&EPA
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
EPA 600 2-78 004k
May 1978
Research and Development
Source Assessment:
Coal Storage Piles
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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 ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-004k
May 1978
SOURCE ASSESSMENT: COAL STORAGE PILES
by
T. R. Blackwood and R. A. Wachter
Monsanto Research Corporation
1515 Nicholas Road
Dayton, Ohio 45407
Contract No. 68-02-1874
Program Element No. 1BB610
Project Officer
John F. Martin
Resource Extraction and Handling Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental
Research Laboratory-Cincinnati, 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 Protectidri Agency, nor does mention Of
trade names or commercial products constitute endorsement or
recommendation for use.
n
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FOREWORD
When energy and material resources are extracted/ processed, con-
verted, and used, the related pbllutional impacts on our environ-
ment and even on our health often require that new and increasingly
more efficient pollution control methods be used. The Industrial
Environmental Research Laboratory - Cincinnati (lERL-Ci) assists
in developing and demonstrating new and improved methodologies that
will meet these needs both efficiently and economically.
This report contains an assessment of air emissions from coal
storage piles. This study was conducted to provide sufficient
information for EPA to ascertain the need for developing control
technology for this source. Further information on this subject
may be obtained from the Extraction Technology Branch/ Resource
Extraction and Handling Divisioni
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
ili
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PREFACE
The Industrial Environmental Research Laboratory (IERL) of the
U.S. Environmental Protection Agency (EPA) has the responsibility
for insuring that pollution control technology is available for
stationary sources to meet the requirements of the Clean Air Act,
the Water Act and solid waste legislation. If control technology
is unavailable, inadequate, uneconomical or socially unacceptable,
then financial support is provided for the development of the
needed control techniques for industrial and extractive process
industries. Approaches considered include: process modifications,
feedstock modifications, add-on control devices, and complete pro-
cess substitution. The scale of the control technology programs
ranges from bench- to full-scale demonstration plants.
IERL has the responsibility for developing control technology
for a large number (>500) of operations in the chemical and re-
lated industries. As in any technical program, the first step
is to identify the unsolved problems. Each of the industries is
to be examined in detail to determine if there is sufficient
potential environmental risk to justify the development of con-
trol technology by IERL. This report contains the data necessary
to make that decision for coal storage piles.
Monsanto Research Corporation (MRC) has contracted with EPA to
investigate the environmental impact of various industries which
represent sources of pollution in accordance with EPA's responsi-
bility as outlined above. Dr. Robert C. Binning serves as MRC
Program Manager in this overall program entitled "Source Assess-
ment," which includes the investigation of sources in each of four
categories: combustion, organic materials, inorganic materials,
and open sources. Dr. Dale A. Denny of the Industrial Processes
Division at Research Triangle Park serves as EPA Project Officer
for this series. This study of coal storage piles was initiated
by lERL-Research Triangle Park in May 1974; Mr. David K. Oestreich
served as EPA Project Leader. The project was transferred to the
Resources Extraction and Handling Division, lERL-Cincinnati, in
October 1975; Mr. John F. Martin served as EPA Project Leader
through completion of the study.
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ABSTRACT
This report describes a study of air pollutants emitted from
coal storage piles. The potential environmental effect of this
emission source is evaluated.
Coal storage piles are open sources of atmospheric emissions of
fugitive dust and gaseous hydrocarbons. Of the criteria pollu-
tants, carbon monoxide, hydrocarbons, and particle matter are
emitted. Concentrations of carbon monoxide and hydrocarbons are
three orders of magnitude below ambient air quality criteria at
a distance of 50 meters from the pile. The average emission
factor for respirable particulate (<7 ym) is 6.4 mg/kg per year.
From the distribution of coal piles, a representative pile was
selected containing 95,000 metric tons of bituminous coal. The
emission rate from this pile averages 19 mg/s or 610 kg/yr. In
order to evaluate the potential environmental effect of coal
storage piles, a source severity factor was defined as the ratio
of the maximum ground level concentration of an emission to the
ambient air quality standard for criteria pollutants and to a
modified threshold limit value for other pollutants. Severity
factors for a representative coal storage pile are 0.025 and 1.0
when the emissions are treated as gross particulate and coal dust,
respectively.
The national emission burden from all coal storage piles is
0.00048% of total national particulate emissions. The amount of
coal stored is increasing at the rate of 3.8% per year and this
will result in a 25% increase in emissions in 1978 compared to
1972.
Air pollution control techniques for coal storage piles have not
been generally established and no future control techniques are
presently under consideration.
This report was submitted in partial fulfillment of Contract No.
68-02-1874 by Monsanto Research Corporation under the sponsorship
of the U.S. Environmental Protection Agency. This report covers
the period May 1974 to September 1975, and the work was completed
as of July 1977.
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CONTENTS
Foreword
Preface v
Abstract >_Y
Figures viii
Tables ix
Abbreviations and Symbols _xi
Conversion Factors and Metric Prefixes xiii
I Introduction 1
II Summary 2
III Source Description 4
A, Process Description 4
1. Emission Sources 4
2. Source Composition 5
Bf Factors Affecting Emissions 9
C. Geographical Distribution of Coal Storage Piles 11
IV Emissions 13
A. Selected Pollutants 13
B. Mass Emissions 15
C. Representative Source 15
D. Environmental Effects 17
1. Ground Level Concentration 17
2. Hazard Factor 18
3. Source Severity 18
V Control Technology 20
A. State of the Art 20
B. Future Considerations 20
VI Growth and Nature of the Industry 22
A. Present and Emerging Technology 22
B. Coal Storage Trends 22
References 24
Appendices
A. Analysis of Sampling Results 27
B. Factors Affecting Coal Storage Emissions 36
C. Derivation of Surface Area from Height of
Coal Piles 49
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CONTENTS (continued)
Appendices (continued)
D. Sampling Equipment and Procedures 51
E. Computation of Combined Errors 62
F. Determination of Distance to Plant Boundary and
Population Density for Representative Coal
Storage Pile 64
G. Analysis of Coal Storage Piles for Polycyclic
Organic Materials 65
H. Derivation of Source Severity Equations 67
Glossary 81
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FIGURES
Number Page
1 Map of P-E values for state climatic divisions 10
2 Distribution of coal piles 12
3 Distribution of quantity of coal stored versus
P-E region 12
4 Area affected down to a severity of 0.1 19
A-l March sampling arrangement, Runs Cl and C2 28
A-2 August sampling arrangement, Runs CS-3 and CS-5 28
D-l Fugitive dust sampling worksheet 61
IX
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TABLES
Number Page
1 Concentrations of Trace Metals in Coal and Coal Dust 7
2 Composite TLV of all the Elements in Coal Dust 8
3 Analysis of Grab Samples for Total Hydrocarbons,
Methane, Carbon Monoxide and Sulfur (AS H2S,
SO2 and RS) 14
4 State and National Emissions 16
5 Comparison of the Representative Coal Storage Pile
to the Pile Selected for Sampling 17
6 Source Severity 19
A-l Sampling Results - March and August 1974 30
A-2 Data for Calculation of the Constant (k) 33
A-3 X-ray Fluorescence Analysis of Samples from Filters 34
A-4 Particle Size Analyses 35
B-l Sensitivity Analysis of Entrainment/Emission Rates
Calculated Using Equation B-18 with Average,
Minimum and Maximum Values for Wind Velocity,
Bulk Density, P-E Index and Surface Area 47
C-l Height of Coal Piles 50
D-l Open Sources Sampling Guidelines 58
D-2 Placement of Samples Downwind of Obstructions 59
D-3 Fugitive Dust Sampler and Meteorological Data Log 60
F-l Distance to Plant Boundary and Population Density
for Representative Coal Storage Pile 64
G-l Analysis of Coal Samples Extracted with Pentane
for Selected Polycyclic Organic Materials (POM's)
by Chemical lonization Ma<== gpectroscopy 66
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TABLES (continued)
Number Page
H-l Pollutant Severity Equations 68
H-2 Values of a for the Computation of a 70
H-3 Values of the Constants used to Estimate Vertical
Dispersion 70
H-4 Summary of National Ambient Air Quality Standards 76
XI
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ABBREVIATIONS AND SYMBOLS
a, ..., g, — variable exponents and coefficients used in
m, n numerous mathematical manipulations
A, ..., G — stability classes; also used to designate
reference distances for hi-volume samplers
AL — leading angle at the base of a coal dust bed
AR, BR — substitution variables
Bl, B2 — particle size samples
Ci — concentration of the i-th chemical element
C, C1 — local wind erosion climatic factor
Cl, C2, — valid hi-volume sampler runs
CS-3, CS-5
D — representative distance
d — distance across a field
Do — annual days of operation of a facility
storing coal
Ds — average days of supply of coal stored at a
facility
E — potential average annual soil loss
EN* ESO/ '— variables used by different authors to
Ep, ES/ EA represent entrainment rate
exp — natural log base, e — 2.72
E2/ £3, EH —• credibility factor functions
F — hazard factor
FC — total concentration of all i-th chemical
elements in the dust
Fu — frictional velocity
Gl, G2, — gas sample numbers
•••/ G12
H — height of a coal dust bed
h — height of emission
I — soil and knoll erodibility index
K, K" — surface and ridge roughness
KI, ..., K7 — constants
L! — unsheltered distance across a field
along the prevailing wind direction
M — moisture content
n — number of samples collected
N — number of chemical elements
P — monthly precipitation
P-E index — regional precipitation-evaporation level (as
expressed by Thornthwaite (Reference 13)
xii
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ABBREVIATIONS AND SYMBOLS (continued)
ppm — parts per million
Q — emission rate
Qj — final air flow rate
Q£ — initial air flow rate
S — source severity
s — surface area
SD — size distribution
SQ, .../ St,. — hi-volume sampler numbers
T — monthly mean temperature
t — "Student t" value for n - 1 degrees of freedom
TC — weight of coal stored
T^ — TLV of the i-th chemical element
tL — sampling time for which concentrations for
longer periods are calculated
TLV — threshold limit value of a material
TM — composite TLV of a compound
tmax — sampling time for which *max was determined
ts — sampling time
u — arithmetic mean wind speed
uave — average wind speed
UL — wind velocity at the midheight of a coal
dust bed
V — volume of a coal dust bed
V — vegetative cover
Va — volume of air sampled
v, u, uave» — variables used by different authors for wind
Vp speed or velocity
W — width of a coal dust bed
W. — initial (tare) weight of filter
W. — final weight of filter
X_ —- any average value
X — arithmetic mean measure of any value, X
x, y, z — downwind coordinate distances
if — a constant approximately equal to 3.14
p, — bulk density
a —• estimated population standard deviation
a — standard deviation of plume dispersal in
horizontal plane
a — standard deviation of plume dispersal in
vertical plane
X — concentration
— maximum concentration
— mean ambient concentration
xm
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CONVERSION FACTORS AND METRIC PREFIXES
CONVERSION FACTORS
To convert from
degree Celsium (°C)
kilogram (kg)
kilogram (kg)
meter (m)
meter (m)
meter (m)
meter2 (m2)
meter3 (m3)
meter3 (m3)
meter3 (m3)
meter3 (m3)
metric ton
pascal (Pa)
pascal (Pa)
radian
Prefix Symbol
kilo k
centi c
milli m
micro y
to
degree Fahrenheit (°F)
grain (1/7,000 Ib mass
avoirdupois)
pound (mass)
foot
inch
yard
mile2
foot3
inch3
liter
yard3
ton
inch of water (60°F)
pound-force/inch2 (psi)
degrees
METRIC PREFIXES
Multiplication
fadtor
103 1 kg =
10"2 1 cm =
10" 3 1 mm =
10~6 1 ym =
Multiply by
tn = 1.8t.^ + 32
°F C
1.543 X 10k
2.205
3.281
3.937 x 101
1.094
3.861 x 10~7
3.531 x 101
6.101 x 10k
1.000 x 10~3
1.308
1.102 x 103
4.019 x 10~3
1.450 x I0~k
5.730 x 101
Example
1 x 10 3 grams
1 x 10~2 meter
1 x 10" 3 meter
1 x 10~6 meter
Metric Practice Guide. ASTM Designation E 380-74, American Society for
Testing and Materials, Philadelphia, Pennsylvania, November 1974. 34 pp.
XIV
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SECTION I
INTRODUCTION
Coal storage piles contribute fugitive emissions to the atmos-
phere in the form of coal dust. The severity or potential
environmental risk of emissions from these piles and other open
sources had been ranked relative to each other through the use of
an impact factor. This factor is a measure of the local population
density that is exposed to the maximum concentration of all emis-
sions from coal storage piles relative to the hazardous nature
of each emission. Although the impact factor was low for coal
storage piles compared to other open sources, coal storage was
investigated as a prototype for development of the logic and
methods to be used in the future assessment of various other
source types. It also served to test the consistency of the
logic applied.
An analysis of coal storage piles was conducted to assess the
distribution and character of emissions in greater detail than
is available in the literature. The emphasis of the assessment
has been to ascertain whether control technology development is
required. The following data are compiled in this document:
• The number of coal storage piles
• Distribution of coal storage in the U.S.
• A documented emission factor
• The composition of emissions
• The hazard potential of emissions
• The factors which affect the emissions
• Total national emissions
• Contribution to state emissions burden
• A relative severity factor (used in comparing other
source assessments)
• Type of control technology used and proposed
• Growth of coal storage piles
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SECTION II
SUMMARY
Coal storage piles are open sources of atmospheric emissions
of fugitive dust and gaseous hydrocarbons. The emission rate
varies due to meteorological and topographical influences. Of the
criteria pollutants, carbon monoxide, hydrocarbons, and particulate
matter are emitted. The concentrations of carbon monoxide and
hydrocarbons are three orders of magnitude below ambient air
quality criteria at a distance of 50 m (164 ft) from the coal pile.
Thus, a detailed analysis of the severity was not required. The
respirable particulate matter (<7 ym) emitted is coal dust, which
has a threshold limit value (TLV®) of 2 mg/m3. These emissions
were found to be affected by wind speed, surface area of the pile,
coal density, and regional precipitation evaporation (P-E) index.
However, a sensitivity analysis indicates that these parameters
do not preclude the use of an average emission factor of 6.4 mg/kg
(0.013 Ib/ton) per annum. This factor describes the emission rate
within 6.9 mg/kg (0.014 Ib/ton) per annum, 95% of the time.
From a study of the distribution of coal piles, a representative
coal pile was defined as containing 95,000 metric tons3
(100,000 tons) of bituminous coal with an average pile height of
5.8 m (19 ft). It is located in a P-E region with an annual index
of 91 (U.S. average) and an annual average wind speed of 4.5 m/s
(10 mph). The emission rate from this pile averages 19 mg/s
(0.15 Ib/hr) or 610 kg/yr. The severity of the representative
pile is 0.025 when the emissions are considered as gross
particulate, and 1.0 when treated as coal dust. The population
affected, above a severity of 0.1, is 58 persons.
The national emission burden from coal storage piles is 630
metric tons/yr (690 tons/yr) or 0.00048% of total national
particulate emissions. No state has an emission burden from
this source of greater than 0.0026% of the state's total
particulate emissions.
1 metric ton = 106 grams - 2,205 pounds =1.1 short tons (short
tons are designated "tons" in this document); conversion factors
and metric system prefixes are presented in the prefatory pages
of this report.
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In 1973, over 98 x 106 metric tons (108 x 106 tons) of coal was
reportedly stockpiled at over 950 user sites located in 479 coun-
ties at coke plants, electric generating stations, and industrial
boiler facilities. The amount of coal stored is increasing at the
rate of 3.8% per year, mainly due to the construction of new coal-
fired plants. This trend will result in an increase in emissions
of 25% in 1978 compared to 1972.
Air pollution control techniques for coal storage have not been
generally established and no future control techniques are
presently under consideration.
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SECTION III
SOURCE DESCRIPTION
A. PROCESS DESCRIPTION
1. Emission Sources
The term coal storage refers to over 98 x 106 metric tons of
coal stockpiled at coke plants, electric generating stations,
and industrial boilers (1-4). There are over 950 of these
facilities reportedly using coal and maintaining coal storage
piles. Coal mines do not stockpile coal because of safety hazards,
Bureau of Mines regulations, and the mechanization at today's
mines. Coal is either conveyed directly from the mine to the
user, i.e., coke plant, or to the cleaning plant for transport
to the user. Cleaning plants store coal in bins to facilitate
transport and handling; little if any storage occurs in the open
(personal communication with Mr. O'Brien, American Mining
Congress, Environmental Matters Dept., July 30, 1974). The
amount of coal stored is a function of the type of facility
operated. Average coal storage supplies are as follows:
User
Coke plants
Electric utility
stations
Industrial
Average days
of supply (Ds)
23 (5)
92 (7)
37 (5)
Effective
August 1974
May 1974
August 1974
Annual dayS Of
operation
365 (6)
365 (7)
205a
Estimated value based on authors' industrial experience.
(1) Keystone Coal Manual, 1973. McGraw-Hill, Inc., New York,
New York, 1973. pp. 304-410.
(2) Electric Utility Statistics. Public Power, 32:28-74, January-
February 1974.
(3) Steam-Electric Plant Factors/1973 Edition. National Coal
Association, Economics and Statistics Division, Washington,
D.C., December 1973. 110 pp.
(4) Coke Producers in the United States in 1972. Mineral
Industry Surveys. U.S. Department of the Interior,
-------
The weight of coal stored is calculated from the product of the
annual consumption of coal per user (1-4) and the ratio of
average days of supply to annual days of operation (D /D ).
s o
Fugitive dust is emitted from an open coal storage pile via wind
and other weathering forces acting on the surface. This process
is similar to wind erosion of soil and this document uses many
of the concepts already developed by other investigators of such
phenomena to determine emissions from coal piles. Particulates
are the most generally recognized of the emissions, but gaseous
materials also emanate from coal storage piles by oxidation of
the exposed coal and the release of pressure on the solid due
to mining and comminution. Some volatile emissions are also
generated during the weathering process. These gases may cause
some odor at the pile; however, the chemical species which may
contribute to this odor are not detectable at hazardous concen-
trations. Thus odor is not considered in this study.
2. Source Composition
There are four major classes of coal: 1) lignite, 2) bituminous,
3) subbituminous, and 4) anthracite (8). Coal usage breaks down
as follows (9):
Usage,
Class 103 metric tons
Bituminous 330
Subbituminous 200
Lignite 10
Anthracite 6.4
Since anthracite and lignite account for less than 1*2% and 1.8%,
respectively of the coal used in the United States (9), only the
bituminous and subbituminous classes will be considered in this
report.
Washington, D.C., November 27, 1973. pp. 2-5,
(5) Rumblings from the Mines. Time Magazine, 104(9):35,1974.
(6) Sheridan, E. T. Coke and Coal Chemicals. In: 1972 Miner-
als Yearbook, A. E. Schreck, ed. U.S. Department of the
Interior, Washington, D.C., 1972. pp. 427-460.
(7) FPC Issues Electric Fuel Consumption Stocks. News Release
No. 20499, Federal Power Commission, Washington, D.C.,
July 22, 1974 . 3 pp.
(8) A.S.T.M. Standards on Coal and Coke. American Society for
Testing and Materials, Philadelphia, Pennsylvania, September
1948. p. 80.
(9) Minerals Yearbook, 1973, Volume I. U.S. Department of the
Interior, Washington, D.C., 1973. pp. 8-36.
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Coal seams vary in physical and chemical properties across the
U.S. However, coal dust is considered hazardous only on a mass
basis and not by virtue of its composition. A TLV of 2 mg/m3
applies to all classes of coal (10). Brown, Jacobs and Taylor (11)
have studied trace elements in coal and coal dust. Table 1 has
been developed from their data (10, 11). These results indicate
that the heavier elements tend to concentrate in this dust. To
determine the possible effect of these findings on the hazardous
nature of the emissions from coal piles, a composite TLV (10) was
calculated, using Equation 1 below, and compared to that of coal
dust. The composite TLV of the mixture (T^) was determined in
order to take into account the effects of trace elements and
other chemical compounds present in the coal dust. The TLV's of
the metals and chemical forms that occur most frequently in coal
dust (Table 2) were used for this analysis.
N
where FC = £ Ci = total concentration of all
i=l elements in the dust
Ti = TLV of the ith element
C. = concentration of the ith element (shown in Table 1)
N = number of elements, as given in Table 2
The composite TLV is thus 6 mg/m3, as shown in Table 2, or three
times that of coal dust. The largest contributor is the quartz
component (1%). Analysis of dust samples from coal piles
(Appendix A) shows that quartz is less than 1% and the composite
TLV could be expected to be higher. Thus, analysis shows that
coal dust can validly be considered the only hazardous pollutant
emitted since the composite TLV is higher than the accepted TLV
for mass coal dust.
(10) TLVs® Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment and Intended
Changes for 1973. American Conference of Governmental
Industrial Hygienists, Cincinnati, Ohio, 1973. p. 10.
(11) Brown, R., M. Y. Jacobs, and H. E. Taylor. A Survey of the
Most Recent Applications of Spark Source Mass Spectrometry.
American Laboratory, 4:34-37, November 1972.
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TABLE 1. CONCENTRATIONS OF TRACE METALS
IN COAL AND COAL DUST (11)
Element
Aluminum
Arsenic
Barium
Bismuth
Bromine
Boron
Cadmium
Calcium
Cerium
Chlorine
Chromium
Cobalt
Copper
Fluorine
Gallium
Germanium
Iodine
Iron
Lanthanum
Lead
Magnesium
Manganese
Molybdenum
Neodymium
Nickel
Niobium
Phosphorus
Potassium
Praseodymium
Rubidium
Samarium
Scandium
Selenium
Silicon
Silver
Sodium
Strontium
Sulfur
Tellurium
Titanium
Uranium
Vanadium
Yttrium
Zinc
Zirconium
Weight
ppm in coal
Major
0.30
69
0.20
0.30
42
0.19
4,000
13
130
4.5
2.3
25
5.7
8.7
0.33
0.20
1,600
5.8
3.9
4,500
30
3.0
8.3
2.7
20
380
410
4.7
3.0
1.7
1.3
0.32
Major
0.22
5,000
100
6,100
0.25
620
1.9
12
7.7
10
76
Weight
ppm in coal dust (C_-l_
283,000
26.4
453
7.50
11.3
3.80
3.80
13,200
45.3
230
170
11.3
868
1.90
68.0
18.9
3.80
79,200
22.6
26.4
792
45.3
15.1
45.3
755
7.60
306
16,600
11.1
7.60
3.80
30.2
7.60
294,000
7.60
755
291
3,130
3.80
15,800
2.26
166
7.60
415
60.4
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TABLE 2. COMPOSITE TLV OF ALL THE ELEMENTS IN COAL DUST
Element
Aluminum
Arsenic
Barium
Bromine
Cadmium
Calcium
Chlorine
Chromium
Cobalt
Copper
Fluorine
Iodine
Iron
Lead
Magnesium
Manganese
Molybdenum
Nickel
Phosphorus
Potassium
Selenium
Silicpn
Quartz
Silver
Sodium
Sulfur
Tellurium
Titanium
Uranium
Vanadium
Yttrium
Zinc
Zirconium
Other elements
Total
C -.1-. m-i-wji. IT1! / *1 •
£/ ppm T. (1.
283,000
26.4
453
11.3
3.80
13,200
230
170
11.3
868
1.90
3.80
79,200
26.4
792
45.3
15.1
775
306
16,600
7.60
284,000
10,000
7.60
775
3,130
3.80
15,800
2.26
166
7.60
415
60.4
289,000
1,000,000
i \ / 3
L) , mg/m^
10
0.5
0.5
0.7
0.2
10
3
1.0
0-1
1
2
1
10
0-15
10
5
10
1
0.1
10
0.2
10
0.2
0.01
10
2
0.1
10
0.2
0.5
1
5
5
10
b (ppm) (md)
ci' i' mg
28,301.9
52.8
906.0
16.1
19.0
1,320.8
76.7
170.0
113.0
868.0
1.0
3.8
7,924.5
176.0
79.2
9.1
1.5
775.0
3,060.0
1,660.4
38.0
28,434.0
50,000.0
760.0
77.5
1,566.0
38.0
1,585.0
11.3
332.0
7.6
83.0
12.1
28,941.7
157,421.0
i,ooo,ooob , m, 3
M 157,421
9From Table 1. \
Intermediate calculated values are not rounded; rounding is
performed on final answer.
8
-------
B, FACTORS AFFECTING EMISSIONS
The major parameters that are known to contribute to the emissions
from coal storage piles are pile geometry, coal erodibility
(dustiness), wind, humidity, precipitation and temperature. Coal
erosion has been studied in a wind tunnel and the effects of most
of these parameters, or their equivalents, evaluated. Soil
erosion equations have also been used to predict parameter
influence on coal storage emissions. A complete discussion of
these studies is provided in Appendix B. The following paragraphs
summarize the findings.
Thp effects of humidity, precipitation and temperature can be
combined into one parameter, the Thornthwaite precipitation-
evaporation (P-E) index. P-E index values are available for all
par^s of the U.S. (12) and are shown in Figure 1. The lower the
P-E index, the higher the emissions from coal piles. This
parameter has the greatest effect on emission rate. The P-E
ratio is calculated as follows:
/ PM \10/9
Monthly P-E ratio = 11.5 I-—^^-777) (2)
\M
12
P-E index = f (monthly P-E ratios)
where9 P^ = monthly precipitation, in.
TM = monthly mean temperature, °F, adjusted to a
constant of 30°F for all values below 30°F
Coal erodibility is a measure of the dustiness of the coal. It
has been shown that the bulk density of coal (P^) is an indicator
of coal dustiness. Thus, the erosion rate is a function of bulk
density which has been used as the indicator of windblown emis-
sions. The emission rate is influenced the least by this
parameter.
Two remaining parameters that can contribute to emissions from
coa}. storage piles are wind speed and pile geometry. A coal pile's
aNonmetric units are designated for Equation 2 to conform to the
system of units reported by the author (12) and commonly used.
(12) Thornthwaite, C. W. The Climates of North America Accord-
ing to a New Classification. The Geographical Review/
21:633-655, 1931.
-------
Figure 1. Map of P-E values for state climatic divisions (12).
-------
geometry can be related through its surface area. Appendix C
describes how this surface area can be calculated from the total
weight stored.
A functional relationship could be derived relating all of these
parameters to emission rate. This derivation is given in
Appendix B, but it is not rigorously applied in this document.
The rationale for this decision is given in Appendix B, which
shows that the level of emissions from storage piles is adequately
described through the use of an average emission factor which is
given in Appendix A. The functional relationship of the emission
parameters to emission rate is used to show the validity of
using an emission factor.
C. GEOGRAPHICAL DISTRIBUTION OF COAL STORAGE PILES
Figure 2 shows the distribution of coal storage piles in the
U.S. calculated as described in Section III.A.I. P-E index has
the largest effect on emission rate. A comparison between .the
total weight stored per P-E region and the P-E index shows that
90% of the coal stored is located in P-E regions with indices
between 90 and 130 (see Figure 3). This facilitates the use of
an average emission factor for use in predicting the emission
rates from the amount stored.
11
-------
700;
MEAN = 95,000 metric tons
MODE = 49,000 metric tons
200 400 600 800 1,000 1,200 1,400
SIZE OF COAL PILES, 103 metric tons
Figure 2. Distribution of coal piles.
27.2
25.4
23.6
21.8
20.0
„, 18.1
C
O
£ 16.3
E
c^ 14.5
g 12.7
2 10.9
o*
e
"" 9.1
7.2
5.4
3.6
1.8
(33.06)
(27.27)
PERCENTAGES ARE SHOWN IN ( )
(23.29)
(6.16)
(0.031
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
P-E INDEX
Figure 3. Distribution of quantity of coal stored
versus P-E region.
12
-------
SECTION IV
EMISSIONS
A. SELECTED POLLUTANTS
Wind erosion of coal storage piles results in the emission of coal
dust. Long-term exposure to coal dust is the principal cause of
coal mine workers' pneumoconiosis (13). The complicated stage of
this disease is called progressive massive fibrosis and is charac-
terized by massive destruction of lung tissue resulting in death
from heart failure, asphyxia, or pneumonia (13). A TLV of 2 mg/m3
is assigned to coal dust which is also a form of particulate matter
and one of the five criteria pollutants. Since coal dust is a
composite of various materials, the hazard potential of the compos-
ite can be calculated as the total of all ratios of trace element
concentrations to the concentration required for a hazard poten-
tial equivalent to that of mass coal dust. This was calculated to
be 6 mg/m3 as shown in Table 2. Since the hazard potential of all
trace elements is one-third the potential of mass coal dust
(2 mg/m3), further consideration of hazardous particulate emissions
beyond coal dust is not necessary.
Oxidation of coal storage piles results in gaseous emissions such
as hydrocarbons, ethane, carbon monoxide, and sulfur compounds.
However, based on the results of sampling emissions at the surface
and upwind of the pile (see Table 3), it can be seen that in all
but four cases the upwind concentration of a gas was either non-
detectable, or nearly equivalent to the concentration at the
surface of the pile. This indicates that .emissions from the pile
were quantitatively nonexistent. The maximum concentrations
reported between upwind and pile samples are not of significance
either. This can be shown by comparing samples 63 and Gi+ for
methane and total hydrocarbons, and by comparing samples GS and
Gg for carbon monoxide. These pile concentrations are reduced
(13) Brown, M. C. Pneumoconiosis in Bituminous Coal Miners.
Mining Congress Journal, 51:44-48, August 1965.
(14) Turner, D. B. Workbook of Atmospheric Dispersion Estimates.
Public Health Service Publication No. 999-AP-26, U.S.
Department of Health, Education, and Welfare, Cincinnati,
Ohio, May 1970. 84 pp.
13
-------
TABLE 3. ANALYSIS OF GRAB SAMPLES FOR TOTAL HYDROCARBONS, METHANE,
CARBON MONOXIDE AND SULFUR (AS H2S, S02 AND RS)
Concentration, ppm by
Total c
Sample description hydrocarbons
Gi
G2
G3
Gi»
G5
G6
G7
- Coal pile
- Upwind of
- Coal pile
- Upwind of
- Coal pile
- Upwind of
- Coal pile
#1
pile
#2
pile
#3
pile
#4
#1
#2
#3
3.
3.
60
3.
5.
3.
8.
5
2
9
0
0
0
Methane
1.
1.
60
1.
1.
1.
3.
5
4
6
5
6
0
volume3 i b
Carbon
monoxide
N.
N.
9.
N.
19.
1.
12.
D.d
D.
0
D.
0
0
0
Sulfur
N.
N.
N.
N.
N.
N.
5.
D.
D.
D.
D.
D.
D.
0
(No background
near power plant)
G8
G9
Gi
Gi
Gi
- Coal pile
- Coal pile
0 - Upwind of
i - Coal pile
2 - Upwind of
#5 (active) e
15 (inactive) e
pile
#6
pile
#5
#6
4.
3.
5.
4.
3.
0
0
0
5
0
3.
2.
2.
3.
4.
0
0
0
0
0
5.
1.
1.
1.
1.
0
0
0
0
0
N.
N.
N.
N.
N.
D.
D.
D.
D.
D.
Sensitivity for total hydrocarbons and methane is ±1 ppm and <1 ppm for
CO and sulfur compounds.
Samples of trapped gases, collected in glass flasks through a probe
inserted in the coal piles. This method is described in Appendix D.
CExpressed as methane equivalent.
None detected (<1 ppm).
6Active and inactive refer to the use of the pile. Inactive piles are
coated with a tar or oil to prevent oxidation.
-------
by at least three orders of magnitude at a position 50 m from
the pile (14) (with assumed stability class, C, and mean speed
of 4.5 m/s). This puts them well below ambient air quality
standards and these gases do not merit further consideration.
B. MASS EMISSIONS
The particulate emission factor for a coal storage pile has been
shown to be 6.4 mg/kg-yr (Appendix A). The use of this average
emission factor describes the emissions within 108% at the 95%
confidence level. The major influencing factor is the P-E index;
however, 90% of the coal stored is located in P-E regions of 90
to 130 (see Figure 3) which reduces the effect on emissions to
±40% from the possible ±8,500% described in Appendix B. This
emission factor is used in conjunction with the distribution of
coal storage piles (Figure 2) to give the distribution of emis-
sions. The mean emission rate will thus be 606 kg/yr. State and
national emissions burdens are given in Table 4.
For a comparison to other data in the literature, the Woodruff
and Siddoway equation referenced in Appendix B was used to
calculate an emission factor for bare, noncrusted, unsheltered
and isolated fields. This factor is 445 mg/kg-yr in comparison
to the 6.4 mg/kg-yr of coal storage piles. This is reasonable
since visual dust clouds from coal piles are rarely observed in
comparison to barren fields. Only two complaints concerning.
dust due to coal storage have been recorded, one in Illinois and
another in Minnesota9. In addition, the emissions from barren
fields contain only about 1% to 2% respirable particles (<7 ym).
Thus, the respirable emission factor for fields is 6.7 mg/kg-yr.
This is within 3% of the mass emission factor for coal piles
which is for respirable particulate.
C. REPRESENTATIVE SOURCE
The representative coal pile is defined as containing 95,000
metric tons of bituminous coal piled to an average height of
5.8 m. It is located in a P-E region of 91 index with an average
annual wind speed of 4.5 m/s and is 86 m from the nearest plant
boundary. These are the mean characteristics of all known coal
piles. The emissions from the representative pile average
606 kg/yr of coal dust.
Sampling was conducted at a coal pile containing an average of
112,000 metric tons of bituminous coal. It was located in a P-E
region of 103 index with an average annual wind speed of 3.5 m/s.
The emissions from the sampled coal pile averaged 715 kg/yr.
During the sampling period, the wind speed averaged Ii9 m/s and
aThese have never been substantiated or quantified as being from
the coal storage piles.
15
-------
TABLE 4. STATE AND NATIONAL EMISSIONS
State
West Virginia
Ohio
Pennsylvania
Indiana
Kentucky
Alabama
Tennessee
Illinois
Michigan
North Carolina
Delaware
Maryland
Wisconsin
Missouri
U.S. Total
State
emissions,
10 6 metric
tons
1.3
3.0
3.1
2.2
1.8
2.0
1.8
3.6
2.8
2.2
0.13
0.66
2.2
2.8
135
Coal
stored,
10 6 metric
tons
5.0
10
9.8
6.7
5.2
4.5
3.8
7.2
5.6
4.5
0.27
1.3
2.8
3.1
98.6
Coal
omissions,
metric tons
32
66
63
42
33
29
24
46
36
29
1.7
8.1
18
20
629
Percent
of total
emissions
0.0026
0.0022
0.0020
0.0019
0.0018
0.0014
0.0014
0.0013
0.0013
0.0013
0.0013
0.0012
0.00082
0.00070
0.00047
-------
the P-E index was estimated to average 48. It has been shown
that the factor affecting emissions is the ratio of the cube of
the wind speed to the square of the P-E index. The sampling con-
ducted is close to representative even though the wind speed and
P-E index were lower ,than the average conditions. Table 5 com-
pares the values of the factors affecting the emissions for the
representative coal storage piles, and the selected pile. There
is agreement within a factor of two during average conditions and
sampling conditions between the representative coal pile and the
pile selected for sampling. In addition, there is statistical
agreement between the average and sampling conditions for the
selected pile.
TABLE 5. COMPARISON OF THE REPRESENTATIVE COAL STORAGE
PILE TO THE PILE SELECTED FOR SAMPLING
Parameter
u, m/s
P-E index
Size, 10 3 metric tons
s , m2
u3 s°' 35
(P-E index) 2
Emission rate, kg/yr
Representative
pile at U.S.
average conditions
4.5
91
95 a
20,500
0.35
606 ± 648C
Sample
Average
conditions
3.6
103
112 .
41,400
0.18
715
pile
Conditions
at the time
of sampling
1.9
48
112 c
41,400
n i ? + n i ^C
716 ± 657C
Area from derivation described in Appendix C.
Area of coal storage pile from Table A-2 of Appendix A.
^
'At 95% confidence level.
D. ENVIRONMENTAL EFFECTS
Two types of severity are addressed for coal storage piles:
gross particulate and mass coal dust. All other emissions have
been shown to be negligible or were not detected in measurable
quantities. Since the gross particulate emission is 100% coal
dust, the concentrations downwind are the same and the only
difference will be the hazard factor.
1. Ground Level Concentration
The minimum distance from the representative coal pile to the
nearest plant boundary has been determined, as described in
Appendix F, to be 86 m. This is the distance to the point at
A complete derivation and definition of severity are provided
in Appendix H.
17
-------
which the highest concentration would be observed under class C
meteorological conditions (approximate U.S. average). The fol-
lowing formula was used to calculate this concentration which
shall be defined as x (14).
xmax ~ ira a
Y z
where Q = mass emission rate, g/s
a = 0.209 x°-903
crz = 0.113 x°-911
u = 4.5 m/s
This instantaneous ground level concentration at 86 m_is 18 yg/m3,
This must be corrected to the time-averaged maximum, Xmaxr f°r
24 hours as described by Nonhebel (15) so that the mean concen-
tration becomes 6.4 yg/m3.
2. Hazard Factor
The hazard factor, F, is defined as follows for coal dust and is
used to determine source severity:
• TLV (4)
The derivation of F utilizes the TLV corrected from 8-hour to
24-hour exposure with a safety factor of 100 applied to this cal-
culation. The hazard factor-for most coal dust is calculated as
6.7 yg/m3. For gross particulates, F shall be defined as the
24-hour ambient air quality standard of 260 yg/m3.
3. Source Severity
For the representative_coal pile, the maximum severity is deter-
mined from the ratio, Xmax/F* T^e various applicable severities
are given in Table 6. The area affected down to a severity of
0.1 is determined using Figure 4 and Table 6 as described below.
The distance from the coal pile to a coal dust severity of 0.1 is
determined to be 528 m. To this is added the radius of the pile,
80 m, since the expression for Q was derived using the edge of
the pile as a reference. The resulting area of severity involved
is thus 1.2 x 106 m2. From this is subtracted the area of the
plant to represent nonpublic exposure to a severity greater than
0.1. The representative population density is then multiplied
(15) Nonhebel, G. Recommendations on Heights for New Industrial
Chimneys. Journal of the Institute of Fuel, 33:479, 1960.
18
-------
TABLE 6. SOURCE SEVERITY
Distance,
m
86
528
Coal dust
severity
1.0
0.1
Particulate
severity
0.025
-
SEVERITY = 0.1-
Figure 4. Area affected down to a severity of 0.1.
by the resulting area to give population exposed. The population
affected to a severity of 0.1 is 58 persons. The calculation of
the area affected to a severity of 0.1 is shown below.
Area of severity involvement = -rr(528 m + 80 m)2 = 1.2 x 106- m2
Area of plant = 10 (area of pile) = 200,000 m2
Area of affected population = 960,000 m2
Population affected (from Appendix F) = (61 persons/km2) x
(0.96 km)2 = 58 persons.
19
-------
SECTION V
CONTROL TECHNOLOGY
A. STATE OF THE ART
There is no established air pollution control technology for coed
storage piles. Emissions from coal piles are not commonly recog-
nized as a pollution problem. However, the practices of coating
some coal piles with tar derivatives, receiving some coal in a
moist state from cleaning plants, and storing coal outside wher'e
it is subjected to precipitation, all unintentionally control the
entrainment of coal dust.
Coal is coated with tar derivatives to prevent spontaneous com-
bustion of the pile. Oxidation of volatile components of the coal
releases heat which, when concentrated, can cause the coal pile to
spontaneously ignite. Coating of the coal shields it from atmo'-
spheric oxidation. In additon, the tar also causes the coal dust
to adhere to the pile. This increases the resistance of coal dust
to wind entrainment. Conventional spray (60 parts coal tar:40 parts
water) is generally effective for 15 days. However, other emulsions
have been effective for 25 days to 35 days (16). When coal ife
received at the user site from the cleaning plant, it may still
contain excess moisture. Moisture retained within the coal func-
tions in a manner similar to the tar coatings described by causing
the coal dust to adhere to the pile and increase the resistance to
wind entrainment. Storage of coal outdoors exposes it to rain and
snow which also creates this condition.
B. FUTURE CONSIDERATIONS
There is no control technology under consideration for coal Storage
piles. If a need for control were established through an assess1-
ment of the source, initial emphasis would be placed on reduction
of the primary vehicle of dust entrainment, the wind speed. Wind
speed has an effect of ±160% on emission rate of dust particles
with P-E index, bulk density, and surface area values kept constant.
(16) Fuju, K., T. Adachi, Y. Tsukaoa, K. Okuda, and H. Suzuki.
Coal Dust Scattering Preventative. Japanese Patent 73 24,983
(to Nihon Koken Kogyo Co., Ltd.), March 31, 1973. 5 pp.
20
-------
Reduction of wind speed is possible by construction of barriers
around a coal pile and storage of coal in a pit or silo. The
height of such barriers must be greater than the height of the
pile since the wind will tend to project over the barriers onto
the pile. Design criteria for barrier construction must also
enable easy removal and addition of coal to allow this control
method to be economically feasible.
Storage of coal in a pit or silo, where possible, appears to be
the more economical and effective means of wind speed reduction.
Coal stored within a pit or silo is shielded from wind forces,
and is less susceptible to spillage in the area around storage
during loading and unloading. Coal pile spillage is particularly
prone to emission because the greater surface area exposed to
the wind permits faster drying of the coal. The spilled coal
may thus create greater amounts of coal dust than does the coal
pile.
The present practices of coating coal with tar derivatives or
increasing the water content of coal both suppress dust entrain-
ment. However, continued employment of this practice may generate
additional pollutants. When tar is sprayed onto a coal pile,
particulates are emitted from the overspray. The solvent content
of the tar applied is also released upon combustion of the tar
coating on the coal.
Addition of water to the coal also suppresses dust entrainment,
but requires that the coal be dried prior to combustion. Thermal
drying of coal entails a combustion process which may generate
additional pollutants. It is also an expensive process and may
not be economically feasible.
21
-------
SECTION VI
GROWTH AND NATURE OF THE INDUSTRY
A. PRESENT AND EMERGING TECHNOLOGY
Coal storage piles are located outdoors to facilitate the loading
and/or unloading of coal. Outdoor storage also inhibits spontane-
ous combustion caused by atmospheric oxidation. Wind passing over
the coal reduces the concentration of heat within the pile. How-
ever, coatings are necessary to prevent ignition of the coal in
areas with high temperatures and low wind speeds.
It is anticipated that coal will continue to be stored outdoors
in the future. Coal users are expected to locate new plants near
mines to reduce transport costs, assure supplies, and avoid the
stricter environmental standards of more densely populated areas.
The number of coal piles is increasing as the United States uses
more and more coal as an energy source. Coal consumption is
anticipated to increase by 7% per year over the next 10 years (17).
Coal inventories (days of supply) are expected to increase by 3.8%
per year, which will cause an increase in emission rate of 25% by
1978 compared to 1972.
B. COAL STORAGE TRENDS
Usage of coal in the U.S. has followed a curious pattern. Consump-
tion in 1912 was equivalent to consumption in 1970 (18), when coal
accounted for 20% of the total energy input of the United States.
(17) Rieber, M., and R. Halcrow. U.S. Energy and Fuel Demand to
1985. CAC No. 108R (PB 239 343), National Science Foundation,
Washington, D.C., May 1974. 44 pp.
(18) Hottel, H. C., and J. B. Howard. New Energy Technology - Some
Facts and Assessments. MIT Press, Cambridge, Massachusetts,
1971. pp. 3-4.
22
-------
Coal is projected to constitute 30% of energy input, with electric
utilities predicting an increase of 100% to 275% in the use of
coal by 1985 (19).
Utilities will tend to build new facilities near mines, water
supplies, and on large plots of land. Coal storage piles will
thus be located in areas of lower population density and will be
farther from local communities. With more land available,
future coal piles can be expected to be larger to meet the
growing energy needs of the country. Coke plants and industrial
boiler facilities are expected to follow the general trends of
the utilities because they face similar energy situations and
propose similar solutions.
(19) Roach, J. W. U.S. Energy Outlook - Fuels for Electricity.
U.S. Department of the Interior, Washington, D.C., 1973.
p. 4.
23
-------
REFERENCES
1. Keystone Coal Manual, 1973. McGraw-Hill, Inc., New York,
New York, 1973. pp. 304-410.
2. Electric Utility Statistics. Public Power, 32:28-74,
January-February 1974.
3. Steam-Electric Plant Factors/1973 Edition. National Coal
Association, Economics and Statistics Division, Washington,
D.C., December 1973. 110 pp.
4. Coke Producers in the United States in 1972. Mineral
Industry Surveys. U.S. Department of the Interior,
Washington, D.C., November 27, 1973. pp. 2-5.
5. Rumblings from the Mines. Time Magazine, 104(9):35, 1974.
6. Sheridan, E. T. Coke and Coal Chemicals. In: 1972 Minerals
Yearbook, Schreck, A. E. ed. U.S. Department of the Interior,
Washington, D.C., 1972. pp. 427-460.
7. FPC Issues Electric Fuel Consumption Stocks. News Release
No. 20499, Federal Power Commission, Washington, D.C.,
July 22, 1974. 3 pp.
8. A.S.T.M. Standards on Coal and Coke. American Society for
Testing and Materials, Philadelphia, Pennsylvania, September
1948. p. 80.
9. Minerals Yearbook, 1973, Volume I. U.S. Department of the
Interior, Washington, D.C., 1973. pp. 8-36.
10. TLVs® Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment and Intended
Changes for 1973. American Conference of Governmental
Industrial Hygienists, Cincinnati, Ohio, 1973. p. 10.
11. Brown, R., M. Y. Jacobs and H. E. Taylor. A Survey of the
Most Recent Applications of Spark Source Mass Spectrometry.
American Laboratory, 4:34-37, November 1972.
12. Thornthwaite, C. W. The Climates of North America According
to a New Classification. The Geographical Review, 21:633-655,
1931.
24
-------
13. Brown, M. C. Pneumoconiosis dn Bituminous Coal Miners.
Mining Congress Journal, 51:44-48, August 1965.
14. Turner, D. B. Workbook of Atmospheric Dispersion Estimates.
Public Health Service Publication No. 999-AP-26, U.S. Depart-
ment of Health, Education and Welfare, Cincinnati, Ohio,
May 1970. 84 pp.
15, Nonhebel, G. Recommendations on Heights for New Industrial
Chimneys. Journal of the Institute of Fuel, 33:479, 1960.
16. Fuju, K., T. Adachi, Y. Tsukaoa, K. Okuda, and H. Suzuki.
Coal Dust Scattering Preventive. Japan Patent No. 73 24,983
(to Nihon Koken Kogyo Co., Ltd.), March 31, 1973. 5 pp.
17. Rieber, M., and R. Halcrow. U.S. Energy and Fuel Demand to
1985. CAC No. 108R (PB 239 343), National Science Foundation,
Washington, D.C., May 1974. 44 pp.
18T Hottel, H. C., and J. B. Howard. New Energy Technology -
Some Facts and Assessments. MIT Press, Cambridge,
Massachusetts, 1971. pp. 3-4.
19. Roach, J. W. U.S. Energy Outlook - Fuels for Electricity.
U.S. Department of the Interior, Washington, D.C., 1973.
p. 4.
2Q. Singer, J. M., F. B. Cook, and J. Gurmer. Dispersal of Coke
and Rock Dust Deposits. Bureau of Mines RI-7642, U.S. Depart-
ment of the Interior, Pittsburgh, Pennsylvania, 1972. 32 pp.
21. Dawes, J. G. Dispersion of Dust Deposits by Blasts of Air -
Part 1. Research Report No. 36, Ministry of Fuel and Power,
Safety in Mines Research Establishment, Sheffield, England,
May 1952. 69 pp.
22. Woodruff, N. P., and F. H. Siddoway. A Wind Erosion Equation.
Soil Science Proceedings, 29:602-608, May 1952.
23. Bagnold, R. A. The Physics of Blown Sand and Desert Dunes.
Metheun and Co., London, England, 1954. 265 pp.
24T Shafer, H. J. A model Study of the Reduction of Wind Trans-
port of Fine Particles by Aerodynamic Barriers. Presented
at the Fifth Annual Conference on Aviation and Astronautics,
Tel Aviv and Haifa, Israel, 1963. pp. 57-63.
25. Woodruff, N. P., and W. S. Chepil. Sedimentary Character-
istics of Dust Storms II - Visibility and Dust Concentration.
American Journal of Science, 2:104-114, February 1957.
25
-------
26. Cowherd, C., K. Axetell, Jr. ,yand G. Jutze. Development of
Emission Factors for Fugitive Dust Sources. EPA-450/3-74-
037, U.S. Environmental Protection Agency, Research Triangle
Park, North Carolina, June 1974. 172 pp.
27. Jutze, G. A., K. Axetell, and W. Parker. Investigation of
Fugitive Dust - Sources, Emissions, and Controls. EPA
Contract 68-02-0044, Task Order 9, U.S. Environmental Pro-
tection Agency, Research Triangle Park, North Carolina,
May 1973. 61 pp.
28. Annual Report of Research and Technologic Work on Coal.
Bureau of Mines IC-7518, U.S. Department of the Interior,
Washington, D.C., 1949. p. 39.
29. Federal Register, 36(228), November 25, 1971.
30. Martin, D. O., and J. A. Tikvart. A General Atmospheric
Diffusion Model for Estimating the Effects on Air Quality of
One or More Sources. Presented at the 61st Annual Meeting
of the Air Pollution Control Association, St. Paul, Minnesota,
June 23-27, 1968. 18 pp.
31. Tadmor, J., and Y. Gur. Analytical Expressions for the
Vertical and Lateral Dispersion Coefficients in Atmospheric
Diffusion. Atmospheric Environment, 3(6) :688-689 , 1969.
32. Gifford, F. A., Jr. An Outline of Theories of Diffusion in
the Lower Layers of the Atmosphere. In: Meteorology and
Atomic Energy 1968, Chapter 3, D. A. Slade, ed. Publication
No. TID-24190, U.S. Atomic Energy Commission Technical Infor-
mation Center, Oak Ridge, Tennessee, July 1968. p. 113.
33. Code of Federal Regulations, Title 42 - Public Health,
Chapter IV - Environmental Protection Agency, Part 410 -
National Primary and Secondary Ambient Air Quality Standards,
April 28, 1971. 16 pp.
26
-------
APPENDIX A
ANALYSIS OF SAMPLING RESULTS
1. MASS EMISSIONS RATES
Four sampling runs were performed during two different periods,
March and August 1974, at a coal pile site. Sampling equipment
and procedures are described in Appendix D. Since the variabil-
ity of emissions from a single coal pile is greater than the
variations between coal piles (see Appendix B.S.c. for basis)
the results were considered as four separate samples at one coal
pile. The positions of the samplers during March and August are
shown respectively in Figures A-l and A-2. Except for one day,
coal was not being transferred or moved at the pile by bulldozers
during the sampling. This activity would be expected to generate
additional dust that was not due to the storage of coal. In
fact, there was no statistical difference noted. In addition,
the pile selected for sampling was located in a rural, non-
industrialized area in order to avoid any possible interference
from particulates generated at other sources.
The sampler labeled So was positioned upwind of the pile for use
as a reference to the particulate concentration in the atmosphere,
prior to the addition of particulates from the coal pile. Sub-
traction of the concentration level at So from the concentrations
obtained at downwind samples Sj through S^ yielded the concentra-
tion levels due to the emissions from the coal pile. Turner's
atmospheric dispersion equation (14) was then used to calculate
the mass emission rate, Q, from the coal pile:
Q = xyaz™ (A-l)
where x = concentration with no effective plume rise
TT = 3-14
a a = horizontal and vertical dispersion as a
^ function of downwind distance and atmos-
pheric stability
u = mean wind speed
27
-------
WIND DIRECTION
WIND DIRECTION
NJ
00
CRUSHER
HOUSE
S • HIGH-VOLUME SAMPLER LOCATION
HOUSE
S2
S •= HIGH-VOLUME-SAMPLER LOCATION
Figure A-l. March sampling arrangement,
runs Cl and C2.
Figure A-2. August sampling arrangement,
runs CS-3 and CS-5.
-------
a. Mean Emission Factors
The mean emission factor for all the emission rates calculated at
each of the sampler positions is 6.4 mg/kg-yr with a sample stan-
dard deviation of 2.54 (Table A-l). However, the errors associated
with sampling and the use of Equation A-l are combined as shown in
Appendix E to yield an overall standard deviation of 4.3. Since
confidence limits are calculated as follows,
C.L. (8 95% level) = ^- (A-2)
/n
where a = estimated population deviation
t = "Student t" value for n-1 degrees of freedom
@ 95% level
n = number of samples
and a = 4.3
n = 4
t = 3.182
the 95% confidence limits are 6.9 using the emission factor of
6.4 mg/kg-yr.
b. Correlation With Factors Affecting Emissions
Emission rate is calculated from Equation B-18, Appendix B (shown
here for reader convenience):
kuap bsc
Q = (A_3)
(P-E)d
where Q = emission rate, mg/s
k = constant
u = wind speed, m/s
Pb = bulk density, g/cm3
s = surface area
P-E = Thornthwaite1s precipitation-evaporation
index (or P-E index)
In order to apply this equation in determining the extent of
emissions from all 950 coal piles, the most probable exponents
were chosen from similar wind erosion studies performed on coal
piles. In Appendix B, the following exponents for the parameters
of Equation A-3 were presented:
2.7 <^ a <_ 3.0 (wind speed)
2.0 £ b £ 5.9 (bulk density)
c = 0.345 (surface area)
d = 2.0 (P-E index)
29
-------
TABLE A-l. SAMPLING RESULTS - MARCH AND AUGUST 1974
Run number
Date
Cl
3/28/74
C2
3/27/74
CS-3
8/20/74
CS-5
8/22/74
Parameter
Wind speed, m/s
Wind direction, radians
Wind direction range,
radians
Atmospheric stability class
Distance, m A3
" " B
c
" " D
M II T7
" (estimated) F
" (estimated) G
Wet bulb temperature, °C
Dry bulb temperature °C
Barometric pressure, kPa
(mm Hg)
Concentration at Sp. ug/m3
Si
S2
S 3 "
II o II
Dust <10 ym,C %
Moisture in source, %
Emission rate, mg/s
Sample standard devia-
tion, mg/s
Coal stored, 10 3 metric tons
Emission factor, mg/kg-yr
Value
2.7
+1.08
(+61.6)
0.701
(40.2)
B
13.4
37.5
23.8
13.4
34.4
73.2
396
11.9
15.3
99.2
(744)
75
107
127
112
106
100
10
22.4
15.1
89.4
7.91
1.7
+0.633
(+36.3)
0.914
(52.4)
B
28.2
44.8
24.7
26.5
45.1
91.4
122
7.80
11.7
101
(754)
55
60
84
71
55
100
11
12.9
7.10
89.4
4.55
1.5
-0.680
(-39)
0.489
(28)
B
12.8
41.1
15.8
7.6
13.7
122 b
( none )
22.2
29.4
100
(752)
58
63
83
140
89
100
2.3
14.2
11.4
134
3.34
1.5
+0.140
(+8)
1.03
(58.9)
B
4.3
30.5
54.9
3.0
42.7
152
(none)
22.2
29.4
100
(751)
138
341
420
391
262
100
2.2
41.3
13.2
134
9.72
See Figures A-l and A-2.
Elevated 4.6 m.
See Appendix A.3. on particle size distribution.
Average emission factor
Sample standard deviation
Estimated population standard deviation
30
6.38 mg/kg-yr
2.54 mg/kg-yr
2.94 mg/kg-yr
-------
For wind speed, seven different studies were cited (Appendix B)
relating the effect of wind speed to emission rate. Each of these
studies was conducted over specified ranges of wind speed. Coal
storage piles are subjected to mean wind speeds in the range of
1.3 to 6.7 m/s. For this range the effect on emission rate can be
closely approximated by Q a u3. Therefore, u3 can be established
as the relationship representing the effect of wind speed. Two
studies were cited (Appendix B) that relate the effect of bulk
density to emission rate. The first study, by Singer, Cook, and
Grumer (20) , determined the effect on bulk density to be repre-
sented by Q a Pb5*9- However, this study was performed on "free-
flowing" deposits of coal particles. These deposits were composed
of particles between 100 urn and 150 ym in size. In the assessment
of coal storage, from a hazard potential standpoint, only those
particles within the respirable range (less than 7 ym) are of
interest. Therefore, the effect of bulk density represented by
Pb5-9 is discarded. The second study was performed by Dawes (21)
who related bulk density to emission rate as Q a p^,2- In this
study no specific mention of the particle size range under analysis
was cited; however, particles were classified as fine coal dust,
which is the class of particles expected from coal storage emis-
sions. Therefore, the effect of bulk density on emission rate in
this study is represented by pfc2 .
Only one relationship was established for surface area, and this
was obtained via regression analysis of the Singer, Cook, and
Grumer study. Surface area was found to be related to emission
rate by Q a s°- 3If5.
The remaining parameter, Thornthwaite ' s precipitation-evaporation
index, has also been analyzed by various investigators. All
studies indicated that surface moisture, as represented by the
P-E index (which has values for each climatic region) , was approxi-
mated by Q a (P-E)~2. Therefore, Equation A-3, through the use
of these most probable exponents, becomes:
Q = - - (A_4)
(P-E)2
where k is a constant.
(20) Singer, J. M., F. B. Cook, and J. Gurmer. Dispersal of Coke
and Rock Dust Deposits. Bureau of Mines RI-7642, U.S. De-
partment of the Interior, Pittsburgh, Pennsylvania, 1972.
32 pp.
(21) Dawes, J. G. Dispersion of Dust Deposits by Blasts of Air-
Part 1. Research Report No. 36, Ministry of Fuel and Power,
Safety in Mines Research Establishment, Sheffield, England,
May 1952. 69 pp.
31
-------
To obtain the value of the constant without further sampling, the
sampling results in Table A-l were fitted to Equation A-4. The
data (from Table A-l) used in calculating k from Equation A-4 are
listed in Table A-2. The resulting arithmetic mean value of the
constant k from the four runs is 336 with an estimated standard
deviation of 200. Equation A-4 then becomes:
U3p 2S0.345
Q = (336) 2 (A-5)
(P-E)2
where Q is in mg/s.
The error associated with the use of Equation A-5 must be corrected
for the error in determining Q as shown in Appendix E. Therefore,
the estimated population standard deviation becomes 261 and the
95% confidence limits are ±416.a
2. COMPOSITION
Filters were analyzed for major elements by x-ray fluorescence as
described in Appendix D. Results of this analysis are given in
Table A-3. In addition, an infrared analysis was performed for
free silica and it was concluded that less than 1% is present in
the dust samples.
3. PARTICLE SIZE ANALYSIS
The filters were subjected to microscopic evaluation as described
in Appendix D. The results, reported in Table A-4, indicated
few particles greater than 10 ym in size. Because of the low
emission rate only one Brink® sample was obtained. Eighty-eight
percent of the particles from a composite sample taken over the
2 sample days in August were less than 5 ym in size. Based upon
this evidence, it is concluded that essentially all of the
emissions are in the respirable range.
3This assumes that there are four samples taken. In reality
the number lies between two and four for each parameter
evaluated. Four was chosen to represent the best case for
this error.
32
-------
TABLE A-2. DATA FOR CALCULATION OF THE CONSTANT (k)
UJ
Run number
Date
Cl
3/28/74
C2
3/27/74
CS3
8/20/74
CSS
8/22/74
Parameter
Wind speed (u) , m/s
Bulk density (ph) i g/cm3
Quantity stored (Wt) , 10 3
Avg. pile height (h) , m
Surface area (s) , m2
Weeks precipitation, mm
Avg. temperature, °C
P-E index (estimate)
Emission rate (Q) , mg/s
k
2.7
0.8
metric 89.4
t0n 3.6
46,500
17.5
15.3
60.5
22-. 4
159.7
Value
1.7
0.8
89.4
3.6
46,500
17.5
11.7
70.7
12.9
503.1
1.5
0.8
134
4.6
36,400
14.5
29.4
30.8
14.2
166.5
1.5
0.8
134
4.6
36,400
14.5
28.3
31.8
41.3
516.1
Arithmetic mean value of k: 336
Standard deviation (estimate): 200
-------
TABLE A-3.
X-RAY FLUORESCENCE ANALYSIS
OF SAMPLES FROM FILTERS
Element
Sodium
Magnesium
Aluminum
Silicon
Sulfur
Chlorine
Potassium
Copper
Titanium
Chromium
Manganese
Iron
Filter #2
g/m2
0.01
<0.01
a
h
u
0.04
<0.01
<0.01
<0.02
a
a
0.03
Filter 19
g/m2
0.05
<0.01
a
h
u
0.05
<0.01
<0.01
<0.02
_|
N.D.
N.D.
N.D.
<0.01
Filter #11
g/m2
0.01
<0.01
a
h
0.13C
<0.01
<0.01
<0.02
a
a
0.02
Denotes presence possible, but just above background,
probably less than 0.001 g/m2.
Denotes presence likely, but unable to provide an estimate
due to interference of tungsten in line (from x-ray tube)
as well as high counts in this region from the Nucleopore®
filter blank.
^
'No other metal seems to be associated with the increase
in sulfur content. This may suggest presence of organic
sulfur, sulfuric acid, etc.
g/m2.
34
-------
TABLE A-4. PARTICLE SIZE ANALYSES
U)
Size range,
0
1.2
2.4
4.8
9.6
19.2
38.4
to
to
to
to
to
to
to
1.
2.
4.
9.
19.
38.
76.
Sample
Bl
Number of
ym particles
2
4
8
6
2
4
8
Fibers
102
123
34
16
5
3
0
: 0
wt. %a
0.10
0.76
1.67
6.29
15.72
75.46
0
Sample
B2
Number of
Size range, ym particles
0 to 1.2
1.2 to 2.4
2.4 to 4.8
4.8 to 9.6
9.6 to 19.2
19.2 to 38.4
Fibers
93
106
31
14
4
0
: 0
wt. %a
0.48
3.20
7.48
27.04
61.80
0
These conversions of particle number to weight percent are estimates
only and assume spherical particles of uniform density.
-------
APPENDIX B
FACTORS AFFECTING COAL STORAGE EMISSIONS
1. INFORMATION
In this source assessment a study was made to determine the
factors that affect emissions and/or entrainment rates for open
coal storage piles. Unfortunately, no data directly applicable
to this pollutant source were available. However, data from in-
vestigations of somewhat similar problems were readily available.
The bulk of the empirical relationships expressed in this study
were derived from the results of wind tunnel experimentation
conducted by the Pittsburgh Mining and Safety Research Center,
Pittsburgh, Pennsylvania (20). This study was performed to
determine minimum air velocities and entrainment rates for 66al
bed and rock dust dispersion under conditions that simulate disper-
sion from surfaces in coal mines where airflows are induced by
weak explosions. The investigation analyzed the effect of a
number of factors also believed to influence wind erosion of open
coal storage piles. These variables are:
• Wind velocity at the midheight of the coal dust
bed, UL, m/s
• Bulk density of the coal dust bed, pj-,, g/cm3
• Surface area of the coal dust bed, s, cm2
• Leading angle at the base of the coal dust bed,
AL, degree (free-flowing deposits only)
• Volume of the coal dust bed, V, cm3
• Height of the coal dust bed, H, cm
• Width of the coal dust bed, W, cm (cohesive
deposits only)
Data presented were of a rather limited nature, encompassing art
extremely narrow range of values for each variable. Dust bed
geometry data were particularly limited in all dimensional
aspects. Dust bed composition was limited to two principal
classifications:
36
-------
• Free-flowing coal dust beds, limited to
particles 100 ym to 150 ym in diameter
• Cohesive coal dust beds, containing
particles 6 ym to 80 ym in diameter
The two types of dust beds differed not only in particle size
distribution, but also in their respective modes of dispersion.
At the high wind velocities (considered 10 to 60 mph), free-
flowing deposits were entrained by single particle detachment
while cohesive deposits dispersed by clump removal.
Since open coal storage piles are rarely subjected to wind speeds
capable of initiating dispersion by clump removal, empirical re-
lationships derived from experimentation on free-flowing deposits
are considered more applicable to open coal storage.
2. DERIVATION OF PARAMETERS
a. Wind Velocity, UT, u „ . (m/s)
j_j ave
Relationships between entrainment and wind velocity have already
been derived (21):
En - UL2>1 °r En • Uave2-7 (B
where E = entrainment rate, g/s of free-flowing
n dust beds
u_ = air velocity in the wind tunnel at the
midheight of the dust bed, m/s
u = mean air velocity in the wind tunnel, m/s
ave
37
-------
Other investigators have derived similar relationships:
Entrainment Wind speed range,
rate _ _ m/s _ Reference
ESQ - v3 1.3 to 6.7 22
ESA " Fu3 >4'5 23
ESA ' u2'7 4'5 to 8'9 2°
En <* u3 >6'7 21
Ep <* vF9 0 to 0.9 24
Es « v9 <1.3 25
EA « v3 1.3 to 8.9 26
where all E terms ar& symbols for entrainment rate and wind
velocity is expressed as Fu, u, or v.
b. Bulk density, p., (g/cm3)
Relationships between entrainment rate and bulk density have
already been derived (20) .
E « p,5-9 (100 urn to 150 vim particle diameter) (B-2)
(22) Woodruff, N. P., and F. H. Siddoway. A Wind Erosion Equation,
Soil Science Proceedings, 29:602-608, May 1952.
(23) Bagnold, R. A. The Physics of Blown Sand and Desert Dunes.
Metheun and Co., London, England, 1954. 265 pp.
(24) Shafer, H. J. A Model Study of the Reduction of Wind
Transport of Fine Particles by Aerodynamic Barriers.
Presented at the Fifth Annual Conference on Aviation and
Astronautics, Tel Aviv and Haifa, Israel, 1963. pp. 57-63.
(25) Woodruff, N. P., and W. S. Chepil. Sedimentary
Characteristics of Dust Storms II - Visibility and Dust
Concentration. American Journal of Science, 2:104^114,
February 1957.
(26) Cowherd, C., K. Axetell, Jr., and G. Jutze. Development of
Emission Factors for Fugitive Dust Sources. EPA-450/3-74-
037, U.S. Environmental Protection Agency, Research Triangle
Park, North Carolina, June 1974. 172 pp.
38
-------
Bulk density is an extremely important entrainment factor for
free-flowing deposits because, at some critical wind velocity,
dispersion may change from single particle to clump detachment.
Dawes (21) reports an additional relationship for the effect of
density on fine coal dust:
E " Pb2 (particle size range unknown) (B-3)
The relationship is dependent upon particle size and thus bulk
density will reflect fineness of the coal dust.
c. Surface Area, s, (cm2)
Due to a wide scattering of data, the investigators (20) derived
no relationship between entrainment rate and dust bed surface area
for free-flowing deposits. However, by employing a regression
analysis on their data, the following approximate relationship was
determined for free-flowing dust beds:
E - s°-3tt5 (B-4)
n
d. Other Wind Tunnel Study Parameters
The parameters listed below were studied in a wind tunnel and no
relationship was found (20) . A regression analysis shows that
their effect on emissions, if any, is not as pronounced as those
of the other parameters. The height, volume, and possibly the
leading angle may be expressed as functions of surface area:
Function Relationship
Angle, deg. En « AL°-llf9
Volume, cm En <* v°-25
Height, cm En * R°-228
Width, cm E <= w°-386
e. Nonwind Tunnel Study Parameters
A number of factors thought to influence open coal storage emis
sions were not considered in the aforementioned investigation.
These factors include:
• Length of the coal pile along the prevailing
wind direction (22)
39
-------
Particle-size distribution (22) (effects inde-
pendent of bulk density)9
• Surface moisture (12, 22, 26, 27)
They were assessed in other studies, although the relationships
derived were based on wind erosion of soil and windblown emissions
from tailings and aggregate storage piles. The quantitative as-
pects of these factors relative to entrainment rates are discussed
below-
(1) Length—
ESQ - f (L1 - b)n (Reference 22) (B-5)
where L1 = length of exposed field areas
Th,is relationship may not be applicable to open coal storage due
to the relatively small values for L1 involved and the geometric
differences between fields and storage piles. This function
attempts to relate "avalanching" which generally is not precipi-
tated in less than several hundred yards. Coal piles are usually
not long enough for this to occur.
(2) Particle Size Distribution—
E a i (Reference 22) (B-6)
oO
where I = the soil erodibility index for different soil fractions
This relationship may not be applicable to open coal storage in
its present form due to physical and chemical dissimilarities be-
tween coal particles and soil fractions. Since this assessment
is primarily concerned with respirable dust (<7 ym), the primary
effect is described by bulk density and particle size is not
deemed of further importance in the comparison of one coal pile
to another.
(3) Moisture—
ESO " S^ (Reference 22) (B-7)
ESO " (p-E)2 (References 12, 22) (B-8)
where M = surface moisture
aEntrainment rate is a function of particle size and a function
of bulk density; these are treated as two independent
variables.
40
-------
Pf-E, which refers to Thornthwaite' s precipitation-evaporation
index, is only an approximation of surface soil moisture and is
used because values for M are not readily available.
ESO * (P-E)I (B'9)
(Here, E refers to tailings piles rather than soil.)
EA « 1 f (Reference 26) (B-10)
Of all these factors, surface moisture is most important since
it will tend to suppress dust. The evaporation of moisture will
likewise provide thermal currents which enhance dust formation.
Th,is action is similar to that occurring in soils and thus the
P-p index as described by Thornthwaite, is a logical representa-
tion for surface moisture.
The empirical relationships shown here are for the most part very
general approximations based on a variety of investigations. They
may not be directly representative of conditions encountered in
open coal storage. Thus, the accuracy and applicability of the
results in the composite equation presented in the next section
should be viewed with this in mind. Although quantitative
relationships derived in this analysis may not be directly appli-
cable to open coal storage, some conclusions concerning the
relative importance of the various factors to coal dust entrain-
ment are drawn by sensitivity analysis in Section 3.c. of this
appendix.
3. COMPOSITE EQUATION
a. Development
Based on the relationships presented in Section 2 of this
appendix, the following quantitative expressions are judged to
be most applicable to open coal storage:
Q oc U2. 7-3.0 (B-ll)
where u = wind velocity
Q - Pb2 (B-12)
where p. = bulk density
Jutze, G. A., K. Axetell, and W. Parker. Investigation of
Fugitive Dust - Sources, Emissions, and Controls. EPA
Contract 68-02-0044, Task 9, U.S. Environmental Protection
Agency, Research Triangle Park, North Carolina, May 1973.
61 pp.
41
-------
H0-23
where H = height
Q
(B-13)
(B-14)
where AL = leading angle in the prevailing wind direction
Q a v°-25 (B-15)
where V = volume
where s = surface area
Q oc S0 . 35
(P-E)~2
(B-16)
(B-17)
Obviously, wind velocity, bulk density, and surface moisture (P-E
index) are the most important factors influencing the open coal
storage entrainment/emission rate, Q.
The remaining variables: height, leading angle in the prevailing
wind direction, volume, and surface area, describe coal pile
geometry. Length and width, which also describe pile geometry,
are deleted because they could not be adequately related to open
storage entrainment; that is, they are not describable in a manner
that would increase the usefulness of a quantitative expression.
Judging by the similarity of the exponents attached to H, AL, V,
and s, the factors determing coal pile geometry are all inter-
related. For this reason, a single variable, s, was chosen to
describe pile geometry. Considering the small magnitude of the
exponents attached to s, H, A , and V, entrainment rate is only
slightly dependent on pile geometry. Based on these criteria,
open coal storage entrainment is determined by the following
expression:
Q = k
(P-E)2
where the exponents are expected to be in the range:
2.7 < a < 3.0
2 < b < 6
0.15 < c < 0.35
(B-18)
42
-------
b. Comparison with Wind Erosion
Both Woodruff (22) and Chepil (25) have described the process of
wind erosion and the factors which affect soil erosion. The
Woodruff equation is of the form:
E = f(I', C1, K1, L1, V) (B-19)
where I1 = soil and knoll erodibility index for different soil
fractions
C1 = local wind erosion climatic factor
K1 = surface roughness
L" = unsheltered distance across the field along the
prevailing wind direction
V = vegetative cover
.E = potential average annual soil loss
This may be reduced to Equation B-20 by defining the variables
through their appropriate algorithms. Thus:
E = I«C»K-L«V (B-20)
where I = f(I') (B-21)
C = f(C') (B-22)
K = f(K1) (B-23)
V = f (V) (B-24)
L = f(L', I«K, I-OK) (B-25)
This form of equation is the same as the process described by
Woodruff and Siddoway (Equation B-19). Equations B-21, B-22,
B-23, and B-24 are very direct relationships based completely
upon independent variables which are not as complex for coal
storage piles as they are for wind erosion.
Parameter I can be related to the particle size distribution of
the material being eroded. Furthermore, this particle size dis-
tribution can be related to the bulk density of the coal in a
direct manner. Thus, for a size distribution, SD,
I = k!(SD)a = k2Pbb (B-26)
where SD = k3pbb//a (B-27)
or SD a p° (B-28)
43
-------
Equation B-26 gives a relationship of the basic credibility for
the source. As, the particle size distribution range is reduced
(from 840 i_im to 7 ym), a smaller variation in I would be expected
as one proceeds from site to site of a source. This has been
borne out in t^e wind tunnel studies already completed on coal
(20, 23).
The parameter £ can be related wholly to the ratio of wind speed
to P-E index:
C = k - (B-29)
The parameters K and V are related to ridge roughness and vegeta-
tion cover and for coal storage piles these can be equated to
one since neither one is applicable.
The length of the unsheltered field is the only complex variable
which need be addressed. In Woodruff's system, the effect can be
described by Equations B-30, B-31 and B-32. Woodruff used E2
equal to the product of I and K, so that E2 may be set equal to, I
in these expressions.
L = 1.0 (B-30)
when E2 > 37,317 (L1)0-751 (B-31)
Otherwise L = k5 (L')e E2g (B-32)
where L1 = distance across field
Combining Equation B-20, B-26, B-29 and B-30, the overall expres-
sion for E can be described as:
u3 pbb
E = k2 kt, (p_E)2 (B-33)
Since Q is mass emission per unit time and E is mass erosion per
area per unit time, Equation B-33 can be expressed;
Q = Es (B-34)
3 *>
XI Pi S
Q = k6 -fl^gpr (B-35)
where k6 = k2«kit
s = area of pile
44
-------
If Equation B-32 is used instead of Equation B-30, then the over-
all expression for E becomes Equation B-37 since I may be sub-
stituted for E2 in Equation B-32 to yield Equation B-36. However,
this can be further reduced to Equation B-38 with Equation B-26.
L = k5{L')e!g (3-36)
uVb(L')eig
E = k2kkk5 - 2 - (B-37)
(P-E)2
a
E = kgk,k5 — - (B-38)
(P-E)2
For this study, the length of the exposed field, L' , used by
Woodruff can be equated to a parameter of the coal pile. Assuming
that coal piles are square with an area of s, Equation B-39 can be
combined with Equation B-38 to give the net relationship shown in
Equation B-40.
s = (L1)2 (B-39)
(B-40)
" ~7 (p-EJ-Z
where m = b + bg (B-41)
k7 = k£ k^ks (B-42)
Substituting for E (from Equation B-40) into Equation B-34, the
overall relationship is obtained:
Q = k7 (p,E)2 (B-43)
where n = | + 1 (B-44)
Thus, either Equation B-35 or B-43 would describe the windblown
emissions for coal piles depending upon the size of the pile.
These equations compare favorably with the form of Equation B-18
and confirm the validity of the form of emission expression given.
By combining Equations B~31, B-39 and B-26, Equation B-35 may be
considered valid when:
45
-------
Yb
Pb >li£TTi (s)°-37M (B-45)
51
otherwise the expression developed in Equation B-43 would be
valid. Thus, for large coal storage piles, the expression for Q
in Equation B-43 could be most appropriate. A regression of the
expression in Equation B-18 with sampling data would resolve the
correct exponents.
c. Sensitivity Analysis
The factors which affect coal storage pile emissions can be con-
sidered as bounded variables. Thus the emission equation will like
wise be a bounded expression. . It is desired to express all results
ultimately on an annual basis so that all factors should be annual
mean values. The range of each of these factors is as follows:
1.3 < u < 6.7 m/s average =4.5 m/s
0.64 < p, < 0.86 g/m3 average =0.80 g/m3
7 < P-E < 179 average =91
4.0 < s < 5.3 x 10 5 m2 average = 4.0 x lO1* m2
By selecting exponents for Equation B-18 the effect of each vari-
able can be determined. A value for the expression is determined
from average values to serve as a reference. The results of the
sensitivity analysis are given in Table B-l. It is apparent that
P-E index is by far the most important factor affecting the dis-
tribution of emissions from coal piles. The least effect is from
density. The omission of density from the expression would result
in a possible variation in emissions of as much as ±65%. Leaving
P-E index out gives an unreal variation of ±8,500. The factors
which affect the emissions are (in decending order of importance)
P-E index, wind speed, area, and density.
Since the P-E index affects the emissions the greatest, emissions
can vary greatly with ambient temperature and precipitation. With-
out the effect of P-E index, emissions could vary by 350%; however,
the normal variation in precipitation can exceed this in most parts
of the U.S. Coupled with this is the normal fluctuation in ambient
temperature at a specific site. Thus the variation in emission
rate of a coal pile is greater at a specific site than it normally
would be from one site to another.
4 . SUMMARY
Equation B-18 is used in conjunction with the sampling results in
Appendix A (Table A-2) to determine an analytical expression or
the emission rate from coal storage piles (Equation A-5) which is
reproduced as follows:
46
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TABLE B-l. SENSITIVITY ANALYSIS OF ENTRAINMENT/EMISSION RATES CALCULATED
USING EQUATION B-183 WITH AVERAGE, MINIMUM, AND MAXIMUM VALUES
FOR WIND VELOCITY, BULK DENSITY, P-E INDEX, AND SURFACE AREA
Entrainment/emission rate (Q)
(Calculated using average, minimum or maximum values for independent variables as indicated)
Pxnonents8 Using average
Exponents -,_•,„„_ f~r -.ii
a b c variables"
3.0 2.0 0.35 97
3.0 6.0 0.35 40
2.7 2.0 0.35 61
3.0 2.0 0.15 12
aEquation B-18:
kua(pb) sc
Q (P-E) 2
where Q = entrainment/
emission rate.
Wind speed, m/s Bulk density, g/cm3
u = 1. 3 u = 6. 7 p, =
2.3 319 62
Ac = 3.3
0.95 131 10.
A = 3.. 2
2.2 180 39
A = 2.9
0.28 38 7.
A = 3.1
0.64 pb = 0.86
112
A = 0.52
4 62
A = 1.3
71
A = 0.82
4 13.4
A - 0.50
Average values for
independent
U— A C
Pb = 0.80
s = 4.0
variables :
g/m3
x 10" ra2
P-E index Surface area, m2
P-E = 7 P-E = 179 s = 4.0 s=5.3x!05
16,300 25 3.8 239
A = 170 A = 2.4
6,680 10.2 1.6 98
A = 170 A = 2.4
10,400 15.9 2.4 152
A = 170 A = 2.4
1,960 3.0 5.7 17
A = 160 A = 0.94
A is calculated from:
Tnax ~ Tnin
Q
where Qmax = emission rate calculated
mg/s
k = constant = 336
u = wind velocity, m/s
pb = bulk density, g/cm3
s = surface area, m2
a,b,c = exponents
P-E = Precipitation-
Evaporation Index
P-E = 91
independent variable
= emission rate calculated
using minimum value for
independent variable
Qa = emission rate calculated
9 using average values for
all independent variables
-------
,,3n 2 0.345
Pb s
Q = 336 — (B-46)
(P-E)2
This expression can be used to predict emissions within 124%, 95%
of the time over limited ranges of u, p]-,, s and (P-E) as described
in Appendix A. Since this expression has limited use and it was
not desired to pursue its development into a more universal equa-
tion, only its implications on the factors affecting emissions are
used in this document. For relating emissions to these parameters
an overall emission factor is used.
48
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APPENDIX C
DERIVATION OF SURFACE AREA FROM HEIGHT OF COAL PILES
The surface area of a coal storage pile is primarily a function of
the amount of coal stored. Functionally, this is determined as
follows:
T
s =
where s = surface area, cm2
T = weight of coal stored, g
p, = bulk density, g/cm3
H i= pile height, cm
In the mass emission rate equation developed iri Appendix B, s is
Used to relate all geometric parameters of coal piles. This
assumes a dependence dn the height of the coal pile. It has been
stated that coal is generally piled 4.3 m to 8.8 m (14 ft to
29 ft) high, averaging about 5.8 m (19 ft) (28). A random survey
was conducted of 12 coal piles. The results, given in Table C-l,
indicate a range of 2.4 m to 11.3 m (8 ft to 37 ft), with the
average being 6.0 m (19.6 ft) which is within 3% of the reported
data. For converting weight to surface area, a constant height of
5.8 m (19 ft) is used.
Pile shape, and thus height, is generally dependent on the weight
of coal stored. The small piles usually associated With smaller
boilers or coke plants are generally conical in form to facilitate
handling. Conical storage does not require the use of auxiliary
equipment such as bulldozers. In addition, the smaller plants are
llsually nearer to population centers, and space is at a premium.
(28) Annual Report of Research and Technologic Work on Coal.
Bureau of Mines IC-7518, U.S. Department of the Interior,
Washington, D.C., 1949. p. 39.
49
-------
TABLE C-l. HEIGHT OF COAL PILES
Site
m
Height
ft
1
2
3
4
5
6
7
8
9
10
11
12
x = 6.0 m or 19.6 ft
The error in predicting the supply stored varies with the facility
at which the coal is stored. For the three types of facilities
considered, the errors are:
7.6
6.1
4.3
6.1
9.1
3.0
11
8.2
3.6
6.1
3.6
2.4
25
20
14
20
30
10
37
27
12
20
12
8
Coke plants
Boiler plants
Utilities
23 days ± 43%
39 days ± 59%
93 days ± 74%
Based on the number of each type of facility, the overall weighted
error introduced due to normal variations of tonnage stored is
61%. The use of 800 kg/m3 (50 lb/ft3) for the density of coal
introduces an additional error of 10%. By considering the coal
pile height constant at 5.8 m (19 ft), the error is 26%. Thus the
error introduced by the use of constant values for pj-, and H
increases the error in the estimate of s by 36%. The overall error
is 97% which is within the allowable limits for use in the emission
rate equation (Appendix B).
50
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APPENDIX D
SAMPLING EQUIPMENT AND PROCEDURES
1. HIGH-VOLUME SAMPLING METHODS AND EQUIPMENT
To perform the sampling required, high-volume samplers9 were posi-
tioned around the coal pile as shown in Figure A-l and A-2. The
arrangement in Figure A-l permitted correlation with horizontal
dispersion and sampler S3 would illustrate downwind power law
decay. This arrangement was altered for later sampling to Figure
A-2 when the observed concentrations were not sufficient to make
these correlations. Nucleopore® membrane filters were used for
sample collection due to their relatively low tare weight (500 mg)
and high flow capacity (36 1/min-cm2, 93.3 kPa pressure drop) in
comparison with similar filters. The lower tare weight and higher
flow capacity enabled the particulate collected to comprise a
higher percentage of tare weight and thus provide results that
were within the measurable range., After particulate matter on the
filters was weighed (subtracting the tare weight), the mass con-
centration of suspended particulate was computed from the volume
of air sampled. The concentration of particulate collected at
reference sampler S0 was subtracted from the concentration of the
other samplers (S^ S2, S3, and S^) to yield the particulate con-
centration due to the coal pile emissions. The mass emission rate
was determined using Turner's equation for a ground level source
with no effective plume rise (16) as shown in Appendix A.
A.Brink® impactor was used to determine the size distribution of
the particles emitted. This unit has a relatively low sampling
rate of <5 x 10~5 m3/s (£0.1 acfm) and small tare weight ( = 13 mg)
in comparison with similar units. The percent of particles smaller
than 5 ym captured by the Brink unit was used to estimate the
weight of respirable particulates collected by the high volume
samplers. Because of the low mass emission rate only one compo-
site sample (two sample days) was collected.
A meteorological station was employed to monitor wind speed,
direction, and temperature. The median wind speed over a 1-minute
time lapse, was recorded at 15-minute intervals. The mean wind
speed was then calculated from the arithmetic average of the
General Metals Works, Inc., Cleves, Ohio.
51
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15-minute readings over the entire run. Wind direction was
similarly recorded every 15 minutes. If the direction varied by
more than ± 0.78 rad (± 45°) from the centerline for two consecutive
recordings, then either: 1) sampling was terminated when the runs
had proceeded for more than 4 hours, or 2) sampling was continued
when the wind direction returned to within ± 0.78 rad (± 45°) if the
run had proceeded for less than 4 hours. The standard of 4 hours
was chosen since it is approximately the minimum time required for
particulate collection to equal about 20% of the tare weight of the
filter, the target minimum weight of collected particulate that can
be measured. The minimum desired mass of particulate collected is
a weight equal to one-half the tare weight of the filters. A
sampling run of 8 hours was chosen in an attempt to achieve this
goal. The ± 0.78 rad (± 45°) (from centerline) fluctuation of wind
direction between two consecutive runs was chosen since greater
variations have resulted in poor particulate collection. Quite
often, changes of this magnitude result in frontal movement and
rain or wind storms.
Temperature values were read at the meteorological station within
the accuracy of the instrument, which was ± 1.1°C (± 2°F), and
averaged for the week of sampling. Precipitation levels for the
week were obtained from the nearest weather bureau in the area.
Weekly values are utilized to determine the possible effect of
these parameters prior to sampling. These effects are then
accounted for by calculating a psuedo P-E index for the year from
these weekly values. (A yearly index based upon weekly values,
assumes that sample history for every week is identical to
each and every other week, that is, the rain and temperature
patterns are identical, for the year, to the selected weeks.)
To determine the quantity of coal stored, the present inventory
level at the plant was obtained from company records. Bulk den-
sity was obtained directly from tables relating density to the
class of coal stored or from proximate analysis (supplied by
the company).
2. FILTER ANALYSIS PROCEDURES
a. Concentrations
High volume samplers are used to collect the particulate matter.
Weights are determined to the nearest milligram, airflow rates to
the nearest 5 x 10~3 m3/s, and time to the nearest 5 minutes.
Mass concentrations are reported to the nearest yg/rn3. At an
average mass concentration of 128 yg/m3, the standard deviation
is 5.12.
Prior to sampling the unit was calibrated by use of a calibrating
orifice assembly and water manometer. (These calibration units
52
-------
are adjusted with a positive displacement meter.) A chart was
then drawn of airflow versus static pressure. After the orifice
was attached to the unit the airflow was varied by the addition of
perforated plates across the airflow stream. A calibration curve
was then plotted relating airflow readings to actual flow in non-
metric units.
Prior to sampling, each filter was inspected for imperfections,
desiccated in a balance room, and weighed to the nearest milligram
in a weighing chamber. The tare weight was then recorded and the
filter holder labeled. Once sampling was completed, the volume
was determined from the initial and final airflow readings. (These
readings are converted to m/min through an appropriate calibration
curve.) The volume of air sampled was determined as follows:
Q-i + Qf) * t
*
va
where v = air volume sampled, m3
Q. = initial airflow rate, m3/min
Q.p = final airflow rate, m3/min
t = sampling time, min
s
Once the volume was determined and the final weight of the fil-
ters established (by the procedure previously mentioned) , the mass
concentration of particulates was determined by:
- W.)
a
x 106
(D-2)
where X = mass concentration of particulate, yg/m3
Wi = initial (tare) weight of filter, g
Wf = final weight of filter, g
va = volume of air sampled, m3
10 6 = conversion of g to pg
b. Composition
After the filter is weighed, one portion is selected for micros-
copy examination and another for composition analysis. X-ray
fluorescence was chosen to give a semiquantitative determination
of particulate composition.
(1) The Principle of X-Ray Fluorescence (XRF) Analysis —
XRF analysis is based on measuring individual, characteristic
x-rays for each element in a sample by energy dispersive tech-
niques. These secondary fluorescent x-rays are generated by
irradiating the specimen with a primary source of x-rays using
either a tungsten or rhodium target x-r,ay tube. All secondary
x-rays are detected simultaneously with a silicon semiconductor
detector. By using suitable amplifiers and an x-ray energy
distribution analyzer, the characteristic x-rays for each element
53
-------
are electronically separated based on their energy and are dis-
played in either a spectral or alphanumeric mode via video monitor
The data are also stored in a computer memory for additional data
improvement or for on-line computerized data reduction and presen-
tation in a teletype print-out.
An on-line computer is used for data reduction. Computer programs
enable manipulation of spectral data to eliminate interfering
lines, to integrate peaks, to subtract backgrounds, to correct for
interelement and matrix effects, and to provide a variety of quan-
titative conversion equations to reduce raw counts to elemental
concentration.
(2) Applicability of XRF—
The XRF technique is applicable to qualitative and quantitative
elemental analyses (sodium to uranium) for solids (whole sections
or powdered) and liquids (including solids in solution). In the
specific case of particulate collected on filters, the direct
measurement of these specimens can provide a detection limit of
<0.2 yg/cm2 with sample loadings of 1.2 yg/cm2. The detection
limit is influenced by many factors including energy of the x-rays
being emitted by the elements, matrix, counting times, excitation
source, and sample chamber atmosphere. For particulate on filter
paper with a loading of 1.2 yg/cm2 and with a rhodium excitation
source, the following detection levels can be attained:
Detection level,
Element yg/cm2
P 0.20
S 0.11
K 0.15
Ca 0.06
Cr 0.06
Fe 0.05
Ni 0.05
Cu 0.05
Zn 0.04
As 0.04
Br 0.07
Cd 0.13
Ba 0.13
Hg 0.08
Pb 0.07
(3) XRF Apparatus—
The analytical system used in these measurements is composed of
an EDAX International Inc-. Mark II Basic EDAM System, EDAX Model
707A Super Analyzing Unit, a Data General Corp. 12 K Computer
(Nova 1220) , and a Teletype 33TC. Either a rhodium or tungsten
target x-ray tube is available. The system can be operated with
54
-------
the sample maintained in vacuum or in a helium purged atmosphere.
Samples up to 76 mm (3 in.) in diameter can be analyzed.
(4) Calibration of XRF Equipment--
Quantitative analysis with the x-ray technique is based on using
(a) reference standards of known concentrations of the desired
elements in a matrix similar to that of the unknown specimens, or
(b) mathematical corrections through computer programs to correct
for interelement and matrix effects.
If a range of standards is avilable, it is possible to establish
a working curve for each element which is a plot of concentrations
in micrograms (or pg/cm2) vs. the intensity of the x-rays charac-
teristic of each element. If the range of standards is not avail-
able, the ratio of the intensity of the peak of unknown concen-
tration of an element to the intensity of the peak of a known
concentration of that same element will provide a reliable semi-
quantitative analysis (± £50% of the amount present).
Standards are prepared by precipitation or deposition of NBS
Standard Research Materials, metal oxides or salts, or portions
of "loose" particulate collected during long-term sampling. In
the latter case, emission spectrographic analysis of this material
serves to provide the needed compositional information for pre-
paring standards. Several deposition procedures are used for
preparing semiquantitative standards including the filtration of
particulate suspended in carbon tetrachloride and the filtrations
of particulate suspended in gas matrix or deposited from solution.
Other semiquantitative measurements of particulate collected on
filters are made by correlating the x-ray fluorescence responses
of test samples with emission spectrographic analyses of ash for
one or more of the test specimens in a set. This correlation
serves to provide a semiquantitative means of rapidly analyzing
large numbers of filters by XRF without going through an ashing
step, which is required for emission spectrographic analyses of
filters with low loadings.
(5) Procedure for XRF Analysis—
Based on the type of sample matrix and the elements being meas-
ured, the excitation source and the x-ray excitation voltage are
selected. Either a helium flush or vacuum is applied to the
sample chamber, and proper selection of the energy range is made
to optimize response. The filter specimen is analyzed by counting
the secondary x-rays for 100 seconds to 2,000 seconds depending on
quantity of material on the filter.
The spectral data are manipulated by computer software to smooth
the statistical channel-to-channel fluctuations in the spectrum,
subtract background or spectra characteristic of residual trace
elements in the filter, strip a series of peaks characteristic
of specific elements, and obtain quantitative or semiquantitative
55
-------
data by comparing the spectral intensity of the test specimen
with the known values of the standard samples.
(6) Calculations—
The computer provides the resulting values (quantitative or semi-
quantitative) in yg/cm2 or comparable notation as programmed.
3. GAS SAMPLE ANALYSIS
a. Collection Procedure
Several grab samples were collected for analysis of total hydro-
carbons, methane, carbon monoxide and total sulfur. A 250-ml
Pyrex flask with a stopcock on each end was cleaned and filled
with dry nitrogen. The top of one of the stopcocks was fitted
with a rubber bulb and one-way flow valve so as to pull a vacuum
on the Pyrex flask. The other stopcock was covered with cotton
and inserted about 150 mm into the coal pile. Both stopcocks
were then opened and about 1 liter of gas was pulled through the
flask. The stopcocks were closed and the flask returned to the
laboratory for analysis.
b. Analysis of Total Hydrocarbons, Methane and Carbon Monoxide
(1) Principle and Applicability—
The method used in this analysis is a semicontinuous technique
for measuring total hydrocarbons, methane and carbon monoxide in
ambient air (29) . Minor modification of electronics enables
measurements from 0.1 ppm up to 2%.
(a) Principle—Measured volumes of gas samples are delivered to
a hydrogen flame ionization detector to measure total hydrocarbon
content. An aliquot of the same gas sample is introduced into a
stripper column which removes water, carbon dioxide, and hydro-
carbons other than methane. Methane and carbon monoxide are
passed quantitatively to a gas chromatographic column where they
are separated. The methane is eluted first and is passed un-
changed through a catalytic (nickel) reduction tube into the
flame ionization detector. The carbon monoxide is eluted into
the catalytic reduction tube where it is reduced to methane
before passing through the flame ionization detector. Between
analyses, the stripper column is backflushed to prepare it for
the subsequent analysis. Hydrocarbon concentrations corrected
for methane are determined by subtracting the methane value from
the total hydrocarbon value.
(b) Applicability—The method is applicable to the semicontinuous
measurement of hydrocarbons, methane, and carbon monoxide in
ambient air and in grab samples from emission sources.
(29) Federal Register, 36(228), November 25, 1971,
56
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(2) Apparatus—
The instrument was designed and assembled by Monsanto Research
Corporation personnel using design criteria that met Federal
EPA specifications. Another model in this series was tested and
found acceptable by the Federal EPA at Research Triangle Park,
North Carolina.
(3) Calibration—
The instrument is calibrated with a series of methane and carbon
monoxide standards prepared in synthetic air by Scott Research
Labs. The values of instrument response vs. concentration of the
standard gas samples are plotted.
(4) Procedure—
The sample is introduced into the system under the same conditions
of pressure and flow rates as are used in calibration. Mathemat-
ical corrections can be made as needed for sample pressure differ-
ences (particularly when analyzing glass gas sampling tubes) by
incorporating suitable pressure-volume relationships based on the
ideal gas law.
(5) Calculations—
Concentrations of total hydrocarbons (as methane equivalents),
methane, and carbon monoxide are determined directly from the
calibration curves. No calculations are necessary, unless sample-
standard pressure differences require corrections [see (4) above].
The concentrations of hydrocarbons corrected for methane is
obtained by subtracting the methane concentrations from the total
hydrocarbon concentration (as CH4).
c. Analysis of Sulfur
Several methods for sulfur analysis were attempted. Flame photo-
metric and gas chromatographic analyses did not indicate substan-
tial levels of any sulfur compounds even upon heating of the sample
flask. The lower level of detection was 0.1 ppm. A variety of
other procedures was also briefly investigated.
4. SAMPLING GUIDELINES AND DATA SHEETS
Guidelines and sampling data sheets used by field sampling teams
for open sources are shown in Tables D-l, D-2, and D-3, and
Figure D-l.
57
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TABLE D-l. OPEN SOURCES SAMPLING GUIDELINES
1. Determine predicted wind direction and speed
a. U.S. Weather Bureau
b. Field estimate
2. Determine atmospheric stability class expected - see Table
on worksheet, (Figure D-l).
3. Locate positions of samplers around source. Use guidelines
for downwind distance (Table D-2).
4. Place upwind sampler (background) and start sampling.
5. Place wind instrument and downwind samplers for source
monitoring.
6. Wind direction and speed monitored every 15 minutes,
stability class every 2-3 hours, note time sampler flow
rates were checked at first 1/2 hour and then every 1-1/2
hours. If wind direction is off centerline by more than
0.78 rad (45°) in two consecutive readings, stop samplers
until direction returns within 0.78 rad (45°) for 15
minutes.
7. Sampling completed in minimum sampling time determined by
project leader.
58
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TABLE D-2 PLACEMENT OF SAMPLES DOWNWIND OF OBSTRUCTIONS
1. Both the open source height and the obstructions must meet
the required minimum distance criteria.
2. Stability class is determined from cloud cover, wind speed,
and time of day.
3. The height of obstruction or source equals H.
en
«J Stability Minimum distance downwind
Class from obstruction peak
A 5H
B 7H
C 10H
D 17H
E 25Ha
Other Cannot be done
classes
Requires an additional sampler at least 15H downwind for backup.
-------
TABLE D-3. FUGITIVE DUST SAMPLER AND METEOROLOGICAL DATA LOG
Date
Run
Page
Time
(24 hr.
clock)
Totals
Average
Total el
Wind
Speed Direction
mph
avg.
range
Compass
degrees
avg.
range
apsed time
Sl
Roto
cfm
Act
cfm
S2
Roto
cfm
Act
cfm
S3
Roto
cfm
Act
cfm
S4
Roto
cfm
Act
cfm
Other comments
Sampling crew
-------
Run No
DATE
actual barometric
pressure
dry bulb
wet bulb
Op
op
Op
Op
ATMOSPHERIC STABILITY DETERMINATION
reference
line
sampler
centerline
A
B
C
D
E
P
a
ft. (measured)
ft. "
ft. "
ft. "
ft. "
ft- (estimated)
ft. "
TIME
STABILITY
COMMENTS:
Sampler
S
Filter No.
Brinks sampler located next to S
wind instrument is behind S_
obtain sample of source before signing sheet
Sampling
crew
Figure D-l. Fugitive dust sampling worksheet.
61
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APPENDIX E
COMPUTATION OF COMBINED ERRORS
The value of emission rate, Q, is determined in the field by
application of Gaussian dispersion equations to the concentrations
obtained at high volume samplers. These emission values have a
standard deviation which is a function of the standard deviation
of the variables. The emission rate is calculated using Turner's
(14) estimates of atmospheric dispersion from ambient measurement
of X. In such estimates, there is an error due to inconsistent
airflow rates and there are errors in time measurements and weigh-
ing which are part of the emission error.
The values of atmospheric stability as reflected by the standard
deviations (a) in the horizontal and vertical planes are valid
for a sampling time of 10 minutes. The vertical deviation is
expected (14) to be correct within a factor of 2 for: 1) all
stabilities out to a few hundred meters, and 2) neutral to moder-
ately unstable conditions in the lower 1,000 meters of the atmos-
phere with a marked inversion above for distances out to 10 kilom-
eters or more. Since all sampling was performed within a few
hundred meters of the coal pile, these conditions were met. The
estimate of horizontal dispersion, ay, will be less uncertain than
that of az. The emission determined will therefore be (for the
three cases cited) within a factor of 3 for variations of Oy, az
and u (14). Hence, the overall standard deviation in determining
emission rate can be estimated as follows:
a = (a^2 + (a2)2 (E-l)
where a^ = estimated population standard deviation from
sampling for X
a 2 = additional standard deviation in calculation of
Q from X
A factor of 3 is defined as follows:
X + P2 _ o /
X - 02 ~ 3 {
where X = any average value calculated or measured.
62
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From Equation E-2, a factor of three in the calculation of Q
implies
Example 1
and
Hence,
and
Example 2
and
Hence,
then
a2 = 0.5X
X = 6.4 mg/kg-yr
ai = 2.9 mg/kg-yr
a2 = 0.5 (6.4) = 3.2 mg/kg-yr
a = (2.9)2 + (3.2)2 =4.3 mg/kg-yr
X = 336 mg/kg-yr
a i = 200 mg/kg-yr
a 2 = 0.5 (336) = 168 mg/kg-yr
(E-2)
a =
-------
APPENDIX F
DETERMINATION OF DISTANCE TO PLANT BOUNDARY AND
POPULATION DENSITY FOR REPRESENTATIVE COAL STORAGE PILE
A survey was conducted of the same 12 sites used to determine pile
height (Appendix C). These sites were originally selected at
random and cover the spectrum of coal storage users as shown in
Table F-l. Values which are three standard deviations beyond the
mean were discarded to achieve the means presented. Since this
would normally bias the results, deviations were discarded in pairs
(a high and a low).
TABLE F-l.
DISTANCE TO PLANT BOUNDARY AND POPULATION DENSITY
FOR REPRESENTATIVE COAL STORAGE PILE
Site
Mean
(metric units)
Coal pile size,
tons
122 x 103
metric tons
Distance to
boundary,
ft
Population
density,
persons/mile2
1
2
3
4
5
6
7
8
9
10
11
12
Mean (biased)
Standard
deviation
3,000
73,000
63,700
42,000
461,000
280,000
11,000
50,000
584,000
45,000
4,000
3,000
135,000
198,000
440
150
200
50
500
300
50
800
2,600
150
10
175
288
236
52
1,060
63
58
3
1
10
68
417
42
78
4
155
306
86 m
61 persons/km2
64
-------
APPENDIX G
ANALYSIS OF COAL STORAGE PILES FOR
POLYCYCLIC ORGANIC MATERIALS
Two samples from coal storage piles were selected for analysis of
polycyclic organic materials (POM1 ) by chemical ionization mass
spectroscopy. The results are shown in Table G-l. The first
sample was from a coal storage pile at an open pit mine where the
coal had been aged for about 10 days at the most. The coal seam
where this coal originated is typical of western subbituminous coal,
The second sample is from an Indiana coal seam and is typical of
interior region bituminous coal. This sample had aged for approx-
imately 60 days and shows measurable quantities of benzo (c)phenan-
threne, benzo (a)pyrene and 3-methylcholanthrene.
From Appendix A the average emission rate is 19 mg/s from coal
storage piles. Taking an order of magnitude rise in a POM concen-
tration (to account for unknowns) to 5 yg/g of coal, the emission
rate (Q) for POM's would be 0.0095 yg/s. Severity is calculated
using the noncriteria formula developed in Appendix H shown as
follows :
c = 316 Q ,
(TLV) Dl • 814
For the POM calculation, the minimum representative distance (D)
is 83 m and the TLV is 1 yg/m3. Thus, the severity is 0.0099 for
a representative coal pile which is two orders of magnitude below
the severity for coal dust.
65
-------
TABLE G-l.
ANALYSIS OP COAL SAMPLES EXTRACTED WITH PENTANE
FOR SELECTED POLYCYCLIC ORGANIC MATERIALS (POM'S)
BY CHEMICAL IONIZATION MASS SPECTROSCOPY
Concentration, ppm (w/w)
Open pit mine Indiana
coal storage coal storage
Benzo (c) phenanthrene
7 , 12-Dimethylbenz (a) anthracene
Benzo (a) pyrene
3-Methylcholanthrene
Dibenz (a , h) anthracene
Dibenzo (c , g) carbazole
Dibenzo (a, h) pyrene
Dibenzo (a , i ) pyrene
ND
ND
Oi
<
ND
ND
ND(
ND(
(<0.
2)
0.
5
±
(<0.2) <0.
0.2
0.2
(<0.
(<0.
<2)
<2)
2)
2)
0.
0.
ND
ND
ND
ND
3
4
(
(
(
(
+
+
<
<
<
<
0
2
0
0
0.
0.
2)
2)
.1
.1
.1
2)
2)
No signal was detected for the molecular weight plus one atomic
mass unit ions of these compounds at their respective retention
times.
'Unidentified peaks which eluted prior to the appearance of the
first polycyclic organic compound listed above were present in
this sample.
66
-------
APPENDIX H
DERIVATION OF SOURCE SEVERITY EQUATIONS
1. SUMMARY OF MAXIMUM SEVERITY EQUATIONS
The maximum severity of pollutants may be calculated using the
mass emission rate, Q, the height of the emissions, h, or the
distance from the source to the nearest plant boundary, D, and the
threshold limit value, TLV. The equations summarized in Table
H-l are developed in detail in this appendix.
2. DERIVATION OF x^ FOR USE WITH U.S. AVERAGE CONDITIONS
max
The most widely accepted formula for predicting downwind ground
level concentrations from a point source is (14);
X =
Q
"OyO.
(H-l)
where X = downwind ground level concentration at reference co-
ordinate x and y with emission height of h, g/m3
Q = mass emission rate, g/s
ay = standard deviation of horizontal dispersion
az = standard deviation of vertical dispersion
u = wind speed, m/s
y = horizontal distance from centerline of dispersion, m
h = height of emission release, m
x = downwind dispersion distance from source of emission
release, m
TT = 3.1416
67
-------
TABLE H-l. POLLUTANT SEVERITY EQUATIONS
Pollutant Severity equation
For elevated sources:
Particulate
Hydrocarbons
Carbon monoxide
Other
SO
NO
_ , .,
Carbon monoxide
h2
SO ™J
h2
NO
h2.1
162 Q
h2
0.78 Q
h2
5.5 Q
TLV • h2
For ground level sources: , non n
Particulate 4/02° Q
D1.81
2'870 Q
Dl.81
22'200
x l. 90
Hydrocarbons
D1.81
44.8 Q
D
1.81
Other 316 Q
TLV • Dl'
68
-------
We assume that Xraax occurs when x »0 and y = 0. For a given
stability class, standard deviations of horizontal and vertical
dispersion have often been expressed as a function of downwind
distance by power law relationships as follows (30):
ay = axb (H-2)
a = cxd + f (H-3)
2
Values for a, b, c, d and f are given in Tables H-2 and H-3 (31).
Substituting these general equations into Equation H-l yields:
acirux + airufx
(H~4)
Assuming that Xmax occurs at x <100 m or the. stability class is C,
then f = 0 and Equation H-4 becomes:
x =
Q
acTrux
(H-5)
For convenience, let:
A = __ and B =
R
aciru 2c2
so that Equation H-5 reduces to:
x = ADx-(b'"' expl— *| (H-6)
(30) Martin, D. 0., and J. A. Tikvart. A General Atmospheric Dif-
fusion Model for Estimating the Effects on Air Quality of One
or More Sources. Presented at the 61st Annual Meeting of the
Air Pollution Control Association, St. Paul, Minnesota, June
23-27, 1968. 18 pp.
(31) Tadmor, J., and Y. Gur. Analytical Expressions for the
Vertical and Lateral Dispersion Coefficients in Atmospheric
Diffusion. Atmospheric Environment, 3 (6):688-689, 1969.
69
-------
TABLE ft-2. VALUES OF a FOR THE COMPUTATION
OF
(31)
Stability class
A
B
C
D
E
F
a
0.3658
0.2751
0.2089
0.1471
0.1046
0.0722
For the equation
ay - ax
where x = downwind distance
b = 0.9031
TABLE H-3. VALUES OF THE CONSTANTS USED TO
ESTIMATE VERTICAL DISPERSION3 (31)
Usable range, m
Stability
class
Coefficient
>1,000
A
B
C
D
E
F
0.00024
0.055
0.113
1.26
6.73
18.05
di
2.094
1.098
0.911
0.516
0.305
0.18
-9.6
2.0
0.0
-13
-34
-48.6
100 to 1,000
A
B
C
D
E
F
0.0015
0-028
0.113
0.222
0.211
0.086
d2
1.941
1.149
0.911
0.725
0.678
0.74
9.27
3.3
0.0
-1.7
-1.3
-0.35
<100
A
B
C
D
E
F
C3
0.192
0.
0.
,156
,116
0.079
0.063
0.053
0.936
0.922
0.905
,881
,871
0.
0.
0.814
For the equation
= ex" + f
70
-------
Taking the first derivative of Equation H-6
x-b-a
(exp [BRX-^])(-2dBRx-^-.)
+ exp[BRx~2d] (-b-d)x-b-d-ij (H-7)
and setting this equal to zero (to determine the roots which give
the minimum and maximum conditions of x with respect to x) yields:
|| = 0 = A^-b-^1 (exp [BRx-2d]) |^2dBRx-2d-b-d]
(H-8)
Since we define that x ^ 0 or °° at x , the following expression
must be equal to 0:
-2dBRx-2d-d-b =0 (R_9)
or (b+d)x ~ = -2dB
2d
—- _ ~ 11* TJ
(H-10)
x2d = ^2dBR = 2dh2
or
b+d 2c2(b+d)
v2d - d h2
j^, — " — •» "•
c2(b+d)
* - / d h2 \ld ^
(c^b^7J atx-x
Thus Equations H-2 and H-3 become:
b
71
-------
a = c
(H-15)
c2(b+d)/ \b+d
The maximum will be determined for U.S. average conditions of
stability. According to Gifford (32), this is when a = a .
Since b = 0.9031, and upon inspection of Table H-2 (31) under U.S.
average conditions, ay = az, it can be seen that 0 . 881 <_ d <_ 0. 905
(class C stability3). Thus, it can be assumed that b is nearly
equal to d or:
a. - ^ (H-16)
and
a = * Jl (H-17)
Y c /2
Under U.S. average conditions, ay = az and a - c if b - d and f = 0
(between class C and D, but closer to belonging in class C) .
Then ' % = -T (H-18)
y /2
Substituting for oy and az into Equation H-l and letting y = 0:
= 2 Q
TTUh2
(H-19)
or
v = (H-20)
max
The values given in Table H-3 are mean values for stability
class. Class C stability describes these coefficients and
exponents, only within about a factor of two (14).
(32) Gifford, F. A., Jr. An Outline of Theories of Diffusion in
the Lower Layers of the Atmosphere. In: Meteorology and
Atomic Energy 1968, Chapter 3, D. A. Slade, ed. Publication
No. TID-24190, U.S. Atomic Energy Commission Technical Infor-
mation Center, Oak Ridge, Tennessee, July 1968. p. 113.
72
-------
For ground level sources (h = 0) , Xmax occurs by definition at the
nearest plant boundary or public access. Since this occurs when
y = 0, Equation H-l becomes:
TTO 0 U
y z
From the foregoing analysis of U.S. average conditions, class C
stability coefficients are the best first approximations to U.S.
average conditions when a = a .
By letting D equal the distance to the occurrence of Xmax (see
Tables H-2 and H-3) ,
cr = 0.209 D°- 9031 (H-22)
a = 0.113 D°-911 (H-23)
z
Thus, Xmax is determined as follows:
X = 42'36 Q (H-24)
maX TTUP L814
It will be noted that Equations H-24 and H-20 are identical with
the algebraic substitution of
h2 = 0.01737 D1-814 (H-25)
For U.S. average conditions u = 4.47 m/s so that Equation H-20
reduces to:
X = °-0524 Q (H-26)
max h2
3. DEVELOPMENT OF MAXIMUM SOURCE SEVERITY
The general source severity, S, relationship has been defined as
follows:
S = (H-27)
where x = mean ambient concentration
F = severity factor
73
-------
a. Noncriteria Emissions
The value of x may be derived from Xmax, an undefined "short term"
concentration. An approximation for longer term concentration may
be made as follows (14):
For a 24 hour time period,
/t \°-17
X! = v I maxl (H-28)
or
v 0- 17
/ 3 min
~ xmax
/ \°* 17
/ 3 m:Ln } (H-29)
ll,440 miny
X, - Xmax (0.35,
Since the severity factor is defined and derived from TLV values
as follows:
* -
(H-31)
F = (3.33 x 10~3) TLV (H-32)
then the severity factor, S, is defined as:
8. .
F (3.33 x 10"3) TLV
105 x
max (H-34)
TLV
If a weekly averaging period is used, then:
/ 3 \°*17
\ = *max (107080 ) (H-35)
or
X, =
(H-36)
74
-------
and
F = (2.38 x 10~3)TLV (H-38)
and the severity factor, S, is:
s . l = _ (H.39)
F (2.38 x 10~3) TLV
or
105x
max
max
which is entirely consistent, since the TLV is being corrected for
a different exposure period.
Therefore, the severity can be derived from Xmax directly without
regard to averaging time for non-criteria emissions. Thus,
combining Equations H-40 and H-26, for elevated source, gives:
- 5*5 Q
b. Criteria Emissions
For the criteria pollutants, established standards may be used as
F values in Equation H-27. These are given in Table H-4. However,
Equation H-28 must be used to give the appropriate averaging
period. These equations are developed for elevated sources using
Equation H-26.
(1) CO Severity —
The primary standard for CO is reported for a 1-hr averaging time;
therefore ,
t_ =60 min
j-i
= 3 min
0.17
xmax = xmax 60 (H~42)
75
-------
TABLE H-4. SUMMARY OP NATIONAL AMBIENT AIR
QUALITY STANDARDS (33)
Pollutant
Particulate
matter
S0x
Carbon
monoxide
Nitrogen
dioxide
Photochemical
oxidants
Hydrocarbons
(nonme thane)
Averaging
time
Annual (geometric
mean)
24-hourb
Annual (arith-
metic mean)
24-hourb
3-hourb
8-hour
l-hourb
Annual (arith-
metic mean)
l-hourb
3-hour
(6 a.m. to 9 a.m. )
Primary
standards
75
260
80
365
10
40,000
100
160
160
ug/m3
Mg/m3
lig/m3
lig/m3
_
mg/m3
ug/ro3
Mg/m3
ug/m3
ug/m3
Secondary
standards
60a yg/m3
160 yg/m3
to ug/m3
260C wg/m3
1,300 iig/m3
(Same as
primary)
(Same as
primary)
(Same as
primary)
(Same as
primary)
The secondary annual standard (60 yg/m3} is a guide for assess-
ing implementation plans to achieve the 24-hour secondary
standard.
Not to be exceeded more than once per year.
The secondary annual standard (260 ug/m3) is a guide for
assessing implementation plans to achieve the annual standard.
2 Q _
•rreuh2 60
2 Q
= (3.14) (2.72) (4.5) h2 (°'6)
0.052 Q
h2
(0.6)
(3.12 x 10~d)Q
xmax
h2
Severity, S, =
(H-43)
(H-44)
(H-45)
(H-46)
(H-47)
Setting F equal to the primary standard for CO, i.e., 0.04 g/m3
yields:
S =
xmax _ (3.12 x 10~2)Q
0.04 h2
(H-48)
or
'CO
0.78 Q
h2"
(H-49)
(33) Code of Federal Regulations, Title 42 - Public Health,
Chapter IV - Environmental Protection Agency, Part 410 -
National Primary and Secondary Ambient Air Quality Standards,
April 28, 1971. 16 pp.
76
-------
(2) Hydrocarbon Severity--
The primary standard for hydrocarbon is reported for a 3-hr aver-
aging time.
tT = 180 min
Jj
Snax = 3 min
xmax xmax
0-17
I 3 \ (H-50)
I18°j
(H-51)
" °'5xmax
(0.5) (0.052) Q
(H-52)
h2
0.026 Q
h2
W • V/ fc« V/ W
xmax = : (H-53)
For hydrocarbons, F = 1.6 x 10-1* g/m3
and
S = = °-026 Q (H-54)
F 1.6 x lO
or
Q - 162.5 Q .„ ,.,..
S _, = (H-55)
v,2
(3) Particulate Severity—
The primary standard for particulate is reported for a 24-hr aver-
aging time.
0.17
/ 3 >
= XT
max
(l,440J
^
max
= (0.052) Q (0,351 (H-57)
h2
= (0-0182) Q (H_58)
77
-------
For particulates, F = 2.6 x 10"^ g/m3
0.0182 Q (H-59)
2.6 x 10-** h2
s = 70 Q (H-60)
P h2
(4) SO Severity —
The primary standard for SO is reported for a 24-hr averaging
time.
- = (0.0182) Q (
xmax h2
The primary standard is 3.65 x 10-tf g/m3
and
_ xmax __ (0.0182)0 ,„
-
F
3.65 x 10-1* h2
or
sso = *rr
x h2
(5) NO Severity—
Since NOx has a primary standard with a 1-yr averaging time, the
Xmax correction equation cannot be used. As an alternative,
following equation was selected:
- 2.03 Q
X= — exp
A 0 ux ^
z
1 /h
1
I 57 (H-64>
A difficulty arises, however, because a distance x, from emission
point to receptor, is included and hence, the following rationale
is used:
The equation xmax
78
-------
is valid for neutral conditions or when a =a . This maximum
occurs when
z y
and since, under these conditions,
°z = axb
then the distance x where the maximum concentration occurs is:
luciX
1
h \ b
max
For class C conditions,
Simplifying Equation H-64,
a = 0.113
b = 0.911
since
and
xmax
u = 4.5 m/s
0.911
Letting x = x in Equation H-64,
3 max
X =
4 Q
X
max
[-»
098
__
max 0.16
c = 7.5 h1-098
max
2-,
(H-65)
(H-66)
(H-67)
and
4 Q
4 Q
x
1-3H
max
(7.5
- . 0.085 Q
h2.1
[-»«•
(H-68)
(H-69)
a = 0.113x0-911
z
(H-70)
79
-------
= 0.113 (7.5 hl-l)°'911
(H-71)
a = 0.71 h
z
(H-72)
Therefore
X - J^SJLfi exp
h2-1
2n
.71
(H-73)
0.085 Q
h2.1
(0.371)
(H-74)
- 3.15 x 10" Q
(H-75)
Since the NO standard is 1.0 x
, • • .X.
tion is:
g/m3, the NO severity equa-
NO
(3.15 x 10"2) Q
x 1 x lO"4
(H-76)
h2.1
(H-77)
80
-------
GLOSSARY
active coal pile: aggregates of bituminous or subbituminous coal
stored without any coating to prevent oxidation.
asphyxia: loss of consciousness as a result of too little oxygen
and too much carbon dioxide in the blood.
atmospheric stability class: categories used to describe the tur-
bulent structure and wind speed of the atmosphere.
avalanching: the continuous deposition and resuspension of loose
soil particles blowing across a field.
background level: concentration of pollutants in the air prior to
the addition of pollutants from the source of interest.
Brink samples: particle size distributed samples of particulate.
calibrating orifice assembly: a unit connected to the inlet of a
high volume sampler for calibration.
catalytic reduction tube: a device used for conversion of carbon
monoxide to methane via a nickel catalyst for detection by
flame ionization chromatography.
chemical ionization mass spectroscopy: method of chemical analysis
in which ions are passed in a vacuum first through an acceler-
ating electric field and then through a strong magnetic field.
chromatographic column: long tube packed permeably with some
absorbent for separating components of mixtures.
clump detachment: bulk dispersal of particle deposits from a dust
pile in a wind tunnel.
coal tar derivatives: black, viscous liquids obtained from the
destructive distillation of coal.
coal erodibility: capacity of coal for disintegration.
cohesive deposits: dust piles of coal with a particle size range
of 6 ym to 8 ym.
81
-------
composite TLV: threshold limit value of a compound based on the
concentrations and threshold limit values of each of the
elements.
confidence level: the probability that a random variable lies
within a specified range given a known distribution of that
variable.
confidence limits: upper and lower boundaries of values that a
random variable lies between with a specific probability.
criteria pollutant: pollutant for which ambient air quality stand-
ards have been defined.
elevated sources: sources with a point of emission above ground
level.
emission burden: ratio of emissions from a source to the total
emissions per state or nation.
emission factor: emission rate divided by coal storage pile
capacity.
entrainment rate: rate of material dispersal from a dust pile.
flame ionization detector: device which measures the electrical
conductivity of a flame.
flame photmetric: emission of radiation (photons) by an element
in a flame.
free-flowing deposits: dust beds containing particles in the size
range of 100 ym to 150 pm.
gross particulate: the entire quantity of respirable particulates
considered as inert, nuisance particulates.
hazard factor: toxicity of a pollutant corrected for a 24 hr
exposure with a safety factor of 100.
impact factor: a factor which shows the relative environmental
impact of emission sources for use in assigning priorities in
investigative work.
implementation plans: procedures for achieving ambient air quality
standards.
inactive coal pile: coal stockpile coated with a tar derivative to
prevent oxidation.
insolation class: a categorization for various levels of incoming
solar radiation.
82
-------
mass coal dust: respirable suspended particulate which is found in
coal mines, as differentiated from ambient particulate matter.
noncriteria pollutants: pollutants for which ambient air quality
standards have not been established.
Nucleopore: a polycarbonate filter medium.
open sources: fugitive sources which do not have a definable point
of emission such as a stack or vent.
pneumoconiosis: any of various diseased conditions of the lung
characterized by fibrous hardening as a result of chronic
inhalation of irritating dust particles.
quartz: a brilliant, crystalline mineral as silicon dioxide.
radiation index: a reference to the amount of incoming sun rays
that strike the earth's surface.
respirable range: all of those particulates less than 7 ym in
diameter.
sensitivity analysis: mathematical technique in which the effect
of one parameter is observed over a range of possible values
while the remaining parameters are kept constant.
spectrographic analysis: study of the dispersal of light into a
spectrum passing through a medium.
stripper column: a column in series with the analytical column
which H2O, C02, and hydrocarbons (ex. CUk) are removed.
Thornthwaite1s P-E index: a relationship expressing the amount of
precipitation and the mean temperature in a given region.
weathering: erosive effects of the forces of weather on a coal
pile.
x-ray fluorescence: analytical technique in which x-rays are
absorbed depending upon the wavelength and the material.
83
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing}
i. REPORT NO.
EPA-600/2-78-004k
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
6. REPORT DATE
May 1978 issuing date
SOURCE ASSESSMENT: COAL STORAGE PILES
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
T. R. Blackwood and R. A. Wachter
8. PERFORMING ORGANIZATION REPORT NO.
MRC-DA-504
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Monsanto Research Corporation
1515 Nicholas Road
Dayton, Ohio 45407
10. PROGRAM ELEMENT NO.
1BB610
II.CONTRACt/ORANtNO:
68-02-1874
SPONSORING. AGENCV NAME AND ADDRESS
Industrial Environmental Research Lab-Cinn., OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Task Final, 5/74-9/75
14. SPONSORING AGENCY CODE
EPA/600/]?
15. SUPPLEMENTARY NOTES
IERL-Ci project lead for this report is John F. Martin,
513/684-4417
16. ABSTRACT
This report describes a study of atmospheric emissions from coal storage
piles. Fugitive emissions of dust and gases are emitted from coal storage
piles. The average emission factor for respirable particulate (<7 pm)
is 6.4 mg/kg per annum; this factor describes the emission rate 95% of the
time within 108%. From the distribution of coal piles, a representative
pile was selected containing 95,000 metric tons of bituminous coal. The
emission rate from this pile averages 19 mg/s or 610 kg/yr. In order to
evaluate the potential environmental effect of coal storage piles, a
severity factor was defined as the ratio of the maximum ground level con-
centration of an emission to the ambient air quality standard for criteria
pollutants and to a modified threshold limit value for other pollutants.
Severity factors for a representative coal storage pile are 0.025 and 1.0
when the emissions are treated as gross particulate and coal dust, respec-
tively. The national emission burden from all coal storage piles is
0.00048% of total national particulate emissions. The amount of coal
stored is increasing at the rate of 3.8% per year and this will result in
a 25% increase in emissions in 1978 compared to 1972. Air pollution con-
trol techniques for coal storage piles have not been generally established
and no future control techniques are presently under consideration.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air Pollution
Coal
Dust
Gases
b.IDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control
Stationary Sources
Source Severity
Particulate
COSATI Field/Group
68A
18. DISTRIBUTION STATEMEN1
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report/
UNCLASSIFIED
21. NO. OF PAGES
98
2O SECURITY CLASS (This page I
UNCLASSIFIED
??. PRICE
EPA Form 222O-1 (»-73)
84
ftU.S. GOVERNMENT PRINTING OFFICE, 1978— 757-140/6851
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