On-board Emission Measurement from the World’s Largest Heavy Haulers

Xiaoliang Wang (xiaoliang.wang@dri.edu)Judith C. ChowJohn G. WatsonSteven D. KohlSteven Gronstal

Desert Research InstituteNevada System of Higher Education

Reno, NV, U.S.A.

Presented atA&WMA International Specialty Conference: Leapfrogging

Opportunities for Air Quality Improvement

May 13, 2010

Background: Athabasca Oil Sands Region (AOSR) Reserve: 1.7 trillion barrels of bitumen Production: 1.3 million barrels per day in 2008

Wikipedia: “Athabasca Oil Sands”

Example of Emissions from One AOSR FacilityMine fleet is a major contributor to CO, NOx, and PM in oil sand operations

Sources CO H2S NOx TPM PM10 PM2.5 SO2 VOC

Biomass combustion 3466 0 99 396 313 178 10 446

Flaring 216 5 40 1 1 1 2015 50

Fuel combustion-Cogeneration 574 0 1296 13 13 13 42 19

Fuel combustion-Gasoline light vehicle fleet 203 0 271 17 17 16 2 350

Fuel combustion-Mine mobile fleet 7688 0 9037 213 205 192 12 317

Fuel combustion-Process 23990 0 10289 2582 1540 524 76104 151

Fugitive 0 18 0 0 0 0 0 32859

Process venting 138 6 0 22 13 4 0 7

All 36276 30 21033 3245 2102 929 78185 34199

Mine fleet% 21% 0% 43% 7% 10% 21% 0% 1%

Source: Clearstone Engineering Ltd. Report (2006).

Emission in tons (2003)

Compliance testing do not represent real-world emissions

• To be in compliance with emission standards requires compliance emission rates.

• Source-oriented dispersion modeling and Receptor-oriented source apportionment modeling require real-world emission rates.

• Forest and health effects studies require real-world emission rates and source profiles.

Real-world emissions are needed for all but certification and compliance!

Objectives• Design and test an on-board system that

measures engine emissions under real-world operations.

• Measure real-wold emission factors of criteria and non-criteria air pollutants.

• Obtain VOC and PM2.5 source profiles.

Vehicle: Caterpillar 797B Heavy Hauler

Parameter Specification

Introduction to Service 2002

Nominal Payload Capacity 345 tons

Gross Operating Weight 624 tons

Engine Power 3,370 hp (2,513 kW)

Displacement 117.1 L

Top Speed (Loaded) 42 mph (68 km/h)

Fuel Capacity 1,800 US gal (6,814 liter)

CAT 797 series are among the world’s largest heavy haulers.

Schematics of the On-board Emission Measurement System

Muffler

ElbowConnector Engine

Exhaust

ThermocoupleOmega TJ36-CASS-116U-6-SB

For Exhaust T URG-2000-30ENG

Cyclone7.1 µm Cut

0.8 L/min

ResidenceChamber

PM2.5 impactor

Teflon + Citric acid (mass, babs, element,

isotope, NH3)

Pump

Quartz + K2CO3 (Ions, WSOC, carbohydrates, organic acids, HULIS, SO2)

Quartz + AgNO3 (EC/OC, markers, H2S)

Nuclepore (Lichen study)

5 L/

min

5 L/

min

5 L/

min

5 L/

min

Filtersampler

Flow meter

Box 3: Integrated Sample Module

TSI DustTrak DRX(PM1, PM2.5, PM4,

PM10, PM15)

3 L/

min

0.05

L/m

in

Magee AE51(BC)

0.7

L/m

in

TSI CPC 3007(Concentration 0.01-1 µm)

Grimm 1.108 OPC(Size distribution

0.3-25 µm)

1.2

L/m

in

Box 4: Real Time PM Module

PP S

yste

ms

CO

2 sen

sors

Testo 350(CO, CO2, NO, NO2,

SO2, O2,T, P)

PID 102+(VOC)

0.16

L/m

in

1 L/

min

0.01

L/m

in

Box 2: Real Time Gas Module

Filter

1 liter Canister

(CH4, C2-C12)

1 L/

min

Dilu

ted

1 L/

min

Und

ilute

d1

L/m

in

Bac

kgro

und

DryerHEPA

HEPAFilter

Activated CharcoalAir

Compressor Valve

32 L/min

6.0

L/m

in

Makeup FlowFor Balance

Flowmeter

4.95 L/min26 L/min

2.17 L/min

33.12 L/min

Dilutor

Box1: Sample Conditioning

Box5: Battery

CAT 797B HaulerExhaust Pipe

On-board Emission Measurement System

Sample IntroductionDilutor

ResidenceChamber Dilution Air

Introduction

AirCompressor Valve Flowmeter

CarbonFilter

HEPAFilter

Stream for Undiluted

CO2

Dryer TeflonFilter

Cyclone

Stream toBox 2

Stream toBox 3

Stream toBox 4

Stream to Background

CO2

Testo 350 CO2 Sensors PID Analyzer

Filter PacksCanisterPump for Makeup Flow Flowmeters

Pumps

CPC DRX OPCComputer Deep Cycle Marine Battery

Voltage Regulator

Battery Monitor

Example of Time Series of Emission Concentrations

CO2 (ppm)

0200004000060000

NumberConcentration

(cm-3)01e+72e+73e+74e+7

Black CarbonConcentration

(mg/m3)0

20

40

PM2.5 Concentration(mg/m3)

010203040

CO(ppm)

0200400600

NO(ppm)

02004006008001000

NO2

(ppm)0

20

40

60

Engine Speed(rpm)

500

1000

1500

2000

Dumpingoil sand

Idle Leavingparking lot

Waiting to load

Backingto shovel

Leaving with load

Waitingto load

Leaving with load

Backingto shovel

y = 0.0092x + 6.89R2 = 0.65

0

10

20

30

40

50

60

70

80

90

100

0 2000 4000 6000 8000CO2 (ppm)

NO (p

pm)

y = 16.04x + 2.83R2 = 0.60

0

40

80

120

-1 0 1 2 3 4Black carbon (mg/m3)

CO (p

pm)

y = 1.97x + 0.11R2 = 0.57

-2

0

2

4

6

8

10

12

14

-1 0 1 2 3 4Black carbon (mg/m3)

PM2.

5 (m

g/m

3 )

Sub-activity Engine Conditions and Emission Factors

0

20

40

60

Idle Load to dump Dump to load

Truck Operation

NO

Em

issi

on (g

/kg

fuel

) NO

0.0E+00

4.0E+14

8.0E+14

1.2E+15

1.6E+15

Idle Load to dump Dump to load

Truck Operation

Num

ber E

mis

sion

(#/k

g fu

el)

Particle number

0

0.3

0.6

0.9

1.2

1.5

Idle Load to dump Dump to load

Truck OperationPM

2.5 E

mis

sion

(g/k

g fu

el)

PM2.5 (DRX)

0

300

600

900

1200

1500

1800

Idle Load to dump Dump to load

Truck Operation

Engi

ne S

peed

(rpm

)

Engine speed

0

30

60

90

Idle Load to dump Dump to load

Truck Operation

Eng

ine

Load

(%)

Engine load

0

100

200

300

400

500

600

Idle Load to dump Dump to load

Truck Operation

Exha

ust T

(C)

Exhaust temperature

0

5

10

15

20

25

30

Idle Load to dump Dump to load

Truck Operation

CO

Em

issi

on (g

/kg

fuel

)

CO

0

5

10

15

Idle Load to dump Dump to load

Truck Operation

NO

2 Em

issi

on (g

/kg

fuel

)

NO2

0

0.3

0.6

0.9

1.2

1.5

Idle Load to dump Dump to load

Truck Operation

BC E

mis

sion

(g/k

g fu

el) BC

Comparison of CAT 797B to EPA Tier 1 Standards

Species Emission Factor (g/kg fuel)

EPA Tier 1 (g/kg fuel)

Emission Rate (kg/day)

Emission Rate (ton/year)

Gases

CO2 3147 6 14767 28 5390 10

CH4 1.6 0.6 7.6 2.6 2.8 0.9

CO 8.5 3.8 51.0 39.7 17.6 14.5 6.4

NO 31.0 5.1 145.5 23.7 53.1 8.7

NO2 3.6 1.2 16.8 5.5 6.1 2.0

NOx 34.6 6.0 41.2 162.3 28.3 59.2 10.3

SO2 (5.3 6.3)×10-3 (2.5 2.9) ×10-2 (9.2 1.1) ×10-2

H2S (4.3 6.4) ×10-5 (2.0 3.0) ×10-4 (7.4 1.1) ×10-4

NH3 (7.2 15) ×10-5 (3.4 7.1) ×10-4 (1.2 2.6) ×10-4

NMHC (8.7 3.1) ×10-2 5.8 0.41 0.14 0.15 0.05

PM

Number (2.4 3.0) ×1015 (1.1 1.4) ×1019 (4.0 5.2) ×1021

PM2.5 0.62 0.26 2.4 2.92 1.24 1.07 0.45

BC 0.49 0.11 2.32 0.51 0.85 0.19

Assumed: Fuel consumption rate 5520 L/day; Brake specific fuel consumption (BSFC) 0.223 kg/kW-hr or 0.367 lb/hp-hr.

Alkanes and alkenes ~30-60%, and aromatics ~10% of NMHC

Compound Abundance

Ethylene 0.255 0.046

n-Heptane 0.111 0.128

Propylene 0.100 0.022

Acetylene 0.058 0.022

1-Butene 0.057 0.026

Ethane 0.046 0.037

Toluene 0.036 0.010

n-Decane 0.032 0.018

1-Pentene 0.022 0.007

n-Nonane 0.021 0.016

n-Butane 0.018 0.014

isobutylene 0.017 0.004

Benzene 0.017 0.008

2-Methyl-1-Pentene 0.016 0.006

n-Undecane 0.014 0.005

m/p-Xylene 0.014 0.005

n-Hexane 0.014 0.006

Propane 0.012 0.009

m-Ethyltoluene 0.012 0.006

n-Pentane 0.012 0.005

1-heptene 0.010 0.004

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Alkanes&cycloalkanes

Alkenes Acetylene Aromatics

NMHC Compound Group

Con

cent

ratio

n N

orm

aliz

ed to

Sum

of P

AM

S

Site SSite A

Abundance is normalized to the sum of 55 photochemical assessment monitoring station (PAMS) compounds

Highlighted are the EPA mobile source air toxics (MSATs).

Carbonaceous species account for ~87% of PM2.5

OC27%

EC60%

Elements1%

Soluble ions3%

Unidentified9%

Na+

K+

OC

P

SCl

Ca

Sc

Ti

Fe Cu

Zn

Ga

SrZr Nb Ag Sn

Ba

Au

EC

Ca2+Mg2+

NH4+

PO43-

NO2-

NO3-

SO42-

Mo

Si

K

Sb LaSm

EuUr

0.001

0.01

0.1

1

10

100

Chemical Species

Chem

ical

Abu

ndan

ce (%

)

Site A

Summary

• An on-board system was designed and deployed to measure emissions from CAT 797B mining trucks under real-world operations.

• CAT 797B Emission factors were below the EPA Tier 1 standards for CO, NOx, NMHC and PM.

• Source profiles found abundant alkanes and alkenes in NMHC, and OC and EC in PM2.5.

Acknowledgements

• Sponsor: Wood Buffalo Environmental Association (WBEA).

• Valuable discussions and field testing coordination: Dr. Allan Legge (including project initiation), Drs. Kevin Percy, and Yu-Mei Hsu, Ms. Carna MacEachern, Ms. Simone Balaski, and environmental officers at each company.

Filter packsPM2.5 Impactor

Mass, light transmission,

rare-earth elements, elements, isotopes

Channel 1 (5 L/min)

Citric acid-impregnated

cellulose-fiber filter

NH3 as NH4+

PM2.5 Impactor

Ions (Cl-,NO2-, NO3

-, PO4

=, SO4=, NH4

+,Na+, Mg++, K+, Ca++),

total WSOC, WSOC classesa,Carbohydrates, organic acids,

HULIS

Channel 2 (5 L/min)

Potassium carbonate-

impregnated cellulose-fiber filter

SO2 as SO4=

a Neutral compounds (NC) Mono/dicarboxylic acids (MDA) Polycarboxylic acids (PA)

PM2.5 Impactor

OC, EC, carbon fractions, carbonate,

~130 alkanes, alkenes, PAHs, hopanes, and

steranes

Channel 3 (5 L/min)

Silver nitrate-impregnated

cellulose-fiber filter H2S as S

Teflon-membrane filter

Quartz-fiber filter Quartz-fiber filter

PM2.5 Impactor

Lichen study mass and elemental analysis or

morphological analysis

Channel 4 (5 L/min)

Nuclepore Polycarbonate filter

Filter Analysis Chemical

Analysisa

Nuclepore polycarbonate-membrane filter

Silver nitrate-impregnated cellulose-fiber filter

K2CO3-impregnated cellulose-fiber filter

Citric acid-impregnated cellulose-fiber filter

Quartz-fiber filter

Quartz-fiber filter

Teflon-membrane filter

~1-2 cm2 punch

0.5 cm2 punch

½ filter extracted in 20 ml distilled-deionized water (DDW)

XRF for 51 elementsb

Acid Digestion

ICP-MS for rare-earth elements and isotopesd

OC, EC, carbon fractions, carbonate by thermal/optical carbon

Organic Markers by TD-GC/MSc

Ammonia by AC

½ filter extracted in 10 ml 1:11 hydrogen peroxide: DDW dilution

Whole filter without extraction

Elemental analysis or morphological analysis for lichen studies

Sulfur dioxide by IC

Hydrogen sulfide by XRF as sulfur

½ filter extracted in 10 ml DDW

10 ml for anions and cationse by IC, AC, and AAS, acidified to pH 2 with HCl

1 ml for total WSOC by thermal/optical carbon

Filtration of 5 ml through 0.2 µm PTFE syringe filter

1 ml speciated WSOC separated into three classes: NC, MDA, and PA by HPLC-IEC and UV/Vis detection at 254 nm

1 ml for NC speciation (e.g., carbohydrates) by IC-PAD

1 ml for MDA speciation (e.g., organic acids) by IC with conductivity detector

1 ml for PA speciation (e.g., HULIS) by HPLC–SEC–ELSD–UV/VIS

a Analytical Instruments: AAS: Atomic absorption spectroscopy AC: Automated colorimetry ELSD: Evaporative light scattering

detector HPLC-IEC: High performance liquid

chromatography with an ion exchange column

IC: Ion chromatography IC-PAD: IC with pulsed amperometric

detector ICP-MS: Inductively coupled plasma –

mass spectrometry PTFE: Polytetrafluoroethylene SEC: Size-exclusion chromatography TD-GC/MS: Thermal desorption-gas

chromatography/mass spectrometry UV/VIS: Ultraviolet detector XRF: X-ray fluorescence Observables OC: Organic carbon EC: Elemental carbon HULIS: Humic-like substances MDA: Mono/dicarboxylic acids NC: Neutral/basic compounds PA: Polycarboxylic acids

b Al – U (see Table 7-1) c 124 organic marker species (see

Table 7-1) d Cs, Ba, La, Ce, Pr, Nd, Sm, Eu,

Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Pb204, 205, 206, 207, 208

e Cl-, NO2, NO3-, PO4

=, SO4= (by

IC); NH4+ (by AC); Na+, Mg++, K+,

and Ca++ (by AAS)

BC, EC, babs

BC = 1.39 x EC - 62R2 = 0.96

babs = 15.9 x EC - 1400R2 = 0.83

0

2000

4000

6000

8000

10000

12000

14000

0 100 200 300 400 500 600 700 800 900 1000

EC Concentration (µg/m3)

b abs

(mM

-1)

0

100

200

300

400

500

600

700

800

900

BC

Con

cent

ratio

n (µ

g/m

3 )

babsBC