EPA-450/2-74-019a
BACKGROUND INFORMATION
FOR STANDARDS OF PERFORMANCE:
PHOSPHATE FERTILIZER INDUSTRY
VOLUME 1: PROPOSED STANDARDS
Emission Standards and Engineering Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
October 1974
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This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are
available free of charge to Federalemployees, current contractors and ,
grantees, and nonprofit organizations - as supplies permit - from the Air
Pollution Technical Information Center, Environmental Protection Agency,
Research Triangle Park, North Carolina 27711; or, for a fee, from the
National Technical Information Service, 5285 Port Royal Road, Springfield,
Virginia 22161.
Publication No. EPA-450/2-74-019a
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PREFACE
A- Pur p o s e of t h js Report
Standards of performance under section 111 of the Clean
Air Act-/ are proposed only after a very detailed investigation
of air pollution1 control 'methods available.to the affected ,
industry and the impact of their costs on'the "industry. This
report summarizes the information obtained from such a study
of the phosphate 'fertilizer industry. It is being distributed in
'connection with formal proposal of standards for that industry
in the- Federal' Register.- Its purpose is to explain.the
background and ba'sis of the proposal in "greater detail than
could be included in the Federal Register, and to facilitate
analysis of the proposal by interested persons, including those
who may not be. fami! i-ar with the many technical aspects of the
industry. For addi'tional information, for copies of documents , -
(other tKan published literature) cited in the Background
Information Document, or to comment on the proposed standards, ,
contact Mr. Don R. Goodwin,"Director, Emission Standards and
' Engineering Division, United States' Environmental Protection
Agency, Research Triangle Park, North - Carolina-27711" [(919)688-8146],
B. Authority for the Standards
Standards of performance for new stationary sources are
promulgated in accordance with section 111"of the Clean Air Act
(42 USC 1857c-6), as amended in 1970. Section 111 requires
!_/ Sometimes referred to as "new source performance
standards" (NSPS).
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the establishment of standards of performance for new stationary
sources of air pollution which "... may contribute significantly
to air pollution which causes or contributes to the endangerment
of public health or welfare." The Act requires that standards
of performance for such sources reflect "... the degree of
emission limitation achievable through the application of the best
system of emission reduction which (taking into account the cost
of achieving such reduction) the Administrator determines has
been adequately demonstrated." The standards apply only to
stationary sources, the construction or modification of which
commences after regulations are proposed by publication in
the Federal Register.
Section 111 prescribes three steps to follow in establishing
standards of. performance.
1. The Administrator must identify those categories of
stationary sources for which standards of performance
will ultimately be promulgated by listing them in the
Federal Register.
2. The regulations applicable to a category so listed must
be proposed by publication in the Federal Register within
120 days 'of its listing. This proposal provides interested
persons an opportunity for comment.
3. Within 90 days after the proposal, the Administrator
must promulgate standards with any alterations he deems
appropriate.
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It is important to realize that standards of performance,
by themselves, do not guarantee protection of health or welfare;
that is, they are not designed to achieve any specific air
quality levels. Rather, they are designed to reflect best
demonstrated technology (taking into account costs) for the
affected sources. The overriding purpose of the collective
body of standards is to maintain existing air quality and to
prevent new pollution problems from-developing.
Previous legal challenges to standards of performance for
Portland cement plants, steam generators, and sulfuric acid
plants have resulted in several court decisions-/ of importance
in developing future standards. In those cases, the principal
issues were whether EPA: (1) made reasoned decisions and
fully explained the basis of the standards, (2) made available
to interested part-ies the information on which the standards
were based, and (3) adequately considered significant comments
from interested parties.
Among other things, the court decisions established:
(1) that preparation of environmental impact statements,is not
necessary for standards developed under section 111 of the Clean
Air Act because, under that section, EPA must consider any
counter-productive environmental effects of a standard in
determining what system of control is."best;" (2) in considering
costs it is not necessary to provide a cost-benefit analysis;
27Port!ant Cement Association v Ruckelshaus, 486 F. 2nd
375 (D.C. Cir. 1973); Essex Chemical Corp. v Ruckelshaus, 486
F. 2nd 427 (D.C. Cir. 1973).
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(3) EPA is not required to justify standards that require different
levels of control in different-industries unless -such different
standards may be unfairly discriminatory; and (4) it is
sufficient for EPA to show that a standard can be achieved
rather than'that it has been achieved by existing sources.
Promulgation of standards ,of performance does not prevent
State or local agencies from adopting more stringent emission
limitations for the same sources. On the contrary section 116
of the Act (42 USC 1857-D-l) makes clear that States and other
political subdivisions may enact more restrictive standards..
Furthermore, for heavily"polluted areas, more stringent-standards .
may be required under section 110 of the Act (42 USC 1857c-5) in
order to attain or maintain national ambient air quality standards
prescribed under section 109 (42 USC 1857c-4).' Finally, section 116
makes clear that a-State may not adopt or enforce less stringent
standards than those adopted by EPA under section 111.
Although it is clear that standards of performance should be
in terms of limits on emissions where feasible,- an alternative
method of requiring control of air pollution is sometimes
necessary. In some cases physical measurement*bf emissions
from a new source may be impractical or exorbitantly expensive.
37'"Standards of performance,' ... refers to the degree of
emission control which can be achieved through process changes,
operation changes, direct emission control, or other methods. The
Secretary [Administrator] should not make a technical judgment
as to how the standard should be implemented. He should determine
the achievable limits and let the owner or operator determine the
most economical technique to apply." Senate Report 91-1196.
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for example, emissions of hydrocarbons from storage vessels for
' ~j : '
petroleum liquids are greatest during storage and tank filling/
The nature of the emissions (high concentrations for short
periods during filling and low concentrations for longer
periods during storage) and the configuration of storage tanks
make direct emission measurement highly impractical. Therefore,
a more practical approach to standards of performance for
storage vessels has, been equipment specification.
C. Selection of Categories of Stationary Sources
Section 111 directs the Administrator to publish and from
time to time revise a list of categories of sources for which
standards of performance are to be proposed. .A category is to
be selected "... if [the Administrator] determines it may contribute
significantly to air pollution which causes or contributes to the
endangerment of public health or welfare."
Since passage of the Clean Air Amendments of 1970, considerable
attention has been given to the development of a system for
assigning priorities to various source categories. In brief,
the approach that has evolved is as follows.
First, we assess any areas of emphasis by considering the
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broad EPA strategy for implementing the Clean Air Act. Often,
these "areas" are actually pollutants which are primarily emitted
by stationary sources. Source categories which emit these
pollutants are then evaluated and ranked by a process involving
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such factors as (1) the level of emission control (if any)
already required by State regulations; (2) estimated levels
of control that might result from standards of performance for the
source category; (3), projections of growth and replacement
of existing facilities for the source category; and (4) the
estimated incremental amount of air pollution that could be_,
prevented, in a preselected future year, by standards of
performance for the source category. -,.>'..
After the relative ranking is complete, an estimate
must be made of a schedule of activities required to develop
a standard. In some cases, it may not be feasible to immediately
develop a standard for a source category with a very high
priority. This might occur because a program of research
and development is needed or because techniques for sampling
and measuring emissions may require refinement before study
of the industry can be initiated. The schedule of activities
must also consider differences in the time required to complete
the necessary investigation for different source categores.
Substantially more time may be necessary, for example, if a
number of pollutants must be investigated in a single source
category. Even late in the development process the
schedule for completion of a standard may change. For
example, inability to obtain emission data from
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well-controlled sources in time to pursue the development
process in a systematic fashion may force a change in
scheduling.
Selection of the source category leads to another major^
decision: determination of the types of sources or facilities
to which the standard will apply. A source category often
has several facilities that cause air pollution. -Emissions
from some of these facilities may be insignificant and, at the
same time, very expensive to control. An investigation of
economics may show that, within the costs that an owner could
reasonably afford, air pollution control is better served by
applying standards to the more severe pollution problems. For
this reason (or perhaps because there may be no adequately
demonstrated system for controlling emissions from certain
facilities), standard's often do not apply to all sources within
a category. For similar reasons, the standards may not apply
to all air pollutants emitted by such sources. Consequently,
although a source category may be selected to be covered by a
standard of performance, treatment of some of the pollutants or
facilities within that source category may be deferred.
D. Procedure for Development of Standards of Performance
Congress mandated that sources regulated under section. Ill
of the Clean Air Act be required to utilize the best practicable
air pollution control technology that has been adequately
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demonstrated at the time of their design and construction. In so
doing, Congress sought to:
1. maintain existing high-quality air,
2. prevent new air pollution problems, and
3. ensure uniform national standards for new facilities.
The selection of standards of performance to achieve the
intent of Congress has been surprisingly difficult. In general,
the standards must (1) realistically reflect best demonstrated
control practice; (2) adequately consider the cost of such control;
(3) be applicable to existing sources that are modified as well
as"new installations; and (4) meet these conditions for all
variations of operating conditions being considered anywhere in
the country.
A major portion of the program for development of standards
is spent identifying the best system of emission reduction which
"has been adequately demonstrated" and quantifying the emission
rates achievable with the system. The legislative history of
section 111 and the court decisions referred to above make clear
that the Administrator's judgment of what is adequately demonstrated
is not limited to systems that are in actual routine use.
Consequently, the search may include a technical assessment
of control systems which have been adequately demonstrated but
?
for which there is limited operational experience. To date,
determination of the "degree of emission limitation achievable"
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has been commonly based onj (but not restricted to) results
.of tests of emissions^ from existing sources. This has , - ,-.
required worldwide investigation and measurement of emissions
from control systems. Other countries with heavily populated, - 4-
industrialized areas have sometimes developed more effective
systems of control than those used in the United States.. .ซ.
Because the best demonstrated systems of emission reduction may
not be in widespread use, the data base upon which the standards ,
are established will necessarily be somewhat'limited. Test
data on existing well-controlled sources are an obvious starting
point in developing emission limits for new sources/. However,
since the control of existing sources generally represents
retrofit technology or was originally designed to meet an
existing State or local regulation, new sources may be able
to meet more stringent emission standards. Accordingly, other
information must be considered and judgment is necessarily
involved in setting proposed standards.
Since passage of the Clean Air Amendments of 1970, a
process for the development of a standard has evolved. In
general, it follows the guidelines below.
1. Emissions from existing well-controlled sources
are measured.
2. Data on emissions from such sources are assessed with
consideration of such factors as: (a) the representativeness
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of the source tested (feedstock, operation, size, age,
etc.); (b) the age and maintenance of the control
equipment tested (and possible degradation in the
efficiency of control of similar new equipment even
with good maintenance procedures); (c) the design
uncertainties for the type of control equipment being
considered; and (d) the degree of uncertainty affecting
the judgment that new sources will be able to achieve
similar levels of control.
3. During development of the standards, information from
pilot and prototype installations, guarantees by vendors
of control equipment, contracted (but not yet constructed)
projects, foreign technology, and published literature
are considered, especially for sources where "emerging"
technology appears significant.
4. Where possible, standards are set at a level that is
achievable with more than one control technique 'or
licensed process.
5. Where possible, standards are set to encourage (or at least
permit) the use of process modifications or new processes
as a method of control rather than "add-on" systems of
air pollution control.
6. Where possible, standards are set to permit use of
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systems capable of controlling more than one pollutant
(for example, a scrubber can remove both gaseous and
particulate matter emissions, whereas an electrostatic
precipitator is specific to particulate matter).
7. Where appropriate, standards for visible emissions are
established in conjunction with mass emission standards.
In such cases, the standards are set in such a way that
a source meeting the mass emission standard will be able
v^
to meet the visible emission standard without additional
)
controls. (In some cases, such as fugitive dust, there
is no mass standard).
Finally, when all pertinent data are available, judgment
is again required. Numerical tests may not be transposed directly
into regulations. The design and operating conditions of those
sources from which emissions were actually measured cannot be
reproduced exactly by each new source to which the standard of
performance will apply.
E. How Costs are Considered
Section 111 of the Clean Air Act requires that cost be
considered in setting standards of performance? To do this requires
an assessment of the possible economic effects of implementing
various levels of control technology in new plants within a
given industry. The first step in this analysis requires the
generation of estimates of installed capital costs and annual
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operating costs for various demonstrated control systems,
each control system alternative having a different overall
control capability. The final step in the analysis is to
determine the economic impact of the various control alternatives
upon a new plant in the industry. The fundamental question to
be addressed in this step is whether or not a new plant would
be constructed given that a certain level of control costs would
be Incurred. Other issues,that would be analyzed in this step
would be the effects of control costs upon product prices and the
effects on product and raw material supplies and producer
profitability.
The economic impact upon an industry of a proposed standard
is usually addressed both in absolute terms and by .comparison
with the control ,costs, that.would be incurred as a result
of compliance with typical existing State control regulations.
This incremental approach is taken since a new plant would
be required "to comply with State regulations in the absence
of a Federal standard of performance. This approach requires
a detailed analysis of the impact upon the industry resulting
from the cost differential that usually exists between the
standard of performance and the typical State standard.
It should be noted that the costs for control of air
pollutants are not the only control costs considered. Total
environmental costs for control of water pollutants as well
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as air pollutants are analyzed wherever possible.
A thorough study of the profitability and price-setting
mechanisms of the industry is essential to the analysis so
that an accurate estimate of potential adverse economic impacts
can be made. It is also essential to know the capital requirements
placed on plants in the absence of Federal standards of performance
so that the additional capital requirements necessitated by these
standards can be placed in the proper perspective. Finally, it
is necessary to recognize any constraints on capital availability
within an industry as this factor also influences the ability
of new plants to generate the capital required for installation
pf the additional control equipment needed to meet the standards
of performance. ^
The end result of the analysis is a presentation of costs
and potential economic impacts for a series of control
alternatives. This information is then a major factor which
- - t '-'
the Administrator considers in selecting a standard.
F. Impact on Existing Sources
Proposal of standards of performance may affect an existing
source in either of two ways. First, if modified after
proposal of the standards, with a subsequent increase in
air pollution, it is subject to standards of performance as
,,if it Were a new source. (Section 111 of the Act defines a
new'source as "any"stationary source, the instruction or
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modlflcation of which is commenced after the regulations are
proposed.")'
Second, promulgation of a'Standard of performance requires
States to establish standards of performance for the same pollutant
for existing sources in the same industry under section 111(3) of
the Act; unless the pollutant limited by the standard for new
sources is one listed under section 108 (requiring promulgation of
national ambient air quality standards) or one listed as a
hazardous pollutant under section 112. If a State does not act,
EPA must establish such standards. Regulations prescribing
procedures for control of existing sources under section lll(d)
will be proposed as Subpart B of 40 CFR Part 60.
G. Revision of Standards of Performance
Congress was aware that the level of air pollution control
ach-ievable by any industry may improve with technological
advances.. Accordingly, section 111 of the Act provides that
*
the Administrator may revise such standards from time to time.
Although standards proposed and promulgated by EPA under section 111
are designed to require installation of the "... best system of
emission reduction ... (taking into account the cost)..."
the standards will be reviewed periodically. Revisions will be
proposed and promulgated as necessary to assure that the standards
37Specific provisions dealing with modifications to existing
facilities are being proposed by the Administrator under the
General Provisions of 40 CFR Part 60.
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continue to reflect the best systems that become available
in the future. Such revisions will not be retroactive but
will apply to stationary sources constructed or modified after
proposal of the revised standards.
H. Why Standards of Performance for Fluorides?
Two questions are basic to the control of fluorides: why
control them and why do so with section 111?
The deleterious effects of fluoride on both animals and
vegetation have been extensively documented.- The effect on
animals is through the digestive tract when relatively large
quantities of contaminated.vegetation are ingested. Citizens,
both privately and in groups, have sought relief from fluoride
damage through suits against the alleged industrial sources.
In one case, a citizens' group sent to EPA data which support
the need for Federal regulation of fluorides. State agencies
have recorded and acted on numerous public complaints on the
T^-
adverse effects of fluorides on the growth, yield, quality, and
appearance of marketable goods such as fruit, grains, leafy
vegetables, pine trees, ornamental plants, and dairy cattle.
In determining that there is a need to control fluoride
emissions into the atmosphere, the Administrator relied heavily
upon the report Fluorides, which was prepared for the Agency by
5/ National Academy of Sciences, Fluorides, prepared for
EPA under Contract No. CPA 70-42, Washington, p. C. 20418, 1971
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the National Academy of Sciences in 1971. Jn preparing this
report, the Academy made a concerted effort to evaluate the
world literature on the subject and distill the best scientific
knowledge available on the biological effects of fluorides.
This report concludes: "Current knowledge indicates that air-
borne fluoride presents no direct hazard to man, except in
industrial exposure. However, through the commercial, aesthetic,
and ecologic functions of plants, fluoride in the environment
may indirectly influence man's health and well being." After
considering the available information on fluorides, the Administrator
has concluded that, even though present evidence indicates that
fluorides in the range of ambient concentrations encountered under
worst conditions do not damage human health through inhalation,
they do present a serious risk to public welfare- and v/arrant
control. Fluoride emissions affect public welfare not only through
their effects on aesthetic values, but also through a decrease in
the economic value of crops which are damaged by exposure to
fluorides and through adverse effects on the health of animals
ingesting vegetation which has accumulated excessive amounts of
fluorides.
ง7As used in the Clean Air Act,
includes, but is not limited to, ". .
crops, vegetation, man-made materials,
visibility, and climate, damage to and
and hazards to transportation, as well
and on personal comfort and well being
42 U.S.C. 1857h(h) as amended.]
xviii
the term "effects on welfare"
, effects on soils, water,
animals, wildlife, weather,
deterioration of property,
as effects on economic values
," [See section 302(h)
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Private citizens and citizens' groups have actively sougnt
means to alleviate fluoride damage. One citizens' group, Center
for Science in the Public Interest, has written the Agency
describing at great length the need for fluoride regulations.
A number of lawsuits have been initiated which are concerned with
fluoride effects on agricultural products, and at least 20
citizens' suits have been filed against aluminum plants that emit
fluorides.
The Administrator's decision to control fluoride emissions at
the national level was based on the following:
1. The present national ambient air quality standards for
particulate matter,'standing alone, would not provide
adequate welfare protection against the effects of
fluoride for two reasons: (a) fluorides are emitted
as both'particulate matter and gases, and (b) since
the ambient standard is for "non-specific" particulate
matter, compliance with that standard would not ensure
fluoride concentrations sufficiently low to prevent
damage.
2. Although many states have adopted fluoride control
regulations, major sources of fluoride emissions exist
in several states with no fluoride regulations.
3. A uniform national standard of performance for new
sources would discourage movement of major fluoride
emitters to states with no fluoride regulations.
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4. Primary aluminum reduction plants, one of the major
sources of fluoride emissions, are commonly located
near major waterways that comprise borders between
states. The potential for interstate conflict concerning
control of emissions from such plants has prompted
Federal investigations in the past, and in at least one
case a state has requested initiation of abatement
conference proceedings under section 115 of the Act
[42 U.S.C. 1857d].
An EPA report entitled "Preferred Standards Path Report for
Fluorides" (November 1972) contains a detailed discussion of the
"advantages and disadvantages of each regulatory option provided
to the Administrator under the Act to control fluoride emissions
on a national level. In general, the Administrator concluded
that fluorides should be regulated under section 111 of the Act
for the following reasons:
1. In contrast with the problems presented by the six
pollutants for which national ambient air quality
standards have been promulgated, the fluoride problem
is highly localized in the vicinity of major point
sources in agricultural areas and is not complicated
by the presence of numerous mobile sources. Promulgating
a national ambient air quality standard for fluorides
77A copy of this report is available for inspection during
normaT business hours at the Freedom of Information Center,
Environmental Protection Agency, 401 M Street, S.W., Washington, D. C.
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under section 109 would require states to submit
implementation plans to attain and maintain such
standards. Because of the complex problems involved
in relating emissions to ambient levels, most plans
would include regulations based on best demonstrated
control technology. The same result can be accom-
plished more directly and efficiently through the
promulgation of standards of performance.
2. Adopting national standards of performance would be
more compatible with .existing state regulations than
adopting ambient air quality standards.
3. Since accumulation of fluorides during chronic exposure
to low-level ambient concentrations may result in
fluoride levels detrimental to either vegetation or to
the health of animals consuming the vegetation, an
ambient standard for fluorides may not in fact ensure
prevention of adverse welfare effects.
4. An ambient fluoride standard stringent enough to ensure
complete protection against any welfare effects might
require closure of major sources of fluoride emissions.
A more practical and feasible approach is to minimize
fluoride damage through best demonstrated control
technology; i.e., by regulating fluoride emissions
under section 111.
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5. The National Academy of Sciences report indicates that
because fluorides present no direct hazard to human
health, the provisions,of section 112 for controlling
fluorides as a hazardous air pollutant could not be used.
Promulgation of the proposed standards of performance for
fluorides will affect existing sources as explained in section F
of this preface. Of particular note is that states will be
required to establish standards for the control of fluorides
from existing sources under section lll(d) of the Act. The
resulting control may not be as stringent as that required by
the standards of performance for new sources. As indicated
previously, regulations,prescribing procedures for control of
existing sources under section lll(d) will be proposed as Subpart
B of 40 CFR Part 60.
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TABLE OF CONTENTS \
Page
Introduction 1
Selection of Affected Facilities 1
Selection of Pollutants for Control 5
Selection of Units for the Standards ' 6
Selection of Sampling and Analytical Methods 9
Selection of Facilities for Source Tests 10
Wet-Process Phosphoric Acid Plants .... , 19
Summary of Proposed Standard 19
Description of Process 20
Emissions and Methods of Control . 22
Rationale for Proposed Standard . -...-.<.... 24
Superphosphoric Acid Plants. . ..-. . . -: . ...... > .... 27
Summary of Proposed Standard . V ...... 27
Description of Process 27
Emissions and Methods of Control ..... 30
Rationale for Proposed Standard ... 30
Diammonium Phosphate Plants 37
Summary of Proposed Standards ......... 37
Description of Process . 38
Emissions and Methods of Control 38
Rationale for Proposed Standard 40
Run-of-Pile Triple Superphosphate Plants 45
Summary of Proposed Standards 45
Description of Process. ...:......, 46
Emissions and Methods of Control 46
Rationale for Proposed Standard .... 48
Granular Triple Superphosphate Plants. . . 53
Summary of Proposed Standards 53
Description of Process 54
Emissions and Methods of Control 54
Rationale for Proposed Standard 56
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Page
Granular Triple Superphosphate Storage. 61
Summary of Proposed Standards 61
Description of Process 61
Emissions and Methods of Control 53
Rationale for Proposed Standard 65
References , .t . 69
Appendix A - The Economic Impact of Standards of
Performance on the Phosphate
Fertilizer Industry. ............." 73
Technical Report Data Sheet ......... i -. ...... 119
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BACKGROUND INFORMATION FOR PROPOSED STANDARDS OF PERFORMANCE:
PHOSPHATE FERTILIZER INDUSTRY
INTRODUCTION
Selection of Affected Facilities
The phosphate fertilizer industry is totally dependent on phosphate
rock as its major raw material. About fifteen .major processes are
used to process phosphate rock into fertilizers and other -products.
Six of the major processes have been selected for the current program.-
Others are planned for inclusion in future programs.
Figure 1 shows the large number of fertilizer products and chemicals
produced from phosphate rock. After preparation, the rock is used
directly in the production of phosphoric acid, normal superphosphate-,
triple superphosphate, nitrophosphate, electric furnace phosphorus'and
defluorinated animal feed supplements. Phosphoric acid is an intermediate
material, since it is subsequently consumed in the production of
superphosphates, ammonium phosphates, complex fertilizers, superphosphoric
acid and dicalcium phosphate.
EPA has conducted an extensive study of the industry, including a testing
program to develop standards of performance for emissions from the
following facilities, which are areas of major growth or are major sources
of emissions.
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FIGURE 1
PHOSPHATE ROCK PROCESSING INDUSTRY
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1. Wet-process phosphoric acid
2. Superphosphoric acid
3. Diammonium phosphate
4. Run-of-pile triple superphosphate (production and storage)
5. Granular triple superphosphate production
6. Granular triple superphosphate storage
These processes are indicated by the shaded buildings shown in Figure 1.
In selecting the six areas for which standards were to be developed,
primary considerations were the growth potential of each process and the
environmental impact of a standard. Recent articles in the literature
indicate that production by these processes will increase by as much as
234
20 percent over the next 2 years. ' Table 1 shows projected growth
for wet-process phosphoric acid, ammonium phosphates, and triple
superphosphates of about 70, 90, and 20 percent, respectively, over the
decade of the seventies. The environmental impact of these processes is
significant as evidenced by the estimated fluoride emissions shown.
Superphosphoric acid was selected because of its tremendous growth potential
(150 percent between 1970 and 1980), even though its collective environmental
impact is not estimated to be as great as that of some of the other processes.
A potential source of large quantities of gaseous fluoride emissions is ponds
used as cooling and settling basins for process waters. Water from these
basins, commonly called gypsum ponds, is used to scrub fluorides out of
exit-gas streams from each phosphate fertilizer process. The fluoride
content of this gypsum pond water ranges from 5,000 to 10,000 parts per million,
and the pond itself appears to be a major source of fluoride emissions.
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Approximations of these emissions range from 0.16 to 5.0 pounds per acre per
day,9'10 which for a typical 200 acre, pond Is 32 to 1QQO pounds of fluoride per
day. There is no suitable technique to measure fluoride emissions from
gypsum ponds, but the Environmental Protection Agency is now funding a
research project at North Carolina State University to study emissions from
these ponds. This background information may permit preparation of
performance standards for gypsum ponds at a later date.
Selection of Pollutants for Control
In assessing the environmental impact of each of the processes for which
standards are now being proposed, the quantity and toxicity of emitted
pollutants were considered. Laboratory analyses performed on samples of
feedstocks, products, byproducts, and scrubbing liquid did not indicate
significant amounts of heavy metals such as mercury, beryllium, cadmium,
arsenic, etc. However, significant quantities of fluoride were found in
all of the samples. Documented evidence shows that fluorides emitted by
phosphate fertilizer plants are responsible for damage to commercially grown
flowers, fruits, and vegetables.5'6'7'23'24 Low concentrations of fluorides
can also be absorbed by grasses and plants and cause fluorosis in animals
feeding upon such forage. This disease causes mottling of teeth, affects bone
5 7 23 24
structure, retards growth, and adversely affects general health. ' ' '
Fluoride is emitted from phosphate fertilizer processes as colorless,
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gaseous silicon tetrafluoride (SIF^) and hydrogen fluoride (HF). Also,
because of the residual fluoride in the recycled water stream which is used
as the scrubbing medium, any mist entrained in the scrubber exhaust would
contain fluorides. Essentially all of the fluoride emissions were found
-------
to be water-soluble. For this reason, it was originally considered to
establish performance standards for water-soluble fluorides only. However,
during the National Air Pollution Control Techniques Advisory Committee
(NAPCTAC) meeting in February 1973, fluoride standards were discussed for two
industrial categories, primary aluminum and phosphate fertilizer. A change
from water soluble to total fluorides was recommended by a representative for
the primary aluminum industry. He revealed that some "insoluble" fluoride
compounds will slowly dissolve if allowed to remain in the water-tmpinger
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section of the sample train. Since EPA had not closely controlled the time
between capture and filtration of the fluoride samples, the change to total
fluorides was, made to assure a more accurate data base. Since recalculation
on the basis of total fluorides revealed that 80 percent of the data remained
unchanged and the greatest change was only three percent, it was not necessary
to change the absolute value of the proposed standards.
Selection of Units for the Standards
Units of both concentration and mass were considered for the standard.
Concentration units have the advantage of being simple and easy to enforce,
and they are a parameter used in the design of air pollution control
systems. However, they do not necessarily indicate efficient control of
mass emissions for this industry. For a given concentration in the
effluent gas stream from a control system, the quantity of emissions will vary
directly with the effluent gas volume. Our data revealed that even within
the same process, the gas volumes vary significantly. For wet-process
phosphoric acid plants, gas volumes from plants producing 375 and 325 tons
P20g per day varied from 47,500 to 295,000 standard cubic feet per ton of
PO,-, respectively.
-------
A mass standard will encourage industry to minimize the amount of process air
used, which could further reduce fluoride emissions. A drawback is that '
many plants do not weigh the fertilizer product; they do, however,.determine
quite accurately the weights of raw materials and the P^O,- content of the
feedstock. Therefore, the best units for the performance standard are
"pounds of fluoride per ton of P?0,- fed." The same units are used by
a State agency for its phosphate fertilizer emission control regulations.
Because water absorption of fluorides is the common control mechanism, the
possibility of a single fluoride emission standard was considered for all
processes in the industry. This approach, however, proved impractical.
The great variation of fluoride concentrations and gas volumes from each
process precludes the selection of a single standard that would represent
"best demonstrated control" for all processes. Table 2 shows some of the
major differences in emissions from the six processes. Although the
final concentration of fluorides is about the same for most of the
processes, the volume of emissions varies greatly, not only from process
to process but also for the same process operated by different owners.
Consequently, the mass emission rates measured as pounds of fluoride per
ton of P205 vary by a fac'tor of 1,000. Obviously, a single performance
standard for all processes based on either mass or concentration of
fluoride in the emissions would be unsuitable.
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During preliminary plant inspections of each of the six processes, some
plants of each type had visible emissions of less than 10 percent opacity.
A scrubber that effectively controls gaseous fluorides appears to effectively
control particulate fluorides also. Therefore, a separate performance
standard for particulates was felt to be unnecessary.
Particularly characteristic of this industry are the interrelationships
between air pollution and potential water pollution. Also, solid waste
and water pollution problems can be encountered with the production of
wet-process phosphoric acid, an intermediate product. Filtered crystals
of gypsum, a byproduct, along with impurities such as fluorides, cilcium,
iron, aluminum, and magnesium compounds, are slurried and pumped to nearby
gypsum ponds. The water is continuously recycled both for process use
and as the scrubbing medium for the control devices. When heavy
rainfall causes the pond to overflow, the overflow is treated with lime
to raise the pH to acceptable levels and precipitate fluorides before it is
discharged to a receiving body of water.
Selection of Sampling and Analytical Methods
An EPA sampling train was developed to measure fluoride emissions. Samples obtained
from the 2-hour isokinetic samples were filtered in the. laboratory to permit
-------
water-soluble and water-insoluble fluorides to be determined separately.
The water-soluble portions were analyzed with the specific ion electrode.
The water-insoluble portions were fused with sodium, distilled with sulfuric
acid, and then analyzed by the SPADNS-Zirconium Lake Method.
Results of EPA tests generally compared favorably with emission measurements
conducted by the owner or operator. Although no single explanation for
isolated differences was evident, some of the differences could be due to
variations in sampling techniques employed by operators of the various plants
that were tested. These operators use a less sophisticated sampling
technique than EPA. Their sampling train has no ice bath and the operators
sample at the point of average velocity, rather than traversing and sampling
isokinetically as required by the EPA procedure. Analytical techniques have
been verified by comparative tests. Most EPA and industry results agreed
within 10 percent. However, substantially lower values were reported by a
State agency (see Table 3).
Selection of Facilities for Source Tests
The phosphate fertilizer industry uses water scrubbers to remove fluoride
from their emissions. Figures 2, 3, 4, and 5 show the types of scrubbers
1811
commonly installed for air pollution abatement in this industry. ปฐป11
The efficiency of these scrubbers is difficult to ascertain without a source
test because there is no known device that continuously monitors gaseous
fluorides or particulates in this industry. Since gaseous fluorides are
invisible, it is impossible by visual observations to directly judge the
effectiveness of the control system for fluoride removal. Particulate
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emissions can often be estimated by sight observations, and the presence
of excessive visible emissions is an indication of poor performance for both
participates and fluorides. The best indicators of efficiency or
performance available to the plant operator are scrubber pump discharge
pressure and pressure differential through the control device.
The initial screening of best-controlled plants was based on:
1. Emission data submitted by manufacturers,
2. Emission data submitted by States,
3. Recommendations by The Fertilizer Institute, and
4. Conversations with industry representatives.
Over 50 plants in eight States were inspected in this program. During
investigation of various plant control devices, we were limited by the same
problems as the operator -- inability to appraise control efficiency without
a source test. Consequently, best-controlled plants were selected according
to the type of control device used, its operating characteristics, and
apparent quality of maintenance.
Very few processes employed the best emission control systems. Some that did
were not suitable for emission testing, and the data base for the recommended
performance standard for each affected facility is thus limited. In all
processes, however, control is achieved by removal of fluorides from air
with water, an extremely good solvent for fluorides. Fluoride removal
by a water medium is thus common to the family of processes and this permits
a broader base for the application of engineering judgment than individual
consideration of each process alone.
12
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Although only a limited number of affected facilities were sufficiently
well controlled to warrant testing, most of those selected used a packed
scrubber with the scrubbing liquid sprayed on the packing perpendicular to
the direction of gas flow (Figure 2). They had consistently high
control efficiencies. The packed scrubber, which appears to represent
best demonstrated control technology, can be used by all affected facilities.
Other types of scrubbers used by the industry are shown in Figures 3, 4 and
5. Although fluoride emissions from these were higher than from the
packed scrubber, there appears, to be no reason why similar levels of
control cannot be achieved by these types.
During the test program for the development of standards, the following
criteria were used in conducting emission tests of each process:
1. The plant was operating at or above its design rate.
2. The scrubbers appeared to be properly maintained.
3. Where possible, plants were tested which'use phosphate rock
from different rock deposits.
4. In some cases, emission measurements were conducted on the
same scrubbers during summer and winter to determine if scrubber
performance changed appreciably.
5. When possible, emission measurements were conducted during process
operating conditions that would generate the highest rate of
emissions of fluorides.
By employing these five criteria, emission measurements from comparatively few
"best-controlled" plants provide a firm data base for the development of
performance standards.
13
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CONTAMINATED
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Figure 4. Air-induced venturi scrubber.
16
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17
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WET-PROCESS PHOSPHORIC ACID PLANTS
SUMMARY OF PROPOSED STANDARD
A standard of performance is being'proposed for new wet-process-
phosphoric acid (WPPA) plants. The proposed standard would limit emissions
of total fluorides from the wet-process phosphoric acid plant, which
is the affected facility. Major sources include but are not limited to
the reactor, filter, filtrate seal tanks, barometric condenserTiotwells,'
fluosilicic acid tanks, and clarifier tanks. The standard applies at the
point(s) where emissions are discharged from the afr pollution control
system or from the affected facility if no air pollution control system
is utilized.
The proposed standard would limit emissions to the atmosphere as ,
follows:
Total Fluorides
No more than 10 grams of total fluoride per metric ton of P20g input to
the process (O.OZ pounds per ton).
19
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DESCRIPTION OF PROCESS
The basic reaction is the acidulation of tricalcium phosphate in the
phosphate rock. Phosphate rock, sulfuric acid, and water react to
produce phosphoric acid and calcium sulfate dihydrate (gypsum).
simplified reaction is:
13
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The production of wet-process phosphoric acid (WPPA) is depicted in the
flow diagram shown in Figure 6. The process consists of a reaction step
(where rock is acidulated to form phosphoric acid), a filtration step
(where the solids are separated from the acid), and an evaporation step
(where the acid is concentrated). At the beginning of the process,
measured quantities of 93-percent sulfuric acid, weak phosphoric acid
(from the filter cake washing process), and pulverized phosphate rock
are introduced into a reactor. The highly exothermic reaction is cooled
by a vacuum cooler, which also degasifies the slurry of dissolved air,
carbon dioxide, and fluorides. After a retention time of 5 to 8 hours,
the slurry is pumped to a filter where the acid is separated from the
byproduct gypsum. -The gypsum is reslurried with effluent process water
amd pumped to the gypsum pond. The acid, containing about 30-percent
P205, is concentrated by vacuum -evaporators to about 54-percent
The 54-percent ?2ฎ5 aci'd is then pumped to product storage tanks.
Some plants recover fluorides as byproduct fluosilicic acid by installing
absorption sections on the top of the evaporators immediately upstream
from the barometric condensers. '
20
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EMISSIONS AND METHODS OF CONTROL
Gaseous fluorides evolve from any /luoride-containing liquid because of the
vapor pressure of the fluoride. The rate of evolution varies with
temperature, concentration, absolute pressure, and exposed area of the
liquid surface.
Some poorly controlled WPPA plants can emit 0.07 pound of fluoride per
ton of P205 input. A 500-ton-per-day (TPD) P20g installation, equipped
with such control equipment would emit 35 pounds of fluorides each day of
operation. Well-controlled plants which use packed scrubbers or other
equally effective control can achieve fluoride emissions below 0.02 pound
fluoride per ton of P^Og input (see Figure 7). Such a well -control led
500-TPD P20g plant would- emit 10 pounds of fluoride per day,
Best demonstrated emission control consists of scrubbing off-gases. with
pond water in a packed scrubber. These typically achieve 98 to 99 percent
removal of fluorides.
Several State and local regulations limit fluoride emissions from wet-
process phosphoric acid plants. Some regulations restrict the mass of
emissions per unit of production. Others are based on the fluoride content
of surrounding vegetation or ambient air concentrations. The most ,
stringent State regulation, 0.02 pound fluoride per ton of P205 feed to the
process, would permit the typical 500-TPD PpO plant to emit 10 pounds of
fluoride per day.
22
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RATIONALE FOR PROPOSED STANDARD
Selection of Pollutants for Control
Fluoride is the only significant air pollutant emitted from WPPA plants.
Discussion
Preliminary investigation revealed the location of several reportedly
well-controlled plants. Twelve were visited and information was obtained
on the process and control equipment. Seven were not further considered
for testing because fluoride fumes were excessive in the processing
area (perhaps the result of inadequate maintenance) or the physical
arrangement of the equipment (e.g., ductwork configuration) was not
suitable for accurate testing. Stack tests were conducted at the remaining
five locations. One of these was-later tested a second time to see if
seasonal variations had any effect on emissions. Results of that test
showed higher emissions during warm weather, indicating a possible effect
of i.the temperature of gypsum pond water on the effectiveness of the control
device. However, similar seasonal tests of emissions from superphosphoric
acid and diammonium phosphate plants failed to confirm such an effect.
During the initial plant surveys, 12 plants with scrubbers exhibited no
visible stack emissions other than uncombined water vapor. Results of one
test on Plant A, which measured 0.065 Ib/ton of P205, were not considered
-------
during the final evaluation of the data.- This figure was unexplainably much
higher, not only than any other EPA sample, but also much higher than any results
the operator had measured from numerous tests over the previous year. No definite
reason for the high number could be identified. The process instrumentation
gave no indication of a process upset or scrubber malfunction. Results of the
other two samples were 0.011 and 0.019 pound fluoride per ton P205 input. Results
of testing by the operator indicated average fluoride emissions of 0.013 pound
fluoride with a range of 0.007 to 0.018 pound fluoride per ton p205 input.
Results of the tests conducted by EPA reveal emissions from plants with packed
scrubbers (Plants A, B, C, and E) averaged 0.015, 0.006, 0.002, 0.012 (retest of
Plant C), and 0.011 pound fluoride per ton of p205 input. Plant D, controlled
by an impingement scrubber, averaged 0.008 while ranging from 0.006 to 0.011;
however on the average, impingement scrubbers do not perform as well as packed
scrubbers for this process.
Concurrent testing by the plant operator indicated average fluoride emissions
of 0.014 (Plant B)-'and 0.010 (Plant. C) pound fluoride per ton P205 input.
Individual samples ranged from 0.010 to 0.017 pound.
Tests were conducted by EPA while the plants were operating at or near their
' design" production rates. A complete summary of test results .can be found in
Volume 2.
The proposed standard of 10 grams of total fluoride per metric ton of
P.-.Oj. input (0.02 pound per ton) is supported by emissions measured from the
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plants as presented in Figure 7. The standard will require installation and
proper maintenance of equipment representative of the best technology
which has been demonstrated for the industry. In the Administrator's
judgment, achievability of the proposed standard of 10 grams of total fluoride
per metric ton (0.02 Ib F/ton P2ฐ5) nas been adequately demonstrated.
25
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A visible emissions standard is not recommended for WPPA plants. Since there
can be no emissions visible even from an uncontrolled WPPA plant, a standard
would have little meaning.
26
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SUPERPHOSPHORIC ACID PLANTS
SUMMARY OF PROPOSED STANDARDS
A standard of performance is being proposed for new superphosphoric acid (SPA)
plants that manufacture acid-for the production of fertilizer. The proposed
standard would limit emissions of total fluorides from the superphosphoric
acid plant, which is the affected facility. Major sources include but are not
limited to evaporators, product cooling tanks, and barometric condenser hotwells.
The standard applies at the point(s)'where emissions are discharged from the air
pollution control system or>from the affected facility if no air pollution control
system is utilized. The proposed standard would limit emissions to the atmosphere
as follows:
Total Fluorides
No more than 5 grams of total fluorides per ton of P^Or input to the process
(1 x 10"2 Ib/ton).
DESCRIPTION OF PROCESS
SPA is produced by concentrating 54-percent P?0r phosphoric acid to 70 (+2)*
.percent P90[-. Two commercial processes are used for SPA: vacuum evaporation
*' . .ฃ O **-..--
(VE) and submerged combustion (SC).
Production of SPA by vacuum evaporation (VE-SPA) is. depicted in Figure 8. Clarified
54-percent P205 phosphoric acid is continuously fed to a vacuum evaporator. The
hot off-gases, which contain water vapor and fluorides, are condensed in the
water-cooled barometric .condenser. The fluoride-laden condenser water flows to
the hotwell where it cools before draining to the gypsum pond. The concentrated
acid is continuously drawn from the evaporator to product cooling tanks, where
it is cooled before being pumped to storage.
In the submerged combustion (SC-SPA) process, depicted in Figure 9, hot gases are
forced below the surface of the 54-percent PpOj- phosphoric acid in a submerged
27
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combustion evaporator. Water vapor, fluorides, and phosphoric acid mist are
driven from the solution, and concentrated acid is drawn off as product. Fluorides
13 19
and phosphoric acid mist generated by this process are difficult to control. '
EMISSIONS AND METHODS OF CONTROL
Uncontrolled SC-SPA plants can release as much as 22 pounds of fluorides per ton of
P00C.18 An uncontrolled 200-TPD installation would emit 185 pounds of fluoride
d 5 , .
each hour of operation.
In addition to the absence of combustion products and their dilution effect, a
second advantage of the VE-SPA system is that fluorides are absorbed by water
in the barometric condenser during normal operation of the process. This sig-
nificantly reduces the quantity of fluorides which must be controlled by the
13 18 19
emission control device. ' '
No State or local regulation specifically limits fluoride emissions from SPA
plants. However, one State requires that any source of fluorides (i.e., SPA
plants) not specifically regulated by the State will'be controlled in accordance
with "latest available technology."
RATIONALE FOR PROPOSED STANDARD
Selection of Pollutants for Control
The potential pollutants from SPA plants are phosphoric acid mist, sulfur
oxides, combustion products, and fluorides. Manufacturers of SPA normally
control phosphoric acid mist to increase product yield. The equipment necessary
to control fluorides to the limits proposed by the standards will also provide
some control for any phosphoric acid mist, sulfur oxides, and combustion products
not now controlled. Therefore, only fluorides were considered for standards
development.
30
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Discussion
No SC-SPA plants were tested bv-EPA in the development of the
proposed standards for several reasons: 1) no well-controlled
plants were observed; 2) the majority of members of the phosphate
fertilizer industry consider submerged combustion an outdated process and
future growth unlikely; and 3) the Act makes clear that new plants should
utilize processes which have the least environmental impact.
Two seemingly well-controlled VE-SPA plants were located.
One produces a specialized SPA used as an intermediate for the production
of animal feed. This process is designed to steam-strip fluorides from
the acid to minimize the possible effect on'animals that consume the feed.
As might be expected, this results in high evolution of fluorides from
the process. The average for the test by EPA was 0.02 Ib F/ton of P20g
input with a range of 0.015 to 0.024. This average is 20 to 40 times
greater than that measured from a similar plant which produces SPA as an
intermediate for the fertilizer industry and consequently does not purposely
strip fluorides. Because the process associated with animal feed is
distinctly different from the majority of SPA plants which produce an
intermediate for the fertilizer industry, it was decided to recommend
that the standard not apply to those facilities that prepare animal feed.
(In the event a single plant manufactures for both markets, it will be
subject to the standard when producing a fertilizer intermediate.) Consequently,
the data from this first plant test were not used in the development of the
performance standard.
31
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The second well-controlled plant, which does produce SPA for the fertilizer
industry, was tested by EPA in the early winter of 1971 and again in the
summer of 1972.
Results of the two tests (three samples per test) conducted by EPA (Figure 10).
reveal emissions from Plant A average 9 x 10" and 4.6 x 10" pound of
fluoride per ton of P205 respectively. Individual sample results ranged from
4.1 x 10"4 to 15 x 10"4 Ib F/ton P205.
Tests were conducted by EPA while the plant was operating at or near its design
production rate. A complete summary of test results can be found in Volume 2.
During the initial plant surveys, none of the VE-SPA plants exhibited visible
stack emissions other than uncombined water vapor.
Based on the emission test data from the VE-SPA plants, EPA originally
considered proposing a standard of 1 gram of fluoride per metric ton of f
P90,- input (2 x 10"3 Ib/ton). The inherently low uncontrolled emissions
c, o
from this process made it obvious that the SC-SPA process could not be economically
controlled to the same level. This would probably preclude any future con-
struction of the SC-SPA process and, at that time this action seemed justifiable
since inherent characteristics of the SC-SPA process render it significantly
more polluting than the VE-SPA process. Furthermore, as stated previously,
representatives of the industry indicated that the SC-SPA process was near
obsolete and would not be built regardless of any subsequent air pollution
standard. When the standard was presented at the National Air Pollution
Control Techniques Advisory Committee (NAPCTAC) meeting, it became obvious that
two companies consider the SC-SPA process the more desirable. In fact, they
32
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contend that the decreasing quality of the nation's phosphate rock reserves
coupled with the inability of the VE-SPA plant to use acid from poor quality
rock make it essential for the SC-SPA process to remain a viable option for
future plants. They maintain that a standard which permits the SC-SPA process
is in the best interest of our national resources.
In altering the standard to permit the SC-SPA process, the result is that
VE-SPA plants will not be required to install a control device. Separate
standards for VE-SPA and SC-SPA plants were considered. This alternative has
little merit. The original objective of the fluoride standard was to indirectly
force prospective SPA plant operators to construct the VE-SPA process, not to
reduce fluoride emissions from VE-SPA plants (which are only about four pounds
per day). The standard now recommended is sufficiently stringent to still
-------
a. The average fluoride concentration measured by EPA. from packed
scrubbers controlling wet-process phosphoric acid plants, diammonium
phosphate plants, granular triple superphosphate plants and granular
triple superphosphate storage buildings was three ppm.
b. One designer of a packed scrubber reported that an exit concentration
of three ppm fluorides can always be achieved and that they are designed
to achieve 1.5-2 ppm.
Data supplied by a major operator of an SO-SPA plant indicate that gases
exit his plant at a rate of 47,000 standard cubic feet per ton of P205- The
exit concentration of 11,000 ppm by volume is reduced to 50 ppm with the
existing control system.
To verify the practicality of a standard which is essentially equivalent
to 3 ppm (although higher concentrations are pernrissable if the volume of
exhaust gas is reduced), conventional design criteria were used to estimate
the efficiency (measured in terms of transfer units) which would be required
of a control device.
The number of transfer units necessary to achieve three ppm was calculated
as follows. The calculation assumes that the concentration of fluorine in the
scrubbing liquid is constant through the scrubber, a valid assumption because
of its relatively high concentration in the inlet liquid. The number of transfer
Q
units required to scrub a lean gaseous effluent is defined by:
NOG,= 1n
Yl -
Where:
rtr
Ufa
= number of transfer units
Y, = fluoride concentration in the inlet gas phase (.11,000 ppm)
35
-------
Y2 = fluoride concentration in the outlet.gas phase (3 ppm)
Ya = fluoride concentration in the gas phase in equilibrium with the
scrubbing liquor (1.5 ppm, based on equilibrium vapor pressure
pr p/r
data for gypsum pond water) and other sources.
Using these criteria, NOS is calculated as 8.9 transfer units. If a
packed scrubber is installed downstream of an existing control device which
achieves 50 ppm, then only 3.5 transfer units are required of the packed
scrubber.
Packed scrubbers now operating at other phosphate fertilizer processes
commonly achieve three to four transfer units. Therefore, a scrubber of about
the same efficiency would be needed to supplement typical existing control at
SC-SPA plants.
It is possible that other acid gases such as SOX may adversely influence
the absorption efficiency and require slightly more transfer units than the
above calculations would indicate. Also, the presence of acid mists may require
the installation of a mist eliminator or some other partlculate collection device,
such as a venturi scrubber. Even if this additional control is needed, the cost
of control is not prohibitive (0.13 percent of the sales price of SPA as
reported in the economic report following the technical reports) and in the
Administrator's judgment, the achievability of the proposed standard has been
adequately demonstrated.
Since no existing SC-SPA plant now operating has a control device which
can be considered best technology, we are unable to obtain visible emission
data. Consequently, no visibility standard will be recommended at this time
for the SPA process.
36
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DIAMMONIUM PHOSPHATE PLANTS
SUMMARY OF PROPOSED STANDARDS
Standards of performance are being proposed for new diammonium phosphate
(DAP) plants. The proposed standards would limit emissions of total
fluorides and visible emissions from the diammonium phosphate plant, which
is the affected facility. Major sources include but are not limited to
the reactor, granulator, dryer, cooler, screens, and mills. The standards
apply at the point(s) where emissions are discharged from the air pollution
control system or from the affected facility if no air pollution control
system is utilized.
The proposed standards would limit emissions to the atmosphere as follows:
Total Fluorides
No more than 30 grams fluoride per metric ton of PgOg input to the process for
new diammonium phosphate plants (0.06 pound per ton).
Visible Emissions
Visible emissions shall be less than 20 percent opacity.
37
-------
DESCRIPTION OF PROCESS
The process consists of a prereactor, a reactor-granulator, and accessory
19
equipment for drying, cooling, and screening the product (Figure 11).
The primary reaction is: 2 NH3 + H3P04 > (NH4)2 HP04.
Unreacted ammonia gas which is not absorbed by the rock is carried from
the prereactor and granulator with the exhaust gas. Most of the ammonia
is recovered by scrubbing the exhaust gas with a weak (20 to 30 percent
PgOg) phosphoric acid solution.
The DAP slurry in the reactor is pumped to the granulator where additional
ammonia and recycled product are added to form a solid material which
averages 18 percent nitrogen and 46 percent Pg^- ** 1S then driedป cooled,
and screened before being conveyed to storage.
EMISSIONS AND METHODS OF CONTROL
Considerable quantities of fluorides can be stripped from the scrubbing
medium, dilute phosphoric acid which contains fluorides. This source of
fluorides is particularly significant when a higher concentration acid
(30 to 40 percent Pg^) ^s use(*. Fluorides are also present in any
mist entrained from the scrubbers or in solid particulates carried from
both the granulator and dryer.
J ' ' r '
Poorly controlled diammonium phosphate plants can release up to 0.5
pound of fluoride to the atmosphere per ton of-PgOg input. A 500-TPD
38
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P205 installation, equipped with such control equipment, would emit
250 pounds of fluorides each day of operation. Well-controlled
DAP plants employing primary and secondary scrubbers can achieve fluoride
emissions below 0.06 Ib F/ton PgOg input or 30 pounds of fluoride per day
(see Figure 12).
Although ammonia is a potential pollutant from diammonium phosphate plants,
the industry has long maintained good control of ammonia, a major raw
material, because of its relatively high cost.
The best demonstrated control for ammonia consists of scrubbing emissions
with a weak phosphoric acid solution. Fluorides are removed by
secondary scrubbing with packed scrubbers.
Several State and local regulations limit fluoride emissions from
diammonium phosphate plants. Some restrict the mass of emissions per
unit of production. Others are based on the fluoride content of surrounding
vegetation or ambient air concentrations. The most stringent State
regulation, 0.06 pound fluoride per ton of PgOg feed to the process,
would permit the typical 500-TPD P205 plant to emit 30 pounds of fluoride
per day.
RATIONALE FOR PROPOSED STANDARDS
Selection of Pollutants for Control
Ammonia, fluorides, and particulates are potential pollutants from this
process. The low concentrations of ammonia measured during this program
(1 ppm) verified that operators are very effectively recovering ammonia.
-------
Combustion products from the drying operation are present in the stack
gases, but in very minor concentrations. Therefore, only fluorides and
particulates were considered for standards development.
Discussion
Preliminary investigations revealed the locations of several reportedly well-
controlled plants. Nine were visited and information was obtained on the process
and control equipment. Six were not further considered for testing because
either fluoride fumes were excessive in the processing area (perhaps the result
of inadequate maintenance) or the equipment (e.g., ductwork configuration)
was not suitable for accurate testing. One of these (Plant B) was modified to
accommodate an EPA test in March of 1973. Stack tests were conducted at the
remaining locations. Plant A was tested twice.
During the initial plant surveys, 9 plants with scrubbers exhibited no
visible stack emissions other than uncombined water vapor.
Emission measurements at Plant A were conducted by EPA during different
seasons. The two tests yielded average results of 0.040 and 0.028 Ib F/ton
P205, respectively, as shown in Figure 12. During the first EPA test the
operator tested his plant using a different test method. His results indicated
an average emission of 0.034 Ib F/ton P00,-.
ฃ b
EPA emission measurements at Plant B yielded average results of 0.039 Ib F/ton
P2ฐ5' The operator of Plant B has reported average fluoride emissions of 0.041
pound per ton of P2ฐ5- This average is based on 23 emission tests during a
12-month period. Some of the higher results vary enough from the mean
41
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to question their validity as part of the total sample population with
99-percent confidence. However, they have been included in Figure 12.
Plant C was tested by EPA to estimate an emission factor for DAP plants
as part of an industrial study which preceded the program for developing
standards. Plant C compromises fluoride control. Rather than install
a separate water scrubber to control fluorides, they use a weak acid
(22 percent P2ฐ5) i" an attempt to recover ammonia, particulates, and
fluorides in a single scrubber. Data from Plant C were not considered in
the development of a recommended new source performance standard for DAP
plants.
-All tests were conducted by EPA while the plants were operating at or near the
design production rate. A complete summary of test data for Plants A and B
can be found in Volume 2. Since Plant C was tested under another study, the
test data from that plant are not presented in Volume 2 but may be obtained
fmm thp Fmission Standards and Engineering Division.
The proposed standard of 30 grams of fluoride per metric ton
of P20g input (0.06 pound per ton) .is supported by emissions measured by EPA
from Plant A and Plant B as presented in Figure 12. This standard will
require installation and proper maintenance of equipment representative of the,
best technology which has been demonstrated for the industry. In the
Administrator's judgment, the achievability of the proposed standards has been
adequately demonstrated.
The proposed visible emission standard of 20. percent is based on data obtained
in February 1974. Visible emissions were read simultaneously by two qualified
observers during a valid one-hour test. Other data collected at the DAP plant
were not considered representative due to problems with the control equipment
during part of the test and because during another portion, the plant was
forced to reduce its production below normal due to operational problems.
43
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-------
RUN-OF-PILE TRIPLE SUPERPHOSPHATE
PLANTS
SUMMARY OF PROPOSED STANDARDS
Standards of performance are being proposed for new run-of-pile triple
superphosphate (ROP^TSP) production plants and ROP-TSP storage piles.
The proposed standards would limit emissions of total fluorides
from the run-of-pile triple superphosphate plant (including the storage .
building(s)), which is the affected facility. Major sources include but are
not limited to the TVA cone mixer, curing belt (den), transfer conveyors,
and storage piles. The standards apply at the point(s) where emissions '
are discharged from the air pollution control system or from the affected
facility if no air pollution control system is utilized. The same standards
are being proposed for granular triple superphosphate plants and will be
discussed for such plants in a separate section.
.'otal Fluorides
No more than 100 grams of total fluoride per metric ton of P00r input
25 K
(0.20 pound per ton).
Visible Emissions
Visible emissions shall be less than 20 percent opacity.
-------
DESCRIPTION OF PROCESS
Measured quantities of ground rock and 54-percent P205 phosphoric acid
are combined in a mixer (Figure 13). The resultant viscous slurry
drops onto a slowly moving belt (or den) where it solidifies. When the
porous mass reaches the end of the belt, it is reduced to small chunks by
a cutter. The ROP-TSP is then conveyed to a storage pile where the
reaction continues. After approximately 30 days the reaction is complete,
and the product is considered "cured" and ready for shipment.
EMISSIONS AND METHODS OF CONTROL
Emissions of fluorides and particulates occur during the production,
conveying, and storage of ROP-TSP. Emissions from storage are greater
during periods when the pile is being rearranged than when it has lain
undisturbed for an extended period.
Uncontrolled ROP-TSP plants can release 1 pound of fluoride per ton of
I Q
PgOs. A typical uncontrolled 600-TPD installation would emit 600
pounds of fluoride each day of operation.
The best demonstrated control of fluoride consists of scrubbing emissions
with water. No visible emissions were observed from storage facilities
with this type of control. This verifies good control of particulate
emissions.
Several State and local regulations limit fluoride emissions from ROP-TSP
plants. Some restrict the mass of emissions per unit of production.
-------
47
-------
Others are based on the fluoride content of surrounding vegetation or
ambient air concentrations.1 The most stringent State regulation, 0.17
pound fluoride per ton of P205 input,17 would permit the typical 600-TPD
P205 plant to emit 102 pounds of fluoride per day. (This limitation,
however, is based on the analytical technique used by the State and
cannot be directly compared to the proposed standards of performance.)
RATIONALE FOR PROPOSED STANDARDS
Selection of Pollutants for Control
The major pollutants emitted from this process are fluorides and
particulate matter. Reasons for the decision to require control of only
fluorides are presented in the Introduction.
Selection of Units for the Standard
Considerable attention was devoted to the selection of units for ROP-TSP
standards. Initially, separate standards were considered for ROP-TSP
manufacture and ROP-TSP storage since emissions from one of the major
sources, the storage pile, are independent of production rate. Most
manufacturers, however, have a single control system for the two sources
Therefore, this approach was not practical.
With a single control device, emissions from manufacture and storage
cannot be separately measured. Standards based on storage factors were
considered. However, emissions from a storage pile are dependent on
turnover, age, and quantity of ROP-TSP in storage. Incorporation of a
-------
"turnover" factor in the units of the standards was not considered
because of the extreme difficulty in quantifying and maintaining records
of this activity. Standards based on age of the product were briefly
considered because fresh ROP-TSP evolves more fluorides than cured ROP-TSP.
The units of such standards, however, would be cumbersome, and enforce-
ment would rely heavily on records kept by the manufacturer.
The final decision to orooose units of pounds of fluoride per
ton of P205 input to the process seemed most appropriate since 90 percent
of the total fluorides released from ROP-TSP are evolved during the
19
mixing, setting, and conveying steps and because total
the process is routinely measured.
input to
Discussion
22
Seven plants produce ROP-TSP in the United States. One does not control
fluorides from the storage pile. The remaining six were visited, visible
emissions were evaluated, and information was obtained on the process and
control equipment. Four were not further considered for testing because
emissions were excessive (perhaps the result of inadequate maintenance),
because the equipment (e.g., ductwork configuration) was not suitable
for accurate testing, or because a test could not be. scheduled (e.g.,
one plant only operated 3 to 6 weeks per year).
During the initial plant surveys, five plants with scrubbers exhibited
no visible stack emissions other than uncombined water vapor. Three of
these were not tested for reasons listed above.
49
-------
Results of the three tests conducted by EPA at two plants CFtgure 14) reveal
average emissions of 0.19, 0.21, and'0.12 pound of fluoride per ton of P205
input. Individual samples ranged from 0.03 to 0.31 pound of fluoride per
ton P205 input. Average results of similar tests by the operator of Plant
A over the previous year tend to support the averages obtained by EPA. The
average of 35 tests was 0.16 pound of fluoride per ton of P20g Input. Figure
14 also presents emission measurement data submitted by the operator of a
plant controlled by cyclonic scrubbers CPlant B). The measured emission rate
from this installation was 0.08 pound of fluoride per ton of P205 input. These
plant tests were not performed in accordance with EPA test procedures.
All tests were conducted by EPA while the plants were operating at or near
their dp^nn production rates.. A complete summary of test results can be
found in Volume 2.
The proposed standard of 100 grams of fluoride per metric ton of PZ05 input
(0.20 pound per ton) is supported by emissions measured from Plants A and B
as presented in Figure 14. This standard will require installation and
proper maintenance of equipment representative of the best technologywhich
has been demonstrated for the industry.
The Agency originally considered proposing a standard of 150 g F/metric ton
(0.3 Ib F/ton P2ฐ5) based on the actual emission tests of best-controlled
plants. However, like SC-SPA plants, ROP-TSP plants have not been fitted with
the more efficient control equipment typical of other phosphate fertilizer
processes. It is estimated that a packed scrubber could possibly limit
emissions to as low as 0.06 Ib F/ton P20g, based on a typical 400,000 scf/ton
effluent at three ppm exit concentration.
50
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The proposed visible emission standard of 20 percent is based on data
obtained in February 1974. Visible emissions were read simultaneously by
two qualified observers during two 2-hour tests. At one of the ROP-TSP
plants tested by EPA, one 15-second reading at 25 percent opacity and three
minutes of readings at 20 percent opacity were recorded in a 5-mfnute time
span during four hours of observation. No reason could be determined for
this short period of visible emission; however, the plant operator indicated
that the plant never has visible emissions except during upset conditions.
These unusual and inexplicable readings were not included in the data for
determining the opacity standard for ROP-TSP plants.
In the Administrator's judgment, the achievability of the proposed standard
has been adequately demonstrated.
52
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GRANULAR TRIPLE SUPERPHOSPHATE PLANTS
SUMMARY OF PROPOSED STANDARDS
Standards of performance are being proposed for new granular triple
superphosphate (GTSP) production plants. The proposed standard would
limit emissions of total fluorides from the granular trfple
superphosphate plant, which is the affected facility. Major sources
include but are not limited to the reactor, granulator, dryer, cooler,
screens, and mills. The standards apply at the point(s) where emissions
are discharged from the air pollution control system or from the affected
facility if no air pollution control system is utilized.
The proposed standards would limit emissions to the atmosphere as
fol1ows:
Total Fluorides
No more than 100 nraros of total fluoride ner metric ton of Pซ0r input
c o
to the process (0.20 pound per ton).
Visible Emissions
Visible emissions shall be less than 20 percent opacity.
53
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DESCRIPTION OF PROCESS
The direct-slurry process for production of granular triple superphosphate
begins with the reaction of phosphate rock and phosphoric acid. The
19 20
reaction proceeds as indicated: '
Ca3(P04)2 + 4 H3P04 + 3 H20 * 3[CaH4 (P04)2 . HgO]
A schematic diagram of the process is shown in Figure 15. The reactor slurry
is pumped to the granulator where it is mixed with undersize material from
the product screens. From the granulator, the granules flow to a rotary
drier. After drying, the 46 percent P20g product is cooled and screened
before being conveyed to the storage building.
In a somewhat similar process, granular triple superphosphate is also
produced by granulating cured run-of-pile triple superphosphate (ROP-TSP).
Such a plant does not require a prereactor, but all other facilities are
the same as those described for the direct-slurry granulation process. As
would be expected, emissions from plants processing cured ROP-TSP are much
lower than from the direct-slurry process since a significant portion of
the fluorides were evolved when the triple superphosphate was initially
manufactured in the run-of-pile form. Consequently, emission levels from
the GTSP plant using ROP-TSP as a raw material have not been investigated.
Plants which manufacture GTSP from cured ROP-TSP will not be subject to the
proposed standard.
EMISSIONS AND METHODS OF CONTROL
In addition to the gaseous forms, fluoride is emitted from granular triple
superphosphate plants in mists entrained from the scrubbers or in solid
particulates carried from both the granulator and dryer.
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Poorly controlled granular triple superphosphate plants can release up to
0.60 pound of fluoride per ton of P205 input.1 A 500-TPD P205 installation
with such control would emit 300 pounds of fluorides each day
of operation. Well-controlled GTSP plants can achieve fluoride emission levels
below 0 30 Ib F/ton P90, input or 150 pounds per day. The best demonstrated
11
control of fluoride consists of scrubbing off-gases with water.
Several State and local regulations limit fluoride emissions from
granular triple superphosphate plants. Some restrict the mass of emissions
per unit of production. Others are based on the fluoride content of
surrounding vegetation or ambient air concentrations. The most stringent
State regulation (as proposed in the State implementation plans), 0.15 pound
fluoride per ton of P205 input, would permit the typical 500-TPD P205 plant
to emit 75 pounds of fluoride per day.17 (This limitation, however, is based
on the analytical technique used by the State and cannot be directly compared
to the proposed standards of performance.)
RATIONALE FOR PROPOSED STANDARDS
Selection of Pollutants for Control
The major pollutants emitted from this process are fluorides and particulate
matter. Reasons for the decision to require control of only fluorides are
presented in the Introduction. Since control of fluoride Will inherently
provide some control of particulate, only an opacity standard is recommended
to assure particulate control.
Discussion
Preliminary investigations revealed the location of several reportedly
well-controlled plants. Six were visited, visible emissions were evaluated,
56
-------
and information was obtained on the process and control equipment. Four
were not further considered for testing because either fluoride fumes
were excessive in the processing area (perhaps the result of inadequate
maintenance) or the equipment (e.g., ductwork configuration) was not
suitable for accurate testing. Three tests were conducted at the remaining
two locations.
During the initial plant surveys, 6 plants with scrubbers exhibited no
visible stack emissions other than uncombined water vapor.
Two tests were conducted at Plant A. The results yielded average emissions
of 0.18 and 0.06 Ib F/ton P205, respectively. Source tests by the operator
on the same .day as the first EPA test indicated average emissions of 0.12 Ib F/ton
P2ฐ5'
The test at Plant B yielded average emissions of 0.21 Ib F/ton P00,-.
ฃ 5
Tests were conducted by EPA while the plant was operating at nor near its
design production rates. A complete summary of test data can be found in
Volume 2.
The proposed standard of 100 grams of fluoride per metric ton of P205 input,
(0.20 pound per ton) is supported by emissions measured during two tests of
Plants A and B as presented in Figure 16. This standard will require
installation and proper maintenance of equipment representative of the best
technology which has been demonstrated for the industry.
The Agency originally considered establishing a standard of 150 g F/metric
ton (0.30 Ib/ton) based on the measured emission data. However, upon
presentation of this standard at the NAPCTAC meeting on February 21, 1973,
the committee recommended the data be reviewed to see if a more stringent
57
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standard could be justified. Based on a revaluation, the following
conclusions were reached.
a. TSP plants are among the highest fluoride emitters in a phosphate
fertilizer complex. A reduction in fluoride emissions from 0.30 to
0.20 Wton P205 is equivalent to a reduction of about 30 pounds of
fluoride per day for a typical plant producing 300-350 tons of P?0j-
per day.
b. Tests by EPA showed that fluoride emissions of less than 0.2 Ib/ton
P205 can be achieved. EPA performed two tests [3 runs each) on a GTSP
plant. Fluoride emissions for all but one of the six runs were less than
0.2 Ib/ton P205.
c. Fluoride concentrations of three ppm, equivalent to Q.I Ib/ton of
P205 for GTSP plants can be achieved using packed scrubbers. CBased on
600,000 scf of exhaust gases per ton P^Og, typical of this process). ,
The proposed visible emission standard of 20 percent is based on data obtained
in February 1974. Visible emissions were read simultaneously by two qualified
observers during two 2-hour tests. Some data collected were not representative
of normal operation and were not considered in developing,the standard. At
*one GTSP plant visible emissions up to 25 percent opacity occurred while'
burning No. 5 fuel oil in the dryer. A check by plant personnel revealed an
abnormally large quantity of sediment in the fuel oil tank. Emissions from
identical dryers at other GTSP plants burning fuel oil have been observed at
less than 10 percent opacity.
On the basis of this information, in the Administrator's judgment, achievability
of the proposed standards has been adequately demonstrated.
59
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-------
GRANULAR TRIPLE SUPERPHOSPHATE STORAGE
SUMMARY OF PROPOSED STANDARDS
Standards of performance are being proposed for new granular triple
superphosphate (GTSP) storage facilities. The proposed standard would
limit emissions of fluorides from the storage building, which is the
affected facility. Major sources include but are not limited to the
product pile, transfer conveyors and elevators, screens, and mills.
The standards apply at the point(s) where emissions are discharged
from the air pollution control system or from the affected facility
if no air pollution control system is utilized.
The proposed standards would limit emissions to the atmosphere as
follows:
Total Fluorides
No more than 0.25 gram total fluoride, per hour per metric ton of
P205 in storage (5 x 10"4 pound per hour per ton).
Visible Emissions
Visible emissions shall be less than HO percent opacity.
DESCRIPTION OF PROCESS
After manufacture, GTSP is moved to a storage building where it remains
until the reaction is completed or the product is "cured." Figure 17
illustrates the activities in the storage building. The GTSP is distributed
61
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to a predetermined area in the building by conveyors. After 3 to 5 days,
during which fluorides evolve from the storage pile, the product is
considered cured and ready for shipping. Front-end loaders move the
GTSP to elevators or hoppers where it is conveyed to screens for size
separation. Oversize material is rejected, pulverized, and returned to
the screen.-Undersize material is returned to the GTSP production
plant. Material within specification is shipped as product.
EMISSIONS AND METHODS OF CONTROL
Emissions from GTSP storage are limited to fluorides and particulates.
The fluorides are emitted both in the gaseous form and as a constituent
of the particulate emissions. Emissions of gaseous and solid particulate
fluorides are greater during periods when the GTSP product is being
rearranged rather than when it is in piles where it has lain undisturbed.
Some poorly controlled GTSP storage facilities can release as much as
15 x 10" pound of fluoride per hour per ton of P00B in
storage. Such a storage facility with 1,500 tons of P20g could emit
-4
55 pounds of fluoride each day of storage. Well-controlled GTSP
storage facilities can restrict fluoride emissions to less than 5x10
pound fluoride per hour per ton of P205 stored (see Figure 18). A well-
controlled 1,500-ton PgOg storage facility achieving 5 x 10 pound of
fluoride per hour per ton of P205 stored would emit about 18 pounds of
fluoride each day of storage.
63
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The best-demonstrated control of fluoride consists of scrubbing emissions '
with water. No visible emissions -were observed from storage facilities
with this type of control. This-verifies. good control of fluoride and
also provides incidental control of particulate emissions.
Several State and local regulations limit fluoride emissions from
granular triple superphosphate storage facilities. Some restrict the
mass of emissions per unit of production. Others are based on the
fluoride content of surrounding vegetation or ambient air concentrations.1
The most stringent State regulation, 0.05 Ib F/ton P205 stored per day,
would permit a 1,500-ton P205 storage facility to emit 75 pounds of
fluoride per day.
RATIONALE FOR PROPOSED STANDARDS
Selection of Pollutants for Control
Only fluorides and particulates are potential pollutants from this
process. Reasons for the decision to require control of only fluorides
are presented in the Introduction. Since control of fluoride will
inherently provide some control of particulate, only an opacity standard
is recommended to assure particulate control
Selection of Units for the Standard
This is the only one of the affected facilities in the phosphate fertilizer
industry for which a standard of "pounds of fluoride per
ton of P205 input" was not considered to be applicable. The amount of
fluorides evolved from a storage pile is dependent on turnover, age, and
quantity of the GTSP in storage. The proposed units are based on the
quantity and age of the GTSP in the storage building. " 65
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Discussion
Preliminary investigations revealed the location of several reportedly well-
controlled facilities. Six were visited, visible emissions were evaluated,
arid information was obtained on the process and control equipment. Four
were not further considered for testing because the maintenance was
inadequate or the equipment (e.g., ductwork configuration) was not suitable
for testing. Three stack tests were conducted by EPA at the remaining
two locations. Both plants utilized packed scrubbers with gypsum pond
water as the scrubbing medium.
During the initial plant surveys, 6 plants with scrubbers exhibited no
visible emissions other than uncombined water vapor.
The tests conducted by EPA indicate average emissions from Plant A
are 4 x 10 pound fluoride per hour per ton of P^O,- stored (see Figure
18). The 6TSP storage building was about 21 percent full during.these
source tests.
-4
EPA's first test of Plant B indicated emissions averaged 1 x 10 pound
fluoride per hour per ton P^O,- stored. Concurrent testing by the operator
indicated 2xlO~ pound fluoride per hour per ton PoO,-- The 6TSP
storage building was approximately 30 percent full during this period.
66
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A second test of Plant B by EPA at a later date indicated 4 x 10 pound
fluoride per hour per ton of PoOc- During this .second test the storage
building was about 15 percent full.
Tests were conducted by EPA while 6TSP production was at or near design
production rates and more than 20 percent of the GTSP in the building was
manufactured within the 10 days prior to testing. .
Also, as noted above for each test, the storage buildings ranged from 15-30
percent full. A complete summary of test data can be found in Volume 2.
The proposed standard will require that a storage building be filled
to at least 10 percent capacity and that at least 20 percent of the GTSP
stored be fresh (produced no longer than 10 days prior to testing) during
a^compliance test. If the provision requiring'20 percent of the material
to be fresh exceeds production capabilities, the plant operator will be
required to have greater than five days maximum production in the building
during testing.
The minimum amount of product stored (10 percent of the building's capacity)
is required because the standard becomes unduly restrictive when very small
inventories are present in the building. The denominator in the units of the
proposed standard is the amount of material stored. If this quantity is
small the allowable pounds per hour of emissions is correspondingly small.
With low inlet concentrations to the scrubber (because of the small amount
of material stored), some fluorides may be stripped from the contaminated
scrubbing medium. Emissions in terms of "pounds per hour per ton P90,-
L- 0
stored" may then exceed the standard even though they are s.malj in terms of
pounds per hour.
67
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A minimum amount of fresh material is required to be stored during testing
since, as mentioned earlier, fresh GTSP evolves more fluoride than cured GTSP.
The proposed standard of 0.25 gram of fluoride per.hour per metric ton of
P205 in storage (5 x 10"4 pound per hour per ton) is supported by emissions
measured from the plants as presented in Figure 18. This standard will
require installation and proper maintenance of equipment representative of
the best technology which has been demonstrated for the industry.
The proposed visible emissions standard of 20 percent is based on data
obtained in'February 1974. Visible emissions were read simultaneously by
two qualified observers during two 2-hour tests.
In the Administrator's judgment, the achievability of the proposed standards
has been adequately demonstrated.
68
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REFERENCES
1. "Engineering and Cost Study of Emissions Control in The Phosphate
Industry," Chemical Construction Corporation under contract to the
Environmental Protection Agency (Contract CPA-70-156), unpublished
draft. August 1972.
2. "Fertilizer: The Figures are Looking Lots Better," Chemical
Marketing Reporter. April 17, 1972. p. 5.
3. "Clear Sailing Ahead for Fertilizer Phosphates," Chemical Week.
December 6, 1972. p. 31.
4. "Fertilizers: Global Accent," Chemical Week. September 27, 1972.
p. 11.
5. Oelschlager, vi., "Determination of Fluoride Standards for Vegetation
and Animals," Fluoride (Journal of the International Society for
Fluoride Research). Vol. 5, No. 3, July 1972. p. 111.
6. Leonard, C. D. and Graves, H. B., Jr., "Effect of Fluoride Air
Pollution on Florida Citrus," Fluoride (Journal of the International
Society for Fluoride Research). Vol. 5, No. 3, July 1972. p. 145.
7. Antonelli, Dr. Giuseppe, "Effects of Fluorine in the Regions Close
to the Industries that Produce it . . .," Rass. Trim., Odont. Vol. 35,
No. 2, April-June 1954. pp. 95-122. (Italian - English translation
obtained from EPA Air Pollution Technical Information Center.)
69
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8. Teller, A. J., "Control of Gaseous Fluoride Emissions," Chemical
Engineering Progress. Vol, 63, No. 3, March 1967. pp. 75-79.
9. Cross, F. L. and Ross, R. W., "New Developments in Fluoride Emissions
from Phosphate Processing Plants," JAPCA.. Vol. 19, No. 1, January 1969.
p. 15.
10. King, W. R., "Fluoride Emissions from Wet-Process Phosphoric Acid
Plant Gypsum and Cooling Ponds," presented at ACS National Meeting,
New York, N.Y. August 27, 1972.
11. Information obtained by EPA emission measurements or supplied by
phosphate industry producers in support of Industrial Studies Branch
program.
12. Reynolds, J. and Rom, J., "The Phosphate Industry Source Testing
Program," presented at TFI Conference on Environmental Control and
Fertilizer Production, Washington, D.C. May 4, 1972.
13. Slack, A. V., Phosphoric Acid. Vol. 1. Marcel Dekker, Inc.,
New York, N. Y. 1968.
14. "Wet-Process Phosphoric Acid." Chemical and Engineering News. Vol. 45,
March 20, 1967. pp. 54-58.
15. Illarionov, V. V. et al. Zh. Prikl. Khim. Vol. 36, 1963, pp. 237-241
(estimates of vapor pressure obtained by Russian investigators).
70
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16. Atmospheric Emissions from Wet-Process Phosphoric Acid Manufacturers,
U.S. Department of Health, Education and Welfare. NAPCA No. AP-57,
April 1970.
17. "Rules of the State of Florida Department of Pollution Control,"
Chapter 17-2, 1972.
18. "Control Techniques for Fluoride Emissions," U. S. Department of
Health, Education and Welfare, unpublished draft. May 13, 1970.
19. Sauchelli, Vincent, Chemistry and Technology of Fertilizer,
Reinhold Publishing Corp., New York, N. Y. 1960.
20. "Superphosphate: Its History, Chemistry, and Manufacture," U. S.
Department of Agriculture and Tennessee Valley Authority. December
1964.
21. Bixby, D. W. et al. "Phosphatic Fertilizers - Properties and
Processes," The Sulphur Institute, Washington, D. C., Tech. Bull.
No. 8. October 1966.
22. "1972 Directory of Chemical Producers," Stanford Research Institute,
Menlo Park, California. 1972.
23. "National Emission Standards Study," Senate Document No. 91-63,
U. S. Government Printing Office, Washington, D.C. 1970.
24. "Fluorides," National Academy of Sciences, Washington, D.C. 1971.
25. Tatera, Bernard S., Parameters Which Influence Fluoride Emissions from
Gypsum Ponds, Ph.D. Dissertation, University of Florida, 1970.
26. Personal communication with Dr. Aaron J. Teller, Ph.D., March 16, 1973
-------
-------
APPENDIX A
THE ECONOMIC IMPACT OF STANDARDS OF PERFORMANCE
ON THE PHOSPHATE FERTILIZER INDUSTRY
73
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I. Overvi ew
A. Scope
The purpose of this paper is to examine the background of the phosphate
industry and to analyze the economic impact of proposed standards of
performance upon the industry. The scope of this study is limited to
new sources only, that will fall under jurisdication of section lll(b).
After promulgation of standards of performance for a designated
pollutant, such as fluorides, existing manufacturing facilities become
subject to emission regulations under State implementation plans, similar
to those designed for achievement of national ambient air quality standards.
This requirement is under section lll(d) of the Clean Air Act. This
appendix does not discuss sources subject to section lll(d).
B. Summary
Costs for control of fluoride emissions under the standards of performance
for wet-process phosphoric acid (WPPA), superphosphoric acid (SPA), and
diammonium phosphate (DAP) manufacturing are minor, amounting to less than
1 percent in sales price at the wholesale level (phosphate producer). Costs
for emissions control for run-of-pile triple superphosphate is about 2
percent of wholesale price and for granular triple superphosphate, 4 percent.
The growth for new facilities in the phosphate industry will be fairly
substantial during the 1970's. A growth rate of an approximate 6 percent
is expected for new facilities in WPPA and DAP. Calculations yield 2 WPPA
units per year of the 900-TPD (P205 basis) size and approximately 3 DAP
plants (500-TPD PgOg) per year. No estimates have been made for replacement
of existing facilities; most facilities in the industry today are less than
ten years old. Some 3 SPA units of the 300-TPD (P205) size .will be built.
Little growth is expected for run-of-pile triple superphosphate produc-
tion; only slight growth is expected for granular triple superphosphate
because of increasing competition from diammonium phosphate and concentrated
liquids production (SPA), particularly in the area of manufacture of mixtures.
Projected granular triple superphosphate production is expected to be conducted
by complexes designed for multi-product operations. Therefore, facilities
equipped for DAP manufacture will also produce GTSP to satisfy demand for
direct application materials and overseas exports. Three new storage units
are expected to be built during the 1970's, each unit to accommodate 250-TPD
(P0OJ GTSP production.
-------
The impact of standards of performance upon the fertilizer industry
will be minimal, both for domestic consumers and the balance of trade.
While demand for phosphate products are relatively inelastic, cross
elasticities of demand do exist among competitive phosphate products (i.e.,
high analysis products vs. low analysis products, bulk goods vs. bagged
goods, solid fertilizers vs. liquid, for some samples of competition). The
standards of performance will not be a deterrent to those products that are
gaining acceptance with farmers. They will only accelerate this trend as con-
trol costs will further prohibit manufacture of run-of-pile triple superphosphate
and GTSP for the mixed fertilizers markets.
Lastly, a standard has been proposed for SPA to allow two competitive
manufacturing processes to remain as viable alternatives to producers;
namely, the submerged combustion and the vacuum evaporation processes.
A control cost of $0.28 per ton P205 for the submerged process has been cal-
culated for a system that represents a technology transfer from DAP manufacturing.
It is estimated that the vacuum evaporation process can attain 0.01 Ib F/ton
P205 without control. This would appear to be a cost disadvantage for the sub-
merged process; however, the impact of the standard upon the industry is
expected to be negligible. <
75
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II. Economic Profile
A. Industry Structure
The phosphate fertilizer industry is only a segment of the agricultural
chemical industry that is devoted to the production and marketing of com-
modities bearing the basic nutrientsnitrogen, phosphorous, and potash
for crop production. From the perspective of end-use products, the scope
of the agricultural chemical industry includes ammonia, ammonium nitrate,
urea, ammonium phosphates, nitrophosphates, mixed plant foods (in varying
N-P-K combinations), superphosphates, phosphoric acid, and potash. The
phosphate production sector of the" agricultural chemical industry begins
with the mining of phosphate rock, proceeds with the basic chemical produc-
tion of phosphoric acid and its subsequent processing to diammonium phosphate
(DAP), superphosphoric acid (SPA), and triple superphosphate (TSP), and
culminates at the retailer level where many thousands of-blends of fertilizers
are formulated to satisfy the diverse interests of consumers. There are three
basic types of retailersgranular NPK producers (manufacturers of chemical
formulations), liquid fertilizer manufacturers, and mechanical (dry bulk)
blenders. These three groups of retailers compete with each other in some
markets (mixed fertilizers).
The basic chemical producers in the industry will sell merchant phosphoric
acid and products derived from phosphorie acid, such as DAP or SPA. NPK pro-
ducers can buy from a choice of raw materials then to produce a specific product.
For example, the typical NPK plant operator can buy DAP or produce his own from
wet-process phosphoric acid to satisfy a product demand. Therefore, some com-
petition can be expected among the various phosohate concentrates.
The basic chemical producers, which are the focus of this analysis, are
generally not identifiable as single product firms. Very few firms are
totally dependent on fertilizer production for their business. Most fertilizer
production is conducted as a subsidiary activity in well diversified, often-
times large, corporations. These firms are chemical manufacturers or
petrochemical companies. Some companies are farm cooperatives, vertically
integrated from production to the marketing in geographic areas in which they
are economically based. These latter firms are primarily engaged in serving
farm customers in ways such as retailing fertilizers, purchasing and shipping
grains and other agricultural products to regional centers, and providing necessary
supplies and services for conduct of an agricultural economy. Thirdly, there
76
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are firms engaged in fertilizer production that derive the main portion
of their revenues from totally unrelated activities, such as steel manu-
facture, pipeline construction, etc.
Generally, the basic chemical producers will own the sources of their
raw materials (e.g., phosphate rock mines). According to 1970 production
statistics^ , the ten largest firms in rock mining are ranked as follows:
TEN LARGEST PHOSPHATE ROCK'PRODUCERS
Firm
International Minerals & Chemicals
Continental Oil Company (now Williams Co.)
Mobile Chemical
Occidental Chemical Company
American Cyanamid
U.S.S. Agrichemicals
Swift & Company
Texas Gulf, Inc.
Stauffer Chemical Company
Cities Service, U.S. Phosphoric
Total U.S. Production
Percent of total production of ten largest firms
Based on the production of wet process phosphoric acid, which is the cornerstone
of the basic chemical production in this industry, the ten largest firms in terms
of 1972 production are as follows:
TEN LARGEST PHOSPHORIC ACID PRODUCERS
Production
(1000 Short Tons)
8,000
6,500
5,900
3,750
3,650
3,640
3,000
3,000
2,500
2,000
50,640
83%
Firm
Production
(1000 Short Tons,
CF Industries 838
Freeport Minerals 600
Cities Service, U.S. Phosphoric 544
Farmland Industries 455
Beker Agricultural Products 411
Texas Gulf, Inc. 346
01 in Corporation 337
W. R. Grace 300
U.S.S. Agri-Chemicals 266
J.R. Simplot 265
Total U.S. Production 6,114
Percent of total production of ten largest firms 71%
A review of the two above tabulations finds some vertical integration from
the mine through the chemical production. Each of the phosphate rock producers
named above owns basic chemical production facilities directly or through equity
interest in chemical producing companies. CF Industries and Farmland Industries
are integrated from the chemical production stage forward to the ultimate retailing
77
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of fertilizers. Freeport Minerals is strong in ownership of sulfur reserves, an
important raw material for production of phosphoric acid. Beker Industries
is a newcomer into the fertilizer industry as they purchased the fertilizer
assets of Hooker Chemical (Occidental Petroleum) and El Paso Products Company.
B. Production
The scope of this study limits discussion to four basic commodities that
are produced and traded. These are wet-process phosphoric acid, superphosphoric
acid, triple superphosphate, and ammonium phosphates. Production data for 1960
through 1971 are presented in Table 1 for these commodities. A discussion of
the features of these commodities follows.
1. Wet-Process Phosphoric Acid
The production of this chemical intermediate, which is the cornerstone
of the industry, has grown at a phenomenal rate of 14 percent compounded
annually for the period shown in Table 1. The growth has been due to the
increased demand for phosphate nutrients over the years and due to the sub-
stitution from low analysis to high analysis products (triple superphosphate
and diammonium phosphate) that require phosphoric acid for their production.
High analysis products contain some 45 to 50 percent P20g as opposed to 18
to 24 percent P205 in low analysis products, such as normal superphosphate.
Wet-process phosphoric acid is used to produce triple superphosphate, .
diammonium (or monoammonium) phosphate, superphosphoric acid and complete NPK
foods (those containing some formula of nitrogen, potash, and P205)- Normally
phosphoric acid is produced very near the rock mines to minimize the shipping
charges as phosphoric acid is a more concentrated product than phosphate rock.
2. Triple Superphosphate
The production of triple superphosphate has been in a downtrend since 1966,
which may indicate a likely course for future trends in production of run-of-pile
triple superphosphate and a close substitute, monoammonium phosphate. Since
1900, triple superphosphate has grown at a compounded rate of 4 percent.
Triple superphosphate is produced by two methods; the den method and
the granulator method. The den method produces a material (run-of-pile)
that is non-uniform in particle size. This material is stored, pulverized,
and shipped to NPK plants for ammoniation. The granulator method produces
a granular product that is sold to bulk blender retailers for mixing or
for direct application (as a 0-46^0 fertilizer) to the soil.
No statistics are available as to the breakdown of run-of-pile versus
direct granulator production. In the industry, run-of-pile production by
the primary producer may be granulated and sold as GTSP to bulk blender
78
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TABLE 1. U.S. PRODUCTION OF THREE COMMODITIES IN THE PHOSPHATE INDUSTRY. 1960-1971
Year
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
Wet> Process
Phosphoric Acid
1325
1409
1577
1957
2275
2897
3566
3752
3861
3867
4642
5286
(1000 Tons of
Triple Super-
phosphate
986
1024
960
1113
1225
1466
1696
1481
1389
1354
1395
1381
W
Ammonium
Phosphates
269
370
536
786
1016
1081
1376
1747
1633
1844
2070
2359
Superphosphoricc
Acid
35
55
55
75
120
188
260
418
NA
NA
NA
NA
All grades containing 40 percent or more available P^O,- which have been made by
acidulating rock with phosphoric acid.
Mono- and diammonium phosphates and their processed combinations with ammonium
sulfates. Excludes ammonium phosphates produced in combination with potash salts.
Production derived from thermal acid and wet-process phosphoric acid, based on a
marketing study of the industry conducted by Chemical Construction Company.
NA - Not available.
SOURCE: U.S. Department of Commerce, Current Industrial Reports.
79
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retailers as a direct application fertilizer. Ultimately, essentially all run-
of-pile production becomes granulated, either by the primary producer or by the
NPK plant.
Triple superphosphate affords a way of shipping P^ values in a
concentrated form, whether for distribution into domestic markets or for
exports. Some 80 percent of triple superphosphate plant capacity is
located in Florida near the rock mines.
3. Ammonium Phosphate
By definition, these are products manufactured directly from arnnoma,
phosphoric acid, and optionally other acids in contrast with those ammoniated
phosphates produced in NPK granulation plants from ammonia and run-of-pile
triple superphosphate. "Diammonium" phosphates include 16-48-0 and 18-46-0
grades. Monoammonium phosphates are 11-48-0. These two generic products
are produced strictly from ammonia and phosphoric acid; other ammonium phosphates
are produced from a mixture of ammonia, phosphoric acid, nitric acid, and
possibly sulfuric acid.
Production of arrcnonium phosphate has grown at a rate of 20 percent com-
pounded annually since 1960. The rapid growth has been at the expense of
other competitive phosphate fertilizers. The following statistics will
support this. In 1960, ammonium phosphates absorbed 20 percent of wet-
process phosphoric acid production; in 1971, 45 percent. In contrast,
triple superphosphate absorbed 52 percent of wet-process phosphoric acid
production in 1960 and only 18 percent in 1971. (One ton of P205 in triple
superphosphate requires 0.7 ton of P205 from phosphoric acid.)
NPK and superphosphoric acid production consume the remainder of wet -
process phosphoric acid that is not used in ammonium phosphate and triple
superphosphate processing.
4. Superphosphoric Acid
Superphosphoric acid is a concentrated form (70-75 percent P205) of
thermal or wet-process phosphoric acid. Phosphoric acid is concentrated ^
by two methods-(a) vacuum evaporation technique, and (b) submerged combustion
process.
Documentation of superphosphoric acid production is very limited.
The usual reporting groups, such as Department of Commerce and TVA, do not
report production figures. The Fertilizer Institute reports production
80
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in its Fertilizer Index but privately concedes that its published figures
for the years of 1969-1971 are far below estimates of actual production.
Dr. William White^ of the Fertilizer Institute estimates that 1972
production approaches 600,000 tons (P205 basis). This is signi-
ficantly different than the 258,000 ton figure published in the Fertilizer
Index for the 12-month period ending in June 1972.
Superimposing the 600,000 estimate on an imaginary trend line with data
developed by Chemical Construction Company^ ' would reinforce the. Tatter's
data trend. Linear regression analysis of the Chemical Construction Company
data yields an historic growth rate of 35 percent from 1960 through 1968.
C. Capacity
The phosphate fertilizer industry has followed a cyclical pattern of capital
investment in new plants. This pattern is demonstrated by the two graphs for
phosphoric acid and ammonium phosphate (mostly diammonium phosphate; this term
will be applied to ammonium phosphates produced directly from wet-process
phosphoric acid) production, shown in Figures 1 and 2. As shown in the graphs
by the duration between peak utilization (operating near 100 percent), the cycle
length is about 6 to 7 years. During the 1965 to 1972 cycle, expansion peaked
in 1969. Slackened demands prompted price cutting and eventual temporary shut-
down of some facilities. At the end of the cycle, supply of plant capacity
becomes in balance with production.
For an insight into the cyclical trend of capacity utilization, the
following operating ratios are presented for phosphoric acid and diammonium
(4)
phosphate production.
Year
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
Production, as Percent of Capacity
WPPA
100
92
80
77
69
84
96
96
89
89
83
82
DAP
72
63
66
56
54
78
96
96
81
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FIGURE 1. CAPACITY UTILIZATION QF WET-PROCESS PHOSPHORIC ACID
jfc-|Miii|^
2750
[ 65 66 67 68 69 70 71 72 73 74 75 76 77
|L-;Ld^L;-i-il-ii^-:-^ :.l:-.u._--_i::_.;-. _i~-
,SOURCES: Development Planning & Research Associates, TVA
82
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During mid-1973, the industry was operating near capacity. Idle plants that
had been shut-down during the 1968-1970 recession were being refurbished for
production. Beker Industries is one example of a firm that purchased idle
phosphate facilities from petroleum companies for acid and ammonium production.
New plant construction as announced by Agrico Chemical and IMC will not pro-
vide significant additions to supply of phosphates until 1975 to 1976. By
inspection of the profiles in Figures 2 and 3 and the operating ratios pre-
sented above, planned plant capacity for phosphoric acid seems sufficient
through 1976; and ammonium phosphate capacity, on the other hand, will have
.to be increased to cope with the projected demand.
D. Consumption
For an understanding of the historical consumption patterns of the four
commodities named above, an overview of consumption of all phosphate fertilizers
is presented. Although some superphosphoric acid is consumed ultimately in
the form of animal feed supplements, almost all phosphate production
from wet-orocess phosphoric acid ends up UL.fejr.tilizers..
Historical data are presented tor U.S. consumption (total consumption,
mixtures, and direct application materials) in Table 2, Liquids and solids (bulk
and bagged) are all included in these data. Total consumption includes phosphate
values derived from wet-process phosphoric acid to produce triple superphosphate,
and phosphate rock reacted with sulfuric acid to produce normal superphosphate.
Overall, the growth trend in total consumption has been at a rate of 6.5
percent compounded annually from the base year 1960. However, normal superphosphate
production has declined steadily from 1,270,000 tons (P205) "in I960 to 670,000
tons (P90c) in 1970. The gap in phosphate values generated by the decline in NSP
ฃ, O
has been mostly taken up by diammonium phosphate production, as well as wet-process
phosphoric acid, the intermediate product. Hence, consumption of wet-process
phosphoric acid and diammonium phosphate production have grown at a more rapid
rate than total, consumption of phosphates.
The two other major categories presented in Table 2 separates the basic
chemicals that are applied directly to the soil from those that receive further
processing into mixtures.; foods containing at least two of the nutrients'basic to
plant growth. Some duplication of reporting is evident in the TVA statistics as
some undetermined amount appears twice, in "mixtures" and "direct applications"
85
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Review of the data in Table 2 shows that demand for materials with only one
or two basic nutrients, the ammonium phosphates, has been very important in recent
years. Ammonium phosphates, other than DAP, and normal superphosphate have
declined in importance as "direct application materials". Almost all direct
application materials are now DAP or GTSP. Demand for these materials appears
to have grown more rapidly than total consumption., Two explanations for this
trend are the rise of bulk blending operations and intensive cultivation (emphasis
on increased yield per acre).
Delivery of low cost fertilizer materials to the farm has been the factor
responsible for this trend. Farmers have lately realized that mechanical blends
of granulated concentrates do just as well as a granulated, chemically produced
NPK food and at lower costs. A shift from normal superphosphate and run-of-pile
triple superphosphate production to the granulated concentrates, DAP and GTSP is seen.
The shift in product usage has also been accompanied by a shift in raw materials
for NPK plants. Run-of-pile triple superphosphate has been replaced by wet-
process phosphoric acid as a raw material. Improvement in phosphoric acid
technology has made it possible to ship a stable product, as most NPK plants
are far removed from the areas of acid production (Florida^ for example).
Consumption of superphosphoric acid is only recently beginning to enter an
important expansion phase. Data for consumption is limited. To this point in
time, the acid has been used for producing some animal feed supplements and mostly
liquid fertilizers. Superphosphoric acid consumption is estimated at only 15
percent of overall phosphate consumption.
Several reasons are presented to explain the expected expansion of super-
phosphoric acid consumption. Technology has made it possible to produce a
product without the problems of sludge formation due to presence of micronutrients.
Increased crop yield per unit PgOg applied from liquids fertilizers has
been claimed. Transportation and distribution costs of liquids are less
than for solid fertilizers. The need for foreign exchange spurs superphosphoric
acid production, particularly in light of the recent Occidental Petroleum
announcement of a 20 year trade deal with Russia..
The implications of all the shifting patterns in the industry in response
to shift in demands for cheaper, better quality products are as follows:
86
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1. Granular concentrates will continue to expand in production; these in-
clude DAP and GTSP.
2. Run-of-pile production will decline and be replaced by GTSP (bulk
blender) and diammonium phosphate.
3. Superphosphoric acid will have the largest growth rate of the four commodities
These will be important factors in determining growth rates for each
process segment and the number of new units.
E. New Units
Future growth for consumption of fertilizers has been estimated at 5.4 per-
cent annually from the base year of 1971^ ' by the Department of Commerce. TVA
estimates overall consumption of P205 to be 4 percent from 1970 to 1980.^7'
Projection of new units will be determined from use of projected growth rates,
capacity utilization, and estimated shifts in demand. Due to the present
situation in this industry, attrition through 1980 is expected to be minimum
(with the exception of normal superphosphate processing).
1. Het-Process Phosphoric Acid
For purposes of discussion, the announced construction of wet-process
phosphoric acid plants is assumed to satisfy demand through 1976 and will
be unaffected by the recommended standards of performance. This includes
the Agrico and the IMC facilities, which recently have commenced construction.
A growth rate of 5 to 8 percent in wet-process phosphoric acid production can
be expected to accommodate overall phosphate demand for domestic consumption and
exports growth and to -replenish gaps left by normal superphosphate production.
Calculations of added capacity needed to supply this demand will yield
annual expansion of approximately 600,000 tons (Pp^r basis) for a 6-per-
cent growth rate. For the 1976 through 1980 time frame, this will amount
to 10 units of the 900-TPD size or 18 units of the 500-TPD size. .
2. Piammonium Phosphate
From interpretation of available statistics, there is apparently a
catch-up phase expected for this category in terms of present capacity
utilization and expected demand growth.
.Overall, the growth rate of ammonium phosphates is projected at 6
percent to correspond with the similar increase in wet-process phosphoric .
acid. It is difficult to predict number of new units to be affected by
87
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the standards of performance because they apply only to units that
produce diammonium phosphate only in a single process. Much of the pro-
jected growth in ammonium phosphates -v/i 11 be supported by NPK production.
A conservative assumption for determining number of new diammonium
phosphate plants would be to assume that three-fourths of production for
each new wet acid plant will be devoted to solids manufacture, either DAP
or 6TSP. This would allow the remainder to be sold as merchant wet-process
phosphoric acid or superphosphoric acid. This is based on past performance of the
concentrates producers, such as those in Florida. In actual estimates then, there
will be approximately 20 DAP units of the 500-TPD size through 1980.
3. Triple Superphosphate (Granular Only)
Based on earlier discussion, only granulated concentrates are expected
to be of importance in the future for the triple superphosphate. Further-
more, only those producers of wet-process phosphoric acid will manufacture tripTe
superphosphate as has happened mostly in the past.
According to information sources in the industry, the trend in qranular
production is to conduct triple superphosphate processing in the same facility
producing diammonium phosphate. The only additional requirement for GTSP
production in a DAP plant would be the storage facility.
For purposes of determining new storage units, an assumed growth rate
of 4 percent in current granular production (approximately 700,000 tons
per year PgOg) will yield 2-3 units (250-TPD P205) through 1980. This
growth rate would be consistent with past performance for all triple super-
phosphate production.
4. Superphosphoric Acid
From all indications, this portion of the industry is expected to
expand rapidly. Whether this expectation is realistic or a reflection of
bold optimism is unknown. Ultimately, the availability of merchant wet-
process phosphoric acid will be the factor that determines the constraints
on SPA expansion.
88
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F.
For the industry as a whole, only enough expansion will occur to
convert available acid that is not used to produce concentrates. This
is axiomatic if the industry is to operate profitably. Approximately
twent-five percent of all future WPPA expansion can be projected to accomo-
date SPA plants. Taking into account the Agrico and IMC combined new
facilities (1,000,000 tons P205 per year total) and the projected expans-
ion from 1976 through 1980, some 10 SPA plants will be built (300-TPD Pp05).
Prices
Price competition in the fertilizer industry has been very intense historically
because of the large numbers of participants in all facets of manufacturing--
basic chemicals production, down-the-line manufacturers of mixed goods, blenders,
and retailers. No one chemical producer can be said to.be a price leader. The
participation of farm cooperatives in the manufacturing segment of fertilizers,
including the basic chemicals, undoubtedly has been a steadying factor on
prices, minimizing cyclic fluctuations in prices.
List prices are available for (agricultural grade) wet-process phosphoric
acid, triple superphosphate (run-of-pile and granular), diammonium phosphate,
and superphosphoric acid grade (72 percent available phosphoric acid basis) in
the Chemical Marketing Reporter published by Snell Publishing Company of New
York. These prices, however, are not meaningful as discounts, variability in
credit terms to buyers, and service fees combine to determine the realized
price available to the producer.
The long term profile of wholesale prices for triple superphosphate
(granular) and diammonium phosphate is presented in Figure 3. The
estimates of prices realized by manufacturers are plotted against the ranges
of listed quotations of the same products for 1971 and 1972. The spreads in
prices shown reflect the difference in quotations by various manufacturers at
any given time rather than variability in time. No long term profile of prices is avail
able for wet-process phosphoric acid, superphosphoric acid, and triple superphosphate.
These prices will be used as parameters for measuring the impact of
pollution control. Total annualized control cost and the difference in
control costs between existing, comparably stringent state standards and pro-
posed Federal standards of performance for triple superphosphate and diammonium
phosphate will be measured against prices (1972) for the respective products.
89
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-------
A summary of list prices (December 25, 1972) is presented in Table 3 for
all commodities concerned. Point of origin for all quotations is Florida.
Prices are based on largest volume available, railroad cars or tanks.
On October 25, 1973, prices on wholesale phosphate commodities
were decontrolled. Prices had been frozen at levels established near
year-end 1972 prices by President Nixon's Economic Stabilization Program.
According to the Cost of Living Council, prices have advanced 60 per-
cent from the October 25 frozen level to January 8, 1974.
G. Foreign Trade
Trade statistics for triple superphosphate and ammonium phosphates (mostly
DAP) are presented in Table 4. No data are available for phosphoric acid
(wet-process or SPA), probably for the reason that trade has been non-existent
because of transportation properties associated with movements of acids.
As the data show, the U.S. has been an exporter of phosphates, on balance.
The reasons for this include technological competition, favorable location of
rock, and the Agency for International Development (AID). Under AID, export
purchases of products have been possible by underveloped nations through U.S.
foreign aid. AID providestechnical assistance, as well as financing of
fertilizers, to these nations in fertilizer applications.
The recent unilateral devaluation of the dollar has placed the domestic
industry in a favorable position by pricing American products at discounts
relative to the foreign currencies of competive producing nations. This
should be beneficial to the domestic producers at least for the short to
intermediate term.
91
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II. Control Costs for Affected Facilities
A. Introduction
The purpose of this section is to report the expected capital and
annual costs to control emissions from wet-process phosphoric acid, super-
phosphoric acid, diammonium phosphate, and triple superphosphate (run-of-
pile and granular) processes. Estimates of control costs will be
presented for two model plants for each process. These estimates will be
based on information developed from a study under contract with the
Industrial Gas Cleaning Institute/8' Comparisons of these data with industry
data submitted to the Environmental Protection Agency will be presented and
discussed. Cost-effectiveness considerations for fluoride control will be
discussed.
B. General Digcussion of Control Alternatives
Basically, venturi, cyclonic, and packed scrubbers are applied to
moisture laden streams carrying fluorides from process plants.
Each process stream has certain characteristics that require
various service functions--(l) recovery of ammonia or phosphoric acid which
are valuable materials, (2) gaseous fluoride control, and (3) dust recovery
from granulation. These functions will come into focus as model plants for
the various processes are discussed.
These scrubbers will be referred to as primary and secondary collectors.
Primary scrubbers serve to remove particulates, phosphoric acid mists, and
ammonia. Secondary collectors perform gaseous absorption. Pond water
is the general scrubbing medium, except for weak phosphoric acid used to
recover ammonia (DAP plants).
C. Control CostsAcid Manufacture
1. Wet-Process Phosphoric Acid
Model plants producing 500 and 900 ton per day (P205) are presented
in Table 5 for WPPA plants. Capital and annual costs are presented
for packed scrubbers with the scrubbing liquid sprayed on the packing
perpendicular to the direction gas flow designed to remove fluorides.
Capital costs include a scrubber, fan, water circulating pumps, 120
feet of ductwork, and a 100 foot stack. All surfaces exposed to
scrubbing (pond) water are coated with polyvinyl chloride (PVC) or
similar corrosion resistant material.
94
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TABLE 5
CAPITAL AND ANNUAL COST FOR; PACKED SCRUBBER ON WPPA PLANTS
Plant Size, TPD P205
Gas Flow.SCFM
Capital Cost ($)
Scrubber
Auxiliary equipment
(fan, pumps, etc.)
Installation Cost
Total Capital Cost
Annual Cost ($/yr)
Operating labor
Maintenance (5%)
Utilities
Depreciation (10 yr)
Interest (8%)
Property Tax, Ins. (2%)
Administrative (5%)
Total Annual Cost
500
25,000
17,700
8,500
36,300
62,500
2,000
3,100
2,800
6,250
5,000
1,250
3,100
23,500
900
36,000
21 ,600
9,400
40,900
71 ,900
2,000
3,600
! 4,400
7,200
5,750
1 1 ,450
1 3,600
28,000
95
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For the models, the packed scrubber is designed to meet the
standard under most operating conditions, using pond water as the
scrubbing medium. The scrubbers are assumed to be designed for
approximately 4.5 transfer units, with a corresponding pressure drop
of approximately 4 inches, water gauge.
The annual control cost per ton P20g ranges from $0.135 to $0.221
for the 500-TPD plant and $0.08 to $0.152 for the 900-TPD plant.
These ranges are a reflection of the variability in gas flows pre-
viously discussed.
2. Superphosphoric Acid
Costs for the vacuum evaporation process are not considered
since, as mentioned earlier, the process can probably achieve the
level,of the standard without air pollution control. Model plants
are presented for the submerged combustion process.
For the submerged combustion process for producing superphos-
phoric acid, control technology to meet the standard of performance
has not been tested to determine compliance. Experts in EPA feel
that technology transfer of a venturi cyclonic-packed scrubber from
applications on other phosphate processes is possible to achieve the
standard.
For a 300-TPD P2Gg model plant, capital and annual control costs
estimates are presented in Table 6 for a combination system that would
be found on a diammonium phosphate drier or reactor. The basis for
developing these estimates is the background data presented in Table 7.
The cost for the packed scrubber was slightly adjusted to correct for
increased packing depth (to 8.9 NTU). A gas flow rate of 8,000 scfm
was assumed for determination of the costs. The cost of control on a
unit basis is $0.28 per ton P0.
96
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TABLE 6
CAPITAL AND ANNUAL CONTROL COSTS FOR SPA PLANTS
(SUBMERGED COMBUSTION PROCESS)~
Control Equipment
Venturi scrubber with cyclonic separator
followed by a paeked scrubber
Gas Flow Rate ACFM
8,000
Capital Costs ($)
Collector
Auxiliary Equipment (fans, pumps,
ductwork, instrumentation)
Installation Cost
Total Capital Cost
18,400
9,500
41,000
68,900
Annual Cost ($/yr)
Operating Labor
Maintenance (5%)
Utilities
Depreciation (10 yr)
Interest (8%)
Property Tax and Insurnace (2%)
Administration (5%)
Total Annual Cost
2,000
4,000
5,010
6,920
5,540
1,380
3,460
27,800
97
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The system outlined above to meet the standard does not remove
any sulfur oxides emissions to any known extent. -The system is
designed to remove only particulate and fluoride emissions.
D. Control Costs - Phosphate Fertilizer Manufacturing
Capital and annualized cost estimates for emissions control are pre-
sented in Table 7 for five generic types of devices used in phosphate
fertilizer manufacturing. These estimates are presented on an uniform
dry gas flow basis. Moisture and temperature considerations will dictate
the final size selection as capital estimates for the model plants will be
based on the actual gas flow input. Utilities requirements will be direct-
ly proportional to actual gas flow input.
Capital costs include the basic scrubber, the fan, interconnecting
ductwork from the scrubber to the 50-foot stack (assumed height), which
is included, and a return pump. Materials of construction include
rubber-lined mild steel or Dyne! lined fiberglass reinforced plastic (FR.P).
Costs for a pumping system to recycle gypsum pond water and the con-
struction and maintenance of the gypsum pond itself are not included.
These costs are assumed to have been assimilated into the cost structure
of the fertilizer industry.
1. Diammonium Phosphate (DAP)
Model plants producing 500 and 800 tons of P20r with engineering
specifications for estimating costs are presented in Table 8. There
are three distinct gas streams that must be vented to a scrubber
system(a) reactor-granulator, (b) the drier, and (c) the cooler
and combined exhausts from elevators, screens, and transfer points.
Those streams in the solids processing area pass through dry cyclones
for product recovery before passing through the scrubbers. Each
scrubber system includes a venturi with a cyclonic section (a two
stage cyclonic scrubber may be a substitute device) as the primary
collector for particulate removal and a packed scrubber for the
gaseous fluoride removal.
Weak (30%) phosphoric acid is the scrubbing medium for the primary
collectors for purposes of ammonia recovery. The cyclonic section is
an entrainment separator for phosphoric acid mists. Pond water serves
as 'the scrubbing medium for the packed scrubbers.
98
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A summary of control costs for the model plants is presented In
Table 9. A two-stage cyclonic scrubber is assumed for the reactor-
granulator stream, and venturi cyclones for the drier and cooler-
transfer points streams. The venturi should remove particulates from
the latter streams more effectively than a two stage cyclone although
both types are interchangeable. Total control costs with MM-
credits are $0.88 per ton P205 for the 500-TPD plant and $0.70
for the 800-TPD plant. Gaseous fluoride control costs alone are
$0.46 per ton P205 for the 500-TPD plant and $0.40 for the 800 TPD
plant.
2. Triple Superphosphate (GTSP and ROP)
In reference to earlier discussions, granular triple super-
phosphate will be produced in the same facilities as diammonium
phosphate. The same basic control equipment could be used,-.in the
manufacture, of both Products, although triple superphosphate production
requires approximately twice as much recirculation of solids during
granulation as does DAP per unit output. Hence, gas volumes generated
for equivalent P20g production will be significantly larger for triple
superphosphate. In addition, storage ventilation will require
scrubbing.
Engineering specifications for estimating control costs are pre-
sented in Table 10 for two models to produce 250-TPD and 400-TPD
P205. Venturi-packed systems are assumed installations for models
in lieu of venturi-cyclonic and packed combinations. This
would be the situation for the facilities where ammonia recovery is
practiced only at the reactor-granulator during DAP processing.
A summary of control costs for granular triple superphosphate
production is presented in Table ,11. Unit costs for all control
systems are $3.-96- per ton P20g for the 250-TFD model and $3.56 per
ton P20g for the 400*TPD plant. Storage control costs alone are $0.57
per ton P20g for the smaller plant and $0.50 per ton P20g for the
larger plant.
Run-of-pile triple superphosphate production requirements
for emissions control to meet the standards of performance
ar2 presented in Table 12. Gas streams from the den, cutter, and
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TABLE 12.
CAPITAL AND ANNUAL CONTROL COSTS FOR RUN-OF-PILE TRIPLE SUPERPHOSPHATE PRODUCTION
Model Plant Size ^205)
A. Engineering Specifications:
Gas to Scrubber, ACFM
Collector
Scrubbing Medium
B. Cost Summary
1. Capital Requirements ($)
2. Total Annual Cost ($)
250-TPD
400-TPD
I
60,000
Venturi Cyclone
100,000
Venturi Cyclone
Pond Water { Pond Water
315,000^
135,000
3. Unit Control Costs ($ per |
ton P205) 1-64
1
450,000^
200,000
1.52
* 'Scrubber portion of costs is $60,000; auxiliary and installation costs are
$255,000.
^ ^Scrubber portion of costs is $90,000; auxiliary and installation costs are
$360,000.
105
-------
storage are assumed to be combined and treated in a central collec-
tion system. This is generally the practice in industry today.
Control technology consists of a venturi cyclone followed by a
packed scrubber, all with pond water as the scrubbing medium.
For the selected model plants, unit control costs are $1.64 per
ton P205 for the 250-TPD plant and $1.52 per ton P205 for the 400-
TPD plant. The basis for the capital estimates are the purchase
costs of the venturi cyclone (A) in Table 7 and for the packed
scrubber in (E); with auxiliary and installation costs for a storage
facility (D).
E. Documentation of Reported Industry Data
All data reported to EPA by industry for emissions control systems
which are considered best demonstrated technology for their respective
process plants have been compiled and analyzed. A tabulation of these
data and EPA estimates derived for comparable bases are presented in Table
13> The industry reporting has been sparse, and only qualitative infer-
ences can be drawn from their analysis.
Statistics are presented in Table 13 for process capacity, plant
(battery limits) capital, control systems, capital, and year of installa-
tion. The capital estimates reported by industry are in actual dollars
and have not been corrected for inflation. EPA estimates are in 1973
dollars and have been developed from plant models presented earlier.
Operating costs have not been analyzed due to insufficient, inconsistent
reporting.
In general, capital estimates of fluoride emissions control systems
are in agreement with EPA estimates for wet-process phosphoric acid,
superphosphoric acid, and granular triple superphosphate processing.
EPA estimates for run-of-pile production appear low probably because the
costs for piping and ductwork associated with ventilating the storage area
have been omitted.
106
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In terms of percents of battery limits plant capital, emissions
controls for solids processing as shown by the data for ROP and GTSP,
are the highest for any process. Emissions control capital ranges
from 15 to 25 percent of battery limits plant capital for these process-
es. Control systems for wet-process phosphoric acid production are
5 to 10 percent. Controls for superphosphoric acid production are
about 6 percent for the submerged combustion process.
No conclusions can be drawn from the reported industry data concern-
ing the impact of the recommended standards of performance
F. Cost-Effectiveness
All processes considered for standards of performance have been
assumed to require packed scrubbers as the best available demonstrated
control technology. The effectiveness of these scrubbers is based on
the principle of a concentration gradient between gaseous fluorides in
the effluent stream and the vapor phase in equilibrium with the scrubbing
medium. The outlet concentration of the clean gas is limited by the
concentration of the fluorine in the pond water (which is somewhat a
function of the pH) and the water temperature, both factors determining
the vapor pressure of fluoride in equilibrium with the liquid phase of the
scrubbing pond water. Removal efficiency, or adsorption efficiency
(measured in transfer units) requirements depend on the concentration
of fluoride in the process streams. Key design factors governing the
number of transfer units are packing depth and packing materials.
The relationship of cost vs. adsorption efficiency for packed
scrubbers common to the industry is presented in Figure 4 for a range
of 3 to 7 transfer units. The annualized cost of the scrubber for a
500-TPD P205 wet-process phosphoric acid plant is selected as the para-
meter in Figure 4. The choice of the effluent gas stream of a wet-
process phosphoric acid plant is appropriate in discussion of cost-
effectiveness because this emission source is probably the most signi-
ficant of all sources under consideration and offers a wide range
108
-------
1_ PROPOSED STANDARDS OF PERFORMANCE FOR PHOSPHORIC ACID PLANTS.
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109
-------
of absorption efficiency possibilities, depending on choice of packing
depth. An underlying assumption for these costs are the design condi-
tions of pond water temperature, selected as 80ฐF, and acid concentration
(hydrofluoric), measured as pH 2.0. In the day-to-day applications,
absorption efficiency will vary as these characteristics of the pond
water change.
For the-purpose of illustrating cost-effectiveness, four levels of
control with the appropriate costs are presented below.
Incremental Incremental
Total Fluorides Cost per
Captured..
Level Efficiency, %
A 95.00
B 98.90
C 99.40
D 99.91
Based on 500-TPD model plant (see Table 5)
Based on emission rate of 1.8 F per ton P205<
Annual
Cost, $(')
23,380
23,500
23,900
24,450
Incremental
Cost, $
23,380
120
400
550
Tons/Year^2)
141
5.8
0.74
0.6
Incremental
Ton, $
166
20.7 (B over A)
540 (C over B)
724 (D over C)
As the results show, cost per unit of fluoride captured decreases
somewhat above the base level efficiency of 95 percent. The reason for
this is that much of the capital, which is spent for installation and
erection of the control device, and operating costs for labor and utilities
would be unchanged for the fpur control levels. As absorption efficiency,
approaches level D, cost per unit rises rapidly and will rise exponentially
beyond D as pond water equilibrium conditions are approached by the
fluoride content of the effluent gas stream.
The following tabulation shows the required transfer units to comply
with proposed limits the phosphate manufacturing processes subject to
standards of performance,
Source Standards of Performance MTU
0.02 Ib F/ton P20g 4.5
0.06 Ib F/ton P205 2.0
0.20 Ib F/ton P205 3.0
0.20 Ib F/ton P205 4.5
0.0005 Ib per hr F/ton P^ 1.0
0.01 Ib F/ton P205 8.9
WPPA
DAP
GTSP
ROP-TSP
GTSP storage
submerged combustion SPA
110
-------
The emission data from which the above NTU's were derived are based on
test data collected by EPA on those plants chosen for the best demon-
strated control systems.
These data generally show that the proposed standards of performance
for the various selected processes would appear on the lower end of the cost
effectiveness curve, Figure 4. From the standpoint of total costs, setting
a standard at higher levels, such as the requirement for SPA, would result in
very negligible incremental costs. The overriding factor would appear to be a
technical one. The pond water conditions represent the obvious constraint
to achievement .of high transfer units. Stripping of fluorides from feed
materials in the various processes in quantities over what constitutes
normal conditions would add to the inlet loadings to the scrubber and tend
to increase the emission levels. Particulate plugging of scrubber
packing would reduce effective absorption surface and efficiency.
In conclusion, the recommended standards and even standards at levels
higher than those recommended are not prohibited by cost.
IV. Economic Impact of Standards of Performance
A. General Discussion
According to the Clean Air Act, promulgation of Standards of Per-
formance for a designated pollutant would require States to formulate
implementation plans with emission regulations for existing sources
emitting fluorides in a manner similar to state implementation plans for
attainment of National Ambient Air Quality Standards (NAAQS).. As a
result of this legal mandate, the economic impact of the proposed standards
of performance may have farther reaching consequences than what the fol-
lowing analysis will show for new phosphate facilities. The economic
impact of emission limitations on existing.facilities that would result
from the promulgation of state standards is not in the scope of this anal-
ysis.
B. Total Pollution Abatement
Development Planning and Research Associates (DPRA) conducted an investi-
gation of the economic effects of water pollution abatement on the fertilizer
industry. They presented model plant investments for appropriate model plant
phosphate facilities. For example, for an integrated phosphoric acid plant com-
plex producing diammonium phosphate as its final product, capital investments
for double liming and primary clarification as specified water treatment are
111
-------
about $4,000,000 for a 900-TPD (P205) Plan* compared with some $40,000,000
total plant capital invested for phosphoric acid, ammonia, and solids pro-
cessing facilities. Reported annual water abatement costs (depreciation,
operating expense, maintenance costs) are approximately $3.00 per ton P20g
product. For the 500-T'PD model plant, abatement costs are an approximate $4.00
per ton PoOr. In terms of product price, these estimates would be approximately
r 2 5
$1.50 and $2.00, respectively.
DPRA indicated that increased abatement costs for diammonium phosphate
(and phosphoric acid, which is the intermediate product) could be passed on
to the consumer to the extent of $4.00 per ton product. This would allow the
more efficient (and larger size) producers to pay for the water abatement
equipment and maintain profitability at a rate equivalent to 8 percent or
better on their capital investment. According to DPRA analysis, the smallest
viable producer under this assumption would be a 170,000 ton per year plant
(235-TPD P205). New plants entering the fertilizer market would be larger
than this size because of increased investment requirements per unit capacity
and higher expected rate of return for attracting new venture capital into
this industry; hence, the rationale for the 5QTJ?TPD plant assumed as the
"small model plant" in this analysis for the standards of performance.
The price increases are expected for the following reasons. The
demand for fertilizer is fairly inelastic, cross elasticities between
competitive phosphate products notwithstanding. Second the price level
of all fertilizers is substantially lower than a decade ago, which has been
possible through improvements in technology in ammonia and wet-process
phosphoric acid processing. Thirdly, prices at the retail level are double
those at the production level. Hence, a $4.QO increase in DAP ( or 6 to
7 percent of the producers' sales'price)1 is only 3 percent at the consumer level.
With this background information on the ability of the fertilizer industry
to pass along costs above current price levels, the impact of abatement
under the standards of performance will be analyzed.
112
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C. Impact of Control Costs on Model Plants , ,
Table 14'presents a summary of annualized control costs for all the
processes under consideration for standards of performance. .The control
costs are presented on both a total product basis and a P205 basis.
Measure of control costs as a percent of sales is also presented for the
various products. Lastly, a column for impacts due directly to Federal
standards of performance is presented, that is, the difference in costs
between the proposed Federal standards of performance and an existing
stringent State regulation. The Florida regulations are deemed as the. most
stringent in the U.S. today and are assumed as the applicable State standard for
comparison with the Federal standards of performance. The actual allow-
able effluents for the various processes under the Florida regulation
are not comparable with those under the Federal standards of performance
because of differences in emission measurement techniques. Therefore,
model plant control configurations as presented in the tables in Section
III are assumed t.o comply with Florida's standards; any control less ef-
fective than the model plant control configurations will not comply with
Florida's regulation.
1. General Discussion of Plant Costs
As Table 14 shows, only triple superphosphate seems high in
magnitude of costs relative to fluoride emissions control cost for
other processes. The costs for granular triple superphosphate seem
prohibitive, in particular; however, as pointed out earlier, a com-
plex that can capably produce two products (DAP and GTSP) interchange-
ably with the same solids manufacturing facility can optimize utiliza-
tion of the owner's capital by operating his phosphoric acid plant at
full capacity and produce a product mix that will maximize his profits.
It is important to point out that basically the same emission control
equipment is used in both DAP and GTSP production.
If ammonia credits are excluded from the DAP recovery system, con-
trol costs for the average DAP plant (midway between 500-TPD and 800-TPD
P205) would be $1.60 per ton P205 for control of the reactor-granulator,
drier, and cooler process streams. An estimate of costs for control
113
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of similar process streams within the same plant for 6TSP production
would be $2.60 per ton P205. Hence, GTSP processing would cost $1.00
per ton more than DAP processing and require an additional $1.60 per
ton P205 for control of emissions during storage.
The costs of emissions control as shown in Table 14 for run-of-pile
triple superphosphate are low in comparison with GTSP; however, ROP-TSP
is an intermediate product sold to an NPK plant, which would have to
granulate a finished product from this intermediate material and incur
internal costs of emissions control in addition to the $1.58 per ton
P2C>5 incurred at the ROP-TSP processing level. Therefore, the NPK
plant operator would have to superimpose this incremental cost into his
overall cost structure, which would include his own internal control ex-
penses and the price of various phosphate substitutes (wet-process
phosphoric acid, DAP, GTSP) available to produce NPK fertilizers.
The costs for the submerged combustion process of producing super-
phosphoric acid represent the annualized costs for application of a ,.,
venturi-cyclone/packed scrubber system, that is a transfer of technology
from diammonium phosphate production. The costs are presumed for a
plant exhibiting no control although this is not quite the case as
evident from industry correspondence. On the other side of the coin,
the costs do not take into account engineering, design, testing, and
start-up for a system that has not been effectively demonstrated on a
submerged combustion plant.
2. Impact of Federal Standards over State Standards
Table 14 summarizes the cost differences between the Federal stand-
ards of performance and correspondingly stringent State standards. The
state of Florida requires new plants to employ control systems as effec-
tive as those assumed in the model plant configurations, with one excep-
tionthe submerged combustion process for producing superphosphoric
acid. Hence, one direct impact of the Federal standards of performance
would be the imposing of a universal cost penalty of some 28 cents per
ton P205 on the submerged process plant. As this amounts to only 0.13
percent of sales, there should be no impact.
115
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For diammonium phosphate and GTSP facilities in States other than
Florida, the Federal standards of performance would have a direct im-
pact. Secondary scrubbers required for DAP facilities in these areas
would cost an additional 43 cents per ton P205, storage facilities
would require fluoride control at a cost of $1.61 per ton P205 manu-
factured. Triple superphosphate facilities in areas other than
Florida probably have some fluoride emission control on the reactor,
but probably not on driers and coolers'in granulating facilities. Pri-
mary scrubbers would be required anyway for particulate emissions regu-
lations applicable under NAAQS. Secondary scrubbers for fluoride re-
moval on new GTSP plants in these areas might require an additional 64
cents per ton P205, in addition to the control costs for storage. As
some 80 percent of triple superphosphate production is confined to
Florida and will remain so in the future, the impact of the standards
of performance will be minimal on this portion of the industry.
Lastly, there will be no impact on wet-process phosphoric acid
plants or the vacuum evaporation production of SPA for emissions con-
trol imposed by the standards of performance. No impact is expected
for ROP triple superphosphate because of declining trends in production,
as cited earlier.
For plants built elsewhere than the state of Florida, some impact
due to the standards of performance may be expected for diammonium
and granular triple superphosphate for the reason that States other
than Florida have not required as stringent control of fluorides.
D. Impact of Standards of Performance on the Phosphate Industry
For most of the processes under consideration for standards of performance,
control costs associated with fluoride emission control are small. Assuming
trends as shown in Figure 3, price increases seem to be in prospect in the forsee-
able future. The reasons for this are as follows: (1) with elimination of
smaller, high cost operations, supply-demand relationships are improving for the
producers, (2) effects of dollar devaluation provide an assist for the domestic
industry by making exports more attractive to foreign markets, (3) internal
dynamics of the industry trending toward bulk blending and liquids production
which offer cost savings at the retailer level of the industry, and (4) in-
creased crop production increasing demand for fertilizers as result of a cur-
rent world-wide shortage of grain supplies. In general, cost increases in
production as a result of promulgating standards of performance on new sources
will be readily absorbed into increased prices at the consumer level.
116
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One area of possible impact would be GTSP production. As this product
competes with DAP for mixtures production, the higher costs under the
standards of performance on a unit ton (P2ฐ5) basis with respect to DAP
would be a deterrent for the producer who sold in the market bidding for
mixture materials. For a direct application of fertilizer to the soil,
this situation would not exist and the GTSP producer would pass costs along.
As discussed earlier, the effects of the dollar devaluation should
benefit agricultural fertilizer producers. As the magnitude of devaluation
far overshadows cost increases for fluoride emission control, no impact on
foreign trade is readily foreseen as a result of the promulgation of the
Federal standards of performance.
117
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1. Harre, Edwin A., Fertilizer Trends1969, National Fertilizer Development
Center, Tennessee Valley Authority, Muscle Shoals, Alabama.
2. Private Communication with William White, Fertilizer Institute, May 18,
1973.
3. Chemical Construction Company, unpublished report on a marketing survey
of the fertilizer industry, EPA Contract No. 70-156, 1971.
4. Initial Analysis of the Economic Impact of Water Pollution Control Costs
Upon the Fertilizer Industry, Development Planning and Research Associates,
A Report to the Environmental Protection Agency, Contract No. 68-01-0766,
November 1972.
5. "Soviet and Occidental Oil in Multibillion-Dollar Deal", New York Times,
April 13, 1973.
6. U. S. Industrial Outlook 1972 (With Projections to 1980), U. S. Department
of Commerce, Bureau of Domestic Commerce, April 1972.
7. Harre, E. A., Kennedy, F. M., Hignett, T. P., and McCure, D. L., Estimated
World Fertilizer Production Capacity as Related to Future Needs 1970 to
1975, National Fertilizer Development Center, Tennessee Valley Authority,
Muscle Shoals, Alabama.
8. Hardison, L. C., Air Pollution Control Technology in Seven Selected Areas,
Report prepared for Environmental Protection Agency under Contract No. 68-
02-0289 by the Industrial Gas Cleaning Institute, 1973.
118
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-450/2-74-019a
3. RECIPIENT'S ACCESSION-NO.
TITLE AND SUBTITLE BACKGROUND iNhORMAI ION HJk SiANUAKUb Uh
PERFORMANCE: PHOSPHATE FERTILIZER INDUSTRY
VOLUME 1. PROPOSED STANDARDS
5. REPQBT.DATE
1974
6. PERFORMING ORGANIZATION CODE
. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
. PERFORMING ORGANIZATION NAME AND ADDRESS
U.S. Environmental Protection Agency
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, N.C. 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
2. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF BEPOR.T AND PERIOD COVERED
FfnTl
14. SPONSORING AGENCY CODE
5. SUPPLEMENTARY NOTES
16. ABSTRACT
This document provides background information on the derivation of the standards of
performance for the phosphate fertilizer industry. Volume 1 provides a general
description of the facilities for which standards are proposed and provides the ration
rationale for the proposed standards of performance. Included is an analysis of the
economic impact of the standards on the industry. The proposed standards require
control at a level typical of well controlled'existing plants and attainable with
existing technology. To determine these levels, extensive on-site investigations were
conducted, and design factors, maintenance prartice, available test data, and the
character of emissions were considered.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control
c. COSATI Field/Group
Air Pollution
Pollution control
*Performance standards
*Phosphate fertilizer industry
*Wet-process phosphoric acid plants
*Superphosphoric acid plants
*Diammonium phosphate plants
*Run-of-pile triple superp
*Granular triple superpho"
*Granular triple superpho
hosphate plants
phate plants
iphate storage
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (ThisReport)'
Unclassified
>1. NO. OF PAGES
148
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
6PA Form 2220-1 (9-73)
119
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