EPA-460/3-74-022
STUDY OF POLYNUCLEAR
AROMATIC HYDROCARBON
EMISSIONS FROM HEAVY DUTY
DIESEL ENGINES
Prepared by
R. S. Spindt
Gulf Research and Development Company
P.O. Drawer 2038
Pittsburgh, Pennsylvania 15230
Contract No. 68-01-2116
EPA Project Officer:
R. E. Maxwell
Prepared for
Coordinating Research Council, Inc.
30 Rockefeller Plaza
New York, New York 10020
and
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Mobile Source Air Pollution Control
Emission Control Technology Division
Ann Arbor, Michigan 48105
July 1974
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This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are available
free of charge to Federal employees, current contractors and grantees,
and nonprofit organizations-as supplies permit-from the Air Pollution
Technical Information Center, Environmental Protection Agency, Research
Triangle Park, North Carolina 27711; or, for a fee, from the National Technical
Information Service, 5285 Port Royal Road, Springfield, Virginia 22161.
This report was furnished to the Environmental Protection Agency by
Gulf Research and Development Co. , Pittsburgh , Pa . , in fulfillment of
Contract No. 68-01-2116. The contents of this report arc reproduced herein
as received from Gulf Research and Development Co. The opinions, findings,
and conclusions expressed are those of the author and not necessarily
those of the Environmental Protection Agency. Mention of company or
product names is not to be considered as an endorsement by the Environmental
Protection Agency.
Publication No. EPA-460/3-74-022
11
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FIRST ANNUAL REPORT
ON
POLYNUCLEAR AROMATIC CONTENT OF HEAVY DUTY
DIESEL ENGINE EXHAUST GASES
Submitted to The
Environmental Protection Agency
Contract No. 68-01-2116
And The
Coordinating Research Council, Inc.
CRC-APRAC Contract No. CAPE-24-72(l-73)
731-CD003
For Period
Ending July 1, 1974
By
R. S. Spindt
Gulf Research & Development Company
P. 0. Drawer 2038
Pittsburgh, PA 15230
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TABLE OF CONTENTS
Page
LIST OF TABLES iii
LIST OF FIGURES iv
ABBREVIATIONS v
PERSONNEL 1
I. SUMMARY 2
II. INTRODUCTION 4
III. EXPERIMENTAL 6
A. Analytical Procedures 6
B. Bench Studies to Validate Sampling Techniques 6
C. Engine Studies 10
IV. RESULTS 13
A. Exhaust Sample Collection Development 13
B. Application of Radiotracers 17
C. Analysis of Diesel Fuels 22
D. Engine Repeatability Studies 28
E. Additional Engine Studies 30
F. Comparison of Exhaust PNA and Fuel PNA 33
G. Comparison of Gasoline and Diesel PNA Emissions 36
H. Analysis of Gaseous Emissions 38
V. CONCLUSIONS 40
VI. REFERENCES 41
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ii
TABLE OF CONTENTS - CONTINUED
APPENDIX A - ANALYTICAL PROCEDURES 42
I. PNA HYDROCARBONS IN DIESEL FUEL 42
A. PNA Concentration 42
B. Thin Layer Separation 45
C. Cellulose "Prep" Plate 45
D. Cellulose Separation 46
E. Recovery 47
II. DIESEL EXHAUST GAS ANALYSIS 49
A. Chromosorb 102 49
B. Lines 49
C. Filter Paper 49
D. PNA Concentration 51
III. PHENOL ANALYSIS 53
A. Preparation of Phenol Concentrate by Caustic Extraction..53
B. Total Phenol Analysis 54
1. Color Development 54
2. Calculations 54
3. Application of Total Colorimetric Phenol Method 55
C. Chromatographic Analysis 55
D. Methods Comparison 55
APPENDIX B - Diesel Engine Operating Procedures 61
APPENDIX C - Gaseous Emissions Summary 63
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iii
LIST OF TABLES
Table No. Title Page
1 Measurement of BaP Recovery Using Chromosorb-102 9
2 Engine Studies of PNA Recovery 14
3 Analysis of Radiotracer and UV Results,Exp.ll 19
4 Engine Productd BaP 21
5 Recovery of Injected BaP 23
6 Survey Fuel Inspection Data 26
7 PWA Content of Diesel Fuels ug/kg 27
8 13-Mode Test Repeatability 29
9 PNA Recovery in Double Length 13-Mode Cycle Test 31
10 PNA Emissions From The Smoke Cycle 32
11 Average PNA Emissions From Four 13-Mode Cycles 34
12 Comparison of PNA Found With Fuels 2-5 And 2-16 35
13 Comparison of Exhaust PNA to PNA in Fuel 37
14 PEA Emissions From Diesel and Gasoline Engines 38
15 Gaseous Engine Emissions 39
A-l PNA Recovery-Alumina, Neut., 2.5$ Water Deactivated.... 44
A-2 PNA Recovery Study - No. 2 Fuel Oil 48
A-3 Total Phenols 57
A-4 Gas Chromatographic Operating Conditions 58
A-5 Gas Chromatographic Separation of Phenols 59
C-l Gaseous Emission Summary - 13-Mode Cycle 63
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iv
LIST OF FIGURES
Figure No. Fa
1 System for Validating PKA Collection Efficiency 7
2 Chromosorb-102 Trap 8
3 Proportional Sampling System 12
4 PNA Collection Systems 15
5 Standardized Sampling System 24
A-l Diesel Fuel PNA Separation Procedure 43
A-2 Exhaust Gas Sample Preparation 50
A-3 Exhaust Gas Sample PNA Separation 52
A-4 Gas Chromatograph of Phenols in Diesel Exhaust 56
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ABBREVIATIONS
APRAC - Air Pollution Research Advisory Committee
Anth - Anthracene
BaA - Benz(a)anthracene
BaP - Benzo(a)pyrene
14
C BaP - Radioactive Benzo(a)pyrene
BeP - Benzo(e)pyrene
BghiP - Benzo(g,h,i)perylene
Chry - Chrysene
DDAD - Detroit Diesel Allison Division
Fluo - Fluoranthene
10 - Isooctane
M-Anth - Methyl Anthracene
PNA - Polynuclear Aromatic Hydrocarbons
Phen - Phenanthrene
Pyr - Pyrene
TLC - Thin Layer Chromatography
V-V - Volume/Volume
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PERSONNEL
1.
Supervisory Project Group
Mr. Roger Bascom - Chairman
Mr. C. R. Begeman
Mr. D. S. Gray
Mr. R. J. Hames
Mr. M. Malbin
Mr. R. E. Maxwell
Dr. S. S. Hetrick
Dr. Margaret Griffing
Dr. H. K. Newhall
Dr. J. M. Perez
Cummins Engine Company
General Motors Research Laboratories
AMOCO Oil Company
Detroit Diesel Allison Division,
General Motors Corporation
Shell Development Company
Environmental Protection Agency
Mobil Research and Development
Ethyl Corporation
Chevron Research Company
Caterpillar Tractor Company
Gulf Research & Development Company Personnel:
Dr. R. S. Spindt - Project Manager
Mr. J. C. Mulac, Jr. - Senior Project Engineer
Mr. J. G. Berry, Jr. - Project Engineer
Mr. M. S. Norris - Senior Research Chemist
Mr. E. D. Hill - Research Chemist
Mr. E. S. Dorinsky - Technician
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2.
I. SUMMARY
The first phase of a CRC/EPA sponsored study of polynuclear
aromatic (PNA) and phenolic hydrocarbon emissions from diesel engines has
been completed by Gulf Research & Development Company. The first year's
effort was concentrated on validation of the sample collection and
analytical techniques and a survey of the PNA content of U.S. diesel fuels.
A collection system consisting of a precooler, a glass fiber
particulate filter, and a Chromosorb-102* trap was used to collect PNA1s
from diesel exhaust. PNA's are removed from the collection system by
solvent washing and soxhlet extraction, concentrated, and analyzed by thin
layer chromatography. Total phenols are analyzed by the 4-amino-antipyrene
procedure.
Attempts to validate the sample collection system using C
tracers were not successful. It is hypothesized that PNA's injected into
the exhaust (i.e., tracers) are largely destroyed by reactions with other
exhaust components, while engine-generated PNA's on or within soot particles
survive these reactions. Radio tracers also indicate that PNA-destroying
reactions occur even after collection and extraction from the sample
system. Similar losses of PNA's do not occur with synthetic exhaust.
The fuel analyses showed that ASTM 1-D diesel fuels are nearly
free of PNA compounds. PNA levels in ASTM 2-D diesel fuels ranged from
near zero to values that reach the average concentration reported in motor
gasolines.
*Chromosorb-102 is a registered trademark of Johns-Manville, Inc.
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Work has been started to determine the effect of operating
conditions on PHA emissions and to establish the repeatability of the
overall procedure. Future work will concentrate on measurement of PNA
emissions from other types of diesel engines and on identifying the effects
of specific operating conditions, blowby, deposits, lube oil, and fuels.
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4.
II. INTRODUCTION
Concern for air pollution has shifted from major pollution
sources, first subjected to control measures, to include those of lesser
magnitude as the major sources have come under control. Diesel engine
exhaust is still a minor factor in pollution in the United States. But
because the diesel engine produces both smoke and odor in the exhaust,
attention to this problem area is justified.
Polynuclear Aromatic Hydrocarbons (PNA) do not appear to occur
naturally in the environment but have been associated with combustion
/ -i P w (i }
processes/ ' Ray and Long^ ' state that PNA is associated with soot
(2)
formation and inefficient combustion. Bailey, et al states that PNA
in diesel engines is associated with overfueling.
(5}
A Public Health Servicev ' study indicated that hand fired coal
burning combustion sources are the most important source of BaP emissions
in the United States. Much lower emissions were estimated for all other
combustion sources including motor vehicles.
An important investigation of the automotive vehicle contribution
to BaP levels in the atmosphere has been completed by Colucci and Begeman. '
They showed that vehicular contributions to total PNA levels could account
for between 5 and 42/0 based on correlations with lead measurements. In
another study, these authors^ ' showed that BaP in the fuel can survive the
(6)
combustion processes in a gasoline engine (up to 36^). Gross^ in a study
for the CRC-APRAC, showed that PNA emissions from gasoline engines were
influenced by (a) emission control systems, (b) PNA in fuel, and (c) oil
consumption rate.
^Numbers in parenthesis designate References at end of report.
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5.
As a result of the extensive PNA studies that have been made
on the gasoline engine and the relatively little work that has been done
on the diesel engine, the EPA and CRC-APRAC, in the fall of 1972, agreed
to fund a project to investigate PNA in diesel exhaust gases. The project
was awarded to Gulf Research 8= Development Company with a starting date
of June 29, 1973.
The scope of work for this project envisioned a two-year program
with specific items clearly spelled out. The eight items included are as
follows:
1. Demonstrate and validate the sample collection and
analytical techniques.
2. Survey a number of fuels and select a baseline fuel.
3. Measure PNA emissions from selected (7) engines.
4. Measure PNA emissions by operating mode.
5. Determine PNA emissions with fuels of high and low
PNA content.
6. Evaluate deposit effects on PNA emissions.
7. Determine the accumulation of PNA in the oil.
8. Evaluate effect of exhaust gas recirculation.
Only the first four items were to be included in the first year's
contract. Tasks 3 and 4 were not completed under this contract due to the
increased expenditure required to resolve problems encountered in Task 1.
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6.
III. EXPERIMENTAL
A. Analytical Procedures
We chose to determine polynuclear aromatic hydrocarbons (PEA)
and phenols by a separation technique that includes liquid solid column
chromotography and thin layer chromotography. Details of the procedures
are given in Appendix A.
It was anticipated that the engine exhaust sample would be
collected using a filter and a chromosorb-102 adsorption trap. ' This
material is known to adsorb hydrocarbons readily. Simple elution with
benzene was expected to recover the FNA quantitatively from the chromosorb
for further separation.
B. Bench Studies to Validate Sampling Techniques
To test the efficiency of the proposed trapping system for
PNA, a heated gas flow system was constructed as shown in Figure 1. The
construction of the sampling trap is shown in Figure 2. Air or nitrogen
gas at 3 CFM (5 m3/hr.) heated to an exit temperature of 350°F (177°C),
was spiked with benzo(a)pyrene using a motor driven syringe. Five jug Bap
in 1 ml. of isooctane was introduced into the gas stream over a 2-hour
period, except for runs B8-10.
Table 1 lists the results of these tests for several operating
conditions.
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FIGURE I
SYSTEM FOR VALIDATING PNA COLLECTION EFFICIENCY
Heating Coil
Chromosorb.
102 Traps
Water
Saturator
Motor Driven Syringe
For Injecting BaP
Thermocouple
D
Dry Gas
Flow Meter
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Fl GURE 2
CHROMOSORB 102 TRAP
.S.S. Pressure Cyl.
End Cap
-Screen Assemblies
100 Mesh Welded piston Ring
3" S.S. Tube
(3"O.D. x - Wall)
-Half of |- NPT
Collar
3" Marman
Flange (4 Req'd.)
3" S.S. Tube
(3"O.D. x JL wall)
CD
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9.
TABLE 1
MEASUREMENT OF BaP RECOVERY USING CHROMOSORB-102
Test
B-l
B-2
B-3
B-4
B-5
B-6
B-7
B-8
B-9
Gas'1'
Temp.
300 °F
300 °F
300 °F
300 °F
350 °F
350 °F
350 °F
350 °F
350 °F
Added Components
Water Vapor
Water Vapor
Water Vapor
Phenol in 10 + Water Vapor
m-Cresol in 10 + Water Vapor
Preload trap with 5 ug BaP
Preload trap
Carrier Recovery Efficiency %
Gas BaP Phenol
N2 89.
W2 89.
W2 74.
N 85.
N2 ?6'
N2 90. 0
N 96. 23$ (in
water trap)
Air 91.
Air + 87.
720 ppm NO
B-10 350°F Preload trap inject 1 ml ether
+ diesel fuel (10/0)
Air + 85.
900 ppm NO
(1) Temperature measured at BaP injection point.
In each case, a second chromosorb trap was installed in the system
but no BaP was ever found on it. Therefore, Chromosorb-102 is an excellent
scavenger for BaP. The temperature of 350°F (177°C) was chosen because at
lower temperature, some of the BaP is found in the lines. A recovery of
is quite satisfactory.
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10.
Phenol or m-cresol at 100 mg/ml was added with the BaP in two
experiments. In neither case, did the presence of these compounds interfere
with the recovery of BaP.
The three runs with air as the carrier gas showed that no BaP is
flushed from the Chromesorb-102 trap. However, the addition of NO to the
air seems to indicate a possible degradation of the recovery. Since these
runs were all of short duration (15 minutes), it is possible that longer
exposure would have increased the loss.
In these experiments, the syringe, lines and traps are separately
washed with benzene and the separate solutions concentrated with 1 ml
hexadecane. The final hexadecane solution was then analyzed using ultra-
violet spectroscopy. Since only one PNA was present, no separation
technique was required, except when ether and diesel fuel were added.
C. Engine Studies
A Detroit Diesel Allison Division (DDAD) model 3-53 automotive
engine was available in this laboratory for our initial studies. The engine
test cell instrumentation included equipment for measuring: (1) engine torque
and speed, (2) fuel consumption, (3) gaseous emissions (CO, HC, WO, NO ,
A
C00, and 0_), and (4) smoke. The optical portion of the smokemeter was
t» Lt
mounted at the end of the exhaust stack approximately 25 feet (7.6 m) from
the engine. Two sample probes were installed in the engine exhaust pipe
approximately 10 feet (3m) from the engine. One probe supplied exhaust
sample for the standard gaseous emission measurements and the second probe
supplied sample for PNA analysis. A variable rate proportional sampler was
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11.
modified to permit varying the ratio of sample gas volume to total exhaust
gas volume. This alteration allows the use of the device on any size
engine. Figure 3 is a diagram of the exhaust sampling system.
Two cycles were specified for evaluation in this work. These
(8)
cycles are given in the Federal Register in complete detail. Appendix
B describes the speed load pattern with time that was used. The 13-mode
Federal Cycle for standard exhaust pollutant analysis was used for
preliminary studies. This cycle can be sampled at constant flow rate,
proportional to the engine exhaust flow because it is a series of steady
state conditions. The other cycle is the Federal Smoke Cycle composed of
transient acceleration and lugging modes. Since this composite transient
cycle must be repeated approximately one hundred times, a DATA-TRAK controller
was programmed to duplicate this cycle. This cycle controller with the
variable rate proportional sampler makes the collection of a constant fraction
of the exhaust relatively easy.
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FIGURE 3
PROPORTIONAL SAMPLING SYSTEM
Participate
Filter
Chromosorb
102PNA
Trap
Heat Exchanger
8 Water Trap
35°F
Engine Air
Laminar Flow Element
0-600cfm
Proportional Sampler
Control System
Dry Gas Meter
Servo Operated
Sampling Valve
Exhaust Sample
Laminar Flow Element
0-20 cfm
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13.
IV. RESULTS
A. Exhaust Sample Collection Developments
Table 2 summarizes the results of tests to analyze the PKA emissions
and to evaluate the collection and analysis schemes. All tests were run with
the DDAD 3-53 engine. The results have not been corrected for analytical losses.
Runs 1 and 2 show results of PNA collection using a direct filtration
procedure (Figure 4-A). These data appear to be remarkably reproducible.
Starting with Experiment 3, various PNA were either injected into
the exhaust gas or predeposited on the chromosorb to compare the recovery
obtained to that in the bench tests. Heated sample lines were used in
Experiments 3 through 5 (Figure 4-B) because work with the bench studies
indicated that a temperatue of 350°F (177°C) was needed to ensure that the
ERA would be in the vapor phase. Only the injected compounds (or those
predeposited on the chromosorb) were isolated.
The failure to recover any BaP in Run 3 was surprising and should
have been a warning that heating the sample might be a problem. The maximum
temperature at the point of taking the sample from the stack varied, depending
on engine operating conditions, from 130 to 850°F (54 to 454°C). Run 4 is a
strong indication that BaP is partially destroyed in the sampling system, that
is, less than 50$ of the injected BaP was recovered compared to the approximately
90$ in the bench tests. Run 5 indicates that destruction of BeP can occur
and that BaP predeposited on the chromosorb is partially lost. Because, in
bench studies, BaP on the chromsorb 102 trap was recovered in 90$ yield, the 20$
recovered in Run 5 probably means that most of the BaP reacted with constituents
in the exhaust gases. Similar loss of predeposited BaP on the chromosorb was
observed in Runs 6, 7, and 9.
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TABLE 2
ENGINE STUDIES OF PliA RECOVERY
Engine DDAD-3-53 - Fuel 2-5
Exp.
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Collection System (Figure No.)
Direct Filtration and Chromosorb-102 (4-A)
Direct Filtration and Chromosorb-102 (4-A)
Heated line (350°), Filtration, Chrom.-102 (4-B)
Heated line (350°), Filtration, Chrom.-102 (4-B)
Heated line (350°), Filtration, Chrom.-102 (4-B)
Condenser 4 Filter 4 Chromosorb-102 (4-C)
Condenser 4 Filter 4 Chrom.-102 (C16H34 on Filter )( 4-C )
Ammonia injection to determine whether NO is destroyed.
Air dil. (4/1) Temp. 75° 4 Filtration 4 Chrom.-102 (4-D)
Air dilution (4/1) (4-D)
Air dilution (4/1) Temp. -20° + filtration. (4-D)
Condenser 4 filter + Chromosorb-102 (4-C)
Heated line - Stack Sampling Procedure (4-E)
Cryogenic (-90°) bath + filtration 4 Chrom.-102, heated
line. Methanol injected. (4-F)
Cryogenic (-90°) bath 4 filtration + Chrom.-102
Methanol injected. (4-F)
Cryogenic (-90°) bath 4 filtration 4 Chrom.-102
(No methanol.) (4-F)
Precooler, cryogenic trap, filter (4-F)
Precooler, filtration + Chromosorb-102 (5)
Precooler, filtration + Chromosorb-102 (5)
Precooler, cryogenic trap 4 filter -
Ammoniated Methanol injected. (4-F)
Precooler, cryogenic trap 4 filter -
Ammoniated Methanol injected. (4-F)
Engine
Cycle
13-mode
13-mode
13-mode
13-mode
13-mode
13-mode
13-mode
1800 rpm
1/2 load
1800 rpm
1/2 load
1800 rpm
1/2 load
13-mode
1800 rpm
1/2 load
1800 rpm
1/2 load
13-mode
13-mode
13-mode
13-mode
13-mode
13-mode
l-3mode
Injected
crop
-
BaP
BaP
BeP
Bap(l)
BeP
Bap(l)
BeP
Bap(l)
BeP
Bepd)
C14BaP
BeP
Bap(l)
BepU)
BaP
BaA
BaP
BaA
BaP
BeP
-
-
C14BaP
-
C14BaP
C14BaP
C14BaP
Compound
JJg_
6
4.4
5.27
5
2.1
5
4.25
5
9.11
4.67
9.90
5.73
6.42
3.97
4.0
3.8
6.22
5.35
6.45
5.47
6.68
5.72
1.30
0.98
1.30
1.26
Recovery - jug/Test
BaP BeP BaA BghiP
0.56 0.66 O.S9 3.72
0.48 0.62 0.86 3.45
0 -
2.38 -
1.11 1.95
2.03 1.5
1.9 0.37
1.93 6.62
2.62 4.24
3.59(2) 3.57(2)
3.22*(2)
1.62(3) 3.83(3)
2.P6 - 1.6o(2)
0.0 (3) o.O (3)
0.64 - Trace
3.43 1.62 0 .96
0.16 0.69 0 0.14
0.39 0.23 Trace 0.20
0.45 000
0.04*
0.38 0.27 Trace 0.72
0.59 1.46 1.14 0.30
0.14*
0000
1.01 0.71 1.37 0.5S
0.22*
Exhaust
Volume
Sampled
7.50
7.67
7.39
7.67
6.34
6.40
6.88
-
6.80
6.51
5.24
6.97
5.21
6.80
7.31
8.30
7.99
6.85
7.76
7.76
7.90
Remarks
Injected over total cycle.
Injected during last 10 min
Injection during Mode 11.
Injection during Mode 10
and 11 (10 min.)
Injection during Mode 6
Condenser water not on.
No loss of HOX found.
Injection over whole test
(rest of runs).
Difficult to recover from
glass wool in trap.
Difficult to recover from
glass wool in trap.
Injection ahead of pre-
cooler temp .> 400 °F in Ng
stream.
Like #1 and 2.
Injection after precooler.
Lost.
Replaced Cu cooling coil
with stainless steel.
(1) Compound placed on Chromosorb-102 before starting run.
*Radioactive BaP.
(2) Recovered from filter and lines.
(3) Recovered from Chromosorb-102.
RSS-1974
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FIGURE 4
PNA COLLECTION SYSTEMS
15.
4A
4B
75°F-340°F
(2O°C-I7I°F)
40°F(4.4°C)
Heated Line
350°F (I77°C)
40°F (4.4°C)
LU
4C
75°F-340°F
(24°C-I7I°C)
40°F(4.4°C)
3508F(I77°C)
N2
3L/Min.
Run II
4D
-20°F(-29°C) RUN II
I40°F(60°C)RUN 9810
65°F(I8°C)
RUN 9 8 10
-40°F
(-40°C)
RUN II
AIR
NOTE: Qiass Wool in Necks of
Last Two Traps.
Dry Ice - Acetone
Ice a Salt Water
200 ml. Ethanol
I30°F-300°F
(540C-I49°C)
LEGEND
Syringe Injector
Participate
Filter
Chromosorb 102
Trap
Condenser
Liquid Trap
Pre-Cooler
60°F Water
Methanol
Where Applicable
Trap
NOTE: Steel or Glass
Wool in Both
Trap Traps.
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16.
Because BaP recovery was low with a heated sample line, it was
decided that cooling the exhaust gas sample might be beneficial. Runs 6,
1, and 12 use a heat exchanger ahead of the filter (Figure 4-C) to lower
the sample temperature. In Run 6, BeP loss was only 30$ but BaP loss was
60/o. In Run 7 the losses were 90$ and 60% respectively, possibly because
water was not used in the heat exchanger. In Run 12, (• •- 35$) of both BaP
and BaA was recovered. By separate analyses in Run 12, approximately equal
amounts of these compounds were found in the sampling lines, condenser and
condensate, and on the filter. There was none of either compound on the
Chromosorb-102 trap, suggesting that this trap is unnecessary for recovery
of the PNA hydrocarbons. However, it is known that phenols do collect on
this trap.
Since a water-cooled condenser did not significantly improve the
total recovery, an air dilution system was tried (Figure 4-D). In these
experiments (9, 10, and 11), instrument air, passed through a Chromosorb-102
trap to remove hydrocarbons, was introduced into the sampling system so that
a 4/1 ratio of air to exhaust gas flow was maintained. These air dilution
experiments were run at constant engine speed and load where it is easy to
maintain steady flow. It would be possible to do the same thing for the
13-mode cycle but quite impractical to use air dilution with the smoke cycle
and the proportional sampler.
In Run 9 an approximate 65$ recovery of injected BeP was obtained,
whereas in Run 10 the recovery of BaP was about 20$. Run 11, in which the
added air was about -40°F (-40C), resulted in a sample stream temperature
of -20F (-29°C). This run resulted in the best recovery of BaP, 50$ of the
amount injected. One problem encountered was the occasional freezing of the
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17.
exhaust stream as it mixed with the cold air. A solution to this problem
was not found.
Calculating the recovery of injected PKA from these experiments
is complicated by not knowing exactly how much was produced in the engine. .
Because we think the injected BaP greatly exceed the BaP from the engine,
we have ignored the engine produced BaP in estimating PNA recovery.
B. Application of Radiotracers
The Project Group had been urging Gulf Research & Development
Company to employ radioactive tracers to help understand what was happening
during sampling. This approach had not been pursued because the analytical
equipment was not available at Gulf Research & Development Company. In
March 1974, representatives of the Ethyl Corporation and Chevron Research then
volunteered to do the radioassays. Later, we arranged for New England Nuclear
Company to do this analysis on a routine basis. Through the courtesy of
Dr. Margaret Griffing of the Ethyl Corporation, the Contractor was supplied
with a quantity of radioactive benzo(a)pyrene (C14BaP). The C14:BaP permitted
us to distinguish between BaP injected and BaP produced by the engine. The
high purity of the C BaP was established by UV spectral analysis.
The use of C14BaP in Experiment 11 showed several things. Both
C14BaP (6.42 ;ug) and BeP (3.97 ug) were injected while non-radioactive
BaP (4.0/ig) and BeP (3.8 ug) were predeposited on the chromosorb trap. Upon
analysis, 3.57 jag of BeP (~ 74$) was recovered from the lines and filter while
3.83 jug Bep (~ 100$) was recovered from the Chromosorb-102 trap. This recovery
of BeP is considered excellent.
-------
18.
14
Table 3 gives an analysis of the C BaP distribution found in
Experiment 11. Of the injected C BaP, 50$ was recovered from the lines and
filters, 2.2$ in the BaP fraction from the chromosorb, and 21.5$ in the form
of degradation products from other parts of the system including the soot,
the alumina column and other TLC fractions. The finding of 2$ on the
Chromosorb-102 means that very little BaP gets beyond the filter. The
14
presence of only 3$ C BaP in the BeP fraction is an indication of the very
good separation of these compounds by the thin layer chromatographic procedure.
Furthermore, these two compounds can be readily distinguished by UV spectrescopy.
Table 3 also contains the results of UV analysis for total BaP. These
data (uncorrected for analytical losses) represent direct measurement of the
compound using a calibration curve developed with BaP standard samples. The
use of a radioactive tracer injected into the sample stream should permit
measurement of the amount of BaP in the exhaust by applying a factor for
recovery. This is not true when the radioactive spike is added to collected
samples of exhaust emissions which contain a complex mixture of soot, unburned
fuel, and partial oxidation products.
Even though the cold air dilution technique gave an adequate
recovery of PKA, the difficulties due to water freezing in the line and of
collecting a proportional sample, led us to look for another technique. We
next tried a procedure recommended for use in analyzing stationary stack gas
samples, Figure 4-E. This method utilizes a heated line followed by glass
traps containing ethanol cooled in dry ice. The trapping went well but the
method was unsatisfactory; only 10$ of the injected BaP was recovered and
only a trace of the BaA was found.
-------
19.
TABLE 3
,14.
ANALYSIS OF RADIOTRACER AMD UV RESULTS
EXPERIMENT NO. 11
DDAD 3-53 Engine - 1800 rpm, 1/2 Load
6.42 ug C BaP Injected - 4.0 ug BaP Pre-Loaded on Chromosorb Trap
Lines & Filter
Chromosorb Trap
Carbon14 Balance
C14BaP
3.22 50.0
0.14 2.2
C14X(3)
1.38 21.5
Total BaP by UV
Aig %
3.58(1) N/A
1.62 37.C
Total
3.36 52.2
1.38 21.5
5.20
(1) Includes C BaP plus engine produced BaP.
14
(2) Corrected for C BaP found on trap.
14
(3) Other includes C activity measured in the following:
BeP fraction (0.097 jag), other TLC fractions (0.637 ,ug),
soot (0.339/ug) and Alumina (0.305 ,ug). Most, if not all,
of this activity is associated with degradation products
of BaP. Weights reported are calculated as BaP based on
radioassay.
-------
20.
Five other cryogenic trapping experiments were conducted using
more efficient traps; a typical system is shown in Figure 4-F. In all these
experiments, glass wool or steel wool was used in either the first or second
trap to separate the condensed water. In Run 14, about 43$ of BaP was
recovered though only about 17$ of BeP was recovered. Runs 15 and 16 were
made without injecting PNA and represent direct comparisons with Runs 1
and 2. In Run 15 (as well as Run 14) methanol was injected to prevent ice
formation. In Run 16, no methanol was used and water vapor was collected
as snow on glass wool. In Run 21, methanol containing ammonia was injected
to keep the condensate basic. In Runs 15 and 16, recoveries of PNA were
lower than in Runs 1 and 2. Run 21 resulted in higher recoveries except
for BghiP.
In all of the cryogenic experiments, difficulties were encountered
because of the very large volumes of liquids that had to be extracted. Glass
wool or steel wool had to be used to collect the entrained droplets of
condensate. It was later found that recovery of PNA from either of these
packing agents is difficult.
Two runs (18 and 19), were also similar to 1 and 2, except that
a precooler in the sample line was used (Figure 5). This precooler is not
intended to condense water vapor but to cool the exhaust to a temperature at
which reactions are less likely to occur. Again, recoveries of PNA (except
for BghiP) comparable to Runs 1 and 2 were obtained.
Table 4 lists the recovery of BaP and BeP produced by the,engine
on a constant exhaust volume basis. Experiments included in this table were
conducted either without BaP injection or with the use of radioactive C-^BaP
to distinguish from the engine produced material. The amount of engine produced
-------
21.
TABLE 4
ENGINE PRODUCED BaP
No.
1
2
15
16
17
18
19
21
DDAD 3-53 Engine - Fuel 2-5
Test Conditions - 13-Mode Federal Cycle
Collection System (Figure No.)
Direct filtration and Chromosorb-102 (4-A)
Direct filtration and Chromosorb-102 (4-A)
Cryogenic Bath, methanol injected,
Direct filtration (4-F)
Cryogenic Bath, direct filtration (4-F)
Precooler, cryogenic trap, filter (4-F)
Precooler, direct filtration (5)
Precooler, direct filtration (5)
Precooler, cryogenic trap + filter + amraoniated
BaP
ng/M3*
75
63
20
47
51
56
58
100
BeP
ng/M3*
88
81
94
28
0
39
188
90
methanol injected. (4-F)
Average 58 76
Std. Dev. 26 57
*Namograms per cubic meter of exhaust gas.
-------
22.
BaP is relatively constant. We suspect, based on these experiments, that
engine produced PNA may have behaved differently than injected PNA. This
hypothesis is fortified by measurements of injected PNA, Table 5. Data
for this table were estimated either from C14BaP injected or by subtracting
the average engine produced PNA as estimated in Table 4. Only full 13-mode
cycle runs were considered. Injected BaP recovery depended greatly on the
sampling procedure and varied from 0 to 40$. One explanation for this
difference is that the PNA from the engine were stabilized on the soot particles
whereas the injected PNA reacted with constituents in the exhaust gases.
Presumably, some of the injected PNA was destroyed.
If this is the case, then a collection system involving the
precooler, filter, and chromosorb trap should be adequate to collect PNA
from diesel exhaust.
With the Project Group's concurrence, the collection system shown
in Figure 5 was adopted. It consists of a precooler to maintain sample
temperature below 350°F (177°C), a 12" (30 cm) filter holder (Gelman Type A
filters), the Chromosorb-102 trap and a heat exchanger with condensate trap.
The 12" filter reduces the need to change filter papers during a run.
C. Analysis of Diesel Fuels
A principal aspect of the CAPE-24 Project was to determine
typical PNA levels in diesel fuels. To this end, five ASTM 1-D and sixteen
ASTM 2-D diesel fuels were obtained from around the country for analysis.
-------
23.
TABLE 5
RECOVERY OF INJECTED MA
Exp. Percent Recovery
No. System (Figure Mo.) BaF BeP BaA
3 Direct Filtration (4-B) 0
4 Short exposure time of added PNA 41
Direct Filtration (4-B)
5 Short exposure time of added PNA 23
Direct Filtration (4-B)
6 40° Condenser (4-C) 35
7 65° Air Cooled Condenser (4-C) <7
12 40° Condenser (4-C) 27 16
17 Precooler, Cryogenic Trap (4-F) 3*
19 Precooler, Direct Filtration (5) 14*
21 Precooler, -90° Cryogenic Trap (4-F) 17*
^Radioactive Recovery.
-------
FIGURE 5
FINALIZED PNA COLLECTION SYSTEM
I30°F-300°F
'(54°C-I49°C
I2in. (30cm)
Filter
Gel man Type "A"
/ Precooler
. * I
, r
i i i
i
i
Water
X
111
UJ
Proportional
Sampler
Chromsorb 102
Trap
Condenser-40°F (4.4°C)
Water Trap
-------
25.
Table 6 gives the inspection data for these fuels as well as
the cities where they were obtained. All fuels meet specifications set
forth by engine makers.
Table 7 lists the analytical results for ENA. The first four
columns are the principal ERA hydrocarbons that we have concentrated upon.
Concentration of individual ENA ranges over nearly three orders of
magnitude among the different fuels. There is no correlation of ENA content
with either aromatic content or 90$ distillation temperature.
A comparison of these results with gasoline is of interest.
Gross^ ' reports that gasolines vary in BaF content from "near zero" to
an average 500 ppb to a field maximum 3000 ppb. The limited data in
Table 6 suggests that ASTM 2-D fuels average less BaF, and probably other
ENA, than gasoline even though the boiling range can encompass many ENA.
This fuel difference may result from the fact that diesel fuels are
essentially all non-cracked products obtained by distillation while
gasolines are principally made from products that have been catalytically
processed. Such processes may lead to either lighter components or to
reformed components, both containing aromatics.
Fuel 2-5 was used in all of the preliminary engine studies.
Since it is in the lowest range of ENA content, it is not desirable as
the baseline fuel for the determination of representative ENA emissions.
Because of the cost in both time and money of selecting a particular fuel
with a given ENA content, it was decided to make a blend of eight fuels
for the baseline studies. This fuel, 2-16, was prepared by blending eight
-------
TABLE 6
SURVEY FUEL INSPECTION DATA
Code
No.
1-1
1-2
1-3
1-4
1-5
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
Source
Wo. 1 Fuels - Kerosene
Philadelphia, PA
Anacortes, WA
Wood River, IL
Nederland TX
Baton Rouge, LA
No. 2 Diesel Fuels
Toledo, OH
Santa Fe Springs, CA
Port Arthur, TX
Cincinnati, OH
Philadelphia, PA
Jacksonville, FL
Denver, CO
Sullivan, MO
Waterville, ME
S. Gate, CA
Oklahoma City, OK
Portland, OR
Columbus, OH
Omaha , NE
Wheeling, WV
Composite Test Fuel
Columbus, IN
API
Gravity
42.0
43.8
44.0
41.6
41.3
34.2
36.2
34.5
35.4
33.3
34.2
34.6
33.6
33.6
34.0
36.5
36.6
35.7
35.6
35.0
36.9
35.1
Density
.8156
.8072
.8063
.8174
.8189
0.8540
0.8438
0.8524
0.8478
0.8588
0.8540
0.8520
0.8572
0.8572
0.3550
0.8422
0.8418
0.8462
0.8468
0.8499
0.8425
0.8493
Cetane
Index
47
49
51
51
50
48
52.5
46
45
42.5
47
44.5
42
41
49
50
49
46
47
46
50
48.5
FIA
Aroma tics
18.0
19.0
18.5
15.5
20.5
31.0 '
28.5
28.5
30.5
39.0
26.5
33.5
37.5
22.0
31.0
27.5
28.5
31.5
31.0
29.5
26.0
35.1
Olefins
.5
.5
1.0
.5
.5
.5
.5
.5
.5
.5
0.5
2.0
.5
.5
.5
.5
.5
.5
2.0
.5
0.5
4.0
Distillation
Sulfur
0.015
0.007
0.032
0.044
0.039
0.21
0.52
0.20
0.18
0.08
0.13
0.32
0.13
0.17
0.28
0.32
0.21
0.20
0.33
0.14
0.17
0.21
10
380
360
373
402
381
434
444
422
416
424
418
400
430
402
443
414
408
408
414
431
417
412
50
420
412
418
447
440
516
518
502
486
494
518
490
494
480
530
498
488
486
492
496
498
508
90
464
476
477
492
498
599
593
591
567
582
610
586
564
576
606
600
578
564
572
560
589
596
to
cn
-------
TABLE 7
Compound :
Code No.
1-1
1-2
1-3
1-4
1-5
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
MDL
* Equal
BaP
3
1
<1
<1
1
69
40
10
50
9
274
86
256
9
2
422
12
-------
28.
ASTM 2-D fuels available in the Pittsburgh area. Each supplier assured us
that they had prepared the fuel and that it was not an exchange product.
The suppliers were Amoco, Arco, Boron, Exxon, Mobil, Pennzoil, Sun, and
Texaco. This blended fuel, which has typical inspection, has about six times
the amount of the four PlA's of interest compared to Fuel 2-5 used in the
preliminary experiments of this report. The PWA content is in the mid-range
of the fuels surveyed.
D. Engine Repeatability Studies
Four 13-mode tests were conducted to measure repeatability of the
total system. Engine operation was identical in each test. The baseline
fuel (2-16) and the sampling apparatus shown in Figure 5 were used. Because
injected BaP appeared to react differently than engine produced BaP that
14
remained in the exhaust, the exhaust gas was not spiked with a C tracer.
Instead, after the exhaust sample has been collected, the solutions from
14
the soot extraction were spiked with C BaP to measure the BaP recovery
during the analytical procedure.
Table 8 gives the results of these tests. Note first that the
14 j „/
recovery of the C BaP spike is only about 2870 compared with the B5% recovery
when analyzing fuels (Table A-2). The 28% recovery of BaP indicates BaP and
probably other PWA react with other exhaust products even in the liquid phase.
The recovery of the three other principal PNA's are only corrected for analytical
loss as described in Appendix A (Table A-2). No correction for recovery was
applied to the remaining compounds because no recovery data have been obtained
for them.
-------
29.
TABLE 8
13-MODE TEST REPEATABILITY
DDAD 3-53 Engine - Fuel 2-16
Experiment No. 22
Percent Recovery
of Radioactive BaP* 28.8
Compound - ;ug per Test
BaP, corrected 1.59
BeP 0.79
BaA -.01
BghiP 0 . 20
Chrysene 0 . 80
Pyrene 32 . 3
Phenanthrene 491
Fluoranthene 23.9
Phenanthrene Der. 445
Phenols 1280
23 24 26 Avg. Std.Dev.
(28**) 20.0 28.2 26 4.2
0.84 1.93 0.63 1.25 0.64
-.01 ^.01 0.18 0.24 0.37
•^.01 •v.Ol '.01
0.27 1.00 0.06 0.38 0.42
T.03 0.13 0.87 0.45 0.45
17.3 15.0 14.5 19.8 4.4
340 276 343 362.5 90
19.4 10.5 7.0 15.2 9.8
300 675 464 471 154
840 752 504 849 306
^Radioactive spike added to solutions of sample before analytical recovery is started.
**The material recovered in this sample where BaP was expected did not contain BaP.
From the UV spectra of another fraction, BaP was identified. A 28% recovery factor
was assumed.
-------
30.
The amount of each individual compound in the exhaust sample
shows a large variation. We have no explanation for this variation. The
collected soot using the baseline fuel was far more tarry than the soot with
Fuel 2-5. We also experienced greater difficulty in obtaining pure fractions
during the separation because other UV-absorbing substances eluted with the
PNA of interest. This may be an explanation of why the BaA yield is so
much lower than BaP. In gasoline exhaust studies BaA always was found in
larger amounts than BaP. Further work to improve the separation is planned.
E. Additional Engine Studies
At the request of the Project Group, a double length test (i.e., two
13-mode cycles) was conducted. The results appear in Table 9. This test
should give an idea about sampling losses during sample collection.
Recovery of the C BaP spike was 28%, comparable to that obtained
in the replicate tests. Because of the large amount of tar in this test,
the filter paper containing the particulates was re-extracted and the solution
separately spiked before processing. Not a great deal of additional PEA
was recovered but the recovery for the C BaP spike was 87.5/0 which compares
well with the 85% recovery for fuels. This result indicates that the species
which react with PNA were extracted with the PNA in the first extraction.
It was also observed in the double length test that BaP, BghiP,
pyrene, chrysene, and fluoranthene were recovered at about the same con-
centration as in the single length tests. This may indicate that these
compounds are partially lost during sampling. Phenanthrene, the phenanthrene
derivative and total phenols are recovered at about double the concentration.
-------
31.
TABLE 9
PNA RECOVERY
Percent Recovery
of Radioactive BaP
Compound
BaP, Corrected
BeP
BaA
BghiP
Chrysene
Pyrene
Phenanthrene
Fluoranthene
Phenanthrene Der.
Phenols
IN DOUBLE LENGTH 13-M3DE CYCLE TEST
Average of 4
Single Length
Tests
26
Ug/Test
1.25
0.24
£.03
0.38
0.45
19.8
362
15.2
431
849
Double
Std. Dev. Length Test
4.2 28.1(87.5)*
ug/Test
0.64 1.21
0.37 <.01
<.01
0.42 0.78
0.45 1.00
4.4 25.9
90. 757
9.8 18.2
154 1089
306 1858
*Recovery of
aP spike from second extraction of carbon deposits.
-------
32.
This suggests that the more stable compounds are recovered in better yield.
However, because the test variability is so high, this experiment cannot be
considered conclusive.
A single run has been made using the smoke cycle (see Appendix C).
No difficulties were encountered in the use of the proportional sampler or
the DATA-TRAK controller. The filter paper was found to be quite wet with
condensed water, probably the result of the extensive idle in this cycle
(even though the idle period was reduced from 5 minutes to only 1 minute).
A very large amount of soot was collected in this test and the PNA found
was low. Table 10 gives the PKA found for this test.
TABLE 10
PMA EMISSIONS FROM THE SMOKE CYCLE
Compound ug/kg Fuel
BaP, Corrected 1.1
Pyrene 39.
Fluoranthene 17.
Phenanthrene 233.
Phenanthrene Derivative 320.
Phenol 2080.
-------
33.
14
No other PNA were found. In addition, recovery of the C BaP spike amounted
to only 13.7$. Whether the low PNA yield indicates destruction after sampling
or destruction due to the high exhaust temperature, is not yet known. The
yield, particularly for the lower molecular weight species, are much lower
in the smoke cycle test than in the 13-mode tests. These tests will be
repeated.
F. Comparison of Exhaust PNA and Fuel FNA
Table 11 compares the recovery of PNA on the basis of ug per cubic
meter of exhaust gases, ug per gallon, and ug per kg of fuel used. These
data are average values for the four 13-mode cycles run with the baseline
fuel. Also included in the table is the concentration of these PNA in the
fuel. Anthracene was present in the fuel but not in the exhaust gas.
Conversely, phenanthrene was in the exhaust gas but not in the fuel.
In spite of the fact that the first 21 runs were made with a variety
of test procedures, a number of them can be used to calculate an average yield
of PNA for Fuel 2-5. They include Runs 1, 2, 15, 16, 17, 18, 19, and 21 for
which analytical data were available. Table 12 compares the PNA recovery in
ug/test for both Fuel 2-5 and 2-16. It is not possible to give a corrected
recovery for BaP with Fuel 2-5 since radioactive BaP, if incorporated, was
injected into the exhaust sample stream. The PNA in the exhaust gas from
both fuels is similar but with differences. The variability based on
standard deviations is comparable. There is no evidence that variation in
sampling procedure used with Fuel 2-5 has increased the variability of
recovery. The low yield of BaA with Fuel 2-16 may be an artifact due to the
separation procedure. With this fuel, a considerable amount of background
material present with the expected BaA cut.
-------
34.
TABLE 11
AVERAGE
Compound
BaP
BeP
BaA
BghiP
Chrysene
Pyrene
Anthracene
Fluoranthene
Phenanthrene
Phenanthrene Der.
Phenols
PNA EMISSIONS FROM FOUR 13-MODE
DDAD 3-53 Engine
Exhaust Gas
0.158
0.031
-
0.048
0.035
2.501
-
1.88
46.1
59.8
107.2
- Fuel 2-16
Aig/Gal.
Fuel Burned
.*
4
-
7
5
349
-
253
6410
8280
14900
CYCLES
Fuel Burned
6.9
1.3
-
2.2
1.6
110
-
79
2013
2600
4680
/ug/Kg.
In Fuel
41
75
108
26
72
144
31400
869
-
-
35000
-------
35.
TABLE 12
COMPARISON OF PNA FOUND WITH FUELS 2-5 AND 2-16
Fuel-2-5 Fuel 2-16
BaP
BeP
BaA
BghiP
Chry
Pyr
Phen
Fluo
Phen Der.
Phenols
Average
jog/Test
0.48
0.58
0.50
1.14
1.48
21.9
448.
ED
ND
1014.
Std.
Dev.
0.24
0.44
0.57
1.5
0.77
8.2
256.
ND
ND
266.
Average
ug/Test
1.25*
0.24
< 0.01
0.38
0.45
19.8
362.
15.2
431.
849.
Std.
Dev.
0.64
-
-
0.42
0.45
4.4
90.
9.8
154.
306.
14
^Corrected for analytical loss using C spike.
-------
36.
The uriburned fuel per test is calculated to be 0.102 kg, from
Table B-l. From the measured fuel consumption (16.51 kg), the fraction
unburned fuel in the exhaust is 0.62$. This unburned fuel contains, in
addition to the original fuel, a variety of thermal degradation products.
If synthesized ERA were not present in these degradation products, the
maximum yield of ENA would be 0.62$ of the PNA in the fuel consumed,
assuming all fuel components burn equal]Y .coll.
Table 13 compares the PNA found in the exhaust in ug/kg of fuel
burned and the percent PM of the original fuel for Fuels 2-5 and 2-16.
Because the data on BaP for Fuel 2-16 has been corrected to account for
losses, it is probable that the yield of this compound is essentially the
same for both fuels. In nearly every case, except anthracene, the percent
of compound present is much greater than 0.62% of the material in the
original fuel. This in turn supports the theory that ENA are formed as
byproducts of incomplete combustion.
G. Comparison of Gasoline and Diesel ENA emissions
While it is of interest to compare ENA emissions from gasoline
and diesel engines it must be remembered that the engine tests are conducted
using completely different procedures. Data reported in Table 14 for the
gasoline engine were obtained while the vehicle was operated repetitively
in the original 7-mode Federal cycled 'Data for the diesel engine were
obtained from the 13-mode Federal diesel emission procedure. Further,
the sampling and analytical procedures used in the two studies are totally
different. Ignoring these differences, Table 14 suggests that the diesel
engine produces less ENA than the uncontrolled gasoline engine jn terms of
eaiissions per gallon of fuel burned.
-------
37.
TABLE 13
BaP
BeP
BaA
BghiP
Pyr
Chry
Anth
Flou
Phen
Phen Der.
Phenols
COMPARISON OF
Fuel
ug/kg
Fuel Burned
2.7
3.3
2.7
6.5
121
8.2
0
0
2409
-
5600
EXHAUST PNA TO PNA IN FUEL
2-5
of Fuel PNA
in Exhaust
30
32
18
72
27
1
0
0
CO
-
15
Fuel
Jig/kg
Fuel Burned
7
1
-
2
110
3
0
85
2015
2396
4723
2-16
% of Fuel PNA
in Exhaust
17
2
0
8
76
4
0
10
00
co
13
-------
38.
TABLE 14
PNA EMISSIONS FROM DIESEL AND GASOLINE ENGINES
ug/gal. of Fuel Burned
Uncontrolled Controlled
Car Car DDAD-5-55 Engine
ie.b 132
13 22
48 4
32
56 1
87 7
411 349
383 269
Fuel BaP (ug/gal)
BaP
BeP
BaA
BghiP
Chry
Pyr
Fluo
H. Analysis of
45
77
244
119
358
231
2228
1869
Gaseous Emissions
Part of the requirement for this project is to determine gaseous
emissions during the 13-mode cycle, and smoke emissions during the smoke
cycle. Results are in Table 15. Analytical data for each mode is given
in Appendix C. These data were obtained from the four reproducibility
tests plus the one smoke cycle using the baseline fuel.
Both gaseous and smoke emissions were below 1974 standards for
heavy duty diesel engines and are typical for this engine model.
-------
39.
TABLE 15
GASEOUS ENGINE EMISSIONS
Engine DDAD-5-55 - - Fuel 2-16
13-Mode Cycle
g/BHF-Hr.
CO 8.8
HC + WO 10.9
x
HC 1.5
NO 9.4
x
NO 7.5
Smoke Cycle
Mode % Opacity
Acceleration 18
Lugging 14
Peak 35
-------
40.
V. CONCLUSIONS
1. An adequate sampling system has been developed for PNA
collection. It consists of a gas precooler, particulate
filter and a Chromosorb-102 trap.
2. Recovery of PNA from diesel exhaust may be reduced by reactions
of PNA with other constituents in the exhaust. Injected ENA
shows greater variability in recovery with different sampling
systems than does the remaining engine emitted PNA.
3. Twenty diesel fuels ranged widely in PNA content, from 1 ppb
to 422 ppb for BaP and to 466 for BaA. These concentrations
are low relative to gasolines which have been found to contain
up to 3100 ppb of BaP.
4. There appears to be little effect due to fuels in yield of PNA
from the DDAD-3-53 engine.
-------
41.
VI. REFERENCES
1. S. K. Ray and R. Long, "Polycyclic Aromatic Hydrocarbon from Diffusion
Flames and Diesel Engine Combustion," Combustion and Flame 8_ 139-151 (1964)
2. C. Bailey, A. Javes, and J. Lock, "Investigation Into the Composition of
Diesel Engine Exhausts," Fifth World Petroleum Congress, Section VI,
Paper 13, page 209 (1959) New York, N.Y.
3. R. Hangebrauck, D. von Lehmden, and J. Meeker, "Source of Polynuclear
Hydrocarbons in the Atmosphere," U.S. Public Health Service Publication
Wo. 999-AP-33, National Center for Air Pollution Control (1967).
4. J. Colucci and C. Begeman, "The Automotive Contribution to Air Borne
Polynuclear Aromatic Hydrocarbons in Detroit," Journal of Air Pollution
Control Association 15, 113 (1965).
5. C. Begeman and J. Colucci, "Benzo(a)pyrene in Gasoline Partially Persists
in Automobile Exhaust," (letter) Science 163, 271, (1968).
6. G. Gross, "Fourth Annual Report on Gasoline Composition and Vehicle
Exhaust Gas Polynuclear Aromatic Content," Pages 1, 17, 18 (October 1973)
Coordinating Research Council.
7. "Analysis of the Odorous Compounds in Diesel Engine Exhaust." Final
Report - June 1972 to CRC.
8. Title 40, Part 85 "Control of Air Pollution from New Motor Vehicles and
New Motor Vehicle Engines," Federal Register, 37_ No. 221, 24250-24320,
November 15, 1972.
-------
42.
APPENDIX A
ANALYTICAL PROCEDURES
I. PKA HYDROCARBONS IN DIESEL FUEL
The polynuclear aromatics (PKA) were concentrated by alumina gel
column chromotography, separated by thin layer chromotography, and identified
by ultraviolet spectrophotometry.
All solvents, reagents, and equipment were free of PNA and PKA
separations were performed in subdued light to reduce degradation of PNA.
A. FKA Concentration
The analytical scheme used to separate the PKA hydrocarbons from
the diesel fuel is given in Figure A-l. The concentration step is done
with a 35 x 1.9 cm glass column packed with 60 g of 2.5$ water deactivated
Woelm Alumina. In practice, 20 grams of fuel is placed on the column and
eluted with a group of solvents. The first 400 ml of isooctane (10) and
the 300 ml of 10 containing 20% benzene removes most of the saturates and
light aromatics. Cut 3 was eluted with 800 ml of a 50/50 mixture of 10 and
benzene followed by 100 ml of benzene. Cut 4, not used in this work, is
obtained by an additional 700 ml of benzene. The four PWA analyzed for
in this investigation, benz(a)anthracene (BaA), benzo(e)pyrene (BeP),
benzo(a)pyrene (BaP), and benzo(g,h,i)perylene (BghiP) are recovered quanti-
tatively as shown in Table A-l.
The water content of the alumina gel is important. The water
content of the gel was determined by the weight loss of 10 g of gel after
-------
FIGURE A-l
DIESEL FUEL PNA SEPARATION PROCEDURE
Fuel Sample (20 g)
1
Alumina, Woelm Neutral
2.5$ Water Deactivated
1
4- v
Cut #1 Cut #2
^ '
Cut #3
800 ml - I0/Benzene (50/50)
400 ml - 10 300 ml - I0/Benzene (80/20) + 100 ml Benzene
J
Cellulose TLC, 1 mm
1
I
1 '
Cut #4
700 ml Benzene
\ >
Cellulose TLC, 1 mm
I
Cut A Cut B Acetylated Cellulose, 1 mm
I
Cellulose TLC, 0.5 mm
1
Acetylated Cellulose. 1 mm
i
I
t v
V TTV
I
UV
-------
44.
TABLE A-l
Cut
1
2
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3-12
3-13
3-14
3-15
3-16
4-1
4-2
Ml.
400
300
50
50
50
50
50
50
50
50
50
40
50
50
50
50
50
50
50
50
PNA RECOVERY - ALUMINA, NEUTRAL, 2.5% WATER DEACTIVATED
10 jug Each PNA in Isooctane
Pyrene BaA BeP BaP
Eluant jug % jug % Aig % &g %
1-0
I-0/Benz.( 80/20)
I-0/Benz.( 50/50) 4.0 40
" 4.1 41
1.9 19
"
" 1.2 12
11 2.6 26
" 2.4 24 2.2 22
" 2.0 20 3.7 37
" 1.0 10 2.8 28
" 1.3 13 1.4 14
» 2.1 21
" 1.9 19
" 2.0 20
» 2.6 26
ti
ii
Benzene
Benzene
BghiP
TOTAL 10.0 100 9.2 92 10.0 100 10.0 100 10.0 1
-------
45.
Appendix A
heating for 10 minutes at a red heat over a Bunsen burner. Then the desired
amount of unheated gel is placed in a bottle and the necessary amount of water
added to give the desired water content. After equilibration overnight, the
content is verified by repeating the above procedure. The water content should
be +0.1 wt. % of the desired level.
B. Thin Layer Separation
The cellulose and acetylated cellulose must be prewashed to remove
interfering ultraviolet absorbing material. A slurry of the absorbent in
methanol is agitated in a Waring blender for 5 minutes, transferred to a
Buchner funnel and rinsed twice with more methanol before air drying.
The cellulose thin-layer plates are prepared by adding 26 g of
cellulose to 170 ml water and mixing for 3 minutes in a Waring blender.
The solution is transferred immediately to the applicator for the preparation
of about 4 plates 20 x 20 cm and 1 mm thickness. After air drying, the
plates are developed with 10 to remove additional interfering components,
then stored in a dessicator.
The acetylated cellulose plates are prepared by mixing 40 g of
acetylated cellulose and 150 ml of 95$ ethanol in a Waring blender for
3 minutes. This provides sufficient material for about 8 plates 20 x 10 cm
x 1 mm. These plates are air dried and stored in a dessicator.
C. Cellulose "Prep" Plate
The effluent of interest, for instance cut 3, is concentrated
to approximately 0.3 ml in benzene and streaked in a very narrow band with
a 50 ,ul syringe about 2 cm from the bottom and 2 cm from the sides of the
-------
46.
Appendix A
plate. Also, a spot of BaP is placed on the extreme side of the plate as
a reference compound. The plate is then immersed, from the end opposite
the sample, in a solution of 20/o N,W-dimethylformamide (DMF) in ether, which
migrates to within 0.5 cm of the applied sample. The plate is removed and
air dried for approximately 15 seconds, then developed in the reverse direction
with 10 as the mobile phase.
Two cuts, A and B are removed from the cellulose "prep" plate for
further separation. This "prep" step is usually necessary "because of the
relatively high concentration of lower molecular weight PNA making the
detection of individual bands difficult. The plate is observed under ultra-
violet light and the upper limit of Cut A marked with a pencil line between
the R for BaP, as observed with the BaP standard, and the next higher Rf
band, which is pyrene. The lower limit of Cut A extends down to, but not
including, the starting line. Cut B is the material remaining on the plate
excluding the uppermost, usually yellow, band which is discarded. These cuts
are scraped from the plate into separate Pyrex brand extraction thimbles with
a coarse porosity disc and Soxhlet extracted for 2 hours with benzene.
D. Cellulose Separation
Cut A is concentrated to about 0.3 ml benzene, whereas Cut B, due
to higher solute concentrations, is diluted to 25 ml with benzene and then
an aliquot, usually 1 ml, concentrated to 0.3 ml. These samples are applied
to cellulose plates 0.5 mm thick along with a BaP standard at the side and
developed as done previously for the cellulose "prep" plates. The plates are
then examined briefly under ultraviolet light and the fluorescent bands
observed, outlined with a pencil and the Rf compared to the BaP standard.
-------
47.
Appendix A
The outlined bands are transferred into separate 50 ml beakers and extracted
three times with about 10 ml of hot methanol. The methanol is filtered
through a pressure sintered glass filter into a 50 ml Erlenmeyer flask and
concentrated to approximately 0.3 ml of benzene by adding 30 ml of benzene
in 10 ml increments.
This concentrate is then applied to 20 x 10 cm cellulose acetate
plates 1 mm thick and developed by a mobile phase consisting of ethanol,
toluene and water (13:4:4, v/v/v). When the solvent migrates to within 1 cm
of the top, the plate is removed and the fluorescent bands outlined and
transferred directly into the pressure filter and washed with hot methanol
in three 10 ml increments. The filter effluent is collected in 50 ml
Erlenmeyer flasks and, after adding 1 ml n-hexadecane, evaporated to 1 ml.
Three 10 ml portions of 10 are added to the flasks with evaporation after each
addition to remove all other solvents. The 1 ml n-hexadecane is transferred
to a 1 cm ultraviolet cell and scanned for absorption in the 220-400 nm
region. Identification and quantification is done by reference to previously
prepared absorption spectra.
E. Recovery
Two experiments were done to study the recovery and repeatability
of the procedure for the fuel analysis system. In each case, 1 ug each of BaA,
BaP, BeP, and BghiP were added to 20 g of a No. 2 fuel oil. This fuel blend
was then put through the complete analytical separation. The result, given in
Table A-2, indicates the average recovery and repeatability of the procedure
after correction for the 10 ug/kg max., PNA in the original oil. The average
recovery data have been used to correct the fuel survey results.
-------
48.
TABLE A-2
PNA RECOVERY STUDY, NO. 2 FUEL OIL
PNA Added Amount % Recovery Avg. % Recovery
Benz ( a ) anthracene
Benzo(a)pyrene
Benzo(e)pyrene
Benzo(g,h,i)perylene
1 Jig
1 Jig
i ps
1 ug
72, 74
81, 88
100, 100
98, 94
73
85
100
96
-------
49.
Appendix A
II. DIESEL EXHAUST GAS ANALYSIS
The exhaust gas sample preparation steps are shown in Figure A-2.
Each of the elements of the exhaust gas sampling system are considered
separately because of the various procedures used.
A. Chromosorb-102
The Chromosorb-102 is reverse flushed with 100 ml of methanol
followed by 100 ml of benzene which removes phenolic and hydrocarbon materials.
Quite often this trap contains some moisture and the pre-wash with methanol
allows a more effective subsequent wash with benzene.
B. Lines
All of the connecting lines in the exhaust sampling system are
disassembled and cleaned thoroughly with a brush and benzene.
C. Filter Paper
The filter housing is cleaned with a brush and benzene and the
solvent added to that obtained when the lines were washed. The filter paper
is cut into about 1 cm squares and placed in an extraction thimble. Then
the solutions from the Chromosorb-102 trap, lines and filter housing are
filtered through the extraction thimble into a 1-liter volumetric flask and
14
approximately 0.1/ug C BaP added. Thus, any soot particles in the rinse
solutions, are retained in the thimble along with the filter paper. The
filter paper and soot are extracted for 16 hours with a benzene-methanol
mixture (60-40, v/v).
The Soxhlet extract is added to the 1-liter flask and the contents
adjusted to the mark with isooctane. Then, 25 ml is withdrawn from the flask,
diluted with 100 ml isooctane and caustic extracted three times with 0.5 W
-------
50.
FIGURE A-2
EXHAUST GAS SAMPLE PREPARATION
CHROMOSORB-1-2 LINES FILTER PAPER WATER
Methanol Benzene Soxhlet Extraction Phen
and Benzene-Methanol
Benzene For 16 Hours
V >f
>
Exhaust Ga
Concentrate in
Combine Extracts
in 1 Liter Flask
1
Remove 2 5 -ml
1
Extract
With 0.5N NaOH
1 1
Hydrocarbon Caustic
Phase Phase
4
— ~ Phenol a ^ ~~
s Hydrocarbon ^
5 ml Isooctane Total Phenols
TRAP
Is
PNA Separation
-------
51.
Appendix A
sodium hydroxide. The caustic phase is added to the contents of the water
trap and analyzed for total phenol. The extracted hydrocarbon phase is
recomibined with the contents of the 1-liter flask and evaporated on a
steam bath under a stream of nitrogen to approximately 5 ml of isooctane.
D. ENA Concentration
The ENA concentration scheme for exhaust gas is shown in Figure A-3
which removes interfering ultraviolet absorbing material and unwanted saturate
and aromatic components.
The hydrocarbon concentrate in about 5 ml isooctane, obtained
by the exhaust gas sample preparation, Figure A-2, is placed on a 20 x 1.7 cm
glass column containing 15 g of alumina, Woelm neutral, deactivated with
10$ water, and eluted with 150 ml isooctane. The isooctane eluate is allowed
to flow directly onto a second column of the same dimensions, but containing
15 g of alumina, Woelm neutral, deactivated with 2.5$ water. After the top
column is dry and the bottom column still has a layer of isooctane over the
alumina, the bottom column is separated and eluted with 150 ml of benzene.
This fraction,which contains the ENA of interest, is concentrated to about
0.3 ml in benzene and separated by cellulose and acetylated cellulose TLC
as shown in Figure A-l and described in the fuel oil analysis section.
This two-column separation was verified by separating a known
mixture of ENA in isooctane. Recoveries ranged between 90 and 100$ for
benzo(a)pyrene, benzo(g,h,i)perylene and coronene. All ENA of interest for
this investigation lie between the elution volumes of these compounds.
-------
52.
FIGURE A-3
EXHAUST GAS SAMPLE PNA SEPARATION
EXHAUST. GAS HYDROCARBON CONCENTRATE
T
Alumina, Woe1m Neutral
10/o Water Deactivated
ISOOCTANE FRACTION, 150-ml
i
Alumina, Woelm Neutral
2.5$ Water Deactivated
ISOOCTANE, 150-ml
V
DISCARD
BENZENE, 150-ml
PNA CONCENTRATE
-------
53.
Appendix A
III. PHENOL ANALYSIS
A short study was undertaken to develop a method for phenol
determination in diesel fuels and exhaust gas systems.
Two methods were investigated. A solvent extraction gas chromato-
graphic method to determine individual phenols and a solvent extraction
colorimetric method using 4-aminoantipyrene for total phenols.
Total phenol, after extraction with sodium hydroxide, is detected
rapidly and accurately down to 10 parts per billion by the colorimetric
method. Individual phenols by the extraction gas chromatographic method
are detected down to one part per million for phenol, cresols and xylenols
and five parts per million for tri and tetramethyl phenols. However, the
higher molecular weight phenols also present in diesel exhaust do not elute
from the gas chromatographic column. Therefore, we elected to use the total
phenol procedure.
A. Preparation of Phenol Concentrate by Caustic Extraction
For this program it is assumed that all phenols of interest are
extractable by aqueous sodium hydroxide. This would include many alkyl
substituted phenols, naphthols, indanols, and possibly higher number of ring
phenols.
A weighed sample (165 g) of diesel fuel or kerosene is extracted
three times with 0.5 N sodium hydroxide (25 ml each). In the case of exhaust
gases, a PWA solution is obtained by solvent washing all sample lines and
traps, solvent extracting the aqueous condensate, and the soot and diluting
the combined solutions to one liter. An aliquot (25 ml) of this solution is
then extracted with three 25 ml portions of 1.0 N sodium hydroxide. The
alkali extracts are combined and diluted to a known volume.
-------
54.
Appendix A
B. Total Phenol Analysis
The 4-aminoantipyrine method for total phenol was investigated.
In this procedure phenols in an aqueous solution react with 4-aminoantipyrine
at a pH of 10 +0.2 in the presence of potassium ferricyanide to form a
colored antipyrine dye. This dye is extracted from the aqueous solution
with chloroform and its percent transmission read at 460 nm. The concentra-
tion of the phenolic compounds is calculated as total phenol (CCH OH).
D 0
1. Color Development
The caustic washings are adjusted to a pH of 10 with phosphoric
acid, and diluted to 300 milliliters with water. Phenol I and II pillows*
containing various reagents needed for pH control and color development are
added to an aliquot of the solution further diluted to 300 ml. The colored
dye formed at room temperature is then extracted after two minutes with
30 milliliters of chloroform into a one-inch test tube. Percent transmission
at a wave length of 460 nm is measured by means of a Bausch & Lomb Spectronic
20 and compared with a previously prepared calibration chart to give the total
micrograms phenol present in the 300 milliliter sample taken for color
development.
2. Calculations
For diesel fuel, heating oil, kerosene:
micrograms phenol from calibration chart
PPm = weight of sample in grams
(total phenol)
For exhaust gas:
tjriginal sample vol.l
aliquot ) X Micrograms from calib. chart
(total pheno±;
* Obtained from the Hach Chemical Company, Ames, Iowa.
-------
55.
Appendix A
5. Application of Total Colorimetric Phenol Method
This colorimetric method was evaluated for various fuels.
The results are given in Table A-3. Each fuel was analyzed three times and
as can be seen, good agreement was obtained. Different sample weights of
each fuel were taken to insure that the phenols were quantitavely extracted
by the caustic.
C. Chromatographic Analysis
The combined caustic extracts are acidified and the phenols
extracted by three ethyl ether washings (about 40 ml each). Organic acids
are removed from the combined ether extracts with a small volume (about
10 ml) of saturated sodium bicarbonate solution. Finally, dissolved water
is removed from the ether by passing it through a glass column containing
anhydrous sodium sulfate.
The ether is evaporated, under nitrogen, on a steam bath to a
volume less than one milliliter. Orthochlorophenol (0.2 mg) was added for
use as an internal standard. An aliquot of this volume is injected into a
gas chromatograph equipped with a capillary column.
Figure A-4 shows a chromatogram of the phenols in an engine exhaust.
Table A-4 shows the gas chromatograph operating conditions and
Table A-5 shows approximate retention times and flame sensitivity of various
phenols.
D. Methods Comparison
The total phenol (4-aminoantipyrene) and gas Chromatographic
procedures are compared in Table A-3. The GC Method detects considerably
less total phenol than the 4-aminoantipyrene procedure. The likely
-------
o
o
X
o
O
O
m
z
o
r
S
m
w
m
r
m
x
3
m
r
Ethyl Ether
•0-Chloro Phenol
Phenol 654p.g
0-Cresol 6ug
2,6 Xylenol
P-Cresol
2-lsopropyl Phenol IIfig
3,5 Xylenol 4/xg
0-Ethyl Phenol 3u.g
M-Cresol 64/ig
2,3,5 Trimethyl Phenol 9/tg
'92
Unknown 196
(Assuming a Flame
Relative Sensitivity
of 50)
-------
TABLE A^3
TOTAL PHENOLS
4-Ami noanti pyrene
57.
Sample Size
Grams
1.5147
1.3052
2.0830
#2
Heating
Oil
Total Micrograms
Phenol
35
29
46
23
22.2
22.1
1.0793
1.1156
1.5058
Diesel
Fuel
30
30
40
27.8
26.9
26.6
1.0554
1.3023
1.7927
Kerosene
3
5
7
2.8
3.8
3.9
#2 Heating Oil
Diesel Fuel
GC ANALYSIS
7
19
-------
58.
TABLE A-4
GAS CHROMATOGRAPHIC OPERATING
CONDITIONS FOR PHENOL ANALYSIS
Instrument
Column
Substrate
Carrier Gas
Hydrogen Flow
Air Flow
Column Temperature
Detector
Injector Temperature
Detector Temperature
Splitter Ratio
Sample Size
Attenuation
Perkin Elmer 900
150' x .02" I.D. capillary
Didecylphthalate + 10% H3P04
Helium, 12#/square inch
PSI
PS I
130°C Isothermal
Flame lonization
250°C
250°C
1:90
6 yl
As needed
-------
59.
TABLE A-5
GAS CHROMATOGRAPHIC
SEPARATION OF PHENOLS
Approx. minutes
Component past injection F1 arne S e n s i t i v i ty (a)
o-Chlorophenol 4 0.45
Phenol 6 0.61
o-Cresol 7.5 0.66
2,6-Xylenol 7.7 0.68
p-Cresol 9 0.60
m-Cresol 9.5 0.60
o-Ethyl phenol 10.5 0.63
2,4-Xylenol 10.8 0.60
2,5-Xylenol 10.9 0.68
2,3-Xylenol 12.0 0.62
p-Ethyl phenol 12.9 0.60
iso-Propylphenol 13.0 0.70
3,5-Xylenol 13.4 0.69
3,4-Xylenol 16.0 0.61
2,3,5-Trimethylphenol 22.0 0.60
2,3,4,6-Tetra- 25.0 0.47
methyl phenol
(a) W. A. Dietz, J. Chromatog. Sci.. 10, 423 (1972).
-------
60.
Appendix A
explanation for this discrepancy is that the phenols in diesel fuels and
exhaust gases contain naphthols and other polynuclear phenols in addition
to alkyl phenol derivatives. These higher ring phenols do not readily
elute from the GC column. For example, 1-naphthol had not eluted from the
column by 60 minutes, whereas tetramethylphenol elutes in only 25 minutes.
On the basis of this limited study, and the fact that the total
phenol method takes considerably less time, it was decided to use the
total phenol 4-aminoantipyrene procedure for this program.
-------
61.
APPENDIX B
DIESEL ENGINE OPERATING PROCEDURES
The test procedures used for diesel engine operation are
published in the Federal Register, Volume 37, pages 24297 and 24310-24311,
November 15, 1972. The description of the test procedure and dynamometer
operation are reproduced below for each procedure:
1. Emissions Cycle - 13-Mode or Gaseous
§85.974-9 Test procedures.
The test procedures described in this
and subsequent sections will be the test
program to determine the conformity of
engines with the standards set forth in
§ 85.974-1.
(a) The test procedure begins with a
warm engine and consists of a prescribed
sequence of engine operating conditions
on an engine dynamometer with continu-
ous examination of the exhaust gases
(b) The test is designed to determine
the brake-specific emissions of hydro-
carbons, carbon monoxide and oxides of
nitrogen when an engine is operated
through a cycle which consists of three
idle modes and five power modes at each
of two speeds which span the typical
operating range of diesel engines. The
procedure requires the determination of
the concentration of each pollutant the
exhaust flow and the power output dur-
ing each mode. The measured values are
weighted and used to calculate the grams
of each pollutant emitted per brake-
horsepower hour.
(c) When an engine is tested for ex-
haust emissions or is operated for dura-
bility testing on an engine dynamometer
the complete engine shall be tested with
all standard accessories which might
reasonably be expected to influence
emissions to the atmosphere installed and
functioning.
§85.974—11 Dynamometer procedure.
(a) The following 13 mode cycle shall
be followed in dynamometer operation
tests of heavy-duty diesel engines:
Afoda No.
1
2
3
4
5 . ...
6
7
8
9
10
11
12.
Engine speed
Low idle
Intermediate
do
do , .
.. ..do
do
Low idle -
. Rated
do
.. ..do
do
do
Percent
load
0
2
25
60
75
100
0
100
75
60
25
2
13 Low idle
(b) During each mode the specified
speed shall be held to witJrn 50 r.p.m.
and the specified torque shall be held to
within 2 percent of the maximum torque
at the test speed. For example-, the torque
for mode 4 shall be between 48 and 52
percent of the maximum torque meas-
ured at the intermediate speed.
-------
2. Smoke Cycle
Appendix B
62.
§ 85.874-9 Test procedures.
The procedures described in this and
subsequent sections will be the test pro-
gram to determine the conformity of
engines with the standard set forth in
§ 85.874-1.
(a) The test consists of a prescribed
sequence of engine operating conditions
on an engine dynamometer with con-
tinuous examination of the exhaust
gases. The test is applicable equally to
controlled engines equipped with means
for preventing, controlling, or elimi-
nating smoke emissions and to uncon-
trolled engines.
(b) The test is designed to determine
the opacity of smoke in exhaust emis-
sions during those engine operating con-
ditions which tend to promote smoke
from diesel-powered vehicles.
(c) The test procedure begins with a
warm engine which is then run through
preloading and preconditioning opera-
tions. After an idling period, the engine
is operated through acceleration and lug-
ging modes during which smoke emission
measurements are made to compare with
the standards. The engine is then re-
turned to the idle condition and the ac-
celeration and lugging modes are re-
peated. Three sequences of acceleration
and lugging constitute the full set of ;
operating conditions for smoke emission ;
measurement.
(d> All emission control systems in-
stalled on or incorporated in a new motor
vehicle engine shall be functioning dur-
ing all test procedures in this subpart.
§ 85.874—11 Dynamometer operation
cycle for smoke emission tests.
(a) The following sequence of opera-
tions shall be performed during engine
dynamometer testing of smoke emissions,
starting with the dynamometer preload-
ing determined and the engine precondi-
tioned (§ 85.874-16(c)).
(1) Idle mode. The engine is caused
to idle for 5 to 5.5 minutes at the manu-
facturer's recommended low idle speed.
The dynamometer controls shall be set to
provide minimum load by turning the
load switch to the "off" position'or by
adjusting the controls to the minimum
load position.
(2) Acceleration mode, (i) The engine
speed shall be increased to 200±50 r.p.m.
above the manufacturer's recommended
low idle speed within 3 seconds.
(ii) The engine shall be accelerated at
full-throttle against the inertia of the
engine and dynamometer or alternately
against a preselected dynamometer load
such that the engine speed reaches 85 to
90 percent of rated speed in 5 ±1.5, sec-
onds. This acceleration shall be linear
within ±100 r.p.m.
(ill) When the engine reaches the
speed required in subdivision (ii) of this
subparagraph, the throttle shall be
moved rapidly to the closed position and
the preselected load required to perform
the acceleration in subdivision (iv) of
this subparagraph shall be applied. The
engine speed shall be reduced to the
speed of maximum rated torque or 60
percent of rated speed (whichever is
higher), within ±50 r.p.m. Smoke emis-
sions during this transitional mode are
not used in determining pmoke emissions
to compare with the standard.
(iv) The throttle shall be moved
rapidlv to the full-throttle position and
the engine accelerated against the pre-
selected dynamometer load such that the
engine speed reaches 95 to 100 percent
of rated speed in 10±2 seconds.
(3) Lugging mode, (i) Proceeding
from the acceleration mode, the dyna-
mometer controls shall be adjusted to
permit the engine to develop maximum
horsepower at rated speed. Smoke emis-
sions during this transitional mode are
not used in determining smoke emissions
to compare with the standard.
(ii) Without changing the throttle
position, the dynamometer controls shall
be adjusted gradually to slow the engine
to the speed of maximum torque or to
60 percent of rated speed, whichever is
higher. This engine lugging operation
shall be performed smoothly over a pe-
riod of 35 ±5 seconds. The rate of slow-
ing of the engine shall be linear, within
±100 r.p.m.
(4) Engine unloading. After comple-
tion of the lugging mode in subpsra-
graph (3) (ii) of this paragraph, the dy-
namometer and engine shall be returned
to the idle condition described in sub-
paragraph (1) of this paragraph.
(b) The procedures described in para-
graph (a) (1) through (4) of this fac-
tion shall be repeated until the entire
cycle has been run three times.
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APPENDIX C
TABLE C-l
GASEOUS EMISSION
SUMMARY -
- 13-MODE CYCLE
DDAD 3-53 Engine - Fuel 2-16
Modal Data
Mode
1
2
3
4
5
6
7
8
9
10
11
12
13
RPM
505
1816
1822
1820
1813
1817
500
2807
2797
2801
2795
2802
505
JSP-
0.3
2.7
16.8
33.9
50.7
67.9
0.2
86.9
65.0
43.7
21.9
3.2
0.3
% Load
4.0
24.7
50.0
74.7
100.0
-
100.0
74.8
50.3
25.2
3.7
-
Bsfc
Ib/BHP-Hr
4.597
2.497
0.606
0.455
0.433
0.450
6.180
0.466
0.484
0.558
0.815
4.862
4.203
Exh. Flow
Ib/hr
241
833
837
845
843
845
240
1222
1214
1206
1205
1209
239
Bsfc
0.5472
Fuel/Air^1'
Ratio
0.0054
0.0083
0.0123
0.0186
0.0268
0.0375
0.0053
0.0343
0.0266
0.0206
0.0150
0.0130
0.0050
13-Mode Cycle
BHP
31.48
Concentration, ppm
CO
263
325
238
213
400
5788
188
1150
250
175
175
175
188
Average,
CO
8.82
K02 N0
28 139
29 128
45 222
80 407
149 633
206 857
30 146
269 843
165 618
65 382
47 230
41 181
34 136
g/BHP-Hr^3)
H02 NO( g)
1.85 7.53
HC
190
271
240
238
250
140
157
275
275
265
266
279
190
HC
1.54
Mass, g/hr.
CO
27.6
116.8
85.1
76.1
140.6
1992.1
19.5
587.5
126.7
89.1
89.9
90.4
19.5
H02
4.5
15.6
24.1
43.0
78.8
108.6
4.7
204.4
125.7
49.8
35.8
31.5
5.2
NO(2)
21.9
68.8
118.6
218.0
335.7
448.2
22.5
642.0
470.6
291.4
176.4
140.0
20.8
HC
10.0
50.2
44.7
44.9
47.0
26.7
8.6
75.3
74.5
. 71.7
72.0
75.8
10.3
Smoke,
% Opacity
0.6
0.5
0.6
0.8
2.5
14.2
0.6
4.2
2.0
1.3
1.0
0.8
0.6
(1) Includes Scavenger Air.
(2) Calculated as N02.
(3) Calculated as Specified in Federal Register.
CD
CM
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TECHNICAL REPORT DATA
!?i ate ired >;\Hru£t\f»\s o>< the /^vcn.' before c
\7
EPA-4 60/ 3_____7__4j-02_2_
Study of Polynuclear Aromatic Hydrocarbon
Emissions from Heavy Duty Diesel Engines
5. REPORT DATE
July. 1974
8. PERFORMING ORGANIZATION REPORT NO.
R. S. Spindt
PS "rCS.V.N J OR "A'.'IZATION NAME AMD ADDRbSS
Gulf Research and Development Co.
P.O. Drawer 2038
Pittsburgh, Pa. 15230
12. SPONSORI
GENCY NAME AND ADDRESS
Environmental Protection Agency
2565 Plymouth Road
Ann Arbor, Michigan 48105
3. RECIPIENT'S ACCESS.Of*NO.
5. PERFORMING ORGANIZATION CODE
10. PROGRAM
NO.
11 CONTRACT/GRANT NO.
68-01-2116
13 TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15.3UP°LF\!FNTARY NOTES
Contract jointly funded by EPA and the Coordinating Research Council, Inc,
16. ABSTRACT • ' ' ' '•
A collection system consisting of a precooler, a glass fiber particulate
filter, and a Chromosorb-102 trap was used to collect PNA's from diesel exhaust.
PNA's are removed from the collection system by solvent washing and soxhlet
extraction, concentrated, and analyzed by thin layer chromatography. Total
phenols are analyzed by the 4-amino-antipyrene procedure.
Attempts to validate.the sample collection system using C^ tracers were not
successful. It is hypothesized that PNA's injected into the exhaust (i.e., tracers)
are largely destroyed by reactions with other exhaust components, while engine-
generated PNA's on or within soot particles survive these reactions. Radio tracers
also indicate that PNA-destroying reactions occur even after collection and extraction
from the sample system. Similar losses of PNA's do not occur with synthetic exhaust.
The fuel analyses showed that ASTM 1-D diesel fuels are nearly free of PNA
compounds. PNA levels in ASTM 2-D diesel fuels ranged from near zero to values that
reach the average concentration reported in motor gasolines.
DESCRIPTORS
KEY WORDS AND DOCUMb'NT ANALYSIS
:> IDENTIFIERS OPEX E.'J'-.iJ '. ERVo
Air Pollution
Diesel Engines
Polynuclear Aromatic Hydrocarbons
Diesel Fuels
PNA Analysis
PNA Sampling
Emissions
COS AT I Field/Group
13. D'.S '':''< 3 JTIOM STATEMENT
19. SECURITY CLASS (This Report/
Unclassified
21. NO. OF PAGES
63
Unlimited
L
20 SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Fo-m 2220-1 (9-73)
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