United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/3-80-018
May 1980
Air
Source Category
Survey: Thermal Process
Phosphoric Acid
Manufacturing Industry
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EPA-450/3-80-018
Source Category Survey:
Thermal Process Phosphoric Acid
Manufacturing Industry
Emission Standards and Engineering Division
Contract No. 68-02-3059
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air, Noise, and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
May 1980
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This report has been reviewed by the Emission Standards and Engineering
Division, Office of Air Quality Planning and Standards, Office of Air, Noise,
and Radiation, Environmental Protection Agency, and approved for publica-
tion . Mention of company or product names does not constitute endorsement
by EPA. Copies are available free of charge to Federal employees, current
contractors and grantees, and non-profit organizations - as supplies permit
from the Library Services Office, MD-35, Environmental Protection Agency,
Research Triangle Park, NC 27711; or may be obtained, for a fee, from the
National Technical Information Service, 5285 Port Royal Road, Springfield,
VA 22161.
Publication No. EPA-450/3-80-018
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Section
1.0
2.0
3.0
3.1
3.2
4.0
4.1
4.2
4.3
5.0
5.1
5.2
6.0
6.1
6.2
6.3
7.0
7.1
7.2
8.0
9.0
CONTENTS
Title
Preface
SUMMARY
INTRODUCTION
CONCLUSIONS AND RECOMMENDATIONS
Conclusions
Recommendations
INDUSTRY DESCRIPTION
Source Category
Industry Production
Process Description
AIR EMISSIONS
Plant and Process Emissions
Total National Emissions
EMISSION CONTROL SYSTEMS
Control Approaches
Alternative Control Techniques
"Best Systems" of Emission Reduction
EMISSION DATA
Availability of Data
Sample Collection and Analysis
STATE AND LOCAL EMISSION REGULATIONS
REFERENCES
Page
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. . . . 15
. . . . 21
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iii
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LIST OF TABLES
No. Title Page
4-1 Thermal Process Phosphoric Acid Manufacturers, 1980 ... 9
4-2 Number of Thermal Process Phosphoric Acid Plants,
1968 to 1980 10
4-3 Grades of Phosphoric Acid 12
4-4 Major Phosphoric Acid Products and Their Uses 13
4-5 Typical Stack Effluent Characteristics 19
5-1 Particulate Emissions From a Typical Thermal Process
Phosphoric Acid Plant 22
6-1 Summary of Control Equipment Applied to Operational
Plants 25
8-1 Summary of State Air Pollution Regulations 32
LIST OF FIGURES
No. Title Page
4-1 Historical Production of Thermal Process Phosphoric
Acid 14
4-2 Production of Phosphoric Acid (Total, Wet Process, and
Thermal Process) 16
4-3 Flow Diagram for Typical Thermal Process Phosphoric Acid
Plant 17
iv
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1.0 SUMMARY
This Source Category Survey Report presents information gathered on
processes, pollutants and control equipment for the thermal process
phosphoric acid manufacturing industry. This industry manufactures
phosphoric acid from elemental phosphorus, water, and air. This source
category is a subpart of Standard Industrial Classification (SIC) code 2874.
There are 20 plants in the United States which produce thermal
process phosphoric acid. These plants are located in 14 states rather
evenly distributed across the country. In 1978, 627,300 Mg (691,500 tons)
of 100 percent P205 were produced; there were 23 plants operational that
year. Thus, average plant production is 27,300 Mg (30,100 tons) of
100 percent P20g per year.
Nearly 50 percent of all thermal process acid is used in detergent
manufacturing. Although this market has now stabilized, it had been
decreasing at the rate of 10 percent per year since 1970 due to the
reduction of phosphates in detergents. Thermal process phosphoric acid
is also used in beverages, food, dentrifices, metal treating, and fire
control.
The major components of thermal process phosphoric acid production
are: (1) combustion of elemental phosphorus with oxygen to produce
phosphorus pentoxide and (2) hydration of the phosphorus pentoxide fume
to produce the product acid. The production of elemental phosphorus was
not considered in this report because it is not produced at the same
location as the acid and because it is used for products in addition to
phosphoric acid. The purification of thermal process acid, as required
to meet food grade specifications, was overviewed.
The main pollutant from the thermal process is particulate, in the
form of acid mist. Typical State Implementation Plan (SIP) particulate
regulations for new plants are expressed by the equation:
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E = 4.1 p°'67
where E = allowable particulate emissions, in Ib/h, and
p = process weight rate, in tons/h.
Typical plant emissions were calculated to be 2.6 kg/h (5.73 Ib/h).
Other pollutants emitted include: nitrogen oxides from the combustion
chamber, hydrogen sulfide from acid purification, and trace metals (speci-
fically arsenic) as constituents of the phosphoric acid. These emissions
are estimated to be minor; the arsenic emissions, for example, have been
calculated to be less than 0.1 g/h (0.002 Ib/h).
The recommended method for sampling phosphoric acid mist is a slightly
modified version of EPA Reference Method 5. This method, as well as
suggested analysis methods, are described in detail in Section 7.2.
Technology is available for control of acid mist. The equipment
used extensively by the industry (to recover phosphoric acid and to
control air pollution) includes: packed towers, scrubbers, fiber mist
eliminators, and wire mesh contactors. All plants use a combination of
control equipment, with typical recovery efficiency estimated to be over
99 percent. The best available control technology (BACT) is a packed
tower or scrubber with some form of fiber mist eliminator or wire mesh
contactor.
The information gathered in this survey indicates that a New Source
Performance Standard (NbPS) should not be developed for the thermal
process phosphoric acid industry. The main reasons for this recommendation
are: (1) no increase in capacity at existing plants or construction of
new plants is anticipated in the next 5 years, and (2) BACT will be
utilized (for the purpose of product recovery) even if an NSPS 1s not
developed. Even if a plant is built in the next 10 years, the air quality
impact will be negligible.
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2.0 INTRODUCTION
The authority to promulgate standards of performance for new sources
is derived from Section 111 of the Clean Air Act. Under the Act, the
Administrator of the U.S. Environmental Protection Agency is directed to
establish standards relating to the emission of air pollutants and is
accorded the following powers:
1. Identify those categories of stationary emission sources that
contribute significantly to air pollution and which could be reasonably
anticipated to endanger the public health and welfare;
2. Distinguish among classes, types, and sizes within categories of
new sources for the purpose of establishing standards; and
3. Establish standards of performance for stationary sources which
reflect the degree of emission reduction achievable through application
of the best system of continuous emission reduction, taking into consid-
eration the cost, energy, and environmental impacts associated with such
emission reduction.
The term "stationary source" means any building, structure, facility,
or installation which emits or may emit any air pollutants. A source is
considered new if its construction, reconstruction, or modification is
commenced after publication of the proposed regulations. Modifications
subjecting an existing source to New Source Performance Standards (NSPS)
are defined in 40 CFR Part 60.14.1 Modifications include any physical
change in the source or change in methods of operation which results in
an increase in the amount or change in type of air pollutants emitted.
Reconstructions subjecting an existing source to these standards are
defined in 40 CFR Part 60.15 as "replacement of components of an existing
facility to such an extent that the the fixed capital cost of the new
components exceeds 50 percent of the fixed capital cost that would be
required to construct a comparable entirely new facility . . . ."^
Thermal process phosphoric acid manufacturing was recently included
on a priority list of major source categories for which new source
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standards should be developed. This source category survey was performed
to determine if development of an NSPS for the thermal process phosphoric
acid manufacturing industry is justified and to identify what processes and
pollutants, if any, should be subject to regulation. Information about
processes, air pollutants, and control equipment was gathered as follows:
1. Process and emission data were collected from literature searches
and contacts with state and local air pollution control agencies.
2. Two thermal process phosphoric acid plants were visited to
develop an understanding of manufacturing processes and to collect data
on operating air pollution control equipment.
3. Representatives of industry, government agencies, trade
associations, and control equipment vendors were contacted to gather
information on thermal process phosphoric acid production and projected
industry expansion.
Phosphoric acid is manufactured by two distinct processes: (1) the
thermal process and (2) the wet process. The thermal process involves
the burning of elemental phosphorus to form phosphorus pentoxide which is
then hydrated. The wet process, on the other hand, consists of the
treatment of phosphorus-containing rock with sulfuric acid.
Thermal process and wet process phosphoric acid differ in their
degree of purity and hence serve different markets. Thermal process acid
is low in impurities and is used primarily es an intermediate in the
production of detergents, water builders, food additives, and animal
feed. It is also used in fertilizer, metal treatment, and dentifrices.
Although thermal process acid could be used for virtually all phosphoric
acid requirements, it is used only when high purity acid is required
because the production of elemental phosphorus is energy intensive and
expensive. Wet process phosphoric acid, which is less expensive to
produce, is used in markets where less purity is acceptable, primarily in
the production of fertilizer. Wet acid impurities include fluorides,
arsenic, calcium, iron, vanadium, aluminum, and sulfates. The thermal
process is a more efficient method for using lower grade rock than the
wet process. Presently, thermal process phosphoric acid comprises less
than 9 percent of the total phosphoric acid produced in the United
States.^ Methods to remove impurities in wet process acid are being
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developed, and It is possible that wet process acid may expand into the
thermal process market at some time in the future. '
Historically, the thermal process production of phosphoric acid has
developed from a one-step process to a two-step process. In the one-step
process, phosphorus-containing rock is treated in an electric or blast
furnace to produce elemental phosphorus vapor. The phosphorus vapor is
passed directly, without cooling, to a combustion chamber where it is
burned to produce phosphorus pentoxide (P^Q)- **• 1S tnen hydrated in
an absorption tower to form phosphoric acid.
All thermal process phosphoric acid is currently produced by a
two-step process. The first step consists of reduction of the phosphorus-
containing rock in an electric furnace to produce liquid elemental phos-
phorus, P*. The second step consists of burning the elemental phosphorus
with air in a combustion chamber at 1700°C to 2800°C.8 The resultant
phosphorus pentoxide is hydrated with water and weak phosphoric acid
until the desired strength of the final phosphoric acid is reached.
Presently, the first and second steps of the two-step process are
performed at two separate locations, because the shipment cost of elemental
Q in
phosphorus is less than that for phosphoric acid. »IU (Four tons of
phosphoric acid correspond by weight to one ton of phosphorus.) The
elemental phosphorus is produced (first step) at the source of the
phosphorus-containing rock. Although phosphorus-containing rock is
primarily mined in Florida, rock from Tennessee and several western
states is particularly suitable for elemental phosphorus production.
Phosphoric acid is produced (second step) from elemental phosphorus at
plants that serve local and regional markets.
The portion of the thermal process phosphoric acid manufacturing
industry considered for the development of an NSPS is only the second
step of the two-step process. Specific details on the air pollutant
emission sources of the second step are documented in Chapter 4.
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3.0 CONCLUSIONS AND RECOMMENDATIONS
3.1 CONCLUSIONS
1. In 197tt, the total national production of thermal process
phosphoric acid was 627,300 Mg (691,500 tons).5 During the period of
1978 to 1985, the national production is expected to increase at an
average annual growth rate of less than 2 percent.
2. No increase in capacity at existing plants or construction of
new plants is anticipated in the next five years.
3. The primary pollutant from the thermal process is particulate in
the form of phosphoric acid mist. Other pollutants emitted in the process
are: nitrogen oxides from the combustion chamber, hydrogen sulfide from
acid purification, and trace metal constituents of the phosphoric acid
mist.
4. The health effects of phosphoric acid mist are much less than
those of other acid mists (e.g., sulfuric acid mist, nitric acid mist).
The Threshold Limit Value (TLV) for noticeable but not uncomfortable
effects of exposure to phosphoric acid is 1 mg/m of air sampled (for an
8-hour time period).
5. Control technology is available for particulate (phosphoric acid
mist) pollution control. There are no uncontrolled plants in the United
States because the major pollutant, phosphoric acid mist, is valuable
enough to justify the cost of a high degree of recovery.
6. Emission data are available for most plants. Based on data
supplied by state regulatory agencies, emissions from plants average
60 percent below state allowable limits.
7. The standard method for evaluating emissions of particulate is a
slightly modified version of EPA Reference Method 5. The major revisions
are: (1) removal of the filter support and filter and (2) use of 250 ml
and 15U ml of deionized water in the first and second impingers in place
of 200 ml distilled water in each impinger. This modified method is
described in detail in EPA Publication No. AP-48.12
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3.2 RECOMMENDATIONS
It is recommended that an NSPS not be developed at this time for the
thermal process phosphoric acid industry. A standard would have no air
quality impact for the following reasons:
1. No facilities are expected to be covered by the standard in the
next five years. Growth of the industry is not likely. The industry is
currently operating at approximately 50 percent of full production capacity.
Existing capacity is sufficient to meet increased demand. No process
changes are anticipated. Equipment life of major components is estimated
to be 15 to 3D years. No plants are currently under construction, and no
company indicated specific plans for new plant construction or expansion
of existing capacity. »
2. Best available control technology (BACT) will be utilized to
recover product even if an NSPS is not promulgated. All existing plants
use some form of control equipment with typical particulate control
efficiency estimated to be over 99 percent. Allowable particulate emis-
sions, under State Implementation Plans (SIP), from a typical plant are
calculated to be 2.6 kg/h (5.73 Ib/h) or 20.6 Mg/yr (22.7 tons/yr). On
the average, actual particulate emissions were calculated to be 60 percent
below SIP regulations. Even if a thermal process plant is built in the
next 10 years (e.g., to serve the need for phosphoric acid in a specific
region), the impact of an NSPS will be negligible.
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4.0 INDUSTRY DESCRIPTION
4.1 SOURCE CATEGORY
The source category considered in this report is the manufacture of
thermal process phosphoric acid from elemental phosphorus. This category
is a subpart of the Standard Industrial Classification (SIC) code 2874.
It is also specified by National Emissions Data System (NEDS) Source
Classification Codes (SCC) 3-01-017-01 and 3-01-017-99, with emission
factors in units of tons of phosphorus burned and tons of phosphoric acid
produced, respectively. An alternative name for the thermal process is
the phosphorus burning process.
There are 20 plants in the United States which currently produce
phosphoric acid from elemental phosphorus (see Table 4-1). These plants
are located in 14 states rather evenly distributed across the country.
The number of phosphoric acid plants has been decreasing in recent years
(see Table 4-2). Since 1968, nine plants have closed; two plants have
opened; and at one plant, capacity has doubled.
In addition to a decrease in the number of thermal phosphoric acid
plants, there has been a decrease in the utilization of capacity. The
industry ran at an average of 64 to 68 percent of capacity in 1975 and
now is running at 50 percent of capacity. Capacity utilization is expected
to deteriorate further to 44 to 49 percent by 1982, assuming there are no
plant closures.15*16'17
Two factors which tend to reduce the growth in this industry are the
increased cost of elemental phosphorus (resulting from increased electrical
power costs) and the reduction of the phosphate content of detergents.
Thermal process phosphoric acid is used as a phosphorus carrier in
markets where high purity acid is required. The largest markets for the
acid are water builders and detergents. Other markets include: foods,
beverages, pet foods, and dentifrices; metal treatment; fire control; and
miscellaneous uses.15'18 The markets of thermal process phosphoric acid
are very well established. Table 4-3 lists the most common grades of
8
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TABLE 4-1. THERMAL PROCESS PHOSPHORIC ACID MANUFACTURERS, 1980
Company
Location
FMC Corporation
Hooker Chemical Company
Hydrite Chemical Company
Mobil Chemical Company
Monsanto Company
Stauffer Chemical Company
Newark, California
Lawrence, Kansas
Carte ret, New Jersey
Jeffersonville, Indiana
Columbia, Tennessee
Miller (Dallas), Texas
Milwaukee, Wisconsin
Fernald, Ohio
Charleston, South Carolina
Long Beach, California
Augusta, Georgia
Trenton, Michigan
Carondolet (St. Louis), Missouri
Kearney, New Jersey
Richmond, California
South Gate, California
Chicago, Illinois
Chicago Heights, Illinois
Morrisville, Pennsylvania
Nashville, Tennessee
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TABLE 4-2 NUMBER OF THERMAL PRXESS PHOSPHORIC ACID PLANTS,
1968 TO 1980a
Date No. of plants
1968 27
1975 26
1978 23
1980 20
aSources: references 12 and 16 and telephone contacts with
industry.
10
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TABLE 4-3. GRADES OF PHOSPHORIC ACID18
Grade Concentration
Technical 50%, 75%, 85%
Food 75%, 80% H3P04
USP (chemical) 10%, 85% H3P04
90% 65% P205
100% acid 72% P20&
105% acid 76% P205
Commercial 54% POc
11
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phosphoric acid produced. All food grade acid is treated for removal of
heavy metals (such as arsenic and lead) in order to meet strict food
19
codes. More than 2UO user-specific phosphate products may be produced
by a single phosphoric acid plant. The most common phosphate compounds
and their corresponding uses are summarized in Table 4-4.
4.2 INDUSTRY PRODUCTION
The national production of thermal process phosphoric acid increased
steadily from 1940 to 1970 (see Figure 4-1 ).5'12 In the past decade,
however, production has been decreasing an average of about 5 percent per
year. As indicated in Figure 4-1, the 1978 production of thermal process
acid was 627,300 Mg (or 691,500 tons) as 100 percent P205.
The decrease in production has been caused mostly by a weakening
market for phosphorus in detergent and water builders; approximately
50 percent of all thermal process acid produced is used in the detergent
15 18
market. ' The use of phosphates in detergents has been declining at
approximately 10 percent per year since 1970 as a result of evidence
that detergent phosphates accelerate undesirable entrophication in water
bodies. Regional legislation requiring reduced phosphates in detergents
has resulted in the development of nonphosphate or reduced-phosphate
detergent products. In 1968 and 1969 the average phosphorus content of
solid home laundry detergents was 13 percent; solid detergent today
20
contains an average of less than 5 percent phosphorus.
Other smaller markets for thermal process phosphoric acid have been
steady or slowly increasing in the past decade, compensating for the
dramatic decline in the detergent market. Food, beverage, pet food, and
dentifrice markets, which presently use 16 percent of the thermal process
phosphoric acid in the United States, are becoming increasingly mature.
Their projected growth rate for the next five years ranges from 1 to
4 percent. Use of acid for treatment of metal surfaces (primarily for
aluminum polishing and phosphatizing), which was growing at a rate of
about 5 percent per year in the 1960's, is expected to decrease by 2 to
4 percent in the 1980's.15
Although production of thermal process phosphoric add has been
decreasing for the past decade, total production of phosphoric acid has
12
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TABLE 4-4. MAJOR PHOSPHORIC ACID PRODUCTS AND THEIR USES4'7'8'18
Product
Uses
Sodium phosphates
Monosodium phosphate (MSP)a
Disodium phosphate (DSP)
Trisodium phosphate (TSP)
Sodium tripolyphosphate (STPP)
Tetrasodium pyrophosphate (TSPP)
Sodium aluminum phosphate
Sodium acid pyrophosphate (SAPP)
Potassium phosphates
Monopotassium phosphate (MKP)
Dipotassium phosphate (DKP)
Tripotassium phosphate (TKP)
Potassium polyphosphates
Calcium phosphates
Monocalcium phosphate
Di calcium phosphate
Tricalcium phosphate
Ammonium phosphates
Fluid
Solid
Direct Acid
Buffer in acid-type cleaners.
Water treatment, dishwasher
detergents, medicine, food
processing, textile dyeing,
ceramic glazes.
Heavy duty detergent, water
softening.
Detergents, clay processing,
elastomers.
Detergent builder.
Baking powders and leavening
agents.
Liquid detergents, dairy products,
elastomers, antifreeze.
Foods, dentifrices, beverages,
including baking powders and
leavening agents.
Fertilizers, livestock feeds,
fire control.
Fire control, foods.
Metal surface treatments, foods,
refractories, beverages, catalysts.
?Made by treating phosphoric acid (orthophosphoric) with soda ash.
U M t -J «•. L... ._ .K 1 ^ £.*..£ L..J ^_ .!_»_ • • . • • .
Made by calcining anhydrous disodium orthophosphate.
13
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1200
•rr>
'• o
O O
•X.
C
O U
O O
13 J3
T3 Q-
O to
J- O
Q- -C
d.
•
CO W
• to
Z3 OJ
U
O
Q.
1000
800
600
400
200 •
Total
Detergent
Food*
Metal *
treating
1940
1945
1950
1955
1960
1965
1970
1975
1980
^Thermal process phosphoric acid production applied to the specific
market.
Figure 4-1. Historical production of thermal process phosphoric add.5'12
14
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been increasing. This increase has been caused by the increase in
production of wet process phosphoric acid (see Figure 4-2), which is used
largely in the production of agricultural fertilizers. Wet process acid
is less expensive to produce because it uses phosphate rock directly
rather than elemental phosphorus, the energy-intensive raw material used
in the thermal process. In 1978, energy accounted for approximately
15
66 percent of the total cost of producing elemental phosphorus. Sharp
increases in the cost of energy have stimulated interest in substituting
wet acid for thermal acid in some products. Historically, however, most
U.S. producers have determined that the high purity acid can be produced
more economically using thermal process acid than purified wet process
acid.
No new thermal process plants are expected to be built in the next
5 years. If a plant were built in 5 to 10 years, it would most likely be
small-to-medium size and would serve the demand for phosphoric acid in a
13 14
specific location. '
4.3 PKOCESS DESCRIPTION
Figure 4-3 presents an overall flow diagram for the production of
thermal process phosphoric acid and subsequent acid purification. The
raw materials for acid production are: elemental phosphorus, air, and
water. Elemental phosphorus is commonly shipped by tank car (as a liquid,
l ?
under water) to the plant from an elemental phosphorus production plant.
Elemental phosphorus is transferred from a storage tank to a combustion
chamber at typical feed rates of 4 to 20 liters/min (1 to 5 gal/min).21
In the combustion chamber, the phosphorus combines with oxygen to form
phosphorus pentoxide (P401Q) by the combustion reaction:
P4 + 502 - P401Q
Combustion takes place at 1650°C to 2760°C (3000°F to 5000°F).7 The
combustion chamber is usually built of water-jacketed stainless steel,
22
brick-level or graphite blocks. The resulting phosphorus pentoxide
23
particles form a dense fume.
15
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to
c
o
en
O
-a
u
u
Q.
in
O
u
3
•o
O
Q.
10,000 •
9.000 .
8.000 •
7.000 .
6.000
5.000
4.000
3.000
2.000.
1.000
Total
Wet process
Thermal process
1960 1965
1970 1975 1980
Figure 4-2. Production of phosphoric acid
(total, wet process, and thermal process).
16
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AIR
ELEMENTAL
PHOSPHORUS
FEED TANK
\
STACK
EFFLUENT
(AIR * H3PO4 MIST)
AGIO PURIFICATION
STACK EFFLUENT
(AIR + H2S)
HYDROGEN SULFIDE,
SODIUM HYDROSULFIDE,
OR SODIUM SULFIDE
PRODUCT
BLOWER
I PUMP
PHOSPHORUS
COMBUSTION
CHAMBER
BURNING AND HYDRATION
ACID TO STORAGE
ACID PURIFICATION
(USED IN THE MANUFACTURE OF ACID
FOR FOOD AND SPECIAL USES)
Figure 4-3. Flow diagram for typical thermal process
phosphoric acid plant.12'21
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The phosphorus pentoxlde passes to the hydrator where it is contacted
with water and/or an aqueous solution of weak phosphoric acid. The
reaction of phosphorus pentoxide and water in the weak acid is:^
This reaction is exothermic and results in orthophosphoric acid, normally
called phosphoric acid. (In some processes, the phosphorus pentoxide
fume may be contacted with alkaline solutions to form salts containing
phosphates.)
The product acid is drained from the bottom of the hydrator to
storage. An acid purification process is used if removal of these heavy
metals such as arsenic is desired.
Acid mist is also formed in the hydrator. The acid mist, unabsorbed
phosphorus pentoxide, and excess air are contacted with water to form
weak acid. This collection process serves to both enhance product recovery
and reduce air pollution emissions. The collection process is accomplished
by industry in a variety of ways; typically, a plant uses several control
devices (see Chapter 6) to agglomerate the particles and to capture the
liquid parti culate.
The yield of the overall process of thermal process phosphoric acid
manufacturing is high. Loss of any form of phosphoric acid, through
leaks in the system or to the stack effluent (in the form of acid mist),
is costly.
Typical stack effluent characterics are summarized in Table 4-5.
Phosphoric acid mist emitted to the atmosphere will. contain concentrations
of trace impurities which are similar to those found in the phosphoric
acid product. For example, the arsenic level of unpurified acid is
approximately 11 ppm; this varies widely depending on the ore used to
produce the elemental phosphorus.25 Based on typical plant particulate
emissions (see Chapter 5), arsenic emissions can be calculated to be less
than 0.1 g/h (0.0002 Ib/h).
As indicated in the previous discussion, the major source of emissions
to the atmosphere is the exit of the control equipment. Other pollution
sources are the combustion chamber and the acid purification system (see
18
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TABLE 4-5. TYPICAL STACK EFFLUENT CHARACTERISTICS]2»21»26
Characteristic
Typical value
Chemical composition
Moisture content
Opacity
Particle density
Particle size
Mass median diameter
Toxidty - TLVb
Solubility
Stack flow rate
Stack temperature
Stack height
Stack diameter
H3P04, H20, NOX, air
10 to 60 percent3
0 to 100 percent
1.57 to 1.68 g/cm3
0.4 to 2.6 microns
1.6 microns
Irritant; 1.0 mg/m c
Soluble In water; decomposes In alcohol
1.6 to 14.3 nr/s (3,400 to 30,200 scfra)
900 to 4,100 m3/Mg product
(35,000 to 160,000 scf/ton product)
7.1 m3/s (15,000 acfm)d
60°C (140°F)d
23 m (75 ft)d
1.2m (4 ft)d
^Usually in the range of 40 to 50 percent.
°TLV = Threshold Limit Value.
jJNot to be exceeded for an 8-hr period.9C
Average from NEDS printout (11/13/79) /b
19
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Figure 4-1). High temperature combustion is conducive to formation of
nitrogen oxides. The quantity of nitrogen oxides depends on flame tempera-
ture, residence time, and excess air. Nitrogen oxides are only a minor
12
pollution problem in the thermal process phosphoric acid industry.
Acid purification is a separate process to remove heavy metals
(e.g., arsenic) to meet food grade specifications. Hydrogen sulfide
(H2S) is the emitted pollutant of this process. Pollution control for
this process is commonly used and relatively inexpensive. The least
expensive and most commonly used method vents the exhaust gases from the
acid purification plant to the phosphorus furnace; this incinerates the
H9S to form SO.-,. Another method uses sprays of weak solutions of soda
1 ?
ash. Most phosphoric acid plants have acid purification systems and are
not reported to have a pollution problem. One data source reports hydrogen
sulfide concentrations in the range of 10 to 2500 ppm for short periods
12
of time.
20
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5.0 AIR EMISSIONS
5.1 PLANT AND PROCESS EMISSIONS
Emission test data for specific plants were requested from state and
local control agencies, Individual plants, and pollution control equipment
vendors. Additional emission data were obtained from EPA's National
Emissions Data System (NEDS), EPA Publication No. AP-48, and other litera-
ture sources.12»26»27
Thermal process phosphoric add plants emit participates, mainly in
the form of acid mist, and trace amounts of nitrogen oxides (NOX) and
hydrogen sulflde (H2S). Acid mist is formed in the thermal process by
gas cooling and by water/acid addition.12 Only parti oilate is considered
to be a significant emission (see Chapter 7).
Table 5-1 shows estimated particulate emissions from a typical
thermal phosphoric acid plant and the data used in the calculations.
Average plant production rate was calculated by dividing total 1978 U.S.
production of P20g by the number of plants in operation that year. This
production rate (in tons P205/yr) was converted to an average plant
phosphorus burning rate (tons P/h). The typical burning rate is used in
the typical process weight equation:
E = 4.1 p°-67
where E = allowable particulate emissions, in Ib/h, and
p = process weight rate, 1n tons P/h
This typical process weight rate equation is applicable to 10 of the
20 operational plants in the U.S.
Data obtained from state agencies contacted in this survey Indicated
that phosphoric add plants commonly emit less participate than 1s allowed
by SIP's. Using emission data provided by four state agencies it was
determined that plants emit an average of 60 percent less particulate
than 1s allowed by the state SIP's. Table 5-1 presents the actual
emission level In addition to the allowable SIP level.
21
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TABLE 5-1. PARTICULATE EMISSIONS FROM A TYPICAL THERMAL PROCESS
PHOSPHORIC ACID PLANT
basis
Production rate: 27,250 Mg P205/yr (30,040 tons P205/yr)
Process weight rate: 1.50 Mg P/h (1.65 tons P/h)
11,900 Mg P/yr (13,110 tons P/yr)
Operating rate: 330 working days/yr
7,290 h/yr
Typical plant emissions (as 100% ^5)
Uncontrolled: 1,040 kg/h (2,300 Ib/h)
8,200 Mg/yr (9,100 tons/yr)
SIP: 2.6 kg/h (5.73 Ib/h)
20.6 Mg/yr (22.7 tons/yr)
Actual: 1.04 kg/h (2.3 Ib/h)
8.2 Mg/yr (9.1 tons/yr)
22
-------
The average production for a thermal phosphoric acid plant is 27,250 Mg
(30,040 tons) of 100 percent P205 per year. Average allowable emissions
are 2.6 kg of P20g/h (5.73 Ib/h). Applying a 60 percent reduction, the
emissions from a typical plant are 1.0 kg of PjAj/h ^'^ Ib/h).
No uncontrolled plants exist in the United States because it is not
profitable for the plants to lose the phosphoric acid mist to the atmos-
phere. Back calculating from a 99.9 percent control efficiency,
uncontrolled emissions for a typical plant are 1,040 kg of P205/h
(2,300 Ib/h) or 8,200 Mg of P205/yr (9,100 tons/yr).
5.2 TOTAL NATIONAL EMISSIONS
Baseline nationwide emissions (calculated using process weight
equations) are 412 Mg of P205 (454 tons/yr) or 52 kg of P205/h (114 Ib/h),
if all 20 existing plants meet state regulations. By applying a
60 percent reduction, the actual total nationwide emissions are estimated
to be 165 Mg of P20g/yr (182 tons/yr).
23
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6.0 EMISSION CONTROL SYSTEMS
6.1 CONTROL APPROACHES
Control equipment is used by the industry for recovery of product as
well as for air pollution control. It is difficult to determine where
economic product recovery ends and control of air pollution begins. The
equipment used extensively by the thermal process industry to recover
phosphoric acid or to control emissions includes: packed towers,
electrostatic precipitators, scrubbers, fiber mist eliminators, and wire
12 28 29
mesh contactors. c>to>" As indicated in Table 6-1, each of the
20 operational plants use an average of two types of equipment, and no
operational plant uses an electrostatic precipitator.
The following paragraphs describe the characteristics of each device
used for collecting acid mist. Criteria for selection of suitable control
equipment are: (1) collection efficiency required for economic product
recovery, (2) pressure drop across the control equipment, (3) capital and
operating costs, (4) frequency of equipment maintenance and repair, and
(5) particle size of the effluent to be collected.
6.1.1 Packed Towers
Packed towers (also called packed scrubbers) have been used in the
industry for many years. Basically, a packed tower is a vertical vessel
with packing material. The packing material, such as Raschig rings or
coke, provides surface area for interaction of liquid and gas phases.
Gas enters the bottom of the tower and is contacted countercurrently in
the packed tower with water or dilute acid. Typical gas flow rates range
from 0.9 to 2.0 m/s (3 to 6.5 ft/s), and packed material height ranges
from approximately 1.2 to 2.4 m (4 to 8 ft). Packing should provide
maximum surface area and minimum void area. Uniform gas distribution is
29
also essential for optimum collection efficiency.
The collection efficiency of a packed tower is about 90 percent.
Efficiencies of 98 percent and higher have been obtained by using two
24
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TABLE 6-1. SUMMARY OF CONTROL EQUIPMENT APPLIED
TO OPERATIONAL PLANTS
Number of operational
Control equipment type plants with control equipment*
Pack tower 7
Scrubber 8
Cyclone separator 2
Fiber mist eliminators 11
Wire mesh contactors 11
(Demlster)
aFor 20 operational plants listed in Table 4-1.
25
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packed towers in series. A pressure drop of 30 in. W.G. might be expected
through a system of two packed towers in series.
6.1.2 Electrostatic Precipitators
Electrostatic precipitators (ESP's) were used extensively by the
q
Tennessee Valley Authority (TVA) in thermal process acid plants. Corro-
sion is the biggest problem with the application of ESP's in this
29
industry. Presently no ESP's are used at operational thermal process
phosphoric ac-id plants.
The ESP operates at an approximate pressure drop of 0.12 kilopascal
(kPa) (0.5 in. W.G.). The reported collection efficiency for six instal-
?1
lations ranges from 96.3 to 99.9 percent. An installation of two ESP's
29
in series achieved a collection efficiency of 99.15 percent.
6.1.3 Scrubbers
Wet scrubbers are widely used for acid mist collection and operate
with high collection efficiencies. Water and/or weak acid is used as the
scrubbing agent. Collection efficiency is directly related to pressure
12 ?9
drop. Efficiency typically ranges from 98 to 99 percent. '
Venturi scrubbers, an orifice type wet scrubber, are especially
effective for the collection of particles characteristic of the acid mist.
They also have lower operating costs than ESP's and some other control
29
equipment if the collected sludge is disposed of without clarification.
However, the high cost of electric power to operate fans and to pump water
may be a disadvantage for the use of venturi scrubbers in new applications.
Pressure drops across the venturi scrubber have been reported in the range
of 6.2 to 15 kPa (25 to 60 in. W.G.).21'29
Some plants have installed a mist eliminator after the scrubber.
This combination increases collection efficiency to greater tha'n
99.9 percent.
6.1.4 Fiber Mist Eliminators
Glass fiber mist eliminators have been developing as a type of
30 31
collection device since the late 1950's. ' This control equipment has
been applied to various chemical processes, including sulfuric acid
plants, thermal process phosphoric acid plants, chlorine plants, nitric
26
-------
acid plants, and plants emitting ammonium chloride fume or bacteria
31
particles.
A mist eliminator consists of vertical elements in a vertical
cylinder. Unclean gas enters at the top or side of the cylinder, and
clean gas leaves the side or top. The eliminator has a drain at the
bottom of the cylinder to outlet the collected weak acid.
Two criteria must be met to ensure effective operation of fiber mist
eliminators: (1) the gas stream should not contain excessively large
particles and (2) there should be uniform gas flow through the mist
eliminator. The mist eliminator is frequently used after another type of
control device.
Collection efficiency has been reported in the range of 95 to
99.98 percent on particles smaller than one micron, with pressure drops
in the range of 1.2 to 5.0 kPa (5 to 20 in. W.G.).12'31
6.1.5 Wire Mesh Contactors
Wire mesh contactors (or pads) are the newest type of control equipment
for phosphoric acid mist. The wire mesh contactor was developed by Otto
H. York, Inc. and FMC Corporation under the registered trademark of
32
"Demister. The first commercial unit was operational in July 1964 and
consisted of two stainless steel wire mesh contactors in series. This
type of collection equipment is compact and has no moving parts. Collected
acid drains by gravity to a tank.
Outlet mist loading is directly related to the pressure drop for a
particular mesh material. The wire mesh contactor, like the fiber mist
eliminator, is most suitable to applications where the unclean gas does
not contain insoluble solids which might cause plugging of the wire mesh
pads.
The design collection efficiency of the wire mesh contactor is
99.9+ percent. Pressure drop ranges from 5 to 10 kPa
(20 to 42 in. W.G.).29'32
6.2 ALTERNATIVE CONTROL TECHNIQUES
Several combinations of control equipment are used by the thermal
process phosphoric acid manufacturing industry. The most widely used
combination is some form of packed tower or scrubber with a fiber mist
27
-------
eliminator or wire mesh contactor. This type of control system typically
has a design efficiency of 99.9+ percent.
6.3 "BEST SYSTEMS" OF EMISSION REDUCTION
The most effective system (99.9+ percent) of emission control is
probably the combination of a packed tower or scrubber with a form of
fiber mist eliminator or wire mesh contactor. This type of control
system, as indicated earlier, is the most frequently used system and has
been installed most recently to replace other forms of control equipment
(e.g., ESP's). In addition, it is economical to add these devices to
existing equipment.
28
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7.0 EMISSION DATA
7.1 AVAILABILITY OF DATA
The availability of emission data was determined through telephone
and letter contacts to state and local control agencies as well as the
individual thermal process phosphoric acid plants. The data available
was for particulate emissions, except for a small amount of data on NO ,
rt
HC, and CO provided by the State of California. Nineteen state and local
agencies were contacted. All plants/companies (see Table 4-1) were
contacted for specific process and emissions data. Particulate and
nitrogen oxide emission data prior to 1968 for 25 plants are reported in
EPA Publication No. AP-48.12 These data are not included in this survey.
Typical plant and nationwide emissions were calculated using the
method described in Chapter 5. Allowable emissions for a typical plant
under an SIP were calculated to be 2.6 kg/h (5.73 Ib/h); actual emissions
from a typical plant were an average of 60 percent lower, or 1.04 kg/h
(2.3 Ib/h). Data provided by states and plants show that plant emissions
range from 0.2 to 14 kg/h (0.43 to 30 Ib/h).
Operating practices, including changes in the grade of acid produced,
have little effect on emissions of acid mist. The acid mists are very
hygroscopic; thus, visible emissions are readily noticeable if high
collection efficiencies are not achieved.
7.2 SAMPLE COLLECTION AND ANALYSIS
7.2.1 Particulate
Particulate (phosphoric acid mist) emissions may be measured using
EPA Reference Method 5 as described in 40 CFR 60, Appendix A11 or EPA
Reference Method 5 with slight modifications as described in detail in
EPA Publication No. AP-48.12 These modifications include: (1) removal
of the filter and filter support; (2) use of 250 ml and 150 ml of deionized
water in the first and second impingers, respectively, in place of 200 ml
29
-------
of distilled water; and (3) termination of sampling before water entrainment
occurs in the third impinger.
Two sample analyses methods are also described in detail in EPA
1 o
Publication No. AP-48. These are: (1) a spectrophotometric determination
(i.e., color-metric method), as adopted by the Association of Official
Analytical Chemists and (2) an American Chemical Society (ACS) acid-base
titration method adapted for these samples. Both methods are specifically
applicable to the samples collected using the modified EPA Reference
Method 5 for effluents from thermal process phosphoric acid plants.
7.2.2 Opacity, Nitrogen Oxides, and Hydrogen Sulfide
EPA Reference Method 9 (as described in 40 CFR 60, Appendix A)'is
available for determination of visible emissions. The plume from
thermal process phosphoric acid plants usually contains high moisture
content (40 to 50 percent moisture), and appropriate procedures (i.e.,
reading plume after steam dissipates) should be followed as described in
the method.
EPA Reference Method 7 (described in 40 CFR 60, Appendix A) is
available for the collection and analysis of nitrogen oxide emissions.
EPA Reference Method 11 (described in 40 CFR 60, Appendix A) could
be used for determination of hydrogen sulfide content of emissions from
the acid purification system. Some modifications might be necessary to
convert this method to this source category.
30
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8.0 STATE AND LOCAL EMISSION REGULATIONS
The following paragraphs provide information on pertinent state and
local agency regulations. These data were compiled from (1) telephone •
contacts and letter requests to the specific agencies and (2) the
•5^
Environment Reporter.
Thermal process phosphoric acid plants are in operation in 14 state*
(see Table 4-1). All 14 states have emission regulations for particulates
and visible emissions (opacity). These regulations are summarized in
Table 8-1. None of the states has developed any emission standards
specific to new or existing thermal process phosphoric acid manufacturing
plants; most state regulations categorize this source as an "industrial"
or "manufacturing" process. Although six of the states regulate sulfuric
acid mist, no state regulates phosphoric acid mist.
The majority of the states listed in Table 8-1 use the following
process weight rate equations to establish allowable participate emissions:
E = 4.0 p°-67 p^O tons
E = 55.0 p°'11-40 p>30 tons
where E = allowable particulate emission rate, in Ib/h
p = process weight rate, in tons/h
Several states have used the above equations to calculate emission
limits for specific process weight rates. These states provide tables
and/or graphs for determining allowable emissions. Other states have
developed their own process weight rate tables and equations. The
California South Coast Air Quality Management District (SCAqMD), for
example, uses a table which requires lower emissions than the equations
of the majority of the other states. An average sized plant (burning
1.65 tons of elemental phosphorus per hour) which would be allowed to
emit 5.73 Ib of particulate per hour using the above equations would be
limited to emitting 4.86 Ib of particulate per hour in the SCAQMD.
Most states with operating thermal process phosphoric acid plants
limit opacity to 20 percent but allow deviations above this level for a
small percentage of time in an hour or day.
All states that supplied allowable and actual emission data indicated
that thermal process phosphoric plants were operating well within applicable
31
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TABLE 8-1. SUMMARY OF STATE AIR POLLUTION REGULATIONS
California
Bay Area
South Coast
Georgia
Illinois
Indiana
Kansas
Michigan
Missouri
Parti cul ate
Equation Set la
Process weight
rate table 405,
Type A
E=4.1p°-67
Equation set 2
Equation set 1
Equation set 1
Equation set 1
\
Equation set 1
Visibility
£20, exception
£20, exception
£20, exception
£30, exception
£40, exception
— — ••
£20, exception
£20, exception
Air pollution
regulation reference
Bay Area Air Control District
Reg. IV, September 1977
Rules and Regulations South Coast
Air Quality Management District,
Reg. IV, September, 1977
Georgia Air Quality Control
Rules, Chapter 391-3-1 ,
November 1975
Illinois Stationary Sources
Standard; May 1979.
Rule 201, 202, 1977.
Indiana Air Pollution
Control Regulations, APC-3,
May 1979
Kansas Air Pollution Control
Regulations, Section 28,
January 1974
Michigan Administrative Rules
for Air Pollution Control
Regulations, Section 28,
January 1974
Missouri Air Pollution
Control Regulation,
10 CSR 10-5, December 1979
-------
TABLE 8-1. SUMMARY OF STATE AIR POLLUTION REGULATIONS
(continued)
Particulate
Visibility
Air pollution
regulation reference
New Jersey
£.02 g/dscf
or 99% reduction
520, exception
New Jersey Regulations on
Air Pollution from Manufacturing
Processes. Subchapter 6. May 1977
Ohio
Equation set 1
£20, exception
Ohio Particulate Matter Standards,
September 1978
Pennsylvania
$.02 g/dscf d
or equation 3
£20, exception
Pennsylvania Standards for
Contaminants, Section 123,
July 1978
South Carolina Equation set 1
South Carolina Air Pollution
Control Regulations and Standards,
Section 6t May 1978
GJ
to
Tennessee
Equation set 1
£20, exception
Tennessee Air Pollution Control
Regulations, Chapter 1200-3,
February 1977
Texas
Equation set 4
£30, exception
Texas Regulation 1: Control of
Air Pollution From Visible
Emissions and Particulate Matter,
Section 131. May 1979
Wisconsin
Equation set 5
£20, exception
Wisconsin Air Pollution Control
Rules. NR 154.11. May 1. 1977
aEquation Set 1:
E = 4.1p°-67
E =
p£30 tons/h
p>30 tons/h
E = allowable emission rate, in Ib/h.
p = process weight rate, in tons/h.
-------
TABLE 8-1. SUMMARY OF STATE AIR POLLUTION REGULATIONS
(concluded)
CO
•* e
This equation alone is used for all existing equipment. New equipment is subject to the restrictions
of both equations in Equation Set 1.
Equation Set 2:
E = 2.45p°-534 pg450 tons/h
E = 24.8p°-16 p>450 tons/h
Existing equipment is subject to the restrictions of Equation Set 1.
Equation Set 3:
A = 0.76E0-72
A = allowable emissions
E = FxW
F = process factor, 6 Ib/ton P burned for HgPO,
W = production/charging weight
Equation Set 4:
E = 3.59p°-985 pS20 tons/h
E = 25.4p°«287 p>20 tons/h
Further reductions are required if stack height is less than the standard effective stack height.
Equation Set 5:
E = 3.59p°-62 pS30 tons/h
E = 17.31p°-16 p>30 tons/h
^Most states allow opacity to exceed restricted levels for brief periods per hour or day.
-------
participate regulations. On the average, the actual emissions of a plant
were 60 percent below the allowable state emissions. Only two states
reported any history of problems with any of their thermal process
phosphoric acid plants.
Nitrogen oxides are a potential emission from the combustion chamber
in the thermal process. No state has regulations which are directly
applicable to thermal process phosphoric acid plants. Georgia has a
regulation which applies to any nonfuel-burning equipment. For stack
height less than 300 ft, the allowable emissions are:
E = 9300 (hs/300)3
where E = allowable NO emissions, in Ib/h, and
/\
h = stack height, in ft
Hydrogen sulfide emissions are generated in the acid purification
unit of a thermal process plant. Three of the fourteen states have
regulations for hydrogen sulfide emissions; the emission limits are
0.06 ppm, 0.03 ppm, and 0.08 ppm for the states of California (Bay Area),
Missouri, and Texas, respectively. Each of the three state regulations
specify periods of time (3 to 30 min.) for which the limit should not be
exceeded.
35
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9.0 REFERENCES
1. U.S. Environmental Protection Agency. Code of Federal Regulations.
Title 40, Chapter I, Subchapter C, part 60.14. Washington, D.C.
Office of the Federal Register. August 3, 1978.
2. U.S. Environmental Protection Agency. Code of Federal Regulations.
Title 40, Chapter I, Subchapter C, part 60.15. Washington, D.C.
Office of the Federal Register. December 16, 1975.
3. U.S. Environmental Protection Agency. Code of Federal Regulations.
Title 40, Chapter I, part 60.16. Washington, D.C. Office of the
Federal Register. August 21, 1979.
4. Furia, T. E. (ed.). Handbook of Food Additives. Cleveland, Ohio.
The Chemical Rubber Co. 1968. p. 266-268.
5. Bridges, J. D. Fertilizer Trends. Tennessee Valley Authority.
National Fertilizer Development Center. Muscle Shoals, AL.
Bulletin Y-150. January 1980.
6. Rushton, W. E. Phosphoric Acid Plant Problems: Defluorination of
Wet Process Acid. Chemical Engineering Progress. Pages 52-54.
November 1978.
7. Hartlapp, G. Phosphoric Acid by the Furnace Process. In: Phosphoric
Acid, Part II, Slack, A.V. (ed.). New York, Marcel Dekker, Inc.
1968. p. 927-982.
8. U.S. Environmental Protection Agency. National Emissions Inventory
of Sources and Emissions of Phosphorus. EPA-450/3-74-013. Research
Triangle Park, N.C. May 1973. 54 p.
9. Telecon. Scott, William. C., Jr., Tennessee Valley Authority, with
Maxwell, C. M., Midwest Research Institute. December 10, 1979.
Status of thermal process phosphoric acid industry.
10. Jones, E. D., III. Phosphorus as a Factor in the United States Economy,
In: Environmental Phosphorus Handbook, Griffith, E. J. (ed.). New
York, John Wiley and Sons. 1973. p. 669-682.
11. U.S. Environmental Protection Agency. Code of Federal Regulations.
Title 40, Chapter I, Part 60, Appendix A. Washington, D.C. Office
of the Federal Register. July 1, 1979.
12. U.S. Department of Health, Education and Welfare. Atmospheric
Emissions from Thermal-Process Phosphoric Acid Manufacture. AP-48.
Research Triangle Park, N.C. October 1968. 68 p.
13. Mei.io and attachments from Maxwell, C. M., Midwest Research Institute,
to Anderson, L., EPA/ISB. January 11, 1980. Report of visit to
Monsanto Company (Augusta, Georgia, plant) on January 10, 1980.
36
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14. Memo and attachments from Maxwell, C. M., Midwest Research Institute,
to Anderson, L., EPA/ISB. January 18, 1980. Report of visit to
FMC Corporation (Carteret, New Jersey, plant) on January 7, 1980.
15. Stanford Research Institute. Chemical Economics Handbook. Menlo
Park, CA. August 1978, March 1979.
16. Phosphoric Acid. Chemical and Engineering News. April 30, 1979.
17. Phosphoric Acid. Chemical and Engineering News. February 25, 1980.
18. Lowenheim, F. A. and M. K. Moran. Industrial Chemicals. Fourth
Edition. New York, John Wiley and Sons. 1975. p. 628-657.
19. Katarl, V., G. Isaacs, and T. W. Devitt. Trace Pollutant Emissions
from the Processing of Non-Metallic Ores. U.S. Environmental
Protection Agency, Research Triangle Park, N.C. Publication
No. EPA-650/2-74-122. November 1974. Chapter 6 and Appendix F.
20. The Soap and Detergent Association. Phosphate Loading to the Great
Lakes from Detergents. New York, N.Y. September 21, 1979.
21. U.S. Environmental Protection Agency. Particulate Pollutant System
Study, Volumes I, II, and III. APTD-0743, 0744, and 0745. Research
Triangle Park, N.C. 1971.
22. Uaggaman, U. H. Phosphoric Acid, Phosphates and Phosphatic
Fertilizers. New York, Reinhold Publishing Corporation. 1952.
p. 158-173, 622-623.
23. U.S. Environmental Protection Agency. Air Pollution Engineering
Manual. AP-40. Research Triangle Park, N.C. May 1973. p. 734-737.
24. Legal, C. C. and 0. D. Myrick, Jr. History and Status of Phosphoric
Add. In: Phosphoric Acid, Part I, Slack, A. V. (ed.). New York,
Marcel Dekker, Inc. 1968. p. 1-90.
25. Letter from Liss, R. L., Monsanto Industrial Chemicals Company,
to Maxwell, C. M., Midwest Research Institute. January 29, 1980.
Response to plant visit on January 10, 1980.
26. U.S. Environmental Protection Agency, National Emissions Data System
(NEDS). Printout of Source Classification Codes 3-01-017-01 and
3-01-017-99. November 13, 1979.
27. U.S. Environmental Protection Agency. Compilation of Air Pollutant
Emission Factors. AP-42. Research Triangle Park, N.C. April 1973.
p. 5.11-1 - 5.11-2.
28. Brink, J. A. Jr., W. F. Burggrabe, and J. A. Rauscher. Fiber Mist
Eliminators for Higher Velocities. Chemical Engineering Progress.
60 (11): 68-73. November 1964.
37
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29. Spencer, E. F. Pollution Control in the Chemical Industry. In:
Industrial Pollution Control Handbook, Lund, H. F. (ed.). New York,
McGraw-Hill Book Company. 1971. p. 14-6 - 14-7.
30. Brink, J. A. Jr. New Fiber Mist Eliminator. Chemical Engineering.
p. 183-186. November 16, 1959.
31. J. A. Brink, Jr. Removal of Phosphoric Acid Mists. In: Gas
Purification Processes, Nonhebel, G., (ed.). London, George
Newnes, Ltd. 1964. p. 720-741.
32. Coykendall, J. W., E. F. Spencer, and 0. H. York. New High-Efficiency
Mist Collector. Journal of the Air Pollution Control Association
18:315-318. May 1968.
33. U.S. Department of Health, Education, and Welfare. Control Techniques
for Particulate Air Pollutants. AP-51. Washington, D.C.
January 1969. p. 19.
34. Stewart, J. U. Environment Reporter. Bureau of National Affairs, Inc.
Washington, D.C. 1979.
38
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing/
1. REPORT NO.
EPA/450-3-80-018
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
REPORT DATE
Source Category Survey: Thermal Process Phosphoric
Acid Manufacturing Industry
May 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
9. PE.
LREQBMING ORGANIZATION NAMjE_AND ADDRESS. _. . ,
Office of Air tfuaiity Planning and Standards
Environmental Protection Agency
Research Triangle Park, North Carolina 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-3059
12. SPONSORING AGENCY NAME AND ADDRESS , „ .
DAA for Air Quality Planning and Standards
Office of Air, Noise, and Radiation
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/200/04
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Phosphoric Acid Manufacture by the thermal process was examined to determine the
need for standards of performance in accordance with Section 111 of the Clean
Air Act. This document contains information gathered on the processes, pollutants,
and air pollution control equipment for the thermal process phosphoric acid
industry.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Pollution Control
Phosphoric Acid
Phosphoric Acid Mist
Thermal Process Phosphoric Acid
Furnace Process Phosphoric Acid
Air Pollution Control
13B
8. DISTRIBUTION STATEMENT
UNLIMITED
19. SECURITY CLASS (This Report/
UNCLASSIFIED
21. NO. OF PAGES
43
J20. SECURITV CLASS 'This page I
1 UNCLASSIFIED
•22. PRICE
EPA Form 2220-1 (R«v. 4-77) PREVIOUS tc/ifON is OBSOLETE
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