United States
Environmental Protection
Agency
Environmental Sciences Research
Laboratory
Research Triangle Park NC 2771 1
EPA 600 3-79
)79
Research and Development
SEPA
Oxidant-Precursor
Relationships
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7 Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on the effects of pollution on humans, plant and animal spe-
cies, and materials. Problems are assessed for their long- and short-term influ-
ences. Investigations include formation, transport, and pathway studies to deter-
mine the fate of pollutants and their effects. This work provides the technical basis
for setting standards to minimize undesirable changes in living organisms in the
aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/3-79-076
August 1979
OXIDANT-PRECURSOR RELATIONSHIPS
by
Edgar R. Stephens and Oscar P. Hellrich
Statewide Air Pollution Research Center
University of California
Riverside, California 92521
Grant No. R803799
Project Officer
Joseph J. Bufalini
Atmospheric Chemistry and Physics Division
Environmental Sciences Research Laboratory
Research Triangle Park, North Carolina 27711
ENVIRONMENTAL SCIENCES RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
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DISCLAIMER
This report has been reviewed by the Environmental Sciences Laboratory,
U. S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views
and policies of the U. S. Environmental Protection Agency, nor does mention
of trade names or commerical products constitute endorsement or recommenda-
tion for use.
ii
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* PREFACE
The air quality standard for ozone is exceeded by a wide margin
on many days of the year and in many locations around the country. The
inland area of Southern California is exceptionally vulnerable because
it is downwind of the Los Angeles/Orange County-megalopolis. Ozone, the most
toxic component, can only be controlled by reducing emissions of its precur-
sors. To establish standards for these precursors (hydrocarbons and nitro-
gen oxides), it is necessary to understand quantitatively the complex oxidant/
precursor relationship as it controls the real ambient atmosphere. The
project reported here was designed to provide "ground truth" data to support
this effort and for comparison with laboratory or computer models of photo-
chemical smog.
iii
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ABSTRACT
New methods of ambient air analysis were used to define more clearly
the relationship between oxidant (ozone) and its precursors (hydrocarbons
and nitrogen oxides). Nonmethane hydrocarbons (NMHC), nitrogen oxides,
ozone, and oxidants were measured at the same time and location (Riverside,
California). Such data are useful to establish the real world initial
conditions for the interpretation of chamber data and as input for modeling
studies.
An automated gas chromatograph was used for the direct measurement of
organic compounds containing three or more carbon atoms along with methane
and the three two-carbon hydrocarbons. Since the C3+ organics were measured
by a backflush technique, the error-magnifying step of methane subtraction
was avoided. Nitrogen oxides and nitric oxide were measured on the same
samples so that meaningful ratios can be calculated. By adding the concen-
trations of ethene and acetylene to the concentration of C%+ organics values
for nonmethane-ethane organic (NMEO) were obtained directly. The data in
this project provide two separate methods for estimating extent of reaction.
One is the ratio of nitric oxide to total nitrogen oxides. The other is the
ratio of ethene to acetylene. Both decrease as the reaction proceeds.
The ambient air data were entered into punched cards and are displayed
in this report as a series ofconditional joint distributions. The correla-
tions which appear range from excellent (ozone vs oxidant) to poor or
bimodal (ozone with nonmethane ethane organics [NMEO] or with nitrogen
oxides [NOx]). The ratio of NMEO to NOx was always higher than indicated by
inventories but showed a large scatter. The ratio of ethene to acetylene in
unreacted samples was about 1:1, the same as ten years ago. Samples which
iv
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were reacted as Judged by ozone concentration showed depletion of ethene as
compared to acetylene because of its greater reactivity. No depletion of
NMEO with respect to acetylene could be detected.
Further development of the backflush technique for direct measurement
of NMHC or NMEO is recommended along with development and exploitation of
the conditional joint distribution analysis.
This report was submitted in fulfillment of grant No. R803799 by the
Statewide Air Pollution Research Center, University of California, Riverside
92521 under the sponsorship of the U.S. Environmental Protection Agency.
This report covers a period from July 21, 1975 to September 30, 1978 and
work was completed September 30, 1978.
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CONTENTS
Preface ill
Abstract iv
Figures viii
Tables ix
Abreviations and Symbols xl
Acknowledgments xii
1. Introduction 1
2. Conclusions 11
3. Recommendations 13
4. Methods 14
Hydrocarbon analysis 17
Nitrogen oxides 25
Oxidant and Ozone 27
PAN 29
Light intensity 29
Data reduction 30
5. Results and Discussion 31
Comment on tables 31
References 57
Appendix 58
Back Extrapolation Procedure .... 58
vii
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FIGURES
Number Page
1. Surface radiation inversions like this (unusually shallow)
one are almost always present near dawn. They concentrate
pollutants emitted in the early hours in a very small volume,
but are mixed when solar energy heats this small volume 3
2. Three oxidant (KI) analyzers in different locations show
the spatial uniformity of the oxidant field during a severe
episode 5
3. Diagram illustrating the oxidant isopleth strategy 9
4. To insure comparability of hydrocarbon and NOjj analytical
data both instruments drew samples from a 20 liter integrating
bottle 16
5. An eight-port, two-position automated sampling value is at
the heart of this hydrocarbon analysis chromatograph 19
6. Representative hydrocarbon chromatograms showing morning,
midday, and evening pollution 21
7. Peak height and peak area gave fair correlations with concen-
trations of a commercial gasoline ..... 23
8. Peak heights correlated well with peak area for ambient air
sample 24
9. This fall day shows the high values of NOX created by
morning traffic which disappears in midday when the radiation
inversion breaks 26
10. Very high NOX/NO values on a December morning. Almost all
the NOX was NO. The spike at 0800, caused by a nearby tractor,
led to an NO value which exceeded the NOX 26
11 The NOX/NO traces after installation of the integrating bottle.
Both traces are much smoother than in Fig. 9 and 10. The per-
sistent overnight NOX must represent previous days pollution
whereas the NO (note that it parallels the NOX) represents new
infusions of combustion gas 27
12. Typical ozone and ultraviolet radiation record. Compare NOX
in Figure 9 28
13. Summer record of ozone and ultraviolet 29
viii
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TABLES
Number Page
1. The weight ratio NMHC/NOX 8
2. Summary of measurements 15
3. Calibration with light hydrocarbons 23
4. Calibration with gasoline 25
5. Joint distribution of non methane/ethane organics
(ethene plus acetylene plus back flush peak) and NOX
[NO + NOx + PAN + nitrates (?)] weight as N02-
a. all reduced data 36
b. after installation of integrator bottle 37
c. for ozone exceeding the standard 38
d. for unreacted air (high nitric oxide) 39
e. for morning hours 40
f. for evening hours 41
6. Joint distribution of non methane/ethane organics (ethene
plus acetylene plus back flush peak) and NO (weight as NO) 42
1* Joint distribution of non methane/ethane organics with
ozone 42
8. Joint distribution of non methane/ethane organics with
acetylene a) all reduced data b) ozone above standard ... 43
c) unreacted air, NO above 60 ug/m^ (0.05 ppm) 44
9. Joint distrubtion of non methane/ethane organics with
ethane a) all reduced data, b) morning, c) evening .... 45
10. Joint distribution of non methane/ethane organics with
methane a) all reduced data, b) morning, 46
c) evening, d) ozone above standard 47
11. Joint distribution of acetylene and ethene.
a. all reduced data
b. data with integrator bottle 48
c. data for ozone above standard
d. data for high NO (unreacted) 49
12. Joint distribution of acetylene and methane.
a. . all reduced data
b. morning . ............. f .' 50
c. evening
d. unreacted air NO >60 ug/m^ .............. 51
e. ozone above standard ..;...' 52
ix
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Number Page
13. Joint distribution of ethane and methane.
a. all reduced data
b. morning .......... 53
c. evening ................. 54
14. Joint distribution of ozone and oxidant 55
15. Joint distribution of ozone and NOX
a. all reduced data 55
b. NMEO above standard 56
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ABREVIATIONS AND SYMBOLS
NMHC - non methane hydrocarbon
NMEO - non methane ethane organic
SCAB - South Coast Air Basin
•*
GARB - California Air Resources Board
SCAQMD - South Coast Air Quality Management District
xi
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ACKNOWLEDGMENTS
The support and helpful criticism by the two project officers, Dr.
Basil Dimitriades and Dr. Joseph Bufalini is deeply appreciated.
xil
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SECTION 1
INTRODUCTION
Ozone is considered to be the major health hazard in photochemical
smog and so control strategies have been directed toward reducing ozone
exposures to acceptable levels. This toxic compound is a product of a very
complex reaction of primary pollutants (hydrocarbons and nitric oxide)
which are not themselves highly toxic. This means that control of ozone
exposure depends on control of hydrocarbon and nitric oxide emissions.
Emission standards must be stated quantitatively so it is necessary to
develop a quantitative relationship between emissions of primary pollutants
and subsequent ozone exposure. This has been a very difficult problem
because the complexities of the photochemistry are compounded with those
of meteorology, sunlight, and sources. In the actual event a non-methane
hydrocarbon (NMHC) standard of 160 micrograms per cubic meter was es-
tablished based on a review of ambient air data. Since hydrocarbon is a
precursor of oxidant, the 6-9 AM average concentration was specified in
the expectation that high hydrocarbon concentrations at this hour would
lead to high ozone values later in the day.
The term "oxidant precursor" has quite a long history. It was first
used to describe the fact that early morning air could be irradiated with
artificial sunlight to produce oxidant. This experiment was done at the
Stanford Research Institute and at that time (the mid-50s) there was no
t
clue as to the nature of the precursor. Within a few years it became
-------
evident that unirradiated morning air could be described as dilute auto
exhaust even though it had none of- the symptoms of photochemical smog.
But irradiation of this "precursor" with artificial sunlight did produce
oxidant. In later years, use was made of this ability of stable, early
morning weather conditions to trap unreacted auto exhaust to study the
nature of the hydrocarbon mix which was then present. Although this type of
atmospheric stability will trap auto exhaust and other pollution in the
early morning hours, it is not always followed by an afternoon of high
photochemical smog because the radiation inversion responsible for early
morning trapping (an example is shown In Figure 1) is destroyed by sunlight
more rapidly than sunlight can convert exhaust into photochemical oxidant.
In fact, one striking result was that in these early morning samples, even
unreactive auto exhaust components such as acetylene were present in
substantially higher concentrations than in afternoon samples In which smog
was fully developed. In spite of the tenuous relationship between early
morning concentrations of hydrocarbon and the oxidant history of the
subsequent afternoon, the air quality standard for hydrocarbon was written
in terms of the 6-9 AM concentrations of hydrocarbons (1). This was used
not only to set the air quality standard for hydrocarbon but to estimate the
degree of hydrocarbon control needed to attain the oxidant air quality
standard. Both the needed degree of control and air quality standards can
also be estimated using chamber irradiation data (2).
The new approach represented by this project was not meant to be a
substitute for either chamber studies of oxidant formation in synthetic
mixtures or for mathematical modeling of the photochemical reaction. It is
instead designed to be a kind of "ground truth" measurement against which
-------
5-
Ui 3
O
I -
hi 500
CO
-1000
LiJ
- 5OO
RUBIDOUX
CAL SURFACE
I
ADIABAT ,\
0 5 10 15 20 25
AIR TEMPERATURE °C (25 NOV 77)
30
Figure 1. Surface radiation inversions like this (unusually shallow) one
are almost always present near dawn. They concentrate pollutants
emitted in the early hours in a very small volume, but are mixed
when solar energy heats this small volume.
other methods of devising air qualtiy standards and control strategies can
be compared. If all approaches could be reconciled to yield one strategy,
we would be in a much stronger position to define and to defend that strategy.
One unknown which can never be resolved by either chamber studies or
modeling is the extent to which the mixture which is injected into a given
atmosphere varies from day to day and from place to place. Sometimes it
has been assumed that there are very wide variations in the hydrocarbon to
NOX ratio in the precursor mixture and even within in the hydrocarbon mix
itself. Sound control strategy requires a knowledge as Nto whether this
3
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needs to be taken into account. Our studies of light hydrocarbons indicate
that the hydrocarbon mix itself is reasonably uniform from day to day and
from place to place, that is, the relative amount of individual hydrocarbon
are, except for the more reactive hydrocarbons or for samples taken near
sources, are always about the same (3). Another objective is to see if the
ratio of total nitrogen oxides to nonmethane hydrocarbon is significantly
variable from day to day. The ambient oxidant field appears to be much more
uniform in space than might have been thought, although it shows quite
random fluctuations with time. Comparisons of nearby oxidant recorders show
that these variations are real but they are fairly uniform over a few
hundred feet of space. One record is shown in Figure 2 in which traces from
three different locations on and near the Riverside campus are compared.
Although the absolute levels are not in close agreement, the variations with
time are remarkably similar.
The hydrocarbon standard was established with the aid of a plot of
ambient air oxidant maxima against nonmethane hydrocarbon concentrations
measured at 6-9 AM of the same day. An upper boundary drawn above this
scatter pattern was taken to give the maximum oxidant which could be
produced from this amount of hydrocarbon precursor (4). Such plots were
used to set the hydrocarbon standard at a value required to meet the
oxidant standard of 0.08 ppm (160 ug/m^). They were also used to derive
a Z control diagram which became the "Appendix J" which was used to design
control strategy (5)* Although this approach had the merit of being based
on actual polluted air data it could be and was criticized on a number
of grounds. Perhaps the most serious is that the oxidant and its precursors
are measured on different air parcels.
-------
WEATHER
STATION
(Max. Temp. = II3°F)
OXIDANT loom)
-0.6
APCD 0.60 (ppm) © 350
T4lppm
TOP OF ,^
TOWER (~
-.55 ppm
BOTTOM OF
TOWER
.49 ppm
t 6AM
SUNRISE
SAM
OA*
T 1 1
NOON
3PM
' 6PU '
SUNSET
' i "7 ' i
9PM
MONDAY 13 SEPT. 1971
Figure 2. Three oxidant (KI) analyzers In different locations show the
spatial uniformity of the oxidant field during a severe episode•
The various procedures used to estimate the degree of control required
for auto emissions give answers varying between 90 and 97% or even more
(6). While this may seem to be an acceptably narrow range, when translated
into emissions standards it gives a variation in allowable emission of
more than 3 to 1. This is far from trivial to the automotive engineer.
The assumption that the measured oxidant is produced by the measured
early morning NMHC/NOX is especially serious when the use to which these
curves (scatter patterns) have been put is remembered. One draws a boundary
-------
around the scatter pattern,and extrapolates to the oxidant air quality
standard. The position of the boundary is determined by those few points
at the lowest values of NMHC and oxldant. These are also the points
•oat subject to error because of their small values. The HMHC (nonmethane
hydrocarbon) is especially vulnerable if it is estimated by subtracting
methane from total hydrocarbon.
Also needed is a method for back extrapolation in time for an air
parcel which has had a chance to react and develop ««•»-» «mim oxidant. The
objective, of course, would be to state what HHHC and HOg in the unreacted
state corresponded to this measured oxldant. This can be done well enough at
least to provide a better comparison with chamber data than the data so far
used* for back extrapolation of hydrocarbon values a procedure first used
In Befereace (3) was adopted. In that paper the relative amounts of three
hydrocarbons of widely differing reactivity (acetylene, ethene, and propene)
were used to estimate that a Riverside smog had been photoreacted for six to
eight hours. This estimate was *KCT combined with data on photolysis of
ambient air to estimate that about one-third of the HMHC had reacted. A
fuller discussion is given in the appendix.
The chemiluminescent analyzer used for HO/HOg analysis should auto-
matically "back extrapolate*1 the HOg concentration since the converter
used to obtain the NOg values reduces not only W>2 but PAR and probably
nitrate to BO (7). In the HO^ mode, the instrument therefore probably
gives a good measure of the initial oxides of nitrogen. Catalytic reduction
then constitutes back extrapolation*
In this program of data analysis much use is made of ratios of pollu-
tants, partly because they are not affected by dilution and partly because
-------
they reveal special characteristics of the air sample (for example, extent
of photoreaction). A ratio of major importance is that of hydrocarbon
(NMHC) to nitrogen oxides because of the use of oxidant isopleths derived
from chamber experiments or modeling. Understanding of this relationship is
vital to sound development of control strategy, air quality standards, and
emission standards. Debate about emission standards will only end when
"clean air" is achieved. Recent developments in ambient hydrocarbon analysis
were exploited to provide a sounder data base for understanding the real
atmospheric situation. Under EPA grant R803799 and after much difficulty, a
backflush chromatograph was developed to measure hydrocarbon in ambient air.
This instrument measures (separately) methane, ethane, ethene, acetylene and
higher hydrocarbons on a single small sample of ambient air. This permits
for the first time direct measurement of the widely discussed but infre-
quently measured nonmethane hydrocarbon (NMHC).
While dispersion models permit the estimation of ambient concentrations
from source inventories they depend on parameters which are not usually
known accurately. This makes comparison between ambient air quality and
and emission inventory data of limited value. Ratios of pollutant con-
centrations are not affected by dilution so the emphasis in this project
has been on comparison of ratios. It should be possible to reconcile
at least approximately, the ratio of NMHC to NOX found in the atmosphere
with that estimated from emission inventories. Any gross discrepancy
should be explored further. Since inventories are always stated in weight
units to accommodate mixtures of unknown average molecular weight it is
necessary to express ambient air concentrations the same way. By long
custom, nitrogen oxides, NOg, is expressed in weight units as though it were
-------
all N02 even though combustion sources emit primarily HO. In this project,
NO has been expressed by weight as NO; but NOg has been expressed as H0£ to
facilitate comparison with emission inventories*
Table 1 shows inventories which have been published by various agencies
for various areas in recent years. The weight ratio covers a range from
0.77 to 1.45 which is small considering that a number of years are covered
and the lower figure is for cars only. It is also convenient to express
hydrocarbon concentrations by weight since the flame ionization detector
responds roughly according to weight and it can then be calibrated without
regard to molecular weight.
TABLE 1. THE WEIGHT RATIO OF
Year
1972
1973
1977
1977
HMHC/NOg « Ratio
Tons/Day '
8.58 x 104 . ,.
6.«8 x 10* 1<41
i^ - 1.45
1210 x'*a
1506.7 . M
1505.7 1>0°
OI/MILE
«
Area Agency
>
USA EPA
SCAB* GARB
SCAB* SCAQMD
Gasoline SCAQMD
Vehicles
Ref.
(8)
(9)
(10)
(ID
*SCAB - South Coast Air Basin
This inventory ratio of about 1 may be compared with chamber data
by reference to two papers in the "Internation Conference on Photochemical
Oxidant Pollution and Its Control," EPA-600/3-77 00Ib, a meeting held in
8
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September 1976. The paper by Dimitriades (#18.2, p. 871) describes "An
alternative to the Appendix J method for calculating oxidant and NC>2
related control requirements." The following paper by Dodge (p. 881)
explains the use of modeling techniques to supplement chamber data in
development of this approach. The key concept is the use of the oxidant703
isopleth diagram reproduced here (2).
OXIDANT/OS ISOPLETHS DERIVED FROM COMBINED USE OF
SMOG CHAMBER AND PHOTOCHEMICAL MODELING TECHNIQUES
OXIDANT/03, ppm
.08 .20 3O .40.50 .55 £O .65
1.0
NMHC, ppm C
2.0 3.0
4.O
5OO
1000
I50O
2000
2500
C2H4+ C2H2+ C3+^g/ M*
5.0
Dimitriades EPA-600/3-77-0015
Figure 3. Diagram illustrating the oxidant isopleth strategy.
-------
To bridge the gap to emission inventory data weight/m-^ scales have
v
been added to this diagram (the two ratios given on the plot are by moles).
To make use of this plot a data base of the HMHC and HOg values in real
polluted air is required. As stated in Dimitriades' paper, "The requisite
data can be obtained through ambient measurements that must be sufficiently
abundant to provide a reliable measure of the range of the MMEC-to-NO^
ratio." The NMHC/NOg ratios of 5.6 and 8.0 given on the above plot must
be multiplied by 14/46 = 0.304 for comparison with inventory weight ratios.
The resulting values (1.7 and 2.43 gm fflHC/goBOg) are both higher than the
inventory ratios given in Table 1«
Data for the two highest oxidant days of late fall 1976 are plotted
on the above oxidant isopleth d1agr»» as Points A and B. At point A (Satur-
day, Nov. 20, 1976, 1400-1600 PST) 4be Measured oxidant was .18 ppm, very
close to the 0.20 contour from the «*;BffM!T data* Point B (Sunday, Hov. 21,
1976, 1600-1700 PST, a day on which eye Irritation was noted) the oxidant
was 0.21 ppm. On this day (at 1500) the C^EL^/C^L2 r«tio fel1 below 0.4
for perhaps the only tine in this set of records, indicating a high degree
of reaction. On Saturday (point A) it was Just below 0.6, also indicating
a high degree of reaction (about half of the ethylene consumed).
10
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SECTION 2
CONCLUSIONS
The mass of data collected during this project vas summarized In the
form of joint distributions, some of which were conditional. This method of
data study proved to be a useful way to analyze ambient air data. Some such
distributions, which were expected to be highly correlated, are so; for
example ozone/oxidant. Other distributions show greater scatter, which may
be due in part to lack of precise time synchronization between different
Instruments.
The crucial non-methane ethane organic (NMEO) vs BO^ distributions show
large spread, perhaps due in part to deficiencies in the time synchroniza-
tion. This is true for all the conditions tested. The ratios of
f
are all several times larger than those suggested by emission inventories.
This is true even for mixtures whose high nitric oxide content suggests that
they were unreacted and for 6-9 am samples.
Non-methane ethane organic and acetylene are quite closely correlated
and show no depletion to the former with high oxidant. Here there was no
possible time synchronization error because the two quantities derive from
the same sample and analyzer. The good correlation also suggests that
these two components come from the same source (auto exhaust ) . Ethene and
acetylene are also closely correlated for the same two reason. Components
which come from different sources (for example acetylene and methane) show
a lesser degree of correlation because they are similarly affected by
>
11
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atmospheric stability.
The higher reactivity of the former hydrocarbon is reflected in a
reduction of the ratio in those samples with high ozone* In unreacted
samples the weight ratio was about 1:1 the same as it was ten years ago.
Joint distributions of ozone with NMEO and NOX are bimodal reflecting
the difference between reacted and unreacted samples. This is attributed
more to meteorology than chemistry.
12
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SECTION 3
RECOMMENDATIONS
.*
The backflush gas chromatographlc procedure should be further developed
to provide better data on hydrocarbon pollution which excludes the naturally
occurring and unreactive methane* This method avoids the subtraction
step which magnifies errors* For maylnmm utility automated peak integration
should be added to automated sampling*
Time synchronization of sampling should be carefully controlled to
avoid data scatter where correlations, ratios or Joint distributions are to
be used in data reduction.
Concentration intervals should be carefully chosen in joint distribu-
tion analysis to avoid fictitious broadening of well correlated data. This
f
method of analysis appears to have great potential for study of polluted
air.
Concentrations should be expressed in weight units to facilitate
comparison with inventory data.
Computer analysis using conditional joint distributions should be
developed further as a method of study of polluted air.
13
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SECTION 4
METHODS
UCR has maintained a weather station for many years in connection with
its agricultural research. It is housed in a one room, air conditioned,
cinder block building set in the middle of an agricultural field. This is a
good sampling site since it is accessible, yet somewhat removed from heavy
traffic. Air monitoring instruments have been operated in this house
periodically for several years, the principle ones being a conlometric
oxidant analyzer (Hast) and an automated PAH chromatograph. Oxidant levels
correlate fairly veil with those reported by state and country «E«»Tirt«>a in
>
the area.
The air samples were taken from an existing Installation in the weather
station. The sample entered a 4** diameter aluminum irrigation pipe stack
at a point about 30 ft above the ground. The sample pipe entered the
building through the roof and was divided by a glass T" into two 2" di-
ameter glass pipes, 10' and 15' long respectively. Each glass pipe was
vented to the roof to a 150 CFM blower. Table 2 summarizes the five instru-
ments which were operated during this program.
One sample pipe supplied the PANanalyzer (electron capture gas chro-
ma tograph), oxidant analyzer and an ultraviolet ozone analyzer (Dasibi); the
other supplied the NO-NOg analyzer (TECO) and the hydrocarbon gas chro-
ma tograph. Each instrument obtained its sample through a 1/8" diameter
Teflon tube.
14
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Midway through the program (April 19, 1977), a 20-liter glass bottle
-i
was placed in the sample line to the NO-NOX analyzer and the hydrocarbon
chromatograph instruments. The flow through the bottle was provided by the
NO-NOX instrument sampling pump which pulls 50-56 /hr (1.8-2 SCF per hour)
. i
TABLE 2. SUMMARY OF MEASUREMENTS (ALL ON A CONTINUOUS OR AUTOMATIC BASIS).
1. Hydrocarbons - Gas chromatography with flame ionization. Direct in-
jection measurement of methane, ethane, ethene, acetylene.
Hydrocarbons of 3 or more carbons as one peak in back flush mode.
2. Nitrogen Oxides - By ozone chemiluminescence. This measures NO
and NOX and the latter is taken to be total oxidized nitrogen.
3. Ozone - By ultraviolet photometer. (Dasibi)
4. Oxidant - By coulometric KI method. (Mast)
5. TJV Intensity - By recording tJV meter. (Eppley)
thereby providing a 22-24 minute residence time for the sample in the
bottle, as shown in Figure 4.
The hydrocarbon analysis reported in the previously cited reference
(3) was carried out opportunistically, sporadically and manually. No
paraffins higher than C^ nor olefins higher than C$ were measured. It
was therefore necessary to estimate the higher molecular weight hydrocarbons.
A new backflush chromatograph made it possible to monitor methane, the
two-carbon hydrocarbons and C$+ hydrocarbons by automated direct sample
injection followed by backflush. An eight-port valve automatically operated
by a "valve minder" injected a 4.4-ml sample of ambient air.
15
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Samples for the hydrocarbon chromatograph and PANanalyzer were taken at
".••»'.—
15 minute intervals on the hour an4 quarter hour, using timers and solenoids
.v"w~ *"
which permitted unattend&d, around the clock operation.
AMBIENT AIR
IN
I
BACK FLUSH
HYDROCARBON
CHROMATOGRAPH
(At = ISmin)
FLOW=I L/MIN
ANALYZER
20 LITER
BOTTLE
Figure 4. To insure comparability of hydrocarbon and NOx analytical data
both instruments drev samples from a 20 liter intergrating
bottle.
The analytical data were recorded first on strip charts since automa-
tion of the chromatographic output would be difficult. Data were then
transferred to punch cards. Five hydrocarbon measurements with five other
variables every 1/4 hour adds to 40 points per hour or 960 per day. This
16
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made machine manipulation necessary. It also greatly facilitates grouping
the data points according to ethene/acetylene ration (indicative of degree
of reaction) or other variables.
HYDROCARBON ANALYSIS
"Conventional" methods of measuring NMHC rely on separate measurement
of total hydrocarbon (THC) and methane followed by mathematical subtraction.
The fact that methane, especially in relatively clean air, is a large part
of the total makes this procedure vulnerable to the errors of subtracting
two numbers which are both large compared to their difference. This proce-
dure can produce apparent negative concentrations of NMHC if there are small
errors in either THC or methane or if they are measured in separate samples.
Negative values can clearly be rejected as spurious but their occurrence
makes the accuracy of all positive values (especially the small values near
the air quality standard) quite questionable. The background level of
methane is about 1.38 ppmC and the aif quality standard is 0.24 ppmC. An
air sample containing exactly 0.24 ppmC of NMHC in addition to background
methane would have a total of 1.62 ppmC. A small error in either the
methane or total hydrocarbon measurement will produce a much larger percent-
age error in the NMHC. Any procedure which uses separate samples for the
two measurements will be susceptible to such errors.
For these reasons it was decided to use a backflush technique for the
measurement of higher hydrocarbons directly, rather than by difference, so
that the same sample of air could be used for both. This represented a
substantial extrapolation of prior techniques since freeze-out concentration
could not be used with automated sampling and backflush. With the sample
.size thus restricted to 4.4 ml the peaks are small and noise and drdft must
17
-------
be kept to a minimum. Since the methane peak is much larger than the other
four peaks It is recorded on the second channel of a two-pen recorder at a
reduced sensitivity.
The principal problems encountered in setting up this method were
in maintaining a flame in the detector and a stable baseline while reversing
the column flow. The surge of carrier gas which accompanies reversal of
flow snuffs the flame unless a buffer is inserted between the sampling valve
and the flame detector.
The eight-port sample valve (Carle Model 2012) used in the configuration
shown in Figure 5 provided direct analysis of methane, ethane, ethene, and
acetylene. By using the backflush procedure the remainder of the hydrocar-
bons (63 and higher) were measured as a single peak. In the "sample and
backflush" position the column was backf lushed for 12 minutes, the sample
J.
loop was purged with sample air starting two minutes before the end of this
period. In the last minute, the pump was turned off to allow the loop to
equilibrate. In the "inject" position the contents of the sample loop
were injected into the column to determine methane and the G£ hydrocarbons
in a three minute chromatogram.
Various restrictors were tried In the line between the valve and the
flame detector to prevent flameout. These included a length of capillary
tubing, tubing filled with Teflon beads, and various short columns contain-
ing Poropak N packing. Most successful was a 7.5 cm-long column filled with
50/80 Foropak N, which prevented flameout and provided the stable baseline
needed for our operating conditions which were chosen to maximize Instrument
sensitivity.
For much of the program the instruments was plagued with a cyclic
18
-------
drift often superimposed on another cyclic drift having a different time
interval, and a random drift pattern affecting the baseline. The first
cyclic drift, up on analysis, down on backflush, was thought to be caused by
differences in flow which were not measureable. Elimination of the problem
was attempted by shortening all capillary lines 'to the sample valve to
FLAME
DETECTOR
90 ml Hg/min
410 ml
COLUMN
3.05m x
2.16 mmid
BUFFER COLUMN
(7.5cm x 2.16 mmid)
50/80 MESH POROPAK N
50/80 MESH POROPAK N
64 °C
CARRIER 100ml N2/min
SAMPLE
PUMP
4.4ml SAMPLE
LOOP
Figure 5. An eight-port, two-position automated sampling valve is at the
heart of this hydrocarbon analysis chromatograph.
minimize line restrictions. To determine if the drift may have been caused
by contamination the sample valve was moved 180 in relation to all
plumbing connections. Neither the capillary nor Teflon bead buffer column
19
-------
controlled the cyclic drift. As previously mentioned, only when the Poropak
N column buffer was Installed was the cyclic drift controlled.
v«
Another problem affecting the instrument was thermal cycling caused
\
by the room air conditioner. This problem was minimized when a small
cardboard box was placed over the flame detector, a second cardboard box was
placed over the whole instrument, and a deflector was attached to the room
air conditioner to eliminate drafts around the chromatograph.
Baseline shifts, usually going completely off scale, were also caused
by a recurring problem with the valve actuator. The valve actuator failed
to turn the sample valve properly to its stop position, usually going
too far in one direction and causing the valve to "cycle," or travel a
short distance forward and back at one stop position, and then not going far
enough at the other valve position, stopping ajl carrier gas flow and
upsetting the thermal and ion balance in the flame detector. Modification
of the valve actuator travel limit cams and repositioning the actuator were
required to eliminate this problem.
Each injection yields a two part chromatogram which gives five measured
peaks: methane, ethane, ethene, acetylene and higher hydrocarbons and other
organics in the back flush mode. Since methane values exceed the world-vide
background value of 890 ug/m^ while the two carbon hydrocarbons are often
less than 10 ug/m^ it was necessary to record the signal at full (XI) and
reduced (x20) sensitivity. A typical sequence is shown in Figure 6 for
15 July 1977. Only the methane is detectable on the lower trace; on this
time scale the peak width is not dlscernable. The upper trace shows the two
carbon hydrocarbons from the direct Injection followed by the higher hydro-
carbons backflushed through the detector after column reversal (labelled as
20
-------
C3+ hydrocarbons). The peaks for all five components are of adequate
size for measurement. Some characteristics of polluted air are evident in
this tracing:
1) The ratio of the reactive hydrocarbon ethene to the unreactive
hydrocarbon acetylene is appreciably lower in the midday reacted
sample as compared to morning or evening sample.
2) The unreactive acetylene and ethane are larger in the morning
0700 0715 0730 074S 1245 1300 1315 I33O 1345 1600
PACIFIC STANDARD TIME, 15 JULY 1977
1815
1830
1845
Figure 6. Representative hydrocarbon chromatograms showing morning* midday,
and evening pollution.
21
-------
than during the midday. ,'
It does not clearly show on the sample chromatograms but the methane
peak is preceded by another peak which seems to be related to the presence
of carbon monoxide. At higher chart speeds the two peaks are seen to be
nearly completely separated. This might prove useful but there is no
apparent interference with the methane measurement.
Calibration
Both commercial calibration gas mixtures and special dilution mixes
were used for calibration of the one and two carbon hydrocarbon peaks.
The latter were prepared in low pressure oxygen tanks and were stable
and suitable. Typical calibration results are shown In Table 3. The
last column gives the concentration In (ug/M^) which corresponsponds to one
chart division of pen deflection. Thus it corresponds roughly to the minimum
detectable quantity.
Concentrations as low as a few ug per H^ of the Cy* (about 5 ppb)
and less than 100 ug per M^ (0.2 ppn£) of the C$*~ hydrocarbon are
detectable. Quantitation of the backflush peak presented some problems.
Finally, a sample of gasoline was used for calibration, Figure 7. This gave
a broader peak than propane, as would be expected, but peak height corre-
lated well with peak area (see Figure 8) for ambient air samples so peak
height was used to calculate concentrations.
The propane/methane gas mixture gave a backflush peak, due to propane,
which was quite sharp whereas the ambient air peak was somewhat broader
with some tailing. A mixture of Cg hydrocarbons containing 0.10 ml
2,2,4-trimethyl-2-pentene, 0.35 ml xylene, and 0.55 ml 3-methyl heptane was
22
-------
TABLE 3. CALIBRATION WITH LIGHT HYDROCARBONS.
Concentration
Compound
Methane
Methane
Ethane
Ethene
Acetylene
Propane**
Propane**
ppb*
1160
58.8
49.8
51.0
55.0
46.2
607
ug/m3
757
38.3
60.9
58.3
58.3
82.9
1089
Peak height
scale
divisions
34
35.7
25.5
32.2
26.8
6.2
46
Att.
X
20
1
1
1
1
1
2
Response K
mv
6.80
0.357
0.255
0.322
0.268
0.062
0.920
mv/ug/m-1
8.98 x 10~3
9.32 " "
4.19 " "
5.53 " "
4.60 " "
0. 748" "
0.844" "
. 3
u«/m
division
1.11
1.07
2.39
1.81
2.17
13.4
11.8
*ppb by moles (298 K, 1 atm)
**backflush mode
Z
o
50
40
- 30
UJ
I
UJ
Q.
20
10
I
(M
0.90 .£
0.80 <
Ul
0.70 JE
0.60 *
0.50 Ul
0.
0.40
O.3O
0.20
0.10
2000
4000
6000
8000
yLLg/M3GASOLINE VAPOR (GASAMAT 0.73 gm/ml)
Figure 7. Peak height and peak area gave pair correlations with concentra-
tions of a commercial gasoline.
23
-------
prepared as a standard reference mixture to simulate gasoline vapor, but it
was impossible to obtain repeatable results when sampling ppb concentration
dilutions of this mixture. .Similar problems were encountered when using
xylene alone and n-heptane alone.
More repeatable data were obtained when small quantities of gasoline
were vaporized in a 20 L bottle and dilutions of this mixture were sampled
by the GC. Such data are shown in Table 4. Some differences in peak
RELATIONSHIP OF AMBIENT AIR BACKFLUSH
PEAK AREA TO PEAK HEIGHT
_
X
UJ 4
0_ ^
0
*
. ^ •
* »* •
• •*
*•*•
•
0 J^*
* _ ^
• " *
•flT 90 DATA POINTS
••••"* NOV 22 1976
^^b ^^W
^^^f
» | | | | 1 1 1 1 1 1 1 1
.04 .08 .12 .16 .20 .24
PEAK AREA, in2
Figure 8. Peak heights correlated well with peak area for ambient air
sample.
24
-------
shape compared to ambient air are still observed, gasoline being somewhat
broader at the base than the ambient air peak. These broader peaks resulted
in a sensitivity about one order of magnitude lower for the gasoline.
TABLE 4. CALIBRATION WITH GASOLINE.
Concentration
ug/m^
1830
3660
3660
3660
5550
7322
Peak Height
division
10.0
19.6
20.9
22.3
34.2
47.8
Peak Area
in2
0.144
0.315
0.303
0.338
0.574
0.851
Regular grade "Gasamat" brand gasoline
Specific gravity: 0.73 gin/ml
NITROGEN OXIDES
A chemiluminescence analyzer (TECO) was used to measure NO and total
nitrogen oxides (by thermal conversion to NO). Typical records are shown in
Figures 9, 10 and 11. For the 15 July 1977 record, the integrating bottle
was in place and gave a much smoother record than the two earlier ones.
Most users of these instruments wish to convert only N0£ to NO so that the
difference NOX-NO can be equated to N02* Since PAN is a fragile molecule
there is probably -no way to prevent its conversion to NO so the NOg-NO at
least must be regarded as N02 + PAN. There is evidence also that nitrates
and nitrites will also be reduced by NO by the catalyst. The NO^ records
shown in the figures both indicate high NOg levels in morning and evening
•%
with much smaller values in midday. The 17 December 1975 record shows a
25
-------
1800
1500 1200 0900
PST 7 NOV 75
0600
Figure 9. This fall day shows the high values of NOj created by morning
traffic which disappears in midday when the radiation inversion
breaks.
a too
1800
1500
PST 17 DEC 75
1200
0900
Figure 10. Very high NOX/NO values on a December morning* Almost all
the NOX was NO. The spike at 0800, caused by a nearby tractor,
led to an NO value which exceeded the NOX.
26
-------
0.5,
Q.
Q.
0.4
0.2
O.I
NO AND NOX
0200 O4OO O6OO 0800 1000 1200 I4OO I6OO
PACIFIC STANDARD TIME, 15 JULY 1977
1800 2000 2200 24OO
Figure 11. The NOX/NO traces after installation of the integrating bottle.
Both traces are much smoother than in Fig. 9 and 10. The per-
sistent overnight NOX must represent previous days pollution
whereas the NO (note that it parallels the NO^) represents new
infusions of combustion gas.
spike of >0.9 ppm at 0745 which is attributed to a nearby farm tractor (the
sampling site is in a "weather station" in the middle of an experimental
agricultural field). The rarity of these events suggests that these local
sources are not a serious interference with the experimental plan. The fact
that this one NO reading exceeded the NOX would lead to a negative N0£ +
PAN + NO - concentration. It points up the hazard involved in subtraction
methods involving consecutive samples (such as the conventional THC - CH^
= NMHC). The fraction of the NOX which is NO gives an independent assess-
ment of the degree of reaction.
OXIDANT AND OZONE
Two instruments are in operation for measurement of these two closely
27
-------
related quantitites. Oxidant is measured by the potassium iodide procedure
using a coulometric analyzer (Mast). This instrument has been in operation
for many years. Formerly, the manual KI calibration procedure of the
California Air Resource Board was used. Since this was found to give high
readings the calibration procedure has been changed to conform to the UV
photometric standard established at the El Monte laboratory of the Air
Resources Board.
Ozone was measured by a ultraviolet analyzer (Dasibi) which is also
coordinated with the photometric ozone standards. Typical records are shown
in Figures 12 and 13. These records correspond to the NOX traces of Figures
9 and 11. It appears now that the ultraviolet photometer can come close to
qualifying as a primary standard (R. J. Paur, NYC ACS meeting, 1976) since
the ultraviolet absorption spectrum is known with high accuracy and the
other important variables are readily ascertainable (pressure, temperature,
path-length).
0900
1800
PST 7 NOV 75
Figure 12. Typical ozone and ultraviolet radiation record early fall.
Compare NOX in Figure 9.
28
-------
03 CONCENTRATION AND UV IRRADIATION
O20O O4OO
O600 080O IOOO I2OO 1400 I6OO I8OO
PACIFIC STANDARD TIME, 15 JULY 1977
2000 220O
Figure 13* Summer record of ozone and ultraviolet*
FAN
AD. automatated PAN chromatograph (electron capture) operating on a
15-minute cycle has been in operation for many years. This was maintained
in operation and calibration even though it did not play an important role
in the present program.
LIGHT INTENSITY
An ultraviolet radiometer (Eppley Laboratories Model TUVR) was in-
stalled on the roof of the weather station to monitor total ultraviolet
(295-385 nanometers, approximately). This instrument suffered a sudden
unexplained loss of output signal twice during the program. Typical
records are shown in Figures 12 and 13.
29
-------
DATA REDUCTION
These five monitoring instruments were operated around the clock in
the UCR weather station. To summarize the measurements which were made on
a continuous or automatic basis:
1. Hydrocarbons by gas chromatography with flame ionization. Direct
injection measurement of methane, ethane, ethene, acetylene and
C3+ hydrocarbons (by backflush).
2. Nitrogen Oxides - By ozone chemiluminescence. This measures NO
and NOx with the latter being take as equal total oxidized nitro-
gen.
3. Oxidant - By coulometric KI method.
4. Ozone - By UV absorption.
5. UV Intensity - By recording of UV meter.
The analytical data were recorded on strip charts since this was regarded as
a pilot program automatic reduction of the chromatographic output would be
difficult. Peak heights and deflections were read from the strip charts and
entered into punch cards for machine handling. Sensitivity factors were
also entered via punch cards. To make all data comparable with the 15
minute sampling interval of the chromatographs the other measurements were
averaged over these same intervals. Five hydrocarbon measurements plus five
other variables adds to 40 points per hour or 960 per day. Only machine
handling makes this manageable. It facilitated grouping the data points
according to ethene/acetylene ratio (indicative of degree of reaction) and
other variables.
30
-------
SECTION 5
RESULTS
Each Instrument of course suffered its share of downtime so the major
effort at data reduction was directed toward those days during which the
most data, especially for hydrocarbon and nitrogen oxides, were available.
Eventually the data for 61 days were reduced to machine readable form. If
a11 instruments had produced full sets of data 61 x 960 = 58,560 concentra-
tions would have been recorded. Even the incomplete set which was obtained
represents a large manual effort. The strip chart values were read by hand
first then into punch cards. This deck of cards constitutes the useful data
output of the project. The contents of the cards were printed but it would
clearly be hopeless to derive any useful conclusions by visual examination
of data in this form.
The number of different manipulations possible for this data set
is limited only by imagination. The major effort was directed toward
tabulation of "conditional joint distributions." With ten variables
(plus time) on the cards 45 different pairings are possible. Some of these
would be meaningless so effort was concentrated on conditional distri-
butions of the more interesting combinations. Photochemical smog con-
ditions can be selected by the condition 03 > 60 ug/m3. The various
conditional joint distributions are shown in Tables 5 to 15.
COMMENTS ON TABLES
As stated earlier ethene and acetylene were added to the 03"*" (back-
31
-------
flush peak) as a measure of the significant hydrocarbon. Methane was
omitted for the traditional reasons: (1) it is present in amounts large
enough to dominate the hydrocarbon, much of it (1.4 ppm = 887 ug/m^) as
worldwide background. (2) it is quite low in reactivity. Ethane was
also omitted because it is attributed in large part to natural gas. It's
inclusion might degrade any correlations dependent on auto emissions
without making a large difference. It is also of low reactivity. Since
the back flush peak also probably includes oxygenates a fitting heading
might be nonmethane ethane organic (NMEO). The first six tables show
joint distributions of these parameters with various others and with
various conditions.
Table 5. This set (NMEO vs NOx) should give a narrow band of
entries sloping downward to the right if the emissions were always in the
same ratio and if atmospheric reaction affected them equally. Part a which
includes data from all 61 days shows a broader spread than anticipated.
Some of this spread might arise from failure to measure NMEO and NOX on
the same air sample. Failure to coordinate the time scales precisely would
cause this if the concentrations are fluctuating rapidly. This was the
reason for inserting the integrator bottle into the sampling line on April
19, 1977. The distribution after that date (Table Ib) was somewhat narrower
but still fairly broad. Tables Ic and Id compare these same joint distribu-
tions for reacted and unreacted samples. The ratio of NMHC to NOX is
larger in the reacted samples as though more NOX than hydrocarbon were
lost by reaction. Tables le and If show this same distribution for morning
hours and evening hours. These show similar patterns but the evening
hours appear to have more high values.
32
-------
Table 6. This shows the NMEO In joint distribution with NO. As
expected this shows many NO values below the minimum of 50 ug/nH corres-
ponding to reacted samples.
Table 7. This joint distribution of NMEO with ozone shows an
interesting bimodal plot. The low 03 values correspond to unreacted
mixtures whereas the low hydrocarbon values represent photochemical smog.
Some high ozone values (>400 ug/m^; 0.21 ppm) were recorded for hydro-
carbon values under 500 ug/m^ (=0.78 ppm).
Table 8. The joint distribution of non-methane-ethane-organic with
acetylene. This interesting set of tables makes use of the relative
inertness of acetylene and its unique association with auto exhaust.
All three of these distributions show a relatively narrow spread. This
clearly Illustrates the strong dependence of NMEO on engine exhaust.
The few outliers with high NMEO at low acetylene (<10 ug/m^) may be due to
unusual discharges from other sources (i.e., pesticide application on the
surrounding agricultural fields). The effect of photochemical reaction can
be seen by comparing 8b (smog, 03 > 160 ug/m^) with 8c (unreacted emissions,
NO > 60 ug/m^)• Loss of NMEO relative to acetylene is not dlscernable
in these data. Since acetylene is of low reactivity the average NMEO
must produce other organics with little loss of effect on the flame ioniza-
tion detector* Based on these three tables it would be hard to justify
any "back extrapolation" to a higher hydrocarbon value in the unreacted
state.
Table 9. The joint distribution of NMEO with ethane shows a fair
correlation even though the former is derived from auto exhaust and the
latter from natural gas. There is no definite bias for either morning
33
-------
or evening.
Table 10. These joint distributions with methane show larger spreads
because of the background methane concentrations.
Table 11. These joint distributions of acetylene with ethene reveal
the higher reactivity of the former, lid shows the good correlation in
the unreacted samples (NO > 60 ug/m3) with the weights of the two hydro-
carbons being about equal (prior work indicated a weight ratio of 0.9).
Table lie shows the reacted (ozone > 160 ug/m3) samples; the lowered
relative amount of ethene caused by reaction (e.g. in the unreacted samples
the maximum frequency (62) occurs in the 30-40 by 30-40 bracket (Table lid)
but the maximum frequency (21) for this acetylene level occurs in the 20-30
ug/m3 ethene bracket for reacted samples.) If only higher ozone levels were
considered, e.g., >300 ug/m3, there would be fewer data but a larger deple-
tion of ethene with respect to acetylene would be seen.
Table 12. These joint distributions of acetylene and methane again
show how a degree of correlation is produced by common trapping of hydrocar-
bons from different sources. The spreads are so broad that no trends are
evident.
Table 13. The joint distribution of ethane and methane do not show
as narrow a spread as expected for hydrocarbons with a common origin.
Perhaps there is variability with time in the ethane content of natural
gas.
Table 14. This joint distribution of ozone and oxidant shows the
expected good correlation. Oxidant values seem to be systematically
low; they were corrected for neither positive (N02, PAN) nor negative
(S02) interferences.
34
-------
Table 15. This joint distribution of ozone with NOX at NMEO above 160
ug/m3 shows a bimodal distribution between the two variables. This reflects
the contrast between reacted and unreacted samples. It may be noted that
t
3469 out of 5092 recorded values were above 160 ug NMEO/m3.
Preparation of this type of data analysis inevitably invites con-
sideration of alternative modes of analysis which could be done and which
might be revealing. Conditional linear regressions would be one tempting
procedure. For example, ethene regressed with acetylene at various oxidant
levels and for high values of NO/NOX would reveal the selective loss of
the more reactive hydrocarbon. Regression of NMEO with acetylene with the
same conditions would explore the extent to which this is a "net" loss of
higher molecular weight organic due to reaction.
35
-------
5a. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS (ETHENE PLUS ACETYLENE
PLUS BACK FLUSH PEAK) AND NOX [NO + NO* + PAN + NITRATES (?)] WEIGfiT AS N02.
a. ALL REDUCED DATA
(C2H4, C2H2, C3+) UG/M3 ****
NUX UG/P3
0- <
50- <
100- <
150- <
200- <
250- <
300- <
3i>0- <
400- <
450- <
500- <
550- <
600- <
650- <
700- <
750- <
800- <
850- <
900- <
950- <
TOTAL
50
100
150
200
250.
300
350
400 .
450
500
550
600
650
700
750
..,800 .._,,
850
900
950
1000 -
0 -
413
1114
672
28d
154
68
23
16
4
I
0
0
1
0
0
_~,.-Q.
0
0
0
0
2754
500 - 1000 - 1JOO - 20CC - 25CO - 3GOO - 3500 - 4000 - 45uO - 5000 TOTAL
0
60
229
_. 268
194
116
81
35
31
14
11
4
3
2
0
I
6
0
0
0
1049
0
4
26
38
36
40
32
19
23
15
23
11
2
1
4
1
0
0
0
0
275
0
0
3
23
29
34
20
11
6
8
3
3
1
2
3
0
1
0
0
0
147
0
0
0
10
16
17
22
11
12
2
4
3
2
1
1
0.
1
0
0
0
102
• o
0
0-
1
1
2
1
4
4
. 4
2
4
3
2
1
0
0
2
3
0
34
0
0
0
2
0
0
1
0
0
1
0 •
1
0
0
2
- 0.
0
0
0
0
7
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
- . 0
0
0
0
0
1
0
0
0
0
0
0
0
J
0
J
J
J
0
0
0
. 0
1
0
0
0
1
0
0
0
6
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
413
1176
93 0
63C
430
277
UO
V6
6G
45
43
27
U
8
11
. . 2
3
2
3
0
4370
-------
5b. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS (ETHENE PLUS ACETYLENE
PLUS BACK FLUSH PEAK) AND NOx [NO + NO* + PAN -I- NITRATES (?)] WEIGHT AS N02-
b. AFTER INSTALLATION OF INTEGRATOR BOTTLE
u>
NOX UG/M3 0 - $00
0- < 50 " 72
50- < 100 346
100- < 150 150
150- < 200 34
200- < 250 16
250- < 300 ,, 13
300- < 350 «. $'•-. 2
350- < 400 0
400- <
450- <
500- <
530- <
600- <
650- <
700- <
750- <
800- <
850-
-------
U)
00
5c. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS (ETH.ENE PLUS ACETYLENE
PLUS BACK FLUSH PEAK) AND NOX [NO + NO* + PAN + NITRATES. (?)] WEIGHT AS N02«
c. FOR OZONE EXCEEDING THE STANDARD
(C2H4. C2H2t C3+) UG/M3 **** 0^ >= 160 UG/M3
NOX UG/M3
0- <
50- <
100- <
150- <
200- <
250- <
300- <
350- <
400- <
450- <
500- <
550- <
600- <
650- <
700- <
750- <
800- <
850- <
900- <
950- <
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
0 - 500
49
239
62
3
• 1
0
0
0
0
0
0
0
0
0
0
_ 0
0
0
0
0
- 1000 - 1^00 - 2000 - 2500
0
22
54
23
4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
7
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
8
3
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
7
6
2
2
0
1
0
0
0
, o
0
, 0
0
0
0
0
cr
- 3000
0
0
0
0
0
0
0
0
0
0
0
'to .
'0
0
0
0
0
0-
0
0
- 3500 > 4000
.0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
- 45uO - 5000
0
0
0
0
0
0
V 0
J
0
u
0
0
0
0
0
0
0
J
0
J
0
0
o-
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
TuTAL
49
i6 1
121
53
15
2
4
0
1
0
0
0
0
u
0
0
0
0
0
0
TOTAL 359 103 11 15 18 0 0 0 0 0 506
-------
I
u>
5d. JOIOT DISTRIBUTION OF RON METHAHE/ETHANE ORGAHICS (ETHENE PtUS ACETYLENE
PLUS BACK FLUSH PEAK) AND NO* [NO + NOjj + PAN + NITRATES (?)] WEIGHT AS N02«
d. FOR UNREACTED AIR (HIGH NITRIC OXIDE)
_
IC2H4i C2H2t C3+) UC/M3 **** NO >> 60 'UG/M3
NOX UG/M3 0 — 500 -, 1000 - 1500 - 2000 - 2500 - 3000 - 3500
0- <
50- <
100- <
150- <
200- <
250- <
300- <
350- <
400- <
450- <
500- <
550- <
600- <
650- <
700- <
750- <
800- <
850- <
900- <
950- <
TOTAL
50
100
150
200
250
300
350
400
450
500
550
600,
650
700
750*
800
'850
900
450
1000
0
1
14
92
"~'125
63
22
15
4
........ 1
0
0
• 1
0 '
0
o
fl •--.-;
0
0
0
338
0'
0
6
. 33
.97
90
76
34
31
14
11
4
3
2
0
i
0
0
0
0
402
0
0
0
2
9
21
23
.19
23
14
23
11
2
1
4
_ I
0
0
0
0
153
0
0
0
0
0
17
9
11
6
8
3
3
1
2
3
0
I
0
0
0
64
0
0
0
0
1
6
5
7
4
1
4
3
2
1
1
0
1
0
0
0
36 .
0
0
0
0
1
2
0
0
3
4
2
4
3
2
1
0
0
2
3
0
27
0
0
0
1
0
0
1
0'
0
1 ,
0
1
u
0
2
0
0
0
0
0
6
- 4000 - 4500 - 5000 TOTAL
0
0
0
0
- 0
0
0
0
0
0
0
1
•0
0
0
0
0
0
0
0
i'
v)
0
0
u
u
0
0
0
u
u
v)
g
U
0
0
0
1
0
u
0
• 1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
. 0
0
0
0
1
20
Ub
2J3
199
136
66
71
43
43
27
12
a
ii
2
3
2
3
0
1028
-------
5e. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS (ETHENE PLUS ACETYLENE
PLUS BACK FLUSH PEAK) AND NOx [NO + NOX + PAN + NITRATES (?)] WEIGHT AS N02«
e. FOR MORNING HOURS
IC2H4, C2H2f C3+) UG/M3 ****
NO* UG/M3 0 - 500 - 1000 - 1500
0- <
50- <
100- <
150- <
200- <
25U- <
300- <
350- <
400- <
4!>0- <
500- <
550- <
600- <
650- <
700- <
750- <
800- <
850- <
900- <
950- <
TOTAL
50
100
150
200
250
300
'350
400
450
500
550
600
650
700
750
800
850
900 .
950
1000
16
76
78
50
42
23
8
6
1
1 .._
0
0
1
0
0
.. o
0
0
0
0
302
0
1
13
39
23
17
17
9
7
4
0
1
1
1.
0
0
0
0
0
0
133
0
0 ,
6
5
3
2
5
1
4
2
3
3
0
1
2
0
0
0
0
0
37
- 2000 •
0
0
0
1
0
1
4
0
0
0
0
0
0
0
0
0
0
0
0
0
6
- 2500 -
o •
0
0
0
0
• o
2
0
1
0
0
0
0
0
0
0
0
0
0
0
3
0600 - C900 HST
• 3000 - 3500 - 4000 - 4500 -
0
0
0
0
1
1
0
0
0
0
0
u
0
0
0
0'
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
1
o
0
J
0
0
0
0
0
0
o
0
0
0
0
0
0
0
0
0
J
0
0
0
0
u
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
- 50UO
TOTAL
lo
77
97
9b
o9
44
36
16
13
7
3
5
2
2
2
0
0
0
c
G
-------
5f. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS (ETHENE PLUS ACETYLENE
PLUS BACK FLUSH PEAK) AND NOX [NO + NOx + PAN + NITRATES (?)] WEIGHT AS N02-
f. FOR EVENING HOURS
NOX UG/M3
0- <
50- <
100- <
150- <
200- <
250- <
300- <
350- <
400- <
450- <
500- <
550- <
600- <
650- <
700- <
750- <
800- <
850- <
900- <
950- <
TOTAL
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800.
850
900
950
1000
0 - 500
35
127
131
70
32
. 17
10
6
0
„.. . o
0
0
0
0
0
o.
0
0
0
0
428
- 1000 - .
0
4
46
61
27
17
20
9
11
.5
3
2
1
1
0
1
0
0
0 '
0
208
0
1
2
8
6
4
6
7
4
7
8
3
2
0
2
1
0
0
0
0
61
-------
TABLE 6,
NS
JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS (ETHENE PLUS ACETYLENE
PLUS BACK FLUSH PEAK) AND NO (WEIGHT AS NO).
(C2H4, C2H2, C3+) UG/M3 ****
500 - 1000 - liiOO - 2000 - 2500 - 3000 - 3500
- 4000 - 450J - 50CU TOTAL
0- <
50- <
100- <
150- <
2'00- <
250- <
300- <
350- <
400- <
450- <
500- <
550- <
600- <
650- <
700- <
750- <
800- <
650- <
900- <
9 SO'- <
TOTAL
SO
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
2340
279
91
25
7
2
0
0
0
0
0
• o
0
0
0
, 0
0
0
0
0
2744
576
236
129 '
56
28
20
7
2
0
0
0
0
0
0
0
0
0 -
0
0
0
1054
112
42
38
29
29
• 13
7
4
2'
0
0
U
0
0
0
0
0
0
0
0
276
77
23
19
6
7
9
4
0
0
0
0
0
0
0
0
0
0
0
0
0
147
62
17
7
5
•t
3
2
0
0
' 2
0
0
0
1
0
0
0
0
0
0
103
5
6
8
5
1
4
3
• 0
3
0 .
0
0
0
0
0
0
0
0
u
0
35
1
1
1
2
0
2
0
0
0
0
I)
0
• 0
- 0
0
0
0
0
0
0
7
0
0
0
0
0
1
0
0
0
0
0
1
0
0
0
• o
u
0
• 0
0
2
0
0
0
0
J
0
u
1
0
J
0
0
0
0
0
0
0
0
0
J
1
0
o
u
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3173
604
293
130
76
54
23
7
5
2
U
1
0
1
0
0
0
0
u
0
4369
TABLE 7. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS WITH OZONE.
(C2H4. C2H2, C3+)
03 U6/N3
0- < 50
_• 50- ^ 100
iOO- <
150- <
200- <_
250- <
300- <
350- <
400- <
450- <
TOTAL
150
200
250
300
350
400
450
500
0 - 500 -
1658 821
440 82
•269
121
. 116
77
30
25
11
0
2747
34
31
29
19
13
10
4
X
1044
UG/M3 ****
1000 - 1500 - 2000 - 2500 - 3000 - 3500 - 4000 - 4500 - 5000 TOTAL
210 98 48 24 6 2 10 2868
40 27 28 11 . 1 0 0 0 629
14
4
1
3
. 0
0
3
. 0
275
• 7
3
V
3
2
2
0
•; -. 0
_146
7
5
8
3
0
• 1
\
v. 0
IQl
0
0
0
0
0
0
0
0
.35
0
0
0
0
• o •
0
0
0
7
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
.„ . 1 -
0
0
0
0
0
0
0
0
0
331
164
15d
105
45
36
19
1
4358
-------
*-
U
TABLE 8a. JOINT DISTRIBUTION OF NON METHANE/ETHAKE ORGAKICB WITH ACETYLENE
a. ALL REDUCED DATA
(C2H4* C2H2» C3+» UG/M3 ****
H2 UC/N3
0- < 10
10- < 20
20- < 30
30- <.. .40
40- < 50
50- < 60
60- < . 70
70- < ' 80
80- < 90
90- < 100
TOTAL
0 -
2611
148
0
.. 0
0
0
0
0
0
0
2759
500 - 1000
178
804
72
... 1
0
0
1
0
0
..... . 0
1056
- lioo
1
50
193
30
3
0
0
0
0
0
277
- 200C
0
2
44
93
8
0
0
0
0
0
147
- 2500
1
0
2
72
21
6
0
1
0
0
103
- 3000 -
0
2
1
11
15
5
1
0
0
0
35
3500 -
2
0
1
1
0
1
2
0
0
0
7
4000
0
0
0
0
1
0
0
1
0
U
2
J
Q
^
j
i)
1
0
0
J
0
1
>0 - 5000
0
U
0
0
0
0
0
.0
U
. 0
0
TOTAL
2793
1006
313
20ti
48
13
4
2
0
0
43d7
TABLE 8b. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS WITH ACETYLENE
b. OZONE ABOVE STANDARD
H2 UG/M3
0- <
10- <
20- <
30- <
40- <
50- <
60- <
70- <
80- <
90- <
TOTAL
10
,20. ._
30
40
50
60
70
....8Q_._
90
100
0 - $00
341
18™. , .
0
0
0 ...
0
0
__ 0. . .,..
0
0
,.. 3S9
- 1000
32
66 . .
5
0
0
0
0
0 .
0
0
103
—
0
2
8
1
0
0
0
: o
0
0
11
(C2H4t C2H2t C3+) UG/M3 **** 03 >» 160 UG/M3
1500 - 2000 - 2500 - 3000 - 3500 - 4UOU - 4500 - 5000
0
0
6
7
2
0
0
0
0
0
15
0
0
0
18
0
0
0
0
0
0
18
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U
0
0
0
0
0
0
0
0
0
0
0
0
0
0
J
0
J
J
a
J
0
0
0
0
0
0
0
0
U
0
0
0
TOTAL
373
66
19
2t>
2
0
U
0
Q
0
506
-------
TABLE 8c. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS WITH ACETYLENE
c. UNREACTED AIR, NO ABOVE 60 ug/m3 (0.05 ppm).
(C2M4t C2H2, C3+) UG/M3 **** NO > 60 UG/M3
H2 UG/M3
0- <
10- <
20- <
30- <
40- <
50-
-------
TABLE 9abc. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS WITH ETHANE
a. ALL REDUCED DATA, b. MORNING, c* EVENTING.
(C2H4» C2H2» C3+) UG/M3 ****
H6 UC/M3
0- < 10
10- < 20
20- < 30
30- < 40.
40- < 50
50- < 60
60- <. ..70 _
70- < 80
80- < 90
90- < 1QQ.
TOTAL
0 -
2151
600
5
0
0
0
0
0
0
^ o
2756
500 - 1000
52
727
254
19
1
1
. . ... 0
0
0
Q,
1054
- I5v)0
0
49
98
112
17
1
0
0
0
0
277
- 2000
0
2
15
2B
63
36
2
0
1
0
147
- 2*CO
0
1
4
4
19
39
34
2
. 0
o
103
. 3000
0
1
1
0
4
6
22
0
1
o
35
- -3500
0
2
0
1
0
1
3
0
0
o
7
- 40UO
0
0
1
0
J
1
0
0
0
0
2
- 4500
0
U
0
0
0
0
1
0
0
J
1
- 5uOO
0
0
0
0
0
0
0
0
0
o
.0
TOTAL
22u3
13«2
378
lot
104
b5
62
2
2
o
43U2
C2H6 UG/M3
Ul
0- <
10- <
20- <
30- <
40- <
50- <
60- <
70- < 80.
80- < 90
90- < 100
TOTAL
10
.20
30
40
50
60
70
0 - 500 -
219
,_ Bl.._
2
0
.... 0..
0
0
o_
0
0
302
00 -
0
0
0
0
0
0
0
J
0
0
0
5000
0
0
0
0
0
0
0 '
0
0
0
0
TOTAL
229
171
ol
17
10
1
0
0
0
c
4dS
H6 UG/H3
0- <
10- <
20- <
30- <
40- <
50- <
60- <
70- <
80- <
90- <
TOTAL
10
20
30
40
50
... 60
70
80
90
100
... Q_r.
354
73
i
. 0
0
._ 0
0
0
0
0
428
500 - 1000
11
164
29
4
' 0
0
0
0
0
0
208
- .1500
0
8
32
18
3
. 0
0
0
0
0
61
- 200C
0
1
8
4
29
16 .
1
0
1
0
60
- 2500
0
0
2
2
8
19 .
16
1
0
0
48
- 3000 -
0
0
0
0
2
4
17
0
0
0
23
3500 -
0
0
0
1
0
1
2
0
0
0
4
4000
0
0
0
0
0
0
0
0
0
0
0
- 4500 -
0
0
0
o
0
0
1
0
0
0
1
5000
0
0
0
0
0
0
0
0
0
0
0
TOTAL
305
246
72
29
42
40
37
1
1
0
833
-------
TABLE lOab. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGANICS WITH METHANE
a. ALL REDUCED DATA, b. MORNING.
(C2H4, C2H2f C3+) UG/M3 ****
CH4 UG/M3 0 - 500 - 1000 - laOO - 2000 - 2500 - JOOO - 3500 - 4000 - 4500 -
7UO- <
800- <
900- <
1000- <
1100- <
1200- <
1300- <
1400- <
1500- <
1600- <
1700- <
1600- <
1900- <
TOTAL
800
900
1000
1100
1200'
1300
1400
1500
1600
1700
1800
1900
2000
CH4 UG/M3
700- <
600- <
900- <
1000- <
1100- <
1200- <
1300- <
1400- <
1500- <
1600- <
1700- <
1800- <
1900- <
TOTAL
800
. 900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
224
539
480
1 254
632
216
56
17
10
2
4
1
1
2436
0 -
15
49
67
20
70
45
7
2
1
1
0
0
0
277
0
2
83
208
145
176
144
65
30
8
1
2
3
867
500 - 1000
0
0
6
15
25
30
14
8
6
1
0
0
0
105
0
0
0
3
5
19
56
52
34
27
8
2
3
209
-
0
0
0
2
1
3
6
2
3
9
1
0
0
27
0
0
0
0
0
0
3
20
23
26
10
8
4
94
IC2H4, C2H2t
1500 - 2000 -
0
0
0
0
0
0
0
0
0
0
0
4
1
5
0
0
0
1
0
0
2
5
16
10
6
11
4
55
C3+)
2500
0
0
•o
0
0
0
1
0
0
0
0
2
1
4
0
0
0
0
0
0
• 1
0
1
10
1
3
5
21
UG/M3
- 3000
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
0
1
0
1
0
0
1
1
0
2
0
6
0
0 \
Q
0
0
0
0
0
0
0
0
0
0
0
**** 0600 - 0900
—
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3500 - 4000 -
0
0
0
0
0
0
0
0
0
0
0
0
0
0
J
0
0
0
o
0
u
0
0
0
0
0
1
1
PST
45OO
0
0
0
0
u
0
J
0
0
0
0
J
0
0
0
0
0
0
0
0
0
0
0
0
0
0
J
J
- 5000
0
0
0
0
0
0
0
0
0
0
• 0
0
0
0
TCTAL
2<:4
467
762
412
2o2
. 159
115
84
30
29
36o9
TOTAL
15
49
73
37
76
26
10
11
1
7
2
419
-------
TABLE lOcd. JOINT DISTRIBUTION OF NON METHANE/ETHANE ORGAN1CS WITH METHANE
c. EVENINGS, d. OZONE ABOVE STANDARD.
CH4 UG/H3
700- <
800- <
900- <
1000- <
1100- <
1200- <
1300- <
.1400- <
1500- <
1600- <
1700- <
1800- <
1900- <
TOTAL
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
CH4 U6/M3
700- <
<>00- <
900- <
1000- <
1100- <
1200- <
1300- <
1400- <
1500- <
1600- <
1700- <
1800- <
1900- <
TOTAL
800
900
1000
1100
1200
1300
1400
1500
1600
17CO
1800
1900
aooo
•
0 - 500
21
75
88
50
106
21
1
0
0
0
1
0
0
363
0 - , 500
52
127
104
37
. 6
5
3
6
2
1
0
0
0
343
- iooo
0
2
30
61
25
29
31
6
1
0
0
0
0
165
- 1000
0
0
13
27
5
8
2
6
8
2
0
0
0
71
-
0
0
.. 0
. 1
1
1
19
13
8
4
I
1
0
49
-
0
0
0
0
.... o
0
0
1
2
1
0
0
0
4
IC2H4, C2H2i
1500 - 2000 -
J
0
0
0
0
0
t
15
8
9
6
0
2
41
(C2H4, C2H2t
1500 - 2000 -
0
0
0
0
0
0
q
3'
2
0
0
0
0
5
C3+J
2500
U
U
0
0
0
0
0
3
8
5
3
4
0
23
C3+1
2500
0
0
0
-0
0
0
0
0
3
4
0
0
0
7
UG/M3
- 3000
J
0
0
0
0
0
0
0
0
8
1
2
3
14
UG/M3
- 3000
0
0
0
0
0
0
0
0
0
0
0
0
0
• o
**** 2000 - 2400 P&T
- 3500 -
0
0
0
0
0
0
0
0
1
1
0
2
0
4
**** 03
- 3500 -
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4000
0
'0
0
0
0
0
0
0
0
U
0
0
0
0
>» 160
4000
0
0
0
Q
0
0
0
0
0
0
0
0
0
0
- 4500 -
J
J
0
0
0
ll
U
U
0
0
U
0
1
1
UG/M3
— 41>0l
J
0
0
a
u
o
0
0
0
J
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
) - :
0
0
0
U
0
0
J
0
0
0
0
0
0
0
- 5JOO
TOTAL
tl
77
118
1U
52
37
26
27
12
9
6
6tiO
- 5000 TOTAL
127
117
64
11
5
16
17
8
0
0
0
430
-------
TABLE llab. JOINT DISTRIBUTION OF ACETYLENE AND ETHENE
a. ALL REDUCED DATA, b. DATA WITH INTEGRATOR BOTTLE,
C2H2 UG/M3
C2H4 UG/M3
0- <
10- <
20- <
30- <
40- <
SO- <
60- <
70- <
80- <
90- <..
TOTAL
10
20
30
40
50
60
70
80
90
100
0 -
2U71
126
0
. : o
0
0
0
0
0
._ 4 0
2997
10 -
141
830
46
0
0
0
0
0
0
0
1017
#*
20 -
1
74
205
35
0
0
0
0
0
0
315
30 -
0
2
• 88
97
21
0
0
0
0
0
208
40 -
0
1
1
la
is
11
0.
, 0
" 0
0
49
50 -
0
0
0
1
. 5
6
2
0
0
0
14
60 -
0
0
0
0
0
0
2
2
0
0
4
70 -
0
0
0
0
0
0
1
1
0
0
2
80 -
v>
J
0
0
d
0
0
0
0
0
J
90 -
C2H2 UG/M3 '** AFTER 4/19/77
100
0
u
0
0
0
0
0.
0
0
0
0
TOTAL
3013
1C33
34u
lt>l
44
17
5
3
0
0
4606
00
C2H4 UG/M3
0- <
10- <
20- <
30- <
40- <
50- <
60- <
70- <..
80- <
90- <
TOTAL
10
.20 ...
30
40
50
"60
70
80
90
100
0. -
727
... 21
0
. 0
0
0
0
0
0
0
....748
10 -
40
... 205
0
0
0.
0
0
.._ o
0
0
245
20 -
0
3
0
0
0
0
0
„ o
0
0
3
30 -
0
0
0
0
0
0
0
0
0
0
0
40 -
0
0
0
0
0
0
0
0
0
0
0
50 -
0
0
0
0
. 0
0
0
0
0
0
0
60 -
0
0
0
0
0
0
0
0
0
0
u
70 -
0
0
0
0
0
0
0
. 0
0
0
0
80 -
0
0
0
w
J
0
0
u
0
0
J
90 - 10U
0
0
0
0
0
0
0
0
0
0
0
TOTAL
767
229
G
0
C
0
.0
0
0
0
996
-------
TABLE lied.
JOINT DISTRIBUTION OF ACETYLENE AND ETHENE
c. DATA FOR OZONE ABOVE STANDARD, d. DATA FOR HIGH NO (UNREACTED)
C2HVUG/M3 0
0- < 10
10- < 20
20- < 30
30- < 40
40- < 50
50- < 60
60- < 70
70- < 80
BO- < 90
. 90- < 100 t
TOTAL
C2H4 UG/M3 0
0- < 10
10- <. 20......
20- < 30
30- < 40
40- < 50
50- < 60
60- < 70
70- < 80
80- < '90*~ •
90- < 100
TOTAL
C2H2
—
387
2
0
0
0
0
0
0
0
0
389"
C2H2
-
239
.84..,
0
0
0
0
0
0
0
0
323
UG/M3
10 -
60
27
0
0
0
0
0
0
0
0
87
UG/M3
10 -
5
_ 361
43
0
0
0
0
0
0
0
409
** 03 >= 160 UG/M3
20 - 30 - 40 -
50 -
60 -
70 -
80 -
1
18
0
0
0
0
0
0
0
0
19
0
2
21
3
0
0
0
0
0
0
26
0
9
142
28
0
0
0
0
0
0
179
0
0
16
62
20
0
0
0
0
0
98
0
1
0
1
0
0
0
0
0
0
2
** NO > 60 UG/M3
20 - 30 - 40 -
0
0
1
6
17
11
0
0
0
0
35
0
0
0
0
0
0
0
0
0
0
0
50 -
0
0
0
0
1
5
2
0
0
0
8
0
0
0
0
0
0
0
0
0
0
0
60 -
0
0
0
0
0
0
2
2
0
0
4
0
0
0
0
0
0
0
0
0
0
0
70 -
0
0
0
0
0
0
1
1
0
0
2
J
0
o
o
i)
0
0
u
0
0
0
80 -
0
0
0
d
J
u
0
0
0
0
0
0
0
0
0
0
0
0
0
0
90 -
1UO IGTAL
44o
50
21
4
0
0
0
0
u
0
523
1JO TOTAL
0
0
0
0
0
0
0
0
0
0
0
202
*6
3U
16
5
3
0
0
1058
-------
TABLE 12ab.
JOINT DISTRIBUTION OF ACETYLENE AND METHANE
a. ALL REDUCED DATA, b. MORNING.
C2H2 UG/M3
CH4 UG/M3
700- < 800
800- < 900
900- < 1000
1000- < 1100
1100- < 1200
1200- < 1300
1300- < 1400
1400- < 1500
1500- < 1600
1600- < 1700
1700- < 1800
iaoo- <. 1900
1900- < 2000
TUTAL
In
O
CH4 UG/M3
700- < 800
600- < 900
900- < 1000
1000- < liO'O
1100- < 1200
1200- < 1300'
1300- .< 1400
1400^- < 1500
1S>00- < 1600
1600- < 1700
1700- < 1800
iaoo- < 1900
1900- < 2000
TOTAL
0 -. 10
263
5bl
533
401
642
205
46
10
8
2
4
' 1
1
2697
-
0
1
46
146
168
182
153
74
32
6
2
3
a 16
C2H2 UG/M3
0-- 10
17 -
55
69
33
,_..>_68
j 4g ~
8
0
1
1
0 .
0
0
300
-
0
0
4
17
34
27
10
8
8
1
0
1
0
110
**
20 - 30
0
0
0
1
1
30
59
49
38
..... 33
9
5
4
229
** 0600
20 - 30
0
0
0
0
0
5
6
3
0
8
1
1
0
24
40 -
U
0
0
0
0
2
5
24
35
30
14
14
8
132
- 0900 PST
40 -
0
0
0
0
0
1
2
1
1
1
0
5
1
12
0
0
0
0
0
1
1
2
3
10..
1
3
4
25
0
0
0
0
0
1
1
0
0
0
0
0
1
3
50 -
0
0
0
0
0
0
0
0
0
1
1
3
1
6
50 -
0
0
0
0
0
0
0
0
0
0
0
0
0
0
\
•I,
60 A,
'IP
''1
ol'ii
07
0 !
0
0
0
0
.. o
1
. 1
0
2
60 -
0
0
0
0
0
0
0
0
0
0
0
0
0
0
70 -
0
0
'» °
\ o
m 0
'^f 0
'• -!)• 1 •
T f
>' -I, 0
0
. ::, 0
''0
0
0
1
70 -
0
0
0
0
0
0
1
0
0
0
0
0
0
1
ao -
0
0
^
0
a
0
J
0
0
0
0
0
0
0
80 -
J
0
0
0
0
0
' 0
0
0
'. *^
0
0
'0
0
9U - 100
0
0
0
0
0
0
0
0
o-
0
0
0
0
0
90 - 1UO
0
0
0
0
0
0
0
0
0
0
0
0
0
0
TOTAL
263
5«2
579
^46
an
42U
26li
159
116
as
30
29
21
39ua
TOTAL
17
55
73
50
.102
82
2ti
12
lH
11
1
7
2
450
-------
TABLE 12cd.
JOINT DISTRIBUTION OF ACETYLENE AND METHANE
c. EVENING, d. UNREACTED AIR NO >60 ug/m3.
C2H2 UG/M3
CH4 UG/H3
700- <
800- <
900- <
1000- <
1100- <
1200- <
1300- <
1400- <
1500- <
1600- <
1700- <
1800- <
1900- <
TOTAL
800
900
1000
1100
1200
I300r_
1400
1500
1600
1700
1800
1900
2000
0 - 10
21
79
101
58
100
13
o"1""1
0
0
0
1
0
b"
373
-
0
1
21
56
31
._37
37
5
1
0
0
0
0
189
** 2000
20 - 30
0
0
0
0
1
I . .
15
18
10
3
2
1
' 0
51
- 2400
PST
40 *
0
0
0
0
0
.. o .
1
13
14
15
8
4
4
59
0
0
0
0
0
... o..
0
1
1
8
1
2
1
14
50 -
0
0
0
0
0
... o
0
0
0
1
u
1
1
3
60 - 70 - 80 - 90 - 100
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
0
0
0
. 0
0
0
0
0
0
0
0
0
0
u
u
u
J
0
o
J
\J
u
u
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
TOTAL
tl
6U
122
114
132
. 51
53
37
26
27
12
9
6
6*0
Ul
C2H2 UG/M3 ** NO >= 60 U&/*3
CH4 UG/M3 0 -
700- <
800- <
900- <
1000- <
1100- <
1200- <
1300- <
1400- <
1500- <
1600- <
1700- <
1600- <
1900- <
TOTAL
800
900
1000
1100
1200
1300
1400
1500
1600
17CO
1800
1900
2000
4
23
52
34
113
33
9
3
1
... 0 .
0
0
0
272
10 - 20 - JO - 4C - 50 - 60 - . 70 - 80 - 90 - 1UO
0
1
16
. 39
73
106
. 59
24
13
8 .
0
1
1
341
0
0
0
0
" I..
21
47
30
26
_. 7
1
2
3
138
0
0
0
0.
0
2
5
17
18
17 .
5
8
7
79
0
0
0
0
0
1
1
1
2
9
1
2
4
21
0
0
0
0
0 '
0
0
0
0
. 1
0
1
1
3
0
0
0
0
0
0
0
0
0
0
1
1
0
2
0
0
0
0
0
0
1
0
0
0
0
0
0
1
0
0
0
0
u
0
0
0
0
J
u
J
J
0
u
0
0
0
0
0
0
o
0
0
0
0
0
0
TOTAL
4
24
60
73
Io7
163
122
75
60
42
8
15
16
b&7
-------
TABLE 12e. JOINT DISTRIBUTION OP ACETYLENE AND METHANE
e. OZONE ABOVE STANDARD.
In
K>
C2H2 UG/M3 ** 03 > =
CH4 UG/M3
700- <
800- <
900- <
1000- <
1100- <
1200- <
1300- <
1400- <
1500- <
1600- <
1700- <
1800- <
1900- <
TOTAL
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
0 -
55
135
122
51
... - 7
4
1
4
1
1
. . 0
0
0
381
• 16U UG/M3
Itl - 20 - 30 - 40 -
0
0
0
14
4
9
4
8
10
1
0
0
0
50
0
0
0
0
. 0
0
0
3
2
2
0
0
0
7
0
0 •
0
0
0
0
0
0
4
4
0
0
0
8
0
0
0
0
.. Q
' 6
0
1
0
0
0
0
0
. I
50 - 60 - 70 - 80 - 90 -
0
0
0
0
0
0
0
0
0
0
0
0
'0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.. o
0
0
0
U
0
0
0
0
0
U
0
0
J
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
100
TOTAL
55.
135
122
65
U
5
16
17
8
0
0
U
447
-------
TABLE 13ab.
JOINT DISTRIBUTION OF ETHANE AND METHANE
a. ALL REDUCED DATA, b. MORNING.
in
CH4 UG/M3
700- <
faQO- <
900- <
1000- <
1100- <
1200- <
1300- <
1400- <
1500- <
1600- <
1700- <
1800- <
1900- <
TOTAL
800
900 "
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
CH4 UG/M3
700- <
800- <
900- <
1000- <
1100- <
1200- <
1300- <
1400- <
1500- <
1600- <
1700- <
•1800- <
1900- <
TOTAL
800
900
1000
1100
1200
.1300
1400
1500
1600
1700
1800
19CO
2000
C2H6
6 -
270
583
340
231
616
99
7
2
5
1
3
' 1
1
215?
C2H6
"b -
18
56
44
17
71
30
0
0
0
1
0
0
0
237
UG/M3
10 -
1
2
241
. 315
156
287
182
36
9
3
1-
1
3
1237
UG/M3
10 -
0
0
30
32
20
38
22
5
2
0
0
0
0
149
**
20 - 30
0
0
0
4
40
.27
63
91
41
9
1
1
0
277
** 0600
20 - 30
0
0
0
0 '
11
12
6
7
8
1
0
1
0
46
40 -
0
0
0
0
0
6
12
14
35
39
3
3
3
115
- 090C PST
40 -
0
0
0
0
0
0
0
0
0
9
1
0
0
10
0
0
0
0
0
0
1
8
4
17
17
11
4
62
0
0
0
0
0
0
0
0
0
0
0
6
2
8
50 -
a
0
0
0
u
0
0
8
20
3
4
7
3
45
50 -
0
0
0
0
0
0
0
0
0
0
0
0
0
0
60 -
0
0
0
0
0
0
0
1
1
13
1
5
7
28
60 -
0
0
0
0
0
0
0
0
0
0
0
0
0
0
70 -
0
0
0
0
0
0
0
0
0
0
0
0
u
0
70 -
0
0
0
0
0
0
0
0
0
0
0
0
0
0
80 -
0
0
J
0
0
0
t)
0
1
0
0
0
a
1
80 -
u
0
0
0
0
0
J
0
0
0
J
0
0
0
9U -
0
0
0
0
0
0
0
u
0
0
0
0
0
0
90 -
0
u
0
6
0
0
0
0
0
0
0
0
0
0
100
TOTAL
271
100
5t»l
550
612
419
265
IbU
116
30
29
21
3924
TOTAL
Iti
5t>
74
102
8G
16
12
10
11
1
7
2
4i>U
-------
TABLE 13c. JOINT DISTRIBUTION OP ETHANE AND METHANE
c. EVENING.
CH4 UG/M3
700- <
BOO- <
900- <
1000- <
1100- <
1200- <
1300- <
1400- <
1500- <
1600- <
1700- <
1800- <
1900- <
TOTAL
800
900
1000
1100
1200
1300
1400
15CO
1600
1700
1800
1900
2000
C2H6
UG/M3
** 2 COO
-, 2400
PST
0 - 10 - 20 - 30 - 40 - 50
21
78
83
31
92
4
0
0
0
0
1
0
o
310
0
1
37
83
37
47
24
1
0
1
0
0
0
231
V 0
0
0
0
3
0
28
22
5
0
0
0
0
58
0
0
0
0
0
0
1
4
9
7
0
1
0
22
0
0 ,'.
0
0
0
- 0 .
0
5
2
10
8
0
1
26
60..- 70 r 80 - 90 - 100 TOTAL
0
0
0
0
0
0 .
0
5
9
0
2
5
1
22
0
0
0
0
0
0
0
0
0
9
1
3
4
17
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
J
0
J
y
J
0
1
u
0
0
0
1
0
0
u
0
0
0
a
0
0
0
0
0
0
0
21
7V
120
ilH
132
51
53
37
2d
27
12
9
6
6fa7
-------
TABLE 14. JOINT DISTRIBUTION OF OZONE AND OXIDANT.
OX UG/M3
0- < 50
50- < 100
100- < 150
150- < 200
200- < 250
250- < 300
300- < 350
350- < 400
400- < 450
450- < 500
03
0 -
2438
49
0
0
..." , 0-
•'••••••••'• o
0
0
0
0
UG/M3 **
50 - 100
188
428
21
0
0
0
0
0
0
0
TOTAL 2487 637
TABLE ~15a. JOINT DISTRIBUTION OF
a. ALL REDUCED DATA
NOX UG/M3
0- < 50
50- < 100
100- < 150
150- < 200
200- < 250
250- < 300
300- < 350
350- < 400
400- < 450
450- < 500
500- < 550
550- < 600
600- < .650
650- < 700
700- < 750
750- < 800
800- < 850
850- < 900
900- < 950.
950- < 1000
TOTAL
03
0 -
280
1)86
699
527
406
269
170
92
76
47
• 47
27
13
9
11
. • 2
" -• 3
2
1
0
3269
U6/M3 **
50 - 100
190
271
135
67
35
29
17
7
3
1
0
0
0
0
0
0
0
1
2
0
758
0
51
275
•''. 22
0
0
0
0
0
0
150 - 20C
. 0
0
40
159
8
0
0
0
0
0
348 207
OZONE AND NOX
87
220
49
29
12
.2
5
1
0
0
0
0
0
0
0
0
0
0
0
0
405
150 - 200
49
67
43
19
• 7
1
4
0
0
0
0.
0
0
0
0
0
.0
0
0
0
210
0
0
2
73
105
4
0
0
0
0
184
26
107
27
18
5
0
1
0
'• o
0
0
0
0
0
0
0
0
0
0
0
184
250 -
0
0
0
3
66
67
4
0
. 0
0
140
250 -
3
90'
28
16
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
140
300 -
0
0
0
0
2
22
30
3
0
0
57
300 -
0
34
21
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
u
57
350 -
0
0
0
0
o
5
26
15
0
0
46
350 -
, 0
21
19
3
0
1
0
1
1
0
0
0
0
0
0
0
0
0
0
0
46
400 - . 450 -
0
o
0
0
0
0
4
U
6
0
22
400 - 450 -
0
10
9
2
1
J
0
0
0
0
0
J
J
0
0
0
0
J
u
0
21
0
0
0
0
0
0
0
0
0
1
1
0
"0
1
0
"o
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
500 TOTAL
2626
526
338
2i>7
161
98
64
30
6
1
4129
500 TOTAL
635
1423
1031
663
468
303
197
101
80
4tt
47
27
U
9
11
2
3
3
3
0
5092
-------
TABLE 15b. JOINT DISTRIBUTION OF OZONE AND NO*
b. NMEO ABOVE STANDARD
Ul
NOX UG/M3
0- < 50
50- <
100- <
150- <
200- <
250- <
300- <
350- <
400- <
450- <
5 00-" <"
550- <
600- <
650- "<"
700- <
750- <
800- <
850- <
900- <
950- <
TOTAL
100
150
200
250
300
350
400
450
500
550
600
650
700"
750
800
850
900
950
1000
03 UG/M3 ** C2H4+C2H2+C3* > 160 UG/M3
<>•- 50 - 100 - 150 - 200 - 250 - 300 -
18 17 12 23 9 2 0
258
561
454
354
245
153
8.7
72
44
44
27
12
9
11
2
•" ' 3
2 ..,
1
0
2357
146
120
65
32
26
16
7
3
1
a
0
0
0
0
0
0
i
: ".: • 2
0
436
126
40
25
11
2
5
1
0
0
0
0
0
0
0
o .
0
0
0
0
222
54
29
18
7
0
4
0
0
0
0
0
0
0.
0
0
0
0
0
0
135
64
22
18
5
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
119
57
21
'14
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
96
24
19
2
0
0
0
p
0
0
0
0
0
0
0
0
0
0
0
0
45
350 - 400 -
0 0
20 " • 8
14 6
3 2
0
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
39
1
0
0
0
0
0
0
0
v)
0
0
0
0
0
0
0
19
45J - 500 TOTAL
0 til
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
757
835
601
411
274
179
96
76
45
44
27-
12
9
11
2
3
3
3
0
' 3469
-------
REFERENCES
1. Air Quality Criteria for Nitrogen Oxides, EPA AP 84, 1971-
2. Dimitriades, Basil, Environ. Sci- Technol., 6_, (3) (March 1972), p. 253.
3. Stephens, E. R. and Burleson, F. R., JAPCA, 19, 92,9, 936 (1969).
4. Schuck, E. A., Altshuller, A. P., Earth, D. S. and Morgan, G. B., J.
Air Pollut. Control Assoc., _20, 5, 297-302 (1970).
5. Federal Register, Vol. 36, No. 67, 7 April 1971. Federal Register,
Vol. 36, No. 158, 14 August 1971. Appendix J.
6. National Academy of Sciences, Committee on Motor Vehicle Emission
Standards, A Critique of the 1975-1976 Federal Automobile Emission
Standards for Hydrocarbons and Oxides of Nitrogen.
7. Winer, A. M., Peters, J. W., Smith, J. P. and Pitts, J. N. Jr., Environ.
Sci. Technol., December 1974, p. 1118.
8. Monitoring and Air Quality Trends Report, 1974, Pub. No. EPA-450/1-76-001
(1976).
9« Emission Inventory 1973. California Air Resources Board, August 1976.
10. Report 1977, South Coast Air Quality Management District, El Monte,
California (LA Times).
11. Air Quality Handbook for Environmental Impact Report, South Coast
Air Quality Management District, El Monte, California 1977.
57
-------
APPENDIX
"•" iv* J
Back Extrapolation
An obvious criticism of the direct correlation of oxidant/ozone with
NMHC/NOx in the same sample is that the same chemistry which produces
ozone will destroy NMHC and perhaps NOx. This argument might also explain
any discrepancy between ambient data and inventory data. This project
offered means to verify and allow for this because it provides two indepen-
dent measures of degree of reaction and clearly indicates samples which have
-Sr
undergone little or no reaction*
*f 1) Since ethene and acetylene are derived almost exclusively from
car exhaust they must enter the atmosphere (unless the air sample inadver-
tently comes mainly from one atypical vehicle) in a consistent ratio*
Ethene is several times more reactive than acetylene so extensively reacted
mixtures show a significant decrease in the ethene/acetylene ratio.
2) Combustion sources produce NO predominently which is converted
by atmospheric chemistry to N02« There is neither experimental nor theoret-
ical reason to believe that NO is ever reformed by any process in the real
atmosphere even though "pure" NC>2 can be photolyzed to NO in laboratory
systems.
Assume that the relative/fractional rates of disappearance of indi-
vidual hydrocarbons are always the same and independent of degree of reac-
tion, brightness of sunlight and other factors. This can be symbolized by a
free radical concentration [R] which might be thought of as OH although
the following derivation is not dependent on the assumption that OH is
actually that attacking species.
+ R loss of hydrocarbon k^
58
-------
dt
when [Ci_] = concentration of hydrocarbon i
k£ = rate constant for hydrocarbon i
reaction with R
[R*] = concentration of attacting free radical
[C^o] = Initial concentration of hydrocarbon i
[Cio3 = [Ci]exp k^[R] dt (1)
If this is applied to ethene ([CEtjO] -»• [CEt])
and acetylene ([Cac>o] -»• [Cac] )
the integral can be evaluated
f0 [R] dt = [kEt - kac]-l ln[CEto] [CacJ [CaCj0]-l [CEt]-l
If (1) is summed over all hydrocarbons
- £[C±]exP ki/S[R] dt = £[CiJ £f± exp ki/S[R] dt
In which f^ = [C^]/^[C^] represents the fraction of the hydrocarbon which has
reactivity k^. These fractions refer to the hydrocarbons composition in the
reacted state as measured* In the most reacted samples the ethene was reduced to
about half of the acetylene value. Using rate constants for the reaction of
OH with ethene (3.8 x 109 i mole"1 sec"1) and acetylene, (0.11 x 109 i
mole"1 sec""1) we can estimate the value of the integral:
Jo[R]dt = ln 2 = 1.9 x 10"10 H mole"1 sec"1
3.7 x 109
59
-------
*K. R. Darnall, A. C. Lloyd, A. M. Winer and James N. Pitts, Jr.
Env. Sci. and Tech. 10, p. 692, July 1976
To estimate the "depletion factor"
exp
an estimate of hydrocarbon distribution, f^, with reactivity k^ is needed.
A simplifying assumption is that the highly reactive olefins are completely
reacted but present in small quantitites to begin with so they are ignored.
The remainder may be split 2/3 paraffins of OH reactivity equal to ethene
and 1/3 aromatics with twice the reactivity of ethene then the depletion
factor will be nearly three. The joint distribution tables 8a,b,c do not
suggest a loss of higher hydrocarbons of this magnitude.
It also was assumed that the atmosphere operated as a batch reactor.
Since additions of organlcs continue during daylight hours a stirred flow
reactor equation would be more appropriate. This probably would make
little difference as long as the ethene/acetylene ratio is used as the
measure of degree of reaction and the assumption is made that the bulk of
the higher hydrocarbon has a reactivity not differing greatly from ethene.
60
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1' RtP°AR-T6(!>&/3-79-076
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
OXIDANT-PRECURSOR RELATIONSHIPS
5. REPORT DATE
August 1979
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Edgar R. Stephens and Oscar P. Hellrich
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Statewide Air Pollution Research Center
University of California
Riverside, California 92521
10. PROGRAM ELEMENT NO.
1AA603A AD-011 FY-78
11. CONTRACT/GRANT NO.
R-803799
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Sciences Research Laboratory-RTF, NC
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
13.
OJF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/600/09
15. SUPPLEMENTARY NOTES
16. ABSTRACT
New methods of ambient air analysis were used to define more clearly the
relationships between oxidants and their precursors. Non-methane hydrocarbons,
NOX, 02, and oxidants were measured at the same time and location (Riverside,
California). The ambient air data presented in this report are displayed as a
series of conditional joint distributions. The correlations range from
excellent—ozone vs oxidant—to poor or bimrodal—ozone with non-methane-
ethane organics (NMEO) or with NOX. The ratio of NMEO to NO was always higher
than indicated by inventories and showed a large scatter. No depletion of NMEO
with respect to acetylene could be detected.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
*Air pollution
* Nitrogen oxides
* Hydrocarbons
* Ozone
* photochemical reactions
* Relations (mathematics
13B
Q7B
Q7C
07E
12A
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
21. NO. OF PAGES
73
20.
22. PRICE
EPA Form 2220-1 (9-73)
01
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