt is important to verify this phenomenon with the use of Teflon membrane membrane filter media. filter media.

Residence time seems to play a very important role in affecting Residence time seems to play a very important role in affecting particle particle mass measurement downstream of a DPF, using real time particle mass measurement downstream of a DPF, using real time particle instruments. This is due to the lack of soot that typically servinstruments. This is due to the lack of soot that typically serves as an es as an adsorption site, which contributes to rapid depletion of volatiladsorption site, which contributes to rapid depletion of volatile and semie and semi--volatile material during exhaust dilution and cooling.volatile material during exhaust dilution and cooling.

Even with the longest residence time used in this work, particleEven with the longest residence time used in this work, particle mass mass emissions remained below the EPA 2007 PM standard. It typically emissions remained below the EPA 2007 PM standard. It typically ranged ranged from 3 to 5 percent of the standard at a residence time of 0.5 sfrom 3 to 5 percent of the standard at a residence time of 0.5 second, and it econd, and it increased to about 50 to 75 percent of the 2007 standard at a reincreased to about 50 to 75 percent of the 2007 standard at a residence sidence time of 10 to 15 seconds. time of 10 to 15 seconds.

With the lack of a reference PM standard method for PM instrumenWith the lack of a reference PM standard method for PM instrument t characterization and calibration, real time particle instrumentscharacterization and calibration, real time particle instruments, relying on , relying on assumptions to derive particle mass, may not give accurate PM emassumptions to derive particle mass, may not give accurate PM emission ission results, but good qualitative results, particularly when the mearesults, but good qualitative results, particularly when the measured mass sured mass concentration is below 10 to 20 concentration is below 10 to 20 μμg/m3, and the aerosol is mainly volatile g/m3, and the aerosol is mainly volatile and semiand semi--volatile in nature.volatile in nature.

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Conclusions (Continued)Conclusions (Continued)This work was crucial in pointing out deficiencies in the 2007 PThis work was crucial in pointing out deficiencies in the 2007 PM sampling M sampling protocol relative to the flexibility in allowing different dilutprotocol relative to the flexibility in allowing different dilution ratios and ion ratios and residence times because they lead to different PM mass emissionsresidence times because they lead to different PM mass emissions. This . This was mainly demonstrated by the use of real time particle instrumwas mainly demonstrated by the use of real time particle instruments. It will ents. It will be important to verify that these results also apply when using be important to verify that these results also apply when using Teflon Teflon membrane filter media, the EPA acceptable method in measuring PMmembrane filter media, the EPA acceptable method in measuring PM mass.mass.

This work was also important in pointing out deficiencies in theThis work was also important in pointing out deficiencies in the use of real use of real time particle instruments as mass measuring devices for laborattime particle instruments as mass measuring devices for laboratory or ory or onboard testing. This is due to the lack of a standard method thonboard testing. This is due to the lack of a standard method that verifies at verifies the instruments accuracy in measuring PM mass at different partithe instruments accuracy in measuring PM mass at different particle cle composition and concentration, and the lack of a well defined dicomposition and concentration, and the lack of a well defined dilution lution system ahead of the real time instruments to perform the onboardsystem ahead of the real time instruments to perform the onboardmeasurement.measurement.

This work suggests that more research efforts are needed to undeThis work suggests that more research efforts are needed to understand the rstand the effect of dilution parameters on particle mass emissions using Teffect of dilution parameters on particle mass emissions using Teflon eflon membrane filter media, the current legal method in measuring PM membrane filter media, the current legal method in measuring PM mass. mass. This work also suggests that more research efforts are needed inThis work also suggests that more research efforts are needed in the area the area of developing a reference PM standard protocol for real time parof developing a reference PM standard protocol for real time particle ticle instruments characterization and calibration.instruments characterization and calibration.