EPA-600/2-76-032C
March 1976
Environmental Protection Technology Series
SOURCE ASSESSMENT:
FERTILIZER MIXING PLANTS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
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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 five series These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socibeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control and
treatment of pollution sources to meet environmental quality standards
EPA REVIEW NOTICE
This report has been reviewed by the U. S. Environmental
Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect the
views and policy of the Agency, nor does mention of trade
names or commercial products constitute endorsement or
recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service. Springfield. Virginia 22161.
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EPA-600/2-76-032c
March 1976
SOURCE ASSESSMENT:
FERTILIZER MIXING PLANTS
by
Gary D. Raw!ings and Richard B. Reznik
Monsanto Research Corporation
Dayton Laboratory
Dayton, Ohio 45407
Contract No. 68-02-1874
ROAP No. 21AXM-071
Program Element No. 1AB015
EPA Project Officer: D.A. Denny
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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PREFACE
The Industrial Environmental Research Laboratory (IERL) of
EPA has the responsibility for insuring that air pollution
control technology is available for stationary sources. If
control technology is unavailable, inadequate, uneconomical
or socially unacceptable, then development of the needed
control technology is conducted by IERL. Approaches con-
sidered include: process modifications, feedstock modifica-
tions, add on control devices, and complete process substi-
tution. The scale of control technology programs range
from bench to full scale demonstration plants.
The Chemical Processes Section of IERL has the responsibility
for developing control technology for a large number (>500)
of operations in the chemical and related 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 control technology by
IERL. This report contains the data necessary to make
that decision for fertilizer mixing plants.
Monsanto Research Corporation has contracted with EPA to
investigate the environmental impact of various industries
which represent sources of emissions in accordance with EPA's
responsibility as outlined above. Dr. Robert C. Binning
serves as Program Manager in this overall program entitled,
"Source Assessment," which includes the investigation of
sources in each of four categories: combustion, organic
materials, inorganic materials and open sources. In this
study of fertilizer mixing plants, Mr. Edward J. Wooldridge
served as EPA Project Leader.
111
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CONTENTS
Section Page
I Introduction 1
II Summary 3
III Source Description 13
A. General Description 13
B. Raw Materials 23
1. Primary Nutrients 23
2. Secondary and Micronutrient 25
Materials
3. Pesticides 26
C. Ammoniation-Granulation Plants 33
1. Process Description 33
2. Pugmill Ammoniator 38
3. Rotary-Drum Ammoniator-Granulator 38
4. Raw Materials 42
5. Emission Sources 44
D. Bulk Blending Plants 46
1. Process Description 46
2. Types of Mixers 49
3. Raw Materials 51
4. Emission Sources 51
E. Liquid Mix Plants 56
1. Process Description 56
2. Hot Mix Plants 59
3. Cold Mix Plants 69
4. Raw Materials 69
5. Emission Sources 72
IV Emissions 75
A. Ammoniation-Granulation Plants 76
1. Selected Emissions 76
2. Emission Characteristics 82
B. Bulk Blending Plants 88
1. Selected Emissions 88
2. Emission Characteristics 92
v
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IV Emissions (continued) Page
C. Liquid Mix Plants 94
1. Selected Emissions 94
2. Emission Characteristics 97
D. Environmental Effects 99
V Control Technology 109
A. Ammoniation-Granulation Plants 109
1. Process Modifications 109
2. Pollution Control Devices 112
B. .Bulk Blending Plants 125
1. Process Modifications 125
2. Pollution Control Devices 130
C. Liquid Mix Plants 138
1. Process Modifications 138
2. Pollution Control .Devices 138
VI Growth and Nature of the Industry 141
VII Appendixes 149
A. Granular Raw Materials Consumed at 150
Fertilizer Mixing Plants in the U.S.
B. Raw Data used to Calculate Emission 151
Factors for Ammoniation-Granulation
Plants
C. TLV's for the Raw Materials/ Secondary, 156
and Micronutrients used by Fertilizer
Mixing Plants
D. Details of Sampling Presurvey at 157
Bulk Blending Plants
E. TLV and LD50 Values for Selected 164
Herbicides (Active Ingredients) used
at Fertilizer Mixing Plants
F. Data used to Establish Emission Fac- 165
tors for Hot Mix Liquid Mix Fertilizer
Plants
G. Mass of Particulate Emissions from 166
Fertilizer Mixing Plants
H. Captial and Operating Costs for High 169
Efficiency Wet Scrubbers
VIII Glossary of Terms 177
IX Conversion Factors and Metric Prefixes 179
X References 181
vi
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LIST OF FIGURES
Figure
1 Types of Fertilizers Consumed in the U.S.
2 Distribution of Commercial Fertilizers
Consumed in the United States in 1973
3 Proportion of Mixed Fertilizer Grades 16
Consumed in 1973
4 Three Types of Fertilizer Mixing Plants 17
5 Basic Process Flow Diagrams for Fertilizer 19
Mixing Plants
6 Fertilizer Production by the Three Types 20
of Mixing Plants
7 Geographical Distribution of Herbicides 32
Applied to Crops in 1971
8 Geographical Distribution of Ammoniation- 34
Granulation Mixing Plants in 1973
9 Generalized Flow Diagram of an Ammoniation- 36
Granulation Fertilizer Plant
10 TVA Continuous Ammoniator-Granulator 40
11 Conventional Ammoniation-Granulation Plant 41
with a Rotary-Drum Ammoniator
12 Geographical Distribution of Fertilizer 47
Bulk Blending Plants in 1973
13 Bulk Blending Plant with a Ground Level 48
Rotary Mixer
14 Spray System for Coating Granules in 52
Rotary Mixer
15 Bulk Loading Station with Elevated Storage 55
Used in Bulk Blending
16 Geographical Distribution of Liquid Mix 57
Fertilizer Plants in 1972
17 Generalized Flow Diagram of the Production 58
of Liquid Mixed Fertilizers
18 Types of Liquid Mixed Fertilizer Plants 58
19 Reactor Assembly for the Production of 61
Liquid Fertilizer
20 TVA Liquid Fertilizer Suspension Mix Plant 63
21 Hot Mix Plant for the Continuous Production 64
of Clear Liquid Fertilizers
VI1
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LIST OF FIGURES (continued)
Figure Page
22 Hot Mix Plant for the Batch Production 65
of Clear Liquid Fertilizers
23 Plant Using Pipe Reactor Process, with Wet 67
Scrubber Separate Mix Tank and Pipe-Type
Coolers
24 Plant Using Pipe Reactor Process with Tower 68
Design
25 Diagram of a Liquid Cold Mix Plant 70
26 General Distribution of Mean Source 107
Severity as a Function of Distance From the
Source, Showing the Two General Roots to
the Plume Dispersion Equation
27 Particulate Collection Efficiencies for 110
Various Types of Control Equipment
28 Cyclone Gas Velocity Control 113
29 Utilization of Dryer and Cooler Exhaust 114
Blower to Remove In-Plant Dust
30 Dust Collector Seal 115
31 Dust-Tight Cyclone Closure, Molded Rubber 116
Seal
32 Impingement Type Scrubber 118
33 Cyclonic Scrubber 119
34 Two-Stage Cyclonic Scrubber 121
35 Venturi Cyclonic Scrubber 122
36 Packed Bed Scrubber 123
37 Dust Depressant Application System 129
38 Bulk Blend Plant Equipped with Dust 131
Controls
39 Alternative Dust Control Systems 132
40 Bin-Filling Arrangement 134
41 Bucket Elevators Used in Bulk Blending 136
Plants
42 Vane Type Seal for Bucket Elevator 137
43 Suggested Fume Scrubbing System for 139
Fluid Plant
44 Fertilizer Consumption from 1960 to 1980 142
Vlll
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LIST OF FIGURES (continued)
Figure
45 Portion of the Mixed Fertilizer Market
Shared by the Three Types of Mixing Plants
46 Nitrogen Supply Forecast for the U.S. 145
47 Phosphate Supply Forecast for the U.S. 145
48 Potash Supply Forecast for the U.S. 145
IX
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LIST OF TABLES
Table
1 Average Operating Conditions for
Representative Fertilizer Mixing Plants
2 Emission Factors and Total Masses of 7
Controlled Emissions from Fertilizer
Mixing Plants
3 Summary of Xmax Values and Source Severity 8
for Emissions from Representative Mixing
Plants
4 Affected Population Around Representative 9
Fertilizer Mixing Plants
5 Production Statistics for Fertilizer 22
Mixing Plants in 1973
6 Raw Materials Consumed by Fertilizer 24
Mixing Plants in 1972
7 Quantities of Secondary and Micronutrient 26
Fertilizer Materials Consumed in the U.S.
in 1972
8 Principal Inorganic Forms of Micronutrients 27
9 Principal Organic Forms of Micronutrients 28
10 Estimated Quantities of Selected Herbicides 30
(Active Ingredients) Applied to Crops with
Mixed Fertilizers
11 Types of Raw Materials Consumed by 42
Ammoniation-Granulation Plants
12 Formulation Data for an Ammoniation- 43
Granulation Plant
13 Survey of Bulk Blending Mixer Types 50
14 Estimated Quantities of Selected Herbicides 53
(Active Ingredients) Used by Bulk Blend
Plants
15 Raw Materials Consumed by Liquid Mix 71
Fertilizer Plants
16 Estimated Quantities of Selected Herbicides 73
(Active Ingredients) Used by Liquid Mix
Plants
17 Uncontrolled Emission Factors for 79
Ammoniation-Granulation Fertilizer Plants
18 Stack Data for Ammoniation-Granulation 82
Plants
x
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LIST OF TABLES (continued)
Table
19 Human Hazard Potential Due to Exposure
to Air Emissions from Ammoniation-
Granulation Plants
20 Particle Size Distribution of the Emissions 85
from the Dryer, Cooler, and Bagging Operations
21 Uncontrolled Particulate Emission Factors 89
for Bulk Blending Fertilizer Plants
22 Estimated Maximum Uncontrolled Emission 91
Factors for Secondary and Micronutrient
Materials Used at Bulk Blending Plants
23 Estimated Maximum Emission Factors for 93
Selected Herbicides (Active Ingredients)
Used at Bulk Blending Plants
24 Uncontrolled Emission Factors for Liquid 96
Mix Fertilizer Plants
25 Estimated Maximum Emission Factors for 98
Selected Herbicides (Active Ingredients)
Used at Liquid Mix Plants
26 Maximum Ground Level Concentrations Xmax ^-01
of Controlled Emission Species from
Fertilizer Mixing Plants
27 Values of Mean Source Severity Controlled 102
Emissions
28 Annual Masses of Emissions from Fertilizer 103
Mixing Plants in the U.S.
29 Comparison of Fertilizer Mixing Plant 104
Generated Particulate Emissions to Total
National Particulate Emission Values
30 Distribution of Fertilizer Mixing Plants 106
in Selected States
31 Affected Population Around Representative 108
Fertilizer Mixing Plants
32 Stack Measurements at an Ammoniation- 111
Granulation Plant in Maryland
33 Operating Conditions for a Venturi 124
Cyclonic Wet Scrubber
34 Characteristics of Various Bag Filters 126
35 Effect of 10-34-0 in Depressing Dust in 128
Bulk Blend Plant
XI
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LIST OF TABLES (continued)
Table
36 Ventilation Rates for Bulk Blending
Equipment
B-l Plant Source Test Data 152
B-2 Statistical Analysis of Emissions from 155
Ammoniation-Granulation Plants for 95%
Confidence Limits
D-l Results of Sieve Test for Bulk Blending 160
Plant Raw Materials
D-2 Worsts-Case Emission Factors for the Raw 161
Materials Used by Fertilizer Bulk Blending
Plants
D-3 Emission Factors for Uncontrolled Particu- 163
late Emissions from Fertilizer Bulk Blending
Plants
H-l Estimated Capital Cost Data (Cost in 170
Dollars) for Two-Stage Cyclonic Scrubber
H-2 Annual Operating Cost Data for Two-Stage 171
Cyclonic Scrubbers
H-3 Estimated Capital Cost Data (Costs in 172
Dollars) for Venturi Cyclonic Scrubbers
H-4 Annual Operating Cost Data for Venturi 173
Cyclonic Scrubbers
H-5 Estimated Capital Cost Data (Costs in 174
Dollars) for Packed Crossflow Scrubbers
for DAP Process Plants
H-6 Annual Operating Cost Data for Packed 175
Crossflow Scrubbers
xn
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LIST OF SYMBOLS
Symbol
AAQS
A,B,C,a,b,c
ACMM
ACGIH
DAP
DSCMM
e
F
MP
n
ppm
Q
S
SCM
SCMM
s(X)
s(X)
t
Definition
Ambient air quality standard
Symbols used to designate parameters and
their corresponding variance
Actual cubic meter per minute
American Conference of Governmental
Industrial Hygienists
Diammonium phosphate
Dry standard cubic meter per minute
Natural logarithm base = 2.72
Hazard factor equal to the primary ambient
air quality standard for criteria pollutants
or to a reduced TLV (i.e., TLV-8/24-1/100)
for noncriteria pollutants
Stack height
Chemical dose lethal to 50% of a population
of test animals
Total mass of specific emission species in
state
Total mass of specific emission species from
mixing plants
Number of samples or number of degrees of
freedom
Parts per million
Flow rate of an emission
Source severity
Standard cubic meter
Standard cubic meter per minute
Estimated standard deviation of sample
Estimated standard deviation of the mean
Calculated value which represents the dif-
ference between the mean of a sample and the
true mean of the population from which the
sample was drawn, divided by the estimated
standard deviation of the mean
Xlll
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LIST OF SYMBOLS (Continued)
Symbol Definition
t0 05 ± Values of "Student t" distribution between
which 95% of the area lies
t0 Instantaneous averaging time of 3 minutes
t} Averaging time
TLV Threshold limit value
u National average wind speed
UAP Urea ammonium phosphate
X Mean value of a sample
x Axial distance from an emission source
y True mean of the population
TT 3.14
X Time average ground level concentration of an
emission
X Instantaneous maximum ground level concentra-
ITlclX , *
tion
X Time-average maximum ground level concentra-
max . .
tion
xiv
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SECTION I
INTRODUCTION
Fertilizers in the United States are consumed either as
direct application (single nutrient) fertilizers or as
mixed fertilizers. The latter are defined as fertilizers
which contain more than one of the primary plant nutrients:
nitrogen (N), phosphorus (P), and potassium (K). The four
types of mixed fertilizers are N-P-K, N-P, N-K, and P-K
mixtures.
The potential environmental impact of air emissions from
plants producing mixed fertilizers is evaluated in this
report. To achieve this result, the study identifies the
sources of air emissions, the emission species characteris-
tics, and the process variables that affect the quantity of
emissions. The distribution of air pollution control equip-
ment among the mixing plants is also described.
The fertilizer mixing industry can be divided into three
distinct groups according to production techniques:
ammoniation-granulation, bulk blend, and liquid mix. (The
production of diammonium phosphate was excluded from this
investigation.) Granular mixed fertilizers are produced
by ammoniation-granulation and bulk blending plants, while
liquid mixing plants produce liquid mixed fertilizers.
The report discusses these processes in detail, identifies
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specific emission sources, and evaluates the effects of
process variables on emission rates. It also explains
existing and future air pollution control equipment for this
industry and discusses industry trends.
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SECTION II
SUMMARY
The fertilizer industry in the United States produced
39.1 x 106 metric tons (43.1 million tons) of commercial
fertilizers in 1973. Of that total, 48% or 18.8 x 106
metric tons (20.7 million tons) were direct application,
single nutrient fertilizers, while 52% or 20.3 x 106 metric
tons (22.4 million tons) were mixed fertilizers containing
more than one primary plant nutrient material.
The three primary nutrients required by all plants are
nitrogen (N), phosphorus (P), and potassium (K). Mixed
fertilizers containing varying proportions of these nutrients
are expressed as N-P-K grades, where N represents the per-
centage of available nitrogen, P represents the percentage
of available P2Os/ and K represents the percentage of
soluble K20. The majority (77.5%) of the mixed fertilizers
consumed in the U.S. are mixtures containing all three primary
plant nutrients.
In 1973, there were 8,603 fertilizer mixing plants in the
U.S. located in 47 states and 3,002 (59%) counties. The
majority (55.5%) of the mixing plants, producing 51.0% of
mixed fertilizers, are located in the states of Illinois,
Indiana, Iowa, Minnesota, Missouri, Ohio, and Texas. The
1 metric ton = 106 grams = 2,205 pounds =1.1 short tons;
(short tons are designated "tons" in this document;) other
conversion factors and metric system prefixes are presented
in Section IX.
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majority (82.1%) of the plants are located in counties with
less than 39 persons per square kilometer (100 persons/mi2).
There are three types of fertilizer mixing plants:
Ammoniation-granulation: 195 plants
Bulk blending: 5,640 plants
Liquid mixing: 2,768 plants
Ammoniation-granulation plants mix liquid ammonia and super-
phosphoric acid with granular urea-ammonium nitrate, potash
and other materials in a granulator to produce a granular,
dry mixed fertilizer. At bulk blend plants, granular raw
materials such as diammonium phosphate, urea-ammonium
nitrate, triple superphosphate and potash are physically
mixed, without a chemical reaction, to. produce a dry granular
mixed fertilizer. Liquid mix plants mix liquid raw mater-
ials to produce a fluid mixed fertilizer. While few in
number, ammoniation-granulation plants (excluding diammonium
phosphate plants which are not covered in this report) pro-
duce 45% (9.14 x 106 metric tons) of all mixed fertilizer in
the U.S. Bulk blend and liquid mix plants produce 32%
(6.50 x 106 metric tons) and 23% (4.67 x 106 metric tons)
of the total production, respectively.
The size and specific operating conditions for individual
mixing plants vary widely depending oh plant geographical
location and length of the growing season.
Annual production rates can vary from 103 metric tons to 105
metric tons. Operating periods can vary from 8 hr/day, 5 days/
week, 5 months/yr to 16 hr/day, 6 days/week, 10 months/yr.
Operating conditions for average fertilizer mixing plants
are given in Table 1. The operating conditions summarized
in Table 1 define representative plants which serve as the
basis for characterizing the air emissions as described later.
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Table 1. AVERAGE OPERATING CONDITIONS FOR REPRESENTATIVE
FERTILIZER MIXING PLANTS
Parameter
Production, 10 3 metric tons/yr
(1,000 tons/yr)
Design capacity, metric ton/hr
(tons/hr)
Operating period, hr/yr
Plant type
Ammoniation-
granulation
46.9
(51.7)
22.7
(25)
3,216
Bulk
blend
1.5
(1.27)
13.6
(15)
1,280
Liquid
mix
1.69
(1.86)
13.6
(15)
1,280
Since detailed plant production rates are not available, the
total annual production was divided by the number of plants
(e.g., for ammoniation-granulation, [9.14 x 105 metric tons/yr]
v 195 plants = 46.9 x 103 metric tons/yr-plant) to calculate
average plant production rates.
The emission species from fertilizer mixing plants are:
• Ammonia vapor and ammonium salts
• Chlorine vapor and chloride salts
• Fluorine compounds
• Phosphorus compounds
• Particulates
The emission points for each kind of mixing plant are divided
into several types based on manufacturing process steps and
are outlined below:
Ammoniation-Granulation Plants
• Material storage and handling
• Ammoniator-granulator
• Dryer and cooler
• Screen and oversize mill
• Bagging and loading
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Bulk Blend Plants
• Material storage and handling
• Loading operations
• Fugitive building emissions
Liquid Mix Plants
• Hot mix reactor
• Raw material handling
The emission factors and total masses of emissions from each
type of mixing plant are summarized in Table 2. Ammonia
emissions from the ammoniator-granulator, dryer and cooler at
ammoniation-granulation plants account for 96% of the ammonia
emissions from mixing plants. The larger error values for
particulate emissions are a result of a larger uncertainty
in the emission factors for fugitive particulate emissions.
Fugitive dust is the largest component in emissions from
fertilizer mixing plants.
Total particulate emissions from fertilizer mixing plants
were compared to emissions of particulates from all stationary
sources on a national and statewide basis. It was found
that mixing plants contribute 0.02% of total national
particulate emissions and from 0.001% to 0.2% on a state
level. The average state contribution was 0.03%.
In order to evaluate the potential environmental effect of
fertilizer mixing plant emissions, the time-averaged maximum
ground level concentration, x , w^s calculated for each
IQcLX
emission around the three representative plants (Table 3) .
The values of x were calculated from accepted plume dis-
max
per s ion equations using a 24-hr averaging time and the
emission factors in Table 2.
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Table 2. EMISSION FACTORS AND TOTAL MASSES OF CONTROLLED
EMISSIONS FROM FERTILIZER MIXING PLANTS
Emission species
Ammonia
Total chlorine
Total fluorine
Total phosphorus
Particulate
Ammoniation-granulation plants3
Emission factor,
g/kg
0.12 i 66%
0.0066 ± 175%
0.0014 ± 61%
0.0049 ± 133%
0.21 ± 300%C
Total mass,
metric ton/yr
1,120 ± 740
59 ± 103
13 ± 8
45 ± 60
1,920 ± 5,760
Bulk blend plants
Emission factor,
g/kg
0
0
0
0
0.3 ± 100%.
Total mass,
metric ton/yr
0
0
0
0
1930 ± 1930
Liquid mix plants
Emission factor,
g/kg
0.011 ± 100%
0
0.0002 + 100%
0.0001 ± 100%
0.039 ± 100%
Total mass,
metric ton/yr
50 ± 50
0
1 ± 1
0.4 ± 0.4
181 ± 181
Based on an average control efficiency of 85% for all emission species.
Based on uncontrolled emissions.
CLarge error value because of large uncertainty of fugitive dust emissions.
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Table 3. SUMMARY OF x VALUES AND SOURCE SEVERITY
iUcLX
FOR EMISSIONS FROM REPRESENTATIVE MIXING PLANTS
Plant type
Ammoniation- b
granulation
Bulk blend0
Liquid mix
Emission
species
Ammonia
Chlorine
Fluorine
Phosphorus
Particulate
Particulate
Ammonia
Fluorine
Phosphorus
Particulate
TLVf
mg/m3
18
3
2.5
100
10
10
18
2.5
100
10
Emission factor,
g/kg
0.12 ± 66%
0.0066 ± 175%
0.0014 ± 61%
0.0049 ± 133%
0.21 ± 300%
0.3 ± 100%
0.011 ± 100%
0.002 ± 100%
0.0001 ± 100%
0.039 ± 100%
xmax,
yg/m3
16
0.84
0.18
0.62
27
38
0.64
0.12
<0.01
2.3
Source
severity, S
0.26
0.08
0.02
<0.01
0.10
0.14
0.01
0.01
<0.01
0.01
00
A representative plant is defined in Table 1.
^Emission factors based on an average control efficiency of 85% for
all emission species.
^
"Emission factor for uncontrolled emissions.
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The source severity, S, was defined as the ratio of x to
ITlclX
an F factor. For particulate emissions, F was defined as
the primary ambient air quality standard (AAQS). For other
emission species, F was defined as the TLV® modified for a
24-hour exposure and multiplied by a 1/100 safety factor.
The values of S are shown in Table 3.
Another measure of potential environmental impact is the
population which may be affected by emissions from repre-
sentative fertilizer mixing plants. The affected popula-
tion is defined as the number of persons living in the area
around the plant where X (the time-averaged ground level
concentration) divided by AAQS (or F) is greater than 0.1
or 1.0 Plume dispersion equations are used to find this
area, which is then multiplied by the average population
density (39 persons/km2) to determine the affected popula-
tion. The affected population values for those emission
species which result in a value of S greater than 0.1 and
1.0 are shown in Table 4.
Table 4. AFFECTED POPULATION AROUND REPRESENTATIVE
FERTILIZER MIXING PLANTS
Plant type
Ammoniation-
granulation
Bulk blend
Emission
species
Ammonia
Particulate
Particulate
Affected population,
persons
S >0.1
48
6
2
S >1.0
0
0
0
The types of air pollution control techniques used at
fertilizer mixing plants are as varied as the operating
conditions at each plant. All ammoniation-granulation
plants, however, do use some form of control device, such as
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cyclone, wet scrubber, baghouse, or a combination of devices.
Wet scrubber designs vary from medium efficiency (85% effi-
cient) cyclonic types to high efficiency (>99% efficient)
packed bed and venturi scrubbers. These scrubbers use water
or 30% phosphoric acid solution to recover ammonia and
other gaseous emissions from the ammoniator-granulator. Dry
cyclones and occasionally baghouses (in <10% of the plants)
are used to collect particulate emissions from the dryer,
cooler, screens, and oversize mill. An average ammoniation-
granulation plant uses wet scrubbers to collect emissions
from the ammoniator-granulator and cyclones to collect
particulates emitted from the dryer and cooler. The exhaust
from the cyclones is then vented into the wet scrubber. On
the average, 85% of all emission species at these plants
are collected by these two control devices.
Bulk blending plants do not use control devices because
their particulate emission rates are below all local and
state emission standards. Their emissions are fugitive in
nature, in that they are not emitted from a stack but rather
from doors and windows in the blending plant building.
Of the 2,768 liquid mix plants, only the 100 pipe reactor-
type plants require emissions control. These plants either
have wet scrubbers or are stacked tower design plants in
which the cooling tower acts as a wet scrubber in addition
to cooling the product.
The mixed fertilizer industry has grown at a rate of 3% to
5% per year for the past 3 years. This steady increase is
expected to continue for another 2 years. A more rapid
increase will not take place until the current shortage of
available raw materials, such as nitrogen and potash, has
ended. The shortage in materials is due primarily to an
10
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increased demand without a corresponding increase in raw
material production'facilities. In addition, the current
energy crisis has reduced the availability of the natural
gas feedstock required to produce ammonia.
Based on the expected growth rate, the emissions from
fertilizer mixing plants are expected to increase at
approximately 3%/yr for the next 3 years. This increase
in emissions will taper somewhat as the smaller ammoniation-
granulation plants are phased out and replaced by larger
plants that are equipped with more efficient emissions con-
trol equipment.
11
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SECTION III
SOURCE DESCRIPTION
A. GENERAL DESCRIPTION
The U.S. Department of Agriculture reports than 39.1 x 106
metric tons of commercial fertilizers were consumed in the
U.S. for the fertilizer year of July 1, 1972 to June 30,
1973. l This is a 4% increase over .the 37.4 x 106 metric tons
consumed during the 1972 fertilizer year. These figures
represent all commercially produced fertilizers sold or
shipped for farm and nonfarm use as fertilizer.
Of the 39.1 x 106 metric tons of fertilizers consumed,
18.8 x 106 metric tons, or 48% were direct application ma-
terials, and 20.3 x 106 metric tons, or 52% were mixed
fertilizers (Figure 1 and Figure 2). Direct application
materials include single nutrient fertilizers (nitrogen, N;
phosphate, PaOs; and potash, K20; which totaled 17.4 x 106
metric tons), and secondary and micronutrient materials
(1.4 x 106 metric tons). The single nutrient fertilizers
include 12.1 x 106 metric tons of nitrogen materials,
2.1 x 106 metric tons of phosphate materials, 2.7 x 106
metric tons of potash materials, and 0.4 x 106 metric tons
of natural organics. Secondary and micronutrient materials
Commercial Fertilizers, Consumption in the United States,
Year Ended June 30, 1973. Statistical Reporting Service,
U.S. Department of Agriculture. Washington. Publication
No. SpCr 7 (5-74). 1974. 26 p.
13
-------
N REPRESENTS AVAILABLE NITROGEN
P REPRESENTSAVAILABLEP205
K REPRESENTS SOLUBLE K20
TOTAL
FERTILIZERS
DIRECT APPLICATION
FERTILIZERS
MIXED FERTILIZERS
N
K
SECONDARY AND
MICRONUTRIENTS
N
-P
-K
Figure 1. Types of fertilizers consumed in the U.S.
-------
DIRECT APPLICATION
MATERIALS
44.6%
V_ SECONDARY &MICRONUTRIENTS
3.4*
1.4 xlO6 METRIC TONS
Figure 2. Distribution of commercial fertilizers
consumed in the United States in 1973
are reported separately, but they are mixed with the primary
nutrients and mixed fertilizers prior to field application.
A mixed fertilizer is defined as a fertilizer containing more
than one of the primary plant nutrients: nitrogen, phos-
phate, and potash.2 The fertilizer grade is specified
according to its content of these nutrients and is usually
designated as an N-P-K mixture. For example, according to
the current reporting system the grade 11-37-10 indicates
a formulation in which 11% of the mixture is nitrogen, 37%
is available P20s, and 10% is soluble K20. All phosphate
containing materials are reported in terms of PaOs anc^ all
potash materials are reported as K2O. Other components in
the mixture include chemically combined carriers, i.e.,
sulfates, phosphates and calcium, and additional fillers and
conditioners. The average analysis of all mixed fertilizers
2Farm Chemicals Handbook - 1973, Dictionary of Plant Foods
Willoughby, Ohio, Meister Publishing Co., 1973. 64 p.
15
-------
for the 1973 fertilizer year was 10.19% nitrogen, 18.66%
and 12.78% K20, totaling 41.63% plant nutrients.
The consumption values for the four types of mixed fertilizer
(N-P-K, N-P. N-K, and P-K) are shown in Figure 3 in relation
to their shares of the 20.3 x 106 metric tons of 1973 mixed
fertilizer consumption. The majority (77.5%) is a mixture
containing all three primary plant nutrients.
Mixed fertilizers are produced by three distinctly different
types of production plants (Figure 4):
• Ammoniation-granulation
• Bulk blending
• Liquid mixing
0.37x10 METRIC TONS
1.0x10" METRIC TONS
Figure 3.
Proportion of mixed fertilizer grades
consumed in 1973
16
-------
AMMONIATION-
GRANULATION
PUGMILL
ROTARY
DRUM
MIXED
FERTILIZER
PRODUCTION
BULK BLEND ING
LIQUID MIXING
HOT MIX
COLD MIX
Figure 4. Three types of fertilizer mixing plants
-------
The ammoniation-granulation and bulk blending plants produce
a dry, granular fertilizer mixture, while liquid mixing
plants produce a liquid mixture. For comparison, a schematic
process flow diagram for each type of production plant is
shown in Figure 5.
Ammoniation-granulation plants chemically react liquid and
dry raw materials (such as ammonia, phosphoric acid, phos-
phate compounds, sulfuric acid, and potash) in a granulator
to produce a dry, granular mixed fertilizer. Each granule
produced by this method contains portions of all three
nutrients. The basic process differences among these plants
are the type of granulator used and the raw materials used
to produce the various grades of fertilizer.
Bulk blending plants physically mix dry fertilizer materials
such as diammonium phosphate, urea-ammonium nitrate, and
potash in a mixer to produce, without chemical reaction, a
dry, granular mixed fertilizer. These plants differ in types
of mixers and plant layout.
There are two types of liquid mixing plants—hot and cold
mix. Hot mix plants chemically react phosphoric acid, ammonia,
urea, and potash to produce a liquid mixed fertilizer. This
type of plant is termed "hot" mix because of the exothermic
reaction between ammonia and phosphoric acid. Cold mix
plants physically mix liquid materials in a mixer to produce
the desired liquid mixed fertilizer without a chemical
reaction.
According to the Fertilizer Division of the Tennessee Valley
Authority (TVA) at Muscle Shoals, Alabama, there were 195
ammoniation-granulation plants, 5,640 bulk blending plants,
and 2,768 liquid mixing plants in the U.S. in the 1973
18
-------
MATERIALS
STORAGE
i
AMMONIATOR-
GRANULATOR
DRYER AND
COOLER
SCREEN
PRODUCT
(a) AMMONIATION - GRANULATION
MATERIALS
STORAGE
MIXER
PRODUCT
(b) BULK BLEND ING
MATERIALS
STORAGE
REACTOR
MIXER
I
HEAT
PRODUCT
EXCHANGER
(OPTIONAL)
(c) LIQUID MIXING
Figure 5. Basic process flow diagrams for
fertilizer mixing plants
19
-------
fertilizer year.3'4 The total of 8,603 fertilizer mixing
plants in the U.S. should not vary by more than ±200 plants.
In terms of production, ammoniation-granulation plants (ex-
cluding diammonium phosphate plants) produce a majority (45%)
of the mixed fertilizers.5 Figure 6 gives 1973 production
figures for all three types of mixing plants.
AMMOWATION-GRANULATION PLANTS
9.14 xlO6 METRIC TONS
32%
BULK BLENDING PLANTS
6.50 xlO6 METRIC TONS
LIQUID MIX PLANTS
4.67 XlO" METRIC TONS
Figure 6. Fertilizer production by the three
types of mixing plants
3Private communications. N. L. Hargett. National Fertilizer
Development Center, TVA, Muscle Shoals, Alabama.
^Private communications. Dr. W. C. White. The Fertilizer
Institute, Washington, D.C.
5Harre, E. A., and J. N. Mahan. The Supply Outlook for
Blending Materials. In: TVA Fertilizer Bulk Blending
Conference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-62. August 1973. p. 9-21.
20
-------
Production statistics for the three types of fertilizer
mixing plants are given in Table 5. The total annual pro-
duction values for these plants were calculated based on
the market percentages shown in Figure 6. The values for
the annual production rates for individual plants reflect a
wide range of mixing plant sizes; from small, seasonal,
batch-type operations to large, yearly, continuous operations.
Since detailed plant production rates are not available, the
total annual production was divided by the number of plants
(e.g., [9.14 x 106 metric tons/year] v 195 plants = 46.9 x 103
metric tons/year) to calculate average plant production rates.
The size of a fertilizer mixing plant is expressed in terms
of its designed hourly production rate. A bulk blend plant,
for example, may have a production "capacity of 18 metric
tons/hr. However, due to the plant's batch-type operation,
it may only average 1.8 metric tons/hr. The average design
production capacity for ammoniation-granulation plants is
22.5 metric tons/hr, and for bulk blend and liquid mix plants
this value is 9 metric tons/hr to 18 metric tons/hr.
Due to the nature of the agricultural industry, fertilizer
mixing plants operate on a seasonal basis. The length of
the operating period depends on the geographical location of
the mixing plant and the crops being fertilized. In the South
the mixing season may last from 8 to 10 months/yr, while in
the northern states this season may only last 4 to 5 months/yr,
On a national basis, the peak operating periods for mixing
fertilizer are in the months of February to July and October
to December.
On a national average, ammoniation-granulation plants operate
12 hr/day, 5 days/week in January; 16 hr/day, 6 days/week
from February to May; 12 hr/day, 5 days/week from June to
21
-------
Table 5. PRODUCTION STATISTICS FOR FERTILIZER MIXING PLANTS IN 1973
Statistic
Number of plants
Total annual production,
106 metric tons
Annual plant production rate,
10 3 metric tons/yr
Average annual production rate,
10 3 metric tons/yr
Plant design hourly production rate,
metric tons/hr
Average annual operating period,
hr/yr
Actual average production rate,
metric tons/hr
Ammoniation-
granulation
195
9.14
9.0 to 90.0
46.9
9 to 45
3,216
14.57
Bulk blend
5,640
6.50
0.450 to 3.2
1.15
4.5 to 45
1,280
0.90
Liquid mix
2,768
4.67
0.450 to 2.3
1.69
9 to 45
1,280
1.32
to
to
-------
November; and are closed down in parts of November and
December for annual maintenance. The variation in operating
periods for bulk blend and liquid mix plants fluctuates
considerably across the nation because these plants supply
fertilizer to a small area (usually less than 93 km from
the plant). Therefore, their operating periods are dependent
on the crops planted and local weather conditions. On the
average, bulk blend and liquid mix plants operate 8 hr/day,
5 days/week, 8 months/yr.
Using the average operating periods and the average annual
production rates, the average hourly production rates were
calculated. These values, shown in Table 5, further illus-
trate the batch-type nature of mixing plant operation.
B. RAW MATERIALS
1. Primary Nutrients
The quantities of raw materials consumed by fertilizer mixing
plants in the U.S. as reported by the 1972 Census of Manufac-
tures6 (in Standard Industrial Classifications 2874 and 2875)
are shown in Table 6. Organic ammoniates listed in Table 6
include natural organic materials such as dried blood, castor
pomace, compost, cottonseed meal, dried manure, activated
sewage sludge, and tankage.
Due to the nature of the various raw materials reporting
systems and the complexity of the fertilizer industry, it
is not possible to extract the amount of raw materials used
by each of the three types of mixing plants (e.g., how much
diammonium phosphate is used by bulk blending or liquid mixing
°1972 Census of Manufactures, Preliminary Report. U.S.
Department of Commerce. Washington. Publication No.
MC 72(P)-28G-1, -2, and -3. January 1974. 12 p.
23
-------
Table 6. RAW MATERIALS CONSUMED BY
FERTILIZER MIXING PLANTS IN 19726
Material
Basis
Quantity, 103
metric tons
Nitrogenous material:
Ammonia, anhydrous
Ammoniating, or nitrogen solution
including mixtures containing
urea
Ammonium nitrate
Sodium nitrate
Ammonium sulfate
Urea and calurea
Other nitrogenous materials,
including potassium nitrate,
calcium cyanamide, ammonium
nitrate and limestone mixtures
Organic ammoniates
Phosphatic materials:
Normal superphosphate (<20% P20s)
Concentrated superphosphate
(<40% P205)
Other phosphatic materials,
including wet base goods,
ammonium phosphates, etc.
Potassic materials:
Muriate of potash
Other potash bearing material
Inert fillers and secondary
plant food
Sulfuric acid
Phosphoric acid
100% NH3
100% N
100% NH^N03
100% NaN03
100%
100% N
100% N
100% N
100% P205
100% P205
100% P205
60-62% K20
1,768.7
487.3
324.9
12.0
664.0
102.6
122.7
92.7
540
1,440
402.8
100%
100% P2O5
2,439.6
309.0
1,070.4
810
720
24
-------
plants). However, the following materials are used only by
ammoniation-granulation plants and hot mix liquid mixing
plants: anhydrous ammonia, sulfuric acid, and phosphoric
acid. Therefore, based on the production values of these
plants, ammoniation-granulation plants consume 84% of these
three raw materials and hot mix liquid mixing plants con-
sume 16%.
2. Secondary and Micronutrient Materials
In addition to the primary nutrients, secondary and micro-
nutrients are added to mixed fertilizers when requested by
the user. The U.S. Department of Agriculture reported that
1.18 x 106 metric tons of secondary and micronutrient ferti-
lizer materials were consumed in the U.S. in 1972. 1 This
value compares favorably with the 1.07 x 106 metric tons of
inert fillers and secondary plant food reported by the 1972
Census of Manufactures. The types and quantities of mater-
ials consumed are shown in Table 7. It is not possible to
determine the exact quantities of these materials that are
actually mixed with mixed fertilizers and with the direct
application materials. Therefore, the total consumption
value serves as an upper limit for the quantity of secondary
and micronutrients added to mixed fertilizers. If all of
these materials were added to mixed fertilizers, they would
constitute 5.5% of the total bulk weight. However, if one
subtracts the 887 x 103 metric tons of calcium sulfate
(gypsum) used as direct application material in California as
a source of sulfur and calcium, the secondary and micronutrient
materials would be 1.4% of the mixed fertilizer.
The secondary and micronutrient compounds consist of inor-
ganic sulfate and oxide compounds and organic chelating
compounds. The principal inorganic and organic forms of the
25
-------
Table 7. QUANTITIES OF SECONDARY AND MICRONUTRIENT
FERTILIZER MATERIALS CONSUMED IN THE U.S. IN 1972l
Material
Aluminum compounds
Boron compounds
Calcium sulfate (gypsum)
Copper compounds
Iron compounds
Magnesium compounds
Manganese compounds
Sulfur
Zinc compounds
Other
Total
Quantity,
metric tons
139
4,495
1,076,464
513
9,300
1,352
3,137
25,361
20,681
41,232
1,182,675
California alone consumes 887,585 metric
tons as direct application material.
micronutrients and their applicability to the different
types of mixed fertilizers are shown in Tables 8 and 9.
Chelating agents are added to the micronutrient mixtures to
keep the trace metals in a soluble form. Among the best
chelating agents are ethylenediaminetetraacetic acid (EDTA),
hydroxyethylenediaminetriacetic acid (HEDTA), and diethylene-
triaminepentaacetic acid (DTPA)-1
3.
Pesticides
In the past few years there has been a growing trend toward
applying pesticides, particularly herbicides, along with
26
-------
Table 8. PRINCIPAL INORGANIC FORMS OF MICRONUTRIENTS7
to
Nutrient
element
Boron
Chlorine
Copper
Iron
Manganese
Zinc
Common or
trade name
Fertilizer
Borate 48
Tronabor
Traco borate
Fertilizer
borate 68
Boro spray
solubor
Frit 237G
Frit 237
Muriate of
potash
Copper sulfate
or blue
vitriol
Copper oxide
Frit 177G
Frit 177
Iron sulfate
Iron carbonate
Frit 227G
Frit 227
Manganese
sulfate
Manganese oxide
Frit 187G
Frit 187
Zinc sulfate
Zinc oxide
Zinc-Ite
Frit 247G
Frit 247
Chemical name
Sodium tetraborate
Sodium pentaborate
Boron-phosphate
Frit
Potassium chloride
Cupric sulfate
Cupric oxide
Copper-phosphate
Frit
Ferric or ferrous
sulfate
Ferric or ferrous
carbonate
Iron-phosphate
Frit
Manganese sulfate
Manganous oxide
Manganese-phosphate
Frit
Zinc sulfate
Zinc oxide
Zinc oxide
Zinc-phosphate
Frit
General
chemical formula
Na2BMO7-5H2O
Na2B,07
Na2B10016.nH20
(Amorphous)
KC1
CuSOi, • 5H2O
CuSOi('H2O
CuO
(Amorphous )
Fex(S01)) -nH20
Fex(C03)y
(Amorphous )
MnSOi, • nH2O
MnO
(Amorphous)
ZnSOi, • nH20
ZnO
ZnO
(Amorphous)
Elemental
14-15
21-22
18-19
20-21
10
47-48
25-26
35-36
75-90
40
18-24
40-50
40
23-28
41-62
28
35
18-37
57-58
25% Zn
28-40
Material
form
Granular
or powder
Granular
Powder
Powder
Granular
Powder
Granular
Granular
Powder
Powder
Granular
Powder
Granular
or powder
Granular •
or powder
Granular
Powder
Granular
or powder
Granular
or powder
Granular
Powder
Granular
or powder
Powder
Granular
Granular
Powder
Use best adapted to
Blend
solid
X
X
X
X
X
X
X
X
X
X
X
X
xa
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Liquid
suspension
X
X
X
X
X
X
xa
x*1
X
X
X
X
X
X
X
Clear
liquids
X
X
X
X
X
X
X
Ammon.
gran.
X
X
X
X
X
X
X
X
xa
xa
X
X
X
X
X
X
X
Foliar
in water
X
X
•
X
X
X
Generally, iron is not effectively taken up by the plant when applied with fertilizer in the soil.
'curlcy, R. D., and M. C. Sparr. Systems for Supplying Micronu .lents. In: TVA Fertilizer
Conference. Tennessee Valley Authority. Muscle Shoals, Alabama. Bulletin Y-78. August
1974. p. 46-54.
-------
Table 9. PRINCIPAL ORGANIC FORMS OF MICRONUTRIENTS7
Element
Copper
Iron
Manganese
Zinc
Chelate or
complex
EOT A
EDTA
DTPA
Polyflavonoid
Lignosulfonate
Rhizochyme
EDTA
EDTA
HEEDTA
HEEDTA
HEEDTA
DTPA
EDDHA
Palyflavonoid
Lignosulfonate
Lignosulfonate
Rhizochyme
EDTA
EDTA
HEEDTA
HEEDTA
Polyflavonoid
Lignosulfonate
Rhizochyme
EDTA
EDTA
DTPA
Polyflavonoid
Lignosulfonate
Lignosulfonate
Rhizochyme
Elemental %
7.5
13.0
5.098
6.7
5-6
6.0
14.0
5-8
5.0
9.0
5.0
10.0
6.0
9.6
5-6
11.0
6.0
5.0
12.0
5.0
9.0
8.5
5-7
7.0
6-9
14.5
6-10
10.0
7.0
14.0
7.0
Material
form
Liquid
Powder
Liquid
Powder
Powder
Liquid
Powder
Granule
Liquid
Powder
Granule
Powder
Powder
Powder
Powder
Granule
Liquid
Liquid
Powder
Liquid
Powder
Powder
Powder
Liquid
Liquid
Powder
Liquid
Powder
Powder
Granular
Liquid
Best adapted
soils
neutral to
Acid
Acid
Alkaline
-
-
—
Acid
Acid
Acid
Acid
Acid
Alkaline
Alkaline
-
-
-
—
Acid
Acid
Acid
Acid
-
-
—
Acid
Acid
Alkaline
-
—
—
"
Use best adapted to
Blend
or coat
solid
X
X
X
X
X
a
xa
a
X
X
Liquid
suspehsion
X
X
X
X
X
X
Clear
liquids
X
X
X
X
X
X
X
X
Foliar
in water
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
00
'Agronomic effectiveness may be nil on soils containing high soluble iron content
-------
fertilizers.9 This application technique reduces the number
of trips a farmer has to make over his crops, thus reducing
operating costs and labor expenses. For example, one midwest
farm service charges 0.037 cents/m2 ($1.50/acre) to custom
apply fertilizers and 0.049 cents/m2 ($2.00/acre) to custom
apply straight pesticide. However, the service makes no
additional charge for mixing a herbicide with the fertilizer
and applying them jointly, resulting in a cost of 0.037 cents/m2
($1.50/acre) as compared to 0.086 cents/m2 ($3.50/acre).8
Pesticide is an all-inclusive term covering fungicides,
herbicides, insecticides, miticides, defoliants, rodenti-
cides, and repellents.10 However, only herbicides are mixed
with fertilizers for joint crop application. Liquid mix
plants have added herbicides to their fertilizers longer
than other mixing plants because it is easier for them to
mix the two components and insure a homogeneous solution.
Approximately 80% of the liquid mix plants add herbicides.8
Bulk blend plants have more difficulty in applying herbicides
to their mixtures. Successful approaches to the problem
include impregnating and coating the dry fertilizer with
herbicide solutions. Only about 30% of the bulk blend plants
add herbicides to their mixed fertilizers. Ammoniation-
granulation plants usually (<1% of tonnage) do not add
herbicides to their mixtures.
Estimated amounts of herbicides mixed with fertilizers in
1971 are shown in Table 10. Since these values are not
8Feed and Weed. Special Report. Farm Chemicals, 1974.
31 p.
9Private communications. H. L. Balay. National Fertilizer
Development Center, TVA, Muscle Shoals, Alabama.
10Farm Chemicals Handbook - 1973, Pesticide Dictionary.
Willoughby, Ohio, Meister Publishing Co., 1973. 191 p.
29
-------
Table 10. ESTIMATED QUANTITIES OF SELECTED HERBICIDES
(ACTIVE INGREDIENTS) APPLIED TO CROPS WITH MIXED FERTILIZERS11
Type of herbicide
Inorganic herbicides
Organic herbicides:
Arsenicals
Phenoxys:
2,4-D
2,4,5-T
MCPA
Other phenoxy
Total
Phynyl urea:
Diuron
Linuron
Fluometuron
Other phenyl urea
Total
Amides:
Propachlor
Propanil
Ana lap
Alachlor
Other amides
Total
Carbamates:
EPTC
Pebulate
Vernolate
Butylate
Other carbamates
Total
Dinitro group
Triazines:
Atrazine
Propazine
Simazine
Other triazines
Total
Benzoics:
Amiben
Dicamba
Other benzoic
Total
Other organics:
Trifluralin
Nitralin
Dalapon
Norea
Fluorodifen
Others
Total
Total organic herbicides
(excluding petroleum)
Total herbicides
(excluding petroleum)
Petroleum
Total herbicides
Quantity applied with mixed
fertilizer, metric tons/yr
196
924
3,922
158
387
71
4,538
145
213
393
31
781
2,799
785
393
1,740
94_
5,811
520
125
441
698
379
2,163
848
6,748
374
203
170
7,495
1,127
50
14
1,191
1,348
319
122
156
157
566
2,667
24,417
24,613
16,835
43,448
30
-------
compiled and reported in the literature, an upper limit was
calculated based on the following assumptions:
• U.S.D.A. total 1971 herbicide consumption values
for crop application were used as a base;11
• 50% of these herbicides were applied with
fertilizers;
• 52% of the above quantity of herbicides were
applied with mixed fertilizers (based on the
ratio of mixed fertilizers to total fertilizer);
and
• 75% of the value in the third assumption was
applied with liquid mixed fertilizers and 25%
was applied to bulk blended fertilizers.
The July 1974 U.S.D.A. publication entitled, "Farmer's Use
of Pesticides in 1971"ll , is the most current and best
available source of information concerning the distribution
of pesticides in the U.S.
The geographical distribution of 1971 U.S. herbicide con-
sumption is shown in Figure 7- The herbicide product used
most by farmers in 1971 was atrazine, accounting for 25% of
all herbicides used. Atrazine is used for season-long weed
control in corn, sorghum, and certain other crops. Other
major herbicides include 2,4-D (15%) and propachlor (11%).
These herbicides are used to control weeds in cereal and
broadleaf crops. In 1974 EPA banned the use of 2,4-D. The
majority (>80%) of the herbicides mixed with fertilizers
are applied as pre-emergence herbicides, as opposed to
post-emergence herbicides.8
1 farmers' Use of Pesticides in 1971. U.S. Department
of Agriculture. Washington. Agriculture Economic Report
No. 252. July 1974. 56 p.
31
-------
OJ
to
NORTHERN
PLAINS
SOUTHERN
PLAINS
Figure 7. Geographical distribution of herbicides applied to crops in 1971
-------
C. AMMONIATION-GRANULATION PLANTS
1. Process Description
In 1973, ammoniation-granulation mixing plants produced 45%
(9.14 x 106 metric tons) of all mixed fertilizers consumed
in the U.S. The 195 ammoniation-granulation plants represent
2.3% of the total number of fertilizer mixing plants in the
country. They have the largest production capacities of all
mix plants, ranging from 9 to 90 x 103 metric tons/yr, and
the average production rate per plant is 46.9 x 103 metric
tons/yr. The majority (56%) of these mixing plants are lo-
cated in the grain belt states of Illinois, Indiana, Iowa,
Minnesota, Missouri, Nebraska, and Ohio, and in the phosphate
rock mining states of Alabama, Georgia, and Florida (Figure 8)
The earliest process for making a homogeneous, granular,
mixed fertilizer involved wetting a mixture of solid plant
nutrient materials with sufficient water to cause the for-
mation of granules.12 Ammonium sulfate, phosphate rock, and
potassium chloride were the staple raw materials. By the
early 1950's, more concentrated fertilizers were produced
by replacing ammonium sulfate with ammonium nitrate and
superphosphates with ammonium phosphate slurries. The wider
range of raw materials used later included ammoniating solu-
tions, ammoniated superphosphates, calcium metaphosphates
and phosphate slurries. Today, ammoniation (the chemical
combination of free ammonia with phosphoric acid) is prac-
ticed in conjunction with granulation.13 The exothermic
12Chemistry and Technology of Fertilizers. V. Sauchelli (ed.)
New York, Reinhold Publishing Corp., 1960. 424 p.
1 Q
Shreve, R. N. Chemical Process Industries, 3rd Edition.
New York, McGraw-Hill Book Co., 1967. 489 p.
33
-------
00
Figure 8. Geographical distribution of ammoniation-granulation
mixing plants in 1973
-------
heat of reaction due to ammoniation serves to increase
chemical reactions, granulation, and moisture vaporization.
This procedure results in a more concentrated fertilizer and
requires less water.
Superphosphoric acid, a term used to define a range of
mixtures of ortho- and polyphosphoric acids, is anhydrous
and reacts with ammonia and other materials to form soluble
salts that increase the liquid phase in the granulator with
the addition of a minimum amount of water.14 The two basic
salts are mono- and diammonium phosphate which are produced
in the granulator by the following reactions, depending on
the amount of ammonia added : 1 5
H3PO4 + NH3 -»• (NHit)H2POlf (D
H3PC\ + 2NH3 -> (NHif)2HPO4 (2)
A generalized flow diagram of a fertilizer ammoniation-
granulation plant is shown in Figure 9. The process consists
of five basic stages:
Stage 1. Mixing - where the raw solid materials are mixed
and screened to the proper size range, about
1 mm to 4 mm in diameter.
Stage 2. Ammoniation-granulation - where the physical
mixing and chemical reactions of raw feeds with
recycled material occur to form a granular
fertilizer.
Stage 3. Drying - where surplus moisture is removed to a
level dictated by the storage properties of the
fertilizer, around 1.8%.
^Achorn, F. P., and H. L. Balay. Phosphoric Acid: Shipment,
Storage, and Use in Fertilizers. Fertilizer Solutions
Magazine. 17(5), September-October 1973.
lr'Slack, A. V. Fertilizer Developments and Trends - 1968.
Park Ridge, New Jersey, Noyes Development Corp., 1968. 405 p
35
-------
RAW
SOLID -"
MATERIALS
w
EMISSIONS
I
SOLIDS
MIXING
EMISSIONS
*
SCREENS
*— .».
i
UKUillllMb
^ MILL
EMISSIONS
A EMISSIONS
L A EMISSIONS
fc-AMMONIATOR- I — J, i
1 [GRANULATOR — *^ DRYER L P — ^~~^i
I 1 j^j^^ ^ COOLER _
LIQUID " L___^
RAW
MATERIAL
EMISSIONS
f
CRUSHINGL
MILL |
EMISSIONS
I
DOUBLE DECK
SCREEN
1
PRODUCT
FINES AND RECYCLE
Figure 9. Generalized flow diagram of an
ammoniation-granulation fertilizer plant
-------
Stage 4. Cooling - where the fertilizer is cooled to
ambient temperature without adding moisture.
Stage 5. Classification - where the dried material is
screened to the desired size range, 1 mm to
4 mm in diameter. The oversize is crushed
and returned to the screen. The undersize is
returned to the ammoniator-granulator.
The presence of a recycle in the generalized manufacturing
process results from the inability of the granulation pro-
cess to produce all the granules within the desired product
size range (i.e., 1 mm to 4 mm).
The primary purpose of the ammoniation-granulation mixer is
to agitate the bed of solids to ensure adequate mixing of
the solid and liquid phases and to .promote the particle to
particle collisions necessary for granule growth. There are
four basic mixer designs used by ammoniation-granulation
mixing plants:
• Pan granulator
• Batch-mix ammoniator
• Pugmill ammoniator
• Rotary-drum ammoniator
The TVA has the only pan granulator in use today, which is
used primarily for research production.16 It is estimated
that batch-mix ammoniators are used for less than 1% of the
total production of mixed fertilizers.9 These two types of
mixing plants are therefore omitted from the detailed pro-
cess discussion and from further individual consideration.
bPrivate communications. E. A. Harre. National Fertilizer
Development Center, TVA, Muscle Shoals, Alabama.
37
-------
2. Pugmill Anunoniator
A pugmill is comprised of a U-shaped trough carrying twin
contrarotating shafts upon which are mounted strong blades
or paddles. The action of the paddles agitates, shears, and
kneads the solid-liquid mix, and transports the material
along the trough. Solid raw materials and recycled fines
are fed to the inlet end of the pugmill and the liquids are
injected under the bed.17
Granulation occurs, or at least starts, in the pugmill and
is controlled by the formulation, by the recycling rate of
the fines, or by the addition of water. Additional granu-
lation occurs in the dryer. From the dryer the product
passes into a cooler and then to a double-deck screen. The
oversize (>4 mm) is crushed and returned to the screen while
the fines (<1 mm) are recycled to the pugmill.
It is estimated that pugmill ammoniator mixing plants are
used in less than 5% of the total production of mixed
fertilizers in the U.S.3'9 In addition, pugmill sources of
emissions and emission characteristics are the same as those
from rotary-drum ammoniation mixing plants. Therefore, only
the rotary-drum ammoniation-granulation fertilizer mixing
plants will be discussed in detail.
3. Rotary-Drum Ammoniator-Granulator
The majority (approximately 95%) of the ammoniation-granulation
plants in the U.S. use the rotary-drum mixer of the type
17Powell, T. E. Granulation in the Fertilizer Industry.
Process Technology International, 18:271-278, June-July
1973.
38
-------
developed and patented by the TVA.9'18 The basic rotary-
drum ammoniator, Figure 10, consists of an open end, slightly
inclined rotary cylinder, with retaining rings at each end
and a scraper or cutter mounted inside the drum shell. The
drums vary in diameter from 2 m to 3 m and in length from
3 m to 6 m. A rolling bed of solid material is maintained
in the unit while the liquids (such as ammonia and sulfuric
acid) are introduced through horizontal, multioutlet dis-
tributor pipes set lengthwise of the drum under the bed.
The process flow diagram of a rotary-drum ammoniation-
granulation mixing plant with typical emission controls is
shown in Figure 11. Solid nutrient materials such as normal
superphosphate, triple superphosphate and potash are weighed,
mixed, and added to the mixer in exact proportions. Liquid
solutions of ammonia, phosphoric acid, and water are added
to the bed of solids in the mixer. Granulation occurs in
the rotary drum and finishes in the dryer. The temperature
of the granular fertilizer in the rotary drum reaches 85°C
to 105°C while the temperature of the off-gases from the
rotary drum reaches 38°C to 77°C. The temperature of the
off-gases from the dryer ranges from 93°C to 104°C and from
the cooler, from 4°C to 27°C. The granular mixed fertilizer
then passes to the screen system. A double-deck screen is
used to separate the oversized (>4 mm), product-sized (1 mm
to 4 mm), and undersized (<1 mm) particles (fines). The
oversized particles are crushed and recirculated back to
the screen. The undersized particles are recycled back to
the ammoniator-granulator. The finished product is either
stored, bagged, or bulk loaded into trucks.
1 P
1CPrivate communications. J. C. Barber. National Ferti-
lizer Development Center, TVA, Muscle Shoals, Alabama.
39
-------
SOLID MATER.AL
SLURRY
Figure 10. TVA continuous ammoniator-granulator
-------
Figure 11. Conventional ammoniation-granulation plant
with a rotary-drum ammoniatorlk
-------
The rotary-drum mixer produces a more rounded, less dense
product than the pugmill. However, successful operation
depends upon the efficiency of the liquid distributors.
Poor granulation results from incorrect siting of liquor
spray nozzles. Submerged acid spargers, made from black
iron or stainless steel, are subject to corrosion, partic-
ularly when used with chloride-containing formulations.
Poor mixing of the bed produces high ammonia losses and
localized heats of reaction which can result in flash fires.
4.
Raw Materials
The types of raw materials consumed by ammoniation-granulation
plants are shown in Table 11. The formulation for mixed
fertilizers varies from plant to plant. For example, sul-
furic acid can be used instead of phosphoric acid for ammoni-
ation. Therefore, one plant that produces a mixed grade of
12-12-12 will not necessarily use the same raw materials as
another plant producing the same grade. The types and amounts
of raw materials that can be used to produce a 12-12-12 grade
of mixed fertilizer by an ammoniation-granulation plant are
shown in Table 12.
Table 11. TYPES OF RAW MATERIALS CONSUMED
BY AMMONIATION-GRANULATION PLANTS
Material
Formula or description
Ammonia, anhydrous
Ammonium sulfate
Ammonium nitrate
Urea
Normal superphosphate, <20%
Triple superphosphate, ^40% P205
Phosphoric acid
Potash
Sulfuric acid
Filler
NH3
(NHtt)2SOtf
NH2CONH2
H3POlt
KC1
sand, limestone
42
-------
Table 12. FORMULATION DATA FOR AN
AMMONIATION-GRANULATION PLANT19
(12-12-12 grade, 13.6 metric tons/hr production rate)
Formulation,
g/kg of product
Anhydrous ammonia
Ammonium sulfate (21% N)
Normal superphosphate
Triple superphosphate
Wet process phosphoric acid
(54% P205)
Superphosphoric acid
(76% P205)
Sulfuric acid (94% H2S04)
Hi-grade (42% P205)
Potash (60.5% K2O)
Filler (sand)
Filler (1/3 limestone, 2/3 sand)
Mixture
1
120
125
0
0
170
0
280
75
194
67
0
2
151
0
225
0
145
0
345
0
199
0
0
3
39
428
0
53
75
75
0
0
200
143
0
4
43
410
0
0
155
50
0
0
200
0
157
Ammoniation-granulation plants can incorporate secondary
and micronutrients into the granulation process. Only
inorganic forms of micronutrients can be used, however,
because the organic chelates will decompose at the elevated
process temperatures (65°C to 82°C).7 The quantities of
such materials consumed at these mixing plants cannot be
determined. However, Table 8 indicated the types of micro-
nutrients that can be used by ammoniation-granulation
plants.
19Achorn, F. P., and J. S. Lewis,. Jr. Equipment to Control
Pollution from Fertilizer Plants. Agricultural Chemicals
and Commercial Fertilizer. 27, February 1972.
43
-------
5. Emission Sources
Emissions at aramoniation-granulation plants come from five
process steps:
• Materials storage and handling
• Ammoniator-granulator
• Dryer and cooler
• Screen and oversize mill
• Bagging and loading
Fugitive dust consisting of the raw materials is emitted
from the cluster hoppers, weighing hoppers, bucket elevators,
and recycling conveyors.
Pollutant species generally emitted from the ammoniator-
granulator include:
• Ammonia vapor and ammonium salts
• Chloride salts
• Fluorine compounds
• Phosphorus compounds
• Sulfur compounds
• Particulates
Ammonia related emissions include NH3 vapor, NH^Cl,
(NH^)2HPOj+, and (NHi^^SOtj. Chlorine related emissions,
due to the addition of potash, include chlorine vapor and
inorganic salts, such as NH4C1 and KC1. Fluoride emissions
are a result of trace quantities (1% to 2%) of inorganic
fluoride salts (e.g., CaF2) in the phosphoric acid, normal
and triple superphosphate, and filler material (e.g., sand)-20
20Robinson, J. M., et al. Engineering and Cost Effectiveness
Study of Fluoride Emissions Control, Vol. I. U.S. Environ-
mental Protection Agency, Office of Air Programs. Washington,
PB 207506. January 1972.
44
-------
Emissions of fluorine will be in the form of CaF2, SiFi4 and
HF. Phosphorus emissions, reported as total phosphorus, are
emitted in the particulate form and consist of Ca3(POlt)2/
(NHi4) 2HP°it f H3POI+, and K2HP03.21 Sulfur emissions are in
the form of inorganic sulfate salts such as CaSO^ and K2S(\.
However, due to the completeness of the ammoniation reaction
with I^SO^,18'22 these emissions are usually low (<0.1% of
total) and therefore will be included with general particu-
late emissions.
Ammonium chloride aerosols are formed in the ammoniator-
granulator when sulfuric acid reacts with potassium chloride
(potash) to form hydrogen chloride which, in turn, reacts
with gaseous ammonia. Emissions of ammonium chloride are of
particular interest at these mixing plants because their
small particle size (0.1 ym to 5 ym) dictates the use of
expensive high efficiency (>99%) control equipment. In
addition, these aerosols produce a very visible/ dense, white
plume (>70% opacity) which may exceed local state opacity
regulations.19
Emission species from the dryer and cooler will be the same
as from the ammoniator-granulator, namely ammonia, chlorine
compounds, fluorine compounds, phosphorus compounds, and
particulates. Dryer and cooler gas flow rates range from
280 to 560 m3/min, with an average value of 370 m3/min.
21National Emissions Inventory of Sources and Emissions of
Phosphorus. U.S. Environmental Protection Agency. Wash-
ington. Publication No. EPA-450/3-74/013. May 1973. 54 p.
00
''Private communications. F. P. Achorn. National Fertilizer
Development Center, TVA, Muscle Shoals, Alabama.
45
-------
D. BULK BLENDING PLANTS
1. Process Description
Bulk blending fertilizer mixing plants produced 32%
(6.50 x 106 metric tons) of the mixed fertilizers consumed
in the U.S. in 1973. This type of mixing plant is much
smaller, both in land area and production rate, than the
ammoniation-granulation mixing plant. The annual production
rates for bulk blending plants range from 450 metric tons/yr
to 3,200 metric tons/yr with an average production value of
1,150 metric tons/yr. The hourly production rate varies
from 4 metric tons/hr to 45 metric tons/hr, and average plant
capacity is 18 metric tons/hr. Based on actual production
values, bulk blending plants produce, on the average, 0.90
metric tons/hr. The peak season (75% of production) for
producing bulk blended fertilizers is between January and
June. The second most active production period (25% of
production) is between July and November.
In 1973 there were 5,640 bulk blending plants in the U.S.,
representing 65.5% of all types of fertilizer mixing plants.
The major concentration (57%) of the bulk blending plants is
in the states of Illinois, Indiana, Iowa, Missouri, Ohio,
Minnesota, and Wisconsin (Figure 12).
Bulk blending is defined as the physical mixing, without
chemical reaction, of granular single nutrient and multi-
nutrient materials to produce a dry fertilizer mixture.2
A common plant layout is shown in Figure 13.23 The basic
differences between fertilizer bulk blending plants are
23Achorn, F. P., and J. C. Barber. Bulk Blender Equipment,
Fertilizer Progress. 3_(6) , November-December 1972.
46
-------
57
Figure 12. Geographical distribution of fertilizer bulk blending plants in 1973
-------
EMISSIONS
EMISSIONS
EMISSIONS
Figure 13. Bulk blending plant with a ground
level rotary mixer23
48
-------
their plant layout and type of mixer used. Conveyors
transport raw materials from hopper-bottom railway cars to
a distribution system.
Shuttle conveyors, bucket elevators, or pneumatic conveyor
systems are used to transfer the raw material from the screw
conveyor to the storage bins. The storage bins are located
inside the building which houses the mixing plant. All of
the mixing and bagging facilities are also located inside
the building to avoid degradation of the fertilizer, raw
materials, and equipment due to inclement weather. The
granular raw materials are removed from bulk storage by a
front-end loader or a sweep auger which dumps them into the
feed hopper of a bucket elevator or directly into the mixer
hopper. The bucket elevator then transfers the material to
the weighing hoppers located just above the mixer.
Specific amounts of raw materials are weighed and gravity-
fed into the mixer. The granular mixed fertilizer then
flows by gravity to another bucket elevator which dumps it
into a surge tank for storage. The mixed fertilizer is then
loaded directly into a truck or bagged for shipment.
2. Types of Mixers
One major difference between bulk blending plants is the
type of mixer used. There are several types of blending
mixer designs.23 Table 13 shows the results of a survey of
mixer types taken in 1968, which indicated that 64% of the
mixers were of the rotary-drum type.15 Today, the trend is
toward this type of mixer because of its versatility, con-
tinuous operation, and ability to produce a more uniformly
mixed fertilizer.2
49
-------
Table 13. SURVEY OF BULK BLENDING MIXER TYPES15
Type
Rotary drum
Concrete mixer
Volumetric
Screw mixer
Gravity mixer
Other
Total
Percent
37
27
14
10
8
4
100
The type of rotary mixer installed at bulk blending plants
has an inclined axis. The typical concrete mixer used on
trucks to deliver ready-mix concrete is an example of this
type. The reversible drive on these mixers allows them to
rotate in one direction for mixing and in the opposite
direction for discharging. The feeding and discharging
mechanism is the basic difference between the concrete
mixer design and the rotary-drum mixer. The dry materials
are fed into the rotary-drum mixer from one end and the mixed
product is discharged from the other end. During the mixing
process the ends are closed. About two-thirds of the mixers
used by bulk blenders are of these two types.
Rotary-drum mixers are easily modified to include a sprayer
system to spray binding agents, such as oil and liquid
fertilizer (diammonium phosphate:10-34-0), on the fertilizer
in order to reduce the dustiness of the granular fertilizer
(thus reducing fugitive dust emissions [Figure 14]).2lf'25
24Achorn, F. P., and H. L. Balay. Plant Experiences in Adding
Pesticides, Micro and Secondary Nutrients to Bulk Blends.
In: TVA Fertilizer Conference. Tennessee Valley Authority.
Muscle Shoals, Alabama. Bulletin Y-62. August 1973. p. 70-79,
25Achorn, F. P., and W. C. Brummitt. Different Methods of
Adding Pesticides to Bulk Blends. Fertilizer Progress.
4^9-10, March-April 1973.
50
-------
The same system can also be used to apply secondary and
micronutrient materials. To date/ there are no estimates as
to how many rotary-drum mixers are equipped with sprayer
systems.
The screw or ribbon type mixer blends the materials by the
action of a rotating shaft. The mixing materials are
dropped into the mixer from the top, mixed, then discharged
from the bottom.
3. Raw Materials
Bulk blended fertilizers are produced from single and multi-
nutrient dry. granular raw materials. Examples of single
nutrient materials include normal and triple superphosphate,
ammonium sulfate, urea, and potash. Examples of multi-
nutrient materials include mono- and diammonium phosphate
and potassium nitrate. Appendix A lists the raw materials
(and their particle size distributions) consumed by bulk
blending plants in 1972. Due to the nature of the materials
flow reporting system in the fertilizer industry, it is not
possible to determine the quantities of raw materials
consumed at these plants.
Bulk blending plants account for 25% of the herbicides
applied to mixed fertilizers. Estimates of the maximum
quantities used are shown in Table 14 and are based on 25%
of the values shown in Table 10. Approximately 30% (1,692
plants) of the bulk blending plants mix these herbicides with
the fertilizers.3
4. Emission Sources
All of the emissions from bulk blending plants are in the
form of particulates because these plants mix only dry,
51
-------
1.89 m3
(500 GAL),
LIQUID I
TANK
IQUID BINDING
AGENT
2 SPRAY NOZZLES
TEE JET
RECIRCULATION
VALVE
SUPPLY VALVE
PRESSURE
GAGE
CENTRIFUGAL PUMP
Figure 14. Spray system for coating
granules in rotary mixer26
26Achorn/ F. P., and H. L. Balay. Systems for Controlling
Dust in Fertilizer Plants. In: TVA Fertilizer Conference,
Tennessee Valley Authority. Muscle Shoals, Alabama.
Bulletin Y-78. August 1974. p. 55-62.
52
-------
Table 14. ESTIMATED QUANTITIES OF SELECTED HERBICIDES
(ACTIVE INGREDIENTS) USED BY BULK BLEND PLANTS, 1971
Type of herbicide
Quantity used,
metric tons/yr
Inorganic herbicides
Organic herbicides: ,
Arsenicals
Phenoxys:
2,4-D
2,4,5-T
MCPA
Other phenoxy
Total
Phenyl urea:
Diuron
Linuron
Fluometuron
Other phenyl urea
Total
Amides:
Propachlor
Propanil
Alanap
Alachlor
Other amides
Total
Carbamates:
EPTC
Pebulate
Vernolate
Butylate
Other carbamates
Total
Dinitro Group
Triazines:
Atrazine
Propazine
Simazine
Other triazines
Total
Benzoics:
Amiben
Dicamba
Other benzoics
Total
Other organics:
Trifluralin
Nitralin
Dalapon
Norea
Fluorodifen
Others
Total
Total organic herbicides
(excluding petroleum)
Total herbicides (excluding
petroleum)
Petroleum
Total herbicides
50
230
210
1,700
100
50
40
1,880
280
10
10
300
340
80
30
40
40
140
670
6,600
53
-------
granular material at ambient temperatures to produce a mixed
fertilizer. The composition of these particulates depends
on the raw materials used. Three process steps are sources
of emissions to the atmosphere at these plants:
• Material storage and handling
• Loading operations
• Fugitive building emissions
Material transfer systems responsible for particulate emis-
sions are screw conveyors, front-end loaders, bucket elevators,
rotary distributors which fill the weighing hoppers, con-
veyor belts, and pneumatic transfer systems. When pneumatic
transfer systems are used, the cyclone collectors that
separate the air from the material are another source
of emissions. Experts at the fertilizer division of TVA
state that very few (less than 1% of the plants, as an upper
limit) bulk blending plants use pneumatic material transfer
systems.9'22 In fact, these experts state that the majority
(greater than 90%) of the bulk blending plants have not been
required to install pollution control equipment because their
emissions have been below local state emission standards.
Loading bulk fertilizer into open trucks is the major
contributor (75.0%) to atmospheric emissions at bulk blending
plants. The majority (>50%) of the bulk blending plants use
a hopper-type loading station similar to the one in Figure 15.
Fugitive dust emissions issuing from the doors and windows
are a result of mixing and material transfer operations
within the building. Bagging machines within the building
also create dust emissions which escape into the ambient air
outside the building. Emissions as great as 9 g of dust
54
-------
k-WOOD
CLAM SHELL GATE
Figure 15. Bulk loading station with elevated
storage used in bulk blending
55
-------
per kg of fertilizer bagged have been reported in bagging
room atmospheres.2 7
E. LIQUID MIX PLANTS
1. Process Description
In 1973 liquid mixing fertilizer plants produced 23% (4.67 x
106 metric tons) of the mixed fertilizers consumed in the U.S
These plants have an annual production rate ranging from 450
metric tons/yr to 2,300 metric tons/yr, with an average pro-
duction value of 1,690 metric tons/yr.
There were 2,768 liquid mixing plants in the U.S. in 1973,
which represents 32.2% of all types of mixing plants. The
geographical distribution of liquid mixing plants is shown
in Figure 16. The majority (55%) of these plants are
located in the states of Illinois, Indiana, Iowa, Missouri,
Kansas, and Texas.
Liquid mixed fertilizers could well be called ammonium
phosphate solutions since ammonium phosphate is the only
soluble phosphate generally available and suitable for
supplying the phosphate requirements.28 When the N/P2O5
ratio needed is higher than that supplied by ammonium
phosphate, urea-ammonium nitrate solutions are added to
supply the supplemental nitrogen.29 The ammonium phosphate
27Barber, J. C. Environmental Control in Bulk Blending Plants
1. Control of Air Emissions. In: TVA Fertilizer
Conference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-62. August 1973. p. 39-46.
28Liquid Fertilizer Manual. Peoria, Illinois. National
Fertilizer Solutions Association. 1967. 270 p.
29Achorn, F. P., and J. S. Lewis, Jr. Alternative Sources of
Materials for the Fluid Fertilizer Industry. Fertilizer
Solutions Magazine. 1^(4):8-13, July-August 1974.
56
-------
Figure 16. Geographical distribution of liquid mix fertilizer plants in 1972
-------
solution is called a "base" solution and serves much the
same purpose as does diammonium phosphate or triple super-
phosphate in bulk blending of granular fertilizers. Pro-
duction of the ammonium phosphate base solution, whether or
not other raw materials are added at that time, is called
"hot mixing" because the reaction between ammonia and
phosphoric acid during formulation is exothermic. When the
ammonium phosphate solution is shipped as a base solution,
the final mixing process is called "cold mixing."
Figure 17 is a generalized process flow diagram for the
production of liquid mixed fertilizers. In addition, a
diagram of the various methods used for producing liquid
mixed fertilizers is shown in Figure 18.
Liquid mix plants produce two types of fertilizers: clear
liquids (approximately 75%) and suspensions or slurry mix-
tures (approximately 25%). Clear liquid fertilizers contain
less than 0.5% solids by weight and have low salting-out
temperatures. They are easy to store, but usually have a
lower nutrient content than do granular mixtures.
The terms "suspension" and "slurry" fertilizer are often
used interchangeably to designate all fluid fertilizers that
contain solids. Suspension fertilizers are fluid mixtures
of solid and liquid materials in which the solids do not
settle rapidly and can be redispersed readily with agitation
to give a uniform mixture.28 Attapulgite and bentonite
types of clay are added as suspending agents. The suspension
is fluid enough to be pumped and applied to the soil in
application equipment commonly available for clear mixed
liquid fertilizers.
Slurry fertilizers are fluid mixtures of solid and liquid
materials in which the solids settle rapidly in the absence
58
-------
EMISSIONS
t
RAW
MATERIAL
STORAGE
REACTOR-
MIXER
PRODUCT
HEAT
EXCHANGER
COOLING
H20
COOLING
H20
OUT
Figure 17. Generalized flow diagram of the production
of liquid mixed fertilizers
LIQUID MIXED
FERTILIZERS
2,768 PLANTS
4.67 xlO6 METRIC TONS / YR.
HOT MIX PLANTS
830 PLANTS
1.87 xlO6 METRIC TONS / YR.
COLD MIX PLANTS
1,938 PLANTS
2.80x 106 METRIC TONS/YR.
Figure 18. Types of liquid mixed fertilizer plants3'3
30
Private communications. D. K. Murry. National Fertilizer
Solutions Association, Peoria, Illinois.
59
-------
of agitation to form a firm layer which is difficult to
resuspend. Continuous agitation is required to ensure a
uniform mixture that can be pumped and applied to the soil.
Commonly available application equipment usually needs
modification to handle this type of product successfully
because of its higher viscosity.
2. Hot Mix Plants
Hot mix manufacture involves neutralization of wet-process
phosphoric acid to give 8-24-0 ammonium phosphate solution,
or of superphosphoric acid to give 10-34-0 or 11-37-0
ammonium polyphosphate solutions, followed by addition of
nutrients such as urea-ammonium nitrate, ammonium nitrate,
and potash.28 Water is added with these materials to con-
trol the reaction, pH, and specific gravity of the solution.
Potash not only supplies the potassium nutrient but also
lowers the heat of reaction because the reactions with
potash are endothermic. In the ammoniation reaction it is
important to minimize contact between the superphosphoric
acid and water, to avoid rapid hydrolysis of the polyphos-
phates. Therefore, the acid, ammonia, and water are added
simultaneously and the points of acid and water injection
are located at opposite ends of the reactor (Figure 19).
Under these conditions, the acid is neutralized before it
has time to hydrolyze.
The temperature in the reactor depends on the strength and
concentration of phosphoric acid used, the amount of ammonia
added, whether potash is added, and the ambient temperature
of the raw materials. The reaction with potash is endo-
thermic and acts to cool the solution. On the average, the
temperatures in the hot mix reactor range from 27°C to 77°C.
External heat exchangers are used to control the reactor
temperatures and cool the product when necessary.
60
-------
PROCESS WATER
COOLING
WATER (IN)
COOLING WATER
(OUT)
Figure 19.
Reactor assembly for the production of
liquid fertilizer
61
-------
Hot mix plants produce both types of liquid mixed fertilizers:
clear liquids and suspensions. Clear liquids are produced by
adding water, phosphoric acid, ammonia, urea-ammonium nitrate,
and potash to the reactor-mix tank in that order. To produce
suspension mixtures, the clays are added to the tank last
(Figure 20).
There are two types of hot mix plants, specified according
to reactor type: (1) tank reactor, and (2) pipe reactor.
The majority (88%) of the hot mix plants use the tank reactor
design.31 The production of clear liquid mixed fertilizers
by the hot mix tank reactor can be done either on a continu-
ous basis or by batch operations. Figure 21 illustrates one
design of a continuous process hot mix plant for producing
clear liquid fertilizer. The batch-type plant process is
used in approximately 90% of the hot mix plants and is
capable of producing both clear liquids and suspension ferti-
lizers (Figure 22). For suspension mixtures, the attapulgite
clay is added along with the potash.
In early 1970, the TVA helped to develop a pipe reactor
hot mix fertilizer plant that can produce a high analysis
polyphosphate fertilizer. Pipe reactor plants differ from
tank reactor plants in reactor design and the location where
the water is added. Instead of adding all the fertilizer
ingredients to a tank, as in the tank reactor design, the
phosphoric acid and ammonia are combined in a water-jacketed
pipe prior to being mixed with the remaining ingredients.32
3 feline, R. S. Use of a Pipe Reactor in Production of
Liquid Fertilizer of High Polyphosphate Content. Summary
Report. National Fertilizer Development Center, TVA.
Muscle Shoals, Alabama. November 1974. p. 9-11.
32Achorn, F. P., and H. L. Kimbrough. Latest Developments
in Commercial Use of the Pipe Reactor Porcess. Fertilizer
Solutions Magazine. 17_(4) , July-August 1974.
62
-------
U>
EMISSIONS
PHOSPHOR 1C AC I D-i
WATER—»
OTHER —*
(e.g., UREA,
AMMONIUM
NITRATE)
f
AMMONIA
REACTOR
EMISSIONS
i
*- WATER
EVAPORATIVE
COOLER
WASH TANK
EMISSIONS
L
BAG FILTER
CLAY FROM
RAILROAD CARS
CLAY SILO
CLAY
MIX TANK
SUSPENSION PRODUCT
11-39-0
Figure 20. TVA liquid fertilizer suspension mix plant (11-39-0)
-------
o\
EMISSIONS
11
NH3 1652kg/hr
SUPERPHOSPHORIC AC ID 6,426 kg/h r
H20 5,529 kg/h r
COOLING H20
IN [
HEAT
EXCHANGER
(186 m2)
COOLING
OUT
AMMONIA
DISTRIBUTOR
82°C
TURBINE
AGITATOR
SURGE TANK
COOLING COOLING
H20 H20
OUT IN
EMISSIONS
38°C
D
UAN 32-0-0 10,206 kg/h r
— KCI 1,462 kg/h r
- H20 26,557 kg/h r
MIX ING TANK
PRODUCT
8-8-8
57,833 kg/h r
Figure 21. Hot mix plant for the continuous production of clear liquid
fertilizers (57.8 metric tons/hr of 8-8-8) 28
-------
Ul
WET PROCESS
SUPER-
PHOSPHORIC
ACID
72% P203)
UREA-A/N
SOLUTION
(32-0-0)
EMISSIONS
il
NH3
• KCI
•WATER
£
AGITATOR
a
MIXING
TANK
COOLING
WATER IN
HEAT
EXCHANGER
COOLING
WATER OUT
PRODUCT
8-8-8
Figure 22. Hot mix plant for the batch production of clear liquid fertilizers28
-------
Figure 23 illustrates the pipe reactor plant design equipped
with a separate mix tank. The solution and the hot water
from the pipe reactor jacket are added to a mix tank. Other
ingredients such as water, urea-ammonium nitrate and potash
are then added to the mix tank. There are approximately
100 pipe reactor plants of which about 25 use the separate
mix tank design.
Approximately 75 pipe reactor plants combine the mix tank,
cooler, and scrubber into one unit.33 This type of pipe
reactor plant is referred to as the tower design (Figure 24).
Hot solution is injected below the fluid level in the solu-
tion well. Cooling is accomplished by recirculating liquid
from the hot well to the top of the packed bed section
where it is sprayed down through the packing material. Secon-
dary cooling air enters through a gap in the upper walls.
Adjustable plates in this opening control the volume and
velocity of air passing through the packed bed. A demister
is installed above the cooler-scrubber section.34"36
33Killough, B. Liquid Mixing Seminar Is Success. Fertilizer
Solutions Magazine. 18^(5), September-October 1974.
34Achorn, F. P., H. L. Balay, and H. L. Kimbrough. Commer-
cial Uses of the Pipe Reactor Process for Production of
High-Polyphosphate Liquids. Fertilizer Solutions Magazine.
r?(2), March-April 1973.
35Meline, R. S., R. G. Lee, and W. C. Scott. Use of a Pipe
Reactor in Production of Liquid Fertilizers with Very High
Polyphosphate Content. Fertilizer Solutions Magazine.
16^(2), March-April 1972.
36Achorn, F. P., and J. I. Bucy. High-Analysis 12-44-0
Produced by Kugler Oil. Fertilizer Solutions Magazine.
16(5), September-October 1972.
66
-------
cr>
-j
PARTIALLY COOLED 10-34-0 TO COi
AMMONIA
/ '"
WATFB-q. "—•""])
1
)LERS
S.S.DEMISTER
PAD
Figure 23. Plant using pipe reactor process, with wet scrubber separate
mix tank and pipe-type coolers32
-------
00
R£ClRCUlJ>'IlON POMP AMMONIA TO
ftECtflCULATING
LIQUID
Figure 24. Plant using pipe reactor process with tower design32
-------
3. Cold Mix Plants
A cold mix plant is one in which ammoniated phosphoric acid,
such as grades 8-24-0, 10-34-0, or 11-37-0, is blended with
other raw materials, such as urea-ammonium nitrate, potash,
clay and water, at ambient temperatures less than 38°C. These
plants operate on a batch-type basis. A cold-mixed clear
liquid fertilizer station frequently has three tanks for
storage of 10-34-0, 4-10-10, and urea-ammonium nitrate
(32-0-0).37 These solutions are pumped from plastic lined,
mild steel tanks through a volumetric meter. Mixing is
accomplished as the liquids are pumped into a mixing tank
(Figure 25). The mixing tank is open at the top and has a
rotating vane mixer inside for agitation. All of the mixing
equipment is located inside an enclosed building.38
4. Raw Materials
The conventional materials used by fluid fertilizer manu-
facturers are urea-ammonium nitrate solutions (32-0-0, 30-0-0,
and 28-0-0), 10-34-0 or 11-37-0 solutions, superphosphoric
\
acid, potash, and ammonia. All of these materials, except
potash, are currently in very short supply. Other phosphatic
and nitrogeneous materials that are in short supply, but more
readily available, include wet-process orthophosphoric acid,
diammonium phosphate, monoammonium phosphate, prilled urea,
prilled ammonium nitrate, and ammonium sulfate. Additional
materials used to produce suspended liquid mixed fertilizers
37Achorn, F. P., and H. L. Balay. Fluid Fertilizer Mixtures
1972. In: Phosphorus and Agriculture. International
Superphosphate and Compound Manufacturers' Assoc., Ltd.,
London. Publication No. 60. December 1972. p. 27-36.
38T:.nsman, W. S. Mixing Techniques - Part 2 - Cold Mix and
Satellites. Fertilizer Solutions Magazine. 17(3), May-
June 1973.
69
-------
AMMONIUM
NITRATE
32-0-0
STORAGE TANKS
CONTROL BOARD
AMMONIUM
PHOSPHATE
11-34-0
Figure 25. Diagram of a liquid cold mix plant
-------
include 12-40-0 and attapulgite-type clay. Table 15 lists
the raw materials consumed by liquid mixing plants.
Table 15.
RAW MATERIALS CONSUMED BY LIQUID
MIX FERTILIZER PLANTS
Material
Ammonia, anhydrous
Ammonium nitrate (33.5-0-0)
Ammonium sulfate (21-0-0)
Urea, prilled (45-0-0)
Urea-ammonium nitrate (28-0-0,
30-0-0, 32-0-0)
Phosphoric acid
Monoammonium phosphate (11-48-0,
13-52-0, 11-55-0, 16-20-0)
Ammonium polyphosphate (10-34-0,
11-37-0)
Diammonium phosphate (16-48-0,
18-46-0)
Potash
Attapulgite clay
Used at
Hot mix
plants
X
X
X
X
X
X
X
X
X
X
X
Cold mix
plants
X
X
X
X
X
X
X
X
X
Minor nutrients such as calcium, magnesium, sulfur, iron,
and zinc are added to the mixed fertilizers. The general
insolubility of metal cations in orthophosphate solutions
makes it difficult to supply these additional nutrients to
liquid mixed fertilizers. In general, the amount of metal
cations sequestered is proportional to the amount of poly-
phosphate present.39 The metal cations are more insoluble
39Fo.rbes, M. R. Mixing Techniques of Micronutrient with
Liquid and Suspensions. Fertilizer Solutions Magazine,
r? (5) , September-October 1973.
71
-------
in orthophosphates than in polyphosphates. The types of
micronutrients applicable to liquid mixed fertilizers are
shown in Tables 8 and 9.
The largest portion (75%) of the herbicides added to mixed
fertilizers are added to liquid fertilizer mixtures. The
estimated maximum quantities of herbicides added to these
fertilizers are shown in Table 16. Estimates are based on
75% of the values shown in Table 10.
5. Emission Sources
a. Hot Mix Plants - There are two sources of emissions at
hot mix liquid fertilizer plants: (1) hot mix reactor, and
(2) raw materials handling. Emissions from the hot mix
reactor are: (1) ammonia, (2) fluorine compounds, (3) phos-
phorus compounds, and (4) particulate matter. The chemical
natures of these emissions are the same as those described
for emissions from ammoniation-granulation plants. Particulate
emissions from raw materials handling consist of potash and
clays.
b. Cold Mix Plants - The only source of emissions from cold
mix plants is wind erosion from the potash storage pile when
it is located outside of the building (<20% of the plants).
In addition, ammonia may be volatilized from spills resulting
from the filling of the ammonium phosphate or ammonium nitrate
storage tanks.
72
-------
Table 16. ESTIMATED QUANTITIES OF SELECTED HERBICIDES
(ACTIVE INGREDIENTS) USED BY LIQUID MIX PLANTS, 1971
Type of herbicide
Quantity used,
metric tons/yr
Inorganic herbicides
Organic herbicides:
Arsenicals
Phenoxys:
2,4-D
2,4,5-T
MCPA
Other phenoxy
Total
Phenyl urea:
Diuron
Linuron
Fluometuron
Other phenyl urea
Total
Amides:
Propachlor
Propanil
Alanap
Alachlor
Other amides
Total
Carbamates:
EPTC
Pebulate
Vernolate
Butylate
Other carbamates
Total
Dinitro group
Triazines:
Atrazine
Propazine
Simazine
Other triazines
Total
Benzoics:
Amiben
Dicamba
Other benzoics
Total
Other organics:
Trifluralin
Nitralin
Dalapon
Norea
Fluorodifen
Others
Total
Total organic herbicides
(excluding petroleum)
Total herbicides (excluding
petroleum)
Petroleum
Total herbicides
150
700
2,900
120
300
5JL
3,400
1,620
640
5,100
280
150
130
5,600
840
40
10
900
19.800
19,960
12.630
32,590
73
-------
SECTION IV
EMISSIONS
The production of mixed fertilizers gives rise to several
air emission species, namely:
• Gaseous ammonia and chlorine
• Aerosols of sulfates, phosphates,
fluorides, chlorides, and ammonium
chloride
• Particulates
• Pesticides
Of this list, only particulate emissions are classified as
a criteria pollutant by the EPA.
The quantities and species of emissions generated depend on
the type of mixing plant and the nature of the source of
emissions within the plant. All of the above species, except
sulfates, are emitted by liquid mix plants and all of them,
except the pesticides, are emitted at ammoniation-granulation
plants. Emissions from bulk blending plants consist only of
particulates and pesticides. The emission factors (the
quantity of species emitted per unit weight of fertilizer
product) and characteristics of these emission species are
evaluated as functions of operating techniques and emission
sources in the following sections.
75
-------
A. AMMONIATION-GRANULATION PLANTS
1. Selected Emissions
Five plant operations are sources of emissions at ammoniation-
granulation plants. They are described in detail in Section
III. The sources and the emission species associated with
each are as follows:
• Materials storage and handling: particulates
(solid raw materials and product)
• Ammoniator-granulator: ammonia, chloride com-
pounds, fluoride compounds, phosphate compounds,
sulfate compounds, and particulates
• Dryer and cooler: ammonia, chloride compounds,
fluoride compounds, phosphate compounds, and
particulates
• Screen and oversize mill: particulates
• Bagging and loading: particulates
Particulate emissions from materials storage and handling,
screen and oversize mill, and bagging and loading operations
are composed of raw material and finished product particles.
Ammonia related emissions from the ammoniator-granulator and
the dryer and cooler consist of NHa vapor and aerosols of
NH^Cl, (NH4) 2HPOif, and (NH^)2SOlt. The NH3 vapor emissions
are a result of incomplete ammoniation reactions in the
ammoniatior-granulator. The aerosols are produced when
ammonia reacts with the chloride, phosphates, and sulfates
which are produced at the elevated temperatures (82°C) from
the potash, urea, and phosphates.
Chloride related emissions, due to the addition of potash
(KCl), include chlorine vapor and inorganic chloride salts
such as NHitCl and KCl. Fluoride emissions are a result of
trace quantities (1% to 2%) of inorganic fluoride salts in
76
-------
the raw phosphoric acid and normal and triple superphosphoric
acid. Emissions of fluorine are in the form of SiF4 , HF, and
CaF2.20
Incomplete ammoniation reactions generate free phosphate
radicals which combine with elements such as calcium, mag-
nesium, and potassium to produce phosphate aerosol emissions.
These aerosols consist of Ca3(PO4)2, (NHit)2PO4/ E3PO^r and
K2HPO3.21 All sulfur emissions are in the form of inorganic
sulfate salts such as (NHtt)2SO4f CaSO4 and K2SOlf, and E2SO^.
However, due to the completeness of the ammoniation reaction
with H2SOt|/9'18 these emissions are low (<1% of total) and
will therefore be included with particulate emissions.
Ammonium chloride aerosols are formed in the ammoniator-
granulator when sulfuric acid reacts with potassium chloride
(potash) to form hydrogen chloride which, in turn, reacts
with gaseous ammonia. Emissions of ammonium chloride are of
particular interest at these mixing plants because their
small particle size (0.1 ym to 5 ym) dictates the use of
expensive, high efficiency (>99%) control equipment. In
addition, these aerosols produce a very visible, dense,
white plume (>70% opacity) which may exceed local state
opacity regulations.19
To calculate emission factors, source test data from
ammoniation-granulation plants were collected from published
literature and sampling data on file at EPA. The raw data
which were compiled and used to establish emission factors
are given in Appendix B. All of the emission factors in
Table B-l, Appendix B, are normalized to uncontrolled emis-
sions because the type and collection efficiency of the
control equipment used varied from plant to plant. The
collection efficiency of the wet scrubbers used at these
77
-------
plants ranges from 85% to 99.5%. When controlled emission
factors are used later in this section, an average control
efficiency of 85% will be used since an actual distribution
of scrubber collection efficiencies is not available.
Emission factors for the emission species at ammoniation-
granulation plants as a function of emission source categories
are shown in Table 17. The emission factors are calculated
by averaging the appropriate values in Table B-l, Appendix B.
The accuracy values were established by applying a "student t"
test to the input data.
The "t" test deals with the estimation of a true value from
a sample and the establishment of confidence ranges within
which the true value can be said to fall.40 The "t" test is
applied to the input data because the sample sizes are fewer
than 30 in number and thus may not be normally distributed.
The calculated value of "t" is defined as the difference
between the mean of a sample, X, and the true mean of the
population, y, from which the sample was drawn, divided by
the estimated standard deviation of the mean, s(x):
s(X)
where s (X) = ——-
/E
s(X) = the estimated standard deviation of
the sample
n = number of degrees of freedom
40Volk, W. Applied Statistics for Engineers, 2nd Edition,
New York, McGraw-Hill Book Co., 1969. 110 p.
78
-------
Table 17. UNCONTROLLED EMISSION FACTORS FOR AMMONIATION-GRANULATION FERTILIZER PLANTS
Emission source category
Materials storage and
handling
Airanoniator-granulator
Dryer and cooler
Screen and oversize mill
Bagging and loading
Total plant
Emission factor,
g/kg
Ammonia
0
0.503 ± 104%
0.316 ± 44%
0
0
0.819 ± 66%
Total
chlorine
0
0.030 ± 186%
0.014 ± 175%
0
0
0.044 ± 175%
Total
fluorine
0
0.0013 ± 57%
0.0083 ± 70%
0
0
0.0096 ± 61%
Total
phosphorus
0
0.0011 ± 87%
0.0316 ± 133%
0
0
0.0327 ± 133%
Particulate
0.5 ± 300%a
0.175 ± 356%b
0.23 ± 48%
0.25 ± 300%3
0.25 ± 300%3
1.40 ± 300%
These values are a result of engineering estimates of similar processes because no source
test data are available and the values may vary by a factor of three.
large error is due to only two data points which statistically results in a large spread
for 95% confidence range. The standard deviation in the two data points is ±40%.
-------
The "t" function gives the distribution of deviations of X
from y in terms of relative frequencies or probabilities.
Though not normal, the "t" distribution does approach a
normal distribution as n increases to infinity.
By transposing Equation 3, the true mean can be expressed
in terms of the measured mean:
y = X ± ts(X) (4)
Verbally, the true mean can be said, with the tabulated
probability of error, to be within the range of the calcu-
lated mean included in the limits of plus or minus t times
the estimated standard deviation of the mean. The term
ts(X) is considered as an estimation of the precision of the
measurement of X.
The precision values in Table 17 were calculated for a 95%
confidence limit, meaning that there is a 95% chance that
the true mean, y, will be in the range of X ± ts(X). The
statistical data used to establish the precision values
are shown in Table B-2, Appendix B.
The procedure below was used to calculate the precision
value for the sum of two numbers. It is based on the fact
that the variance of the sum of two events is equal to the
sum of the variances of each event:
(A ± a) + (B ± b) = (C ± c) (5)
where C = A + B
c = Va2 + b2
80
-------
and a, b, and c are expressed as a part of A, B, and C,
respectively, and not as a percentage. This procedure was
used to calculate the precision values for ammonia and total
fluorine emissions for a total plant emission factor.
There are no source test data for particulate emissions from
materials storage and handling, screen and oversize mill, and
bagging and loading operations. Therefore, the particulate
emission factors assigned to these source categories were
based on engineering estimates and EPA emission factors for
similar sources. The U.S. EPA and several state EPA's are
using an uncontrolled emission factor of 0.5 g/kg of ferti-
lizer for emissions from materials storage and handling
operations at fertilizer plants. tfl~1*6 These emission factors
may vary by as much as a factor of three, depending on the
individual plants.
The stack data for an average ammoniation-granulation plant
are shown in Table 18. The stack height for the total
plant is for a separate stack from the process operations.
This final stack is downstream from the wet scrubber.
^lPrivate communications. Jim Price. Texas Air Control
Board, Austin.
42Private communications. Ray Beckett. Illinois EPA,
Springfield.
43Private communication. Allen Leevin. Ohio EPA, Dayton.
September 12, 1974.
44Private communications. Robert lacampo. Florida EPA,
Tallahassee.
l+5Private communication. John Pruessner. Indiana Air Pollu-
tion Control Board, Indianapolis. September 19, 1974.
46Compilation of Air Pollutant Emission Factors. U.S.
Environmental Protection Agency. Washington. Publication
No. AP-42. February 1972. p. 6.10.
81
-------
Table 18. STACK DATA FOR AMMONIATION-GRANULATION PLANTS
Emission source
category
Materials handling
and storage
Ammoniator-granulator
Dryer and cooler
Screen and oversize
mill
Bagging and loading
Total plant
Stack data
Height,
m
No stack
17.7
16.8
No stack
No stack
24.1
Diameter,
m
N.A.9
0.6
0.9
N.A.
N.A.
1.1
Temp. ,
°C
N.A.
93
65
N.A.
N.A.
62
Flow rate,
m3/min
N.A.
1,586
368
N.A.
N.A.
481
N.A. = not applicable.
One problem at these plants that is not reflected in Table 17
is the emission of ammonium chloride (NH^Cl) aerosols from
the ammoniator-granulator . These small (0.1 ym to 5.0 ym)
particles cannot be removed by low efficiency (<90%) wet
scrubbers, and occasionally produce a dense (>70% opacity)
white plume. The plumes from some plants exceed state opacity
regulations.19 No source test data exist for NH4C1 emissions,
but the emission factor for chlorine (0.044 g/kg ± 175% of
product) , assuming all chlorine is converted to NHitCl, can be
used as an effective upper limit.
2.
Emission Characteristics
a. Emission Effects - Human - In order to evaluate the
health effects of certain chemicals the American Conference
of Governmental Industrial Hygienists (ACGIH) has adopted a
qualitative toxicity hazard scale which describes the probable
human response to exposure to the chemical substance. These
potential hazard values for the air emission species emitted
from ammoniation-granulation plants are shown in Table 19.
82
-------
Table 19. HUMAN HAZAKD POTENTIAL DUE TO EXPOSURE TO AIR
EMISSIONS FROM AMMONIATION-GRANULATION PLANTS
Emission species
NH3 vapor
NHi^ salts, inorganic
Cl2 vapor
Chloride salts,
inorganic
NH4C1
Ca3(POit)2
(NH4)2HP04
^PO^
Phosphate salts,
inorganic
F2
HF
Fluoride compounds,
inorganic
Particulates
ACGIH toxicity rating47
Acute
Moderate
Slight
Very toxic
Slight
Slight
Slight
Slight
Moderate
Very low
Very to ex-
tremely toxic
Very toxic
Very toxic
Slight
Chronic
Slight
Slight
Unknown
Slight
Slight
Slight
Unknown
Moderate
Very low
Very toxic
Moderate
Very toxic
Unknown
TLV®9'48
mg/m^
18
(10)
3
(10)
10
(10)
(10)
1
(100)
0.2
2
2.5
10
ppm by vol
25
NA
1
NA
NA
NA
NA
NA
NA
0.1
3
1.0
NA
a
Values in parentheses are assigned TLV's based on ACGIH ratings.
b
NA = not applicable.
The acute toxicity rating is a qualitative measure of the
probability that injury may be caused to man as a result of
short duration exposure. Acute, used in a medical sense,
means "of short duration" and refers to a single exposure
of a duration measured in seconds, minutes or hours.47
U7Sax, N. I. Dangerous Properties of Industrial Materials.
3rd Edition. New York, Reinhold Book Corp., 1968. 1251 p.
l+8TLV's® Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment with Intended
Changes for 1975. American Conference of Governmental
Industrial Hygienists. Cincinnati. 1975. 97 p.
83
-------
Chronic exposures refer to prolonged or repeated exposures
of "long duration," measured in terms of days, months, or
years.
An acute toxicity rating of "slight" refers to a material
which on single exposures lasting seconds, minutes, or hours
causes only slight detrimental health effects, essentially
regardless of the quantity or extent of exposure. An acute
toxicity rating of "very toxic" refers to a material which
on single exposures lasting seconds, minutes or hours causes
injury of sufficient severity to threaten life or to cause
permanent physical impairment or disfigurement.
Threshold limit values (TLV's) set by the ACGIH represent
conditions under which it is believed 'that nearly all
workers may be repeatedly exposed day after day, without
adverse effect.1*8 For example, the ACGIH believes that a
person can be exposed to 18 mg/m3 of vaporous ammonia through-
out an 8-hour day without experiencing adverse effects.
In experimental toxicology it is common practice to determine
the quantity of poison per unit of body weight (of an experi-
mental animal) that will have a fatal effect. The values
are expressed as milligrams of poison per kilogram of body
weight. A commonly used concentration figure is the amount
of poison which will kill one-half of a group of experimental
animals. This is known as the LD50 test (lethal dose - 50%)
representing 50% fatalities. When TLV's are not available,
LDso values can be used to estimate the relative toxicity of
a chemical.
The particulate emissions from materials storage and handling,
screen and oversize mill, and bagging and loading operations
consist of raw material and mixed fertilizer particles. The
84
-------
TLV's for the raw materials, secondary, and micronutrients
used by fertilizer mixing plants are given in Appendix C.
A composite TLV of 10 mg/m3 will be used for particulate
emissions in general when no specific chemical analysis is
provided.
b. Particle Size - The particle size analyses of the
granular raw materials used at ammoniation-granulation plants
are shown in Appendix A. Approximately 90% of these materials
range in size between 1 mm and 4 mm in diameter, with
approximately 5% less than 1 mm in diameter. Ammoniation-
granulation plants produce granular fertilizers ranging in
size from 1 mm to 4 mm in diameter.
The particle size distribution analyses for the uncontrolled
emissions from the dryer, cooler, and bagging operations are
shown in Table 20.49 The solids loading for the dryer
ranged from 1.6 to 9.2 g/m3. Approximately 66% of the
Table 20. PARTICLE SIZE DISTRIBUTION OF THE EMISSIONS
FROM THE DRYER, COOLER, AND BAGGING OPERATIONS49
Particle size,
ym
5
10
20
30
40
>40
Percent distribution
less than particle size
Dryer
6.3
12
22
29
34
66
Cooler
6.2
11.1
20.0
24.1
32.0
68.0
Bagging
2
3
5.8
14
31
69
l+9Particulate Pollutant System Study, Vol. Ill - Handbook of
Emission Properties. U.S. Environmental Protection Agency,
Washington. PB 203522. May 1971. p. 313-338.
\
85
-------
emissions by weight from the dryer are greater than 40
in diameter and approximately 68% of the emissions by weight
from the cooler and bagging operations are greater than
40 ym in diameter.
There is no information in the literature on the particle
size distribution of emissions from an ammoniator-granulator .
c. Atmospheric Stability - To fully characterize the emis-
sion species, their chemical stabilities in the atmosphere
must be considered. In the atmosphere, an emission species
may undergo either a photochemically induced reaction with
other chemicals or photochemical dissociation. Ultraviolet
light is usually responsible for supplying the energy needed
to initiate the photochemical reactions.
The primary reaction process for ammonia vapor (NH3) is the
photochemical dissociation of:50
NH3 - NH2 + H (6)
Unfortunately, no data describe how much of the NH3 is
dissociated. The NH2 radical is then free to react with O2
to form NO and H20. Again, the rates of this secondary
reaction have, not yet been determined.
Chlorine emissions consist primarily of stable inorganic
chlorine salts (e.g. , NH^Cl) , but a small portion (<10%)
is emitted as free chlorine. Photochemical reaction studies
have shown that the free chlorine will combine with olefins
50McNesby, J. R., and H. Okabe. Vacuum Ultraviolet Photo-
chemistry. In: Advances in Photochemistry, Vol. 3,
Noyes, W. A., Jr. (ed). New York, John Wiley and Sons
Publishers, 1964. p. 157-240.
86
-------
such as ethylene to form chloroethylenes.5l While this
vinyl chloride has a very low TLV (<0.001 g/m3), it actually
presents no problem around the mixing plants because: (1)
the reaction rate between chlorine and olefins is believed
to be low,51 and (2) actually, less than 0.0006 gram of free
chlorine per kilogram of fertilizer is emitted to the atmos-
phere due to existing control equipment.
Particulates in the atmosphere serve as activation sites and
catalysts for photochemical reactions. The metal atoms in
these particles serve as energy transfer agents by first
absorbing high energy ultraviolet radiation and then trans-
ferring the energy to other chemical compounds - supplying
the required energy for decomposition and the formation of
other chemical compounds.
Turbulence in the atmosphere can cause the large (>100 ym)
particles to break apart, producing small particles which
can serve as condensation nuclei. Depending on the ambient
temperature and relative humidity, these small particles can
cause haze, fog, or rain.
Very little information exists about the photochemical
nature of phosphate compounds and fluorides. Fluorides,
especially HF, are very reactive and will react, for example,
with olefins in the atmosphere.
51Cvetanovic, R. J. Addition of Atoms to Olefins in the
Gas Phase. In: Advances in Photochemistry, Vol. 1,
Noyes, W. A., Jr. (ed.). New York, John Wiley and Sons
Publishers, 1963. p. 115-182.
87
-------
B. BULK BLENDING PLANTS
1. Selected Emissions
Air emissions from bulk blending plants consist only of
particulate matter composed of raw materials and mixed
fertilizer particles. These particulate emissions may also
include trace quantities (<0.1%) of herbicides.
Emissions from these plants are fugitive in nature, in that
they are not emitted from a stack. The three process oper-
ations responsible for dust emissions are:
• Materials storage and handling
• Loading operations
• Fugitive building emissions
Fugitive dust emissions from materials storage and handling
operations result from unloading hopper-bottom railroad cars
and transporting the granular raw materials to the building
by screw conveyors, belt conveyors, and bucket elevators.
The loading of bulk fertilizer into open trucks constitutes
another source of fugitive dust emissions.
Additional emissions issue from the windows, doors, and
ventilation system of the bulk blending plant as a result of
materials handling, mixing, and bagging operations within
the building.
The particulate emission factors for emissions from the
three sources at bulk blending plants are presented in
Table 21. Since no source test data concerning emissions
are available, an alternate method was used to establish
emission factors. Observations at various blending plants
indicated that the amount of dust emitted during the loading
88
-------
Table 21. UNCONTROLLED PARTICULATE EMISSION FACTORS
FOR BULK BLENDING FERTILIZER PLANTS
Emission source category
Material storage and handling
Loading operations
Fugitive building dust
Total plant
Emission factor,
g/kg
0.1 ± 100%
0.1 ± 100%
0.1 ± 100%
0.3 ± 100%
operations depended on the type of raw materials used.
Therefore, a particle size analysis of the basic raw materials
used at blending plants was conducted. Detailed descriptions
of the plants sampled and analytical procedures used are
presented in Appendix D.
The emission factors in Table 21 are a result of this analysis
and are based on the fraction of the raw material which has
a particle size less than 44 ym. These small particles will
remain suspended in the air long enough to be transported
away from the blending plants' property lines. The larger
particles which might be injected into the air due to the
loading operations will settle to the ground within the plants
property lines.
The emission factors in Table 21 are reported as uncontrolled
because less than 2% of the bulk blending plants use any
form of pollution control equipment. Less than 5% of the
plants use dust depressants (e.g., oil or 10-34-0) to reduce
dust concentrations in the plant.
It is not possible to determine exactly how much secondary
nutrients and micronutrients are added to bulk blended
mixed, fertilizers from the existing raw materials reporting
\
systems.
89
-------
Table 7 shows only the amount of these materials consumed
as fertilizers in the U.S. in 1972. In order to determine
a maximum emission factor for minor nutrient materials, the
following estimation procedure is used for bulk blending
plants:
(Total agricultural\
micronutrient I x 52% x 70% x 0.03%
_ consumption / /Qx
^ \ -7 /
g/ g (2,820) x (1,152)
where the total agricultural micronutrient consumption is
obtained from Table 7 and
52% = portion added to mixed fertilizers, based on
the ratio of mixed to total fertilizer
consumption, 1972
70% = portion added to bulk blended fertilizers,
based on estimates by TVA experts22
0.03% = portion lost to atmosphere, based on emission
factor of 0.3 g/kg
2,820 = number of bulk blend plants which add these
» materials, based on estimates by TVA experts
(50% of 5,640 plants)22
1,152 = average plant annual fertilizer production
rate, metric tons/yr
The results in Table 22 indicate that emission factors for
all of the secondary nutrient and micronutrient materials,
except gypsum, are less than 0.001% of the total plant
emission factor. Therefore, based on the low emission
factors and high TLV's (see Appendix C), these materials
will be grouped with the particulate emissions in general
and not carried as separate emission species.
In terms of emission factors for herbicides, a similar
estimation procedure is used because consumption values for
herbicides at bulk blending plants do not exist. The
90
-------
Table 22. ESTIMATED MAXIMUM UNCONTROLLED EMISSION FACTORS FOR SECONDARY
AND MICRONUTRIENT MATERIALS USED AT BULK BLENDING PLANTS
Material
Aluminum compounds
Boron compounds
Calcium sulfate
(gypsum)
Copper compounds
Iron compounds
Magnesium compounds
Manganese compounds
Sulfur
Zinc compounds
Other
Total agricultural
micronutrient consumption,
metric tons
140
4,500
190,000
500
9,300
1,300
3,000
25,000
21,000
41,000
Estimated
emission factor,
yg/kg
0.005
0.2
6.0
0.02
0.3
0.04
0.1
0.8
0.7
1.0
Percent
of total
emission factor
<0.001
<0.001
0.002
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
Not including the 887,585 Mg of gypsum applied directly
to the soil in California.
-------
following estimation procedure is used to calculate the
maximum emission factor.
Emission factor, _ (Herbicide consumption) x 0.03%
g/kg (1,692) x (1,152)
where the herbicide consumption is obtained from Table 14
and
0.03% = portion lost to the atmosphere, based on
emission factor of 0.3 g/kg
1,692 = number of bulk blending plants adding
herbicides, based on estimates by TVA
experts3
1,152 = average plant annual fertilizer production
rate, metric tons/yr
The results of the analysis are shown in Table 23. The
maximum emission factors range from 0.001 to 0.3 yg/kg of
fertilizer produced and all species are less than 0.001% of
the total particulate emissions. Herbicide emissions will
be grouped with all particulate emissions because: (1) the
emission factor for each herbicide never exceeds 0.001% of
the total plant emission factor; and (2) the value of x" /TLV
UlclX
never exceeds 0.001.
2. Emission Characteristics
a. Emission Effects - Human - A composite TLV of 0.01 g/m3
will be used for particulate emissions from bulk blending
plants when considering the potential human health effects
from exposure to these emissions. Since the chemical compo-
sition of these particulate emissions consists of raw
materials, secondary nutrients, and micronutrient particles,
the TLV's for these compounds are presented in Appendix C.
The lowest reported TLV is 0.001 g/m3.
92
-------
Table 23. ESTIMATED MAXIMUM EMISSION FACTORS FOR
SELECTED HERBICIDES (ACTIVE INGREDIENTS) USED
AT BULK BLENDING PLANTS
Type of herbicide
Emission factor,
ug/kg
Inorganic herbicides
Organic herbicides:
Arsenicals
Phenoxys:
2,4-D
2,4,5-T
MCPA
Other phenoxy
Total
Phenyl urea:
Diuron
Linuron
Fluometuron
Other phenyl urea
Total
Amides:
Propachlor
Propanil
Alnap
Alachlor
Other amides
Total
Carbamates:
EPTA
Pebulate
Vernolate
Butylate
Other carbamates
Total
Dinitro group
Triazines:
Atrazine
Propazine
Simazine
Other triazines
Total
Benzoics:
Amiben
Dicamba
Other benzoics
Total
Other organics:
Trifluralin
Nitralin
Dalapon
Norea
Fluorodifen
Others
Total
0.008
0.04
0.006
0.008
0.02
0.002
0.03
0.02
0.004
0.02
0.03
0.02
0.08
0.03
0.3
0.01
0.005
0.005
0.3
0.04
0.002
0.001
0.06
93
-------
The TLV's for the herbicides used at bulk blending plants
are shown in Appendix E. The lowest TLV is 0.0005 g/m3.
Since only three of these herbicides have established TLV's,
the LD50 values are presented as a relative measure of
hazard.
b. Atmospheric Stability - Since their chemical composition
(inorganic salts) makes these particulate emissions stable
in the atmosphere, they will not undergo photochemical
reactions.
C. LIQUID MIX PLANTS
1. Selected Emissions
Only hot mix-type liquid mix plants have air emissions.
Cold mix-type plants have none because they simply mix,
without chemical reaction, two or more fluids at ambient
temperature and pressure.38
The two process operations producing emissions are:
• The hot mix reactor
• Raw materials handling
Detailed descriptions of these two emission sources are
given in Section III.E.2.
Emission species from hot mix plants are similar to those
from ammoniation-granulation plants, namely:
• Ammonia vapor and ammonium salts
• Fluorine compounds
• Phosphorus compounds
• Particulates
• Herbicides
94
-------
Chlorine emissions are eliminated because phosphoric acid is
used instead of sulfuric acid, and the potash is added after
the hot mix reactor. All of the emission species, except
herbicides, are emitted from the hot mix reactor. Particu-
lates and herbicides are emitted from the raw materials
handling operations.
The emission factors for the emission species from liquid
mix plants are given in Table 24. For consistency, these
values are reported as uncontrolled emissions. The raw data
used to compile these factors are presented in Appendix F.
Emission factors in Table 24 were averaged from source Test
1 and 2 (Appendix F) because experts at TVA indicated that
the majority (>90%) of the hot mix-type plants use those
operating conditions.2 2
The accuracy of the emission factors reported in Table 24 is
±100% when applied to hot mix plants which do not use a
forced draft blower (>90% of plants) and ±300% when applied
to plants which do use the blower (<10% of plants). These
accuracy values are based on the following criteria:
The accuracy of the source test data in Appendix F
is approximately ±30%, based on analysis of the
sampling train and communications with TVA experts
who conducted the tests.9
The range in the emission factors in the source
test data was 10% to 100% from the average
(Appendix F).
The 300% accuracy value was established using Tests
3 and 4 (Appendix F) and comparing the values to those
of Tests 1 and 2.
There are no emissions of secondary nutrients and micro-
nutrients at liquid mix plants because they are added to the
mixture either in a liquid form or a very soluble powdered
form.
95
-------
Table 24. UNCONTROLLED EMISSION FACTORS FOR LIQUID MIX FERTILIZER PLANTS
Emission source
category
Hot mix reactor
Raw materials
handling
Total plant
Emission factor, g/kg
Ammonia
0.073 ± 100%
0
0.073 ± 100%
Total
fluorine
0.001 ± 100%
0
0.001 ± 100%
Total
phosphorus
0.0005 ± 100%
0
0.0005 ± 100%
Particulate
0.008 ± 100%
0.25 ± 200%8
0.258 ± 100%
Stack data
Height,
m
10.7
N.S.b
10.7
Diam. ,
m
0.61
N.S.
0.61
Temp . ,
°C
38
N.S.
38
Flow
rate,
m3/min
28
N.S.
28
10
Based on an engineering estimate; value may vary by a factor of two.
3N.S. = No stack.
-------
The powdered form is added to the fluid mixture by hand
pouring a bag (<22.7 kg) of material into the final mixing
tank.
The estimated maximum emission factors for selected herbicides
at liquid mix plants are shown in Table 25. The following
estimation procedure was used because the existing materials
reporting systems do not include the consumption of herbi-
cides at liquid mix plants, and source test data do not
exist for these emission species:
Emission factor, _ (Consumption value) x 0.025% ,..,.
g/kg (2,214) x (1,690)
where the consumption value is shown in Table 14 and
0.025% = portion lost to atmosphere, based on
emission factor of 0.25 g/kg of herbi-
cide (same as raw materials handling)
2,214 = number of liquid mix plants adding
herbicides
1,690 = average plant annual production rate,
metric tons/yr
2. Emission Characteristics
a. Emission Effects - Human - The TLV's for the various
emission species at liquid mix plants are shown in Table 19.
The TLV's for the raw materials used at these plants are
given in Appendix C, and those for the selected herbicides
appear in Appendix E.
b. Atmospheric Stability - The atmospheric stability of
the emissions from liquid mix plants is identical to that
of emissions from ammoniation-granulation plants (Section
IV.A.2.C).
97
-------
Table 25. ESTIMATED MAXIMUM EMISSION FACTORS FOR
SELECTED HERBICIDES (ACTIVE INGREDIENTS) USED
AT LIQUID MIX PLANTS
Type of herbicide
Emission factor,
g/kg
Inorganic herbicides
Organic herbicides:
Arsenicals
Phenoxys:
2,4-D
2,4,5-T
MCPA
Other phenoxy
Total
Phenyl urea:
Diuron
Linuron
Fluometuron
Other phenyl urea
Total
Amides:
Propachlor
Propanil
Alnap
Alachlor
Other amides
Total
Carbamates:
EPTA
Pebulate
Vernolate
Butylate
Other carbamates
Total
Dinitro group
Triazines:
Atrazine
Propazine
Siraazine
Other triazines
Total
Benzoics:
Amiben
Dicamba
Other benzoics
Total
Other organics:
Trifluralin
Nitralin
Dalapon
Norea
Fluorodifen
Others
Total
0.00001
0.00002
0.00008
0.00001
0.00001
<0.00001
0.00009
0.00001
0.00001
0.00001
<0.00001
0.00002
0.00006
0.00002
0.00001
0.00004
<0.00001
0.00012
0.00001
0.00001
0.00001
0.00002
0.00002
0.00007
0.00002
0.00014
0.00001
0.00001
0.00001
0.00017
0.00003
<0.00001
<0.00001
0.00003
0.00003
0.00001
<0.00001
0.00001
0.00001
0.00001
0.00006
98
-------
D. ENVIRONMENTAL EFFECTS
The potential environmental effects of air emissions from
fertilizer mixing plants can be studied in several ways. One
method is to determine the ground level concentration of
emission species downwind from the plant and compare this value
to the ambient air quality standard for the criteria pollu-
tants or to the TLV for the noncriteria emission species.
The comparison is known as the source severity, S, and is
defined as:
S = (12)
where x = the maximum 24-hour time-weighted average
x ground level concentration for each emission
species
F = primary ambient air quality standard for
criteria pollutants,
8 1
or F = TLV x 24" x Yon"' ^or n°ncriteria emission
species,
and TLV = threshold limit value for each species
correction fac
exposure level
o
• = correction factor to adjust the TLV to a 2 4 -hour
= safety factor
Since ambient air quality standards exist for only five
pollutants (particulates, SO , NO , CO, and oxidants) ,
X X
TLV's represent the only other basis for objective compari-
son for noncriteria emission species.
The 24 -hr time-weighted average of the maximum downwind
ground level concentration of each emission species emitted
Criteria pollutants are those for which air quality stan-
dards have been established.
99
-------
from a typical plant (Table 1), is defined as:52
0. 17
= X — (13)
max max ' ••- '
x = --- (14)
where xmax -
and Q = emission rate, g/s
TT = 3.14
e = 2.72
u = average wind speed, m/s
h = stack height, m
For a 24-hr time-weighted ground level concentration, the
values of time for t0 and tj (Equation 13) are 3 min and
1,440 min respectively. Therefore, Equation 13 reduces to
°*17
max ~ max ,1, 440/ - . max
- _ \ _
x ~ x / - 0.35 x
The equation for x (Equation 14) is derived from the
rcicix
general plume dispersion equation for an elevated source,
ground level (z = 0) concentration, radially (y = 0) down-
wind from the source, and for U.S. average atmospheric
stability conditions.52 A wind speed of 4.5 m/s (10 mph)
is used for u.
Table 26 presents the values of x as a function of
max
emission source for each emission species from a typical
plant of each of the three types. These values are based
52Turner, D. B. Workbook of Atmospheric Dispersion Estimates.
U.S. Department of Health, Education and Welfare. Cincinnati
Public Health Service. Publication No. 999-AP-26. 1969.
62 p.
100
-------
Table 26. MAXIMUM GROUND LEVEL CONCENTRATIONS (x ) OF CONTROLLED EMISSION
IHclX
SPECIES FROM FERTILIZER MIXING PLANTS
Emission source category
Ammoniation-granulation plants
Materials storage and handling
Ammoniator-granulator
Dryer and cooler
Screen and oversize mill
Bagging and loading
Total plant
Bulk blend plants
Materials storage and handling
Loading operations
Fugitive building dust
Total plant
Liquid mix plants
Hot mix reactor
Raw materials handling
Total plant
Average
stack
height,
m
a
6.03
17.7
16.8
16. 8a
6-°b
24.1°
•*
6.0*
6. Of
6.0*
6.03
15. Oa
6.0a
15.0
xmax' "g/m3
Ammonia
0
17.7
12.4
0
0
15.6
0
0
0
0
0.6
0
0.6
Total
chlorine
0
1.1
0.5
0
0
0.8
0
o-
0
0
0
0
0
Total
fluorine
0
<0.1
<0.1
0
0
0.2
0
0
0
0
0.1
0
0.1
Total
phosphorus
0
<0.1
1.2
0
0
0.6
0
0
0
0
<0.1
0
<0.1
P articulate
154
6.2
9
9.8
76.8
26.6
12.6
12.6
12.6
37.9
<0.1
0.2
0.2
This process has no stack; only fugitive emissions are present; a stack height of 6 m was thus used.
Final stack after wet scrubber.
"Based on uncontrolled emission factors.
-------
on the current level of emission control efficiencies at
these plants in order to evaluate the true environmental
impact of the emissions. On the average, ammoniation- granu-
lation and liquid mix plants use medium efficiency (85%) wet
scrubbers to control emissions and recover raw materials.
(A detailed analysis of the existing control equipment is
presented in Section V.) Bulk blend plants, on the other
hand, use no emission control devices and the values of
XT,,.,^ for these plants are based on uncontrolled emission
IRclX
factors. The values of S corresponding to the values of
Xmav for total plant emissions from each typical mixing plant
IllcLX
are given in Table 27.
Table 27. VALUES OF MEAN SOURCE SEVERITY FOR
CONTROLLED EMISSIONS
Pollutant
Ammonia
Total chlorine
Total fluorine
Total phosphorus
Particulate
TLV,
mg/m3
18
3
2.5
100
0.26b
Mean source severity
Ammoniation-
granulation
0.26
0.08
0.02
0.002
0.1
Bulk
blend
0
0
0
0
0.14
Liquid
mix
0.01
0
0.01
<0.01
0.01
Based on uncontrolled emission factor.
Primary ambient air quality 24-hour standard.
The potential environmental impact of the emissions from
mixing plants can also be evaluated by determining the total
mass of each emission species emitted. The annual masses
of emissions from all fertilizer mixing plants in the U.S.
are given in Table 28.
102
-------
Table 28. ANNUAL MASSES OF EMISSIONS FROM FERTILIZER MIXING PLANTS IN THE U.S.
Emission source category
Ammoniation-granulation plants
Materials storage and handling
Ammonia tor-granulator
Dryer and cooler
Screen and oversize mill
Bagging and loading
Total plant
Bulk blending plants
Materials storage and handling
Loading operations
Fugitive building dust
Total plant
Liquid mix plants
Hot mix reactor
Raw materials handling
Total plant
Total mixed fertilizer industry
Mass of emissions, metric tons/yr
Ammonia
0
690 ± 720
430 ± 190
0
0
1,120 ± 740
0
0
0
0
50 ± 50
0
50 ± 50
1,170 ± 740
Total
chlorine
0
40 ± 70
20 ± 30
0
0
60 ± 100
0
0
0
0
0
0
0
60 ± 100
Total
fluorine
0
2 ± 1
11 ± 8
0
0
13 ± 8
0
0
0
0
1 ± 1
0
111
14 ± 8
Total
phosphorus
0
2 ± 2
43 ± 60
0
0
45 ± 60
0
0
0
0
0.4 ± 0.4
0
0.4 ± 0.4
45 ± 60
Particulates
685 ± 2,050
240 ± 850
315 ± 150
340 ± 1,030
340 ± 1,030
1,920 ± 5,760
640 ± 640
640 ± 640
640 ± 640
1,930 ± 1,930
6 ± 6
175 ± 350
180 ± 180
4,030 ± 4,030
o
CO
Based on controlled (85%) emission factors.
Based on uncontrolled emission rates.
CColumns may not total due to rounding.
-------
The total masses of particulate emissions from each of the
three types of mixing plants in the U.S. are shown separately
in Table 29. Controlled (85%) particulate emission factors
were used for ammoniation-granulation and liquid mix plants
because all of these plants on the average use medium effi-
ciency (85%) wet scrubbers. Table 29 compares the masses of
particulate emissions from fertilizer mixing plants with the
total amount of particulate emissions in the U.S. in 1972.53
The results indicate that total particulate emissions from
fertilizer mixing plants do not exceed 0.02% of the total
national particulate emissions.
Table 29. COMPARISON OF FERTILIZER MIXING PLANT GENERATED
PARTICULATE EMISSIONS TO TOTAL NATIONAL PARTICULATE
EMISSION VALUES
Plant type
Total
particulates
emitted,
metric tons/yr
National
particulate
emissions,
metric tons/yr
53
Percent
contribution
by
mixing plants
Ammoniation-
granulation
Bulk blend
Liquid mix
Total
1,920 ± 5,760
1,930 ± 1,930
181 ± 181
4,031 ± 4,031
16,843,754
16,843,754
16,843,754
0.01
0.01
0.001
0.02
A detailed comparison of the mass of particulates emitted by
fertilizer mixing plants to the total mass of particulate
emissions in each state is presented in Appendix G. The
production values for each state are determined by multiplying
53National Emission Report - 1972. U.S. Environmental
Protection Agency. Washington. Publication No. EPA-
450/2-74/012. June 1974. 422 p.
104
-------
the average plant production rate by the number of plants
and summing for the three types of mixing plants. This
procedure is necessary because state production values are
not compiled by the materials flow reporting systems. Only
state fertilizer consumption values are reported. The mass
of particulates emitted by each type of mixing plant in
each state is calculated by the following equation:
/ Mass of \ /ParticulateN /Average annualX /Number of\
Jparticulatej = I emission J x I production ] x I plants in j (15)
I emissions / \ factor / \ rate / ythe state/
The values for the ratio of the mass of particulate emissions
from fertilizer mixing plants to total state particulate
emissions range from 0.001% to 0.2% with an average value of
0.03%.
The population density around a mixing plant is another
factor in determining its potential environmental impact.
A detailed study was made on mixing plant locations, pro-
duction rates, and population distributions in four states
that contain 36% of the mixing plants: Illinois, Iowa,
Missouri, and Ohio. These states were also considered
because they could provide detailed consumption values by
counties. Population densities were calculated from. 1970
census data for each county that contained fertilizer mix-
ing plants. Tonnage reports (amount of fertilizer consumed
in each county) were used instead of production values
because production rates were not reported on a county by
county basis. The results of this comparison are shown in
Table 30. They indicate that 56.6% of the mixing plants
are located in counties with a population density of less
than 19 persons/km2. In addition, 82.1% of the mixing plants
are located in counties of less than 39 persons/km2.
105
-------
Table 30. DISTRIBUTION OF FERTILIZER MIXING PLANTS IN SELECTED STATES*
County
population
density,
persons/km2
<19
19 to 39
39 to 193
193 to 386
386 to 579
>579
Total
Number of
counties
in range
211
77
56
4
5
5
358
Number of
plants in
these
counties
1,546
698
416
18
21
29
2,728
Percent
of
plants
in range
56.6
25.5
15.2
0.7
0.8
1.2
100.0
Tonnage
consumed
in county
2,239
1,189
779
43
26
30
4,306
Percent
tonnage
in
counties
52.0
27.6
18.1
1.0
0.6
0.7
100.0
Selected states were Illinois, Iowa, Missouri, and Ohio because
their county tonnage values are available.
Tonnage expressed in Gg.
-------
It has been reported that the majority of the fertilizer
mixing plants sell their products within an 80 km radius
from the plant.15'28 This fact is supported by the close
correlation shown in Table 30 between the location of the
mixing plants and the consumption of mixed fertilizers.
Using the average population density around a mixing plant,
one can determine an affected population. The affected popu-
lation is defined as the number of persons around a typical
mixing plant exposed to emission concentrations which cause
the ratio of x/F to exceed 0.1 or 1.0. Plume dispersion
calculations (Equation 5.13, Reference 52) determine the two
downwind distances for which the ratio falls below 0.1 (see
Figure 26). Calculations are also made for a ratio of 1.0.
These two distances are used to calculate the annular area
around the plant. The affected population is calculated by
multiplying this area by the average population density around
a mixing plant (39 persons/km2).
1.0 J—
DISTANCE FROM SOURCE
Figure 26. General distribution of mean source severity as
a function of distance from the source, showing the two
' general roots to the plume dispersion equation
107
-------
The affected population values for emissions from the three
representative mixing plants described in Table 1 are given
in Table 31.
Table 31.
AFFECTED POPULATION AROUND REPRESENTATIVE
FERTILIZER MIXING PLANTS
Plant type
Ammoniation-
granulation
Bulk blend
Liquid mix
Emission
species
Ammonia
Chlorine
Fluorine
Phosphorus
Particulate
Particulate
Ammonia
Fluorine
Phosphorus
Particulate
Affected population,
persons
S > 0.1
48
oa
0
0
.6
2
0
0
0
0
S > 1.0
ob
0
0
0
0
0
0
0
0
0
Values of zero mean that the values of
S do not exceed 0.1.
Values of zero indicate that the values
of S do not exceed 1.0.
108
-------
SECTION V
CONTROL TECHNOLOGY
The type of air pollution control equipment used at ferti-
lizer mixing plants varies from plant to plant depending on
plant type, production capacity, and operating conditions.
For example, bulk blending plants that operate on a batch-
type basis for 4 months per year and mix 900 metric tons of
fertilizer use no emissions control equipment. On the other
hand, large (>45 x 103 metric ton/yr) ammoniation-granulation
plants that operate year-round use cyclones and wet scrubbers
to recover product and reduce emissions.
With the rapidly increasing prices of fertilizers, it is
becoming more economical to recover emissions in the manu-
facturing process and recycle them. In general, several
types of pollution control equipment can be used. The
collection efficiencies for various types of this equipment
are shown in Figure 27. The following sections discuss in
detail the measures used by the three types of mixing plants
to reduce emissions by either process modification or pollu-
tion control devices.
A. AMMONIATION-GRANULATION PLANTS
1. Process Modifications
In the ammoniation reaction, ammonia is mixed with sulfuric
or phosphoric acid. When sulfuric acid is used, it reacts
109
-------
99 99
Figure 27. Participate collection efficiencies for various types of control equipment514
5ltTowards Cleaner Air - A Review of Britain's Achievements.
Information for the British Overseas Trade Board. London.
Central Office of
April 1973. 59 p,
-------
with potassium chloride in the granulator to form hydrogen
chloride, which in turn reacts with ammonia to form ammonium
chloride aerosols. The aerosol particles are small (0.1 ym
to 5 ym) and produce a white plume.
One approach toward the elimination of these emissions is to
use superphosphoric acid instead of sulfuric acid. The
results of stack measurements at an ammoniation-granulation
plant in Maryland using these two acids are shown in Table 32
Ammonia emissions from the ammoniator-granulator were re-
duced by 94% when superphosphoric acid was substituted for
sulfuric acid. In addition, chlorine emissions decreased
by 99.9% during the same test. Ammonium chloride emissions
are reduced when the ammonia emissions are decreased, and
the chlorine remains in solution.
Table 32. STACK MEASUREMENTS AT AN
AMMONIATION-GRANULATION PLANT IN MARYLAND55
Source
Ammoniator-
granulator:
NH3
Cl
F
P2Os
Plant stack:
NH3
Cl
F
P205
Emissions,
g/kg of fertilizer
With b
H2S04
3.37
1.78
0.001
0.002
1.87
0.06
0.003
0.06
With
H3P04 (76% P205)
0.195
0.002
<0.0002
0.002
0.54
0.018
0.0018
0.039
Samples taken after the wet scrubber,
Using 62.5 g/kg of fertilizer.
*
'Using 75 g/kg of fertilizer.
55Achorn, F. P., H. L. Balay, E. D. Myers, and R. D. Grisso.
A Pollution Solution for Granulation Plants. Farm Chemicals
134, August 1971.
Ill
-------
While this process modification does reduce emissions, its
use would eliminate a large sink for sulfuric acid produced
by pollution control equipment in other industries. Ammonia-
tion-granulation plants consume 816.5 x 103 metric tons of
sulfuric acid a year,22 approximately 20% of which is obtained
from pollution control equipment.
The particulate collection efficiency of dry cyclones increases
as the gas flow rate increases. However, increasing the ex-
haust gas flow rate also increases the gas flow rate through
the dryer. It has been reported that additional dust is
emitted from the discharge end of the dryer when the gas
velocity exceeds 122 m/min.26 One way to increase the gas
velocity in the cyclone, but not in the dryer, is to install
an open duct in the exhaust line between the cyclone and the
dryer and cooler discharge as shown in Figure 28. The velo-
city of the gas through the dryer and cooler can then be
regulated by means of the damper installed in the line. This
duct system can also be connected to the exhaust system to
collect particulate emissions from the screens, crushing mills,
elevators, and transfer points as shown in Figure 29.
High dust concentration also occurs where chutes from the
screen and cyclones empty onto the recycle belt conveyor.
Engineers at TVA working with fertilizer companies have
eliminated most of this dust by installing a flap cover to
form a dust seal on the cyclone, as shown in Figure 30.26
Other companies have found that a molded rubber seal and
cleated drag conveyor, as are shown in Figure 31, eliminate
this source of emissions.
2. Pollution Control Devices
All ammoniation-granulation plants use some form of air
pollution control device, such as wet scrubber, cyclone,
112
-------
FRESH AIR
IN
TO SCRUBBER
CYCLONE
SEPARATOR
Figure 28. Cyclone gas velocity control26
113
-------
SCREEN
BELT TRANSFER
POINT
CYCLONE
SEPARATOR
•>^ COOLER OR
r DRYER
DUCT
I'f V
Figure 29. Utilization of dryer and cooler exhaust
blower to remove in-plant dust26
114
-------
r
CYCLONE
0.35 m
FLAP COVER
CLEAN-OUT DOORS
CONVEYOR
Figure 30. Dust collector seal26
115
-------
CYCLONE
, j*—,si f—.- . •• •
TF ir r y
DRAG CONVEYOR
Figure 31. Dust-tight cyclone closure, molded rubber seal26
116
-------
baghouse, or a combination of devices. Due to the diversity
of the industry, however, no data are available on the distri-
bution of these control devices.
Wet scrubbers are used to control gaseous ammonia, chlorine
and fluorine, and particulate emissions from the ammoniator-
granulator. Plants that do not exceed local state emission
standards use only cyclones to collect particulate emissions
from the ammoniator-granulator, dryer, and cooler. Occa-
sionally (<10% of the plants) baghouses are used to further
remove particulate emissions. Other plants use both cyclones
and wet scrubbers, the cyclone exhausts being fed into the
wet scrubber. It is estimated that 60% of the ammoniation-
granulation plants use either wet scrubber systems or a
combination of wet scrubbers and cyclones. Cyclones are used
to control particulate emissions at the remaining 40% of the
plants.
Various types of wet scrubbers are used at these plants to
collect both gaseous and particulate emissions. Wet scrubber
designs vary from the medium efficiency (85%) wet scrubbers
to the high efficiency (99%) packed bed and venturi scrubbers,
Medium efficiency wet scrubbers are typically (about 40% of
the plants with scrubbers) used by the smaller plants
(<45 x 103 metric tons/yr) primarily because of the higher
capital and operating costs of high efficiency collection
systems. These wet scrubbers include impingement type
(Figure 32) and cyclonic type (Figure 33) devices.
Water or phosphoric acid is used in these devices as the
scrubbing solution and the resulting slurry is recycled into
the ammoniator-granulator or sold as low grade liquid
fertilizer. The pressure drop across these scrubbers ranges
117
-------
DIRTY GAS
INLET
LIQUID
SUPPLY
OVERFLOW
SYSTEM
Figure 32. Impingement type scrubber19
Reprinted by permission of Modern Plastics Encyclopedia, McGraw-Hill, Inc.
118
-------
LIQUID INLET
DIRTY
GAS
INLET
CLEAN GAS OUTLET
MANIFOLD
JET SPRAY BOX
Figure 33. Cyclonic scrubber19
Reprinted by permission of Modern Plastics Encyclopedia, McGraw-Hill, Inc.
\
119
-------
from 1.24 kPa to 2.5 kPa (5 in. to 10 in. of water). These
scrubbers are approximately 85% efficient at collecting
ammonia, fluorine, chlorine, phosphorus and particulate
emissions.
Higher efficiency wet scrubbers are more common (at about 60%
of the plants with scrubbers) at the larger (>45 x 103 metric
tons/yr) ammoniation-granulation plants because of the
economical advantage of collecting ammonia losses and
recycling them back into the process. These plants can also
better afford the expense of the control devices. Examples
of these wet scrubbers include two-stage cyclonic scrubbers
(Figure 34), venturi cyclonic scrubbers (Figure 35), and
packed bed scrubbers (Figure 36).
The two-stage wet cyclonic scrubbers are relatively simple
in design and construction, and have relatively low pressure
drop characteristics, 1.24 kPa to 3.7 kPa (5 in. to 15 in.
of water). They are capable of collecting approximately
>95% by weight of ammonia, particulates and ammonium chloride
aerosols greater than 3 ym. These scrubbers are also used
as primary collection systems in plants which require both
primary and secondary controls.
Packed bed and venturi type scrubbers are much more efficient
collection devices than are the wet scrubbers. At a pressure
drop ranging from 3.7 kPa to 12.4 kPa (15 in. to 50 in.
of water) they can collect greater than 99% of the ammonia,
chlorine, fluorine and phosphorus vapors as well as particu-
lates and ammonium chloride aerosols greater than approximately
1.0 ym. The operating parameters for a venturi cyclonic wet
scrubber handling the emissions from the ammoniator-granulator
at a large plant are shown in Table 33.
120
-------
GAS OUTLET
PHOSPHORIC ACID
OR WATER
GAS INLET
WATER OUTLET
Figure 34. Two-stage cyclonic scrubber
121
-------
DIRTY GAS INLET
CLEAN GAS
OUTLET
SEPARATOR
WEIR BOX
THROAT
DRAIN
Figure 35. Venturi cyclonic scrubber19
Reprinted by permission of Modern Plastics Encyclopedia, McGraw-Hill, Inc,
122
-------
COOLER
OUCT
ENTRAIN MENT REMOVAL BED
PORC RASH IG RINGS
SUPPORTED BY 304 S S * 8 WIRE
I*) SPHAV PIPES
MCED EVENLY
TONGUE AND
GROOVE REDWOOD
SCRUBBING
BED
PORL. iNTALOX
SADDLES
SUPPORTED BY
304 S S « 8 WIRE
PLATE
RECIRCULATION LINE
RECYCLE PUMP DEMING
CENT S S TRIM 8 IMPELLER.
SPMAY PIPE
STEEL MOD-
TYPICAL SPRAY NOZZLE
Figure 36. Packed bed scrubber19
i
Reprinted by permission of Modern Plastics Encyclopedia, McGraw-Hill, Inc.
123
-------
Table 33.
OPERATING CONDITIONS FOR A VENTURI
CYCLONIC WET SCRUBBER56
Plant capacity, metric tons/day
Process weight, metric tons/hr
Gas to scrubber
Flow, m3/min
Temperature, °C
Moisture, vol. %
Particulate, kg/hr
Ammonia, kg/hr
Ammonia , ppm
Gas from scrubber
Flow, m3/min
Temperature, °C
Moisture, vol. %
Particulate, kg/hr
Ammonia, kg/hr
Ammonia , ppm
Particulate efficiency, wt. %
Ammonia efficiency, wt. %
Scrubber 1
900
38
850
82
35
91
152
1,350
850
73
36
3.6
1.5
13.4
98
99
Scrubber 2
1,450
61
1,360
82
35
145
242
1,350
1,360
73
36
5.8
2.4
13.4
98
99
The particular disadvantages of the high efficiency collec-
tion devices are their high capital and operating costs and
large maintenance requirements. The cost of a venturi
cyclonic or venturi throat packed bed system can be as high
as 50% of the capital cost of the mixing plant.22 Large
maintanance costs are a result of the high pressure drops
required coupled with 82°C gases and acidic solutions.
The Industrial Gas Cleaning Institute has computed the costs
for high efficiency wet scrubbers which are applied to emis-
sions from ammoniation-granulation plants.56 The data input
and results of their 1973 survey are shown in Appendix H.
56Air Pollution Control Technology and Costs in Seven Selected
Areas, Phase I (Phosphate Industry). Prepared by Industrial
Gas Cleaning Institute, Washington, for the U.S. Environmental
Protection Agency. March 1973. 200 p.
124
-------
The collector plus auxiliary equipment cost for two-stage
cyclonic scrubbers ranges from $50,000 to $115,000; for ven-
turi cyclonic scrubbers, from $40,000 to $115,000; and for
packed bed scrubbers, from $20,000 to $90,000. The values
vary depending on the gas flow rate, which ranges from 280
to 1,700 m3/min.
Baghouses are occasionally (<20 plants) used at ammoniation-
granulation plants to remove particulate emissions from
various sources in the plant. Their relatively high capital
cost, which can be as high as 50% of the total plant invest-
ment, prevents many plants from installing baghouses.
Many types of bag filters are applicable to ammoniation-
granulation plants (Table 34). Since the exhaust gas
temperatures are below 104°C, temperature requirements
of the bag filter pose little problem in material selection.
The most important selection criterion is chemical resistance
Due to the chlorine in the emissions, the bags must be acid
resistant. Therefore, cotton and nylon bags cannot be used
in these plants.
A major problem associated with baghouses is the necessity
to maintain the temperatures in the baghouse above the dew
point to prevent moisture condensation, which causes caking
on the filters.9 This problem is especially prevalent at
ammoniation-granulation plants because of the high (30% to
50%) moisture content of the exhaust gases from the dryer.
B. BULK BLENDING PLANTS
1. Process Modifications
Particulate emissions at bulk blending plants are fugitive
in nature and result from materials handling and transfer
125
-------
Table 34. CHARACTERISTICS OF VARIOUS BAG FILTERS
Fabric
Acrylic
Dacron®
Glass
Polypropylene
Nomex®
Orion®
Teflon®
Maximum
operating
temperature, °C
121
135
288
93
218
135
218
Mechanical
resistance to
abrasion
Fair
Good to
excellent
Poor
Excellent
Excellent
Good
Fair
Chemical resistance to
Acid
Good
Excellent
Good
Excellent
Good
Excellent
Excellent
Alkali
Fair
Good
Good
Excellent
Good
Fair
Excellent
Solvents
Excellent
Excellent
Excellent
Good
Excellent
Excellent
Excellent
NJ
-------
operations in the blending plant building. The fugitive
building emissions that escape through doors and windows
can be lowered by reducing the amount of emissions inside
the building. One method is to apply dust depressing agents
such as water, liquid fertilizer (11-37-0), and motor oil to
the raw material and mixed fertilizer. Approximately 5% of
the bulk blend plants use this control method. Experts at
TVA conducted air sampling tests around the mixer and bagging
machine at a bulk blending plant to determine the effect of
adding 10-34-0 to the fertilizer as a dust depressant.26
The results of the test, given in Table 35, show that
addition of 1% of 10-34-0 reduced dust discharges from the
mixer to 12 mg/m3 from 25 mg/m3, and those from the bagging
machines to 11 mg/m3 from 282 mg/m3.
A sprayer bar installed in the rotary-drum mixer, as shown
in Figure 37, has been suggested by personnel at TVA as a
means of applying the binding agent to the fertilizer. A
simpler technique is to hand spray the mixed fertilizer as
it flows from the mixer to the bagging machine or elevator.
This hand spraying method can be used to spray the raw
materials before entry into the rotary mixer to reduce dust
emissions in other areas of the building.
Lightweight oils and used motor oils can also be utilized
as dust depressing agents. However, the application of oil
to any fertilizer mixture containing more than 60% ammonium
nitrate is not recommended because of the potential explosion
hazard. Spraying 4 kg to 9 kg of lightweight oil per
megagram of diammonium phosphate fertilizer has been reported
to reduce fugitive dust emissions to 10 mg/m3 around the
mixer.26
127
-------
Table 35. EFFECT OF 10-34-0 IN DEPRESSING DUST
IN BULK BLEND PLANT26
Sample
point
b
Mixer
Mixer
Mixer
Mixer
Mixer
Mixer
Mixer
Bagger
Bagger
Bagger
Bagger
Sample
no.
1
2
1
2
1
2
3
1
1
2
3
10-34-0,
g/kg
5.8
5.8
11.5
11.5
None
None
None
10.0
None
None
None
Air
sampled,
m3
7.9
8.1
7.9
9.7
8.6
7.9
8.1
12.5
8.9
9.8
8.8
Dust concentration
Per sample,
mg/m3
" I
23 J
10 }
13 t
24 ,
20 [
32*
II6
228)
278 (
340
a
Per test,
mg/m3
19
12
25
11
282
Average of dust concentration of samples.
Mixer samples obtained 2.4 m horizontally and 0.6 m vertically
upward from mixer discharge door.
•*
"Bagger samples obtained 2.4 m horizontally and 0.6 m vertically
downward from bagging machine operator platform.
Weighted average of conditioner applied during Tests 1 and 2.
a
"Considerably less dust falling off overhead conveyor belt into
air during this test.
128
-------
to
VD
DUST
{DEPRESSANT
" 10-34-0
ROTAMETER
FLOW CONTROL
STRAINER
Figure 37. Dust depressant application system
-------
2. Pollution Control Devices
The majority (99%) of the bulk blend plants do not use any
pollution control equipment because their emissions are
below local state emission standards. The plants that do
have control devices are located in conjunction with
ammoniation-granulation plants and their emissions are
jointly controlled. Dry cyclones and baghouses are used to
collect the particulate emissions in these instances. Some
bulk blend operators have put skirts around the railroad
cars to reduce fugitive dust emissions when the cars are
being unloaded.
Engineers at the fertilizer division of TVA have designed
systems to control particulate emissions at bulk blending
plants in case they are required. Most of their solutions
relate to the materials handling and conveying operations.
One suggestion is to avoid the use of pneumatic conveying
equipment unless the granular materials are treated with a
dedusting agent or effective collectors are provided to
remove dust from the discharged air. Inclined screw con-
veyors are recommended to convey materials from hopper-
bottom railroad cars to a shuttle conveyor for distribution
into storage bins. Telescoping chutes can be used to dis-
charge the material into the bins without causing excessive
dust emissions. This system is illustrated in Figure 38.
It is recommended that the inclined screw conveyor be
connected to the shuttle conveyor by a flexible sock
arrangement.2 7
An alternate system for transferring raw materials from
railroad cars to storage bins is illustrated in Figure 39.
The material is transferred into the storage bins through a
130
-------
CENTRIFUGAL
PUMP
Figure 38. Bulk blend plant equipped with dust controls23
-------
SKIRT AROUND
CAR FOR DUST
CONTROL
VANE TYPE
SEAL WINDOW
(AT LOADING v
BOOT)
Figure 39. Alternative dust control systems
132
-------
split belt bin opening arrangement. Openings in the bin are
closed by overlapping flexible material, such as belting
material. A plow attachment on the shuttle conveyor, shown
in Figure 40, is used to separate the flexible material to
provide an opening for filling the bin. In addition, flexi-
ble ourtains or metal doors are recommended on the front of
the storage bins to prevent further dust emissions. Materi-
als from the storage bins are removed by a front-end loader
which discharges them into an elevator. An exhaust hood
should be installed above this elevator boot to feed any dust
discharged at this point into the exhaust system. Ventila-
tion rates recommended by the ACGIH for bulk blending equip-
ment are shown in Table 36.57
Bucket elevators are another source of particulate emissions
at fertilizer blending plants. Centrifugal discharge eleva-
tors, shown on the left side of Figure 41, should be replaced
with product discharge elevators, shown on the right side of
Figure 41. The centrifugal discharge type is usually a
high-speed bucket elevator and a considerable amount of
material does not empty from its buckets. If the materials
are excessively dusty, dust is emitted from the elevator
boot. The low-speed product discharge elevator has two
strands of chain snubbed back by an idling sprocket and
rounding the head sprocket. This arrangement gives an almost
complete upturn of the buckets, allowing them to empty
completely through the discharge chute. Practically no
material showers down to the boot of the elevator. In addi-
tion, some companies have found that sealing the boot of the
elevator, as shown in Figure 42, eliminates dust emissions.27
57Trayer, D. M. Environmental Control in Bulk Blending Plants
1. Industrial Hygiene Aspects. In: TVA Fertilizer Con-
ference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-62. August 1973. p. 47-58.
133
-------
Figure 40. Bin-filling arrangement27
134
-------
Table 36. VENTILATION RATES FOR BULK BLENDING EQUIPMENT57
Dust point
Air flow requirements
u»
Mixer
Bucket elevator
Conveyor belt transfer
For belt speed of 61 m/min
For 1.0 m material fall
For enclosed conveyor
For very dusty materials
Screens
Flat deck hood openings
Cylindrical screens
Hoppers
Manual loading
Belt fed
Screw conveyors
Bag filling
Bag tube packer
61-91 m3/min-m2 of open face area
30 m3/min-m2 of casing cross section (takeoffs top
and bottom for elevators >9 m high)
33 to 46 m3/min-m of belt width
Add 20-28 m3/min
Add 46-61 m/min indraft at all openings
1.5 to 2 times stated flow rate
61 m3/min-m2 of hood opening (at least 15 m3/min-m2
screen area^)
30 m3/min-m2 of circular screen cross section (at
least 122 m3/min-m2 of enclosure opening)
46 m3/min-m2 of face area
See conveyor belt transfer above (provide at least
O O
61 mVmin-m opening)
61 m3/min takeoffs on 9 m centers
305-457 m3/min
152 m3/min filling tube
152 m3/min at feed hopper
290 m3/min at spill hopper
TVA
has found that 15 m3/min-m2 of screen area is sometimes insufficient for good control at screens.
-------
CENTRIFUGAL DISCHARGE PRODUCT DISCHARGE
Figure 41. Bucket elevators used in bulk blending plants26
136
-------
Figure 42. Vane type seal for bucket elevator23
137
-------
C. LIQUID MIX PLANTS
1. Process Modifications
The hot mix pipe reactor process, recently commercialized,
eliminates the hot mix reactor tank, thus reducing the
amount of possible emissions from hot mix plants. In 1974,
there were 100 pipe reactors in operation (at 3.6% of liquid
mix plants), and more were planned.31
2. Pollution Control Devices
The pipe reactor plants are equipped with wet scrubbers.
When a separate mix tank is used, the packed bed wet scrubber
is mounted on top of the mix tank. Either water, partially
cooled product, or both are used as scrubbing solutions to
remove approximately 95% of the ammonia, chlorine, fluorine,
particulate and ammonium chloride emissions. A demister is
placed on top of the scrubber to further reduce aerosol
emissions.
In the tower design pipe reactor plant, the scrubber is an
integral part of the tower. The packed bed scrubber acts
not only to reduce air emissions, but serves as the cooling
section. The packed bed scrubber-cooler and the demister
unit on top of the tower collect approximately 95% to 99% of
all emission species.
Few fluid fertilizer producers using the open tank technique
have received complaints concerning ammonia emissions from
their plants.19 The installation of a hood system and packed
bed wet scrubber, such as shown in Figure 43, has been used
to control these emissions. Exhaust gases from the hot mix
open tank reactor and from the liquid storage tanks are
138
-------
blown into the bottom of a packed bed tower by exhaust
fans. Phosphoric acid or water is sprayed onto the packing
of the tower and is usually recirculated until it has a
nitrogen content of about 3% to 4% and a P2O5 content of
about 16%. This partially neutralized phosphoric acid solu-
tion is used to produce liquid mixtures.
VENT
VENT
, RECYCLE
HjP04
ISTORAGE
TANK
VENT
PRODUCT
STORAGE
I I DEMISTER
1 [ /
LIQUID
PUMP
> X « « X X X
X X * X X X
X X X X X XX
X X X X XX
X X X X X XX
X X X X X X
GAS FAN
Figure 43. Suggested fume scrubbing system for
fluid plant
Reprinted by permission of Modern Plastics Encyclopedia, McGraw-Hill, Inc.
139
-------
SECTION VI
GROWTH AND NATURE OF THE INDUSTRY
Fertilizer consumption in the U.S. in 1973 was 39.1 x 106 metric
tons, an increase of 4% above the 37.4 x 106 metric tons
consumed during 1972. Consumption of mixed fertilizers
containing two or all three primary plant nutrients accounted
for 52% (20.3 x 106 metric tons) of the total, an increase of
4% over the preceding year. The past and expected future growth
in the fertilizer industry is shown in Figure 44.58
Of the 20.3 x 106 metric tons of mixed fertilizers consumed,
ammoniation-granulation plants produced 45%, bulk blending
plants produced 32%, and liquid mix plants produced 23%.
Figure 45 shows the mixed fertilizer market split among these
three types of mixing plants since 1962.
In 1973, there were approximately 195 ammoniation-granulation
plants, 5,640 bulk blend plants, and 2,678 liquid mix plants.
The number of plants is not expected to increase by more
than 6% over the next 4 years. The existing plants are ex-
pected to increase their capacities before they increase in
numbers. As more compatible means are found for applying
herbicides to fertilizers and this type of product becomes
accepted by farmers, the number of liquid mix and bulk
blending plants will increase.
58Wheeler, E. M. Marketing Trends. In: TVA Fertilizer
Conference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-78. August 1974. p. 88-91.
141
-------
CO
o
o
O
Q_
^
ZD
CO
o
O
CHL
LU
M
1960
1980
Figure 44. Fertilizer consumption from 1960 to 1980
142
-------
100
. 90
t 80
1 70
LU
3 60
f—
LU rn
LJ- 50
Q
LlJ
1 4°
Ll_
o
o
a:
30
20
10
0
AMMONIATOR-GRANULATOR
BULK BLENDING
GROWTH
LIQUIDMIX
1962 1965
1970
YEAR
1975
1980
Figure 45. Portion of the mixed fertilizer market
shared by the three types of mixing plants5
143
-------
Forecasts for the supply and demand of nitrogen,
potash are shown in Figures 46, 47, and 48, respectively.5
On the supply side, nitrogen-fertilizer and ammonia producers
are plagued by continuing problems in getting enough natural
gas feedstock. While the lack of natural gas is an immediate
short-term (3 years) crisis, it could turn into a major long-
term problem depending on the policies established by the
federal government to solve the nation's energy supply problem.
Additionally, if all the nitrogen plants slated for construc-
tion are built, there could be an overcapacity by 1978 or
1979.5
Supplies of potash are also being reduced because new and
higher tax regulations on potash are being imposed by Canada,
the major supplying country. The province of Saskatchewan
has instituted a "'reserve tax" on potash, designed to dis-
courage excessive exploitation of resources. The problem
is that as the price of potash increases, so does the tax
rate.59
Phosphate fertilizer producers are the least concerned about
the supply of raw materials. While the price of phosphate
rock is increasing, there seems to be a plentiful supply.
With new plants coming onstream, supply and demand should be
in balance in 1975, and will continue that way into the
1977-1978 crop year.
Fertilizer demand is still outstripping supply, but at a
slower pace. Lower cattle prices and a depressed citrus
market in Florida and Texas are causing farmers to purchase
less fertilizer. Also, the depressed textile market is
59Koepke, W. E. Future Potash Supply. In: TVA Fertilizer
Conference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-78. August 1974. p. 27-34.
144
-------
17
oo
o
o 15
i—i
a:
LU
vo 13.
o 1J
i "
9-
Q-
Q.
O
00
TOTAL CAPACITY
\
TOTAL DEMAND
SUPPLY AT VARIOUS
OPERATING RATES
\
FERTILIZER DEMAND
8.2
7.3-
OO
I
(_>
t—I
o:
LU
vo 6.3
o
in
O
c? 5.4
| 4.5
oo
1972 1974 1976 1978
1980
3.6
EXPORT LEVELS
(MILLIONS) 2.0'
SUPPLY AT VARIOUS
OPERATING RATES
FERTILIZER DEMAND
1972
1974
1976
1978
1980
Figure 46. Nitrogen supply
forecast for the U.S.^
Figure 47. Phosphate supply
forecast for the U.S.5
5.^
oo
1 7>3'
O
t— i
o;
LU 6.3-
s:
IXD
0
o 5-4-
CM
^
U_
O
>j 4.5-
o.
Q.
Z3
OO
3 fi.
EXPORT LEVEL
(MILLIONS)
SUPPLY AT VARIOUS \^^%,^ **
CANADIAN OPERATING LEVELS A"
t-^.^.. ..-A
V--'' V
-A, >"
" \:"""
^'* -^
ii -. f* 5OT ^
-^"'' ^''
^
^ FERTILIZER DEMAND
^
1972 1974 1976 1978 1980
Figure 48. Potash supply
forecast for the U.S.5
145
-------
causing farmers to plant less cotton and therefore use less
fertilizer.60
At ammoniation-granulation plants, urea ammonium phosphate
(UAP) is expected to start replacing ammonium nitrates and
sulfates, possibly by the late 1970's.61 UAP is produced by
combining ammonia and merchant-grade wet-process phosphoric
acid in an ammoniator-granulator. Concentrated urea solution
is then added to the melt.
Since fertilizer manufacture accounts for 54% of all sulfuric
acid consumption in the U.S., much interest has been shown
by the fertilizer industry in SO2 recovery from coal-fired
steam plants.61 Eventually, the economic burden of SO2 re-
covery may be lessened by a closer tie-in to fertilizer
production, with the ultimate possibility of sharing process
steps. Granulation plants and liquid mixing fertilizer
plants may be affected by this process sharing concept.
One trend that seems fairly certain into the 1980's is the
growing importance of urea as a straight fertilizer material
and for use in mixed and compounded fertilizers.61 Urea
made up about 19% of the world's total nitrogen production
in 1967 and 30% in 1973. Use of granular urea in bulk
blenders should become increasingly attractive because urea
permits delivery of higher nitrogen quantities to the crops
using less fertilizer material.
60Nilsen, J. M. Fertilizer Outlook "Iffy." Chemical
Engineering. £2 (6):28-29, March 1975.
6 kelson, L. B. Trends in Technology. In: TVA Fertilizer
Conference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-78. August 1974. p. 92-95.
146
-------
Sulfur-coated urea, a controlled-release nitrogen product
developed by TVA, appears to hold a lot of promise and may
come into limited production by the late 1970's. This pro-
cess involves spraying preheated urea with molten sulfur in
a rotating drum. A wax sealant is applied on top of the
sulfur coating to seal pinholes and cracks that would affect
the controlled release properties. Finally, a coating dust
is applied to the product to reduce its stickiness.61 This
material should be useful in bulk blending because of the
larger granule sizes and because the sulfur coating prevents
undesirable chemical reactions with superphosphate. Compared
to uncoated urea, it has greater crushing strength and resis-
tance to abrasion and it is not as hygroscopic.
An important consideration in the future growth of fluid
fertilizers is the role of suspensions. About half of the
fluid fertilizer producers now make suspensions, which
account for about one-third of their total tonnage.61 A net
balance seems to be in favor of liquid mixed suspension ferti-
lizers as compared to clear liquid mixes.
In addition, there seems to be a growing trend toward the
use of computers both for management practices and process
quality control.62 Until recently this type of computer
network was available only to the largest companies. However,
this service is now available to the small fertilizer mixing
plants as a result of new remote terminal and computer time-
sharing technology. For about $15/hour of actual computer/
terminal use, the small mixing plant can rent the full
services of a $100 million computer network.62
62Boughner, R. T., and J. L. Nevins. Some Management Trends
in the 1980's. In: TVA Fertilizer Conference. Tennessee
Valley Authority. Muscle Shoals, Alabama. Bulletin Y-78.
August 1974. p. 82-87.
147
-------
SECTION VII
APPENDIXES
A. Granular Raw Materials Consumed at Fertilizer
Mixing Plants in the U.S.
B. Raw Data used to Calculate Emission Factors for
Ammoniation-Granulation Plants
C. TLV's for the Raw Materials, Secondary, and Micronutri-
ents used by Fertilizer Mixing Plants
D. Details of Sampling Presurvey at Bulk Blending Plants
E. TLV and LD50 Values for Selected Herbicides (Active
Ingredients) used at Fertilizer Mixing Plants
F. Data used to Establish Emission Factors for Hot Mix
Liquid Mix Fertilizer Plants
G. Mass of Particulate Emissions from Fertilizer Mixing
Plants
H. Capital and Operating Cost for High Efficiency Wet
Scrubbers
149
-------
APPENDIX A
GRANULAR RAW MATERIALS CONSUMED AT FERTILIZER
MIXING PLANTS IN THE U.S.
Granular raw materials
Normal superphosphate
(<22% P205)
Triple superphosphate
U40% P205)
Monoammonium phosphate
NHi1.H2POtf
Diammonium phosphate
(NH4) 2HPO4
Ammonium nitrate
NH^NOs
Ammonium sulfate
(NHiJ 2SO4
Urea, prilled
NH2CONH2
Potash
K2O
Dried sewage sludge
Crushed limestone
CaCO3
Dolomite clay
Sand
SiO2
Grade
0-20-0
0-46-0
11-48-0
18-46-0
35.5-0-0
21-0-0
45-0-0
5.6-6.2-0
Particle
size
distribution
mm
1
1
1
1
1
1
1
1
1
0.6
0.4
0.3
1
1.0
0.3
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
4
>4
<1
4
>4
4
>4
<1
4
4
<1
4
<1
4
<1
3
>3
<1
4
1
0.6
0.4
<0.3
4
<1
1.7
>1. 7
<1.0
1.0
>1.0
<0.3
Percent
27
14
59
99
1
93
1
6
100
96
4
93
7
96
4
59
36
5
3
18
13
42
24
88
12
89
5
6
95
1
4
150
-------
APPENDIX B
RAW DATA USED TO CALCULATE EMISSION
FACTORS FOR AMMONIATION-GRANULATION PLANTS
151
-------
Table B-l. PLANT SOURCE TEST DATA
01
to
Plant
A
B
C
Production
rate
22.7 metric
tons/hr
(25 tons/hr)
680 metric
tons/day
(750 tons/day)
Unknown
Source of
emissions
Total plant
Dryer and
cooler
Total plant
Dryer
Cooler
Total plant
Uncontrolled emission factor, a gAg (pound/ton)
NH3
0.223
(0.446)
0.164
(0.329)
Total
chlorine
Total
fluorine
0.00390
(0.00781)
0.00272
(0.00545)
0.00465
(0.00930)
0.0023
(0.0046)
0.0027
(0.0054)
0.0002
(0.0005)
0.0028
(0.0057)
0.0080
(0.0161)
0.0127
(0.0255)
0.0059
(0.0119)
0.0080
(0.0161)
0.0061 .
(0.0123)
0.0015-0.008
(0.003 -0.017)
0.015 -0.025
(0.029 -0.05)
0.001 -0.004
(0.003 -0.008)
Total
phosphorus
0.0062
(0.0124)
0.0011
(0.0022)
0.0215
(0.0430)
Particulate
0.223
(0.446)
0.52
(1.05)
0.39
(0.77)
0.25-0.5
(0.5 -1.0)
0.47
(0.9J)
0.21-0.44)
(0.42-0.87)
0.34
(0.68)
0.27-0.51
(0.54-1.02)
Controls used
and efficiency
Cyclonic scrubber
and venturi
scrubber, 99%
Cyclone, 80%
Wet scrubber, 85%
Cyclone
Cyclone
Wet scrubber, 90%
Individual emission factor entries represent separate samples taken.
-------
Table B-l (continued). PLANT SOURCE TEST DATA
U>
Plant
D
E
Production
rate
Unknown
Unknown
Source of
emissions
Ammoniator-
granulator
Dryer
Cooler
Total plant
Ammonia tor-
granulator
Dryer
Total plant
Uncontrolled emission factor, a g/kg (pound/ton)
NH3
0.58
(1.15)
0.18
(0.37)
0.07
(0.14)
0.06
(0.13)
0.092
(0.185)
0.087
(0.175)
0.167
(0.335)
0.07
(0.15)
0.25
(0.50)
0.15
(0.30)
0.07
(0.15)
0.07
(0.15)
0.15
(0.30)
0.26
(0.53)
0.19
(0.38)
0.04
(0.08)
0.04
(0.08)
0.04
(0.08)
Total
chlorine
Total
fluorine
0.0027
(0.0055)
0.0013
(0.0026)
0.0013
(0.0026)
0.022
(0.0440)
0.0096
(0.0193)
0.0027
(0.0055)
0.0069
(0.0138)
0.0041
(0.0083)
0.0027
(0.0055)
Total
phosphorus
Particulate
Controls used
and efficiency
Wet scrubber
Wet scrubber
Wet scrubber
Wet scrubber, 90%
Cyclone and wet
scrubber, 99%
Individual emission factor entries represent separate samples taken.
-------
Table B-l (continued). PLANT SOURCE TEST DATA
m
Plant
F
G
H
Production
rate
Unknown
21 metric
tons/hr
23 tons/hr)
13.5 metric
tons/hr
(15 tons/hr)
Source of
emissions
Total plant
Ammoniator-
granulator
Total plant
Ammoniator-
granulator
Dryer
Cooler
Total plant
Uncontrolled emission factor, a g/kg (pound/ton)
NH3
0.15
(0.30)
3.37
(6.74)
2.50
(5.00)
3.37
(6.74)
0.19
(0.39)
1.37
(2.73)
2.37
(4.74)
0.54
(1.09)
0.85
(1.7)
1.6
(3.2)
0.45
(0.91)
0.63
(1.26)
0.32
(0.64)
0.70
(1.4)
0.8
(1.6)
0.13
(0.27)
0.75
(1.5)
1.2
(2.4)
3.0
(6.1)
Total
chlorine
0.0196
(0.0391)
0.0805
(0.1609)
0.0174
(0.0348)
0.0021
(0.0043)
0.035
(0.070)
0.078
(0.156)
0.018
(0.036)
Total
fluorine
0.0025
(0.005)
<0.001
(<0.002)
0.002
(0.003)
<0.0009
(<0.0017)
0.0002
(0.0004)
0.002
(0.004)
0.004
(0.008)
0.0018
(0.0035)
Total
phosphorus
0.0009
(0.0019)
0.0009
(0.0019)
0.0019
(0.0038)
0.0006
(0.0011)
0.1135
(0.2271)
0.0371
(0.0742)
0.0170
(0.0341)
Particulate
0.036
(0.073)
0.031
(0.062)
0.094
(0.188)
0.13
(0.25)
0.23
(0.45)
0.09
(0.18)
0.07
(0.13)
0.035
(0.07)
0.1
(0.20)
2.7
(5.4)
1.9
(3.8)
0.07
(0.13)
0.14
(0.28)
0.23
(0.45)
0.47
(0.93)
Controls used
and efficiency
Cyclone and
venturi scrubber,
99*
Wet scrubber, 85%
Wet scrubber, 90%
Individual emission factor entries represent separate samples taken.
-------
Table B-2. STATISTICAL ANALYSIS OF EMISSIONS FROM
AMMONIATION-GRANULATION PLANTS FOR 95% CONFIDENCE LIMITS
Emission source
category
Materials storage
and handling
Ammoniator-
granulator
Dryer and cooler
Screen and oversize
mill
Bagging and loading
Total plant
Statistical
parameter
x, gAg
Precision
x, gAg
11
s (x) , gAg
s (x) , gAg
*0. 05, n-l
Precision
x, gAg
n
s (x) , gAg
s (x) , gAg
tQ. 05, n-l
Precision
x, gAg
Precision
x, gAg
Precision
x, gAg
n
s (x) , gAg
s (x) , gAg
to. 05, n-l
Precision
Emissions species
Ammonia
0
N.A.
0.503
7
0.564
0.213
2.477
±104%
0.316
16
0.262
0.065
2.131
±44%
0
N.A.
0
N.A.
0.819
N.A.
N.A.
N.A.
N.A.
±66%
Total
chlorine
0
N.A.
0.030
4
0.035
0.018
3.182
±186%
0.028° .
N.A.
N.A.
N.A.
N.A.
±175%
0
N.A.
0
N.A.
0.044
3
0.031
0.018
4.303
±175%
Total
fluorine
0
N.A.
0.0013
7
0.0008
0.0003
2.447
±57%
0.0083
11
0.0086
0.0026
2.228
±70%
0
N.A.
0
N.A.
0.0096
N.A.
N.A.
N.A.
N.A.
±61%
Total
phosphorus
0
N.A.
0.0011
4
0.0006
0.0003
3.182
±87%
0.0316°
N.A.
N.A.
N.A.
N.A.
±133%
0
N.A.
0
N.A.
0.0327
6
0.0415
0.017
2.571
±133%
Particulate
0.53
±300%
0.175
2
0.070
0.049
12.706
±356%
0.23
12
0.173
0.05
2.201
±48%
0.253
±300%
0.253
±300%
1.40
N.A.
N.A.
N.A.
N.A.
±300%
Emission factor based on engineering estimate and could vary by a factor of three.
N.A. = not applicable.
Emission factor calculated by subtracting ammoniation-granulation emissions from measured
total plant emissions.
155
-------
APPENDIX C
TLV'S FOR THE RAW MATERIALS, SECONDARY, AND
MICRONUTRIENTS USED BY FERTILIZER MIXING PLANTS48
Material
Ammonia , anhydrous
Ammonium nitrate
Ammonium sulfate
Ammonium (nitrate + sulfate)
ACGIH toxicity ratings
Acute
High
Moderate
Moderate
Moderate
Ammonium (phosphate + nitrate)Moderate
Diammonium phosphate
Phosphoric acid
Urea
Urea ammonium nitrate
Sulfuric acid
Potassium chloride
Alumina silicates (zeolite)
Calcium carbonate
Calcium silicates
Diatomaceous earth
Kaolin
Surfactants
Moderate
Moderate
Slight
Unknown
Moderate
Moderate
Slight
Slight
Slight
Slight
Slight
Moderate
Chronic
Slight
Moderate
Unknown
Unknown
Unknown
Unknown
Moderate
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
TLV,a
g/m3
0.018.
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
0.001
(0.01)
(0.01)
0.001
(0.01)
(0.01)
0.010
(0.01)
(0.01)
0.010
(0.01)
Parentheses indicate an assigned TLV of 0.01 g/m3 because
values have not been established; in addition, the TLV
for nuisance dust is 0.01 g/m3.
156
-------
APPENDIX D
DETAILS OF SAMPLING PRESURVEY AT BULK BLENDING PLANTS
1. PLANT VISITS
Three fertilizer bulk blending plants were visited in order
to obtain firsthand information about the mixing operations,
to view the sources of emissions, and to locate a plant for
sampling. These three plants were located within an 80-km
radius of Dayton, Ohio and all were visited on 22 April 1975.
The plants are described below.
a. Plant A
The first plant visited had a 4.5 metric tons/hr capacity
ribbon mixer. The maximum daily plant capacity was
22.5 metric tons to 27 metric tons. This plant accomplishes
approximately 70% of its production in February and March,
and 30% during October and November.
The raw material, mixer, and loading operations were enclosed
in a building at this plant. A front-end loader dumped the
raw materials (usually 18-46-0, 45-0-0, 0-46-0, and potash)
into the mixer unit. After mixing, the material was dis-
charged onto a belt conveyor for transport to a spreader or
truck parked under a roof-covered, three-sided shed. At the
time of the visit no fertilizer was being mixed and it was
not possible to view the emissions which might issue from
the doors of the building.
b. Plant B
The second plant visited was equipped with a 2.7 metric
tons/hr capacity gravity-type mixer. The daily plant
157
-------
capacity was 18 metric tons to 22.5 metric tons and yearly
production periods were the same as those of Plant A.
Again, all the mixing operations (raw material storage, mixing,
and loading) were located in a building. The mixed fertilizer
was conveyed by screw conveyors to the loading area where
spreaders and trucks were parked under a roof-covered, two-
sided shed. During the visit this plant was not mixing
fertilizer.
c. Plant C
The third plant visited was newer in design than the other
two plants. It was equipped with a 3.6 metric tons/hr
capacity rotary-drum mixer. The daily maximum capacity
was approximately 45 metric tons.
The raw materials (18-46-0, 45-0-0, 0-46-0, and potash) and
mixing operations were all enclosed in a building. A front-
end loader was used to add the raw materials to the mixer
unit. The mixed fertilizer issued from the mixer onto a
belt conveyor for transport out of the building to the truck
or spreader parked under the belt conveyor discharge.
It was observed that small amounts of dust were emitted
during the filling of a truck when the discharge end of the
belt conveyor was about 1.2m above the truck. However, the
dust cloud was completely dispersed into an invisible plume
within 10 m of the truck. (Wind speed was <4.5 m/s (<10 mph) .)
In addition, a slight dust cloud issued from the doors of
the building when the front-end loader dumped prilled urea
(45-0-0) and potash into the mixer unit. No visible dust
passed through the doors when the other raw materials were
added. Therefore, it was decided to analyze the raw materials
to determine their particle size distribution.
158
-------
2.
RAW MATERIALS ANALYSIS
The four basic raw materials used at bulk blending plants
are: diammonium phosphate/ 18-46-0; prilled urea, 45-0-0;
triple superphosphate, 0-46-0; and potash, 0-0-60. Approxi-
mately 4.5 kg of each of the four granular materials were
collected from the raw material storage bins at Plant C,
placed in plastic bags, and transported to MRC for analysis,
The particle size distribution of the four raw materials
was obtained by using standard testing sieves and a Ro-Tap
testing sieve shaker. The series of sieves used for the
analysis are described below:
U.S. sieve Sieve Tyler equivalent
designation opening designation
2000
420
250
105
74
44
ym
pm
ym
vim
ym
ym
2000
420
250
105
74
44
ym
ym
ym
ym
ym
ym
9
35
60
150
200
325
mesh
mesh
mesh
mesh
mesh
mesh
The analysis procedure began with assembly of the six
sieves and the bottom pan. Then 300 grams of the material
was placed into the top sieve (2000 ym). This assembly was
placed in the Ro-Tap testing sieve shaker and shaken for
10 minutes. In order to obtain a weighable amount in the
bottom pan (particles <44 ym), the procedure was repeated
three times for each raw material species. Each repetition
involved removing the contents of the top sieve, adding
another 300 grams of the same material to the sieve, and
shaking for 10 minutes more. For the four tests on each
sample, a total of 1.2 kg of sample was used. It all cases
>99% of the raw material consisted of particles >2000 ym.
159
-------
The contents remaining on the sieves (250 ym, 105 ym, 74 ym,
44 ym, and pan) were emptied onto preweighed sheets of paper.
Both the paper and dust were weighed on a pan balance to the
nearest 0.0001 gram. The results of this analysis are given
in Table D-l.
Table D-l.
RESULTS OF SIEVE TEST FOR BULK BLENDING
PLANT RAW MATERIALS
Sieve
designation
>250 ym
250 ym
105 ym
74 ym
44 ym
Pan (<44 ym)
Contents remaining on sieves, g
Triple
super-
phosphate
0-46-0
1,199
0.0740
0.0871
0.0810
0.0771
0.0610
DAP
18-46-0
1,204
0.1010
0.0993
0.0451
0.0512
0.0230
Urea
45-0-0
1,203
0.0234
0.0553
0.0332
0.1077
0.1848
Potash
0-0-60
1,204
1.2217
1.5957
0.4860
0.2977
0.0377
3.
EMISSION FACTOR
Using the results of the particle size analysis, it is
possible to calculate worst-case emission factors for each
of the particle size ranges for the raw materials. Worst-
case emission factors are based on the assumption that all
of the particles within the specific size range are emitted
into the air during the loading operations. The results of
this analysis are given in Table D-2.
The percent of sample values were calculated by dividing
the weight of the particles captured on each screen by the
total weight of the sample used and then converting into
percentage. By scaling up this percentage value it is
160
-------
Table D-2. WORST-CASE EMISSION FACTORS FOR THE RAW MATERIALS
USED BY FERTILIZER BULK BLENDING PLANTS
Particle size
distribution,
ym
< 44
45 to 74
75 to 105
106 to 250
251 to 420
Triple
superphosphate
0-46-0
% of
sample
0.0051
0.0064
0.0068
0.0073
0.0062
g/kg of
product
0.051
0.064
0.068
0.073
0.062
DAP
18-46-0
% of
sample
0.0019
0.0042
0.0037
0.0082
0.0084
g/kg of
product
0.019
0.042
0.037
0.082
0.084
Urea, prilled
45-0-0
% of
sample
0.0154
0.0090
0.0028
0.0046
0.0019
g/kg of
product
0.154
0.090
•0.028
0.046
0.019
Potash
0-0-60
% of
sample
0.003
0.025
0.040
0.132
0.101
g/kg of
product
0.03
0.25
0.40
1.32
1.01
Emission
factor,
g/kg of
fertilizer
0.063
0.112
0.133
0.380
0.294
-------
possible to determine how many grams of particles in the
specific size range are found in a kilogram of the raw ma-
terial.
The values in Table D-2 show that the number of urea particles
<44 ym is an order of magnitude higher than the number of
such particles from any of the other three raw materials. In
addition, potash particles in the size range between 44 ym
and 74 ym are at least twice as numerous as particles in that
range for the other raw materials. This result explains why
small amounts of dust were emitted into the air when the
front-end loader at Plant C dumped urea and potash into the
mixer unit, but no dust cloud was visible when the other
two raw materials were dumped. The last column in Table D-2
gives a collective emission factor for all four raw materials
which is based on an equal proportion of these materials in
the final mixed fertilizer.
Stokes1 law for terminal settling velocities of spherical,
unit density particles was used to calculate how far the
particles in the various size ranges would travel before
settling to the earth. For a mean wind speed of 4.5 m/s
(10 mph) and an emission height of 6.1 m (20 ft), the dis-
tances calculated are: 105 ym, (4.5 ft); 74 ym, (9 ft); and
44 ym, (25 ft). These distances double if the wind speed is
doubled. The observed minimum distance from the loading
operations to the property line at this plant is approximately
30.5 m (100 ft).
Therefore, from Table D-2, for particles <44 ym, an emission
factor of 0.063 g/kg is justifiable. Using this size range
of particles to calculate an emission factor is in line with
the observation that a small cloud of dust was emitted at
Plant C during the loading operations, but the cloud settled
and dispersed into an invisible plume within 9.1 m (30 ft) of
the source.
162
-------
In the absence of emission source test data, it is impossible
to quantitatively assess an accuracy value for the emission
factor of 0.063 g/kg. However, based on the particle size
distribution of the raw materials, the sampling and analy-
tical technique, and the settling rates of the particles, it
is believed than an emission factor of 0.1 ± 100% g/kg is a
very good estimate of the true emission factor resulting from
handling, mixing, and loading the stored raw materials.
Since the samples were collected from the storage bins, prior
to the mixing and loading operations, the emission factor
indicates that half the emissions (0.05 g/kg) come from the
loading operations and half from fugitive building dust
emissions. It does not reveal how much of the 44 um particles
are lost when transferring the raw material from the rail-
road cars to the storage bins. Nor does this emission
factor reflect what portion of the larger particles are
broken down to the 44 ym particle size range due to material
handling, mixing, and loading operations. Therefore, on
a worst-case basis, an emission factor of 0.1 ± 100% g/kg is
used for each of the three emission sources at a bulk blend
plant (Table D-3). This procedure results in a total plant
particulate emission factor of 0.3 ± 100% g/kg.
Table D-3. EMISSION FACTORS FOR UNCONTROLLED PARTICULATE
EMISSIONS FROM FERTILIZER BULK BLENDING PLANTS
Emission source category
Materials storage and
handling
Loading operations
Fugitive building dust
Total plant
Emission factor,
g/kg
0.10 ± 100%
0.10 ± 100%
0.10 ± 100%
0.30 ± 100%
163
-------
'APPENDIX E
TLV AND LD50 VALUES FOR SELECTED HERBICIDES
(ACTIVE INGREDIENTS) USED AT FERTILIZER MIXING PLANTS
Type of herbicide
Organic herbicides:
Arsenicals
Phenoxys :
2,4-D
2,4,5-T
MCPA
Phenyl urea:
Diuron
Linuron
Fluometuron
Amides:
Propachlor
Propanil
Analap
Alachlor
Carbamates :
EPTA
Pebulate
Vernolate
Butylate
Dinitro group
Triazines:
Atrazine
Propazine
Simazine
Benzoics:
Amiben
Dicamba
Other organics:
Trifluralin
Nitralin
Dalapon
Norea
Fluorodifen
Toxicity
TLV,3
g/m3
0.0005
0. 01
0.01
(0.0005)
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
0.0002
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
(0.01)
(0.0005)
(0.01)
(0.01)
LD50-
oral rat,
mg/kg
800
370
500
700 to 800
3,400
1,500 to 4,000
8,900
1,200
1,384
8,200
1,200
1,630
1,120
1,780
4,659
10 to 50
3,080
5,000
5,000
5,620
2,100 to 3,700
>10,000
2,000
970
2,000
15,000
aParentheses indicate an assigned TLV (because a TLV has not
been established) based on the following criteria:
1. If LD50 < 1,000, then TLV = 0.0005 g/m3.
2. If LD50 > 1,000, then TLV =0.01 g/m3.
164
-------
APPENDIX F
DATA USED TO ESTABLISH EMISSION FACTORS FOR HOT MIX
LIQUID MIX FERTILIZER PLANTS36
Parameter
Test duration, hr
Reactor - forced draft blower
Pipe discharge (surface of liquid)
Production rate, metric tons/hr
Acid analysis, % total
Total P20S
Polyphosphate , PjOs
MgO
Solids
Temperature, °C
Acid
Melt (in pipe)
Ammonia
To pipe reactor
To vaporizer
10-34-0
Mix tank
From vaporizer
To storage
Product analysis, % of total
N
i'zOs
Polyphosphate
Specific gravity6 (20"C)
Stack condition
Opacity, *
Relative humidity, *
Stack loss data
Stack gas temperature, "C
Stack gas velocity, m/min
Sample volume corrected to
stack conditions, m3
Stack losses, (kg particulate)/hr
Total loss,J kg/hr
Gaseous ammonia
P20S
Fluorine
u
Total nitrogen
Test 1
3.5
Off
Below
18.6
70.6
33.3
0.45
Trace
35
304
41
5
78
71
50
9.4
34.2
73.4
1.388
Slight
Plumef
15
12
35
26
1.5
0.03
0.36
0.001
0.004
0.32
Test 2
3.5
Off
Above
18.6
70.6
33.3
0.45
Trace
33
302
34
4
75
70
47
9.7
34.6
69.4
1.392
No
Plume"
5
29
16
56
1.6
0.02
0.045
0.009
0.002
0.045
Test 3
1.6
On
Above
18.6
70.05
28.9
0.40
Trace
33
293
37
3
67
63
44
10.0
33.6
60.4
1.400
Heavy
Plume h
100
4
66
215
0.5
0.64
1.5
0.4
0.09
1.3
Test 4
2.5
On
Belowc
18.6
70.05
28.9
0.40
Trace
33
292
38
3
69
64
47
9.9
33.0
51.5
1.389
Heavy
Plumeh
100
34
61
159
0.5
3.31
0.36
1.0
0.9
0.9
a!42 m3/min forced draft blower mounted on side of reactor.
Pipe discharge melt above or below surface of liquid in mix tank.
°It is believed that the pipe discharged above the surface
of the liquid in the mix tank.
Non-orthophosphate.
ein parentheses, temperature at which specific gravity measured.
Plume very light, only about 0.6 m long.
^No plume, could look down in stack and see demister pad.
Plume several hundred yards in length.
An estimate of plume density; most states allow up to 20% opacity.
Combination of particulate and gaseous loss.
t.
Total nitrogen is the total of gaseous and combined nitrogen.
165
-------
APPENDIX G
MASS OF PARTICULATE EMISSIONS FROM FERTILIZER MIXING PLANTS
166
-------
MASS OF PARTICULATE EMISSIONS FROM FERTILIZER MIXING PLANTS
State
Alabama
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Number of plants
Ammon.-
gran.
8
0
3
5
0
0
0
9
11
0
0
17
13
17
4
6
3
0
0
0
4
9
3
Bulk
blend
39
9
81
21
72
7
12
62
101
4
72
749
370
833
156
150
200
6
57
7
117
400
39
Liquid
mix
32
11
25
53
3
1
4
27
100
2
3
281
213
277
210
22
24
0
4
9
7
125
9
State
production,
metric
tons/yr
(tons/yr)
473,890
(522,365)
28,940
(31,900)
276,010
(304,244)
348,070
(383,675)
87,870
(96,858)
9,740
(10,736)
20,560
(22,663)
538,760
(593,871)
800,720
(882,628)
7,980
(8,796)
87,870
(96,858)
2,133,030
(2,351,224)
1,394,780
(1,537,456)
2,222,870
(2,450,254)
721,780
(795,613)
490,900
(541,116)
411,170
(453,230)
6,900
(7,606)
72,310
(79,707)
23,260
(25,640)
333,860
(368,012)
1,093,080
(1,204,894)
200,670
(221,197)
Controlled
particulate
emissions,
metric
tons/yr
(tons/yr)
94
(104)
4
(4)
59
(65)
60
(66)
25
(27)
2
(3)
4
(4)
111
(123)
150
(165)
2
(2)
25
(27)
444
(490)
269
(297)
473
J522)
107
(118)
112
(123)
100
(110)
2
(2)
20
(22)
3
(4)
81
(89)
235
(259)
43
(48)
Total state
particulate
emissions, 53
metric
tons/yr
(tons/yr)
1,178,642
(1,299,231)
72,684
(80,121)
137,817
(151,917)
1,006,452
(1,109,423)
201,166
(221,748)
40,074
(44,174)
36,808
(40,574)
226,460
(249,629)
404,573
(445,966)
61,620
(67,925)
55,499
(61,177)
1,143,027
(1,259,972)
748,405
(824,975)
216,493
(238,643)
348,351
(383,991)
546,214
(602,098)
380,551
(419,486)
49,155
(54,184)
494,921
(545,557)
96,160
(105,998)
705,921
(778,145)
266,230
(293,468)
168,355
(185,580)
"C, %
IMb
0.008
0.006
0.04
0.006
0.01
0.005
0.01
0.05
0.04
0.003
0.04
0.04
0.04
0.2
0.03
0.02
0.03
0.004
0.004
0.003
0.01
0.09
0.03
mass from mixing plants; Mfa a mass, state burden.
167
-------
MASS OF PARTICULATE EMISSIONS FROM FERTILIZER MIXING PLANTS (continued)
State
Missouri
Nebraska
Nevada
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Total
Number of plants
Ammon. —
gran.
10
8
0
0
0
3
5
2
13
3
2
3
0
5
5
3
7
0
4
3
0
7
0
195
Bulk
blend
390
100
1
9
10
35
21
86
260
133
69
52
3
21
178
74
167
15
94
55
3
232
20
5,640
Liquid
mix
150
50
1
3
8
5
60
53
102
29
35
9
0
85
122
44
387
0
30
100
0
50
10
2,768
State
production,
metric
tons/yr
(tons/yr)
1,170,700
(1,290,454)
574,460
(633,223)
2,840
(3,130)
15,420
(16,997)
25,020
(27,579)
189,310
(208,675!
359,900
(396,715)
282,210
(311,078)
1,080,690
(1,191,237)
342,570
(377,612)
232,240
(255,997)
215,620
(273,676)
3,450
(3,803)
402,150
(443,287)
645,230
(711,232)
300,070
(330,765)
1,174,170
(1,294,279)
17,250
(19,015)
346,280
(381,702)
372,860
(411,000)
3,450
(3,803)
679,390
(748,888)
39,900
(43,982)
20,260,000
(22,390,000)
Controlled
particulate
emissions
metric
tons/yr
(tons/yr)
243
(268)
117
(129)
1
(1)
4
(4)
4
(5)
42
(46)
60
(66)
53
(59)
224
(247)
77
(85)
46
(50)
48
(53)
1
(1)
62
(68)
118
(130)
58
(64)
152
(167)
5
(6)
74
(82)
55
(61)
1
(1)
152
(167)
7
(8)
4,209
(4,441)
Total state
particulate
emissions, 53
metric
tons/yr
(tons/yr)
202,438
(223,146)
95,339
(105,092)
94,041
(103,661)
151,771
(167,296)
102,787
(113,301)
160,046
(176,418)
481,026
(530,231)
78,979
(87,058)
1,766,085
(1,946,743)
93,597
(103,171)
169,451
(186,785)
1,810,629
(1,995,843)
13,073
(14,410)
198,770
(219,103)
52,337
(57,691)
409,711
(451,621)
549,408
(605,609)
71,693
(79,027)
477,502
(526,347)
161,937
(178,502)
213,718
(235,580)
411,565
(453,665)
75,428
(83,144)
16,430,000
(18,110,000)
EMp3. %
EMb
0.1
0.1
0.001
0.003
0.004
0.03
0.01
0.07
0.01
0.08
0.03
0.003
0.008
0.03
0.2
0.01
0.03
0.007
0.02
0.03
0.001
0.04
0.009
aM = mass from mixing plants;
mass, state burden.
168
-------
APPENDIX H
CAPITAL AND OPERATING COST FOR HIGH EFFICIENCY WET SCRUBBERS
169
-------
Table H-l. ESTIMATED CAPITAL COST DATA
(COST IN DOLLARS) FOR TWO-STAGE CYCLONIC SCRUBBER56
Conditions/cost
Operating conditions
Effluent gas flow
ACHMb
°C
SCMMC
Moisture content, vol. %
Effluent dust loading
g/SCMd
Particulate, kg/hr
Cleaned gas flow
ACMM
"C
SCMM
Moisture content, vol. %
Cleaned gas dust loading
g/SCM
Particulate, kg/hr
Cleaning efficiency, »
Estimated capital costs
Gas cleaning device cost
Auxiliaries cost
Fan(s)
Pumps
Damper (s)
Conditioning equipment
Dust disposal equipment
Installation cost
Engineering
Foundations and support
Ductwork
Stack
Electrical
Piping
Insulation
Painting
Supervision
Startup
Performance test
Other
Total cost
Medium efficiency
scrubber
560 DSCMM3
1,000
82
870
35
18
60
1,000
73
880
36
0.35
1.2
98
S 48,9006
14,050e
91,7006
$154,6506
840 DSCMM8
1,600
82
1,300
35
18
90
1,500
73
1,300
36
0.35
1.8
98
S 66,400
21,767
17,350f
3,850f
l,450f
0
0
102,417
6,750f
19,300f
23,500f
4,400f
9,250f
5,750f
^,150f
ll,500f
$190,584
High
efficiency
scrubber
1,344 DSCMM9
2,500
* 82
^,100
35
18
140
2,400
73
2,100
36
0.35
2.9
98
$ 92,867
33,900
30,400f
5,800f
2,150f
0
0
145,733
10,500f
25,000f
33,750f
8,000f
15,350f
9,250f
2,150f
17,000f
$272,500
= Dry standard cubic meter/minute.
Actual cubic meter/minute.
Standard cubic meter/minute.
DSCMM
bACMM =
CSCMM =
SCM = Standard cubic meter.
eOnly two bids obtained for this size.
Auxiliaries and items of installed cost averaged from two bids;
third bidder did not itemize.
NOTE: Blanks indicate that data were not reported in reference cited.
170
-------
Table H-2. ANNUAL OPERATING COST DATA FOR TWO-STAGE CYCLONIC SCRUBBERS56
Operating cost item
Operating factor, hr/yr
Total operating labor
Total maintenance
Total replacement parts
Utilities
Electric power
Fuel
Pond water (make-up)
Water (cooling)
Chemicals
Total utilities
Total direct cost
Annualized capital charges
Total annual cost
Unit cost
$0.003/MJ
($0.001/kw-hr)
$0.07/1,000 liter
($0.25/1,000 gal)
$0.01/1,000 liter
($0.05/1,000 gal)
Annual operating costs, $/yr
Moderate efficiency
scrubber
560 DSCMM3
8,000
3,670b
6,825b
4,229b
12,030b
2,235b
14,265
28,989
15,465
44,454
850 DSCMM3
8,000
2,447
6,033
3,801
15,814
5,259
0
0
21,073
33,354
19,058
52,412
High efficiency
scrubber
1,400 DSCMM3
8,000
2,447
7,450
5,355
24,920
8,433
0
0
33,353
48,605
27,205
75,810
DSCMM = Dry standard cubic meter per minute.
Only two bids obtained for this size.
NOTE: Blanks indicate that data were not reported in reference cited.
-------
Table H-3.
ESTIMATED CAPITAL COST DATA (COSTS IN DOLLARS)
FOR VENTURI CYCLONIC SCRUBBERS56
Conditions/cost
Operating conditions
Effluent gas flow
ACMMb
°C
SCMMC
Moisture content, vol. %
Effluent dust loading
g/SCMd
Particulate, kg/hr
Cleaned gas flow
ACMM
«c
SCMM
Moisture content, vol. %
Cleaned gas dust loading
g/SCM
Particulate, kg/hr
Cleaning efficiency, %
Estimated capital costs
Gas cleaning device cost
Auxiliaries cost
Fan(s)
Purap(s)
Damper (s)
Conditioning equipment
Dust disposal equipment
Installation cost
Engineering
Foundations and support
Ductwork
Stack
Electrical
Piping
Insulation
Painting
Supervision
Startup
Performance test
Other
Total cost
Medium efficiency
scrubber
560 DSCMM8
1,000
82
870
35
18
60
1,000
73
880
36
0.35
1.2
98
$ 33,250e
18,0256
76,680e
$127,9556
850 DSCMM3
1,600
82
1,300
35
18
90
1,500
73
1,300
36
0.35
1.8
98
$ 44,433
28,500
24,000f
J,800f
*,450f
0
0
88,833
6,600f
15,000f
0
13,300f
5,300f
5,800f
*,ioof
4,500f
2,150f
14,750f
$161,766
High
efficiency
scrubber
1,400 DSCMM3
2,500
82
2,100
35
18
140
2,400
73
2,100
36
0.35
2.9
98
$ 61,467
45,300
43,100f
6,700f
3,150f
0
0
128,577
8,500f
21,700f
0
29,750f
o,750f
B,600
2,815f
6,250f
2,150f
21,600f
$235,344
dDSCMM = Dry standard cubic meter/fainute.
ACMM = Actual cubic meter /biinute.
CSCMM = Standard cubic meter Aiinute.
SCM = Standard cubic meter.
eOnly two bids obtained for this size.
Auxiliaries and items of installed cost averaged from two
bids. Third bidder did not itemize.
NOTE: Blanks indicate that data were not reported in reference cited.
172
-------
Table H-4. ANNUAL OPERATING COST DATA FOR VENTURI CYCLONIC SCRUBBERS56
U)
Operating cost item
Operating factor, hr/yr
Total operating labor
Total maintenance
Total replacement parts
Utilities
Electric power
Fuel
Pond water (make-up)
Water (cooling)
Chemicals
Total utilities
Total direct cost
Annual! zed capital charges
Total annual cost
Unit cost
$0.003/MJ
($0.011/kw-hr)
$0.07/1,000 liter
($0.25/1,000 gal)
$0.01/1,000 liter
($0.05/1,000 gal)
Annual operating costs, $/yr
Moderate efficiency
scrubber
560 DSCMM9
8,000
2,925b
4,650b
3,932b
17,850b
1,425C
18,808b
30,315b
12,795b
43,110b
850 DSCMM9
8,000
1,950
4,100
3,511
27,645
5,562d
0
0
31,354
40,915
16,177
57,092
High efficiency
scrubber
1,400 DSCMM3
8,000
1,950
5,166
4,828
43,901
8,950d
0
0
49,868
61,812
23,534
85,346
DSCMM = Dry standard cubic meter per minute.
Only two bids obtained for this size.
°From one bidder only.
Average of two bidders; third bidder did not itemize.
NOTE: Blanks indicate that data were not reported in reference cited.
-------
Table H-5. ESTIMATED CAPITAL COST DATA (COSTS IN DOLLARS) FOR
PACKED CROSSFLOW SCRUBBERS FOR DAP PROCESS PLANTS56
Conditions/cost
Operating conditions
Effluent gas flow
ACMM3
°C
SCMMb
Moisture content, vol. %
Contaminant effluent loading
Fluorine, ppm
kg/hr
Cleaned gas flow
ACMM
ec
SCMM
Moisture content, vol. %
Medium efficiency
scrubber
Small
1,500
73
1,300
36
15
0.95
950
210
900
7
Contaminant cleaned gas loading
Fluorine, ppm
kg/hr
Cleaning efficiency, %
Estimated capital costs
Gas cleaning device cost
Auxiliaries cost
Fan(s)
Pump ( s )
Damper (s)
Installation cost
Engineering
Foundations & support
Ductwork
Stack0
Electrical0
Piping
Insulation
Painting
Supervision
Startup
Performance test
Other
Total cost
4.1
0.19
80
$27,425
13,684
6,425
7,089
170
38,462
2,000
3,500
5,000
5,500
5,430
10,550
375
375
450
710
1,475
1,500
$79,471
Large
2,400
73
2,100
36
15
1.5
1,500
210
1,400
7
4.1
0.30
80
$ 43,200
17,470
9,400
7,755
315
50,358
2,000
5,000
6,200
6,000
7,970
15,200
500
450
450
710
1,475
2,000
$111,028
High efficiency
scrubber
Small
1,500
73
1,300
36
15
0.95
950
210
900
7
3.25
0.14
85
$32,375
13,684
6,425
7,089
170
38,962
2,000
3,500
5,000
5,500
5,430
10,550
375
375
450
710
1,475
1,500
$85,021
Large
2,400
73
2,100
36
15
1.5
1,500
210
1,400
7
3.25
0.23
85
$ 47,050
17,470
9,400
7,755
315
50,857
2,000
5,000
6,200
6,000
7,970
15,200
500
450
450
710
1,475
2,000
$115,377
ACMM ^ Actual cubic meter/ninute.
SCMM = standard cubic meter/minute.
LItems of installed cost; itemized for materials and labor by one bidder only.
174
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Table H-6. ANNUAL OPERATING COST DATA FOR PACKED CROSSFLOW SCRUBBERS56
Operating cost item
Operating factor, hr/yr
Total operating labor
Total maintenance
Total replacement parts
Utilities
Electric power
Fuel
Pond water (make-up)
Water (cooling)
Chemicals
Total utilities
Total direct cost
Annualized capital charges
Total annual cost
Unit cost
$0.003/MJ
($0.011/kw-hr)
$0.07/1,000 liter
($0.25/1,000 gal)
$0.01/1,000 liter
($0.05/1,000 gal)
Annual operating costs, $/yr
Moderate efficiency
scrubber
850 DSCMM3
8,000
1,738
1,875
200
4,787
34
4,821
8,624
7,957
16,581
1,400 DSCMM3
8,000
3,613
2,888
250
7,150
55
7,205
13,955
11,103
25,058
High efficiency
scrubber
850 DSCMM3
8,000
1,738
1,875
200
4,990
35
5,025
8,828
8,502
17,330
1,400 DSCMM3
8,000
3,613
2,888
250
7,287
57
7,344
14,095
11,538
25,633
Ul
DSCMM = Dry standard cubic meter per minute.
NOTE: Blanks indicate that data were not reported in reference cited.
-------
SECTION VIII
GLOSSARY OF TERMS
AFFECTED POPULATION - The number of people around a typical
mixing plant who are exposed to a source severity greater
than 0.1 or 1.0, as specified.
AMMONIATOR-GRANULATOR - An apparatus in which ammonia or
its solutions are mixed with other fertilizer materials to
produce a granular mixed fertilizer.
BULK BLENDING - The physical mixing, without chemical
reaction, of granular single nutrient and multinutrient
materials to produce a dry fertilizer mixture.
EMISSION FACTOR - The quantity of a species that is emitted
per unit weight of final product.
FUGITIVE EMISSIONS - Gaseous and particulate emissions
that result from industrial related operations, but which
are not emitted through a primary exhaust system, such as
a stack, flue, or control system.
HAZARD FACTOR - A value equal to the primary ambient air
quality standard in the case of criteria pollutants or to
a reduced TLV (i.e., TLV-8/24-1/100) for noncriteria
pollutants.
177
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LIQUID MIXING - The physical and chemical mixing of liquid
raw materials to produce a fluid mixed fertilizer.
MIXED FERTILIZER - A fertilizer which contains more than one
of the three primary plant nutrients.
N-P-K - A designation which indicates that the mixed ferti-
lizer contains all three primary plant nutrients where N
represents total nitrogen, P represents soluble PaOs, and
K represents soluble K20.
PIPE REACTOR PLANT - A liquid mix plant in which phosphoric
acid and ammonia are combined in a water-jacketed pipe
prior to being mixed with the remaining ingredients.
PUGMILL - A U-shaped trough in which paddles mounted on
twin contrarotating shafts agitate, shear, and knead a
solid-liquid mixture to produce a granular mixed fertilizer.
REPRESENTATIVE PLANT - A plant defined for the purpose of
establishing a base on which to determine the emissions and
severity of a source. Characteristics of the representative
plant are determined by dividing the total annual production
of mixed fertilizers by the number of corresponding mixing
plants.
SOURCE SEVERITY - The ratio of the ground level concentration
of each emission species to its corresponding ambient air
quality standard (for criteria pollutants) or to a reduced
TLV (for noncriteria emission species).
178
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SECTION IX
CONVERSION FACTORS AND METRIC PREFIXES63
To convert from
degree Celsius (°C)
gram/kilogram (g/kg)
kilogram (kg)
meter (m)
meter (m)
meter2 (m2)
meter3 (m3)
metric ton
pascal (Pa)
radian (rad)
second (s)
CONVERSION FACTORS
to
degree Fahrenheit (°F)
pound/ton
pound-mass (Ib mass
avoirdupois)
foot
inch
mile2
foot3
ton (short, 2,000 Ib mass)
inch of water (60°F)
degree (°)
minute
Multiply by
? = 1.8 t + 32
2.000
2.205
3.281
3.937 x 101
3.861 x 10~7
3.531 x 101
1.102
4.019 x 10~3
5.730 x 101
1.667 x 10~2
PREFIXES
Multiplication
Example
= 1 x 10* m
= 1 x 10~3 m
= 1 x 10~6 m
63Metric Practices Guide. American Society for Testing and
Materials. Philadelphia. ASTM Designation: E380-74.
November 1974. 34 p.
Prefix
kilo
milli
micro
Symbol
k
m
V
Factor
103
10- 3
10~6
1 km
1 mm
1 ym
179
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SECTION X
REFERENCES
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Reporting Service, U.S. Department of Agriculture.
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2. Farm Chemicals Handbook - 1973, Dictionary of Plant
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1973. 64 p.
3. Private communications. N. L. Hargett. National
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Alabama.
4. Private communications. Dr. W. C. White. The
Fertilizer Institute, Washington, D.C.
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for Blending Materials. In: TVA Fertilizer Bulk
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1973. p. 9-21.
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Bulletin Y-78. August 1974. p. 46-54.
8. Feed and Weed. Special Report. Farm Chemicals,
1974. 31 p.
9. Private communications. H. L. Balay. National Ferti-
lizer Development Center, TVA, Muscle Shoals, Alabama.
181
-------
10. Farm Chemicals Handbook - 1973, Pesticide Dictionary.
Willoughby, Ohio, Meister Publishing Co., 1973. 191 p.
11. Farmers' Use of Pesticides in 1971. U.S. Department
of Agriculture. Washington. Agriculture Economic
Report No. 252. July 1974. 56 p.
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424 p.
13. Shreve, R. N. Chemical Process Industries, 3rd Edition.
New York, McGraw-Hill Book Co., 1967. 905 p.
14. Achorn, F. P., and H. L. Balay. Phosphoric Acid:
Shipment, Storage, and Use in Fertilizers. Fertili-
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1973.
15. Slack, A. V. Fertilizer Developments and Trends -
1968. Park Ridge, New Jersey, Noyes Development Corp.,
1968. 405 p.
16. Private communications. E. A. Harre. National
Fertilizer Development Center, TVA, Muscle Shoals,
Alabama.
17. Powell, T. E. Granulation in the Fertilizer Industry.
Process Technology International, 18^:271-278, June-
July 1973.
18. Private communications. J. C. Barber. National
Fertilizer Development Center, TVA, Muscle Shoals,
Alabama.
19. Achorn, F. P., and J. S. Lewis, Jr. Equipment to
Control Pollution from Fertilizer Plants. Agricultural
Chemicals and Commercial Fertilizer. 27, February 1972.
20. Robinson, J. M., et al. Engineering and Cost Effective-
ness Study of Fluoride Emissions Control, Vol. I. U.S.
Environmental Protection Agency, Office of Air Programs,
Washington. PB 207506. January 1972.
21. National' Emissions Inventory of Sources and Emissions
of Phosphorus. U.S. Environmental Protection Agency.
Washington. Publication No. EPA-450/3-74/013.
May 1973. 54 p.
22. Private communications. F. P. Achorn. National Ferti-
lizer Development Center, TVA, Muscle Shoals, Alabama.
182
-------
23. Achorn, F. P., and J. C. Barber. Bulk Blender Equip-
ment. Fertilizer Progress. 3^(6) , November-December
1972.
24. Achorn, F. P., and H. L. Balay. Plant Experiences in
Adding Pesticides, Mirco and Secondary Nutrients to
Bulk Blends. In: TVA Fertilizer Conference. Tennessee
Valley Authority. Muscle Shoals, Alabama. Bulletin
Y-62. August 1973. p. 70-79.
25. Achorn, F. P., and W. C. Brummitt. Different Methods
of Adding Pesticides to Bulk Blends. Fertilizer
Progress. 4_:9-10, March-April 1973.
26. Achorn, F. P., and H. L. Balay. Systems for Controlling
Dust in Fertilizer Plants. In: TVA Fertilizer
Conference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-78. August 1974. p. 55-62.
27. Barber, J. C. Environmental Control in Bulk Blending
Plants. 1. Control of Air Emissions. In: TVA
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Muscle Shoals, Alabama. Bulletin Y-62. August 1973.
p. 39-46.
28. Liquid Fertilizer Manual. Peoria, Illinois. National
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29. Achorn, F. P., and J. S. Lewis, Jr. Alternative
Sources of Materials for the Fluid Fertilizer Industry.
Fertilizer Solutions Magazine. lj[(4) : 8-13, July-
August 1974.
30. Private communications. D. K. Murry. National
Fertilizer Solutions Association, Peoria, Illinois.
31. Meline, R. S. Use of a Pipe Reactor in Production of
Liquid Fertilizer of High Polyphosphate Content.
Summary Report. National Fertilizer Development Center,
TVA. Muscle Shoals, Alabama. November 1974. p. 9-11.
32. Achorn, F. P., and H. L. Kimbrough. Latest Develop-
ments in Commercial Use of the Pipe Reactor Process.
Fertilizer Solutions Magazine. _18_(4) , July-August 1974.
33. Killough, B. Liquid Mixing Seminar Is Success.
Fertilizer Solutions Magazine. 3JM5), September-
October 1974.
183
-------
34. Achorn, F. P., H. L. Balay, and H. L. Kimbrough.
Commercial Uses of the Pipe Reactor Process for Pro-
duction of High-Polyphosphate Liquids. Fertilizer
Solutions Magazine. 3/7(2), March-April 1973.
35. Meline, R. S., R. G. Lee, and W. C. Scott. Use of a
Pipe Reactor in Production of Liquid Fertilizers with
Very High Polyphosphate Content. Fertilizer Solutions
Magazine. 1J5 (2) , March-April 1972.
36. Achorn, F. P., and J. I. Bucy. High-Analysis 12-44-0
Produced by Kugler Oil. Fertilizer Solutions Magazine.
16^(5), September-October 1972.
37. Achorn, F. P., and H. L. Balay. Fluid Fertilizer
Mixtures - 1972. In: Phosphorus in Agriculture.
International Superphosphate and Compound Manufacturers'
Assoc., LTD., London, England. Publication No. 60.
December 1972. p. 27-36.
38. Tinsman, W. S. Mixing Techniques - Part 2 - Cold Mix
and Satellites. Fertilizer Solutions Magazine. Il_(3) ,
May-June 1973.
39. Forbes, M. R. Mixing Techniques of Micronutrient with
Liquid and Suspensions. Fertilizer Solutions Magazine.
IT_(5) , September-October 1973.
40. Volk, W. Applied Statistics for Engineers, 2nd Edition.
New York, McGraw-Hill Book Co., 1969. 415 p.
41. Private communications. Jim Price. Texas Air Control
Board, Austin.
42. Private communications. Ray Beckett. Illinois EPA,
Springfield.
43. Private communication. Allen Leevin. Ohio EPA,
Dayton. September 12, 1974.
44. Private communications. Robert lacampo. Florida EPA,
Tallahassee.
45. Private communication. John Pruessner. Indiana Air
Pollution Control Board, Indianapolis. September
19, 1974.
46. Compilation of Air Pollutant Emission Factors. U.S.
Environmental Protection Agency. Washington. Publi-
cation No. AP-42. February 1972. p. 6.10.
184
-------
47. Sax, N. I. Dangerous Properties of Industrial Materials.
3rd Edition. New York, Reinhold Book Corp., 1968.
1251 p.
48. TLV's® Threshold Limit Values for Chemical Substances
and Physical Agents in the Workroom Environment with
Intended Changes for 1975. American Conference of
Governmental Industrial Hygienists. Cincinnati. 1975.
97 p.
49. Particulate Pollutant System Study, Vol. Ill - Handbook
of Emission Properties. U.S. Environmental Protection
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50. McNesby, J. R., and H. Okabe. Vacuum Ultraviolet
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Noyes, W. A., Jr. (ed.). New York, John Wiley and
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51. Cvetanovic, R. J. Addition of Atoms to Olefins in the
Gas Phase. In: Advances in Photochemistry, Vol. 1,
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Publishers, 1963. p. 115-182.
52. Turner, D. B. Workbook of Atmospheric Dispersion
Estimates. U.S. Department of Health, Education, and
Welfare. Cincinnati. Public Health Service. Publi-
cation No. 999-AP-26. 1969. 62 p.
53. National Emission Report - 1972. U.S. Environmental
Protection Agency. Washington. Publication No.
EPA-450/2-74/012. June 1974. 422 p.
54. Towards Cleaner Air - A Review of Britain's Achieve-
ments. Central Office of Information for the British
Overseas Trade Board. London. April 1973. 59 p.
55. Achorn, F. P., H. L. Balay, E. D. Myers, and R. D. Grisso.
A Pollution Solution for Granulation Plants. Farm
Chemicals. 134, August 1971.
56. Air Pollution Control Technology and Costs in Seven
Selected Areas, Phase I (Phosphate Industry). Pre-
pared by Industrial Gas Cleaning Institute, Washington,
for the U.S. Environmental Protection Agency. March
1973. 200 p.
57. Trayer, D. M. Environmental Control in Bulk Blending
Plants. 1. Industrial Hygiene Aspects. In: TVA
Fertilizer Conference. Tennessee Valley Authority.
Muscle Shoals, Alabama. Bulletin Y-62. August 1973.
p. 47-58.
185
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58. Wheeler, E. M. Marketing Trends. In: TVA Fertilizer
Conference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-78. August 1974. p. 88-91.
59. Koepke, W. E. Future Potash Supply. In: TVA Fertilizer
Conference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-78. August 1974. p. 27-34.
60. Nilsen, J. M. Fertilizer Outlook "Iffy." Chemical
Engineering. 82^(6) : 28-29 , March 1975.
61. Nelson, L. B. Trends in Technology. In: TVA Fertilizer
Conference. Tennessee Valley Authority. Muscle Shoals,
Alabama. Bulletin Y-78. August 1974. p. 92-95.
62. Boughner, R. T., and J. L. Nevins. Some Management
Trends in the 1980"s. In: TVA Fertilizer Conference.
Tennessee Valley Authority. Muscle Shoals, Alabama.
Bulletin Y-78. August 1974. p. 82-87.
63. Metric Practices Guide. American Society for Testing
and Materials. Philadelphia. ASTM Designation:
E380-74. November 1974. 34 p.
186
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TECHNICAL REPORT DATA
(Please read Jmtivctions on the reverse before completing)
1. REPORT NO.
EPA-600/2-76-032c
2.
3. RECIPIENT'S ACCESSIOr*NO.
4. TITLE AND SUBTITLE
Source Assessment: Fertilizer Mixing Plants
5. REPORT DATE
March 1976
6. PERFORMING ORGANIZATION CODE
7. AUTHOHiS)
Gary D. Rawlings and Richard B. Reznik
8. PERFORMING ORGANIZATION REPORT NO.
MRC-DA-511
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Monsanto Research Corporation
Dayton Laboratory
Dayton, Ohio 45407
10. PROGRAM ELEMENT NO.
1AB015; ROAP 21AXM-071
11. CONTRACT/GRANT NO.
68-02-1874
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final; 1-12/75
14. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES EPA-650/2-75-019a was the first report of this series. EPA
project officer for this report is D.A.Denny, Mail Drop 62, Ext 2547.
is. ABSTRACT The report des cribes a study of air pollutants emitted by the mixed ferti-
lizer industry, consisting of three types of mixing plants: ammoniation/granulation
(A/G) (195 plants), bulk blend (5,640 plants), and liquid mix (2,768 plants). The poten-
tial environmental effect of this source was evaluated, using source severity (defined
as the ratio of the maximum ground-level concentration of an emission to the ambient
air quality standard for criteria pollutants or to a modified TLV for non-criteria
pollutants). Source severity factors for particulate emissions from A/G, bulk blend,
and liquid mix plants are 0.1, 0.14, and 0.01, respectively. Severity factors for
ammonia from A/G and liquid mix plants are 0.26 and 0.01, respectively. A/G plants
(excluding diammonium phosphate plants) produced 45% of all mixed fertilizers in
1973; bulk blend and liquid mix plants produced 32% and 23%, respectively. Primary
emissions from A/G plants are NH3 and particulates. Only particulates are emitted
from bulk blend plants. Primary emissions from liquid mix plants are NH3 and
particulates. Each of the emission values (for each pollutant from each source) is
less than 0.1% of the corresponding national emissions of that material from all
stationary sources.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air Pollution
Fertilizers
Agricultural Engineering
Assessments
Dust
Ammonia
b.IDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control
Stationary Sources
Fertilizer Mixing Plants
Source Severity
Particulate
c. COSATI Field/Group
13B
02A
02C
14B
11G
07B
13. DISTRIBUTION STATEMENT
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
201
Unlimited
20. SECURITY CLASS (Tills page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
187
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