EPA-650/2-75-054
May 1975
Environmental Protection Technology Series
PARTICULATE EMISSIONS
FROM PROTOTYPE
CATALYST CARS
^
ui
U.S. Environmental Protection Agency
Office of Research and Development
Washington, D. C. 20460
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EPA-650/2-75-054
PARTICULATE EMISSIONS
FROM PROTOTYPE
CATALYST CARS
by
Dr. Morton Bcltzer
Exxon Research and Engineering Company
Products Research Division
Linden, New Jersey 07036
Contract No. 68-02-1279
ROAP No. 21BCE-02
Program Element No. 1AA002
EPA Project Officer: Dr. Ronald L. Bradow
Chemistry and Physics Laboratory
National Environmental Research Center
Research Triangle Park, N. C. 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
WASHINGTON, D.C. 20460
May 1975
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EPA REVIEW NOTICE
This report has been reviewed by the National Environmental Research
Center - Research Triangle Park, Office of Research and Development.
EPA, and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names or commercial
products constitute endorsement or recommendation for use.
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environ-
mental Protection Agency, have been grouped into series. These broad
categories were established to facilitate further development and applica-
tion of environmental technology. Elimination of traditional grouping was
consciously planned to foster technology transfer and maximum interface
in related fields. These series are:
1. ENVIRONMENTAL HEALTH EFFECTS RESEARCH
2. ENVIRONMENTAL PROTECTION TECHNOLOGY
3. ECOLOGICAL RESEARCH
4. ENVIRONMENTAL MONITORING
5. SOCIOECONOM1C ENVIRONMENTAL STUDIES
6. SCIENTIFIC AND TECHNICAL ASSESSMENT REPORTS
9. MISCELLANEOUS
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to
develop and demonstrate instrumentation, equipment and methodology
to repair or prevent environmental degradation from point and non-
point sources of pollution. This work provides the new or improved
technology required for the control and treatment of pollution sources
to meet environmental quality standards.
This document is available to the public for sale through the National
Technical Information Service, Springfield, Virginia 22161.
Publication No. EPA-650/2-75-054
11
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TABLE OF CONTENTS
Page No.
Summary 1
I. Introduction 4
II. Technical Background 7
II. 1 Automotive Particulate Emissions 7 .
II.2 Exhaust Particulate Sampling System 7
II.2.1 Sampling System Components 7
II.2.1.1 Diluent Air Preparation System 9
II.2.1.2 Flow Development Tunne 11
II. 2.1.3 Exhaust Injection System 11
II.2.1.A Isokinetic Probe 11
II. 2.1.5 Particulate Collecting Stage 13
II.2.2 System Performance 13
II.2.2.1 Rapid Mixing of Exhaust and Diluent
Air 13
II.2.2.2 Development of Uniform Flow in the
Flow Development Tunnel 14
II.2.2.3 Tunnel Sampling Losses 15
II.2.2.4 Equivalent Emission Rates with
Parallel Filters 16
II.2.2.5 Temperature Maintenance at the
Particulate Collection State 16
II.2.2.6 Capabilities for Studying Effect of
Temperature on Particulate Collection . 21
III. Experimental 24
III.l Test Vehicles 24
III.1.1 Vehicle Conditioning Procedures 24
III. 1.2 Catalyst Conditioning Procedures 25
III.2 Selection of Fuels , 26
III.2.1 The Additive Package 26
III.2.2 Fuel Specifications 27
III. 3 Catalysts 27
III.4 Test Procedure 29
III.4.1 Gaseous Emissions 29
III.4.2 Particulate Sampling Procedure 30
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- ii -
TABLE OF CONTENTS (Cont'd.)
Page No.
IV. Results and Discussion 33
IV.1 Sulfur Compounds in Exhaust Emissions 33
IV. 1.1 S02 in Auto Exhaust 33
IV.1.2 Dependence of Total Particulate Emission
Rates on Fuel Sulfur Content 33
IV. 1.3 Sulfate Emission Rates 39
IV.1.4 Exhaust Sulfur Material Balance 46
IV.1.4.1 Sulfur Material Balance with Mono-
lithic Oxidation Catalysts 46
IV.1.4.2 Sulfur Material Balance with
Palletized Oxidation Catalysts 56
IV.1.4.3 Sulfur Material Balance with NO
Reduction Catalysts x. . . . 57
IV.1.5 Sulfate Storage on a Pallatized Catalyst System . 58
IV. 1.6 Bound Water in Exhaust Particulate 61
IV.1.7 Morphology of Automotive Sulfate Particulate. . . 63
IV.1.8 Non-Sulfate Sulfur Exhaust Particulate 65
IV.2 Exhaust Metal Particulate Emission Rates 67
IV.2.1 Metal Oxide Emissions Under 1975 FTP Conditions . 67
IV.2.2 Metal Oxide Emissions Under Cruise Conditions,
Relation to Sulfate Emissions 69
IV.2.3 Emission Rates of Specific Metals 69
IV.2.3.1 Emission Rates of Platinum 76
IV. 2. 3.2 Emission Rates of Aluminum 76
IV. 2.3.3 Emission Rates of Lead 76
IV.2.3.4 Emission Rates of Iron 82
IV. 2.3.5 Emission Rates of Nickel 84
IV.2.3.6 Emission Rates of Copper 89
IV. 2.3. 7 Emission Rates of Zinc 89
IV.2.3.8 Emission Rates of Calcium 89
IV.2.3.9 Emission Rates of Chromium 89
IV.2.4 Metal Oxide Emission Rates Following Sulfate
Storage Conditioning. .............. 93
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- iii -
TABLE OF CONTENTS (Cont'd.)
Page No.
IV. 3 Organic Exhaust Particulate Emissions 94
IV.3.1 Carbon Content of Exhaust Particulate 94
IV.3.2 Organic Nitrogenous Particulate 98
IV.4 Size Distribution of Exhaust Particulate 100
IV.4.1 Particle Size Distribution, Base Case Vehicle . 100
IV.4.2 Particle Size Distribution, Oxidation
Catalyst-Equipped Vehicle 100
IV.4.3 Particle Size Distribution, NO Reduction
Catalyst Equipped Vehicle . . ? 110
IV.4.4 Particle Size Distribution After Sulfate
Storage 110
V. References 115
Appendix A - Analytical Methods
A.I Analytical Determination of Sulfate 117
A. 1.1 Reagents 117
A.1.2 Titration Apparatus 117
A. 1.3 Standardization of BaCClO^ Solution 117
A. 1.4 Detailed Titration Procedure 118
A.1.4.1 Effect of Nitric Acid on Measurement
of Sulfate 119
A.1.4.2 Precautions About Titration Procedure. . . 119
A.1.5 Sulfate Determinations on Glass Fiber Filters
Spiked With Known Quantities of H2SO^ 120
A.1.6 Comparison of Titrimetric and Gravimetric
Procedures on Filters from Vehicle Tests 121.
A. 2 Sulfur Dioxide Determination . 123
A. 3 Carbon, Hydrogen, and Nitrogen Determinations 127
A.4 Characterization of Specific Compounds in Automotive
Exhaust Particulate 130
A. 4.1 Bound Water 130
A.4.2 Organic Nitrogen Compounds 130
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- iv -
TABLE OF CONTENTS (Cont'd.)
Page No.
A.4.2.1 Nitrogenous Particulate. 130
A.4.2.2 Organic Nitrogen Compounds 131
A.A.2.3 Compounds Containing Nitrogen and
Oxygen Bonded Together 131
A.A.2.4 Aliphatic and Aromatic Nitro Compounds . . 134
A.A.2.5 Nitrate, Nitrites, Nitroamines, and
Nitrosamines 134
A.A.2.6 Nitriles 134
A.4.3 Organic Sulfur Compounds 135
A.4.3.1 Organically Bound Di- and Tetravalent
Sulfur 135
A.4.3.2 Alkyl and Aromatic Sulfonic Acids 135
A.5 Determination of Metallic Components of Exhaust
Particulate 137
A.S.I Emission Spectroscopy 137
A.5.1.1 Preparation of Calibration Standards . . . 137
A.5.1.2 Assessment of Interaction Effects on
Metal Determinations 149
A.5.1.3 Effect of Presence of Chromium on
Platinum Determination 150
A.5.1.4 Calibrations tor High Levels of Iron,
Zinc, and Lead 150
A.5.2 Platinum Analysis by X-ray Fluorescence 150
Appendix B - Modified Anderson Impactor 159
Appendix C - Exhaust Splitter 162
Appendix D - Basis of Selection of the Sulfur and Nitrogen
Containing Organic Compounds Which Might Appear in an Auto
Exhaust 165
Appendix E - Raw Data 169
E.I - List of Raw Data Tables. ifiQ
E.2 - Precision of Total Particulate Emission Measurements . . 204
Appendix F - References Used in the Appendices 205
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LIST OF TABLES
TABLE NO. TITLE PAGE NO.
III-l Specifications of Fuels Used 28
III-2 Model and Serial Numbers of
Catalysts Tested 29
IV-1 Average Sulfate Emission Rates (Initial
and Final 1975 FTP) From NOX Reduction
Catalyst Vehicle, and Base Case Vehicle .... 43
IV-2 Comparison of Gaseous Emission Rates of
Vehicle Equipped with Engelhard Pelletized
Oxidation Catalyst Operated on 0.019 Wt. %
S Fuel 58
IV-3 Emission Rate of Indicated Exhaust
Component, gms/km for Test Runs
Following Standard Conditioning (A)
and Storage Conditioning (B) 59
IV-4 Storage Experiments, Pelletized Engelhard
Catalyst, 0.019 Wt. % S Test Fuel 59
IV-5 Standard Screening Tests, Pelletized Engelhard
0.019 Wt. % Test Fuel 60
IV-6 Relation of Bound Water to Sulfate
Emissions 61
IV-7 Estimated Maximum Emission Rates of Non-
Sulfate Sulfur Exhaust Particulate 65
IV-8 Relative Emission Rates, Total Metal
Oxides to Sulfates for Oxidation
Catalyst Equipped Vehicles 75
IV-9 Maximum Possible Platinum Emission Rates. ... 76
IV-10 Comparison of Metal Oxide Emission Rates;
Vehicle Equipped with Pelletized Engelhard
Oxidation Catalyst, Test Fuel 0.019 Wt. % S . . 93
IV-11 Comparison of Carbon and Total Particulate
Emissions 95
IV-12 Estimated Average Maximum Emission Rates
as Determined by Detection Limits 98
IV-13 Comparison of Total Particulate Emission
Rates, Andersen Impactor Versus Total
Filter 112
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vi
TABLE OF FIGURES
FIGURE NO. TITLE PAGE NO.
II-l Exhaust Partlculate Sampler 8
II-2 Schematic of Dehumldification Section. ... 10
II-3 Counter Current Exhaust Injection
System 12
II-4 Dew Point of Diluted Exhaust Vs.
Air/Exhaust Dilution Ratio 18
II-5 Relative Humidity of Exhaust Dilution Air
Mixture at Vicinity of Sampling Probes
During the 1972 Federal Test -
Driving Cycle 19
II-6 Temperature Control System Performance -
Catalyst-Equipped Car 20
II-7 Relative Humidity of Exhaust Dilution Air
Mixture at Vicinity of Sampling Probes
During 64 km/hr. Cruise Conditions 22
II-8 Finned Tube Cooling Setup 23
IV-1 Dependence of Total Particulate Emission
Rates, gins/km, on Fuel Sulfur Content
(Average of Initial and Final 1975 FTP)
Base Case Vehicle, 4 Monoliths 34
IV-2 Dependence of Total Particulate Emission
Rates, gins/km, on Fuel Sulfur Content
(Average of Initial and Final 1975 FTP)
Base Case Vehicle, 3 Pelletized
Catalysts 34
IV-3 Dependence of Total Particulate Emission
Rates, gms/kxn on Fuel Sulfur Content
(Average of Initial and Final 1975 FTP)
Base Case Vehicle, 2 NOX Reduction
Catalysts 36
IV-4 Dependence of Total Particulate Emission
Rates, gins/km on Fuel Sulfur Content
Monolithic Catalyst-Equipped Vehicles
64 km/hr. Cruise 36
IV-5 Dependence of Total Particulate Emission
Rates, gins/km on Fuel Sulfur Content,
Pelletized Catalysts, 64 km/hr. Cruise ... 37
IV-6 Dependence of Total Particulage Emission
Rates, gins/km on Fuel Sulfur Content
with NOx Reduction Catalysts,
64 km/hr Cruise 37
IV-7 Dependence of Total Particulate Emission
Rates, gins/km on Fuel Sulfur Content
Monolithic Catalyst-Equipped Vehicle
(96 or 113 km/hr. Cruise) 38
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vli
TABLE OF FIGURES (CONT.)
FIGURE NO. TITLE PAGE NO.
IV-8 Dependence of Total Particulate
Emission Rates, gms/km on Fuel Sulfur
Content Pallatized Catalyst-Equipped
Vehicle (96 or 113 km/hr. Cruise) 38
IV-9 Dependence of Total Particulate Emission
Rates, gms/km on Fuel Sulfur Content,
NOX Reduction Catalyst-Equipped Vehicle
(96 km/hr. Cruise) 40
IV-10 Sulfate Emission Rate vs. Fuel Sulfur
Content (Average of Initial and Final
1975 FTP) Base Case and Monolithic Oxidation
Catalyst-Equipped Vehicle 40
IV-11 Sulfate Emission Rates vs. Fuel Sulfur
Content (Average of Initial and Final 1975
FTP) Base Case and Pelletized Oxidation
Catalysts 41
IV-12 Dependence of Sulfate Emission Rates,
gms/km on Fuel Sulfur Content Monolithic
Catalyst-Equipped Vehicle
64 km/hr Cruise 41
IV-13 Dependence of Sulfate Emission Rates,
gms/km on Fuel Sulfur Content, Pelletized
Catalyst-Equipped Vehicle
64 km/hr Cruise 42
IV-14 Sulfate Emission Rates vs. Fuel Sulfur
Content, Base Case and Monolithic Oxidation
Catalysts (96 or 113 kra/hr Cruises) 42
IV-15 Sulfate Emission Rates vs. Fuel Sulfur
Content, Base Case and Pelletized Oxidation
Catalysts (96 or 113 km/hr Cruises) 44
IV-16 Dependence of Sulfate Emission Rates
on Fuel Sulfur Content, Vehicle Equipped
with NOX Reduction Catalysts,
64 km/hr Cruise 44
IV-17 Dependence of Sulfate Emission Rates,
gms/km on Fuel Sulfur Content, Vehicle
Equipped with NOx Reduction Catalysts
96 km/hr Cruise 45
IV-18 S02 and Sulfate Emissions for Monolithic
Catalysts for the 1975 FTP 47
IV-19 S02 and Sulfate Emissions for Monolithic
Catalysts at 64 km/hr Cruise 48
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viii
TABLE OF FIGURES (CONT.)
FIGURE NO. TITLE PAGE NO.
IV-20 S02 and Sulfate Emissions for Monolithic
Catalysts at 96-113 km/hr Cruise 49
IV-21 S02 and Sulfate Emissions for Pelleted
Catalysts for the 1975 FTP 50
IV-22 S02 and Sulfate Emissions for Pelleted
Catalysts at 64 km/hr Cruise 51
IV-23 S02 and Sulfate Emissions for Pelleted
Catalysts at 96-113 km/hr Cruise 52
IV-24 S02 and Sulfate Emissions for NOX Reduction
Catalysts for the 1975 FTP 53
IV-25 S02 and Sulfate Emissions for NOx Reduction
Catalyst at 64 km/hr Cruise 54
IV-26 S02 and Sulfate Emissions for NOx Reduction
Catalysts at 96 km/hr Cruise 55
IV-27 Equilibrium % Composition-Relative Humidity
Curve for Aqueous H2S04 at 20°C 62
IV-28 Scanning Electron Micrograph of Absolute
Filter from Andersen Impactor 64
IV-29 Scanning Electron Micrograph of Total
Filter Containing 125 mg of Sulfate .... 64
IV-30 Total Metal Oxide Emission Rates, gins/km
Obtained with Indicated Catalyst, Initial
and Final 1975 FTP on Each Test Fuel. ... 58
IV-31 Metal Oxide Emission Rates, gms/km vs.
Fuel Sulfur Wt. % on Steady State Cruises,
Engelhard Monolith 70
IV-32 Metal Oxide Emission Rates, gms/km vs.
Fuel Sulfur, Wt. % on Steady State Cruises,
UOP (1) Monolith 70
IV-33 Metal Oxide Emission Rates, gms/km vs.
Fuel Sulfur, Wt. % on Steady State Cruises,
UOP (2) Monolith 71
IV-34 Metal Oxide Emission Rates, gms/km vs.
Fuel Sulfur, Wt. % on Steady State Cruises,
Matthey-Bishop Monolith 71
IV-35 Metal Oxide Emission Rates, gms/km vs. Fuel
Sulfur, Wt. % on Steady State Cruises,
Engelhard Pellet 72
IV-36 Metal Oxide Emission Rates, gms/km vs. Fuel
Sulfur, Wt. % on Steady State Cruises,
Grace Pellet 72
IV-37 Metal Oxide Emission Rates, gms/km vs.
Fuel Sulfur, Wt. % on Steady State Cruises,
Air Products Pellet 73
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IX
TABLE OF FIGURES (CONT.)
FIGURE NO. TITLE PAGE NO.
IV-38 Metal Oxide Emission Rates, gms/km
vs. Fuel Sulfur Wt. %, on Steady
State Cruises, Grace NOX
Reduction Catalyst 73
IV-39 Metal Oxide Emission Rates, gms/km
vs. Fuel Sulfur, Wt. % on Steady
State Cruises, Gould NOX
Reduction Catalyst 74
IV-40 Aluminum Emission Rates, gms/km
Obtained with Indicated Catalysts,
Initial 1975 FTP 77
IV-41 Lead Emission Rates, gms/km
Obtained with Indicated Catalysts,
Initial 1975 FTP 78
IV-42 Lead Emission Rates, gms/km
Obtained with Indicated Catalysts,
Final 1975 FTP 80
IV-43 Lead Emission Rates at 64 and 96 km/hr
Obtained with Indicated Catalyst 81
IV-44 Iron Emission Rates, gms/km
Obtained with Indicated Catalysts,
Initial 1975 FTP 83
IV-45 Nickel Emission Rates, gms/km
Obtained with Indicated Catalysts,
Initial 1975 FTP 85
IV-46 Nickel Emission Rates, gms/km
Obtained with Indicated Catalysts,
Final 1975 FTP 86
IV-47 Copper Emission Rates, gms/km
Obtained with Indicated Catalysts,
Initial 1975 FTP 87
IV-48 Copper Emission Rates, gms/km
Obtained with Indicated Catalysts,
Final 1975 FTP 88
IV-49 Zinc Emission Rates, gms/km
Obtained with Indicated Catalysts,
Initial 1975 FTP 90
IV-50 Calcium Emission Rates, gms/km
Obtained with Indicated Catalysts,
Final 1975 FTP 91
IV-51 Chromium Emission Rates, gms/km
Obtained with Indicated Catalysts,
Initial 1975 FTP 92
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TABLE OF FIGURES (GOUT.)
FIGURE NO. TITLE PAGE NO.
IV-52 Size Distribution of Total Particulate,
Base Case Vehicle, 1975 FTP, Run No. 6 . . 101
IV-53 Size Distribution of Total Particulate,
Base Case Vehicle, 113 km/hr Cruise,
Run No. 9 101
IV-54 Size Distribution of Total Particulate,
Base Case Vehicle, 113 km/hr Cruise,
Run No. 14 102
IV-55 Size Distribution of Total Particulate,
Base Case Vehicle, 1975 FTP,
Run No. 15 102
IV-56 Size Distribution of Total Particulate
Base Case Vehicle, 64 km/hr Cruise
Run No. 29 103
IV-57 Size Distribution of Total Particulate,
Matthey-Bishop Catalyst-Equipped Vehicle,
64 km/hr Cruise, Run No. 88 103
IV-58 Size Distribution of Total Particulate,
Grace Palletized Catalyst-Equipped
Vehicle, 64 km/hr Cruise, Run No. 133. . . 104
IV-59 Size Distribution of Total Particulate,
Grace Palletized Catalyst-Equipped
Vehicle, 64 km/hr Cruise, Run No. 138. . . 104
IV-60 Size Distribution of Total Particulate,
Air Products Palletized Catalyst-Equipped
Vehicle, 1975 FTP, Run No. 160 105
IV-61 Size Distribution of Total Particulate,
Air Products Palletized Catalyst-Equipped
Vehicle, 1975 FTP, Run No. 166 105
IV-62 Size Distribution of Total Particulate,
Grace Reduction Catalyst-Equipped Vehicle,
1975 FTP, Run No. 96 106
IV-63 Size Distribution of Total Particulate,
Grace Reduction Catalyst-Equipped Vehicle,
1975 FTP, Run No. 101 106
IV-64 Size Distribution of Total Particulate,
Gould Reduction Catalyst-Equipped Vehicle,
64 km/hr Cruise, Run No. 113 107
IV-65 Size Distribution of Total Particulate,
Gould Reduction Catalyst-Equipped Vehicle,
1975 FTP, Run No. 120 107
IV-66 Size Distribution of Total Particulate,
Grace Reduction Catalyst-Equipped Vehicle,
64 km/hr Cruise, Run No 103 108
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xi
TABLE OF FIGURES (CONT.)
FIGURE NO. TITLE PAGE NO.
IV-67 Size Distribution of Total Particulate,
Gould Reduction Catalyst-Equipped Vehicle,
1975 FTP, Run No. 125 108
IV-68 Size Distribution of Total Particulate,
Engelhard Pelletized Catalyst-Equipped
Vehicle, Second 1975 FTP After Sulfate
Storage Conditioning, Run No. 175 109
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xii
LIST OF APPENDIX TABLES
TABLE TITLE PAGE NO.
A-l Comparative Titratlons of Sulfate of Samples
With and Without Nitric Acid 119
A-2 Experiments Demonstrating Influence of
Ion Exchanger on Sulfonazo III End Points .... 120
A-3 Comparison of Titrimetric and Gravimetric
504° Analysis on Parallel Filters 121
A-4 SO2 Measurements at Indicated Oxygen
Concentrations 126
A-5 Composite Effects of C02, 02, and CO
on TECO S02 Response 127
A-6 Estimated Average Maximum Emission Rates
(gins/km) As Determined by Detection Limit
of Spot Test on Indicated Vehicle Test 136
A-7 Effects of Presence of Other Metals on
Determination of a Selected Metal
(0.45 to 4.5 ygms/cm2 Calibration Curve) 155
A-8 Platinum-Chromium Interference 156
B-l Comparison of Impactor and Total Filters
(64 km/hr. Cruise) 159
B-2 Distribution of Partlculate in Modified
Andersen Impactor (64 km/hr. Cruise) 159
B-3 Comparison of Impactor and Total Filters
(96 km/hr. Cruise) 161
B-4 Distribution of Particulate in Modified
Andersen Impactor (96.54 km/hr Cruise) 161
C-l Performance of Exhaust Splitter on Lab Air. . . . 164
E-l Gaseous Emissions Unequipped Mileage
Accumulation Vehicle 170
E-2 Gaseous Emissions Unequipped Test Vehicle 171
E-3 Gaseous Emissions Engelhard Monolithic
Oxidation Catalyst-Equipped Vehicle 172
E-4 Gaseous Emissions Engelhard Palletized
Oxidation Catalyst-Equipped Vehicle 173
E-5 Gaseous Emissions UOP (1) Monolithic
Oxidation Catalyst-Equipped Test Vehicle 174
E-6 Gaseous Emissions Matthey-Bishop Monolithic
Oxidation Catalyst-Equipped Test Vehicle 175
E-7 Gaseous Emissions Grace NOX Reduction
Catalyst-Equipped Vehicle 176
E-8 Gaseous Emissions Gould NOX Reduction
Catalyst-Equipped Vehicle 177
E-9 Gaseous Emissions Grace Pallatized
Oxidation Catalyst-Equipped Vehicle 178
E-10 Gaseous Emissions UOP (2) Monolithic
Oxidation Catalyst-Equipped Vehicle 179
E-ll Gaseous Emissions Air Products Palletized
Oxidation Catalyst-Equipped Vehicle 180
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xiii
LIST OF APPENDIX TABLES (CONT.)
TABLE TITLE PAGE NO.
E-12 Gaseous Emissions, Test Vehicle Equipped
With Engelhard Palletized Oxidation Catalyst
After Catalyst Was Conditioned on a
0.091% S Fuel for 3200 km on the Federal
Durability Cycle 181
E-13 Gaseous Emissions, Test Vehicle Equipped
With Engelhard Monolithic Oxidation
Catalyst 181
E-14 Metal Derived Exhaust Particulate Emissions
Base Case Runs With Unequipped Mileage
Accumulation Vehicle Runs (1-15) and
Unequipped Test Vehicle Runs (16-30) 182
E-15 Metal Derived Exhaust Particulate Emissions
Test Vehicle Equipped With Engelhard
Monolithic Oxidation Catalyst 183
E-16 Metal Derived Exhaust Particulate Emissions
Test Vehicle Equipped With Engelhard
Pelletized Oxidation Catalyst 184
E-17 Metal Derived Exhaust Particulate Emissions
Test Vehicle Equipped With UOP (1) Monolithic
Oxidation Catalyst 185
E-18 Metal Derived Exhaust Particulate Emissions
Test Vehicle Equipped With Matthey-Bishop
Monolithic Oxidation Catalyst 186
E-19 Metal Derived Exhaust Particulate Emissions
Test Vehicle Equipped With Grace Reduction
Catalyst 187
E-20 Metal Derived Exhaust Particulate Emissions
Test Vehicle Equipped With Gould NOX Reduction
Catalyst 188
E-21 Metal Derived Exhaust Particulate Emissions
Test Vehicle Equipped With Grace Pelletized
Oxidation Catalyst 189
E-22 Metal Derived Exhaust Particulate Emissions
Test Vehicle Equipped With UOP (2)
Monolithic Oxidation Catalyst 190
E-23 Metal Derived Exhaust Particulate Emissions
Test Vehicle Equipped With Air Products
Pelletized Oxidation Catalyst 191
E-24 Metal Derived Exhaust Particulate Emissions
Test Vehicle EQuipped With Engelhard
Pelletized Oxidation Catalyst After
Conditioning on 0.091% Sulfur Fuel for
6400 Kilometers on Federal Durability Cycle . . 192
E-25 Sulfate Emissions Unequipped Mileage
Accumulation Vehicle 193
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xiv
LIST OF APPENDIX TABLES (CONT.)
TABLE TITLE PAGE NO.
E-26 Sulfate Emissions Unequipped Test Vehicle . . . 194
E-27 Sulfate Emissions Test Vehicle Equipped
With Engelhard Monolithic Oxidation Catalyst. . 195
E-28 Sulfate Emissions Test Vehicle Equipped
With Engelhard Pelletized Oxidation Catalyst. . 196
E-29 Sulfate Emissions Test Vehicle Equipped
With UOP (1) Monolithic Oxidation Catalyst. . . 197
E-30 Sulfate Emissions Test Vehicle Equipped
With Matthey-Bishop Monolithic Oxidation
Catalyst 198
E-31 Sulfate Emissions Test Vehicle Equipped
With Grace NOX Reduction Catalyst 199
E-32 Sulfate Emissions Test Vehicle Equipped
With Gould NOX Reduction Catalyst 200
E-33 Sulfate Emissions Test Vehicle Equipped
With Grace Pelletized Oxidation Catalyst. . . . 201
E-34 Sulfate Emissions Test Vehicle Equipped
With UOP (2) Monolithic Oxidation Catalyst. . . 202
E-35 Sulfate Emissions Test Vehicle Equipped
With Air Products Pelletized Oxidation
Catalyst 203
E-36 Sulfate Emissions After Storage 204
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XV
LIST OF APPENDIX FIGURES
FIGURE NO. TITLE PAGE NO.
A-l Recovery of Sulfate From Spiked Glass
Fiber Filter Samples 122
A-2 Principle of Operation TECO S02
Instrument 124
A-3 Permatube Drying System 125
A-4 Perkin-Elmer Model 240 C/H/N Microanalyzer. . . 126
A-5 Analytical Scheme for Nitrogen
Compounds in Auto Exhaust Particulate 132
A-6 Analytical Scheme for Sulfur Compounds
in Exhaust Particulate 133
A-7 Calibration Curve for Nickel 140
A-8 Calibration Curve for Aluminum 141
A-9 Calibration Curve for Calcium 142
A-10 Calibration Curve for Copper 143
A-ll Calibration Curve for Chromium 144
A-12 Calibration Curve for Zinc 145
A-13 Calibration Curve for Lead 146
A-14 Calibration Curve for Iron 147
A-15 Calibration Curve for Platinum 148
A-16 False Platinum Response of Quantometer
Due to Presence of Chromium 151
A-17 Calibration Curve for Lead
(4.5 to 11.25 ygms/cm2) 152
A-18 Calibration Curve for Iron
(4.5 to 11.25 pgms/cm2) 153
A-19 Calibration Curve for Zinc
(4.5 to 11.25 ugms/cm2) 154
B-l Oxidation Catalyst-Equipped Vehicle 160
C-l Schematic of Exhaust Splitter 163
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SUMMARY
A program to measure and characterize exhaust particulate
emissions from a vehicle equipped with a variety of commercial and
prototype catalyst systems was carried out. Nine catalysts (four
monolithic oxidation catalysts, three palletized oxidation catalysts,
and two NOX reduction catalysts) were screened on three test fuels.
The oxidation catalysts were representative of those used on 1975
production vehicles; the NOx reduction catalysts, candidates for use in
automotive emission control systems. The fuels used were an EPA-supplied
reference fuel containing 21% aromatics, that fuel plus an additives
package, and a 46% aromatics fuel with the additives package.
A rigorous conditioning procedure was carried out on both
catalysts and the vehicle prior to emissions testing to minimize the
effects of prior history on emissions. The vehicle was then operated
through a series of cyclic and steady state tests on each of the three
test fuels. Emission rates of CO, HC, NOX, and 862 were measured in
each test mode. Total particulate emission rates were measured using
the CVS compatible exhaust particulate sampler developed at Exxon
Research. Particulate samples were analyzed for sulfate, carbon, bound
water, nine metals, organic nitrogenous compounds, and organic sulfur
compounds.
The following results were obtained with oxidation catalysts:
Total particulate emission rates increased due
to the production of sulfuric acid aerosol by
catalytic oxidation of exhaust S02- This sulfuric
acid aerosol and its associated bound water, was
the major component of the particulate emitted.
As a result, total particulate emission rate varied
approximately linearly with fuel sulfur content.
By contrast, particulate emissions from the vehicle
without catalysts were independent of fuel sulfur
level.
The mass median equivalent diameter of catalyst
exhaust particulate decreased relative to the non-
catalyst case because submicron sulfuric acid
aerosol was the predominant component of the
particulate.
Preliminary results of sulfate storage experi-
ments indicate that released sulfate may have a
larger particle size than sulfate produced during
a run. Under certain conditions, the quantity
of stored sulfate released may be several times
that of freshly produced emitted sulfate. The
emitted sulfate after storage conditioning may
have two particle size distributions such that
stored sulfate has a larger mass median equiva-
lent diameter than freshly produced emitted
sulfate. Further work is needed to substantiate
these results.
Pelletized catalysts store sulfate during certain
test modes. Release of this stored sulfate can
persist for several test runs, resulting in
sulfate yields considerably in excess of 100%
based on the sulfur in the fuel consumed.
-------
- 2 -
The differences in particulate carbon content between
conventional and catalyst-equipped vehicles were smaller
than expected, particularly under cyclic operating con-
ditions, possibly because the presence of an air pump on
the conventional vehicle lowered particulate carbon
emissions. The carbon emission rates for oxidation
catalyst equipped vehicles operating on 0.019 wt.%
sulfur fuel ranged from zero to 0.019 gms/km and averaged
about 30% of the total particulate. Carbon emission rates
were independent of fuel sulfur content, the relative
contribution of this particulate component decreasing
with increasing fuel sulfur content.
The emission rate of some metals was raised as a result
of oxidation catalysts. The increment was not enough to
influence total particulate emissions.
- Aluminum emissions were higher, increasing from about
5 x 10~5 gms/km for the conventional vehicle to rates
occasionally as high as 4.5 x 10"^ gms/km. The
increase may be due to a low level of catalyst attrition.
- Iron emissions were substantially higher, increasing
from about 10~3 gms/km for the conventional vehicle to
rates exceeding 5 x 10~3 gms/km for oxidation catalyst
equipped vehicles. The increased iron emissions are
probably due to reaction between the sulfate formed
over the catalyst and the exhaust system. Iron emissions
were independent of the amount of sulfuric acid emitted
indicating that the reaction was wall (iron) limited.
- Zinc emissions also increased. The source of the zinc
was not determined.
- Platinum was not detected in the exhaust particulate
indicating that the emission rate must be below
5 x 10~*> gms/km.
With NOX reduction catalysts, it was found that:
Particle size distribution of the emitted particulate
resembles that of a non-catalyst car, if conditions are
not leaner than stoichiometric, when sulfuric acid aerosol
is formed. In the latter case, mass median equivalent
diameter is similar to that of atn oxidation catalyst-
equipped vehicle.
Nickel emission rates with a Gould NOX reduction catalyst
equipped vehicle were as high as 2 x 10~3 gms/km. With a
conventional vehicle or an oxidation catalyst equipped
-------
- 3 -
vehicle, nickel emission rates averaged about 2 x 10~^ gins/km.
However, the increased nickel emission rates obtained with the
NOX reduction catalyst may have been due to improper operation of
the vehicle at stoichiometric or net lean A/F ratios.
The following results were found to be independent of whether
the vehicle was operated with or without a catalyst:
Calcium emission rates correlated with expected lubricating
oil consumption rates. Calcium was not a significant
exhaust particulate, the emission rate averaging about
1 x 10~4 gins/km.
Leaded particulate emission rates for the unequipped
and catalyst-equipped vehicle were similar and were
equivalent to about 50% of the lead burned.
No nitrogenous organic particulate matter, either
additive or otherwise derived, was found.
Sulfate was the only sulfur containing exhaust
particulate found.
Particulate emissions did not increase when the
fuel aromatic content was increased from 21 to 46%,
indicating that the carbon particulate emission rate was
independent of fuel aromatic content.
The major effect of catalysts used for automotive emissions
control on exhaust particulate emissions are the production of sulfuric
acid aerosol, and some increase in metal derived emissions, mainly those
containing iron. Sulfates and associated bound water are the predom-
inant components of exhaust particulate, followed by minor quantities
of organic particulate and metal derived particulate. The relative
contributions of the latter two types of particulate decreases with
increasing fuel sulfur content.
-------
I. INTRODUCTION
Automotive particulate emissions are of concern because of
the potentially deleterious effects to health as a result of their accumula-
tion in the atmosphere. Particulates also reduce atmospheric visibility,
are known to be the cause of increased soiling, and may also function as
photosensitizers in smog forming reactions. In 1975, approximately
75% of the cars produced will be equipped with oxidation catalysts
in order to control carbon monoxide and hydrocarbon emissions. In
addition to reducing these pollutants, prototype systems were also
shown to have further beneficial results, namely the reduction of un-
regulated emissions such as aldehydes, reactive hydrocarbons(1), and
polynuclear aromatic hydrocarbons(2) to extremely low levels.
Particulate emissions from catalyst equipped vehicles however
could differ markedly from that of conventional vehicles. For example,
thermal and mechanical stresses of the catalyst and/or substrate could
result in the presence of these materials in vehicular exhaust. Chem-
ical conversion of catalyst and substrate material to a mobile condensed
phase is another possible route for these materials to show up in
vehicular exhaust. Finally, catalytic conversion of gaseous exhaust
components to particulate matter could produce new exhaust components,
not normally present in the exhaust of conventional vehicles. Sulfate
aerosol is an example of a catalytically produced exhaust component
not normally present in significant quantities in exhaust from con-
ventional vehicles. This aerosol is produced by the catalytic oxidation
of exhaust sulfur dioxide.
This report describes the first phase of a contract work
program to study particulate emissions from catalyst equipped vehicles
The major objectives of this program are the measurements and characteriza-
tion of exhaust particulate emissions from a variety of catalyst systems
(commercial and prototype) that may be used in automotive emission
control. To this end, it was necessary to measure and characterize
particulate emissions from vehicles in their conventional configuration
prior to equipping them with catalysts in order to distinguish between
vehicle and catalyst effect on total particulate emissions.
The first phase of this contract work was primarily a catalyst
screening program. The catalysts selected for testing were those most
likely to be used in commercial vehicles. Nine catalyst systems (four
monolithic oxidation catalysts, three beaded oxidation catalysts,
and two NO reduction catalysts) were tested with three fuels.
A
The three fuels used were a reference fuel supplied by EPA,
that same fuel with an additive package, and a high aromatic fuel
which also contained the additive package. This fuel selection was
made so that exhaust particulate could be characterized as follows:
(1) level and composition of exhaust particulate from the use of an
additive-free fuel in conventional and catalyst equipped vehicles.
-------
- 5 -
(2) effect of fuel additives on particulate emissions from conventional
and catalyst equipped vehicles,
(3) effect of a high aromatic fuel containing additives on particulate
emissions from conventional and catalyst equipped vehicles.
Two matched 1974 - 350 CID (5.735 liter) Chevrolet V-8
vehicles equipped with air pumps and exhaust manifold air injection
systems were used. One vehicle was used for all the particulate
emission measurements, the other for conditioning and aging the catalysts.
A rigorous conditioning schedule prior to testing was carried
out since it has been shown that particulate emissions, particularly
sulfate emissions, are a sensitive function of vehicle history. Each
of the catalysts was mounted on the test vehicle and conditioned for
3218 km (2,000 miles) on a Mileage Accumulation Dynamometer (MAD) over
the Federal Durability Cycle using an eight-hour on, eight-hour off
sequence. The conditioning fuel was different from the test fuel
because of limited supply of test fuels. Prior to testing with a given
fuel, the vehicle was operated on that fuel for 200 miles on the MAD
using the Federal Durability Cycle, followed by a sixteen-hour cold
soak.
The vehicle was then operated through the following series of
tests on each of the three test fuels:
(1) 1975 FTP
(2) One hour idle
(3) One hour, 64 km/hr (40 mph) cruise
(4) Two hour, 113 km/hr (70 mph) cruise or a two hour, 96 km/hr
(60 mph) cruise
(5) Overnight soak
(6) 1975 FTP
Gaseous emission rates (CO, hydrocarbon, NO , and SO ) were measured
in each test. Total particulate emission rites were measured in each
test using the CVS compatible exhaust particulate sampler developed at
Exxon (3).
Analyses of the particulate samples were carried out to determine
the emission rates of the following:
Sulfate
Carbon
Calcium
Aluminum
Zinc
Chromium
-------
- 6 -
Iron
Copper
Nickel
Lead
Platinum
Bound Water
Chemical analysis was carried out to determine the presence of non-
sulfate sulfur particulate matter and for the presence of nitrogenous
organic matter in exhaust particulate. Particulate size distribution
determinations were carried out using an Anderson Particle Sizing
Sampler.
-------
- 7 -
II. TECHNICAL BACKGROUND
In this section, automotive particulate emissions will be
briefly discussed, the exhaust particulate sampling system developed
at Exxon will be described, as well as the capabilities of the sampling
sys tern.
II.1 Automotive Particulate Emissions
In this report, automotive particulate emissions are defined
as any material, other than unbound water, emitted from a vehicle tailpipe
which exists in the condensed state at 32°C (90°F), that is larger than
a small molecule but less than 500 microns in diameter. Exxon Research
has used this definition of exhaust particulate since it was used by
EPA in a work statement of a 1972 Request for Proposal to "Design,
Develop, Fabricate and Test a Device Compatible with the Constant
Volume Sampling System which will Allow Simultaneous Measurement of
Gaseous and Particulate Emissions from Light Duty Vehicles"(4).
II.2 Exhaust Particulate Sampling System
The exhaust particulate sampling system has been designed to
collect particulate matter at constant temperature during the 1972 and
1975 Federal Test Procedure, and 64 km/hr (40 mph) cruise conditions.
This system is capable of frequent and convenient operation, and is
compatible with constant volume sampling (CVS) of auto exhaust.
Compatibility is obtained because the particulate sampler requires
only a small portion of the diluted exhaust, the major portion of the
sample is available to the CVS system for the measurement of gaseous
emissions. Conditions used in the measurement of exhaust particulate
conform to those mandated by the Federal Test Procedures for gaseous
emissions.
This sampling system uses a small tunnel which means that low
dilution ratios are used, allowing gaseous emissions such as CO, hydro-
carbons, NOX and SC>2 to be measured accurately. While low dilution
ratios are desirable from the standpoint of CVS gaseous emission
measurements, the collection of a proportional sample of particulate
matter at constant temperature 32°C (90°F) from a sample stream having
a high dew point without causing condensation of water requires an
advanced temperature control system.
II.2.1 Sampling System Components
The particulate sampler which has been discussed previously(3,5)
is shown schematically in Figure II-I. This system has five major
components:
1. A diluent air preparation system
2. A flow development tunnel
3. An exhaust Injector system
4. An isokinetic sampling probe
5. A particulate measuring device, which in the case shown
is a 0.2 micron glass fiber filter
-------
FIGURE II-1
EXHAUST PARTICULATE SAMPLER
INTAKE
DILUENT AIR
HEAT
EXCHANGER
DEHUMIDIFIER
FLOW
DEVELOPMENT
TUNNEL
MIXING
TURBULATORS
TO CVS
ROTOMETER I P"*
<
PUMP
i
00
I
EXHAUST
INJECTOR
ISOKINETIC
SAMPLING
PROBE
FILTER
HOUSING
-------
- 9 -
The overall function of this system is to allow the collection
of particulate matter from an isokinetically sampled portion of
diluted exhaust which has been cooled to 90°F by dilution with chilled,
dehumidified, filtered air. The function of each of the components in
accomplishing this objective is described below.
II.2.1.1 Diluent Air Preparation System
This system consists of a dehumidifier, filter, coupled mixing
baffles, a cooling system, and mixing turbulators.
The dehumidifier shown schematically in Figure II.2 minimizes
the possibility of condensation occurring in the sampling system during
a run, and is an integral part of the temperature control system.
Diluent air is dried by passage through a filter and a slowly rotating
desiccant wheel containing laminated flat and corrugated asbestos,
impregnated with a regenerable desiccant, Lid. Dehumidification of
diluent air and desiccant reactivation are concurrent processes, so that
dehumidification can be carried out on a continuous basis. The de-
humidifier, a Honeycombe Model HC 750-EA is manufactured by Cargocaire
Engineering Corporation is described in their Bulletin No. 07169(6).
Dehumidified inlet air passes from the dehumidifier to a filter
box containing a paper filter, a bed of activated charcoal, and a second
paper filter. This assembly is the standard filter box assembly for the
Scott Research Constant Volume Sampler (CVS) unit. The filter assembly
removes the particulate matter present in the diluent air and reduces
and stabilizes the background hydrocarbon content of the diluent air.
Because regeneration of the dessicant Is accomplished by
heating, the dehumidified air emerging from the drum is above ambient
temperature. A pre-cooler situated between the dehumidifier and the CVS
filter cools the dehumidified air stream down to ambient temperature to
remove the additional cooling load Imposed by the dehumidification step
from the final cooling system. The pre-cooler consists of several rows
of colls through which chilled city water is passed.
The coupled mixing baffles continuously divide the dehumidified,
filtered air into two portions, one which passes through the cooling
system, and a second portion which bypasses the cooling system. The
position of the mixing baffles is controlled by a rapid response, deviation-
type controller operating on an input signal from a thermocouple in the
filter housing. The system is designed to maintain 90°F at the filter
housing, during the 1972 or 1975 Federal Test Procedures, and 64 km/hr
cruise.
The controller operates by comparing an input signal from
a thermocouple in the filter housing with a set point signal, and
takes corrective action to either raise or lower the output signal until
the set point and thermocouple input are equal. The controller used was
an Electronic Control System Model 6700 Controller(7). The output signal
-------
FIGURE II-2
SCHEMATIC OF DEHUMIDIFICATION SECTION
REACTIVATION AIR
INLII^"-TER REACTIVATION
FAN
TO FILTER ^T
BOX _DV AyD DESICCANT
A DRYA'R REACTIVATION WHEEL
1 T AIR HEATER /.'I
V js N /
WET AIR OUTLET
A
M 1 '
REACTIVATION
SECTOR
r ^ J
^^ S
DRY AIR FAN
HUMID AIR
INLET
FILTER
o
i
-------
- 11 -
from the controller is fed to an electric to pneumatic transducer (8)
which in turn activates a pneumatic controller (9) which operates the
coupled baffles.
The cooling system is an air cooled condensing evaporator which
has a cooling capacity of 33,500 BTU/hour. The evaporator is a Dunham-
Bush, Model SCO-50C unit(10) containing ten rows of custom-made cooling
coils(11).
The mixing turbulators insure that chilled air is thoroughly
mixed with the portion of air bypassing the cooling system before the
stream is used to dilute the vehicle exhaust. The turbulators consist
of six semi-circular perforated plates attached to a 1/2" diameter
wall tube at their centers, arranged in a helical series sequence along
the tunnel axis. This arrangement allows both longitudinal and
latitudinal mixing.
Maximum flow through the diluent air preparation system is
determined by the cooling capacity of the chiller. Presently, this
limitation is 450 CFM.
II.2.1.2 Flow Development Tunnel
The exhaust and diluent air are mixed and a uniform velocity
profile is developed in the flow development tunnel. The flow develop-
ment tunnel is a 7.5 ft. long section of a 4-inch diameter Schedule 5
stainless steel pipe. Neither the length nor the diameter of the flow
development tunnel have been optimized, but as will be shown in another
section, a dilution tunnel of these dimensions is satisfactory for
this purpose.
II.2.1.3 The Exhaust Injection System
The raw exhaust is mixed with the diluent air normally used
in the CVS in such a way as to completely mix the two in as short a
time interval as possible. This is accomplished by injecting
the exhaust in a countercurrent direction to the diluent air stream.
Previous experiments(3) have shown this to be the most efficient way
of obtaining a rapidly mixed, uniformly distributed diluted exhaust sample
stream. Figure II-3 shows a schematic of the exhaust injector in the
countercurrent position.
II.2.1.4 Isokinetic Probe
Isokinetic sampling is required to insure that the particulate
sampled is representative of the particulate in the main stream; that is,
the particulate concentration and size distribution in the probe sample
should correspond to that of the main stream. The probes are designed
so that the sample stream is divided into two parts with a volume
ratio equal to the ratio of the cross-sectional areas of the openings
of the sample probes and the tunnel cross-sectional area. Hence,
-------
FIGURE II-3
COUNTER CURRENT EXHAUST INJECTION SYSTEM
TRICLOVER
CONNECTIONS
DILUTION
AIR
RAW EXHAUST
TAILPIPE CONNECTOR
DILUTED EXHAUST
4.3" ID S.S. FLOW
DEVELOPMENT
SECTION
T^^ _, , aiTLf -T- ,-LJI I * f'fl -f'~ -n -r -.*»'
\
COUNTERCURRENT
INJECTOR
-------
- 13 -
Area (probe) _ Flow Rate in SCFM (probe)
Area (tunnel) ~ Flow Rate in SCFM (tunnel)
Another problem to be considered in probe design is minimizing
sample deposition in the probes. When suspended particulate matter
leaves the tunnel and enters the sampling probe, it is leaving a low
surface to volume region and entering a high surface to volume region.
Relative sample losses by impaction should be greater in the probe
than in the tunnel. Therefore, the probe should be as short and
direct as possible to minimize the residence time of the particulate
matter in the probe. The filter housing connected to the probe is
flared out as soon as physically possible to minimize the surface to
volume ratio of the housing and thereby reduce sampling losses by impac-
tion in this portion of the sampling system.
II.2.1.5 Particulate Collecting Stage
At present, particulates are collected by filtering the sample
through pre-weighed filters. In principle, other particulate collectors
such as impactors and other devices, could be utilized with the
particulate sampling system. In this paper, total particulates are
determined gravimetrically using Gelman Type E glass fiber filters
which have an effective pore size of 0.2 y.
II.2.2 System Performance
In order to function properly, the exhaust particulate sampling
system should have the following capabilities:
(1) Mix exhaust and diluent air rapidly.
(2) Allow development of a uniform velocity profile in the
flow development tunnel.
(3) Minimize sampling losses in the tunnel.
(4) Give equivalent emission rates with parallel filters.
(5) Maintain constant temperature at the particulate
collecting stage.
All of the above have been adequately documented (3,5) and will be
reviewed In this section.
II.2.2.1 Rapid Mixing of Exhaust and Diluent Air
Three methods of injecting exhaust into diluent air were
tested: co-current flow, perpendicular flow, and countercurrent flow.
In each case, the exhaust was injected through a 2 in. O.D. x 0.035 in.
wall stainless steel tube into the flow development tunnel. The efficiency
of the three injection methods was tested by measuring hydrocarbon concen-
trations in the diluted exhaust at a point approximately 7.5 ft. downstream
of the injection point. Hydrocarbons were chosen as the tracer because
they are easier to measure than particulates. If the gaseous components
of the exhaust are not evenly distributed over the flow cross-section,
there is no reason to believe that the particulates will be well
distributed. The ultimate test of uniformity of particulate distribution
-------
- 14 -
in the tunnel is the consistent attainment of equivalent particulate
emission rates with parallel filters. The results showed that uniform
distribution was obtained only by countercurrent injection.
II.2.2.2 Development of Uniform Flow
in Flow Development Tunnel
To insure that samples taken at any point in the tunnel cross-
section will contain the same amount of particulate material, a uniform
radial distribution of particulate material in the tunnel must be obtained.
The small size of the tunnel would make it difficult to obtain reliable
measurements of velocity profiles. However, it is well known that the
higher the Reynolds Number of turbulent flow, the flatter the velocity
profile(12). However, over the range of interest for this system, the
effect of this flattening of the velocity profile is negligible.
Consider the system as having a flow of 450 SCFM of air at 90°F.through
a 4.33 in. diameter pipe.
V -g*-
where N = Reynolds Number
D = pipe diameter = 4.34 in. = 0.361 ft
U = average fluid velocity = 4 ^J"' = 4395 ft/min
5 '' °
2.64 x 10 ft/hr
P = density = 0.071 Ib/ft
/( = fluid viscosity = 0.186 cp = 0.045 Ib/ft-hr
N_ (0.361 ft) (2.64 x 105 ft/hr) (0.71 Ib/ft3) = .
Ke " 0.045 Ib/ft-hr J.3U.UUU
Equation (1) shows that the Reynolds Number varies inversely
with diameter for constant volumetric flow. Therefore, decreasing pipe
diameter to 1" would increase NRe to 615,000 while increasing pipe
diameter to 16" would decrease NRe to 40,000.
One measure of the flatness of the velocity profile is the ratio
of the mean gas velocity to the maximum gas velocity. It has been shown
experimentally that for turbulent flow in smooth pipes(12)
s. .(I)
U \R/
1/N
(2)
-------
- 15 -
where u = point velocity
U = maximum velocity at center
Y = distance from the wall
R = pipe radius, and
N = a constant depending on Reynolds Number
Schlicting (12) shows that average velocity 11 is,
2N2
u =
The following table shows that the effect of changing pipe diameter
over a large range would be negligible.
Effect of Reynolds Number
on Velocity Profile
N N TI/U
23,000 6.6 .807
110,000 7.0 .816
500,000 8.0 .837
It should be noted that Schlicting*s correlation is for a fully
developed boundary layer which probably does not exist in the tunnel.
Flow profiles are likely to be flatter than indicated above.
Another important factor in choosing the diameter of the
flow development tunnel is its effect on the length of the tunnel and
the diameter of the probes. As a general rule, ten pipe diameters
are usually sufficient to develop a fully turbulent velocity profile.
The larger the diameter, the longer the tunnel required and the longer
the residence time in the flow development section. Longer residence
time leads to higher particulate settling and greater inaccuracy in the
measurement. Therefore, the tunnel diameter should be minimized. How-
ever, as tunnel diameter decreases, the pressure drop through the tunnel
increases and the size of the probes needed for isokinetic sampling
decreases. The problems caused by high pressure drop are obvious.
Smaller diameter probes should be avoided since they provide higher
surface to volume ratios and result in more loss of particulate by impac-
tion. The 4.3 inch diameter pipe in use offers a reasonable compromise
between these various factors.
II.2.2.3 Tunnel Sampling Losses
Particulate deposition in the flow development section
was measured by Introducing an artifically produced mono-disperse (3.5
micron diameter) methylene blue aerosol into the exhaust injector in
the same manner as for auto exhaust. The system was disassembled after
the run, the tunnel surface washed with methanol and the washings analyzed
spectrophotometrically. The sensitivity of the method for methylene
blue is in ppb range. Analysis showed that tunnel losses are small,
amounting to less than 1% of the total aerosol introduced. No dye
was detected in the tunnel section housing the exhaust injector. About
-------
- 16 -
0.1% of the aerosol was deposited in the tunnel mid-section, and about
0.3% was deposited in the tunnel section housing the probes. Independent
tests by U.S. Environmental Protection Agency workers with a tunnel of
similar dimensions have confirmed our results regarding tunnel sampling
losses(13).
II.2.2.4 Equivalent Emission Rates with Parallel Filters
Since only a small fraction of the diluted exhaust is sampled
for the particulate analysis, at least two parallel probes coupled
to the appropriate filters are needed to serve as internal checks
on the sampling system. One method of determining whether proper sampling
is achieved relies on the ratio of the weight of particulate collected (W )
by filter A, and the volume flow rate (F.) through probe A. This ratio
should equal the corresponding ratio of these parameters for filter
B and probe B, that is:
WA WB WC
= = = etc.
A B C
The particulate emission rates in grams/kilometer (gms/km)
should be the same for all filters in a given run since
W 'F \ W / F \
gms _ A i _P 5 B I P j = etc.
km F ^ Akm / F \^Akm/
A, o
where Fp is the volume flow rate through the tunnel and Akm the
distance in kilometers accumulated on the particular test procedure.
Excellent agreement between parallel filters has been obtained
using this sampling system with conventional and catalyst equipped
vehicles operating on a variety of unleaded fuels under cyclic and state
test conditions. Partial documentation of this agreement has been
previously described(3,5).
II.2.2.5 Temperature Maintenance of the
Particulate Collection Stage
The dehumidifier is a key component of the temperature control
system, particularly since the sampling system is one in which the
air/exhaust dilution ratios are low, unlike other particulate sampling
systems(14,15). This means that the relative humidity of the diluent
air is a key parameter. For example, during the steep acceleration portion
of the Federal Test Procedure, the exhaust volume flow rate from a vehicle
equipped with a 350 CID V-8 engine may be as high as 120 CFM. This means that
-------
- 17 -
dilution ratio would drop below 3 in the sampling tunnel. If the
relative humidity of the diluent air was high, attempts to control the
filter temperature at 90°F would result in condensation of water vapor,
with the associated loss of particulate matter. This is shown in
Figure II-4 which depicts mixture dew point-dilution ratio dependence
as a function of the relative humidity of the diluent (24°C) air.
The key role of the dehumldifier can readily be seen. If
the relative humidity of the diluent air is low, e.g., below 50%,
it should be possible to maintain a 32°C (90°F) filter temperature with-
out condensation occurring. It can also be readily seen that in the
absence of the dehumidifier, on humid days, the dew point of the mixture
would exceed 32°C at dilution ratios as high as four, so that condensation
would invariably occur during the acceleration portions of the driving
cycle.
Attempts to control filter temperatures by omitting the
dehumidification step and chilling the diluent air would be difficult
to accomplish since water condensing on the coils would feed back
latent heat, decreasing the efficiency of the cooler. Continued
running would probably result in the condensed water freezing on the
heat exchangers, rendering them inoperative.
Figure II-5 shows a typical trace of the relative humidity
of the diluted exhaust in the vicinity of the sampling probes during
FTP operation with a catalyst equipped vehicle. This trace is obtained
by withdrawing a sample just above the sampling probes and filtering it
prior to monitoring the humidity. Filtration is necessary in order
to protect the rapidly responding humidity sensor(16).
It is evidentfthat the relative humidity in the region of
the probe closely parallels the changes in the cycle driving patterns.
At no 'point in the driving cycle does the relative humidity at the
probes reach the saturation level at 90°F. As the relative humidity
is lower upstream, condensation in the tunnel upstream of the probe
does not occur.
Figure II-6 shows the temperature-time trace at the filter
during the above run which is a typical case. A total flow rate of
about 450 SCFM was used. A four foot long 2 inch I.D. finned tube
between the tailpipe and the exhaust injector was needed to
suppress temperature spikes above 90°F during the steep acceleration
portion of the driving cycle. It should be noted that the system is
designed to prevent temperature excursions above 90°F, not to maintain
that temperature during the course of the entire run.
-------
FIGURE II-4
DEW POINT OF DILUTED EXHAUST VS.
AIR/EXHAUST DILUTION RATIO
At Indicated Relative Humidities
of 75°F (23.90C) Dilution Air
1 120 CFM @ Accel to 58 mph
2 Air Pump, EGR
900F (32.2QC) line
1.0
2.0
9.0 10.0
Dilution Ratio (Dilution Air/Raw Exhaust)
-------
FIGURE II-5
Np
tf»
RELATIVE HUMIDITY OF EXHAUST DILUTION AIR
MIXTURE AT VICINITY OF SAMPLING PROBES DURING
THE 1972 FEDERAL TESTDRIVING CYCLE
> 100
t
9ul 75
i§ 50
>< 25
5
d o
nfy\7fVAi^^
Q.
E
*
Q
u.1
UJ
Q.
VO
I
4 5 6 7 8 9 10
TIME, HUNDREDS OF SECONDS
12 13
-------
- 20 -
FIGURE II-6
TEMPERATURE CONTROL SYSTEM PERFORMANCE
CATALYST-EQUIPPED CAR
01
n
01
i-
110° -
90° -
70° -
450 CFM CHILLED AIR
SYSTEM WITH
FINNED TUBE
TIME DURING THE 1972 FTP
-------
- 21 -
Figure 11-7 is a typical relative humidity-time trace for
a 40 mph steady state cruise experiment. The relative humidity surges
to about 25% on start up and slowly decreases with running time.
Complete temperature control can be obtained at 40 mph by
encapsulating the finned tube in a 4-inch diameter metal cylinder
through which ambient air is pumped in a countercurrent direction
to the flow of raw exhaust. Figure II-8 shows a schematic of this
additional temperature control feature.. Encapsulating the finned
tube is not necessary for the driving cycle. At the 40 mph cruise,
however, the temperature would slowly rise above 90°F after about
20 minutes if the finned tube was not encapsulated.
II.2.2.6 Capabilities for Studying Effect
of Temperature on Particulate Collection
For the purposes of this work exhaust particulate matter is
collected at 90°F. However, particulate can also be collected at
other selected temperatures so that it would be useful for studying
the effect of temperature on the quantity of particulate collected
should the need arise.
This is because the set point temperature is essentially deter-
mined by the fraction of the dehumidified air that is cooled. If
collection at a higher temperature is desired, the fraction of
dehumidified air that goes through the heat exchanger is decreased.
This fraction is determined by the set point temperature and the actual
instantaneous temperature of the exhaust-dilution air mixture in the
filter housing.
Thus a range of particulate. collection temperatures is
possible, the lower limit being the dew point of the air-exhaust mix-
ture at the lowest dilution ratios, and the upper limit the minimum
amount of cooled-dehumidified air required to prevent temperature
increases, at low dilution ratios. To date, this range has not been
investigated.
-------
FIGURE II-7
100
> GJ 75
L.M ^^
9oi5
^OO 50
o
Ol
cc
0
RELATIVE HUMIDITY OF EXHAUST DILUTION
AIR MIXTURE AT VICINITY OF SAMPLING
PROBES DURING 64 kph= CRUISE CONDITIONS
at 32°C
5 10
TIME (MINUTES)
15
N>
N>
-------
- 23 -
FIGURE II-8
FINNED TUBE COOLING SETUP
Raw Exhaust
Outlet
HUM i ii 11 11 I Ml
MIN
INI I I Ml II II I I
To Exhaust
Injector
Cooling Fins
Air Inlet
-------
- 24 -
III. Experimental
III.l Test Vehicles
Two matched 1974 350 CID Chevrolets were used in this program.
These vehicles came equipped with air pumps and exhaust manifold air
injection systems. The engine specifications listed below were set to
manufacturer's specifications.
1974 Chevrolet 350 CID V-8
Spark plugs .035 in.
Points dwell 30° + 1
Basic Spark Timing 8° BTDC
Idle Speed 600 RPM, transmission in drive
Carburetor Rochester 2 barrel, No. 7044114
Horsepower 145 at 3600 RPM
Compression Ratio 8.5:1
III.1.1 Vehicle Conditioning Procedures
Both project vehicles when received were drained of the leaded
fuel contained in their fuel tanks. Their fuel systems were flushed to
remove all traces of the factory fuel. Both vehicles were then driven
by Exxon Research employees to accumulate about 3200 km (^ 2000 miles)
of commuter type mileage for initial break-in. The break-in fuel had a
sulfur content of less than 100 ppm and a lead level of about 0.05 gin/gal.
The specifications of the break-in fuel are given in Section III.2.2.
To complete the break-in procedure, the vehicles were then operated for
3218 km on Exxon Research's automated Mileage Accumulation Dynamometer
(MAD) using the Federal Mileage Accumulation Schedule (1). The 6400
kilometer accumulation had two purposes, to break in the vehicles, and
to purge any traces of lead deposits that could have accumulated in the
vehicle's combustion chambers and exhaust system over the few miles of
vehicle operation during assembly and transportation.
Both vehicles were run through a complete set of particulate
emission tests on all three test fuels to determine if there were any
major differences between the two vehicles with respect to emissions
(gaseous and particulate), and to establish base case engine particulate
emission rates in order to separate vehicle and catalyst contributions
to total particulate emissions.
One vehicle was then selected as the mileage accumulation
vehicle, the other as the test vehicle. Both vehicles and all catalyst
containers were fitted with quick disconnects to facilitate rapid inter-
change of catalyst systems between the mileage accumulation vehicle and
the test vehicle. The test procedure will be discussed in Section III.4.
-------
- 25 -
III.1.2 Catalyst Conditioning Procedures
All tests were initiated with the fresh catalysts mounted on
the mileage accumulation vehicle in their proper position (post manifold
or toeboard) depending on the catalyst configuration. The engine operating
variables (carburetor adjustment, spark timing, points dwell, points gap
and idle speed) were set according to the manufacturer's recommendations.
Each vehicle was periodically tuned; after each catalyst break-in for
the mileage accumulation vehicle, and after the battery of tests on a
given catalyst for the test vehicle.
The mileage accumulation vehicle was operated on the MAD for
about 2900 km (1800 miles) using the Federal Durability Driving Schedule
and the mileage accumulation fuel. Mileage was accumulated on an eight
hour on, eight hour off, basis to provide a cold start approximately
once every 320 kilometers. The assumption was that this procedure would
provide adequate thermal conditioning of the catalyst, and that the
repeated cold starts would also subject the catalyst to some degree of
thermal shock. After completion of the catalyst aging and conditions,
the catalyst was transferred to the emission test vehicle and operated
for 320 km (200 miles) using the Federal Durability Driving Schedule on
the first test fuel to be used for particulate emission measurements.
The purpose of the 320 km accumulation was to equilibrate
the catalyst with the test fuel. It was designed to eliminate any storage
factors associated with the break-in fuel that could Influence particulate
emissions, so that these emissions would be truly reflective of the
particular test fuel. It is quite probable that a 320 km accumulation
is not of sufficient length to obtain equilibrium, but the time and fuel
constraints placed on what is essentially a catalyst screening program
in the first phase of this contract work did not allow operation for
longer mileage in every test.
To more fully examine the storage problem, an additional test
was made on a beaded oxidation catalyst system in which after following
the normal test procedure, the catalyst-equipped vehicle was conditioned
for an additional 6400 km (4000 miles) with one of the high sulfur test
fuels to ascertain the effect of sulfate storage on particulate emissions.
This additional test and the results obtained are discussed in Section
IV.1.5.
Following the conditioning, the emission test vehicle was
cold soaked for 16 to 24 hours prior to starting the particulate emission
test procedure sequence. Control of the cold soak period allowed
reproducible particulate emissions from the same vehicle.
-------
- 26 -
After completion of the particulate emission measurement test
sequence on a given fuel, the vehicle was returned to the MAD to
accumulate 320 km using the second test fuel. After appropriate cold
soaking and emission testing, the vehicle was again returned to the
MAD to accumulate 320 km on the third test fuel. Emission measurements
were made which completed the screening of that catalyst.
III.2 Selection of Fuels
The contract required that three fuels be used in the tests,
a reference fuel supplied by EPA, that reference fuel plus an additives
package, and a high aromatic fuel to be blended at the Exxon facilities,
which contains the additive package. The aromatics level of the high
aromatic fuel was selected on the basis of what the likely market place
maximum would be.
III.2.1 The Additive Package
The contract required an additive package to be added to the
EPA Reference Fuel and to the high aromatic fuel. The contents of this
package were to contain the following:
0.05 g Pb/gal. as Motor Mix
Additional sulfur as a mixture of thiophene and
t-butyl disulfide to raise the sulfur content of
the fuel to 0.1 wt. %.
A nitrogenous multi-functional additive, and
A heavy carrier oil or polymer type additive.
Lead as motor mix was added to achieve a level of approximately
0.05 gms/gallon. Sulfur was added as a mixture of 50% thiophene, 50%
tertiary-butyl sulfide.
Lubrizol 596 (LZ596) was the nitrogenous multi-functional
additive used. This additive, manufactured by the Lubrizol Corporation
was used at the manufacturer's recommended maximum dosage, 25 Ibs. per
thousand barrels (0.27 g/gal.) LZ596 is a non-polymeric material
containing 2.25-2.75% nitrogen by weight. It functions as a detergent,
corrosion inhibitor, anti-stall agent, and anti-icing agent. Further
details on the nature of this material are considered confidential by
Lubrizol, but were filed with the EPA Air Pollution Control Office on
April 28, 1971.
Paradyne 502 was used for the polymer type additive. This
material, manufactured by the Exxon Chemical Company was used at the
recommended dosage of 42 Ibs. per thousand barrels (0.45 g/gal. Paradyne
502 is an approximately 3000 molecular weight polymer which contains
-------
- 27 -
0.75% nitrogen by weight. It functions as a detergent, anti-rust
agent and deposit modifier. As in the case of LZ 596, further details
on the na.ture of this additive are confidential but are on file with
the EPA Office of Air Pollution Control as of April 28, 1971
Because of the limited supply of test fuels for this program,
a separate break in fuel for both vehicles and catalysts prior to testing
was used. This fuel was to contain 0.05 gm Pb/gal. and less than 100
ppm sulfur, have normal volatility characteristics, and an octane level
of at least 93 RON.
III.2.2 Fuel Specifications
Table III-l shows the specifications of the break in fuel and
the test fuels. Fuel (1) is the EPA reference fuel, fuel (2) that
fuel spiked with the additive package, and fuel (3) the high aromatic
fuel containing the additive package. Because of the dominant role of
fuel sulfur content on exhaust particulate emissions, the test fuels
will hereinafter be identified by their sulfur content such that:
Fuel (1) = 0.019 wt.% S
Fuel (2) = 0.110 wt.% S
Fuel (3) = 0.091 wt.% S
III.3 Catalysts
A total of 9 catalysts were tested. These include 4 monolithic
oxidation catalysts, 3 pelletized oxidation catalysts and 2 NOX reduction
catalysts. The guidelines for catalyst selection were based on the
probability of its commercial use in the near future and availability.
The following monolithic oxidation catalysts were tested:
(1) Engelhard PTX-IIB, hereinafter referred to as Engelhard Monolith.
(2) Two Universal Oil Products catalysts having ostensibly similar
properties hereinafter referred to as UOP(l) and UOP<2) respectively.
(3) Matthey Bishop - hereinafter referred to as the Matthey Bishop
Monolith.
Three pelletized oxidation catalysts were tested.
(1) Engelhard pelletized catalyst - hereinafter referred to as Engelhard
Pellet.
(2) Grace pelletized catalyst - hereinafter referred to as Grace Pellet.
(3) Air Products pelletized catalyst - hereinafter referred to as
Air Products Pellet.
-------
- 28 -
Table III-l
ASTM Research Octane
ASTM Motor Octane
Lead (gms/gal)
Weight % Sulfur
FIA Analysis
% Aromatics
% Olefins
% Saturates
ASTM, Gum (mg/100 ml)
RVP (psi)
API Gravity @ 60°F
ASTM Distillation (D86)
IBP
5% Overhead at °F
10%
20%
30%
40%
50%
60%
70%
80%
90%
FBP
% Loss/% Bottoms
:ations of
Break
in
Fuel
95.5
85.9
0.052
0.006
29.6
5.8
64.6
0.4
8.32
61.1
94
120
131
149
168
190
212
229
247
271
313
383
0.4/1.4
Fuels Used
Fuel
(1)
93.0
84.6
<0.01
0.019
21.3
6.4
72.3
0.0
9.4
60.5
92
115
125
143
162
183
206
223
236
251
291
386
1.0/1.5
Designation
(2)
92.6
83.4
0.063
0.110
25.1
8.5
66.4
0.0
8.58
59.6
95
117
128
149
165
190
214
233
250
274
314
365
0.9/1.3
(3)
98.8
86.5
0.056
0.091
45.8
7.1
47.0
4.4
8.64
52.2
100
125
138
160
177
203
222
248
266
297
340
4.2
2.0/1.0
-------
- 29 -
The two NO reduction catalyst systems were:
(1) Grace NOX reduction catalyst - hereinafter referred to as Grace
Reduction.
(2) GEM 68 catalyst made by Gould Inc. - hereinafter referred to as Gould
Reduction.
The model and serial numbers of these systems where available
are given in Table III-2 below.
Table III-2
Model and Serial Numbers of Catalysts Tested
Catalyst
Engelhard Monolith
UOP(l)
UOP(2)
Matthey Bishop Monolith
Engelhard Pellet
Grace Pellet
Air Products Pellet
Grace Reduction
Gould Reduction
Model
Number
513
7471-210
7471-529
8026
260
Serial
Number
407 7011
7-2916
HN 2428
III.4 Test Procedure
As discussed in the introduction section of this report,
the test procedure consisted of operating a catalyst equipped vehicle
through five separate modes: an initial 1975 FTP, followed by a
one-hour idle, a one-hour 64 km/hr (40 mph) cruise, a two-hour 112
km/hr (70 mph) or two-hour 96 km/hr (60 mph) cruise. This was
followed by an overnight cooling and a final 1975 FTP. The one-hour
idle, and the two cruise modes were all hot start tests. No attempts
to cool down between these tests were made.
Fresh, pre-weighed glass fiber filters were used in each test
run to collect particulate for total particulate determination. A
fresh (unweighed) Millipore filter was used in each run to collect
particulate for metals analyses. Gaseous emission rates were determined
in each test run for hydrocarbon, carbon monoxide, NO and SO^ in
diluted exhaust.
III.4.1 Gaseous Emissions
Since the exhaust particulate sampler is compatible with the
CVS unit, simultaneous gaseous and particulate emission rates could be
measured on each test mode. Carbon monoxide was analyzed using an
NDIR analyzer, hydrocarbons by FID, NOX by chemiluminescence and S02
by pulsed UV fluorescence. The measurement technique for S02 is
discussed in detail in Section A.2 of Appendix A. The detailed gaseous
emission rates are given In Appendix E.
-------
- 30 -
III.4.2 Particulate Sampling Procedures
Four parallel filter samples were taken during each of the
five test modes. These were as follows:
(a) Two 142 mm diameter Gelman Type A fiber glass filters coupled to
probes sampling at 15 SCFM. These samples were used to check
internal agreement and allow the determination of total particulate
emission rates, sulfate emission rates, and for analyses of water,
carbon, nitrogen, non-sulfate sulfur, and platinum. The analytical
procedures for sulfate, water, carbon, etc., are discussed in
Appendix A.
(b) One 90 mm diameter Millipore ashless filter coupled to a probe
sampling at 5 SCFM. This filter sample was used for determination of
the emission rates of Ca, Al, Zn, Cr, Fe, Cu, Ni, and Pb. All of
these metals were determined by emission spectroscopy. This
analytical technique and its adaption for measuring vehicular
metallic emission rates is discussed in Section A.4 of Appendix A.
(c) A 1.5 SCFM sample for particulate size determination with an Andersen
Particle Sizing Sampler. This sampler was modified to determine
particle size distribution by weight. The use of the modified
sampler is discussed in Appendix B.
The Exhaust Particulate Sampler is designed to collect particulate
emissions at constant temperature (32°C) during the FTP or 64 km/hr (40
mph) steady state cruise. However, the system was not designed to have
the capability of handling the heat load generated by 96 km/hr (60 mph)
and 113 km/hr (70 mph) cruise conditions. In order to maintain tempera-
ture control at the high speed cruise conditions, attempts were made to use
a raw exhaust flow splitter. The function of this splitter was to reduce
the heat load on the sampling system by venting a known constant fraction
of raw exhaust prior to injection of the exhaust into the flow development
tunnel. The splitter was designed to reject 75% of the raw exhaust.
Experiments with ambient air substituting for raw exhaust
showed that the splitter worked as intended. However, the raw exhaust
from an oxidation catalyst equipped vehicle corroded the velocity sensing
elements of the device so that it was inoperable. The experiments with
the exhaust splitter are described in Appendix C.
Consequently, the high speed cruise runs were carried out
with the entire exhaust injected into the tunnel, which meant that particulate
was not collected at constant temperature for these runs. This means
that during the high speed cruises, deviations from isokinetic sampling
occur. The error created by non-isokinetic (or anisokinetic) sampling
has been studied by several investigators(2). For fine particles, less
-------
- 31 -
than 10 microns equivalent diameter, the error introduced by deviations
from isokinetic sampling that are less than 20% are negligible. For
coarse particles (greater than 50 microns equivalent diameter), the error
in measuring particulate approximates the deviation from isokinetic
sampling(26) The Environmental Protection Agency(27) has suggested
that for deviations from isokinetic sampling of less than 20%, particulate
mass be corrected by the equation
M - I MS (1 + VV)
where M = the actual mass of particulate
MS = the mass of particulates in the sample
Vs = volumetric flow rate of the sample
V = volumetric flow rate of an isokinetic sample
The above equation indicates that the error in measuring the
particulate mass will be half the deviation from isokinetic sample
regardless of whether the sampling is supra or subisokinetic.
In the high speed cruises without temperature control, the
deviation from isokinetic sampling through most of the run is below 10%
so that the error in measuring the particulate mass is below 5%. This
is the error caused in sampling particulate matter present in a stream
above 32°C (90°F).
Another source of error caused by temperature excursions, above
32°C is that organic matter that exists as particulate at that tempera-
ture and consequently is collected on the filters may not exist as
particulate at the higher temperatures. This would apply to some of the
organic components that would exist as particulate matter. There is no
way of evaluating the error from this temperature effect, although it
is probably small because of the following reason. The lean carburetion
on both vehicles reduces not only the gaseous emissions but also the
organic exhaust particulate components. These vehicles are also
equipped with air pumps and exhaust manifold air injection to further
decrease hydrocarbon and CO emissions by reaction of the oxygen in the
air with the hot exhaust gases. At the high raw exhaust temperatures,
air injection also reduces the gaseous organic precursors of organic
particulate. Thus, the formation of organic particulate emission rate
of a conventional 1974 GM vehicle should be considerably below that
exhibitied by earlier vehicle models. Springer(28) presents evidence
that with a 1970 Chevrolet CID V-8, the total particulate emission rate
is very sensitive to temperature below 20QOF. Based on Springer's
data, it is estimated that at the maximum of the temperature excursion
during the high speed cruise, the decrease in collected particulate
would be approximately 16%. However, since it takes a finite time
interval to approach the higher temperatures, the run averaged
temperature effect on particulate losses should be below 16%.
-------
- 32 -
It would also be expected that with the leaner operation of
a 1974 vehicle coupled with air injection, only the less volatile, less
easily oxidized organic precursors would be more likely to survive. The
formation of these precursors into particulate matter would occur at high
temperatures, so that their collection at filters would be less sensitive
to collection temperature. Consequently, it would be expected that with
the vehicles used in this program, the effect of temperature at the particu-
late collection stage on the organic particulate matter collected would be
small enough to be within acceptable limits so that only small errors in
calculated emission rates would result.
When the vehicle is equipped with an oxidation catalyst, the
organic portion of the exhaust particulate is extensively reduced about
an 80% reduction relative to pre-control vehicles, with the result
that there is little temperature dependent organic particulate pre-
crusors in the raw exhaust. Consequently, the effect of particulate
collection temperature on organic particulate emissions should be quite
small.
The collection of sulfuric acid aerosol should be independent
of temperature as long as the collection temperature is below sulfuric
acid dew point. Thus, if the collection temperature does not exceed
about 90°C (29,30), all of the acid exists as aerosol. Although the
tunnel residence time is small M).l second), the formation of aerosol
droplets is virtually instantaneous(31). Particulate collection tempera-
tures during the high speed cruises are well below the sulfuric acid
dew point so that all the sulfuric acid exists as aerosol.
The collection of the metallic components in the exhaust
particulate obviously are not temperature dependent so that no error
in the measurement of these species occurs as a result of the tempera-
ture increases incurred during the high speed cruise modes.
-------
- 33 -
IV. RESULTS AND DISCUSSION
IV.1 Sulfur Compounds in Exhaust Emissions
IV.1.1 SO,, in Auto Exhaust
Although the charge of the contract was the characterization
of exhaust particulate matter, the contract specified that 30 S02
measurements should be carried out. Sulfur dioxide determinations
were performed in virtually every run however since this compound is
not only the most predominant sulfur containing gaseous species in
auto exhaust, but because particulate sulfate is derived from exhaust
S02. Thus determination of exhaust 802 coupled with determination
of particulate sulfate allows the determination of the fate of fuel
sulfur, and the attainment or lack of a sulfur material balance allows
one to approximately assess the extent of sulfate storage. The
phenomenon of sulfate storage is discussed in Section IV.1.5.
Sulfur dioxide was measured using the TECO pulsed fluorescence
analyzer discussed in Appendix A.
Although other gaseous sulfur compounds may exist in auto
exhaust, they are not related to particulate sulfur compounds (pre-
dominantly sulfate), and exist in quantities too small to have
appreciable effects on sulfur material balance. The accounting of
fuel sulfur in terms of emitted S0£ and sulfate aerosol is discussed
in Sections IV.1.4.1 and IV.1.4.2.
IV.1.2 Dependence of Total Particulate Emission
Rates on Fuel Sulfur Content
Figure IV.1 shows the total particulate emission rates
obtained on the averaged 1975 FTP's for the base case vehicle,
and with the vehicle equipped with monolithic oxidation catalysts.
It can be seen that with the unequipped vehicle, the total particulate
emission rate is independent of the fuel sulfur content. With the
monolithic oxidation catalysts, the total particulate emission rate
is approximately linearly dependent on the fuel sulfur content.
Similar type of behavior was obtained when the vehicle was
equipped with pallatized oxidation catalyst systems. However, the
total particulate emission rates were lower than that obtained with
monolithic oxidation catalysts, so that a lower order of dependence
of emission rate on fuel sulfur content is observed as shown in
Figure IV.2.
The average of the initial and final 1975 FTP total particulate
emission rates (Figures IV-1 to IV-3) was used as a convenient parameter
to approximately gauge the dependence of these emissions on fuel sulfur
content for the base case and catalyst equipped vehicle. There is no
rigorous basis for choosing this average. This is especially so since
there are cases with both the monolithic and pelleted oxidation catalyst
runs where large differences in the initial and final FTP total particulate
emission rates were obtained, indicating that the vehicle-catalyst com-
bination being tested was not stabilized with respect to particulate
emissions. Sulfate storage in the pelleted oxidation catalyst equipped
vehicle is an additional complicating factor. That the total particulate
-------
I
CO
0.250
tf 0.200
o
H
CO
CO
H
cu
4J
CO
1-4
3
O
H
4J
h
CO
CO
JJ
o
H
0.150
0.100
0.050
- 34 -
FIGURE IV-1
DEPENDENCE OF TOTAL PARTICULATE EMISSION RATES, gms/km
ON FUEL SULFUR CONTENT (AVERAGE OF INITIAL AND FINAL 1975 FTP)
Base Case Vehicle, 4 Monoliths
©
O
= Base Case
= Engelhard
= UOP(l)
= UOP(2)
= Matthey Bishop
0.025
0.050
0.075
0.100
0.125
Fuel Sulfur Content, Wt.%
CO
ft
«t
cu
0'.250
0.200
FIGURE IV-2
DEPENDENCE OF TOTAL PARTICULATE EMISSION RATES, gms/km
ON FUEL SULFUR CONTENT (AVERAGE OF INITIAL AND FINAL 1975 FTP)
o
H
CO
" 0.150
6
Base Case Behicle, 3 Palletized Catalysts
O = Base Case
V = Engelhard
^ = Grace
= Air Products
cu
4J
CO
3
U
s
0.100
0.050
0.025 0.050 0.075 0.100
Fuel Sulfur Content, Wt.%
0.125
-------
- 35 -
emission rates vary linearly with fuel sulfur content with oxidation
catalyst equipped vehicles, Figures IV-1 and IV-2, may be fortuitous, at
least for the FTP test runs. Thus, no theoretical significance should be
attached to the slopes of the lines in Figures IV-1 and IV-2. While total
particulate emission rates may vary linearly with fuel sulfur content with
an oxidation catalyst equipped vehicle over a large variety of conditions,
the case for linearity would best be substantiated with a thoroughly con-
ditioned particulate emission stabilized test vehicle. This would be beyond
the scope of this program. As stated previously, the intention of the plots
in Figures IV-1 and IV-2 is to elicit the approximate dependence of particu-
late emissions and fuel sulfur levels as a function of catalyst type.
By contrast, the total particulate emission rates obtained
when the test vehicle was equipped with NOX reduction catalysts
showed no dependence on fuel sulfur content. As shown in Figure IV.3,
the particulate emission rates with NOX reduction catalysts are
essentially the same as with the base case vehicle.
On the 64 km/hr (40 mph) cruise runs, the total particulate
emission rates with the unequipped vehicle were low and independent
of fuel sulfur content. The total particulate emission rates with
monolithic catalyst equipped vehicles were linearly dependent on fuel
sulfur levels, and were greater than what was exhibited on the
1975 Federal Test Procedures, Figure IV-4. It can be seen that
significant differences in the emission rates are exhibited by the
monolithic systems tested, the UOP catalysts emitting about four
times as much exhaust particulate as the Matthey Bishop catalyst.
Similarly with the pelleted oxidation catalysts, as shown in Figure IV-5,
total particulate emission rates also varied linearly with fuel sulfur
content. The emission rates with the pelleted systems were lower than
those of the monolithic systems, the exception being the monolithic Matthey
Bishop catalyst.
As shown previously in Figure IV-3, the particulate emission
rates of NOX reduction catalyst equipped vehicles were invariant
with respect to fuel sulfur content. This was not the case when the
vehicle equipped with these catalysts was operated at 64 km/hr for
one hour. As shown in Figure IV-6, th£ total particulate emission
rates vary linearly with fuel sulfur content as in the case of the
oxidation catalysts. Total particulate emission rates with the NO
reduction catalysts are lower than what was obtained with any of x
the oxidation catalysts (monolithic or pelleted type).
At the high speed cruises (96 or 113 km/hr), the total
particulate emission rates of the vehicle equipped with the various
monolithic catalysts were linearly proportional to fuel sulfur content,
but were lower than that exhibited by the same catalysts or the same
fuels at the lower vehicle cruise speeds. The relative particulate
emissions of the catalysts is changed in that the second UOP monolith,
which emitted lower levels of particulates than the first UOP monolith
at 64 km/hr vehicle cruise speed, emitted higher level at the
higher speed cruise. Both UOP monolith equipped vehicles emitted
more particulate than when equipped with the Engelhard or Matthey
Bishop monolith. These results are shown in Figure IV-7.
With pelleted oxidation catalysts, deviations from linearity
are observed with the Engelhard and Air Products catalyst systems..
Emission rates obtained with the Grace catalyst equipped vehicle
-------
- 36 -
FIGURE IV-3
1
c
o
r-l
CO
CO
l-l
E
CD
4J
CO
3
u
t-l
CO
Pu
CO
4-1
O
H
DEPENDENCE OF TOTAL PARTICULATE EMISSION RATES, gins/km
ON FUEL SULFUR CONTENT (AVERAGE OF INITIAL AND FINAL 1975 FTP)
0.050
0.040
0.030
0.020
0.010
Base Case Vehicle, Two NO Reduction Catalysts
J_
0.025 0.050 0.075
Fuel Sulfur Content, Wt.%
0.100
0.125
4
i
»
0)
o
H
CO
CO
0)
4J
CO
0.500
0.400
0.300
0.200
p
CO
(X,
"co" 0.100
4J
O
H
FIGURE IV-4
DEPENDENCE OF TOTAL PARTICULATE EMISSION RATES, gins/km
ON FUEL SULFUR CONTENT MONOLITHIC CATALYST EQUIPPED VEHICLE
64 km/hr (40 mph cruise)
O = Base Case
= Engelhard
= uop(i)
= UOP(2)
= Matthey Bishop
0.025 0.050 0.075
Fuel Sulfur Content, Wt.%
0.100
0.125
-------
- 37 -
FIGURE IV-5
DEPENDENCE OF TOTAL PARTICULATE EMISSION RATES, gms/km
ON FUEL SULFUR CONTENT, PELLETIZED CATALYSTS
64 km/hr (40 mph Cruise)
Base Case
Engelhard
Grace
Air Products
0.025 0.050 0.075
Fuel Sulfur Content, Wt.%
0.100
0.125
J
m
§,
0)
4J
2
c
o
H
(0
CO
'e
0)
3 0.100
H
CO
PL.
o
H
0.200 _
0.150 -
0.050 -
FIGURE IV-6
DEPENDENCE OF TOTAL PARTICULATE EMISSION RATES, gms/km
ON FUEL SULFUR CONTENT WITH NO REDUCTION CATALYSTS
64 km/hr (40 mph Cruise
O = Base Case
= Grace
A = Gould
0.025 0.050 0.075
Fuel Sulfur Content, Wt.%
0.100
0.125
-------
- 38 -
FIGURE IV-7
DEPENDENCE OF TOTAL PARTICULATE EMISSION RATES, gins/km
ON FUEL SULFUR CONTENT MONOLITHIC CATALYST EQUIPPED VEHICLE
(96 or 112 km/hr Cruise)
CO
i,
« 0.400
s
c
o
S 0.300
r-l
e
cu
u
5 0.200
u
* 0.100
l-l
CO
4J
o
O = Base Case
= Engelhard
= UOP(l)
Q= UOP(2)
= Matthey Bishop
0.025 0.050 0.075
Fuel Sulfur Content, Wt.%.
0.100
0.125
CO
91
4J
0.400
o
H
CO
g 0.300
w
cu
4J
CO
U
H
4J
0.200
CO
PL.
^ 0.100
FIGURE IV-8
DEPENDENCE OF TOTAL PARTICULATE EMISSION RATES, gins/km
ON FUEL SULFUR CONTENT PELLETED CATALYST EQUIPPED VEHICLE
(96 or 112 km/hr Cruise)
O = Base Case
V = Engelhard
^ = Grace
= Air Products
0.025 0.050 0.075
Fuel Sulfur Content, Wt.%
0.100
0.125
-------
- 39 -
varied linearly with fuel sulfur content. The high speed cruise
results with the pelleted catalyst systems are shown in Figure IV-8.
Figure IV-9 shows that the total particulate emissions varied linearly
with fuel sulfur content at the high speed cruises when the vehicle
was equipped with either the Grace or Gould N0x reduction catalysts.
The dependence of the total particulate emission rates on the
fuel sulfur content is due to the production of sulfate aerosol.
This aerosol is produced in the presence of an oxidation catalyst,
and under certain circumstances in the presence of a NOX reduction
catalyst. The presence of a heterogeneous catalyst is a necessary
requirement. Sulfate production is discussed in the next section. The
detailed data on total particulate emission rates are given in
Appendix E.
IV.1.3 Sulfate Emission Rates
The quantity of soluble sulfate on the total filters was
routinely determined using the titrimetric procedure discussed in
Appendix A. Figure IV-10 shows the sulfate emission rates as a
function of fuel sulfur content obtained on the 1975 FTP for the un-
equipped base case vehicle, and when the vehicle was equipped with
each of the four monolithic oxidation catalysts. The sulfate emission
rates are reasonably linear with fuel sulfur content as in the case
of the total particulate emission rate. The slopes are about half
that obtained on the total particulate plot. These results are
consistent with earlier results(3) in which it was found that the
sulfates emitted from an oxidation catalyst equipped vehicle account
for approximately half the total particulate.
As shown in Figure IV-11 , similar results are obtained with
palletized oxidation catalysts in that the emission rates of sulfate
are approximately linear with fuel sulfur content and account for
about half of the total particulate. The absolute levels of emitted
sulfate for the pelleted catalyst equipped vehicles are generally
lower than those obtained with a monolithic oxidation catalyst
equipped vehicle. The differences exhibited between the monolithic
and pelletized catalyst systems on the 1975 FTP can be attributed
to storage of sulfate on the pelleted systems. Sulfate storage
phenomenon are discussed in Section IV.1.5.
Figures IV-12 and IV-13 depict the sulfate emission dependence
on fuel sulfur content for both monolithic and pelletized catalysts
vehicles for the 64 km/hr cruises. In both cases, the sulfate emission
rates vary linearly with fuel sulfur content. Sulfate emissions from
the base case vehicle are too low to be sensibly plotted on the above
figures.
The wide range of sulfate emissions for a given fuel sulfur
level shown in Figure IV-12 indicates that significant differences
exist between the various monolithic catalysts. For example, the vehicle
equipped with the Matthey Bishop catalyst emitted only about one-fourth
of the sulfate emitted with one of the UOP systems. It should be
realized that only one sample of each catalyst was tested, replicate
testing would be necessary to substantiate the observed differences.
EPA (17), in their own tests, have corroborated the above results so
that there is good reason to believe that the differences observed are
significant. The sulfate emission rates with the pelleted catalysts
are comparable to the Engelhard monolith and the second UOP monolith
tested.
-------
J
CO
i,
3 o.ioo
o
1-1
CO
? 0.075
FIGURE IV-9
DEPENDENCE OF TOTAL PARTICULATE EMISSION RATES, gms/km
ON FUEL SULFUR CONTENT, NOX REDUCTION CATALYST EQUIPPED VEHICLE
(96 km/hr Cruise)
01
4-1
CD
I
3
U
CD
Pu
CD
4J
o
H
0.050
0.025
O = Base Case
A = Grace
= Gould
D 0.025 0.050 0.075 0.100 0.125
Fuel Sulfur Content, Wt.%
FIGURE IV-10
SULFATE EMISSION RATE VS. FUEL SULFUR CONTENT
(AVERAGE OF INITIAL AND FINAL 1975 FTP)
BASE CASE AND MONOLITHIC OXIDATION CATALYST EQUIPPED VEHICLE
J 0.100
J 0.075
-------
- 41 -
J
01
3
CO
0.050
0.040
0.030
c
o
H
CO
-2 0.020
w
0)
0.010
FIGURE IV-11
SULFATE EMISSION RATES VS. FUEL SULFUR CONTENT
(AVERAGE OF INITIAL AND FINAL 1975 FTP)
BASE CASE AND PELLETIZED OXIDATION CATALYSTS
= Base Case
= Engelhard
= Grace
= Air Products
0.025 0.050 0.075
Fuel Sulfur Content, Wt.°
0.100
0.125
0.250
FIGURE IV-12
DEPENDENCE OF SULFATE EMISSION RATES, gms/km ON FUEL
SULFUR CONTENT MONOLITHIC CATALYST EQUIPPED VEHICLE
64 tan/hr (40 mph Cruise)
J 0.200
01
a
CO
« 0.150
§
f-l
CO
e
u
V
4J
10
CO
0.100
0.050
= Base Case
= Engelhard
= UOP(l)
= UOP(2)
= Matthey Bishop
0.025 0.050 0.075
Fuel Sulfur Content, Wt.%
0.100
0.125
-------
FIGURE IV- 13
DEPENDENCE OF SULFATE EMISSION RATES, gros/km
ON FUEL SULFUR CONTENT PELLETIZED CATALYST EQUIPPED VEHICLE
64 km/hr (40 mph Cruise) _
0>
01
01
c
o
H
CO
03
i-l
0)
4J
CO
3
C/3
0.100
0.075
0.050
0.025
Base Case
Engelhard
Grace
Air Products
0.025 0.050 0.075
Fuel Sulfur Content, Wt.%
0.100
0.125
CO
o>
4J
CO
CO
1
o>
4J
CO
0.125
0.100 _
0.075
0.050
0.025
FIGURE IV-14
SULFATE EMISSION RATES VS. FUEL SULFUR CONTENT
BASE CASE AND MONOLITHIC OXIDATION CATALYSTS
(96 or 113 km/hr Cruises)
= Base Case
= Engelhard
- UOP(l)
= UOP(2)
= Matthey Bishop
0.025
0.050 0.075
Fuel Sulfur Content, Wt.%
0.100
0.125
-------
- 43 -
At the higher cruise speeds 96 or 113 km/hr (60 or 70 mph),
the sulfate emissions from the monolithic oxidation catalyst equipped
vehicles were essentially linear with fuel sulfur content. These
results are shown in Figure IV-14. The second UOP system emitted
higher levels of sulfates than did the first one, the reverse of the
emission rates at the lower cruise speeds. One possible reason for this
type of reversal in relative emission rates is that the vehicle speed
when the second UOP catalyst was tested was 96 km/hr as opposed to 113
km/hr for the first system. Again, the sulfate emission rates with the
base case vehicle are too low to be sensibly plotted on the figures below.
Basically similar results were obtained with the pelletized
oxidation catalysts, Figure IV-15. The results are shown as straight
lines although there are apparent departures from linearity. At the
high speed cruises, the sulfate emission rates observed with these
catalysts are comparable to those observed with monolithic catalysts.
This indicates that sulfate storage on the pelletized catalyst system
is not a major factor during high speed cruise. Consequently, under
these conditions, both types of catalysts exhibit equivalent sulfate
emission rates.
The total particulate emission rate when the vehicle was
equipped with NOX reduction catalysts did not depend on the fuel sul-
fur content on the 1975 FTP. In fact, as was previously shown in
Figure IV-3, the total particulate emission rates obtained with these
catalysts on the 1975 FTP was indistinguishable from the base case
vehicle emission rates. This was the case because under FTP conditions,
the levels of sulfate emitted were comparable to that emitted by the
unequipped test vehicle, Table IV-1.
Table IV-1
Average Sulfate Emission Rates (Initial and Final
1975 FTP) from NOX Reduction Catalyst Equipped
Vehicle, and Base Case Vehicle
NOX Reduction Fuel Sulfur Sulfate Emission Rate,
Catalyst Wt.% gins/km
None 0.019 0.002
None 0.091 0.002
None 0.110 0.002
Grace 0.019 0.002
Grace 0.091 <0.001
Grace 0.110 0.004
Gould 0.019 0.001
Gould 0.091 <0.001
Gould 0.110 <0.002
On the steady state cruises however, the total particulate
emission rates with the NOX reduction catalyst equipped test car were
linearly dependent on fuel sulfur content as previously depicted in
Figures IV-6 and IV-9. This dependence on fuel sulfur content was
due to production of sulfate under the lean operating conditions
of the cruise test runs. Figures IV-16 and IV-17 show the sulfate
emission rates with both NOX reduction catalysts as a function of fuel
sulfur content.
-------
FIGURE IV- 15
CO
I,
e
o
B,
03
-------
- 45 -
FIGURE IV-17
DEPENDENCE OF SULFATE EMISSION RATES, gms/km
ON FUEL SULFUR CONTENT, VEHICLE EQUIPPED WITH NO REDUCTION CATALYSTS
96 km/hr (60 mph)Cruise X
J
0.050
0.040
0.030
§
H
e
u
0.020
«S o.oio
1-1
3
CO
O = Base Case
= Grace
= Gould
0.025
0.050
0.075
0.100
0.125
Fuel ,Sulfur Content, Wt.%
-------
- 46 -
Subsequent air/fuel ratio measurements showed that even with
the Exhaust Gas Recycle system removed, the vehicle operated much of
the time at near stoichiometric and net lean conditions. It is assumed
that the emitted sulfate was catalytically produced under lean operating
conditions during the cruise test modes. Although the vehicle went net
lean during the acceleration portions of the FTP, the duration of the
lean operating regime is apparently too transient to produce significant
quantities of sulfates.
IV.1.4 Exhaust Sulfur Material Balance
The predominant sulfur compounds in vehicular exhaust are
S02 and sulfate particulate. Consequently, the fate of fuel sulfur
could be adequately determined by an accounting of these two exhaust
components. Figures IV-18 to IV-26 show the S02 and sulfate measurements
for all catalyst/fuel combinations in terms of the fraction of gasoline
sulfur accounted for by the sum of SO2 and sulfate. The detailed data
are presented in Appendix E.
Figure IV-18 shows the S02 and sulfate emissions for the
monolithic catalysts for FTP conditions, Figure IV-19 for the 64 km/hr
cruise; and Figure IV-20 for the 96 and/or 113 km/hr cruise. Figure IV-21
shows the S02 and sulfate emissions for the pallatized catalysts for FTP
conditions, Figure IV-22 for the 64 km/hr cruise; and Figure IV-23 for
the 96 and/or 113 km/hr cruise. Figure IV-24 shows the S02 and sulfate
emissions for the NOX reduction catalysts for FTP conditions, Figure
IV-25 for the 64 km/hr cruise; and Figure IV-26 for the 96 km/hr cruise.
IV.1.4.1 Sulfur Material Balance With
Monolithic Catalysts
Figure IV-18 shows the average total sulfur emissions for
the four monolithic catalysts under 1975 FTP conditions. The shaded
bars represent the percentage of the total sulfur consumed in the
engine emitted as sulfate, the clear bars the percent of fuel sulfur
emitted as SC^. With the exception of the Matthey Bishop monolith
system, the exhaust sulfur material balance is poor. Much of the
fuel sulfur cannot be accounted for in exhaust either as gaseous or
particulate components.
The lack of a sulfur material balance is attributed to sul-
fate storage on the catalyst-substrate system. When conversions of
exhaust S02 is low, adequate sulfur material balances can be obtained.
For example, earlier work on conventional vehicles in which conversions
to sulfate were less than one percent showed that the fuel sulfur could
be quantitatively accounted for predominantly as 502(18). It may be
inferred therefore that the Matthey Bishop oxidation catalyst is
less active for S02 conversion than the other monoliths based on the
higher S02 emission rates observed with that system which was almost
-------
FIGURE IV-18
S0n AND SULFATE EMISSIONS FOR MONOLITHIC CATALYSTS FOR THE 1975 FTP
or Sulfate
>-
o
o
- 90
00
to
^ 80
OJ
JJ
-U
1 70
i-i
3
LO
0)
5 50
D
V)
to
« ^
0
30
20
10
0
Mat they Bishop
-
.
Engelhard
-
*
uj^"i
1
5****
__
^
§£
UOP(l)
ST^i
$>?
wMta
ABC ABC AEC
Fuel
= S02
B&i = Sulfate
* S0? not found
uop(2) Fuel Sulfur Content
^M
^Ov
\A-A
'W
)OC
1
A = 0.019%
B = 0.110
C = 0.091
ABC
-------
FIGURE IV-19
SO,. AND SULFATE EMISSIONS FOR MONOLITHIC CATALYSTS AT 64 gm/km CRUISE
0)
Jj 100
r-l
3
C/3
CM
O
H
B
90
80
70
60
to
2 50
H
;H
O
S 40
o
30
20
10
Engelhard
XX ^\,
%«
^
^
ABC
Matthey Bishop
ABC
UOP(l)
ABC
UOP(2)
ABC
n
= so*
= Sulfate
* S02 not found
Fuel Sulfur Content
A = 0.019%
B = 0.110
C = 0.091
oo
I
Fuel
-------
FIGURE IV-20
L AND SULFATE EMISSIONS FOR MONOLITHIC CATALYSTS AT 96-113 km/hr CRUISE
01
CO
£ 10°
CM
O
to
O
m
80
70
60
50
30
20
10
MONO (I)
AB
MONO (II)
ABC
MONO (III)-2
MONO (III)-l
A B C
ABC
= so.
=Sulfate
A S02 not found
** S02 not measured
Fuel Sulfur Content
A = 0.019%
B = C.110
G = 0.091
VO
I
Fuel
-------
FIGURE IV-21
SO AND SULFATE EMISSIONS FOR PELLETED CATALYSTS FOR THE 1975 FTP
-------
FIGURE IV-22
S0n AND SULFATE EMISSIONS FOR PELLETED CATALYSTS AT 64 km/hr CRUISE
-------
FIGURE IV-23
SO,, AND SULFATE EMISSIONS FOR PELLETED CATALYSTS AT 96-113 km/hr CRUISE
kJ W«
<4-l
r-l
3
l-i
0
CN
O
CO
(fl
"^
ti
QJ
H
e
w
H
-*
V5
a
H
0
'.I
O
U-l
C
6-5
100
90
80
70
60
50
40
30
20
10
Grace
Engelhard
Air Products
0 ABC
Fuel
ABC
D.
S02
Sulfate
S02 not found
'<* S02 not measured
Fuel Sulfur Content
A = 0.019%
B = 0.110
C = 0.091
S3
I
-------
FIGURE IV- 24
SO,, AND SULFATE EMISSIONS FOR NO REDUCTION CATALYSTS FOR THE 1975 FTP
Grace
» 100
CO
3
0
CN
8 so
CO
CO
"8 70
4J
I-l
B
w 60
3
1 50
0)
CS
rl
"o 40
en
g 30
B-S
20
10
0
-
^^
Go
^MM
Tnc
uld
I^^^H
= so2
^ = Sulfate
Oi
UI
ABC
ABC
FUEL
-------
FIGURE IV-25
S02 AND SULFATE EMISSIONS FOR NOX REDUCTION
CATALYSTS AT 64 km/hr CRUISE
100
0)
jj
(U
3
co
CM
O
CO
eg
T3
-------
FIGURE IV-26
S02 AND SULFATE EMISSIONS FOR NOX REDUCTION
CATALYSTS AT 96 km/hr CRUISE
Gould
100
0>
Q
"3 90
C/l
I,
H
o
CM 80
o
to
ft
" 70
13
0)
1J
JJ
6 60
w
3
:j 50
0)
c
3 40
o
CO
3
30
ii 1
0
20
10
0 .
Grace
.
_
_
.
-
-
-
-
-
^M^
S2
*
28
\Af
v$
W
»
£&<
W
= so.
2
^
^
M^^
1
«8
ys/y
^X8 = Sulfate
* - malfunction at CVS,
S02 reading uncertain
FUEL
ABC
ABC
-------
- 56 -
sufficient in itself to account for the fuel sulfur. Although the
emitted sulfate levels obtained on the FTP with the UOP(l) catalyst
system were comparable to that obtained with the Matthey Bishop
catalyst, the S02 emission rates were considerably lower. This
indicates that the extent of conversion of S02 to sulfate is greater
with the UOP(l) catalyst but that an appreciable portion of the
sulfate made does not show up in the emitted exhaust.
This is substantiated by the similar behavior on the 64
km/hr (40 mph) cruises. Again, the total sulfur balance for the
Matthey Bishop catalyst is nearly 100%, while the other monolithic
catalysts on the average account for 55 to 75% of the fuel sulfur
consumed. The sulfate yields from the Matthey Bishop catalyst are
considerably lower ^15%) than the other monoliths which averaged
about 36% and ranged from 12 to 53%.
On the high speed cruises (96-113 km/hr), the sulfate emis-
sion rates with the Matthey Bishop system were comparable to that of
the Engelhard and UOP(l) monoliths. However, the S02 emission rates
with the Matthey Bishop system were higher than that observed with
the other catalysts and again, a better sulfur material balance was
obtained. These results indicate that although the sulfate emission
rates of the catalyst systems discussed above are comparable, the
actual S02 conversions may be considerably different.
Although the two UOP catalysts exhibited similar behavior
on the lower cruise speed test mode (in terms of S02 and sulfate emis-
sions), at the higher cruise speeds, the UOP(2) system exhibited essen-
tially the same S02 emission rates, but higher sulfate emission rates
than the UOP(l) monolith.
IV.1.4.2 Sulfur Material Balance With
Pelletized Catalysts
As shown in Figures IV-21 to IV-23 still greater deficiencies
in sulfur balances are obtained with palletized catalyst systems. On
the FTP, Figure IV-21, only 20-35% of the total fuel sulfur is
accounted for, the Engelhard and Grace catalysts emitting about 4% of
the fuel sulfur as sulfate, the Air Products System emitting about
10% of the fuel sulfur as sulfate.
Similar behavior is exhibited on the 64 km/hr (40 mph) cruises.
The sulfur material balance deficiencies obtained with the pelletized
systems are greater than that obtained on their monolithic counterparts.
Thirty to 60% of the fuel sulfur was accounted for, with the sulfate
yields ranging from 20 to 30%.
On the 96 or 113 km/hr cruises the sulfur material balance
was generally better than what was obtained on the 1975 FTP's or the
64 km/hr cruises. Sulfate conversions averaged from about 25 to 30%.
The sulfur dioxide accounted from about 39 to 51% of the fuel sulfur,
which is higher than what was obtained on these systems, on either
the FTP or 64 km/hr cruises. The percent, of the fuel sulfur accounted
for (S02 + sulfate) ranged from 63 to
-------
- 57 -
The higher S02 emission rates on the high speed cruises,
indicative of lower SC>2 conversions may be due to the following
factors:
(1) The higher space velocities at the high speed
cruises could result in lower conversions. Bench
scale studies(19) assessing the effect of space
velocity on conversion substantiate this claim.
(2) Because of the unfavorable equilibrium (S02 + 1/2 02 ^ 803),
conversion is less favorable at the higher catalyst
temperatures which would prevail at the high speed
cruises.
The sulfur material balance would be expected to be better
because, in addition to the above, because of the reduced tendency
to store sulfur at the higher cruise speeds (and consequently) higher
catalyst temperatures. Sulfate storage experiments carried out on this
contract program are discussed in Section IV.1.5.
IV.1.4.3 Sulfur Material Balance With
NO Reduction Catalysts
J\ "
Figure IV-24 shows the average total.sulfur emissions for
the two NOX reduction catalysts under 1975 FTP conditions. Average
total sulfur recoveries for both systems was about 97%. Sulfate
emissions amounted to less than 1% conversion. Under FTP conditions,
the sulfur material balance with these catalysts was similar to that
obtained with the unequipped vehicle.
Sulfate emissions increased for both catalyst systems on
both cruise test modes, Figures IV-25 and 26. Conversions based on
emitted sulfates ranged from 4 to 18% on the 64 km/hr cruise. The percent
of total fuel sulfur accounted for in this cruise mode ranged from 72 to
about 82%, higher than that obtained with the vehicle equipped with the
oxidation catalysts. The inability to achieve a complete sulfur balance
apart from experimental error may be due to some sulfate storage
occurring on the NOx reduction catalyst system.
On the 96 km/hr cruise, the average of the total fuel sulfur
accounted for with both systems was 96%. The sulfate emission rates
were generally lower than those measured at lower cruise speeds. Sul-
fate conversions ranged from 1.5 to 15%, averaging about 8 to 9% for
both catalysts over all fuel combinations. The S02 emission rates were
higher on the higher speed cruise mode.
At the two cruise modes both NOx reduction catalysts resembled
the oxidation catalysts in that sulfate particulate was emitted, the
emission rate varying in an approximately linear fashion with fuel
sulfur content (Section IV.1.3). In addition, the lower conversions
at the higher speeds is probably due to the same factors operating to
reduce conversion over the oxidation catalysts, namely the higher
catalyst temperature and space velocity.
-------
- 58 -
The resemblance to oxidation catalysts is due to the
fact that the vehicle in the cruise modes was operating at stoichiometric
and net lean conditions. The Gould catalyst contains a small oxidation
catalyst ahead of the Ni-Cu reduction catalyst in order to extend its
life(20). This oxidation catalyst acts as an exhaust oxygen scavenger.
Under stoichiometric or lean conditions this catalyst would also be
expected to catalyze the oxidation of exhaust S0? to sulfate. Similar
considerations apply to the Grace NOx reduction catalyst, which contains
noble metal and therefore could function as an oxidation catalyst for
S02 under near stoichiometric and net lean conditions (21).
IV.1.5 Sulfate Storage on a Pelletized Catalyst System
Previous studies(3,19) had shown that sulfate can be stored
at under cyclic driving conditions and released under high speed cruise
conditions. To more fully examine sulfate storage the following ex-
periment was carried out. The test vehicle was reequipped with the
Engelhard palletized catalyst that had been previously tested. The
catalyst equipped vehicle was conditioned for 3218 km (2,000 miles)
on the 0.091 wt.% sulfur fuel using the Federal Durability Cycle.
Following conditioning, the vehicle was cold soaked for 24 hours, and
then run through the program test sequence used for screening the
catalysts namely 1975 FTP, one hour idle, 64 km/hr one-hour cruise,
96 km/hr two-hour cruise, an overnight soak, and a final 1975 FTP.
Unlike the screening study in which the conditioning and test fuel
was of the same sulfur content, the test fuel in this case was the
0.019 wt.% sulfur fuel. Conditioning and testing as outlined above makes
it possible to determine whether stored sulfate can be released under
other than high speed cruise conditions.
The CO, hydrocarbon, NOX, SC>2, total particulate, sulfate
and metal emission rates were determined as in the previous screening
studies. Table IV-2 below shows that the hydrocarbon and NOX emissions
are similar in both types of runs (standard vs storage), but that large
differences in CO emissions are obtained.
Table IV-2
Comparison of Gaseous Emission Rates of
Vehicle Equipped with Engelhard Pelletized
Oxidation Catalyst Operated on 0.019 Wt % S Fuel
Emission Rate, gins/km
on 1975 FTP (Initial and Final)
Standard Conditioning Storage Conditioning
CO HC NOy CO HC NOy
2.53 0.22 1.37 1.23 0.19 1.20
2.50 0.22 1.32 1.01 0.19 1.09
-------
- 59 -
The decrease in CO emissions was unexpected and cannot be
satisfactorily explained at present. Although reduction of stored
sulfate by CO can occur, the increase in SC>2 emissions that was ob-
served was not sufficient to account for the decrease in CO emissions.
The increased S02 emissions after storage conditioning will be con-
sidered shortly.
As shown below in Table IV-3, larger differences were ob-
served with respect to SC^, sulfates, and total particulate.
Table IV-3
Emission Rate of Indicated Exhaust
Component, gms/km for Test Runs Fallowing
Standard Conditioning (A), and Storage Conditioning (B)
Test
Type
75 FTP
64 km/hr
96 km/hr
75 FTP
502 H2S04
A
0.015
0.0
0.017
B
0.050
0.016
0.088
0.077
A
0.003
0.001
0.027
0.002
B
0.044
0.119
0.103
0.100
Total
Particulate
A
0.061
0.009
0.115
0.036
B
0.105
0.258
0.239
0.152
The large increase in total particulate emission rates is
due to Increased sulfate emissions as a result of release of stored
sulfate, as shown in Tables IV-4 and IV-5 below.
Table IV-4
Storage Experiments, Palletized
Engelhard Catalyst. 0.019 Wt % S Test Fuel
% Fuel Sulfur Accounted For
As As
Test Sulfate SO, Total
75 FTP 50 83 133
64 km/hr 191 38 229
96 km/hr 157 200 357
75 FTP 105 126 231
-------
- 60 -
Table IV-5
Standard Screening Tests, Pelletized
Engelhard Catalyst, 0.019 wt.% Test Fuel
% Fuel Sulfur Accounted For
As As
Test Sulfate SP_2 Total
75 FTP 3.2 24.2 27.4
64 km/hr 1.5 0.0 1.5
96 km/hr 24.6 35.5 60.1
75 FTP 2.1 53.3 55.4
The 64 km/hr cruise results are reminiscent of earlier storage
studies(3,19) in that sulfate yields in excess of 100% (based on the
sulfur content of the test fuel and fuel economy are obtained). However,
these storage tests have also shown that sustained storage of sulfate
can result in the following situations:
(1) Sulfate yields exceeding 100% can be obtained on lower
cruise speeds such as 64 km/hr.
(2) Sulfate yields exceeding 100% can be obtained under
cyclic driving conditions.
(3) The total exhaust sulfur out (S02 + sulfate) can
exceed 100% although each component may not.
(4) Sulfur dioxide emissions alone can exceed the theoretical
fuel consumption values as it did in 96 km/hr cruise
and the second 1975 FTP.
Although sulfate yields exceeding theoretical values have
been previously observed, that S02 emissions could also exceed theoretical
fuel consumption values was unexpected. Increased SO emissions could
occur through several routes. Reduction of a portion of the stored sulfate
could occur by the following reaction:
Stored H-SO, + CO => S02 + HO + C0_
If the test fuel is one of low sulfur content, the fraction
of exhaust CO that is oxidized need not be large in order that SO2
yields exceeding 100% can occur. Under these circumstances, the CO
emission rate would be undistinguishable from that obtained in a standard
run.
As mentioned previously, the decrease in CO emissions is too
great to account for the increased S02 emission. A decrease in CO emission
rate from 2.5 to 1.0 gms/km by reduction of stored sulfate would result in
an increase in S02 emissions of 3.4 gms/km. This is far in excess of the
total S02 emission rates observed even with S02 yields as high as 200%.
Another possible mechanism operating to produce greater than
100% yields of S02 is the catalytic decoirnnsitron of some of the stored
sulfate as shown below:
-------
- 61 -
S02 + 1/2 02
(stored)
It would not be possible to decide which mechanism or if both were
operating to produce S02 emissions exceeding theoretical based on how
the storage tests were conducted. Separate experiments would be required
to determine the mechanism of increased SO2 production, which were not
called for in the contract.
IV.1.6 Bound Water in Exhaust Particulate
Previous work(3) had shown that the water content of exhaust
particulate increases with increasing sulfate content, but that the
ratio of water to sulfate was relatively constant. Moreover this ratio
corresponds approximately to what would be expected from the equilibrium
% composition-relative humidity relationship at conditions under which the
water analysis took place. This relationship at 20°C is depicted in
Figure IV-27.
As shown in Figure II-6 Section II.2.5, the average relative
humidity at the filter during cyclic test conditions is about 20% at
90°F. This corresponds to 28% relative humidity at room temperature.
The particulate filter is conditioned and weighed in a constant tempera-
ture humidity room (about 45% RH).
It can be seen from Figure 11-27 that a change from 28% rela-
tive humidity to 45% relative humidity results in minor increase in the
weight fraction of water. Thus the weight of particulate should when
sulfuric acid present correspond closely to the quantity collected
on the filter during a run. The relative humidity of the analytical
laboratory although not maintained constant, is probably close to that
in the weighing room, which means that the quantity of water measured
by the Karl Fisher method is a reliable measure of the quantity of bound
water collected on the particulate filters during a test run. Table IV-6
below shows the quantities of bound water in terms of emission rates as
determined by Karl Fisher titration for the base case vehicle and
several catalyst runs on the 1975 FTP.
Table IV-6
Relation of Bound Water to Sulfate Emissions
Emission Rate, gins/km
on 1975 FTP
Run % Fuel Total
No. Sulfur Catalyst Particulate H.SO. H^O
~~~ ' ~~ ~ e. H L
20 0.019 None 0.019 0.001 <0.001
46 0.091 Engelhard Monolith 0.226 0.087 0.092
61 0.091 Engelhard Pellet 0.062 0.016 0.013
75 0.110 UOP(l) 0.090 0.027 0.022
106 0.091 Grace Reduction 0.019 0.001 <0.001
121 0.091 Gould Reduction 0.031 0.001 <0.001
135 0.110 Grace Pellet 0.065 0.034 0.029
151 0.091 UOP(2) 0.173 0.078 0.085
-------
- 62 -
FIGURE IV-27
EQUILIBRIUM % COMPOSITION - RELATIVE
HUMIDITY CURVE FOR AQUEOUS HSO/ AT 2QQC
c
o
100
o
co
o
CO
CM
sc
c
H
O
75
50
&
H
0)
25
0
0
25 50 75
Relative Humidity, %
100
-------
- 63 -
It can be seen that the emission rates of water and HoSO* are comparable
and are fairly close to the equilibrium curve shown in Figure IV-27.
Differences from equilibrium could be due to experimental
errors in the various analytical determinations. Another reason
for the differences is that not all the sulfate (which is what is deter-
mined by analysis) is present as the free acid, but as rather a portion
may exist as metal sulfates. The latter would be unresponsive to
environmental relative humidity conditions. The distribution of sul-
fate could be ascertained by the difference between sulfate determined
by the titrimetric procedure and by titration with base. Although the
acid-base titrations were not performed, it may be readily inferred
from the close approach to the equilibrium % composition-relative
humidity curve that free sulfuric acid is the preponderant sulfate
exhaust particulate component. Earlier work(3) has shown that similar
considerations would apply to steady state cruises.
IV.1.7 Morphology of Automotive Sulfate Particulate
The morphology of the sulfate deposits on the glass fiber
exhaust particulate filters provides direct visual evidence that the
free acid is the predominant form of sulfate particulate emitted by
oxidation catalyst equipped vehicles. Figure IV-28 shows an electron
micrograph of a glass fiber filter from a test with a conventional
vehicle in which little sulfate was produced. This filter was used
as the last stage of the Andersen Impactor and consequently contains
little if any organic particulate matter.
Figure IV-29 is a micrograph of a total filter from a run
with an oxidation catalyst equipped vehicle. This filter contained
125 mg of sulfate. The presence of the free acid can be seen by
the globular deposits on many of the glass fibers and web-like films
that wet many of the fibers. It will be noted that no crystalline
particulate matter appears to be collected on the filter indicating that
little if any sulfate salts are present. Globular droplets, and wetting
of fibers are phenomenon that can only be associated with liquids,
providing further evidence that automotive sulfate exists predominantly
as the free acid.
It is also of interest to note that the parallel lines running
through the micrograph in Figure IV-28 are absent in Figure IV-29.
These lines are image distortions due to the presence of static charges.
They are absent from the micrograph shown in Figure IV-29 because the
sulfuric acid is conductive and can dissipate the static charge. Thus,
the process of obtaining an electron micrograph itself provides evidence
of the presence of free sulfuric acid.
-------
- 64 -
Figure IV-28
Scanning Electron Micrograph of
Absolute Filter From Andersen Impactor
l.OOOX 1 MM = 1 MICRON
10 MICRONS
* ;'. >^ - - - ^
fw.- ''',// '*& «: " "Lr'j'gli^
^%^^p
.;','. -. -jV ' ..v -7^.
- ^' , «!"/ ." iSx^ v» 'J^'1
Figure IV-29
Scanning Electron Micrograph of Total
Filter Containing 125 mg of Sulfate
1000X, 1 MM = 1 MICRON
= 10 MICRONS
.
-------
- 65 -
IV.1.8 Non-Sulfate Sulfur Exhaust Particulate
Chemical spot tests were carried out on particulate samples
generated from the 1975 FTP and 64 km/hr (AO mph) test runs for non-
sulfate sulfur containing particulate matter. The samples analyzed
included those from runs on the unequipped vehicle, and when the
vehicle was equipped with the various catalysts screened in the test
program.
The extreme sensitivity of many of these tests should allow
detection of low levels of non-sulfate particulate matter. Negative
results establish the maximum emission rate possible based on the
sensitivity of the spot test and the mileage accumulated on the
particular test run. The spot tests used were those listed in
Feigl(22). These are discussed in detail in Appendix A.
The filters were analyzed for the presence of the following
sulfur compounds:
thiocarbonyls
thiols
sulfides
disulfides
isothiocyanates
sulfoxides
sulfinic acids
sulfones
The selection of the above compounds as possible exhaust
components is based on chemical species known to be present in auto
exhaust which could function as precursors to the above compounds or as
reactants involved in their production. The basis of this selection
is discussed in Appendix D.
All tests for the above compounds were negative. Based on
the sample size taken (0.42% of the active filter area), the emission
rates of the above compounds cannot exceed the values listed in
Table IV- 7 below.
Table IV-7
ESTIMATED MAXIMUM EMISSION RATES OF NON-SULFATE SULFUR EXHAUST PARTICULATE
gms/km
Compound Type 1975 FTP 64 km/hr cruise
-4 -4
Thiocarbonyl 8 x 10 2 x 10
Thiols
Sulfides " "
Disulfides " "
Isothiocyanates
Sulfoxides " "
Sulfinic Acids " 3 " _4
Alkyl Sulfonic Acids 1 x 10~ 2.5 x 10
Alkyl Sulfonic Acids " "
-------
- 66 -
In several cases, larger portions of filters were analyzed
for the sulfur compounds listed above. Negative results were also obtained
in these instances. It is quite probable therefore that the emission
rates of these compounds if they exist at all in auto exhaust are
probably several orders of magnitude below those rates listed in Table
IV-8. Limited sample sizes were necessary because of the large number
of different analyses that were made on the particulate filters.
On the basis of the results, it appears that nc significant
quantities of organic sulfur compounds are emitted froir catalysts under
these test conditions.
-------
- 67 -
IV.2 Exhaust Metal Particulate Emission Rates
The emission rates of the following metals were measured on
all of the test runs:
Ca, Al, Zn, Cr, Fe, Cu, Ni, Pb, and Pt.
Although referred to as metals, the above exhaust components with the
possible exception of platinum would not be likely to exist in their
elemental state. Both analytical methods (emission spectroscopy and
X-ray fluorescence) do not distinguish whether the above exist in the
metallic or combined state. The analytical techniques are discussed
in detail in Section A.5 of Appendix A.
It is most likely that the above metals when present In exhaust
exist as oxides, sulfates, or mixed oxy-sulfates. No attempt was made to
determine the types of metallic compounds.
The metal derived particulate emissions will hereinafter be
referred to as metal oxides. This term is used simply for convenience and
to indicate that the metal emissions do not exist as the free metals. It
is not meant to imply that the oxide is the only combined form of the metal.
IV.2.1 Metal Oxide Emissions Under 1975 FTP Conditions
The detailed metal emission data are presented in Appendix E.
Figure IV-30 shows the metal emission rates on the 1975 FTP's calculated
as total metal oxides for the base case vehicle and for the vehicle equipped
with the various catalysts. Both initial and final FTP emission rates
are shown for each fuel sulfur content.
The total metal oxide emission rates are generally higher when the
vehicle is equipped with oxidation catalysts ranging from about 0.0018
to 0.0110 gms/km on the 1975 FTP. Metal oxide emissions from the NOX
reduction catalysts ranged from about 0.0019 to 0.0064 gms/km. The
lowest metal oxide emissions were observed with the base case vehicle.
The range in this case was from 0.0002 to 0.0033 gms/km. There does
not appear to be any dependence of metal oxide emission rate with fuel
sulfur level (or correspondingly sulfate emissions), whether the vehicle
is tested in the conventional mode, or equipped either with oxidation
or reduction catalysts on the 1975 FTP.
The increased metal oxide emissions from catalyst vehicles
can probably be associated with attrition from the catalyst system.
The differences exhibited between oxidation catalysts and NOX reduction
catalysts may be due to attrition being greater under the leaner conditions
(higher oxidation potential) that would prevail with these systems.
-------
FIGURE IV-30
TOTAL METAL OXIDE EMISSION RATES, gms/km OBTAINED WITH INDICATED CATALYST,
INITLAL AND FINAL 1975 FTP ON EACH TEST FUEL; ( = INITIAL, = FINAL FTP)
> = 0.019% S. O= 0.110% S. = 0.091% S
en
a
x
o
I
«
u
01
u
u
0.0100
0.0090
0.0080 .
0.0070 .
0.0060
0.0050
0.0040
0.0030 |-
0.0020
0.0010J- '
Base
Case
A
0-1
No
Catalv-, t
Engelhard UOP(l)
Monolith Monolith
UOP(2)
Monolith
O-l
Mat they
Bishop ^ngelhard. Grace
Monolith
O-l
Pellet
Pellet
Air
Products
Pellet Grace
Gould
00
I
Oxidation Catalvsts
NO Reduction
" X ~
4 ts
-------
- 69 -
IV.2.2 Metal Oxide Emissions Under Cruise
Conditions, Relation to Sulfate Emissions
As sulfate emissions were higher on the 64 km/hr. and 96 km/hr.
cruises, it was of interest to see if the metal oxide emission rates could
be correlated with sulfate emissions (fuel sulfur content). Figures IV-31
to IV-39 show the total metal oxide emission rates as a function of fuel
sulfur content for the 64 and 96 km/hr. cruises. The sum of the metal
particulates are usually less than 5 to 10% of the sulfate emissions.
Generally, the sum of the metal emission rates on a given run with
an oxidation catalyst vehicle are a small fraction of the sulfate emissions.
However, on the FTP's with the 0.019 wt.% sulfur fuel, the metal emission
rates exceeded the sulfate emission rates. This is primarily due to the
fact, as discussed above, that metal oxide emissions are higher on the FTP's
than on steady state cruises. When this phenomenon is coupled with the fact
that sulfate storage is more favorable on the FTP than on the steady state
cruises, it is not surprising that the metal oxide emission rates, however
low, could exceed the H2S04 emission rates when an oxidation catalyst equipped
vehicle is operating on a low sulfur fuel under cyclic driving conditions.
Table IV-8 shows the relative emission rates of metal oxide to sulfates for
the vehicle equipped with the various ocidation catalysts on the cyclic and
steady state cruises, operated on the three test fuels. The FTP values are
the averages of the initial and final FTP's of the test sequence.
There does not appear to be any direct relationship between
fuel sulfur content and metal oxide emissions. Indeed, with the exception
of the Air Products pelleted oxidation catalyst (Figure IV-37), the
metal oxide emissions from the vehicle operating on the low sulfur fuel
are generally higher or comparable to those observed when a high sulfur
test fuel is used. These results should not be taken to, mean that some
type of inverse relationship exists between metal oxide emissions and
sulfate emissions (related linearly to fuel sulfur content), but rather
that other factors are operating. No systematic assessment of these factors
was made. However, tentative conclusions may be drawn regarding the Influence
of some of the variables encountered on metal oxide emission rates.
For example, the metal oxide emission rates are generally
higher on the 1975 FTP's than on the steady state cruises. This applies
to both the initial and final FTP's,indicating that accelerations and
decelerations are the major factors responsible for the production of
these types of emissions.
With several exceptions, the emission rates on the first FTP
were higher than the final FTP. This may be due to purging of the
exhaust by the first FTP, idle, and cruise tests prior to the
final FTP. Assuming that purging is responsible for the lower emission
rates obtained on the final FTP, the fact that the FTP emission rates
generally are higher than the steady state cruise emission rates supports
the hypothesis that accelerations and decelerations are the most important
factors influencing metallic particulate emissions.
IV.2.3 Emission Rates of Specific Metals
Analyses for specific metals were carried out in order to
determine how the presence of catalysts alters the emission pattern of
metal-derived particulate. The effect of the catalyst on metal-derived
particulate matter can occur by way of catalyst, substrate attrition,
or both, and/or by reaction between catalytically produced exhaust
components and the exhaust system. For example, catalytically produced
sulfuric acid could react with the walls of the exhaust system, with
some of the surface reaction products then becoming entrained in the
-------
- 70 -
CO
oo
en
c
o
H
CO
CO
H
-------
in
6
00
CO
e
o
H
[0
CO
-------
0.005
- 72 -
FIGURE IV-35
METAL OXIDE EMISSION RATES, gms/km VS.
FUEL SULFUR, WT.% ON STEADY STATE CRUISES
Engelhard Pellet
0.004
CO
00
in
c
o
1-1
en
en
a
w
0)
TJ
H
X
o
0)
J-l
-------
- 73 -
in
c
o
l-l
U)
in
w
0)
o
H
0.00020
0.00150
g 0.00100
0.00005
0
FIGURE IV-37
METAL OXIDE EMISSION RATES, gin/km VS.
FUEL SULFUR. WT.% ON STEADY STATE CRUISES
Air Products Pellet
= 64 kra/hr
O = 96 km/hr
J_
_L
0.025
0.050
0.075
0.100
0.125
I
0.00050
0.00040
oo
at
o 0.00030
rl
co
in
a
w
cu 0.00020
"O
s
o
"« 0.00010
FIGURE IV-38
METAL OXIDE EMISSION RATES, gms/km VS.
FUEL SULFUR. WT.% ON STEADY STATE CRUISES
Grace NO Reduction Catalyst
64 km/hr
96 km/hr
l
I
0.025
0.050 0.075
Fuel Sulfur, Wt.%
0.100
0.125
-------
0.00025
- 74 -
FIGURE IV-39
METAL OXIDE EMISSION RATES, gms/km VS.
FUEL SULFUR. WT.% ON STEADY STATE CRUISES
0.00100
Gould NO Reduction Catalyst
64 km/hr cruise
96 km/hr cruise
0.00075
,o o-
0.00050
0
JL
_L
-L
0.025
0.050 0.075
Fuel Sulfur, Wt.%.
0.100
0.125
-------
- 75 -
Table IV-8
Relative Emission Rates, Total Metal Oxides
To Sulfates for Oxidation Catalyst Equipped Vehicles
Catalyst
Total Metal Oxide Emissions as % of
Sulfate Emissions on Indicated Vehicle Test
% Fuel
Sulfur
Engelhard Monolith
Engelhard Monolith
Engelhard Monolith
UOP (1)
UOP (1)
UOP (1)
UOP (2)
UOP (2)
UOP (2)
Matthey Bishop
Matthey Bishop
Matthey Bishop
Engelhard Pellet
Engelhard Pellet
Engelhard Pellet
Grace Pellet
Grace Pellet
Grace Pellet
Air Products Pellet
Air Products Pellet
Air Products Pellet
0.019
0.110
0.091
0.019
0.110
0.091
0.019
0.110
0.091
0.019
0.110
0.091
0.019
0.110
0.091
0.019
0.110
0.091
0.019
0.110
0.091
75 FTP
212
10
8
367
10
25
88
13
7
367
19
11
325
55
63
215
42
29
63
10
19
64 km/hr.
7
1
10
2
2
80
10
<1
1
4
2
96 km/hr.
40
2
2
5
<1
2
4
6
<1
1
15
2
2
1
-------
- 76 -
exhaust stream. This could result in an increase in the metallic
content of exhaust particulate relative to conventional vehicles.
IV.2.3.1 Emission Rates of Platinum
Portions of the glass fiber filters were analyzed for platinum.
In no case was platinum detected. Based on the detection limits of
0.35 ygms/cmS platinum emission rates must be below the following
values for the vehicle tests shown below in Table IV-9.
TABLE IV-9
MAXIMUM POSSIBLE PLATINUM EMISSION RATES
Maximum Possible
Platinum Emission
Test Rates, gms/km
1975 FTP 5.6 x 10~5
64 km/hr., 1 hr. 1.6 x 10~5
96 km/hr., 2 hrs. 5.2 x 10~6
IV.2.3.2 Emission Rates of Aluminum
Figure IV-40 shows the aluminum emission rates on the initial
1975 FTP for the base case vehicle and for the vehicle equipped with the
nine catalysts, for each of the three test fuels. It can be seen that
the aluminum emission rates are generally higher when the vehicle is
equipped with a catalyst indicating that some attrition of the catalyst
substrate may have occurred. The maximum emission rate observed was
with the Engelhard pelleted catalyst system, 0.00045 gms/km, which was
about six times greater than the maximum rate observed with the
unequipped vehicle.
The inability to detect platinum is consistent with the
observed aluminum emission rates. For example, even at the highest
aluminum emission levels observed,about 0.001 gms/km, the platinum could
be as much as 5~6% of the aluminum content and still be below our
platinum detection limits. Since the platinum content is well below
1% of the substrate, it should not be detected in auto exhaust particulate.
IV.2.3.3 Emission Rates of Lead
Figure IV-41 shows the lead emission rates for the base case
vehicle, and when the vehicle was equipped with each of the nine
catalysts on the initial 1975 FTP for each test fuel.
-------
FIGURE IV-AO
ALUMINUM EMISSION RATES, gms/km OBTAINED WITH INDICATED
CATALYST. INITIAL 1975 FTP. = 0.019% S. Q= 0.110% S. = 0.091% S
M
B,
tO
ft
CO
CO
H
g
u
B
i-l
0.00050
0.00045
0.00040
0.00035
0.00030
0.00025
0.00020
0.00015
0.00010
0.00005
Base
Case
Engelharc
Monolith
UOP(l)
Monolith
UOP(2)
Monolith
Matthey
Bishop
Monolith
Engelhard
Pellet
Grace
Pellet
Air
Products
Pellet
Grace
Gould
No
Catalyst
Oxidation Catalysts
NOX Reduction
Catalysts
-------
FIGURE IV-41
LEAD EMISSION RATES, gins/km OBTAINED WITH INDICATED CATALYST,
INITIAL FTP, = 0.0197. S, O = 0.110% S. = 0.091% S
CO
cu
o
H
CO
(0
H
A
O
CO
0)
0.0020
0.0018.
0.0016.
0.0014-
0.0012
0.0010
0.0008
0.0006
0.0004
0.0002
Base
Case
Engelhard
Monolith
UOP(l)
Monolith
UOP(2)
Monolith
A
(0.005)
Matthey
Bishop
Monolith
Engelhard,
Pellet
Grace
Pellet
Air
Products
Pellet
Grace
A
Gould
oo
I
No
Catalyst
Oxidation Catalysts
NOX Reduction
Catalyst
-------
- 79 -
With the exception of the FTP's with the Matthey-Bishop
monolith and the Engelhard pelleted system, the lead emission rates
of the vehicle equipped with the other catalyst systems was indis-
tinguishable from those of the base case vehicle. It would be expected
that the lead emission rates would be independent of whether or not
the vehicle was equipped with a catalyst since the leaded particulate,
unlike the other metallic participates, is ultimately fuel derived.
Previous studies with production vehicles operating on leaded fuels
have shown that the lead emission rate measured at any instant of
time in the life history of a vehicle is not necessarily representative
of the average amount of lead emitted over its lifetime (23).
Figure IV-42 shows the lead emission rates for the base case
vehicle, and for the catalyst vehicle on the second FTP. It can be
seen that, in general, the lead emissions are lower on the second FTP
of the test sequence. The lead emission rate from the Engelhard pelleted
catalyst-equipped vehicle is still higher than the base case vehicle
or when the vehicle is equipped with the other catalysts, excepting
the Engelhard monolith.
The higher lead emissions from the Engelhard pelleted catalyst-
equipped vehicle may be due to its greater storage capability than other
catalytic systems,so that it emits more leaded particulate than the
other systems when conditions are favorable for release. The increased
lead particulate emissions exhibited by the Engelhard monolith-equipped
vehicle may be due to an unrepresentative erratic release.
The high lead emissions obtained with the Engelhard monolith
could also be related to failure of a previous Engelhard system as a
result of misfire under high speed cruise. This resulted in catalyst
temperature above 1100'C for about 10 minutes. The test was terminated,
new plugs installed, and the vehicle checked out.
A 1975 FTP the following day (Run No. 35, Appendix E) showed
that the catalyst had become deactivated as evidenced by considerably
higher CO, hydrocarbon, and S02 emissions than the initial FTP (Run No.
31, Appendix E) The lead emission rates on the FTP with the deactivated
catalyst were the highest obtained in all the test runs except for one
run with the Matthey-Bishop catalyst. The leaded particulate may have
been driven off the catalyst substrate during failure of the catalyst
deposited downstream, and a portion emitted on the FTP run with the
deactivated catalyst.
The lead emission rates shown in Figures IV-42 to IV-43
are for the vehicle re-equipped with a new Engelhard monolith which was
subjected to an accelerated conditioning in order to remain on schedule.
The higher lead emission rates observed with this catalyst may be due
to entrained exhaust lead deposits that were present in the exhaust
system as a result of failure of the previous catalyst.
-------
FIGURE IV-
LEAD EMISSION RATES, gms/km OBTAINED WITH INDICATED CATALYST,
1975 FTP, = 0.019% S,O = 0.110% S, = 0.091% S
(* Filter of Second FTP for Matthey Bishop Sent to EPA for Analysis)
0.00100
0.00090
J
1 0.00080
&
S 0.00070
&
g 0.00060
H
CO
CO
6 0.00050
"O
3 0.00040
0.00030
0.00020
0.00010
Base
Case
_
.
_
.
-
- N
i
J
i
'
i
No
Catalyst
Engelhard
Monolith
R
I \
;\
I k
i
i
i
i
1
l
l
£
UOP(l)
Monolith
i
\
\
\
\ /
d
UOP(2)
Monolith
\
\
V
f\--l J A_
Matthey
Bishop
Monolith
ifc
J>
*Jf\
^U
ion Catalyi
Engelhard
Pellet
t
1
l
l
1
i
i
1
i
1
1
1
l
1 f
&
Grace
Pellet
\ /
Air
Products
Pellet
P
^ /
V
Grace
l
i
» r
\ /
»/
b
Gould
f
l
l
l
r'
NO Reduction
3CS Catalyst
00
o
-------
FIGURE IV-43
LEAD EMISSION RATES AT 64 AND 96 km/hr CRUISE OBTAINED WITH
INDICATED CATALYST. = 0.019% S. Q= 0.110% St = 0.0917. S
0.00100 -
4
CO
I
0)
00
c
o
H
CO
M
H
e
w
o
CO
-------
- 82 -
Figure IV-43 shows the lead particulate emission rate for all
catalyst-fuel combinations on the 64 and 96 km/hr. cruises. It can be
seen that excepting both the monolithic and pelleted Engelhard catalyst
runs, the lead emissions from the other catalyst runs were indistinguishable
from the base case vehicle runs.
Generally, the emitted lead was considerably less than 50%
of the lead burned. For example, with the unequipped vehicle, the
emitted lead accounted for 10 to 23% of the lead burned on the FTP's.
With the Engelhard pelletized oxidation catalyst, the emitted lead
accounted for about 33% of the lead burned.
This agrees well with other workers (23) using a leaded fuel
containing 3 grams of lead per gallon as motor mix. These workers
found that the emitted lead accounted on the average for about 48% of
the lead burned. It is reasonable to expect that if only about half
of a much higher lead input can be accounted for, the emitted lead
levels in our work should account for still smaller fractions of the
lead input. For example, with the Grace pelletized oxidation catalyst-
equipped vehicle, an average of about 9% of the input lead could be
accounted for in the emissions for the 6 FTP's.
IV.2.3.4 Emission Rates of Iron
Figure IV-44 shows the iron emission rates obtained on the
first 1975 FTP for the unequipped vehicle, and for the vehicle equipped
with the various catalysts. As in the previous sections, the results
are shown for each of the test fuels.
It can be seen that the emission rate of particulate iron is
generally higher when the vehicle is equipped with oxidation catalysts
than for the unequipped vehicle and the NOX reduction catalyst-equipped
vehicle. This suggests that the increase in iron emissions above the
levels of the unequipped vehicle may be due to reaction of the exhaust
system with catalytically produced sulfuric acid. However, it will be
noted that the iron emission rate appears to be Independent of the fuel
sulfur content (or sulfate emission level). This may be due to a
surface limited reaction of iron in the walls of the exhaust system
with catalytically produced sulfuric acid. The increased iron emissions
above the usual levels associated with engine and exhaust system wear
is probably due to both factors (usual attrition plus reaction with
sulfates) operating.
-------
FIGURE IV-44
IRON EMISSION RATES, gins/km OBTAINED WITH INDICATED CATALYST
INITIAL 1975 FTP. = 0.019% S, O = 0.110% S, = 0.091% S
(0.0049)
J
CO
5
o
H
a
0)
1-1
o
0.00250
0.00200
0.00150
0.00100
0.00050
Base
Case
( 0.0049)
Engelhard
Monolith
UOP(l)
Monolith
r
o-a
UOP(2)
Monolith
Matthey
Bishop
Monolith
Engelhard
Pellet
Grace
Pellet
Air
Products
Pellet
Grace
\
Gould
oo
OJ
No
Catalyst
Oxidation Catalysts
NOx Reduction
Catalysts ~
-------
- 84 -
IV.2.3.5 Emission Rates of Nickel
Figures IV-45 and IV-46 show the nickel emission rates
on the first and second FTP's respectively for all vehicle-catalyst-
fuel combinations. It can be seen that the nickel emission rates are
independent of fuel sulfur content. The nickel emission rates of
the base case vehicle was the same as when the vehicle was equipped
with each of the seven oxidation catalysts, and with the Grace NOX
reduction catalyst. Dramatic increases in the nickel emission rates
were observed when the vehicle was equipped with the Gould NOx
reduction catalyst.
These results with the Gould NOx reduction catalyst are
similar to what was obtained in earlier pre-contract work with
Gould NOx reduction catalysts (3). The nickel emission rates from
the Gould NOX reduction catalyst-equipped vehicle on the 1975 FTP
ranged from 1 x 10~3 to values exceeding 2 x 10~3 gins/km. Earlier
results on a somewhat different Gould NOx reduction catalyst showed that
on the 1972 FTP, nickel emission rates ranged from 2 x 10~3 to
8 x 10-3 gms/km.
The nickel emission rates on the steady state cruises were
lower than FTP emission rates, as all metal derived particulate emissions
were. However, differences between the Gould catalyst-equipped vehicle
and the base case vehicle, and the vehicle equipped with the other
catalyst systems are readily discernible. Steady state cruise nickel
emissions with the Gould catalyst-equipped vehicle are 2 to 5 times
higher than that observed with the other systems.
Preliminary A/F measurements on the test vehicle equipped with
the Gould catalyst indicates that removal of the air pump was sufficient
to produce net rich conditions as required for proper operation. However,
detailed A/F measurements performed after the catalyst was conditioned
and run through the program test sequence showed that the vehicle was
operating in the lean mode. The increased nickel emissions, therefore,
may be the direct result of improper lean operation.
IV.2.3.6 Emission Rates of Copper
Figures IV-47 and IV-48 shows the copper emission rates on
the initial and final FTP's respectively for all catalyst-fuel combinations.
The FTP copper emission rates are generally below 6 x 10~4 gms/km. Some-
what higher rates are observed with the Engelhard monolithic and pelleted
catalyst system. These differences, if significant, may simply reflect
the different levels of trace metals in the various catalyst systems.
-------
FIGURE IV-45
NICKEL EMISSION RATES, gins/km OBTAINED WITH INDICATED CATALYST,
INITIAL 1975 FTP. = 0.019% S. O = 0.110% S. = 0.091% S
0.00250
J
CO
a
0>
6
1-1
en
09
Q>
O
rl
a
0.00200
0.00150
0.00100
0.00050
Base
Case
Engelhard
Monolith
No
Catalyst
UOP(l)
Monolith
A,
UOP(2)
Monolith
Matthey
Bishop
Monolith
Engelhard. Grace
Pellet
1
Pellet
Air
Products
Pellet
Grace
Gould
00
U1
Oxidation Catalysts
NO Reduction
XCatalysts
-------
FIGURE IV-A6
NICKEL EMISSION RATES, gms/km OBTAINED WITH INDICATED CATALYSTS,
FINAL 1975 FTP. = 0.019% S. O = 0.110% S. = 0.091% S
0.00100
0.00090
^ 0.00080
m
g>
. 0.00070
r^
S 0.00050
H
^ 0.00040
0)
u
£ 0.00030
0.00020
0.00010
n
Base
Case
-
-
^
_
_
_
- +-0-*
No
Catalyst
Engelhard
Monolith
»-c/
UOP(l)
Monolith
-0-B
UOP(2)
Monolith
-0-B
f\-- J J j
Mat they
Bishop
Monolith
~o-*
:ion Catal)
Engelhard
Pellet
V
Grace
Pellet
0-B
Air
Products
Pellet
-o-m
Grace
-0-B
Gould
-0-B
NO Reduction
scs Catalysts
00
-------
FIGURE IV-47
COPPER EMISSION RATES, gms/km OBTAINED WITH INDICATED CATALYST
INITIAL 1975 FTP. = 0.019% S. O = 0.110% S. = 0.091% S
0.00100
(U
4-1
c
O
t-4
a
in
H
MJ
u
0.00050
Base
Case
Engelhard UOP(l) UOP(2)
Matthey Engelhard Grace
Monolith
Monolith
No
Catalyst
Monolith
Bishop
Monolith
^Filter
sample
sent to
EPA
Pellet
Pellet
Air Grace
Products
Pellet
Gould
oo
I
Oxidation Catalysts
_NOx Reduction
Catalysts
-------
FIGURE IV- 48
COPPER EMISSION RATES, gins/km OBTAINED WITH INDICATED CATALYST
FINAL 1975 FTP. = 0.019% S. O = 0.110% S.B= 0.091% S
0.00100
0.00090
j 0.00080
| 0.00070
oT
£ 0.00060
2
c
-S 0.00050
M
l/l
lrl
J3 0.00040
H
£ 0.00030
o
0
0.00020
0.00010
0
Base
Case
k
»
^
^
^^
^l
- O-«
-
No
Catalyst
Engelharc
Monolith
UOP(l)
Monolith
UOP(2)
Monolith
V
Matthey
Bishop
Monolith
*Filter
sample
sent to
EPA
Oxidation Catalys
Engelhard
Pellet
f
/
/
^
\ /
\/
\/
M
vy
Grace
Pellet
V.
Air
Products
Pellet
O-«
Grace
7
Gould
r
NQ, Reduction
Catalysts
oo
00
-------
- 89 -
IV.2.3.7 Emission Rates of Zinc
Figure IV-49 shows the zinc emission rates on the initial
1975 FTP for all catalyst fuel combinations. Although there seems to
be no correlation between zinc emissions and fuel sulfur level, there
does appear to be some correlation with the level of sulfate produced
by a given catalyst. The lowest zinc emission rates were obtained
with the base case vehicle and the vehicle equipped with the NOx
reduction catalysts, where little, if any, sulfuric acid is observed.
There is not a one-to-one correspondence on a single run between the
sulfuric acid emission and zinc emission rate. This could be due to
the generally erratic pattern of metallic vehicular emissions. Thus,
for example, the high zinc emissions observed in a given run may be
zinc that corroded or reacted with sulfuric acid in an earlier or
previous run. At other times, much of the emitted zinc may be that
which had reacted with sulfuric acid generated in the same run. The
source of the zinc emissions has not been traced, although the muffler
system is a likely source. Zinc is also present in the lubricant.
IV.2.3.8 Emission Rates of Calcium
Calcium emission rates observed on the FTP shown in Figure
IV-50 are independent of fuel sulfur level. With minor differences,
the calcium emission pattern and level are the same both for all the
catalyst systems and the base case vehicle. This would be expected if
the calcium containing exhaust particulate was derived from the lubricating
oil.
On the FTP's the calcium emission rates were of the order
of 1 x 10-4 to 2 x 10"^ gms/km. The lubricating oil used contained
about 0.16 and 0.21 wt. % calcium, equivalent to about 1.7 gms calcium
per quart. Typical oil consumption rates for new vehicles is about
0.2 quart per 1600 km.
The calcium emission rate corresponding to this consumption
rate is about 2.1 x 10~4 gms/km. This is in excellent agreement with
the calcium emission rates shown in Figure IV-50, indicating that
25% to virtually all of the calcium associated with the consumed
lubricating oil is emitted as exhaust particulate. As with the other
metal derived exhaust particulate, steady state cruise calcium
emission rates are lower than the FTP values, accounting for about
10 to 15% of the calcium.
IV.2.3.9 Emission Rates of Chromium
The chromium emission rates obtained on the initial FTP are
shown in Figure IV-51. It can be seen that the chromium emission rates
are Independent of fuel sulfur content. Both Engelhard catalyst systems
(monolith and pelletized) and the first UOP catalyst tested generally
-------
FIGURE IV-49
ZINC EMISSION RATES, gms/km OBTAINED WITH INDICATED CATALYST,
INITIAL 1975 FTP = 0.019% S. O = 0.110% S.»= 0.091% S
0.00200
(0
& 0.00150
ti
0)
3
w
2 0.00100
I
u
0.00050
Base
Case
0 No '
Catalyst
Engelhard
Monolith
UOP(l)
Monolith
UOP(2)
Monolith
Matthey
Bishop
Monolith
Engelhard Grace
Pellet
Pellet
Air
Products
Pellet
Grace
Gould
vo
o
Oxidation Catalysts
NOX Reduction
Catalysts
-------
FIGURE IV-50
CALCIUM EMISSION RATES, gms/km OBTAINED WITH INDICATED CATALYSTS,
INITIAL FTP. = 0.019% S, O = 0.110% S, = 0.091% S
0.00100
0.00090
4 0.00080
CO
1
0.00070
A
0)
4J
5 0.00060
c
0
H
S 0.00050
'e
w
g 0.00040
r-4
o
£ 0.00030
o
0.00020
0.00010
Base
Case
-
-
_
-
_
-
-
_
V*-
No
Catalyst
Engelhard
Monolith
A
UOP(l)
Monolith
V.
UOP(2)
Monolith
^*
nv^/ia
Mat they
Bishop
Monolith
^LjffL^f
^j j~^
tion Catal
Engelhard
Pellet
J
Grace
Pellet
^
Air
Products
Pellet
-0-*
Grace
^
Gould
~-
NOX Reduction
3 Catalysts
I
VO
M
'
-------
FIGURE IV-51
CHROMIUM EMISSION KATES, gins/km OBTAINED WITH INDICATED CATALYSTS
INITIAL 1975 FTP. = 0.019% S.O= 0.110% S, = 0.091% S
0.00050
I
M
0.0004C*.
e
o
u
0.00030U
0.0002C .
0.00010
c
Base
Case
Engelhard
Monolith
UOP(l)
Monolith
UOP(2)
Monolith
Matthey
Bishop
Monolith
Engelhard
Pellet
Grace
Pellet
Air
Products
Pellet
Grace
Gould
VO
to
No
Catalyst
Oxidation Catalysts
_NO Reduction
Catalysts
-------
- 93 -
showed somewhat higher emissions than the base case vehicle, or the
vehicle equipped with the other catalyst system.
Elemental analysis on a monolithic Engelhard catalyst carried
out at Exxon several years ago showed that chromium was present, so
that the Engelhard catalyst systems may be a source for the low chromium
emissions observed. These analyses also showed that copper was another
elemental constituent such that the copper to chromium ratio averaged
about 8 to 1. The ratio of the emitted copper to chromium for the
Engelhard monolith was found to range from about 4 to 7.5 in reasonably
good agreement with the analysis supporting the hypothesis that these
metals are catalyst derived.
No such analytical data is available for the Engelhard
pallatized catalyst or the UOP monolithic system. It is probable,
however, that in these cases, the catalyst systems are also the sources
of the low level chromium emissions.
IV.2.4 Metal Oxide Emission Rates Following
Sulfate Storage Conditioning
Metal emission rates were measured on the test sequence carried
out following the 3200 km conditioning on the Federal Durability Cycle
of the Engelhard palletized oxidation catalyst-equipped vehicle. The
detailed metals emission results are given in Appendix E.
Although sulfate and S02 emissions exceeded the theoretical
values based on test fuel consumption, the metal emission pattern
following storage conditioning was essentially unchanged from that
observed after standard conditioning and testing. Table IV-10 shows
the comparison of the total metal oxide emission rates for the two
sets of conditioning and test sequence.
TABLE IV-10
Comparison of Metal Oxide Emission Rates;
Vehicle Equipped with Pelletized Engelhard Oxidation Catalyst,
Test Fuel 0.019% S
Metal Oxide Emission Rate,
ems/km
Test Standard Storage
Type Runs Runs
1975 FTP 0.0060 0.0070
64 km/hr. 0.0008 0.0004
96 km/hr. 0.0040 0.0004
1975 FTP 0.0090 0.0030
The large difference exhibited at the 96 km/hr. cruise are
not believed to be of significance in view of the generally erratic
behavior of metallic emissions previously discussed.
-------
- 94 -
IV.3 Organic Exhaust Particulate Emissions
The organic portion of exhaust particulate was to be measured
in terms of its carbon content using the semi-microcombustion technique
described in Appendix A, Section A.3. Although this technique also could
measure the hydrogen content of exhaust particulate, it was not used
since it would include the hydrogen present in the particulate as
water of hydration. Our earlier work has shown that most of the hydrogen
in particulate is present as water of hydration which can be determined
separately by the Karl Fisher method discussed in Appendix A, Section
A.4.1. Organic hydrogen determined as the small difference between two
larger numbers (semi-microcombustion minus Karl Fisher hydrogen) would
be an extremely inaccurate number. Consequently, the semi-microcombustion
technique was not used to determine organic hydrogen.
The presence of organic nitrogen in exhaust particulate was
determined using sensitive spot tests. These tests are discussed in
Appendix A, Section A.A.2 and the results in Section IV.3.3. Organic
sulfur compounds in exhaust particulate are discussed in Section IV.1.6.
IV.3.1 Carbon Content of Exhaust Particulate
Previous tests had shown that the semi-microcombustion
technique may not be sufficiently sensitive to determine organic
particulate as carbon, particularly in the case of oxidation catalyst
equipped vehicles. The Type A Gelman glass fiber filters used in this
program although ostensibly free of organic binder gave somewhat high
and variable carbon blanks, which averaged in terms of equivalent emis-
sion rates, 0.0014 gms/km for the 1975 FTP, 0.0004 gms/km for the 64
km/hr (40 mph) cruise and 0.0001 gm/km for the 96-112 km/hr (60-70
mph) cruises. As applied to analysis of the carbon content of exhaust
particulate laden filters, this method is at best semi-quantitative.
Carbon analysis was performed for the base case runs, and for
the 1975 FTP and 64 km/hr cruises for the catalyst equipped vehicle.
The detailed results are given in Appendix E. Table IV-11 below
compares the organic carbon particulate with the total particulate for
the base case vehicle on the 1975 FTP and 64 km/hr test runs on all three
fuels. This vehicle was the one which in subsequent tests was equipped
with the various caralysts that were screened on this program.
For discussion purposes, the catalysts in Table IV-H are
tabulated with respect to type, not the chronological order in which
it was screened.
For the base case vehicle, the carbon content of the exhaust
particulate ranged from 25 to 60% of the total particulate.
Carbon particulate from the Engelhard monolith equipped
vehicle with several exceptions were lower than the base case vehicle,
ranging from essentially zero to at most 11% of the total particulate.
-------
- 95 -
Table IV- 11
Comparison of Carbon and Total Particulate Emissions
Emission Rate,
gins /km as
Run
No.
16
18
20
21
23
25
26
28
30
36
Test Type
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
% Fuel
Sulfur
0.019
11
11
0.110
ti
n
0.091
II
11
0.019
Catalyst
None
n
n
"
n
n
n
n
"
Engelhard
Carbon
0.002
0.001
0.005
0.007
0.002
0.006
0.007
0.003
0.009
0.002
Total
Particulate
0.015
0.002
0.019
0.014
0.004
0.010
0.014
0.005
0.014
0.031
38
40
41
43
45
46
48
50
66
68
70
71
73
75
76
80
141
143
145
146
148
150
151
153
155
81
83
85
86
88
90
91
93
95
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
Monolith
0.110
II
II
0.091
0.019
0.110
it
n
0.091
0.019
0.110
it
n
0.091
0.019
0.110
n
0.091
n
n
n
n
it
n
n
UOP(l)
II
II
II
UOP(2)
n
n
ti
n
tt
Matthey Bishop
n it
n
n
it
n
n
it
n
n
it
0.000
0.000
0.002
0.005
0.014
0.014
0.005
0.015
0.019
0.005
0.015
0.015
0.006
0.012
0.014
0.014
0.012
0.000
0.001
0.001
0.002
0.001
0.001
0.006
0.005
0.014
0.004
0.015
0.015
0.004
0.014
0.014
0.004
0.015
0.018
0.043
0.169
0.262
0.150
0.226
0.192
0.131
0.029
0.037
0.035
0.104
0.490
0.090
0.134
0.042
0.023
0.025
0.014
0.070
0.363
0.151
0.173
0.356
0.134
0.028
0.014
0.021
0.086
0.118
0.050
0.069
0.087
0.040
-------
- 96 -
Table IV-11 (Cont'd.)
Run
No.
55
Test Type
75 FTP
60
61
63
65
126
128
130
131
133
135
136
138
140
156
158
160
161
163
165
166
168
170
96
98
100
101
103
105
106
108
110
113
115
116
121
123
125
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
75 FTP
40(1)
75 FTP
40(1)
75 FTP
75 FTP
75 FTP
40(1)
75 FTP
% Fuel
Sulfur
0.019
0.110
0.091
0.019
n
n
0.110
M
0.091
0.019
n
0.110
0.091
0.019
0.110
II
0.091
n
n
0.019
n
0.110
0.091
n
n
Emission Rate,
gms/km as
Catalyst
Engelhard
Pellet
II
II
Grace Pellet
MM
II
II
II
II
II
II
II
II
II
II
II
Air Products
Pellet
Grace NOV
A
Reduction
Gould NOX
Reduction
Carbon
0.015
0.015
0.015
0.015
0.014
0.013
0.004
0.012
0.014
0.005
0.017
0.013
0.004
0.011
0.002
0.001
0.000
0.002
0.003
0.002
0.002
0.004
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.002
0.004
0.016
0.004
0.006
0.014
0.016
0.004
0.018
Total
Particulate
0.036
0.083
0.062
0.201
0.064
0.044
0.016
0.026
0.027
0.117
0.065
0.066
0.140
0.051
0.034
0.020
0.010
0.051
0.149
0.106
0.043
0.099
0.123
0.007
0.005
0.017
0.016
0.133
0.019
0.020
0.118
0.041
0.005
0.013
0.025
0.031
0.089
0.019
-------
- 97 -
There are differences not understood between the two UOP oxi-
dation catalysts. The UOP(l) system shows a carbon emission rate generally
higher than the base case vehicle, whereas the UOP(2) system shows with one
exception lower carbon emissions that the base case vehicle. A suggested
possible explanation is that the emission pattern of carbonaceous exhaust
particulate may be similar to the metal oxide emission pattern. Thus,
a portion of the carbonaceous material collected during the UOP(l) runs
may have been re-entrained carbon deposits and not freshly made carbon-
aceous material. The base case tests regarding carbon emissions may
be atypical in that the emissions were coursing through a clean exhaust
system. Thus, an appreciable fraction of the carbonaceous particulate
matter produced in the base case runs may have deposited on the walls
of the exhaust pipe and re-emitted in subsequent test runs. Although
both catalysts met the stringent CO and hydrocarbon standards, the UOP(l)
catalyst vehicle consistently showed higher CO emissions. This may
also be a factor involved in the different levels of carbonaceous
particulate by the two UOP catalyst systems.
The carbon emission rates on the FTP's for the Matthey Bishop
catalyst equipped vehicle are consistently higher than the base case
vehicle whereas the emission rates under cruise conditions are generally
lower. The higher carbonaceous particulate emission rates on the FTP
may not only be due to the cold starts, but also to the effect of
vehicle aging in terms of carbonaceous deposits, which may be released
and re-entrained during the acceleration and deceleration portions
of the driving cycle.
A similar carbon emission pattern to the Matthey Bishop
system was observed with the Engelhard and Grace palletized catalyst
equipped vehicle. Presumably these patterns are due to similar but
undetermined factors operating in each case.
The carbonaceous exhaust emission rates with the Air Products
catalyst equipped vehicle are the lowest that have been obtained of all
the oxidation catalysts that have been screened.
The lowest carbon emission rates regardless of the catalyst
type screened were obtained with the Grace NOX reduction catalyst. A
possible explanation is that the order of catalyst testing may have a
greater effect on transient carbonaceous emissions than the catalyst
itself.
The particulate emissions from the Gould NOx reduction
catalyst equipped vehicle are predominantly carbonaceous with the exception
of a 64 km/hr cruise, run 123 Table IV-11. The operating conditions
in that run were sufficiently lean to produce sulfuric acid at an emission
rate of 0.034 gms/km. If it is assumed that the H^SO, particulate is
about a 50 wt.% aqueous solution, then the particulate emission rate
-------
- 98 -
for run 123 excluding H2SO^ and bound water is 0.021 gms/km. The
carbon particulate now constitutes 25% of the residual particulate.
In general, the interpretation of the organic particulate
emissions from the catalyst equipped vehicle is difficult since the
test sequence was designed for a gross characterization of exhaust
particulate, rather than for the elucidation of the detailed mechanism
of organic particulate formation and emission. For example, there is
no way to assess the effects if any of the test sequence on the resultant
organic particulate emission rates. In addition, the screening program
was not designed to separate cold start effects from cycling effects,
both of which could markedly influence organic particulate emission
rates.
IV.3.2 Organic Nitrogenous Particulate
Chemical spot tests were carried out on particulate samples
generated from the 1975 FTP and 64 km/hr (40 mph) test runs for
nitrogenous organic material. As in the case of non-sulfate sulfur
particulate analysis, the samples analyzed included those from runs
on the unequipped vehicle, and when the vehicle was equipped with the
various catalysts screened on the test program.
Low levels of nitrogenous particulate matter should be
readily detectable due to the extreme sensitivity of the tests. Negative
results would establish the maximum emission rate possible. This
maximum rate is based on the test sensitivity, the mileage accumulated
on the particular test run, and the fraction of the filter area
selected for testing. The spot tests used are listed in Feigl(22),
and are discussed in detail in Appendix A, Section A.4.2.
Table IV-12 below shows which nitrogenous organic compounds
were tested for, and the maximum emission rates for the 1975 FTP and
64 km/hr cruise based on negative results.
Table IV-12
ESTIMATED AVERAGE MAXIMUM EMISSION RATES
AS DETERMINED BY DETECTION LIMITS
gms/km, on Indicated Test
Compound Type 1975 FTP 64 km/hr Cruise
Organic Nitrogen 1 x 10~5 2.5 x 10"
Compounds with 2 x 10~* 5 x 10~5
Nitrogen-oxygen bonds
Aliphatic and Aromatic - in~^ 7 «
_ J .X J.U / .
Nitro Compounds
Primary Aliphatic Nitro 2 x 1Q-4 5 x 1Q
Compounds _, _4
Aromatic Nitro Compounds 6 x 10~ 1.5 x 10
Nitrates, Nitrites 3 x 10~4 8 x 10~6
Aliphatic and Aromatic -3 x 1Q-3
Nitriles » ~
Aliphatic Nitriles 4 x 10 1 x 10
-------
- 99 -
The selection of the compound types In the above table as
possible exhaust particulate components is based on chemical species
known to be present in auto exhaust which could function as precursors
or as reactants involved in their production. The basis of this selec-
tion is discussed in Appendix D. Two of the three test fuels contained
nitrogenous additives such that the nitrogen content of the fuel due to
these additives is only about 3 ppm by weight.
All tests for the nitrogenous compounds listed in Table IV-12
were negative. No nitrate other than normal filter background (M).l
Ugm/cm^) was detected. There are two tests for nitrate which have
detection limits of 0.5 and 0.07 ygms of nitrate, respectively. The
less sensitive test was always negative, the more sensitive one always
positive when a 0.39 cm2 section of filter was tested. The background
nitrate level corresponds to an emission rate for the 1975 FTP of about
3 x 10~5 gms/km, the detection limit of the more sensitive test for
nitrate. The nitrate emission rate corresponding to the detection limit
of the less sensitive test which was always negative is 2 x 10"^ gms/km.
Thus, it may be inferred from the above discussion that the detected
nitrate is the background nitrate on the filter.
It is not surprising that none of the nitrogen containing
compound types were found in exhaust particulate. The major reason
is that there is not enough of the nitrogenous additives present in
the fuel to produce sufficient quantities of exhaust nitrogen compounds
to have a two-phase (vapor plus liquid) co-existence. Only the liquid
form would be collected as particulate matter, and it cannot exist as
liquid under the test conditions. This is discussed in detail in Appendix
D which also includes a sample calculation for demonstration.
Only high molecular weight nitrogenous organic compounds
could exist as particulate matter under vehicle test conditions, and it
is unlikely that these wo'uld survive the combustion process intact.
Consequently, the only mechanism whereby organic nitrogen compounds
could be present as exhaust particulate would be if they were strongly
absorbed by exhaust particulate. The failure to detect these compounds
indicates that absorption of appreciable amounts of these compounds
on exhaust particulate does not occur.
-------
- 100 -
IV.4 Size Distribution of Exhaust Particulate
Size distribution of the exhaust particulate was determined
using the modified Andersen Impactor in parallel with the other sampling
probes. The results obtained with the impactor were considered valid
only if the normalized total particulate emission rates obtained with
the impactor (sum of weight gains of the impactor stages and final
filter) agreed with the total filter particulate emission rates. Accept-
able internal agreement between the impactor measured emission rates
and total filter measured total particulate emission rates were obtained
in about 20% of the runs. It is believed that the major source of the
discrepancy was due to improper placement of the final filter in the
impactor. This filter holder could not be sealed in the filter holder, so
that large portions of aerosol could be lost by improper placement. The
rapid disassembly and reassembly of the impactor that was required on
the days when 4 tests were conducted on the vehicle may have contributed
to many instances in which the final filter was misaligned. Periodic
checks showed that variable flow rates and visible leaks around the
collection surface were not sources of error.
The nature of the program was such that considerable time
lags occurred between sample generation and weighing of the impactor
plates. Consequently, the extent of the discrepancy was not noted
till late in the program. However, it should be noted that those cases
where agreement was obtained included FTP's. Table IV-11 shows the com-
parison of the total particulate emission rates obtained with the impactor
and the total filter. The asterisk marked runs denote those in which the
agreement between the impactor and the total filter were sufficiently
close so that the impactor results could be considered valid. Figures
IV- 52 to IV- 67 show the log normal distribution plots for the asterisk
marked runs.
IV.4.1 Particle Size Distributions. Base Case Vehicle
For the base case vehicle runs, Figures IV-52 to IV-56 the pre-
dominant fraction of the particles are under 2 microns. For the FTP's
shown in Figures IV- 52 and IV- 55, the cumulative % mass of particles less
than 2 microns ranged from 91.5 to 95%. For the hot start cruises,
the cumulative % mass of particles less than 2 microns, Figures IV-53, IV-54
and IV- 55, the cumulative 7. mass shifted to a range of 96 to 98.6%. The
major difference between the cold start cyclic testing and the hot start
cruises is most likely the result of greater production of organic
particulate during the cold start. A comparison of the organic emissions
(as carbon) Section IV.3.1, shows that the hot start cruises for the
base case vehicle consistently produces lower levels of these emissions.
IV.4.2 Particle Size Distributions, Oxidation
Catalyst Equipped Vehicle
With oxidation catalyst equipped vehicles, the cumulative % mass
of particles less than 2 microns shifted from 98.2 to 99.7%, Figures IV-57
to IV-61. This means that exhaust particulate from oxidation catalyst
equipped vehicles is smaller than that emitted from a conventional vehicle.
Virtually none of the particles are in the size range above 2 microns.
There is not sufficient data to show trends in operating conditions or fuel
sulfur levels. However, in the cases with the oxidation catalyst equipped
vehicle, the sulfuric acid aerosol accounted for about 50% of the total
particulate. Thus, taking into account the bound water associated with the
acid, the particulate is predominantly sulfuric acid aerosol.
-------
10.0
Figure IV-52
Size Distribution of Total Particulate,
Base Case Vehicle. 1975 FTP, Run No. 6
Figure IV-53
Size Distribution of Total Particulate,
Base Case Vehicle, 113 km/hr Cruise. Run No.
01
g
M
0)
4J
(U
a
.H 1.0
u
CO
PL,
CO
rl
1
0.1
10.0
§
M
U
1.0
U
H
4J
t-l
CO
On
H
70 90 98 99.5
Cumulative % ,
-------
lo.o:
Figure IV-54
Size Distribution of Total Particulate,
Base Case Vehicle 113 km/hr Cruise, Run No.
Figure IV-55
Size Distribution of Total Particulate,
Base Case Vehicle, 1975 FTP Run No. 15
CO
a
o
M
0)
H 1.0
M
to
c
0)
1-1
n)
H
I
0.1
10.0
M
u
3
-------
10.
Figure IV-56
Size Distribution of Total Particulate,
.Base Case Vehicle. 64 km/hr Cruise. Run No. 29
Figure IV-57
Size Distribution of Total Particulate, Matthey Bishop
Catalyst-Equipped Vehicle. 64 km/hr Cruise. Run No. 88
0)
O
l-i
u
4J
CO
H
Q
U
M
cd
<0
1.0
70 90 98 99.5
Cumulative %^"Particle Diameter
99.9
0.1
o
LO
70 90 98 99.5
Cumulative %^Particle Diameter
99.9
-------
Figure IV-58
Size Distribution of Total Particulate, Grace Pelletized
Catalyst-Equipped Vehicle. 64 km/hr Cruise. Run No. 133
10.0
w
c
o
a
§
<0
rt
Q
0)
iH
U
(0
Oi
IS
H
1
1.0
0.1
Figure IV-59
Size Distribution of Total Particulate, Grace Pelletized
Catalyst-Equipped Vehicle, 64 km/hr Cruise, Run. No. 138
10.0
m
g
M
O
M
H
a
u
H
4J
£ i.o
R)
70 90 98 99.5
Cumulative %
-------
Figure IV-60
Size Distribution of Total Particulate, Air Products
Pelletized Catalyst Equipped Vehicle 1975 FTP Run tlo. 160
10.0
CO
a
o
7} 1.0
to
d,
c
0)
0.1
Figure IV-61
Size Distribution of Total Particulate, Air Products
Pelletized Catalyst Equipped Vehicle 1975 FTP Run No. 166
10.0
EO
I
O
H
V
0)
H
O
H
a
P-
u
G
U
I
s
1,0
o.i
o
Oi
70 90 98 99.5
Cumulative %
-------
Figure IV-62
Size Distribution of Total Particulate, Grace Reduction
Catalyst Equipped Vehicle, 1975 FTP Run No. 96
10.0
o
u
H
S
-------
Figure IV-64
Size Distribution of Total Particulate, Gould Reduction
Catalyst-Equipped Vehicle, 64 km/hr Cruise, Run Ho. 113
10. Oi
(A
I
-------
Figure IV-66
Size Distribution of Total Particulate, Grace Reduction
Catalyst Equipped Vehicle. 64 km/hr Cruise Run No. 103
10.0
M
s
o
M
0)
Q
-------
- 109 -
Figure IV-68
Size Distribution of Total Particulate, Engelhard
Pelletized Catalyst Equipped Vehicle,
Second 1975 FTP After Sulfate Storage Conditioning. Run No.
175
10.0
CO
C
o
M
0)
-------
- 110 -
In one case with an Air Products catalyst Run No. 160, Figure
IV-60, the cumulative % mass of particles less than 2 microns was 93%,
atypical for oxidation catalyst equipped vehicles. This run was an
FTP with the low sulfur fuel with considerable sulfate storage. Although
the sulf ates accounted for 40% of the total particulate, the total
particulate emission rate was sufficiently low (0.010 gins/km) that the
metal oxide emission rate was 30% of the total rate. Thus it is quite
possible that the relatively large contribution of metal derived exhaust
particulate could have altered the particle size distribution.
IV.4.3 Particle Size Distribution, NO Reduction
Catalyst Equipped Vehicle
With NOX reduction catalyst equipped vehicles, the particle size
distribution on the FTP's generally resembled the base case vehicles.
For these tests, the cumulative % mass of particulates smaller than 2.1
microns equivalent diameter ranges from 88 to 98%, Figures IV-62 to IV-66.
On the cruises, the particle size distribution resembles that of the
vehicle equipped with the various oxidation catalysts. For example
with a Grace reduction catalyst equipped vehicle on a 64 km/hr cruise,
the cumulative % mass of particulate less than 2.1 microns was 99.6%
(Figure IV-66) . This was because of lean vehicle operation over a noble
metal catalyst with a high sulfur fuel. The sulfuric acid emission rate
in this case was 0.065 gms/km, and accounted for almost 50% of the total
particulate. Under these circumstances, it is not surprising that the
particle size distribution resembled that produced by oxidation catalyst
equipped vehicles.
IV.4.4 Particle Size Distributions After Sulfate Storage
Figure IV-67 shows the particle size distribution obtained on
the second 75 FTP of the sulfate storage test run sequence. The dis-
tribution deviates considerably from the log normal distributions exhibited
on the standard oxidation catalyst screening runs Figures IV-57 to IV-61.
It can be seen from Figure IV-67 that unlike the standard screening tests
with the oxidation catalyst equipped vehicle, the cumulative % for particle
equivalent diameters of less than 0.43 microns is about 40%. In this run,
the particulate sulfate emissions exceed 100% based on fuel consumption
values as a result of release of stored sulfate (Section IV.I.5). This
released sulfate may have a larger particle size than sulfate produced
during the run. The quantity of stored sulfate that is released must be
several times that of freshly produced and emitted sulfate. Thus, the
emitted sulfate as a result of storage conditioning may have two particle
size distributions such that the stored sulfate has a larger mass medium
equivalent diameter than freshly produced emitted sulfate.
This can be surmised by the simple expedient of assuming that
the size range of released sulfate is between 0.43 and 0.65 microns, and
that it would not be present in a standard screening run, a log normal
-------
- Ill -
distribution more nearly resembling that obtained on the standard screening
test with an oxidation catalyst equipped vehicle. This plot (backing out
the weight increment on the seventh impactor stage) is shown in Figure IV-64
(open circles). This approach means that about 60% of the emitted sulfate
was released from storage. Although the above arithmetical manipulation
is not conclusive proof of the presence of larger particle size sulfuric
acid, it does substantiate the possibility of its existence. Analysis
of the stages would be required to verify the altered distribution of
sulfuric acid particle size as a result of release of stored sulfur.
-------
- 112 -
Table IV-13
Comparison of Total Particulate Emission
Rates, Andersen Impactor Versus Total Filter
Total Particulate
Emission Rate, gms/km
as Measured by
Run
No.
6
9
11
14
15
16
18
19
20
29
36
38
40
41
43
45
46
48
50
51
53
55
56
58
60
61
63
65
66
6.8
70
71
73
75
76
78
80
Test Type
75 FTP
112 km/hr
75 FTP
112 km/hr
75 FTP
75 FTP
64 km/hr
112 km/hr
75 FTP
112 km/hr
75 FTP
65 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75. FTP
% Fuel
Sulfur
0.110
ii
0.091
ii
ii
0.019
ii
ii
ii
0.091
0.019
0.019
0.019
0.110
it
ii
0.091
ii
n
0.019
n
ii
0.11
II
II
0.091
11
n
0.019
n
n
0.110
II
II
0.091
n
n
Catalyst
None
n
n
n
n
n
n
n
n
Engelhard
Monolith
n
n
n
n
ii
n
n
n
Engelhard
Pellet
n
ii
n
n
n
ti
n
n
UOP(l)
n
n
n
ti
n
n
n
n
Impactor
Stages +
Final Filter
0.026*
0.012*
0.018
0.007*
0.018*
0.009
0.0021
0.002
0.013
0.004*
0.012
0.005
0.006
0.068
0.004
0.007
0.005
0.006
0.008
0.009
0.001
0.003
<0.001
0.003
0.005
0.003
0.201
0.002
0.002
0.011
0.005
0.012
0.342
0.013
0.005
0.149
0.009
Total
Filter
0.026
0.009
0.030
0.008
0.022
0.015
0.002
0.003
0.019
0.004
0.031
0.018
0.043
0.169
0.262
0.150
0.226
0.192
0.131
0.061
0.009
0.036
0.059
0.246
0.083
0.062
0.002
0.201
0.029
0.037
0.035
0.104
0.490
0.090
0.134
0.462
0.042
-------
- 113 -
Table IV-13 (Cont'd.)
Run
No.
81
83
85
86
88
90
91
93
95
96
98
100
101
103
105
106
108
110
111
113
115
116
118
120
121
123
125
126
128
130
131
133
135
136
138
140
141
143
145
146
148
150
151
153
155
Test Type
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
74 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
7. Fuel
Sulfur
0.019
0.110
II
It
0.091
ii
n
0.019
n
0.110
II
II
0.091
n
ii
0.019
n
0.110
It
II
0.091
0.019
n
0.110
II
It
0.091
n
ti
0.019
0.110
n
n
0.091
n
n
Catalyst
Matthey
Bishop
Grace Reduction
n
n
M
Gould Reduction
n
n
n
Grace Pellet
UOP(2)
n
n
Total Particulate
Emission Rate, gms/km
as Measured by
Impactor
Stages +
Final Filter
0.012
0.009
0.021
0.047
0.092*
0.011
0.030
0.058
0.011
0.006*
0.003
0.006
0.015*
0.125*
0.007
0.008
0.118
0.011
0.017
0.005*
0.008
0.009
0.072
0.016*
0.008
0.054
0.020*
0.006
0.008
0.009
0.016
0.172*
0.038
0.018
0.133*
0.011
0.013
0.018
0.007
0.041
0.014
0.011
0.012
0.012
0.026
Total
Filter
0.028
0.014
0.009
0.086
0.118
0.050
0.069
0.087
0.040
0.007
0.005
0.017
0.016
0.133
0.019
0.020
0.069
0.041
0.041
0.005
0.013
0.025
0.116
0.016
0.031
0.089
0.019
0.044
0.016
0.026
0.027
0.177
0.065
0.066
0.140
0.051
0.023
0.025
0.014
0.070
0.363
0.151
0.173
0.119
0.134
-------
- 114 -
Table IV-13 (Cont'd.)
Run
No.
156
158
160
161
163
165
166
168
170
171
173
175
Test Type
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
74 FTP
75 FTP
64 km/hr
75 FTP
75 FTP
64 km/hr
75 FTP
% Fuel
Sulfur
Catalyst
0.019 Air Products
II II
0.110 "
M ri
it n
0.091
n
0.019
n
n
Engelhard
Pellet**
Total Particulate
Emission Rates,
as Measured
Impactor
Stages +
Final Filter
0.011
0.005
0.009*
0.007
0.013
<0.001
0.036*
0.060
0.023
0.020
0.054
0.132*
gms/km
by
Total
Filter
0.034
0.020
0.010
0.051
0.149
0.106
0.043
0.163
0.123
0.105
0.258
0.152
** Runs 171-175 are sulfate storage runs.
-------
- 115 -
V. REFERENCES
(1) E. E. Wigg, "Fuel-Exhaust Compositional Relationships in Current
and Advanced Emission Control Systems," presented May 11, 1972
at Midyear Meeting of American Petroleum Institute's Division of
Refining, New York, New York.
(2) Cross, G. P., "The Effect of Fuel and Vehicle Variables on Poly-
nuclear Aromatic Hydrocarbon and Phenol Emissions," SAE Paper
720210, January 1972, Detroit, Michigan.
(3) M. Beltzer, R. J. Campion, and W. L. Petersen, "Measurement of
Vehicle Particulate Emissions," SAE Paper 740286, February-March,
1974, Detroit, Michigan.
(4) Work Statement of Request for Proposal DU-72-B407, Commerce Business
Daily, January 26, 1972.
(5) M. Beltzer, Environmental Health Perspectives, 10, 121 (1975).
(6) Bulletin No. 07169, "HoneyCombe Industrial Dehumidifiers,"
HoneyCombe Industrial Division, Gargocaire Engineering Corporation,
Amesbury, Massachusetts.
(7) Electronic Control Systems, Fairmont, West Virginia.
(8) Electric to Pneumatic Transducer, Model No. T5129, Fairchild
Industrial Products Division, Winston-Salem, North Carolina.
(9) Pneumatic Controller, Model and Size B-51XC4, Conoflow Corporation,
Blackwood, New Jersey.
(10) Dunham-Bush Corporation, West Hartford, Connecticut.
(11) Coolenheat Incorporated, Linden, New Jersey.
(12) H. Schlicting, "Boundary Layer Theory," New York, McGraw Hill Book
Co., Inc., pp. 504-5(1960).
(13) R. L. Bradow and J. B. Moran, "Sulfate Emissions from Catalyst
Cars-A Review," SAE Paper 750090, February 1975.
(14) K. Habibi, Env. Sci. and Technol., 4, 239 (1970).
(15) J. B. Moran and 0. J. Manary, Interim Report PB 196783, "Effect
of Fuel Additives on the Chemical and Physical Characteristics of
Particle Emissions in Automotive Exhaust," NAPCA, July 1970.
(16) Instruments for Measurement and Control of Relative Humidity,
Brochure B-ll and Form D-ll, Phys-Chemical Research Corporation,
New York.
-------
- 116 -
(17) Private communication, R. Bradow, EPA.
(18) L. S. Bernstein, "Statement on Automotive Sulfate Emissions to EPA
Hearings on Delay of the 1977 CO and HC Automotive Emission
Standards," January 29, 1975.
(19) M. Beltzer, e_t _al., "The Conversion of SC^ on Automotive Oxidation
Catalysts," SAE Paper 750095, February, 1975.
(20) R. J. Fedor, e£ al. , "Durability Experience with Metallic NO Catalysts,"
SAE Paper 741081, October, 1975. x
(21) Private communication, W. S. Briggs, Grace.
(22) F. Feigl, Spot Tests in Organic Analysis. 7th ed., Elsevier Pub-
lishing Company, 1966.
(23) K. Habibi, e_t _ali. , "Characterization and Control of Gaseous and
Particulate Exhaust Emissions from Vehicles," presented at APCA,
October 8-9, 1970.
(24) H. P. Schuchmann and K. J. Laidler, J. Air Poll. Control Assoc.,
22:52 (1972).
(25) H. H. Watson, Am. Ind. Hyg. Assoc. Quarterly 15, 21 (1954).
(26) S. Badzioch, J. Inst. Fuel, 33, 106 (1960).
(27) EPA, peronnel communication.
(28) G. S. Springer, "Engine Emissions, Pollutant Formation and
Measurement," p. 195, Plenum Press (1973).
(29) H. Goksrfyr and K. Ross, J. Inst. Fuel, 35:177 (1962).
(30) E. S. Lisle and J. Sensenbaugh, Combustion, 36:12 (1965).
(31) G. R. Gillespie and H. F. Johnstone, Chem. Eng. Prog., 51:74 (1955).
-------
- 117 -
APPENDIX A
ANALYTICAL METHODS
A.I Analytical Determination of Sulfate
In earlier in-house work on sulfate emissions, sulfate was
determined gravimetrically by a modification of the standard gravimetric
method for sulfate, ASTM Procedure 01099(1). This has been superceded
by a titrimetric procedure for sulfate using a color indicator.
Sulfonazo III £4,5-dihydroxy-3,6-bis(o-sulphophenylazo)-2,7 naphthalene-
disulfonic acidj. The procedure has been adapted from that of Budesinsky
and Krumlova(2).
The soluble sulfate collected by the filter in the exhaust
particulate sampler is leached from the filter with dilute nitric acid.
The leach solution is heated to boiling to drive off excess nitric
acid, filtered to remove insoluble material, passed through an ion-
exchange column to remove interfering cations, and then buffered
with methenamine to a pH of 3-4. The resulting solution is titrated
with barium perchlorate using Sulfonazo (III) as the indicator.
A.1.1 Reagents
The reagents used are as follows:
1. Barium perchlorate standard solution 0.01N
2. Barium perchlorate standard solution O.OOlN
3. Hexamethylenetetramine (57, aqueous)
4. Sulfonazo III indicator (0.1 g/100 ml HjO)
5. Ethyl Alcohol, absolute
6. Acetone
7. Nitric acid (2"/e aqueous)
8. Dowex 50 W-X8 cation exchange resin (50-100 mesh)
A.1.2 Tltratlon Apparatus
The following apparatus was used in the titrations-
1. Ion exchange column, 1 cm x 25 cm.
2. Burettes (at least 0.05 ml div)
3. Low range pH paper - J. T. Baker Dual-Tint pH 1.0-4.3.
A.1.3 Standardization of BaCClO^)? Solution
The barium perchlorate solution is standardized by titration
against previously standardized O.OlN sulfuric acid as follows:
(1) 5 mis of O.OlN sulfuric acid is pipetted into a 125-ml
Erlenmeyer flask.
-------
- 118 -
(2) 45 mis of deionized water and 2.5 mis 2% nitric acid
are added.
(3) Adjust the pH as described in the Procedure and titrate
with barium perchlorate solution.
(4) Calculate normality.
mis H^SO, x N H«SO,
N Ba2
A. 1.4 Detailed Titration Procedure
(1) Cut and place 1/4 sectionof filter in 100-ml beaker.
(1/2 filter can be used for lower levels of SO,).
(2) Add 3.0 mis of 2% nitric acid, wetting the filter section
completely.
(3) Add 20 mis of deionized water.
(4) Place small glass stirring rod in beaker and cover with
watch glass.
(5) Digest samples on hot plate and allow to boil for 5
minutes
(6) Cool beakers and filter liquid through glass wool into
the ion-exchange column containing ~7. 5 g of Dowex 50 W-X8 cation
exchange resin, collecting sample in 125 ml Erlenmeyer flasks.
(7) Wash beaker with 3 x 5 ml portions of deionized water.
Add washings to column. After each washing, squeeze liquid from the
filter by pressing it against the wall of the beaker with the stirring
rod.
(8) Place the flask on a hot plate and evaporate to approximately
5 mis .
(9) Adjust the pH of the remaining solution to pH 4 using
57, hexamethylenetetramine .
(10) Add 10 mis ethyl alcohol and 25 mis acetone to the flask.
(11) Add 3 drops Sulfonazo III indicator.
(12) Titrate with O.OlN barium perchlorate solution. (If
sulfate content is low, use 0.001N barium perchlorate.) If the sample
-------
- 119 -
requires more than 10 mis of barium perchlorate to reach the end point
the results are unreliable and should be discarded. Another portion
of filter should be treated as in steps 1-7. Solution should he col-
lected in 100 ml volumetric flask. An appropriate size aliquot is
taken and the test is continued with step 8.
A.1.4.1 Effect of Nitric Acid on Measurement of Sulfate
Because nitric acid is used as the leaching agent, several
experiments to ascertain the effect if any of nitric acid on the
determination of sulfate were carried out. The test matrix, shown in
the following table,shows that there is no effect of nitric acid on the
titration.
Table A-l
Comparative Titrations of Sulfate of
Samoles With and Without Nitric Acid
Sample
Contains
HN03
Yes
No
Yes
No
ml
Theory
5.0
5.0
5.0
5.0
0.012 N Ba(Cl04)2
to Titrate
Ac t ua 1
4.9
4.7
4.7
4.8
Ami
-0.1
-0.3
-0.2
-0.2
A. 1.4. 2 Precautions About Titration Procedure
The above procedure was arrived at after experimental work
identifying sources of error and the means to minimize or eliminate
these errors was worked out. Reliable results can be obtained if the
following precautionary measures are taken:
(1) Keep HN03 at minimum
(2) Keep water in sample at minimum
(3) pll is very critical f/4.0)
(4) Use blank for color comparison of end point
(5) Change Dowex frequently (approx. 3 samples)
(6) If sample is basic - adjust with Nitric Acid
For example, it was shown that not only is the ion-exchange
step necessary to eliminate interference, but that it is necessary to
insure that the capacity of the ion-exchange bed is not close to
exhaustion. It was also shown that it is necessary to use a new batch
of ion-exchange resin rather than a regenerated batch. Positive
deviations were obtained when titrating the effluent from a regenerated
ion-exchange bed. The results of the tests described above are shown in
Table A-2.
-------
- 120 -
Table A-2
Experiments Demonstrating Influence of
Ion Exchanger on Sulfonazo m End Points
Mis. Titration
Mis.
Blank
0.5
0.75
.00
.50
2.00
2.00
1.50
1.00
Blank
0.2
0.5
0.1
0.8
1.0
2.0
Theory
0.0
0.5
0.75
,00
.50
2.00
2.00
1.50
1.00
0
2.0
5.0
1.0
0.8
1.0
2.0
Actual
0.1
0.5
0.65
1.0
1.25
1.45
2.2
1.75
1.1
0.15
2.10
4.95
1.45
0.80
1.00
1.90
Ami
+0.1
0
-0.1
0
-0.25
-0.55
+0.20
+0.25
+0.10
+0.15
+0.10
-0.05
+0.45
0
0
-0.10
Same column for
all samples
0.012 N Ba(C104)2
New Dowex each
sample
0.012 N Ba(Cl04)2
0.0012 N Ba(C104)2
New Dowex
0.012 N Ba (C104)2
Blank
,1
,1
,2
,2
2.0
2.0
0
.0
.0
.0
.0
.0
0.25
2.
2,
2.
3.
1.
10
00
90
00
30
2.0
1.40
+0.25
+1.10
+1.00
+0.90
->-l.00
-0.7
-0.6
Regenerate Dowex with
1:5 HC1
0.0012 N Ba(Cl04)2
0.012 N Ba (C104)2
As shown above, the Dowex ion exchanger has to be changed
frequently, and that large errors result if one attempts to work with
a presumably regenerated ion exchanger. Satisfactory results can be ob-
tained if the Dowex resin is changed after every two to three determinations,
A. 1.5 Sulfate Determinations on Glass Fiber Filters
Spiked with Known Quantities of H2S04
A series of filters were spiked with known quantities of H2S04
using 1.000 N H2S04 and a 5 yl syringe and with 0.0112 N H2S04 solutions.
The filters were leached with water, the leach solution worked up for
-------
- 121 -
for analysis as discussed in Section A.1.4. Figure A-l shows a plot
of added sulfate versus sulfate recovered by titration. It can readily
be seen that analysis of sulfate on the filters is as reliable as
analysis of solutions containing known quantities of sulfate. The next
step was to determine if this method is workable with filters containing
actual auto exhaust since the presence of organic exhaust particulate
matter on these filters could possibly introduce substances which
interfere with the color change of the titrimetric procedure. To deter-
mine if such interferences existed, the procedure was then checked against
the gravimetric determination of sulfate on parallel filters from
actual vehicle test runs since the presence of organic materials would
have no effect on the latter determination.
A.1.6 Comparison of Titrimetric and Gravimetric
Procedures on ^ilters fro") Vehicle Tests
Comparisons were then made between the titrimetric and
gravimetric analytical procedures on particulate filters from actual
vehicle runs. The titrimetric analysis was carried out on quarter sec-
tions of the filters, the gravimetric on an entire parallel filter.
The particulate filters were generated from vehicles equipped with
pelletized and monolithic catalysts, operating on fuels of sulfur
levels ranging from 0.004 to 0.14 wt %. Both cyclic and steady state
test modes were used. The results are shown in Table A-3.
Table A-3
Comparison of Titrimetric and Gravimetric
S0,= Analyses on Parallel Filters
(Actual Vehicle Runs, Sample Data)
Run Type
40 mph, 1/2 hr.
1975 FTP
1975 FTP
40 mph, 1 hr.
1975 FTP
60 mph, 20 min.
Fuel
Sulfur, 7,
0.14
0.065
0.056
0.004
0.14
I
0.004
I
0.14
I
0.004
Catalyst
Type
Pelletized
Monolith
SO^ Emissions, g/mi.
Titrimetric Gravimetric
0.036
0.012
0.0099
0.004
0.306
0.296
0.176
0.053
0.023
0.029
0.259
0.294
0.265
0.009
0.011
0.011
Regression analysis on 26 comparison sets showed:
0.040
0.011
0.0081
0.004
0.287
0.288
0.173
0.061
0.020
0.020
0.239
0.253
0.247
0.007
0.008
0.008
Titrimetric SO
1.029 Gravimetric SO.
> . A. * ' ^ ^ tll.«VA.IIIt»kfcLW> I_J VS t
4 4
Standard Deviation = 0.01
0.00085
-------
- 122 -
Figure A-l
Recovery of Sulfate From
Spiked Glass Fiber Filter Samples
10.0
9.0
8.0
« 7.0
13
a! 6.0
*J
iH
£
"£ 5.0
*j
cd
I 4.0
a- 3.0
2.0
1.0
Ideal Sulfate
Recovery Line
2345678
y gins Sulfate/Filter by Titration
10
-------
- 123 -
A. 2 Sulfur Dioxide Determination
Sulfur dioxide in diluted automotive exhaust was measured
using a Thermo Electron Corporation (TECO Model 40) Sulfur Dioxide
Analyzer(3). This device operates on a pulsed-fluorescence UV
absorption principle as follows. A gas sample is submitted to a source
of pulsed ultraviolet light through a monochromatic filter. Sulfur
dioxi.de molecules energized to an excited state by the high intensity
light source, return to the ground state bv emitting a monochromatic
light, which passes through a narrow-band filter, and impinges upon the
light sensitive surface of a photomultiplier tube. The intensity
of this radiation is directly proportional to the SO- concentration.
This measurement method was chosen because of the following
reasons:
(1) It is more convenient than wet chemical, conductimetric, or
coulometric methods.
(2) Both continuous and integrated measurements of SO- in diluted
exhaust can be made.
(3) Measurement of S02 emission rates could be incorporated as part
of the gaseous emission measurements routinely obtained using
diluted exhaust collected by the CVS system.
The operating principle of the TECO analyzer is depicted schematically
in Figure A-2.
To eliminate the possibility of water adsorbing and condensing
in the sample chamber on the walls and optical filters, the water in
the sample stream was removed upstream to the TECO analyzer. Initially,
Drierite was used to remove the water but it was found that at the 5
to 10 ppm level of S02, the Drierite absorbed all the SO--
The water removal problem was solved by using the Permatube
Drying System(4) shown in Figure A-3. This system dries the sample
stream by passing it through a bundle of tubes which are permeable
to water but essentially impermeable to S02 Water is purged by
countercurrent flow of dry air or nitrogen. The effectiveness of the
permeable system in reducing the water level of a humid sample stream
below 10 ppm 1^0 while retaining the S02 in the sample has been
established by our Analytical Division. The Model PD-500-72 Perma Pure
Dryer according to the manufacturer (4) has the capability of taking a
feed having a 120°F dew point and extracting sufficient water at a 4 to
6 SCFH feed rate to reduce the dew point of the effluent to -25°F.
-------
Figure A-^ Principle of Operation
TECO S02 Instrument
PULSATING
ULTRAVIOLET
LIGHT
FILTER
SAMPLE
GAS OUT
SAMPLE GAS CONTAINING S02 IN
PHOTOMULTIPLIER
TUBE
ELECTRONICS
NJ
4S
-------
Figure A-3
Permatube Drying Systern
HIGH PRESSURE
WET FEED
INLET
j**- LOW PRESSURE WET PURGE GAS OUTLET
I /- SHELL HEADER
HEADER L PERMEABLE TUBE BUNDLE
LOW PRESSURE
DRY PURGE GAS
INLET
HIGH PRESSURE
DRY PRODUCT
OUTLET
EXPANSION VALVE
Ul
I
-------
- 126 -
Our own tests with dry [.802 *n ^2 anc* *n air] have shown
that no differences in TECO readings were obtained when the sample is
introduced directly into the analyzer, or when it passes through
the dryer prior to entry into the analyzer.
A millipore filter is used upstream to the dryer to prevent
any particulate matter from entering and eventually clogging the
dryer, and for that matter, from possibly entering and contaminating
the analyzer.
It has been found that C02, CO, and Q£ are strong quenching
agents, while N2 exhibits a negligible quenching effect. The
instrument response is therefore sensitive to background gas composition.
Absolute values of S02 concentrations necessitate calibration of the
instrument in a background representative of the sample to be analyzed.
For example, prior to a laboratory study on S02 conversion
as a function of oxygen concentration, it was necessary to assess the
effect of oxygen quenching(5). Various amples were made by preparing
bell jar mixtures containing 30 ppm S02, 12% C02» varied amounts of oxygen,
and nitrogen as the balance gas. Measurements of the SOo concentration
of these mixtures indicate an approximate 1 ppm reduction in instrument
S02 response for each 2% increment in oxygen concentration, as shown
below.
Table A-4
S02 Measurements at Indicated
Oxygen Concentrations(a)
Oxygen
Concentration
(%)
0
1
2
4
6
TECO S02
Response
(ppm)
29.7
28.8
28.4
26.8
26.2
(a) Basic Mixture, 30 ppm S02, 12% C0_, balance N_.
The quenching effects of CO and C02 was also measured using
mixtures of 30 ppm S02 in pure CO and C02 In C02, the response to
30 ppm of S02 was 1.7 ppm, that in CO only 8.5. Measurements were then
carried out on bell jar mixtures of 30 ppm of S02 in background air
containing different concentrations of CO, 02, C3Hg, and C02- The
results given below show that instrument response is sensitive to overall
concentration of quenching species. Therefore data obtained where the
total background concentration
-------
- 127 -
Table A-5
Composite Effects of C02, 02 and
CO on TECO SOp Response
Total Quencher
Mixture Species Concentration (%) Instrument
Composition [COJ + |pj + [CQl Response (ppm)
30 ppm S0_
1.42% 02
0.09% CO
0.051% H2 ^-U 28
445 ppm C-jHg
12.5% C02
30 ppm SO
4.78% 02
14.3% C02 23'A 23
4.33% CO
348 ppm C_H_
J O
of quenching species changes significantly from the calibration gas
quencher level should be corrected for the inherent changes in instrument
response.
For vehicle work, quenching effects are minor. Quenching by
exhaust O>2 and CO is negligible for a CVS air diluted sample due to
dilution. Although the oxygen concentration increases with dilution,
it presents a reasonably constant quench background and can be taken into
account by calibration of dilute S02 in air mixtures. Properly used,
the precision of this instrument is about 0.5 ppm SO,.
A.3 Carbon. Hydrogen, and Nitrogen Determinations
Carbon, hydrogen, and nitrogen was measured by gas chromatography.
A portion of the glass fiber filters was inserted into the combustion
tube of a Perkin-Elmer Model 240 C/H/N microanalyzer. A schematic
of the detection system of this device is shown in Figure A-4.
Combustion of the samples occurs in pure oxygen. The products
of combustion are carried into a reduction zone which includes: silver
tungstate on magnesium oxide, silver oxide and silver tungstate on
chromosorb P, silver vanadate, and silver gauze. The purpose of this
reduction zone is to insure that combustion is complete and that inter-
fering combustion products (such as 502) are removed. The gas leaving
the reduction zone contains only C02, H20, N2, and He.
-------
- 128 -
FIGURE A-4
PERKIN-ELMER MODEL 240 C/H/N MICROANALYZER
COMBUSTION
.REDUCTION
MIXING VOLUME
PRESSURE SWITCH
SAMPLE VOLUME
DETECTORS
TRAPS i
Simplified Diagram of Combustion Train and Analytical System
FROM
SAMPLE
VOLUME
H20 HP
SENS REF
C02 C02
SENS REF
H20 +
O
He+C0.,+
a
r-
I HjOTRAP I
| (RETAINS H20) |
I COjTRAP I
| (RETAINSCOj))
a
(He)
a)
N2
SENS
REF
FROM
He SOURCE
-------
- 129 -
These gases are flushed into a closed, spherical glass
mixing volume and additional helium added until the pressure reaches
1500 mm Hg. The contents of the mixing volume remain there for 90 sec.
in order to reach a homogenous composition. When mixing is complete,
the contents of the mixing volume expand through the sample volume
detectors and out to the atmosphere.
Three pairs of thermal conductivity cells, in series, are used
for detection - one pair each for water, carbon dioxide, and nitrogen.
The platinum filaments of each cell pair are connected differentially
in a bridge circuit so that any difference in the contents of the two
cells will result in an electrical signal.
A magnesium perchlorate trap between the first pair of cells
absorbs any water from the gas mixture before it enters the second cell
so that the signal obtained from the corresponding bridge circuit is
proportional to the amount of water removed. Likewise, an absorbing
trap between the second pair of cells results in a signal proportional
to the carbon dioxide removed. The last pair of cells detects nitrogen
by comparing the thermal conductivity of the remaining sample gas to
that of pure helium.
The normal sample size used with the C/H/N analyzer is 2 mg
and accuracy of 0.3% is obtainable. This places the minimum detectible
amount of C, H, and N at~>6/(g. Only a portion of the filter can be used
because of the small combustion tube in this unit. If 25% of the
filter were used the minimum detectible emission rate would be ~ 6 x 10"^
g/ml of C, H, or N on the 1975 FTP or-2.5 x 10~5 g/km of C, H, or N on
the 2 hr., 70 mph cruise mode.
It should be noted that the hydrogen measurement obtained by
this technique includes hydrogen present in the particulate in water
of hydration. The amount of water of hydration can be determined separately
using the Karl Fisher titration technique. It would not be justified
to determine water routinely by Karl Fisher titration and also deter-
mine total hydrogen by the semi-micro combustion technique. This is
because data we have collected in previous work(6) show that
most of the hydrogen in particulate is present in water of hydra-
tion. To then determine organic hydrogen as the small difference
between two large numbers would result in a highly inaccurate value.
-------
- 130 -
A. 4 Characterization of Specific compounds in Automotive
_ Exhaust Particulate __
A.A.I Bound Water
Bound water is determined by the Karl Fisher titration technique.
This technique makes use of Che fact that water enters many reactions such
as the redox reaction:
I2 + S02 + 2 H20 - > 2 HI + H2S04
If this reaction is carried out in a non- aqueous medium it can
be used to quantitatively determine water. The reaction actually used is
H2° + I2 + S°2 + CH3OH + 2 py > CH HS04 + 2 Py.HI
whose Py = Pyridine. The Karl Fisher reagent is prepared from anhydrous
methanol, anhydrous pyridine, iodine and sulfur dioxide. A small sample
of the filter is soaked in anhydrous methanol then titrated with the
Karl Fisher reagent to an end point determined by the appearance of excess
iodine.
The procedure used at Exxon is Based on ASTM E203(7). The
titration is carried out to an electrometric end point using a commercial
titration assembly in which the titration is automatically stopped
at the end point (8). The least detectible amount of water is about
10 Vgms, although accuracy will suffer if 100 ygms of H20 is not obtained.
If one-fourth of a filter is used for analysis, 100 ygms of H20 corresponds
to a water emission rate of 6.8 x 10~4 gms/km for a 1975 FTP.
A. A. 2 Organic Nitrogen Compounds
A. 4. 2.1 Nitrogenous Particulate
Chemical spot tests were carried out on particulate samples
generated from the 1975 FTP and 64 km/hr (40 mph) test runs for
nitrogenous particulate and non-sulfate sulfur containing particulate
matter. The samples analyzed were from runs with the unequipped
vehicle, and with the vehicle equipped with the catalysts that were
tested in the contract program. The spot tests used were adapted from
Feigl(8).
The sensitivity of many of these tests is such that low levels
of nitrogenous and non-sulfate particulate matter should be readily
detectible. Negative tests for a given compound or compound type
establishes the maximum emission rate possible based on the sensitivity
of the spot test, the mileage accumulated on the particular test run,
and the size of the filter portion used for analysis. Because of the
many analyses that were conducted on the particulate filters, only a
small portion (0.385 cm2) was selected for a given spot test. Thus, the
maximum emission rate (ERM) » in gms/km for a given organic compound based
on a negative test result is:
-------
- 131 -
ERM
DL = chemical detection limit in grams
A (km) = distance accumulated on the particulate in kilometers
F! = volume fraction of diluted auto exhaust sampled
F2 = fraction of active filter area used for the chemical
spot test
Obviously by varying Fj and F2 , the maximum emission rate can
vary over a wide range. The volume fraction of diluted exhaust sampled
Fj, is fixed by our sampling tunnel and probe dimensions consistent
with isokinetic sampling. Larger filter areas could be used for analysis
if the need arose. Presently 0.42% of the active filter area (0.39 cm2)
is used for each chemical spot test. Maximum emission rates based on a
filter area of 0.39 cm2 generally range from 10~5 to 10~3 gms/km for the
1975 Federal Test Procedure, and 10~6 to 10~3 gms/km for the 64 km/hr
one-hour cruise. As mentioned above, the filter area selected for testing
was based solely on practical considerations. The range of maximum
emission rates based on this area are generally considered insignificant,
unless some unusually toxic or reactive component was involved. Figures
A-5 and A-6 depict the analytical test scheme for what are considered to
be chemically logical, possible exhaust nitrogenous and sulfur (excluding
sulfate) containing exhaust components. The nitrogen compounds tested
for were:
nitroparaff ins, nitroaromatics
organic nitrates, nitrites, nitroamines, and nitrosamines
aliphatic and aromatic nitriles
A. 4. 2. 2 Organic Nitrogen Compounds
The detection method used is described in Feigl, pages 90-92.
This test is valid for any type of nitrogenous organic compound. The
detection limit is 0.02 to 0.03 fgm of nitrogen. Using a circular cut
of filter 0.39 cm2, the detection limit corresponds to emission rates
of 1 x 10-5 gtr.s/km for the 1975 FTP and 2.5 x 10~6 gms/km for the 64
km/hr, one-hour cruise. If necessary, still lower emission rates could
be determined by simply taking larger filter areas for analysis.
A. 4. 2. 3 Compounds Containing Nitrogen and
_ Oxygen Bonded Together _
The method used is described in Feigl, pages 93-94. The detection
limit is about 0.1 to 0.2/
-------
Figure A-5
Analytical Scheme for Nitrogen Compounds
in Auto Exhaust Particulate
Exhaust
Particulate
Organic
Nitrogen
Compounds
Inorganic Nitrogen
Compounds
NH4+, N02~, N03~
j,
Oxygenated
Nitrogen
Compounds
1
1
Aliphatic
and
Aromatic
Nitro
Compounds
1
Primary
Aliphatic
Nitro
Compounds
1
Aliphatic
and
Aromatic
Nitroles
W
Nitrates
Nitrites
Nitroamines
Nitrosamines
Aliphatic
Nitriles
J>
Aromatic
Nitro
Compounds
l*J
N)
-------
Figure A-6
Analytical Scheme for Sulfur Compounds
in Exhaust Particulate
Exhaust
Particulate
I
I
Organically Bound
di and Tetravalent
Sulfur(l)
1
Alkyl and
Aromatic Sulfonic
Acids(2)
Sulfates
fColorimetric or''
(^Gravimetric
f
Selenium Test
if di and Tetra-
valent Sulfur
Tests Positive
I
M
U)
I
Positive Se
Sulfur in
Presence of
Selenium
-------
- 134 -
Thus, negative tests for these compounds correspond to an upper
emission rate of about 2 x 10~4 gms/km for the 1975 FTP and 5 x 10~5 gins/
km for the 64 km/hr, one-hour cruise. The following compounds can be
detected:
C - Nitro compounds
N - Nitro compounds
C - Nitroso compounds
N - Nitroso compounds
Hydroxamic acids
Oximes
Azoxy and hydroxyl amine compounds
Nitrates
Nitrites
Nitramines
Amine Oxides
A.4.2.4 Aliphatic and Aromatic Nitro Compounds
The detection method used is described in Feigl, pages 295-297,
included tests for primary aliphatic nitrocompounds. The detection
limits for general nitrocompounds were about 0.5 to l/
-------
- 135 -
The detection method used for aliphatic nitriles is described
in Feigl, pages 265-266 is sensitive in 2.5 to 150 ygm range. These
detection limits correspond to an emission range rate of 10~3 to
6 x 10~2 gms/kra for the 1975 FTP, and 2.5 x 10~4 to 1.5 x 10~2 gms/km
for the 64 km/hr, one-hour cruise. Most of the aliphatic nitriles can
be detected 2 to 20 ygm range.
A.4.3 Organic Sulfur Compounds
A.4.3.1 Organically Bound Di-and Tetravalent Sulfur
The methods used are described in pages 82 and 85 in Feigl.
Compounds which contain di- and tetravalent sulfur are:
thiocarbonyls
thiols
sulfides (open and cyclic thioethers)
disulfides
thiocyanates
isothiocyanates
sulfoxides
sulfinic acids
The general test (pages 82-83) for the above compounds can
detect about 2 ygm quantities corresponding to a 1975 FTP emission rate
of 8 x 10" gms/km, and 2 x 10~* gms/km for the 64 km/hr, one-hour
cruise. This test does not distinguish between the above compounds.
Because selenium is reputedly present on the filters, the general test
procedure would be modified as described on pages 83-84 to eliminate the
possibility of obtaining a false positive result for di- and tetravalent
organic sulfur compounds.
A.4.3.2 Alkyl and Aromatic Sulfonic Acids
The test procedure used is described in pages 85-86 of Feigl
The detection limits are about 2.5 Vgms of material corresponding to a
1975 FTP emission rate of 1 x 10-3 gms/km, and 2.5 x 10-4 gms/km for
the 64.36 km/hour, one-hour cruise. Sulfates do not interfere with the
tests for sulfonic acids.
Table A-6 shows the averaged maximum emission rates based on
chemical detection limits for both organic nitrogen and organic sulfur
compounds.
-------
TABLE A-6
ESTIMATED AVERAGE MAXIMUM EMISSION RATES (gms/km)
AS DETERMINED BY DETECTION LIMIT OF SPOT TEST ON INDICATED VEHICLE TEST
Compound Type
Organic Nitrogen
Compounds with Nitrogen and Oxygen Bonded
Together
Aliphatic and Aromatic Nitro Compounds
Primary Aliphatic Nitro Compounds
Aromatic Nitro Compounds
Nitrates, Nitriles
Aliphatic and Aromatic Nitriles
Aliphatic Nitriles
Di- and Tetravalent Organic Sulfur Compounds
Alkyl and Aromatic Sulfonic Acids
1975 FTP
1 x 10"5
2 x 10~4
3 x 10~4
2 x 10~4
6 x 10~4
1.2 x 10~4
4.4 x 10"3
_3
4 x 10
8 x 10"4
1 x 10~3
64 km/hr
One-Hour Cruise
2.5 x 10~6
5 x 10~5
7.5 x 10~5
5 x 10~5
1.5 x 10~4
3 x 10"5
1.1 x 10"3
_3
1 x 10
2 x 10~4
2.5 x 10~4
I
M
U)
I
-------
- 137 -
A.5 Determination of Metallic Components of Exhaust Particulate
A.5.1 Emission Spectroscopy
A procedure was developed to measure the emission rate of
the metals listed below by emission spectroscopy:
calcium, aluminum, zinc, chromium, iron, copper, nickel,
lead.
Emission spectroscopy was chosen as the analytical technique not only
because of its high sensitivity, but because it alone of the most various
alternative analytical procedures considered, allows most of the metals
to be measured by a single analytical procedure carried out on a single
sample without resorting to separations.
Nickel and copper vehicular exhaust emissions have been deter-
mined in earlier work by differential pulse polarography(9). This
technique is extremely sensitive and in many instances can measure
metallic cations (in solution) in the ppb range. Differential pulse
polarography could also be extended to measure exhaust chromium,
iron, zinc and lead. Several sample preparations would be required
however prior to polarographic analysis since some of the metal
cations are best determined in alkaline medium, others in acidic
medium, etc. In addition this technique cannot be used to determine
calcium and aluminum, necessitating the use of two additional, and
separate analytical procedures.
This spectrochemical method is based on the fact that all
elements when vaporized and excited in an electric arc emit light
energy at a series of wavelengths characteristic of that element.
The emitted radiations for the sought for elements are separated by
a grating, isolated and focused on the cathode of a photomultiplier.
The photomultiplier transforms the radiant energy into electrical
energy which is stored on a condenser of extremely low leakage
rage. The charge on the condenser is related to the concentration
by means of standard samples. This method has been in use at Exxon
for some time in measuring trace metals in organic materials such as
polymers and rubbers, and in a wide variety of materials such as slags,
ashes, and minerals.
A.5.1.1 Preparation of Calibration Standards
Standards were prepared by spiking filters so that the levels
for each metal ranged from 0.45 to 4.5 ^gms/cm2. The spiking solutions
used were Matheson, Coleman and Bell Atomic Absorption 1000 ppm
-------
- 138 -
Standard Solutions. A separate set of standards containing 4.5 to
11.25 /fgmslcm2 were prepared for Pb, Fe, and Zn, since it was found
that the levels of these metals on the exhaust particulate filters
frequently exceeded 4.5^gms/cm2. Additional standards were prepared
to simulate the combination of metals likely to be present on exhaust
particulate filters. The surface concentrations of the metals in the
mixture ranged from 0.45 to 4.5/^gms/cm2. Samples high in Ni and Cu,
but low in other metals were also prepared. In all cases, recovery
was within +15% of the quantity added to the filter. An ashless
Millipore filter was used because of its high filtering efficiency,
and negligible metals background.
Sample electrodes are prepared using the following reagents:
(1) Glycerol - U.S.P.
(2) Alcoholic Mg(N03)2'6H20
?cA5 8m^!!0?)2l6!!2n Per liter of 95% Ethanol
150 mg CO(N03)2-6 H20 v
(3) Aviation mix carbon
54 gm graphite
6 gm lithium carbonate
The electrode is prepared as follows:
2
The spiked 44 cm Millipore filter is put into a 100 ml beaker,
to which is added 1 ml of glycerol, 0.5 ml of magnesium nitrate solution,
and 1 ml of concentrated sulfuric acid. The mixture is heated until
the dense white fumes of 803 cease evolving. The sample is placed
into a muffle furnace at 1000°F for one hour. This procedure is
repeated if ashing was not complete the first time.
The ash is mixed with 400 ml of a 10% lithium carbonate, 90%
carbon blend in a Wig L-Bug mixer, until a homogeneous mixture is obtained.
This mixture is pressed into a 0.25 inch diameter electrode at 8000 PSI
using an ARL power driven hydraulic briquet ting press with a carbide
lined mold assembly.
The finished pellet is inserted into a brace electrode holder
in the quantometer, the counter electrode a 2-inch x 0.25-inch diameter,
high purity graphite rod with a flat tip. The spectrometer used was
a direct reading ARL Quantometer(10). The excitation source is a voltage
spark of the ARL multi-source unit, Model No. 4700. High voltage
excitation having the following parameters is used:
-------
- 139 -
Primary Voltage 150
Discharges per cycle 4
Capacitance, iff. 0.007
Inductance, /,h 360
The exposure conditions are as follows;
Slit Width - primary 20/f
secondary 150//
Prespark 10 seconds
Exposure 50 seconds
The 50-second exposure is controlled by a constant amount of energy from
the internal standards.
The following analytical lines (AO), were used.
_ Element _ AQ
Li (Internal Standard) 6102
Ca 4303
Pb 2833
Cu 3274
Al 3944
Zn 3345
Cr 4254
Ni 3415
Fe 3021
Calibration curves are constructed by exciting the electrodes
prepared from the calibration standards (described above) by plotting
the spectral intensity versus concentration using linear coordinates.
The low standard and high standard are used to set the instrument
curve, and the curvature is established by the intermediate standards.
Figures A-7 to A-15 show the calibration curves.
The spectral intensity obtained from the excitation of the
electrodes from the samples are compared to those of the standards,
and the equivalent /fgm/cm2 obtained from the calibration curves. The
emission rate (ER) in gms/km of a given metal is obtained as follows:
O _£
., . i. _ Cfgms/cm ) x 10 gms^/gm x Filter Area
ER in gms/km - -*-* - -
where Akm is the distance in kilometers accumulated on the test and F
is the probe volume fraction sampling rate.
-------
- 140 -
Figure A-7
Calibration Curve for Nickel
150 Volts, ~45 Second Burning Time
100
80
t>o
c
H
O
(0
-------
- 141 -
Figure A-8
Calibration Curve for Aluminum
150 Volts, ~/45 Second Burn Time
100 -
5.0
Aluminum
-------
- 142 -
Figure A-9
Calibration Curve for Calcium
150 Volts, ~45 Second Burn Time
100
80
oo
e
H
a
n
0)
4-1
-------
- 143 -
Figure A-10
Calibration Curve for Copper
150 Volts, ^45 Second Burn Time
100
80
oo
H
O
CO
a
M
0)
60
§
Or
40
20
1.0
2.0
3.0
4.0
5.0
y
y^gms/cm , Copper
-------
- 144 -
Figure A-ll
Calibration Curve for Chromium
150 Volts,-^_45 Second Burn Time
100
80
00
H
-o
14
0)
4J
-------
- 145 -
Figure A-12
Calibration Curve for Zinc
150 Volts, *-45 Second Burn Time
100
80
oo
C
i-l
TJ
CO
60
§
o-
40
20
1.0
2.0 3.0
Vgms/cm , Zinc
4.0
5.0
-------
- 146 -
Figure A-13
Calibration Curve for Lead
150 Volts, ~-45 Second Burn Time
100
80
00
c
"S 60
(-1
0)
0)
3
o-
40
20
1.0
2.0
3.0
Lead
4.0
5.0
-------
- 147 -
Figure A-14
Calibration Curve for Iron
150 Volts, -^45 Second Burn Time
100
oo
a
CO
0)
4J
80
60
§
o-
40
20
1.0
2.0
3.0
4.0
5.0
/Cgms/ctn , Iron
-------
- 148 -
Figure A-15
Calibration Curve for Platinum
150 Volts, -^45 Second Burn Time
100 -
80 -
oo
c
CO
«S 60
(U
u
0)
c
CO
o-
40 -
20
5.0
2
cm , Platinum
-------
- 149 -
A. 5. 1.2 Assessment of Interaction. Effects on
_ Metal Determinations _
Since filters from vehicle test runs would invariably have
a combination of various metals or metal derived particulate matter,
it was necessary to determine if there were any interactions which
produced interference which invalidated the 0.45 to 4.5 /Vgm/cm2
calibration curves for any or all of the metal containing components.
Measurements were made with filters spiked with salts of Ca,
Pb, Fe, Cu, Al, Zn, Cu, Ni , and Ft to ascertain if major interferences
exist. The results (excluding Pt)are shown below in Table A-7. In
some of the mixtures several of the components were present at levels
below the minimum detection limit, and above the upper calibration
limit.
This test matrix had a two-fold purpose:
(1) To determine if spurious results for some metals would be obtained
because of high levels of other metal components.
(2) To determine if the presence of other metals would produce
interactions such that metals which were present at levels above
and/or below the calibration limits would appear to be at levels
within the calibration limits.
Table A-7 shows that there are no major interferences so that
each of the metals or their salts may be determined in the presence
of the others without a major error. The average recovery for each
metal within the calibration limits is about 86%.
Regression analysis for each of the metals showed:
Ca (found) = 0.88
Clfl
Ca (present) + 0.08 /^gins/cm
Al (gound) = 0.97
Fe (found) = 0.83
Al (present) - 0.07 /jgms/cm
Fe (present) - 0.35 ftgms/cm'
(4)
Cu (found) = 0.93
Cu (present) + 0.09/fgms/cm
Pb (found) = 1.01 /( Pb (present) - 0.039 y/gms/cn/
cn\£ »*
-------
- 150 -
2
(6) 482| Zn (found) = 0.93 x*82! Zn (present) + 0.129 -*gms/ cm
cm cm A1
2
(7) # Cr (found) = 0.89 4 Cr (present) - 0. 120 *gms/cm
CD/ Cmt /V
(8) £B2f Ni (found) = 0.85 ^f Ni (present) + 0.05 *gms/cm2
cm^ cm^ *
cm'
Regression analysis for the eight metals showed:
(any metal found) = 0.91-4^- (any metal present) + 0.07,482^
cm^ cm^
A. 5. 1.3 Effect of Presence of Chromium
_ on Platinum Determination _
It was shown however, that although platinum could be determined
by emission spectroscopy to the same sensitivity levels as the other
metals (Figure A-15), the presence of chromium causes appreciable positive
deviations for platinum. Table A-8 summarizes the experimental matrix
which demonstrates the interference for platinum by chromium.
Even though the sample contains no platinum, the quantometer
indicates that platinum would be present. Table A-8 shows that it is
the chromium which is responsible for the spurious platinum readings.
The platinum readings on the quantometer were essentially constant
for the same quantity of chromium despite a four- fold change in the
nickel level and a ten-fold change in the copper level. Figure A-16
shows that the false quantometer readings for platinum vary linearly
with the quantity of chromium present, but is not a function of other
metals such as nickel and copper. Platinum therefore was not determined
by emission spectroscopy, but by X-ray fluorescence. This method
is discussed in Section A. 5. 2 of this Appendix.
A. 5. 1.4 Calibrations for High Levels of
_ Iron, Zinc and Lead _
In the course of carrying out the program it was found that
iron, zinc, and lead, were frequently found at levels above 4.
cm2. Additional calibrations for these three metals were made at
filter loadings up to 11.25 /^gms/cm2. The higher loading calibration
curves for these metals are shown in Figures A-17 to A-19.
A. 5. 2 Platinum Analysis by X-ray Fluorescence
Platinum analysis on the glass fiber filters was performed
by X-ray fluorescence , since it was found that chromium Interfered with the
determination of platinum when using emission spectroscopy.
-------
- 151 -
200
150
0)
4J
100
50
Figure A-16
False Platinum Response of Quantometer
Due to Presence of Chromium
150 Volts, -2/45 Second Burn Time
0
I
50 100
False Pt Reading
150
-------
Figure A-17
Calibration Curve for Lead
(4.5 to 11.25 ygms /cm2)
150 Volts, ~45 Second Burn Time
100
80
H
o
a)
a
M
01
§
o-
60
AO
20 .
4.5 5.0
6.0
7.0
8.0
9.0
10.0
11.0
//gins/cm , Lead
-------
Figure A- 18
Calibration Curve for Iron
(4.5 to 11.25/fems/cm2)
150 Volts, ~-45 Second Burn Time
100
80
60
T>
CO
A
t-i
10.0
11.0
, Iron
-------
Figure A-19
Calibration Curve for Zinc
(4.5 to 11.25 yfems/cm2)
150 Volts,
Second Burn Time
100 _
oo
c
H
8
H
-------
- 155 -
TABLE A-7
EFFECTS OF PRESENCE OF OTHER METALS ON
DETERMINATION OF A SELECTED METAL (0.45 to 4.5 'tgm/cm? CALIBRATION CURVE)
Metals Determined
2
fgms/cm. added
"gms/cm found
Percent Recovery
fgms/cm_ added
/,gms/cm found
Percent Recovery
'gms/cnu added
"gins /cm found
Percent Recovery
'fgms/cm» added
'rgms/cm found
Percent Recovery
gms/cnu added
' gms/cm found
Percent Recovery
2
/(gms/cm_ added
/'gms/cm found
Percent Recovery
«gms/cnu added
//gms/cm found
Percent Recovery
2
Vgms/cnu added
/^gms/cm found
Percent Recovery
2
/(gms/cnu added
X'gms/cm found
Percent Recovery
2
,Vgms / cm_ added
/'gms /cm f o un d
Percent Recovery
Ca
0.25
<0.45
(a)*
1.01
1.00
99
1.52
1.65
109
2.02
1.65
82
2.53
2.35
93
3.04
2.60
84
3.54
3.15
89
4.05
3.90
96
4.55
3.85
85
0.51
0.50
98
Pb
0.51
0.45
88
1.01
1.20
119
2.02
2.30
114
2.53
2.35
93
3.54
3.60
102
5.06
>4.50
(a)
7.59
>4.50
(a)
8.60
>4.50*
(a)
10.63
>4.50
(a)
13.16
>4.50
(a)
Fe
0.51
0.70
137
2.02
2.10
104
4.05
4.00
99
5.06
4.25
84
6.58
>4.50
(a)
7.59
>4.50
(a)
9.11
>4.50
(a)
10.12
>4.50
(a)
11.64
>4.50
(a)
13.16
>4.50
(a)
Cu
0.25
^0.45
(a)
1.01
1.05
104
1.52
1.60
105
2.02
1.80
89
2.53
2.45
97
3.04
2.80
92
3.54
3.40
96
4.05
3.90
96
4.55
4.25
93
0.25
^0.45
(a)
Al
0.25
<0.45
(a)
1.01
1.05
104
1.52
1.65
109
2.02
1.80
89
2.53
2.50
99
3.04
2.80
92
3.54
3.35
95
4.05
3.95
98
4.55
3.90
86
0.51
0.45
88
Zn
0.25
<0.45
(a)
1.01
1.15
114
4.05
4.40
109
2.02
J.90
94
3.04
2.95
97
5.06
4.30
85
7.59
>4.50
(a)
10.63
>4.50
(a)
11.64
>4.50
(a)
13.16
> 4.50
(a)
Cr
0.25
<0.45
(a)
1.01
1.05
104
1.52
1.65
109
2.02
1.85
92
2.53
2.45
97
3.04
2.75
90
3.54
3.30
93
4.05
3.90
96
4.55
3.95
87
0.51
<0.45
~-88
Ni
0.25
<0.45
(a)
1.01
1.05
104
1.52
1.45
95
2.02
1.65
82
2.53
2.20
87
3.04
2.45
81
3.54
3.05
86
4.05
3.65
90
4.55
3.85
85
0.51
<0.45
88
*(a) The metal loading was either above the upper calibration limit (4.5>^gTns/
cm2) or below the detection limit (0.45 ,
-------
TABLE A-8
PLATINUM-CHROMIUM INTERFERENCE
Micrograms of
Indicated Metal
in Sample Quantometer Readings for Indicated Metal
Pt Ni Cr Cu
0000
50 0 0 0
200 0 00
0 0 50 0
0 0 200 0
0 200 50 50
0 50 50 5
Pt
0
25.5
100.0
17.0
71.0
19.5
17.5
Pb
__
0.0
0.0
Cu
40.5
4.0
Al
«
-3.0
-4.0
Zn
0
0
Cr
32.0
95.5
35.0
32.5
Ni
89.5
27.0
Ca
5.5
4.0
In
-------
- 157 -
The X-ray procedure involves exposing circular sections
of the exhaust particulate filter in the X-ray beam of a Phillips
Number 1220 X-ray spectrometer. An internal standard is made by
spiking one of these filters with 40 /rgm of platinum as an aqueous
solution. The platinum X-ray peak intensity of the two filters is
then compared and the platinum content of the sample filter determined.
Blank filters are run in every determination. The minimum detectable
level of platinum by this technique is about 0.35
The maximum possible emission rates based on this sensitivity
limit is:
5.6 x 10~5 gms/km for the 1975 FTP
and 1.55 x 10 gms/km for the 64.36 km/hr, one-hour cruise
-------
- 158 -
APPENDIX B
MODIFIED ANDERSEN IMPACTOR
A model 0203 Anderson Impactor was modified and adapted for
use withdrawing samples from the dilution tunnel. Sampling of the usual
1 CFM however meant that the opening of the sampling probe coupled to the
impactor would be only 5mm when sized to the flow development tunnel. A
probe opening this small is conducive to material sampling losses in the
probe. The recommended minimum probe diameter to prevent these losses
is 6.4mm(ll). Increasing the volumetric flow rate through the impactor
would allow longer probe openings to be used. However, the high pressure
drop through the impactor limits the volumetric flow rates and, therefore,
the probe dimensions that can be used in the flow development tunnel.
As a compromise, the flow rate used for sampling with the im-
pactor is 1.5 CFM corresponding to a probe opening consistent with isokinetic
sampling of 6.4MM. The probe was flared up to one inch ID, a half inch
beyond the probe opening. This probe was bent at right angles in the
tunnel so that it emerged from the tunnel bottom. It was necessary to do
this because there was insufficient space for the impactor to fit in with.
the filter housings at the tunnel end.
To obtain size distributions by weight, one mil thick stainless
steel shimstocks replaced the particulate collection plates normally used
in the Andersen Impactor. The standard collection plates weigh about 20
grams, which exceeds the 10 gram capacity of the Mettler microbalance used
for weighing. The shimstock was washed progressively in cyclohexane-toluene
mixture, alcohol, acetone, and then cleaned ultrasonically in an aqueous
detergent solution. The shimstock was then rinsed with distilled water to
remove the detergent, successively washed in alcohol and acetone and then
dried.
The cleaned shimstocks were kept in Fetri dishes in a constant
temperature - constant humidity room and weighed daily for four days. Ex-
pensive testing indicated that the weight change that would be incurred by
a shimstock during a vehicle run should be a reliable measure of the
weight of material deposited of a given particle size range. The average
weight variation of a clean unused shimstock over a four day interval was
only + Sugms.
Several tests were carried out under 64.km/hr and 96.km/hr cruises
using an oxidation catalyst equipped vehicle operating on a 0.046 wt %
sulfur fuel. These test conditions were chosen to determine the feasi-
bility of the modified impactor. Steady state cruises with a catalyst
equipped vehicle should allow sufficient material to be collected on the
Impactor stages to obtain a size distribution by weight. The total parti-
culate emission rates obtained with the impactor should be in agreement
-------
- 159 -
with those obtained from the parallel total filters. Lack of agree-
ment between the total particulate emissions obtained with the Impactor
and the total filters would mean that the Impactor modifications inter-
ferred with its functioning properly.
All seven stages of the Impactor were used for these test
runs, as was the absolute filter. This filter is from the same batch
as the 15CFM filters (Gelman Type A Glass Fiber Filter). The results
for each of the runs in terms of total particulate emissions and sulfuric
acid emissions is shown in Tables B-l and B-2.
TABLE B-l
Comparison of Impactor and Total Filters
64 km/hr, (40mph), one hour cruise vehicle
equipped with PTX-IIB oxidation catalyst
Fuel Sulfur, 0.046 wt. %
Farticulate Emission Rate
gins/km
Particulate
Type
Total
Sulfate
The agreement between the Impactor and the total filters is within 5%
for both total particulate and sulfate emissions. About 90% of the parti-
culate and all of the sulfate was less than one micron as shown below.
TABLE B-2
Distribution of Particulate in
Modified Anderson Impactor
gms/km
Particulate Sum of Absolute Shims plus
Type Shims (1-7) Filter Filter
Total 0.009 0.071 0.080
Sulfate (not detected) 0.034 0.034
As shown in Figure B-l, the partlculates above one micron were
log normally distributed. Similar results were obtained with the 96 km/hr
(60 mph) one hour cruise as shown in Table B-3.
Modified
Impactor
0.080
0.034
Total Filters
-ill ill
0.087 0.087
0.034 0.033
-------
- 160 -
FIGURE B-l
OXIDATION CATALYST
EQUIPPED VEHICLE
0.046% S FUEL
10.0
o
o
I-H
i.o _
Q
|
M
0.1
0 =64 kn/hr cruise, one hour, cold start
O =96 km/hr cruise, one hour, hot start
50 60 70 80 90 95 98 99 99.5 99.9
CUMULATIVE % MASS <" PARTICLE DIAMETER
99.99
-------
Modified
Impactor
0.128
0.060
Total Filters
(1) (2)
0.130 0.131
0.055 0.053
- 161 -
TABLE B-3
Comparison of Impactor and Total Filters
96 km/hr (40mph) one hour cruise
vehicle equipped with PTX-IIB
oxidation catalyst - Fuel Sulfur,
0.046 wt. %
Particulate Emission Rate
gins/km
Particulate
Type
Total
Sulfate
Again good agreement between the Impactor and total filters is obtained
with respect to total particulate and sulfate emissions is obtained.
Over 95% of the total particulate and effectively all of the
sulfate is less than one micron in diameter as shown in Table B-4.
TABLE B-4
Distribution of Particulate in
Modified Andersen Impactor
(96.54 km/hr cruise)
gins/km
Particulate Sum of Absolute Shims plus
Type Shims (1-7) Filter Filter
Total 0.004 0.124 0.128
Sulfate (not detected) 0.060 0.060
As in the previous case, the particulates greater than one micron in dia-
meter were log normally distributed, Figure B-l. Thus, it appears that at
least for type of steady state cruises in which the particulate emissions
are high, the data obtained with the modified Impactor are reliable. It
was found that the particulate matter on the shimstocks was difficult to
remove. Accordingly, new shimstocks were used for each run.
-------
- 162 -
APPENDIX C
EXHAUST SPLITTER
An exhaust splitter was designed and tested to determine if ex-
haust particulate could be collected at 32°C (90°F) under high speed
cruise conditions (96 to 113 km/hr). If only 25% of the raw exhaust from
a 350 CID, V-8 vehicle operating at 113 km/hr for example, this volume of
exhaust would be approximately equivalent to the average output of the
same vehicle under FTP conditions. In order to accurately measure the ex-
haust particulate emission rates, the ratio of the exhaust volume intro-
duced into the tunnel to that rejected must be constant and accurately
known.
The basic approach was to split the exhaust so that the ratio of
the volume flow rates of rejected or vented exhaust to that of exhaust
introduced into the tunnel would be 3 to 1 at all times on high speed cruise.
Figure C-l shows a schematic of the exhaust splitter system.
The raw exhaust as it emerges from the finned tube enters con-
centric pipes designed so that the peripheral laminar area (shaded cross
section in the schematic) is three times the area of the smaller central
pipe. That is the ID of the smaller central pipe designated as (CD) in
the schematic is 2 inches. The ID of the larger pipe, designated as AB
in the schematic is 4 inches.
To accommodate the hot wire anenometer probes, the larger pipe
turns away from the smaller concentric one and its diameter is reduced to
2-f3"inches, so that the area ratio of the pipes no longer concentrically
situated is still 3 to 1. Hot wire anenometers are placed in the middle
of the large pipe at the point where the diameter is 2"f3~ inches, and into
the middle of the two-inch pipe. The two probes, although in separate
pipes, are as close to each other as is physically possible so that both
would be operating in split raw exhaust streams having the same temperature.
Under these conditions, if the linear velocities of the sample streams in
each pipe are equal, the volume flow rate ratio in the pipes is 3 to 1.
Initial work using lab air rather than raw exhaust showed that
this concept was valid. Laboratory air was pulled into the dilution tunnel
by the CVS at total flows of 150 and 225CFM. The lab air entered the
tunnel via the diluent air treatment system (dehumidifier, filter and
chiller) and the injection leg of the exhaust splitter. No attempts were
made to dehumidify the air. Direct reading flowmeters capable of handling
large flows were inserted in each leg downstream to the anenometers.
The anenometers used were connected to a Datametrics Model 700-6 Anenometer
circuit(13).
-------
FIGURE C-l
SCHEMATIC OF EXHAUST SPLITTER
Dilution
Tunnel
Diluted
Exhaust
* c
->
IDEp = 3.46"
Vented Exhaust
to Variable
Speed Pump
Exhaust
Injector
To CVS and
Particulate
Filters
Hot Wire Anenometers
to
Da tametries Linear
Velocity Readout
2" ID
Raw Exhaust
=T Finned Tube 2" ID
U)
I
Tail Pipe
-------
- 164 -
The experimental test was carried out oppositely to how the
splitter would be used in practice. For a given total volume flow rate,
the flow in the vent leg was adjusted with a variable speed pumps until
the volumetric flow rate ratio was 3 to 1. The linear velocities in
each leg were indicated on the Datametrics Readout. Table C-l below
shows that the linear velocity results agreed to within about 4%.
TABLE C-l
Performance of Exhaust
Splitter on Lab Air
Corresponding Linear
Measured Velocities (ft/rain)
Flow Rate Datametrics
CVS (CFM) Readout
Setting Vent Inlet (Arbitrary Units) Actual ft/min
(CFM) Leg Leg Vent Inlet Vent Inlet
150 72.7 24.5 0.89 0.95 1111 1125
225 132.7 44.0 1.52 1.65 2029 2018
The procedure in an actual run would be to adjust the variable
speed pump until the linear velocities in the vent and inlet legs were equal.
No volumetric flow rate measurement would be made because it is doubtful
that any flow meter would function properly after exposure to hot corrosive
exhaust, and any flowmeter in the inlet leg could alter the quantity of
particulate matter entering the dilution tunnel. Table C-l shows that it
should not be necessary to measure the volumetric flow rates. All that
would be necessary would be to maintain equal linear velocities in leg.
Although Table C-l shows that this approach is promising, this
method has not been successful in actual runs with catalyst equipped vehi-
cles. Several anemometer probes have failed when exposed to hot raw ex-
haust from oxidation catalyst equipped vehicles. It is probable that
corrosion of the sensing wires due to exposure to hot sulfuric acid aerosol
is the cause. In several vehicle tests, the sensing wires were missing
after the run, or else was attached to only one binding post.
Another approach along the same basic idea was to measure the
linear velocities using Pitot tubes, and equalizing the velocities by ad-
justing the pressure drop in the vent leg using a variable speed pump.
The pressure drops were small and subject to rapid oscillations, making
equalization extremely difficult. Attempts to damp these oscillations were
not successful.
-------
- 165 -
APPENDIX D
BASIS OF SELECTION OF THE SULFUR AND NITROGEN
CONTAINING ORGANIC COMPOUNDS WHICH MIGHT
APPEAR IN AN AUTO EXHAUST
The rationale for selecting classes of nitrogenous and non-
sulfate sulfur compounds as possible exhaust components is based on known
chemical reactions which produce these compounds. Only those components
known to exist in vehicular exhaust, which can function as precursors
to compound types or as reactants involved in their production, are consi-
dered. Several examples will be considered in some detail.
Schuchmann and Laidler (14) have shown the existence of alkyl
nitriles in automobile exhaust, which are the products of reaction between
nitric oxide and alkyl radicals, i.e.,
RCH2' + NO ^ RCN + H20
Based on the above reaction, alkyl nitrites could also be a logical ex-
haust product as a result of reaction between nitric oxide and alkaxy
radical as shown below:
RO- + NO RONO
Scizinger and Dimitriades (15), have shown that nitroalkanes are
components of automobile exhaust. Nitroalkanes could conceivably be made
by reaction of alkyl radicals and N0_. However, it is not necessary to
invoke this reaction to account for nitroalkanes. Levy (16), has shown that
in the presence of nitric oxide,alkyl nitriles are convented to nitro-
alkanes .
Ter Hoar, et. al.(17), have reported the presence of nitrates in
exhaust particulates. Organic nitrates could be formed by reaction of
alkyl nitrites with peroxides as shown below(18):
RCH2ONO + R'OOH ^ R'OH + RCH ONO
-------
- 166 -
The absence of peroxides in end gas condensate as demonstrated
by Alperstein and Bradow(19) and the presence of alcohols (15) and nitrates (17)
in automobile exhaust may be the result of the above type of reaction.
Although the formation of the aromatic analogues of the nitrogenous com-
pounds listed is less likely than their aliphatic counterparts, tests for
the nitrogenous aromatic compounds were also carried out.
Arguments applied to the possible formation of nitrogenous exhaust
matter are applicable to the non-sulfate sulfur compounds. For example,
sulfinic acids could be produced by reaction of SO, and an aromatic species
as shown below (2):
Aromatic sulfonic acids could result from reaction of SO- and an aromatic
species as shown below (21):
There are several factors operating against the formation of
aromatic sulfonic acids in auto exhaust: The low concentration of SO- in
conventional vehicle exhaust, and the greatly reduced level of aromatic species
(organics in general) in the exhaust of an oxidation catalyst equipped
vehicle. However, if one grants the possibility of aromatic sulfonic acids,
the presence of sulfones is also possible by virtue of the following re-
action^):
R(£-S03H + R'^-H
Another possible mechanism by which sulfones may be formed is by the re-
action of SO- with a conjugated di-olefin as shown below(23):
R H H
Sulfur compounds such as thiocarbonyls, sulfides, and mercaptans
are possible only under reducing conditions. Should operating conditions,
over an oxidation catalyst become net rich, a number of S02 reduction pro-
ducts including H_S are then possible. This condition is unlikely unless
engine or system malfunctions occur. Should these malfunctions occur, H^S
could react with various reactive exhaust components such as ketones,
aldehydes, and olefins to produce thiocarbonyls and mercaptans as shown
below: (14) R, Rl
RC=fO + H-S > RC=S and possible polymers
RC=0 + H2S ^ RC=S
CPU .A- U C ^ /PU ^ PQH
\stlty T rind w \\ti\r..) -L»on
^ fc ^ j j
-------
- 167 -
Mercaptans could also possibly be formed by the reaction be-
tween alcohols present in exhaust and H.S as shown below (25):
ROH + H2S - ^ RSH and H20, although this is a
less likely route to mercaptans.
In situations where H.S is produced alkyl isothiocyanates may
be produced if notroalkanes are also present by virtue of the following
possible pathway (26,27).
RC-NHOH
RC-NHOH - ^ RNCO + H_0
RNCO + H2S -- 7> RNCS + H20
The occurrence of many of the organic sulfur compounds , parti-
cularly the thiocarbonyls , sulfides, and mercaptans, in auto exhaust how-
ever, is extremely unlikely for the following reasons. The operating con-
ditions favoring H_S formation (high catalyst temperature and oxygen de-
ficiency) do not normally occur in oxidation catalyst emission control
systems, so that H.S formation over the catalyst is unlikely unless engine
or system malfunctions occur (28). Even if H.S were produced, the formation
of a mercaptan by reaction of H.S with an alcohol becomes more unfavorable
with increasing temperature, precisely the conditions assuming oxygen de-
ficiency favorable for H.S formation. Thermodynamic calculations based on
Free Energy of Formation data obtained from Stull, et. al(29) show that in
the temperature range of 800 to 1200 F, mercaptans should not form.
The occurrence of nitrogenous and sulfur compounds in automobiles
would expected to be at most at trace levels. That they should be present
in automotive exhaust particulate is even more remote. For example, if
all of the nitrogenous additive was convented to all or any of the nitro-
genous compounds discussed, it can readily be shown that there is not
sufficient nitrogen containing additive to produce enough of these compounds
to co-exist as two phases (vapor plus liquid) at the particulate collection
temperature. Only the liquid form could be trapped as particulate, and
it cannot exist as a liquid under the test conditions.
Assume that an alkyl nitrile such as valeronitrile (CH_)_ -CH-
(CH2)_CN was an exhaust component. At the particulate collection temper-
ature 90F, the vapor pressure of this compound is 12mmHg. At a tunnel flow
rate of 450CFM (12,600 liters/min) , the minimum production rate of valero-
nitrile required to maintain the equilibrium vapor pressure calculated from
the ideal gas law is :
(12/760) atm (12600) lit/min
(365"K) 82x10-3 litatm mole-1 deg-1
= 6.65 moles /min
= 645 gms/min
-------
- 168 -
This production rate is many orders of magnitude greater than
that of a nitrogenous exhaust product derived from a nitrogenous additive
could possibly be. This applies to all the nitrogenous compounds tested
for. Therefore, if nitrogenous additives result in nitrogenous organic
compounds as exhaust components, they must exist as gaseous components
if they exist at all. The only ways nitrogenous particulate exhaust
compounds could exist would be if they were strongly chemadsorbed on
particulate matter, or if they survived as high molecular weight nitro-
genous components. It is unlikely therefore, that there is an effect of
nitrogenous additives on exhaust particulate emissions.
Using a similar argument, it can be shown that it is highly
unlikely that non-sulfate sulfur compounds would show up as exhaust parti-
culate. The negative tests obtained for the nitrogenous and non-sulfate
sulfur compounds in exhaust particulate substantiates the above discussion.
Coupling this discussion with the negative test results, it may
be concluded that there is no exhaust particulate derived from the ashless
nitrogenous additives used. It may also be concluded that regarding
sulfur containing particulate, sulfate is the overwhelmingly predominant
species and most likely only one capable of existing as particulate.
Although the previous discussion pertained to nitrogenous and
non-sulfate sulfur containing particulate matter, similar conclusions can
be drawn regarding the presence of many of these compounds as gaseous com-
ponents of exhaust. This would particularly apply to the non-sulfate
sulfur compounds, especially the divalent sulfur compounds. For example,
consider the formation of COS produced by the following reaction:
C02 + H2S -) COS + H20
In raw, undiluted automotive exhaust, the C02 and H20 partial pressure
are comparable, greatly exceeding any H2S present. Consequently, the
equilibrium constant for COS formation is the ratio of
Pcos PH20 _ Pcos
K = PH2S PC02 " PR2S
The value of K at temperatures ranging from 800°F to 1160°F
ranges from 2.1 x 10~6 to 1.1 x 10"7. Thus, the COS concentration can
only be a negligible fraction of the H2S concentration. Since H2S
formation is unlikely, and at most would exist at low levels for small
time intervals, COS could not be a component of automotive exhaust. Similar
types of arguments could be extended to other organic compounds containing.
di-valent sulfur.
-------
- 169 -
APPENDIX E
RAW DATA
E.I List of Raw Data Tables
Title
Table
E-l Gaseous Emissions - Unequipped Mileage Accumulation Vehicle
E-2 | - Unequipped Test Vehicle
E-3 [ - Engelhard Monolithic Oxidation Catalyst
E-4 - Engelhard Pelletized Oxidation Catalyst
E-5 - UOP (1) Monolithic Oxidation Catalyst
E-6 - Matthey-Bishop Monolithic Oxidation Catalyst
E-7 - Grace NOX Reduction Catalyst
E-8 - Gould NOX Reduction Catalyst
E-9 - Grace Pelleted Oxidation Catalyst
E-10 - UOP (2) Monolithic Oxidation Catalyst
E-ll - Air Products Pelletized Oxidation Catalyst
E-12 - Sulfate Storage Experiment
E-13 \f ~ Engelhard Monolithic Oxidation Catalyst
After Misfire
E-14 Metal Derived Particulate Emissions - Unequipped Mileage Accumulation
Vehicle Runs (1-15) and Unequipped
Test Vehicle Runs (16-30)
E-15 - Engelhard Monolithic Oxidation
Catalyst
E-16 - Engelhard Pelletized Oxidation
Catalyst
E-17 - UOP (1) Monolithic Oxidation
Catalyst
E-18 - Matthey-Bishop Monolithic
Oxidation Catalyst
E-19 - Grace Reduction Catalyst
E-20 - Gould NOX Reduction Catalyst
E-21 - Grace Pelletized Oxidation
Catalyst
E-22 - UOP (2) Monolithic Oxidation
Catalyst
E-23 - Air Products Pelletized
\|/ Oxidation Catalyst
E-24 - Sulfate Storage Experiment
E-25 Sulfate Emissions - Unequipped Mileage Accumulation Vehicle
E-26 - Unequipped Test Vehicle
E-27 - Engelhard Monolithic Oxidation Catalyst
E-28 - Engelhard Pelletized Oxidation Catalyst
E-29 - UOP (1) Monolithic Oxidation Catalyst
E-30 - Matthey-Bishop Monolithic Oxidation Catalyst
E-31 - Grace NOX Reduction Catalyst
E-32 - Gould NOX Reduction Catalyst
E-33 - Grace Pelletized Oxidation Catalyst
E-34 - UOP (2) Monolithic Oxidation Catalyst
E-35 \/ - Air Products Pelletized Oxidation Catalyst
E-36 - Sulfur Storage Experiment
-------
- 170 -
TABIE E-l
GASEOUS EMISSIONS
UNEQUIPPED MILEAGE ACCUMULATION VEHICLE
Test No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
70 (2)
" 75 FTP
0.110 75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
0.091 75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
Gaseous Emissions, gms/km
CO
8.76
[170.38]
7.54
5.90
8.58
9.09
[ ]
2.63
8.59
9.49
[169.92]
4.23
2.62
8.24
HC
1.23
[9.24]
0.417
0.05
1.57
1.38
[ ]
0.06
1.21
1.62
[24.43]
2.60
0.010
1.80
NO
A
0.86
[19.12]
0.61
1.76
0.97
1.02
[ ]
0.73
1.00
1.38
[2.93]
0.34
0.60
1.17
SO.
z
0.239
0.181
0.301
0.363
[4.47]
0.154
0.154
0.347
0.019% S = EPA furnished reference fuel
0.110% S = EPA reference fuel plus additive package
0.090% = High aromatic fuel plus additive package
75 FTP = 1975 Federal test procedure
Idle (1) = One hour idle
40 (1) = 40 mph (64 km/hr) cruise for one hour
70 (2) = 70 mph (112 km/hr) cruise for two hours
(Idle gaseous emissions, brackets, are in gms/hr)*
-------
- 171 -
TABLE E-2
GASEOUS EMISSIONS
UNEQUIPPED TEST VEHICLE
Test No.
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
0.110 75 FTP
Idle (1)
40 (1)
70 (2)
11 75 FTP
0.091 75 FTP
Idle (1)
40 (1)
70 (2)
" 75 FTP
Gaseous Emissions, gms/km
CO
6.33
[21.69]
3.15
2.32
6.84
6.23
[29.4]
3.09
1.72
6.28
7.13
[35.14]
1.92
00.61
6.61
HC
0.78
[10.85]
0.18
0.04
3.70
0.71
[7.06]
0.17
0.05
0.99
0.75
[8.56]
0.17
0.05
0.74
NO
0.97
[3.05]
0.28
0.86
0.78
0.77
[2.20]
0.29
0.86
0.85
0.84
[6.30]
0.43
0.54
0.84
SO,
2
0.048
[1.260]
[0.025]
[0.035]
0.076
0.284
[3.262]
0.202
0.167
0.295
0.318
[5.26]
0.160
0.136
0.301
0.019% S = EPA furnished reference fuel
0.110% S = EPA reference fuel plus additive package
0.090% = High aromatic fuel plus additive package
75 FTP = 1975 Federal test procedure
Idle (1) = One hour idle
40 (1) = 40 mph (64 km/hr) cruise for one hour
70 (2) = 70 mph (112 km/hr) cruise for two hours
(Idle gaseous emissions, brackets, are in gms/hr)*
-------
- 172 -
TABLE E-3
% Fuel
Test No. Sulfur
36 0.019
37
38
39
40
41 0.110
42
43
44
45
46 0.091
47
48
49
50
CASEOUS EMISSIONS
ENGELHARD MONOLITHIC OXIDATION
CATALYST EQUIPPED VEHICLE
Caseous Emissions, gms/km
Run Type
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
CO
3.26
[7.70]
0.05
1.18
1.45
[5.32]
0.20
0.024
2.03
1.40
[7.26]
0.28
2.01
HC
0.29
[4.45]
0.04
0.63
0.80
[5.62]
0.08
0.003
0.42
0.28
[6.10]
0.08
0.28
NO
x
0.91
[8.66]
0.15
0.74
1.20
[3.91]
0.52
0.19
0.88
1.33
[3.91]
1.04
1.31
so,,
-x-0
0
0
0
0
0.134
[2.55]
0.057
0.009
0.139
0.080
[2.14]
0.050
0.098
0.019% S = EPA furnished reference fuel
0.110% S = EPA reference fuel plus additive package
0.090% = High aromatic fuel plus additive package
75 FTP = 1975 Federal test procedure
Idle (1) = One hour idle
40 (1) = 40 mph (64 km/hr) cruise for one hour
70 (2) = 70 mph (112 km/hr) cruise for two hours
(Idle gaseous emissions, brackets, are in gms/hr)*
-------
- 173 -
TABLE E-4
GASEOUS EMISSIONS
ENGELHASD PELLETIZED OXIDATION
CATALYST EQUIPPED VEHICLE
Test No.
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
70 (2)
" 75 FTP
0.110 75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
0.091 75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
Gaseous Emissions, ems/km
CO
2.528
[0.81 ]
0.019
2.501
1.528
[7.506]
0.154
0.086
1.327
2.162
[4.676]
0.218
0.044
2.808
HC
0.217
[1.458]
0.016
0.224
0.349
[3.964]
0.075
0.029
0.176
0.324
[2.333]
0.089
0.008
0.219
NOX
1.370
[0.54 ]
0.008
1.318
1.229
[8.73 ]
0.601
1.581
1.013
1.194
[8.932]
0.740
3.111
1.171
SO 2
0.015
[0.0 ]
0.0
0.093
0.043
[0.544]
0.0
0.0
0.058
0.061
0.0
0.022
0.129
0.066
0.019% S = EPA furnished reference fuel
0.110% S = EPA reference fuel plus additive package
0.090% = High aromatic fuel plus additive package
75 FTP = 1975 Federal test procedure
Idle (1) = One hour idle
40 (1) = 40 mph (64 km/hr) cruise for one hour
70 (2) = 70 mph (112 km/hr) cruise for two hours
(Idle gaseous emissions, brackets, are in gms/hr)*
-------
- 174 -
TABLE E-5
Test No.
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
% Fuel
Sulfur
0.019
0.110
0.091
GASEOUS EMISSIONS
UOP(l) MONOLITHIC OXIDATION
EQUIPPED TEST VEHICLE
CATALYST
Gaseous Emissions, gins/km
Run Type
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
CO
2.652
[22.766]
0.129
0.174
1.770
1.742
[ 4.946]
0.119
0.121
2.124
1.800
[ 4.136]
0.132
0.147
1.863
HC
0.274
L11.416]
0.042
0.018
0.191
0.250
[ A. 277]
0.048
0.014
0.264
0.191
[ 4.158]
0.033
0.013
0.150
NOX
1.091
16.728]
0.694
1.955
0.927
1.079
[5.098]
0.505
0.118
0.622
1.277
[6.836]
0.706
3.570
1.305
S02
0.061
[0.0 ]
0.0
0.031
0.029
0.190
[o.o ]
0.031
0.117
0.186
0.074
[0.0 ]
0.043
0.107
0.004
0.019% S = EPA furnished reference fuel
0.110% S = EPA reference fuel plus additive package
0.090% = High aromatic fuel plus additive package
75 FTP = 1975 Federal test procedure
Idle (1) = One hour idle
40 (1) = 40 mph (64 km/hr) cruise for one hour
70 (2) = 70 mph (112 km/hr) cruise for two hours
(Idle gaseous emissions, brackets, are in gms/hr)*
-------
- 175 -
TABLE E-6
GASEOUS EMISSIONS
MATTHEY BISHOP MONOLITHIC OXIDATION
CATALYST EQUIPPED TEST VEHICLE
Test No.
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
0.019% S
0.110% S
0.090%
75 FTP
Idle (1)
40 (1)
60 (2)
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
60 (2)**
11 75 FTP
0.110 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
0.091 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
Gaseous Emissions,, gms/km
CO
1.373
[ 8.834]
0.200
0.427
0.959
1.035
[ 8.067]
0.267
0.555
2.663
1.040
[5.430]
0.288
0.549
2.087
HC
0.232
[ 5.584]
0.047
0.033
0.146
0.241
[ 6.361]
0.058
0.033
0.323
0.244
[4.061]
0.049
0.030
0.253
NOX
1.083
[11.524]
0.598
2.208
0.578
1.116
[ 7.020]
0.648
2.430
1.136
1.313
[8.381]
30.890
2.938
2.112
S02*
0.031
[ 0.961]
0.037
0.022
0.023
0.245
[ 3.694]
0.197
0.213
0.275
0.233
[2.960]
0.160
0.194
0.388
= EPA furnished reference fuel
= EPA reference fuel
= High aromatic fuel
= 1975 Federal test
= One hour idle
= 40 mph (64 km/hr)
= 60 mph (96 km/hr)
plus additive
plus additive
procedure
cruise for one
cruise for two
package
package
hour
hours
(Idle gaseous emissions, brackets, are in gms/hr)*
* S02 calibrated from S02 in air calibration curve (no correction factor was used)
** 60 mph (96.54 km/hr) supplants the former 70 mph cruise test runs
-------
- 176 -
TABLE E-7
GASEOUS EMISSIONS
GRACE NOX REDUCTION
CATALYST EQUIPPED VEHICLE
Test No.
96
97
98
99
100
101
102
103
10 A
105
106
107
108
109
110
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
60 (2)
11 75 FTP
0.110 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
0.091 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTp
Caseous Emissions, gms/km
CO
10.177
[42.206]
0.350
1.913
7.298
10.657
[98.550]
0.603
0.208
]0.439
10.828
[41.926]
0.474
0.350
14.262
HC
0.375
[4.19]
0.055
0.057
0.498
0.446
[11.804]
0.099
0.024
0.455
0.454
[13.640]
0.077
0.057
0.531
NO
2.006
[8.906]
1.469
3.175
.1.907
2.138
[10.530]
1.976
1.682
1.860
2.529
[7.873]
1.842
4.783
2.705
so,.
-------
- 177 -
TABLE E-8
Test No.
Ill
112
113
115
116
117
118
119
120
121
112
123
124
125
% Fuel
Sulfur
0.019
0.110
0.091
CASEOUS EMISSIONS
GOULD NO REDUCTION CATALYST
EQUIPPED VEHICLE
Gaseous Emissions, gms/km
Run Type
75 FTP
Idle (1)
40 (!)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
CO
12.560
[75.589]
0.131
0.006
8.102
J1.558
[5.195]
0.1.80
0.014
6.458
6.173
[9.050]
0.140
0.066
6.466
HC
0.582
[7.247]
0.055
0.003
0.285
0.430
[3.424]
0.046
0.005
0.297
0.452
[4.428]
0.038
0.023
0.327
NO
K
1.515
[1.205]
1.721
0.319
1.890
2.032
[6.134]
2.083
0.503
2.967
1.966
[6.588]
2.249
3.865
2.620
SO
0.119
[0.035]
0.024
0.004
0.053
0.290
[1.62]
0.139
0.020
0.271
0.243
[1.577]
0.107
0.125
0.242
0.019% S = EPA furnished reference fuel
0.110% S = EPA reference fuel plus additive package
0.090% = High aromatic fuel plus additive package
75 FTP = 1975 Federal test procedure
Idle (1) = One hour idle
40 (1) = 40 mph (64 km/hr) cruise for one hour
70 (2) = 70 mph (112 km/hr) cruise for two hours
(Idle gaseous emissions, brackets, are in gms/hr)*
Exhaust gas recycle and air pump disconnected
-------
- 178 -
TABLE E-9
Test No.
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
% Fuel
Sulfur
0.019
0.110
ii
0.091
CASEOUS EMISSIONS
GRACE PELLETIZED OXIDATION
CATALYST EQUIPPED VEHICLE
Gaseous Emissions, gms/km
Run Type
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
CO
1.563
[3.000]
0.116
0.051
1.739
1.519
[3.445]
0.103
0.048
0.966
1.274
[6.826]
0.278
0.063
2.053
HC
0.182
[4.212]
0.027
0.015
0.150
0.162
[3.726]
0.028
0.011
0.164
0.154
[4.039]
0.030
0.011
0.134
NO
1.188
[6.005]
0.686
1.788
1.215
1.304
[6.977]
0.016
1.887
1.323
1.332
[7.571]
0.813
2.801
1.412
S00
0.032
[0.000]
0.006
0.022
0.010
0.070
[0.389]
0.076
0.13]
0.131
0.072
[0.972]
0.055
0.005
0.08]
0.019% S = EPA furnished reference fuel
0.110% S = EPA reference fuel plus additive nackage
0.090% = High aromatic fuel plus additive package
75 FTP = 1975 Federal test procedure
Idle (1) = One hour idle
40 (1) = 40 mph (64 km/hr) cruise for one hour
60 (2) = 60 mph (96 km/hr) cruise for two hours
(Idle gaseous emissions, brackets, are in gms/hr)*
-------
- 179 -
TABLE E-10
GASEOUS EMISSIONS
UOP(2) MONOLITHIC OXIDATION CATALYST
EQUIPPED VEHICLE
Test No.
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
0.110 75 FTP
Idle (1)
40 (1)
60 (2)
" 75 FTP
0.091 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
Caseous Emissions, gms/km
CO
0.666
[2.862]
0.105
0.089
1.431
0.768
[4^.471]
0.098
0.070
0.653
0.805
[4.018]
0.103
0.065
1.227
HC
0.101
[3.845]
0.016
0.018
0.127
0.098
[4.439]
0.025
0.021
0.105
0.154
[4.374]
0.023
0.012
0.239
NO
x
1.231
[8.597]
0.776
2.877
1.150
1.303
[8.921]
0.770
1.946
1.316
1.270
[5.918]
0.829
2.574
1.345
son
0.008
[0.000]
0.000
0.018
0.028
0.046
[0.194]
0.045
0.110
0.146
0.094
[0.389]
0.061
0.005
0.187
0.019% S = EPA furnished reference fuel
0.110% S = EPA reference fuel plus additive package
0.090% = High aromatic fuel plus additive package
75 FTP = 1975 Federal test procedure
Idle (1) = One hour idle
40 (1) = 40 mph (64 km/hr) cruise for one hour
70 (2) = 60 mph (96 km/hr) cruise for two hours
(Idle gaseous emissions, brackets, are in gms/hr)*
-------
- 180 -
TABLE E-ll
GASEOUS EMISSIONS
AIR PRODUCTS PELLETIZED
OXIDATION CATALYST EQUIPPED VEHICLE
Test No.
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
0.110 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
0.091 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
Caseous Emissions, gms/km
CO
3.825
[4.838]
0.049
0.027
1.860
4.607
[4.126
0.109
0.041
1.012
1.089
[2.786]
0.160
0.049
1.421
HC
0.268
[3.996]
0.017
0.010
0.115
0.185
[2.754]
0.027
0.015
0.135
0.170
[2.970]
0.016
0.013
0.174
NO
J"t
1.113
[14.515]
0.945
1.211
0.849
0.840
[8.64]
0.352
1.021
0.854
1.241
[8.402]
0.948
2.024
1.172
SO
0.028
[0.000]
0.002
0.016
0.001
0.040
[0.000]
0.030
0.080
0.042
0.082
[0.184]
0.044
0.096
0.076
0.019% S = EPA furnished reference fuel
0.110% S = EPA reference fuel plus additive package
0.090% = High aromatic fuel plus additive package
75 FTP = 1975 Federal test procedure
Idle (1) = One hour idle
40 (1) = 40 mph (64 km/hr) cruise for one hour
60 (2) = 60 mph (96 km/hr) cruise for two hours
(Idle gaseous emissions, brackets, are in gms/hr)*
-------
- 181 -
TABLE E-12
GASEOUS EMISSIONS, TEST VEHICLE EQUIPPED WITH ENGELHARD
PELLETIZED OXIDATION CATALYST AFTER CATALYST WAS CONDITIONED
ON A 0.091% S FUEL FOR 3200 KM ON THE FEDERAL DURABILITY CYCLE
Test No.
171
172
173
174
175
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
60 (2)
" 75 FTP
Emission Rates, j>ms/km
CO
1.225
[3.283]
0.137
0.040
1.011
HC
0.192
[5.411]
0.042
0.014
0.193
NO
x
1.201
[10.033]
0.627
2.472
1.092
S00
0.050
[0.983]
0.016
0.088
0.077
TABLE E-13
GASEOUS EMISSIONS, TEST VEHICLE EQUIPPED WITH
ENGELHARD MONOLITHIC OXIDATION CATALYST*
Test No.
31
32
33
34
35
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
" 70 (2)
" 75 FTP
Emission Rates, gins /km
CO
0.77
[6.11]
0.22
0.15*
4.84
HC
0.70
[2.08]
0.050
0.010
0.92
NO
X
1.66
[6.98]
0.38
0.18
1.11
SO,
2
0.035
[1.54]
0.045
0.003
0.057
Temperature runaway due to misfire 19 minutes into the run resulting
in catalyst deactivation, compare runs 31 and 35. The emission rates
for Test No. 34 are presented on normalized basis.
A second catalyst of this type was conditioned and screened (Table E-3)
Runs 36-50.
-------
TABLE E-14
METAL DERIVED EXHAUST PARTICULATE EMISSIONS
BASE CASE RUNS WITH UNEQUIPPED MILEAGE ACCUMULATION VEHICLE RUNS (1-15)
AND UNEQUIPPED TEST VEHICLE RUNS (16-30)
Test
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Run
Type
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
% Fuel
Sulfur
0.019
0.110
0.091
0.019
0.116
0.091
EMISSION RATE, CMS /KM AS
Ca
0.00025
[<0.0008]
0.00003
0.00011
0.00016
0.00014
[0.0022]
0.00004
0.00001
0.00017
0.00014
[0.0012]
0.00002
0.00001
0.00009
0.00007
[0.0004]
0.00001
<6 x 10-6
0.00002
0.00005
[<0.0004]
0.00002
<6 x 10-6
0.00004
0.00007
[0.0004]
0.00001
<0. 00001
0.00002
Al
<0. 00005
[<0.0008]
<0. 00001
6 x 10-6
0.00006
0.00020
[0.0015]
0.00002
0.00001
0.00006
0.00006
[<0.0004]
<6 x 10-6
<0. 00001
0.00004
0.00007
[<0.0004]
<6 x ID'6
<6 x ID"6
<0. 00002
0.00004
[<0.0004]
<6 x 10-6
<6 x ID"6
<0. 00002
0.00004
[<0.0004]
<6 x 10~6
<6 x lO-6
<0. 00002
Zn
0.00035
[0.0008]
0.00010
0.00009
0.00064
0.00027
[0.0035]
0.00005
0.00003
0.00080
0.00027
[0.0006]
0.00002
0.00003
0.00040
0.00016
[0.0006]
0.00001
0.00001
<0. 00002
0.00007
[0.0004]
0.00001
<0. 00001
0.00006
0.00010
[<0.0004]
<6 x 10-6
< 0.00001
0.00007
INDICATED METAL*
Cr
0.00005
[<0.0008]
0.00003
<0. 00001
0.00005
0.00007
[0.0009]
0.00002
<0. 00001
0.00009
0.00020
[0.0006]
<6 x ID"6
<6 x 1(T6
0.00005
0.00007
[< 0.0004]
< 0.00001
<6 x 10-6
< 0.00002
0.00012
[<0.0004]
<6 x 10~6
<6 x 10-6
< 0.00002
0.00004
[<0.0004]
<6 x 10-6
<6 x ID'6
<0. 00002
Fe
0.00134
[0.00032]
0.00022
0.00015
0.00080
0.00022
0.0080
0.00022
0.00012
0.00132
0.00134
[0.0040]
0.00003
0.00008
0.00052
0.00121
[0.0037]
0.00009
0.00006
0.00004
0.00123
[0.0005]
0.00004
0.00004
0.00028
0.00091
[0.0018]
0.00002
0.00006
0.00031
Cu
0.00012
[<0.0008]
0.00002
<6 x 10-6
0.00016
0.00014
[0.0019]
0.00002
0.00001
0.00031
0.00027
[<0.0004]
<6 x 10-6
0.00002
0.00025
0.00047
[0.0009]
<6 x 10-6
0.00004
0.00002
0.00040
[0.0008]
0.00002
0.00001
0.00037
0.00021
[0.0008]
0.00002
0.00002
0.00039
Ni
<0. 00005
[<0.0008]
0.00001
<0. 00001
0.00004
0.00005
[0.0009]
0.00001
<0. 00001
0.00008
0.00019
[<0.0004]
<6 x 10-6
0.00001
0.00005
0.00008
[<0.0004]
<6 x ID"6
<6 x 10~6
<0. 00002
0.00009
[<0.0004]
<6 x 10-6
<0. 00001
<0. 00002
0.00004
[<0.0004],
<6 x 10~b
<6 x 10"6
<0. 00002
Pb
0.00043
[0.0008]
0.00011
0.00009
0.00042
0.00058
[0.0063]
0.00014
0.00006
0.00006
0.00087
[0.0122]
0.00010
0.00006
0.00049
0.00070
[0.0024]
0.00005
0.00004
<0. 00002
0.00062
[0.0069]
0.00021
0.00010
0.00042
0.00059
[0.0004]
0.00011
0.00009
0.00037
oo
ro
75 FTP = 1975 Federal Test Procedure
Idle (1) = one hour idle
40 (1) " 40 mph (64 km/hr) cruise for one hour
70 (2) = 70 mph (112 km/hr) cruise for two hours
* Bracketed numbers are idle emission rates of metals in gms/hour.
-------
TABLE E-15
METAL DERIVED EXHAUST PARTICULATE EMISSIONS
Toot*
ico u
No.
31
32
33
34
35
36*
37
38
39
40
41
42
43
44
45
46
47
48
49
50
%Fucl
C UC J-
Run Type Sulfur
75 FTP 0.019
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP 0.019
Idle (1)
40 (1)
70 (2)
75 FTP "
75 FTP 0.110
Idle (1)
40 (1)
70 (2)
75 FTP "
75 FTP 0.091
Idle (1)
40 (1)
70 (2)
75 FTP "
EMISSION RATE, GMS/KM AS INDICATED METAL*
Ca
0.00010
[<0. 00180]
0.00004
0.00021
0.00016
0.00010
[ 0.00180]
<0. 00003
0.00009
0.00013
0.00016
[ 0.00180]
0.00003
<0. 00002
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Al
>0. 00010
[ 0.00180]
<0. 00003
0.00079
0.00051
0.00029
[ 0.00400]
0.00005
0.00016
<0. 00010
0.00021
[<0. 00180]
0.00004
0.00003
<0.00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Zn
>0. 00033
[ 0.00180]
<0. 00003
0.00204
0.00202
>0. 00100
[ 0.01440]
0.00011
0.00027
0.00039
0.00100
[<0. 00180]
0.00016
0.00015
0.00048
0.00043
[ 0.00220]
0.00003
>0. 00024
0.00079
Cr
0.00013
[ 0.00180]
<0.00003
0.00031
0.00025
0.00016
[<0. 00180]
<0. 00003
<0. 00058
<0. 00010
0.00037
[<0. 00180]
0.00003
0.00004
<0. 00010
0.00019
[<0. 00180]
<0. 00003
0.00001
0.00011
Fe
0.00202
[ 0.03600]
0.00010
0.00440
0.00202
>0. 00200
[>0.0018 ]
0.00021
>0. 00058
>0. 00100
>0. 00202
[ 0.00320]
>0. 00028
>0. 00020
>0. 00100
>0. 00100
[ 0.00240]
0.00006
>0. 00012
>0. 00100
Cu
0.00051
[ 0.00920]
<0. 00003
0.00115
0.00092
0.00038
[<0. 00180]
<0. 00003
0.00008
<0. 00010
0.00075
[<0. 00180]
0.00005
0.00006
0.00045
0.00065
[<0. 00180]
<0. 00003
0.00003
0.00072
Ni
0.00010
[ 0.00180]
O.00003
0.00021
0.00022
<0. 00010
[<0.0018 ]
<0. 00003
<0. 00058
<0. 00010
0.00020
[<0. 00180]
0.00004
0.00004
<0. 00010
0.00020
[<0. 00180]
<0. 00003
<0. 00001
0.00015
Pb
0.00100
[ 0.0180 ]
0.00011
0.00440
0.00101
>0. 00100
[ 0.00680]
0.00015
0.00046
0.00056
0.00101
[ 0.00320]
0.00024
>0. 00020
>0. 00100
0.00100
[ 0.00400]
0.00004
>0. 00012
0.00085
oo
LJ
* Bracketed numbers are idle emission rates of metals in gms/hour.
+ Replacement PTX-IIB (Runs 36-50) after first PTX-IIB deactivated (Run 34) due to excessive temperature rise resulting from misfire.
-------
TABLE E-16
METAL DERIVED EXHAUST PARTICULATE EMISSIONS
Test
No.
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
% Fuel
Run" Type Sulfur
75 FTP 0.019
Idle (1)
40 (1)
70 (2)
75 FTP "
75 FTP 0.110
Idle (1)
40 (1)
70 (2)
75 FTP "
75 FTP 0.091
Idle (1)
40 (1)
70 (2)
75 FTP "
Ca
0.00010
[<0. 00180]
0.00003
0.00004
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00004
<0. 00010
0.00024
[ 0.00380]
0.00006
0.00002
0.00029
EMISSION
Al
0.00026
[<0. 00180]
<0. 00003
>0. 00028
>0. 00100
0.00046
[<0. 00180]
<0. 00003
0.00006
0.00016
0.00020
[ 0.00200]
<0. 00003
0.00001
0.00022
RATE, GMS/KM
Zn
0.00076
[ 0.00260]
0.00004
>0.00057
>0. 00200
0.00037
[<0. 00180]
0.00005
0.00012
0.00019
0.00027
[<0. 00180]
<0. 00003
0.00002
0.00075
AS INDICATED
Cr
0.00021
[<0. 01800]
<0. 00003
>0. 00028
0.00024
0.00028
[<0. 00180]
<0. 00003
0.00005
<0. 00010
0.00018
[<0. 00180]
<0. 00003
<0. 00001
0.00012
METAL*
Fe
>0. 00202
[>0. 01800]
0.00028
>0. 00057
>0. 00200
>0. 00202
[ 0.00760]
0.00018
0.00073
>0. 00100
>0. 00101
[ 0.00620]
0.00023
>0. 00010
>0. 00202
Cu
0.00025
[<0. 01800]
0.00004
>0. 00028
0.00059
0.00048
[<0. 00180]
<0. 00003
0.00010
0.00043
0.00037
[<0. 00180]
<0. 00003
0.00001
0.00078
Ni
0.00019
[<0. 00160]
0.00003
0.00026
0.00019
0.00026
[<0. 00180]
<0. 00003
0.00006
<0. 00010
0.00021
[<0. 00180]
<0. 00003
<0. 00001
0.00015
Pb
>0. 00100
[0.00860]
0.00016
>0.00057
>0. 00100
>0. 00202
[0.00480]
0.00015
>0. 00036
0.00050
0.00076
0.00200
0.00007
0.00003
0.00057
co
I
Bracketed numbers are idle emission rates in gins/hour.
-------
TABLE E-17
METAL DERIVED EXHAUST FARTICULAXE EMISSIONS
TEST VEHICLE EQUIPPED WITH UOP (1) MONOLITHIC OXIDATION CATALYST
EMISSION RATE, CMS /KM AS INDICATED METAL*
Test
No.
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
Run Type
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
% Fuel
Sulfur
0.019
11
II
11
11
0.110
11
It
II
II
0.091
ii
11
11
Ca
0.00025
[0.00240]
0.00005
0.00002
0.00015
0.00018
[0.00440]
0.00005
<0. 00010
0 .00020
0.00019
[0.00380]
0.00006
0.00007
0.00022
Al
0.00030
[ 0.00180]
<0. 00003
0.00002
0.00031
0.00032
[ 0.00640]
0.00003
0.00001
0.00018
0.00016
[<0.00180]
<0. 00003
0.00007
0.00021
Zn
0.00035
[<0. 00180]
<0. 00003
0.00008
0.00100
0.00048
[ 0.00280]
0.00004
0.00001
0.00022
0.00025
[<0. 00180]
<0. 00003
0.00016
0.00018
Cr
0.00015
[<0. 00180]
<0. 00003
0.00002
<0. 00010
0.00026
[ 0.00240]
<0.00003
<0. 00001
<0. 00010
0.00012
[<0. 00180]
<0. 00003
0.00008
<0. 00010
Fe
>0. 00101
[ 0.00740]
0.00010
0.00016
> 0.00202
>0. 00202
[>0. 01800]
0.00021
>0. 00008
0.00087
0.00202
[ 0.00280]
0.00016
0.00016
0.00085
Cu
0.00030
[<0.00180]
<0. 00003
0.00003
0.00060
0.00028
[ 0.00260]
<0. 00003
<0. 00001
0.00034
0.00030
[ 0.00180]
<0. 00003
0.00008
0.00038
Ni
0.00017
[<0. 00180]
<0. 00003
<0. 00001
<0 .00010
0.00027
[ 0.00260]
<0. 00003
<0. 00001
<0. 00010
0.00010
[<0. 00180]
<0. 00003
0.00008
<0. 00010
Fb
0.00059
[<0. 00180]
0.00004
0.00008
0.00053
0.00087
[ 0.00780]
0 .00007
0.00002
0.00029
0.00037
[ 0.00200]
0.00014
>0. 00008
0.00039
00
Ul
Bracketed numbers are idle emission rates in gms/hour.
-------
TABLE E-18
TEST VEHICLE
METAL DERIVED EXHAUST PARTICULATE EMISSIONS
EQUIPPED WITH MATTHEY-BISHOP MONOLITHIC OXIDATION CATALYST
EMISSION RATE, CMS /KM AS INDICATED METAL*
Test
No.
81
82
83
84
85+
86+
87
88
89
90
91
92
93
94
95
Run Type
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
% Fuel
Sulfur
0.019
II
II
II
11
0.110
II
II
If
II
0.091
II
II
It
It
Ca
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
[<0. 00180]
0.00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
0.00001
<0. 00010
Al
0.00012
[<0. 00180]
<0.00003
0.00002
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
0.00001
<0. 00010
Zn
0.00024
[<0. 00180]
<0.00003
>0. 00010
[<0. 00180]
0.00003
0.00008
0.00018
0.00013
[<0. 00180]
0.00007
>0. 00010
0.00020
Cr
<0. 00010
[<0. 00180]
<0. 00003
0.00001
[<0. 00180]
<0. 00003
0.00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Fe
>0. 00101
[ 0.01820]
0.00017
>0. 00020
[ 0.00360]
>0. 00030
>0. 00018
0.00095
>0. 00020
[ 0.00600]
0.00025
>0. 00020
>0. 00101
Cu
<0. 00010
[<0. 00180]
<0.00003
0.00004
[<0. 00180]
<0. 00003
0.00002
0.00030
0.00039
[<0. 00180]
<0. 00003
0.00003
0.00037
Ni
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
[<0. 00180]
<0.00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
0.00010
Pb
0.00514
[ 0.00300]
0.00014
>0. 00010
[ 0.00280]
0.00013
0.00009
0.00034
0.00048
[ 0.00240]
0.00004
>0. 00010
0.00029
I
I--
CO
* Bracketed numbers are idle emission rates in gms/hour
± Samples 85, 86 Submitted to EPA for Platinum Analysis
-------
TABLE E-19
KETAL DERIVED EXHAUST PARTICULATE EMISSIONS
TEST VEHICLE EQUIPPED WITH GRACE REDUCTION CATALYST
EMISSION RATE, CMS /KM AS
Test
No.
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
% Fuel
Run Type Sulfur
75 FTP 0.019
Idle (1)
40 (1)
60 (2)
75 FTP "
75 FTP 0.110
Idle (1)
40 (1)
60 (2)
75 FTP "
75 FTP 0.091
Idle (1)
40 (1)
60 (2)
75 FTP "
Ca
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00006
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Al
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
0.00010
[<0. 00180]
<0. 00006
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Zn
0.00025
[<0. 00180]
<0. 00003
0.00008
0.00045
0.00021
[<0. 00180]
<0. 00006
>0. 00010
0.00016
<0. 00010
[<0. 00180]
<0.00003
0.00005
0.00027
INDICATED METAL*
Cr
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00006
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Fe
0.00064
[ 0.00580]
0.00014
>0. 00009
>0. 00200
>0. 00100
[<0. 00180]
>0. 00056
>0. 00009
0.00028
0.00020
[ 0.00220]
0.00011
0.00005
0.00062
Cu
0.00016
[<0. 00180]
<0. 00003
<0. 00001
0.00025
0.00017
[<0. 00180]
<0. 00006
0.00002
0.00021
0.00016
[<0. 00180]
<0. 00003
0.00001
0.00037
Ni
<0.00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00006
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Pb
0.00016
[0.00200]
0.00005
0.00005
0.00046
0.00045
[0.00240]
0.00010
0.00006
0.00019
0.00025
[0.00300]
0.00007
0.00009
0.00036
I
M
oo
I
* Bracketed numbers are idle emission rates of metals in gms/hour.
-------
TABLE E-20
METAL DERIVED EXHAUST PARTICULATE EMISSIONS
TEST VEHICLE EQUIPPED WITH GOULD NOX REDUCTION CATALYST
Test
No.
Ill
112
113
114
115
116
117
118
119
120
121
122
123
124
125
% Fuel
Run Type Sulfur
75 FTP 0.019
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP 0.110
Idle (1)
40 (1)
60 (2)
75 FTP "
75 FTP 0.091
Idle (1) "
40 (1)
60 (2)
75 FTP
Ca
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0 .00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
0.00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
EMISSION
Al
0.00016
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
0.00002
<0. 00010
< 0.00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
RATE, CMS /KM
Zn
0.00012
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
0.00016
[<0. 00180]
<0. 00003
0.00006
0.00010
0.00022
[<0. 00180]
<0. 00003
0.00002
0.00020
AS INDICATED
Cr
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
METAL*
Fe
>0. 00100
[ 0.00400]
0.00006
0.00004
<0. 00010
0.00058
[<0. 00180]
0.00008
>0.00020
0.00038
0.00165
[ 0.00820]
0.00008
0.00040
0.00047
Cu
0.00030
[<0. 00180]
<0.00003
<0. 00001
0.00017
0.00010
[<0. 00180]
<0. 00003
0.00003
0.00024
0.00038
[<0. 00180]
<0. 00003
0.00002
0.00025
Ni
>0. 00202
[ 0.01040]
0.00016
0.00008
>0.00100
0.00047
[ 0.00260]
0.00005
0.00010
0.00103
>0. 00202
I 0.00680]
0.00008
>0. 00009
>0. 00101
Pb
0.00036
[ 0.00200]
0.00003
0.00006
0.00017
0.00026
[<0. 00180]
0.00002
>0. 00010
0.00022
0.00043
[<0. 00180]
<0. 00003
0.00002
0.00054
00
oo
Bracketed numbers are idle emission rates of metals in gms/hour.
-------
TABLE E-21
Test
No.
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
Run Type
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
% Fuel
Sulfur
0.019
0.110
0.091
METAL DERIVED EXHAUST PARTICULATE EMISSIONS
TEST VEHICLE EQUIPPED WITH GRACE PELLETIZED OXIDATION CATALYST
EMISSION RATE, GMS/KM AS INDICATED METAL*
Ca
0.00011
[<0. 00180]
<0. 00003
0.00003
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00010
<0. 00010
Al
0.00013
[<0. 00180]
<0. 00003
0.00003
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
0.00011
[<0. 00180]
<0.00003
<0. 00010
<0. 00010
Zn
0.00168
[<0. 00180]
0.00014
0.00046
0.00047
0.00018
[ 0.00300]
<0. 00003
0.00003
0.00011
0.00058
[<0. 00180]
0.00009
0.00004
<0. 00010
Cr
<0. 00010
[<0. 00180]
<0.00003
0.00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00010
<0. 00010
Fe
0.00246
[ 0.0026C]
0.00010
>0. 00046
0.00048
0.00172
[ 0.00360]
0.00005
0.00005
0.00076
0.00235
[ 0.01100]
0.00026
0.00006
0.00106
Cu
0.00019
[<0. 00180]
<0. 00003
0.00005
0.00019
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
0.00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00010
<0. 00010
Ni
0.00064
[<0. 00180]
<0. 00003
>0. 00009
0.00017
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00010
<0. 00010
Pb
0.00063
[<0. 00180]
0.00005
>0. 00023
0.00020
0.00021
[<0. 00180]
<0. 00003
0.00003
0.00012
0.00035
[ 0.00240]
0.00009
0.00002
0.00021
oo
SO
* Bracketed numbers are idle emission rates in gms/hour.
-------
TABLE E-22
Test
No.
141
142
143
144
145
146
147
148
149
150
151
152
153
154*
155
Run Type
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
% Fuel
Sulfur
0.019
0.110
0.091
METAL DERIVED EXHAUST PARTICULATE EMISSIONS
TEST VEHICLE EQUIPPED WITH UOP (2) MONOLITHIC OXIDATION CATALYST
Ca
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[ 0.00180]
0.00003
EMISSION RATE, GMS/KM AS INDICATED METAL*
Al
0.00010
[<0. 00180]
<0. 00003
0.00001
<0. 00010
0.00019
[ 0.00220]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
Zn
0.00086
[<0. 00180]
0.00005
0.00023
0.00048
0.00142
[ 0.00200]
0.00022
0.00003
0.00024
0.00024
[<0. 00180]
0.00003
Cr
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
Fe
0.00493
[ 0.00960]
0.00019
0.00046
0.00012
0.00246
[ 0.00920]
0.00027
0.00006
0.00214
>0. 00246
[ 0.01200]
0.00019
Cu
0.00025
[<0. 00180]
<0. 00003
0.00003
0.00036
0.00032
[<0. 00180]
<0. 00003
<0. 00001
0.00020
0.00030
[<0. 00180]
<0. 00003
Ni
0.00019
[<0. 00180]
<0. 00003
0.00004
<0. 00010
0.00017
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
Pb
[ 0.00180]
0.00006
0.00015
0.00040
0.00067
[<0. 00180]
0.00008
0.00002
0.00024
0.00036
[ 0.00300]
0.00005
\o
o
<0.00010
<0.00010
0.00013
<0.00010
0.00236
0.00026
<0.00010
0.00030
Bracketed numbers are Idle emission rates in gms/hour.
Filter badly fragmented.
-------
TABLE E-23
METAL DERIVED EXHAUST PARTICULATE EMISSION KATES
TEST VEHICLE EQUIPPED WITH AIR PRODUCTS PELLETIZED OXIDATION CATALYST
Test
No.
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
% Fuel
Run Type Sulfur
75 FTP 0.019
Idle (1) "
40 (1)
60 (2)
75 FTP "
75 FTP 0.110
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP 0.091
Idle (1)
40 (1) "
60 (2)
75 FTP "
Ca
<0. 00010
[<0. 00180]
<0. 00003
< 0.00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
0.00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
0.00001
<0. 00010
EMISSION
Al
0.00028
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
0.00005
0.00001
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
RATE. CMS /KM AS INDICATED METAL*
Zn
0.00111
[<0. 00180]
<0. 00003
0.00004
0.00024
0.00022
[<0. 00180]
0.00019
0.00001
0.00012
0.00019
[<0. 00180]
<0. 00003
0.00005
0.00012
Cr
<0. 00100
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
<0. 00010
[<0. 00180]
0.00003
>0. 00009
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Fe
>0. 00246
[ 0.00660]
0.00010
0.00015
0.00116
0.00154
[<0. 00180]
>0. 00068
0.00046
0.00235
0.00493
[ 0.01720]
0.00026
>0. 00023
0.00246
Cu
0.00025
[<0. 00180]
<0. 00003
<0. 00001
0.00017
0.00028
[<0. 00180]
0.00007
<0. 00010
<0. 00010
0.00015
[<0. 00180]
<0. 00003
0.00001
<0. 00010
Ni
<0. 00010
[<0. 00180]
<0. 00003
0.00001
<0. 00010
0.00016
[<0. 00180]
0.00008
>0. 00009
<0. 00010
<0. 00010
[<0. 00180]
<0. 00003
0.00001
<0. 00010
Pb
0.00065
[<0. 00180]
<0. 00003
0.00004
0.00026
0.00048
[<0. 00180]
0.00015
0.00001
0.00015
0.00030
[<0. 00180]
<0. 00003
0.00004
0.00032
Bracketed numbers are idle emission rates in gms/hour.
-------
TABLE E-24
METAL DERIVED EXHAUST PARTICULATE EMISSION RATES
TEST VEHICLE EQUIPPED WITH ENGELHARD PELLETIZED OXIDATION CATALYST
AFTER CONDITIONING ON 0.091% SULFUR FUEL FOR 6400 KILOMETRES ON FEDERAL DURABILITY CYCLE
Test
No.
171
172
173
174
175
Run Type
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
EMISSION RATE, CMS/KM
% Fuel
Sulfur
0.019
ii
11
II
"
Ca
<0. 00010
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Al
0.00017
[<0. 00180]
<0. 00003
<0. 00001
<0. 00010
Zn
0.00045
[<0. 00180]
<0. 00003
0.00003
< 0.00010
AS INDICATED
Cr
0.00021
[<0. 00180]
< 0.00003
<0. 00001
<0. 00010
METAL*
Fe
>0. 00246
[ 0.00300]
0.00008
0.00009
0.00125
Cu
0.00040
[<0. 00180]
<0. 00003
<0. 00001
0.00016
Ni
0.00029
[<0. 00180]
<0. 00003
< 0.00001
<0. 00010
Pb
0.00104
[<0.00180]
<0.00003
0.00002
0.00016
Bracketed numbers are idle emission rates in gms/hour.
-------
- 193 -
TABLE E-25
Test No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
SULFATE EMISSIONS
UNEQUIPPED MILEAGE ACCUMULATION
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
70 (2)
" 75 FTP
0.110 75 FTP
Idle (1)
40 (1)
70 (2)
" 75 FTP
0.091 "
Idle (1)
40 (1)
70 (2)
11 75 FTP
VEHICLE
Sulfate
Emission Rate*
gms/km
0.002
[0.005]
0.001
0.002
0.003
0.003
[0.027]
<0.001
0.005
0.002
0.002
[0.028]
<0.001
0.003
-------
- 194 -
TABLE E-26
Test No.
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
SULFATE EMISSIONS
UNEQUIPPED TEST VEHICLE
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
0.110 75 FTP
Idle (1)
40 (1)
70 (2)
" 75 FTP
0.091 75 FTP
Idle (1)
40 (1)
70 (2)
it 75 FTP
Sulfate
Emission Rate*
gms/km
0.001
[0.021]
<0.001
0.001
0.001
0.003
[0.021]
<0.001
0.002
0.002
0.002
[0.024]
0.001
0.002
0.002
* Numbers in brackets are idle emission rates in gms/hr.
-------
- 195 -
TABLE E-27
SULFATE EMISSIONS
TEST VEHICLE EQUIPPED WITH ENGELHARD
MONOLITHIC OXIDATION CATALYST
Test No.
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
70 (2)
" 75 FTP
0.110 75 FTP
Idle (1)
40 (1)
11 70 (2)
" 75 FTP
0.091 75 FTP
Idle (1)
40 (1)
70 (2)
11 75 FTP
Sulfate
Emission Rate*
gins /km
0.002
[0.103]
0.012
0.010
0.004
0.060
[0.048]
0.101
0.055
0.053
0.087
[0.028]
0.076
0.057
0.050
* Numbers in brackets are idle emission rates in gms/hr.
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- 196 -
TABLE E-28
SULFATE EMISSIONS
TEST VEHICLE EQUIPPED WITH ENGELHARD
PELLETIZED OXIDATION CATALYST
Test No.
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle
40 (1)
70 (2)
75 FTP
0.110 75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
0.091 75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
Sulfate
Emission Rate*
gms/km
0.003
[0.022]
0.001
0.027
0.002
0.008
[0.052]
0.104
0.103
0.029
0.016
[0.0 ]
0.078
0.046
0.006
* Numbers in brackets are idle emission rates in gms/hr.
-------
Test No.
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
- 197 -
TABLE E-29
SULFATE EMISSIONS
TEST VEHICLE EQUIPPED WITH UOP(l)
MONOLITHIC OXIDATION CATALYST
% Fuel
Sulfur
0.019
11
11
it
11
0.110
11
II
II
It
0.091
n
it
n
it
Run Type
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
70 (2)
75 FTP
Sulfate
Emission Rate*
gins /km
0.003
[0.021]
0.013
0.011
0.001
0.022
[0.011]
0.183
0.065
0.027
0.033
[0.034]
0.165
0.061
0.008
* Numbers in brackets are idle emission rates in gms/hr.
-------
- 198 -
TABLE E-30
SULFATE EMISSIONS
TEST VEHICLE EQUIPPED WITH MATTHEY BISHOP
MONOLITHIC OXIDATION CATALYST
Test No.
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
60 (2)
" 75 FTP
0.110 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
0.091 75 FTP
Idle (1)
40 (1)
" 60 (2)
11 75 FTP
Sulfate
Emission Rate*
gins /km
0.003
[0.0 ]
0.006
0.010
0.003
0.032
[0.0 ]
0.055
0.068
0.016
0.024
[0.0 ]
0.043
0.058
0.015
* Numbers in brackets are idle emission rates in gms/hr.
-------
Test No.
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
- 199 -
TABLE E-31
TEST
GRACE
% Fuel
Sulfur
0.019
ii
11
ii
it
0.110
II
II
II
II
0.091
ii
ii
ti
it
SULFATE EMISSIONS
VEHICLE EQUIPPED WITH
NO REDUCTION CATALYST*
Run Type
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
Sulfate
Emission Rate**
gms/km
0.002
[o.ooo]
0.002
0.001
0.001
0.004
[o.ooo]
0.065
0.027
0.005
0.001
[o.ooo]
0.043
0.024
<0.001
* Exhaust gas recycle and air pump disconnected.
** Numbers in brackets are idle emission rates in gms/hr.
-------
- 200 -
TABLE E-32
Test No.
Ill
112
113
114
115
116
117
118
119
120
121
122
123
124
125
SULFATE EMISSIONS
TEST VEHICLE EQUIPPED WITH
GOULD NO REDUCTION CATALYST*
J\
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
0.110 75 FTP
Idle (1)
40 (1)
60 (2)
11 75 FTP
0.091 75 FTP
Idle (1)
40 (1)
60 (2)
" 75 FTP
Sulfate
Emission Rate**
gms/km
0.002
[0.000]
0.002
0.006
<0.001
<0.001
[0.000]
0.044
0.039
0.003
0.001
[0.000]
0.034
0.040
0.000
* Exhaust gas recycle and air pump disconnected.
** Numbers in brackets are idle emission rates in gms/hr.
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- 201 -
TABLE E-33
Test No.
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
SULFATE EMISSIONS
TEST VEHICLE EQUIPPED WITH GRACE
PELLETIZED OXIDATION CATALYST
% Fuel
Sulfur
0.019
If
11
II
"
0.110
II
II
II
II
0.091
ii
H
ii
it
Run Type
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
Sulfate
Emission Rate*
gms /km
0.002
0.000
0.006
0.019
0.007
0.009
0.000
0.088
0.146
0.034
0.010
[0.047]
0.067
0.096
0.026
* Numbers in brackets are idle emission rates in gms/hr.
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- 202 -
TABLE E-34
SULFATE EMISSIONS
TEST VEHICLE EQUIPPED WITH
UOP(2) MONOLITHIC OXIDATION CATALYST
Test No.
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
0.110 75 FTP
Idle (1)
40 (1)
60 (2)
i 75 FTP
0.091 75 FTP
Idle (1)
" 40 (1)
60 (2)
" 75 FTP
Sulfate
Emission Rate*
gms/km
0.006
[0.025]
0.015
0.024
0.008
0.032
0.176
0.113
0.090
0.078
[0.022]
0.160
0.110
0.052
* Numbers in brackets are idle emission rates in gms/hr.
-------
- 203 -
TABLE E-35
SULFATE EMISSIONS
TEST VEHICLE EQUIPPED WITH AIR PRODUCTS
PELLETIZED OXIDATION CATALYST
Test No.
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
% Fuel
Sulfur Run Type
0.019 75 FTP
Idle (1)
40 (1)
60 (2)
11 75 FTP
0.110 75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
0.091 75 FTP
Idle (1)
40 (1)
60 (2)
ii 75 FTP
Sulfate
Emission Rate*
gms /km
0.014
[0.030]
0.012
0.017
0.004
0.032
[0.033]
0.096
0.054
0.023
[0.394]
0.103
0.075
* Numbers in brackets are idle emission rates in gms/hr.
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- 204 -
TABLE E-36
SULFATE EMISSIONS AFTER STORAGE
Test Vehicle Equipped With Engelhard
Pelletized Oxidation Catalyst After Conditioning
Catalyst for 3200 km on Federal Durability Cycle
Sulfate
Test No.
,2
171
172
173
174
175
Precision
% Fuel
Sulfur
0.019
it
ii
ii
ti
of Total
Run Type
75 FTP
Idle (1)
40 (1)
60 (2)
75 FTP
Particulate Emission
Emission Rate
gms/km
0.044
0.119
0.103
0.100
Measurements
As previously discussed in Section II. 2. 2. 4, two parallel
probes coupled to appropriate filters are required to serve as internal
checks on the particulate sampling system. Reliable, accurate exhaust
particulate emission rates can be obtained only if close agreement
between parallel filter increases are consistently obtained.
Regression of 172 of the program runs showed the following
filter correspondence:
AW =0.98 AWfi where
W^ and AWg are the weight gains of parallel filters
A and B respectively.
-------
- 205 -
APPENDIX F
REFERENCES USED IN THE APPENDICES
(1) Standard Method of Test for Water Soluble Sulfates in Paper
and Paperboard, ASTM D-1099.
(2) B. Budesinsky and L. Krumlova, Analytica Chimica Acta, 39, 375
(1967).
(3) Sulfur Dioxide Pulsed Fluorescent Gas Analyzer Model 40, Thermo
Electron Corporation, Valtham, Massachusetts.
(4) Instruction and Operation Manual PD 101, Perma Pure Dryer, Perma
Pure Products, Inc., Oceanport, New Jersey.
(5) M. Beltzer, R. J. Campion, J. Harlan, and A. M. Hochhauser, "The
Conversion of SO Over Automotive Oxidation Catalysts," SAE Paper
No. 750095, Automotive Engineering Exposition, Detroit, Michigan,
February 24-28, 1975.
(6) Standard Method of test for Water Using Karl Fisher Reagent,
ASTM D203.
(7) Aquatest II Coulometer, Photovolt Corporation, New York, New York.
(8) F. Feigl, Spot Tests in Organic Analysis, 7th Edition, Elsevier
Publishing Company, 1966.
(9) M. Beltzer, R. J. Campion, and W. L. Petersen, "Measurement
of Vehicular Particulate Emissions," SAE Paper No. 740286,
February 25-March 1, 1974.
(10) Applied Research Labs, Sunland, California.
(11) R. L. Dunn, Plant Engineering, 15, 91 (1971).
(12) PVC Varea-Meter, Cat. File 520.210, Wallace and Tiernan Division,
Pennwalt Corp., Belleville, N.J.
(13) Model 700-6 Anemometer, Bulletin No. 537-700-6-P Datametrics,
Subsidiary of I.T.E. Imperial Corporation, Wilmington, Mass.
(14) H. P. Schucmann and K. J. Laidler, J. Air Poll. Control Assoc.,
22., 52 (1972).
(15) D. E. Seizinger and B. Dimitriades, ibid, 22_, 47 (1972).
(16) J. B. Levy, Tnd. and Eng. Chem., 48. 762 (1956)
-------
- 206 -
(17) G. L. Ter Haar, £t al. , J. Air Poll. Control Assoc., Z2, 39 (1972).
(18) N. V. Sidgwick, The Organic Chemistry of Nitrogen, p. 5, New Edition,
Revised and Rewritten by T. W. J. Taylor and W. Barker, Oxford
University Press, 1942.
(19) M. Alperstein and R. Bradow, Trans. SAE, J75.. 7*7 (1967).
(20) R. M. Hann, J. Am. Chem. Soc., 57, 2166 (1935).
(21) L. Lieserson, e_t _al. , Ind. and Eng. Chem., 40, 508 (1948).
(22) G. Fouque and J. Lacroix, Bull. Soc. Chim. France, 33. 180 (1923).
(23) 0. Grummit, A. E. Ardis , and J. Pick, J. Am. Chem. Soc., ^70, 5167 (1950),
(24) Kirk-Othmer, Encyclopedia of Chem. Technology, 2nd edition, V. 19,
p. 378 (1969).
(25) A. Binz and L. H. Pence, J. Am. Chem. Soc., 61, 3134 (1939).
(26) H. B. Hass and E. F. Riley, Chem. Rev., 32, 395 (1943).
(27) H. L. Yale, Chem. Rev., _33, 209 (1943).
(28) G. J. Barnes and J. C. Summers, "Hydrogen Sulfide Formation Over
Automotive Oxidation Catalysts," Presentation to The Society of
Automotive Engineers, February 24-28,11974, Detroit, Michigan.
(29) D. R. Stull, E. F. Westrum, Jr., and G. C. Sinke, "The Chemical
Thermodynamics of Organic Compounds, John Wiley and Sons, Inc., 1967.
-------
207
TECHNICAL REPORT DATA
(Please read Jiiilnirtioiiit on the rci etsc before completing]
1 REPORT NO.
EPA-650/2-75-054
3 RECIPIENT'S ACCESSION-NO
4 TITLE ANDSUBTITLE
Particulate Emissions From Prototype Catalyst Cars
5 REPORT DATE
May 1975
6. PERFORMING ORGANIZATION CODE
7. AUTHOR
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