EPA-340/1-84-013
Nitric  Acid  Plant  Inspection  Guide
                          Prepared by

                     PEDCo Environmental, Inc.
                       11499 Chester Road
                      Post Office Box 46100
                    Cincinnati, Ohio 45246-0100
                     Contract No. 68-01-4147
                       Task Order No. 44
                  EPA Project Officer: John R. Busik
                  EPA Task Manager: Kirk E. Foster
                         Prepared for:

                Stationary Source Compliance Division
              Office of Air Quality Planning and Standards
                U.S. Environmental Protection Agency
                     Washington, D.C. 20460

                         August 1984

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                                  DISCLAIMER
     This report was prepared by PEDCo Environmental, Inc., Cincinnati, Ohio,
under Contract No. 68-01-4147, Work Assignment No. 44.  It has been reviewed
by the Stationary Source Compliance Division of the Office of Air Quality
Planning and Standards, U.S. Environmental Protection Agency and approved for
publication.  Approval does not signify that the contents necessarily reflect
the views and policies of the U.S. Environmental Protection Agency.  Mention
of trade names or commercial products is not intended to constitute endorse-
ment or recommendation for use.  Copies of this report are available from the
National Technical Information Services, 5285 Port Royal Road, Springfield,
Virginia 22161.
                                      11

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                                   CONTENTS
Figures	,	iv
Tables.  .  .	vi
Acknowledgment	vii

     1.    Introduction. 	   1
               SIP requirements  	   2
     2.    NSPS Requirements and SIP Emission Limitations	   5
               NSPS requirements	   5
     3.    Process Description, Atmospheric Emissions, and
            Emission Control Methods	   8
               Process description	   8
               Atmospheric emissions	21
               Emission control methods 	  25
     4.    Startup, Shutdown, and Malfunctions	  51
               Startup	_,.	;	52
               Shutdown	-	53
               Malfunctions	54
     5.    Process Control  System and Emission Monitoring
            Instrumentation	  56
               Process monitoring instrumentation 	  56
               Emission control instrumentation . 	  59
               Emission monitoring instrumentation	63
               Chemiluminescence	 .  67
               Electrochemical	70
     6.    Performance Tests and Continuous Monitor Performance
            Evaluations	73
               Performance tests	  73
               Pretest arrangements 	  73
               Observing performance tests	74
               Continuous  monitor performance evaluation.  .......  75
     7.    Inspection Procedures 	  77
               Plant inspection	-	77
          ~    Estimation  of emissions from nitric acid plants	80

References	85

Appendices

     A.   NSPS regulations	„	87
     B.   EPA methods 1, 2, 3, and 7 and performance
            specification  2 	 .....  	 109
     C.   Glossary of terms	157
                                      iii

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                                    FIGURES
Number                                                                   Page

  1       Basic ammonia oxidation process 	    9

  2       Conversion of ammonia to nitric oxide as a function of
            temperature and gas velocity	   12

  3       Effect of pressure on the oxidation of ammonia at
            different temperatures	   12

  4       Rate constant	   13

  5       Rate of oxidation of ammonia converter products at 100°C. .  .   13

  6       Minimum time for absorption-in water of nitrogen oxides
            from ammonia oxidation	   15

  7-      Flow diagram of a typical 120-ton-per-day nitric acid
            plant using the atmospheric pressure process	   16

  8       Flow diagram of a typical 120-ton-per-day nitric acid
            plant using the pressure process	   18

  9       Flow diagram of a typical 120-ton-per-day nitric acid
            plant using the combination pressure process	   22

 10       Acid plant incorporating catalytic reduction for
            NOV abatement	   28
              A
 11       Extended absorption system for NO  emissions control	   33
                                                                                   4
 12       NSPS test results of NO  emissions at nitric acid plants. .  .   34
                                 A

 13       Flow diagram of the MASAR process	   39       •«-

 14       Process flow diagram for the Goodpasture process	   41

 15       Schematic flow sheet of the CDL/VITOK NOV removal process .  .   44
                                                  A

 16       Two-bed Purasiv N process (Vessel A under adsorption and
            Vessel B under regeneration heating) for control of NO
            in nitric acid plant tail gas	   46

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                              FIGURES (continued)

Number                                                                   page
 17       The Bo "line NO  recovery system	•	    47
                      X
 18       Instrumentation flow diagram for ammonia oxidation process.  .    57
 19       Catalytic reduction unit instrumentation flow diagram ....    60
 20       Molecular sieve adsorption unit instrumentation flow
            diagram	    62
 21       Nondispersive ultraviolet analyzer	    64
 22       Nondispersive infrared analyzer 	    66
 23       Variable wavelength NDIR analyzer 	    68
 24       Gas cell  correlation spectrometer analyzer	    68
 25       Single-beam,  dual  wavelength NDIR	    69
 26       Chemiluminescence  analyzer ".	    71
 27       Electrochemical  analyzer	„	    72
 28       Production rate vs.  air feed rate	    81
 29       Conversion of NO  tail  gas concentration  to mass emission  .  .    82
                          A
 30       Ammonia  feed  rate  vs.  production  rate	    84

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                                    TABLES
Number

  1

  2


  3

  4

  5


  6


  7
                                                               Page
Summary of SIP requirements specific to nitric acid plants. .

Typical compositions of tail gas emissions for nitric
  acid plants with and without catalytic combustors 	
23
NO  control methods for nitric acid plants	   26
  /\

Typical nitric acid plant tail gas emission compositions. .  .   27

Operating conditions for treating nitric acid plant
  tail gas by catalytic reduction	   31
Compliance test results for-nitric acid plants subject
  to the NSPS since the 1979 review 	
Excess emissions data from extended absorption nitric
  acid plant operations at CF Industries, Donaldsonville,
  LA	
                             *

Design specifications for the Bolme NOX recovery process
  applied to a new 220-metric-ton-per-day medium-pressure
  nitric acid plant 	 	
35
                                                                          36
                                                                          48

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                               ACKNOWLEDGMENT
     This report was prepared for the U.S. Environmental Protection Agency by
PEDCo Environmental Inc., Cincinnati, Ohio.  Mr. Kirk Foster was the EPA Task
Manager.  The principal author was Mr. Gary Saunders.  This report was based
on an original manuscript by Mr. Edward Wyatt.

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                                   SECTION 1
                                 INTRODUCTION

     New Source Performance Standards (NSPS) have been promulgated by the
U.S. Environmental Protection Agency (EPA) for nitric acid (HN03) plants pro-
ducing weak nitric acid (30 to 70 percent strength) as authorized under
Section 111 of the Clean Air Act (42 U.S.C. Section 1857 et sej_.), as amended.
Under Section 111, the Administrator of EPA is authorized to develop and
promulgate standards of performance for new stationary sources that are con-
sidered to contribute significantly to air pollution.  The nitric acid stand-
ards of performance that were promulgated December 23, 1971, apply to all
nitric acid plants constructed or modified after August 17, 1971.
     Each State agency may develop its own enforcement program for NSPS sources
within its jurisdiction.  If the program is determined to be adequate, the
State agency may be delegated authority to oversee enforcement of the NSPS.
This authority would be granted over all new and modified sources subject to
a particular NSPS regulation, provided the emission limitations adopted at the
State level for the NSPS sources are at least as stringent as the Federal NSPS
standards.
     Effective implementation and enforcement of the NSPS program depends
primarily on the inspection program used to ensure compliance with the appli-
cable emission limitations.  For nitric acid plants, this requires a mix of
the recordkeeping requirements and periodic field surveillance.
     The purpose of this manual is to aid in the development of uniform evalu-
ation procedures to determine compliance with the NSPS requirements for nitric
acid plants.  This manual discusses the operating principles for nitric acid
plants and the control techniques that may be employed to meet emission limi-
tations and describes inspection techniques that may be used to determine
compliance with the regulatory requirements.
     This manual is divided into 7 sections.  Section 1 is the introduction.
The other six sections are summarized as follows:

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     o    Section 2 - This section briefly outlines the requirements of the
          NSPS for nitric acid plants and those of the State Implementation
          Plans (SIP's).  It is designed to aid and familiarize enforcement
          personnel with the regulations applicable to nitric acid plants.

     o    Section 3 - This section is intended to help familiarize personnel
          with the processes and instrumentation involved in the production
          of nitric acid, the control equipment that may be applied to reduce
          emissions, and the level of emissions or degree of control that may
          be expected from each type of control equipment.

     o    Section 4 - This section discusses some of the effects of startup,
          shutdown, and malfunctions on the emissions from nitric acid plants
          and some of the steps that may be taken to reduce or minimize their
          impact.

     o    Section 5 - This section discusses the operating parameters that
          should be observed during the performance test for demonstration of
          compliance.  In addition, this section discusses the continuous
          emission monitoring testing requirements.

     o    Section 6 - This section discusses recordkeeping requirements, data
          required in these records, emission monitoring techniques, and methods
          for evaluating performance ajid excess emission reports.

     o    Section 7 - This section discusses inspection techniques that may
          be used by enforcement personnel  to determine compliance with
          applicable limitations during routine field surveillance and followup
          inspections.

     This manual also contains three appendices:

          Appendix A:  Nitric Acid NSPS Regulations

          Appendix B:  EPA Methods 1, 2, 3, and 7

          Appendix C:  Glossary of Terms.
1.1  SIP REQUIREMENTS

     Existing nitric acid production facilities not subject to NSPS are subject
to the emission limitations contained in the SIP's.  Most States limit the

emissions from nitric acid plants through a general process weight rate regu-
lation.  The following States, however, limit the emissions as a result of
regulations that are specific for nitric acid plants:

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               Al abama
               Arizona
               Connecticut
               Georgia
               Kentucky
               Louisiana
               Maryland
               Minnesota
               Nebraska
North Dakota
Pennsylvania
South Dakota
Tennessee
Texas
Virginia
Washington
Wisconsin
Wyomi ng
     Table 1 summarizes the SIP limits for the States that have specific
requirements for nitric acid plants.   The nitrogen dioxide (N02) limits from
existing nitric acid plants generally range from 3.0 to 5.5 Ib/ton of 100
percent acid produced.

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       TABLE  1.   SUMMARY OF SIP REQUIREMENTS SPECIFIC  TO
                          NITRIC ACID  PLANTS
State
Alabama
Arizona
Connecticut
Georgia
Kentucky
Louisiana
Maryland
Minnesota
Nebraska
North Dakota
Pennsylvania
South Dakota
Tennessee
Texas
Virginia
Washington
Wisconsin
Wyoming
Pollutant
N02
N02
N02
N02
N02
N02
N02
N02
N02
N02
N02
N0?
N02
N02
N02
N0?
NO
N02
Limit, Ib/ton of 100% acid
5.5
^ g3,b,C g gb,C,d
5.5
25.0e'f 3.0f>g
3.0f,h,1,j 5<81,k
6.5
3.0
3.0Ctl 5.5c'm
5.5
3.0 ' )J
5.5
_J,K
3.0c'n 5.5C'°
600P
5.5
5.5
3.0b
3.0b'C'h 5.5b'c'k
aPlant under construction or in production on  or after August 20, 1973.
bWeak acid (30-70%  in strength).
cMaximum 2 hour average.
 Plants under construction or in production before August 20, 1973.
ePlants constructed before January 1, 1972.
 Must be equipped with a continuous NOX monitor and recorder or an alternate
 system approved by the Director.
9Plants constructed after January 1, 1972.
 Plants under construction or in production before August 17, 1971.
10pacity not to exceed 10 percent.
•'Owner or operator  must record the daily production rates and hours  of operation.
 Plants under construction or in production before August 17, 1971.
 Plants under construction or in production on or after February 1,  1972.
'"Plants under construction or in production before February 1, 1972.
"Plants under construction or in production on or after April 3, 1972.
°Plants under construction or in production before April 3, 1972.
''Parts per million  by volume.
1

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                                   SECTION 2
                NSPS REQUIREMENTS AND SIP EMISSION LIMITATIONS

2.1  NSPS REQUIREMENTS
     Standards of Performance for new nitric acid plants producing weak nitric
acid were published and promulgated in the Federal Register on December 23,
1971.  The regulation (see Appendix A) applies to all plants producing 30 to
70 percent strength nitric acid that are constructed or modified after
August 17, 1971.  Designated Subpart G of the NSPS, the regulations are sum-
marized below.  In addition to the requirements of Subpart G, nitric acid
plants subject to NSPS are also subject to the monitoring and recordkeeping
provisions of Subpart A.
     The current emission standards were reviewed in 1979 and 1984 by EPA to
determine if any changes in the current emission limitations were warranted.
No revisions to Subpart G and the emission, standards are proposed at this
time.
2.1.1  Emission Standards
     The allowable emissions limits for nitrogen oxides and opacity are stated
in Section 60.72.   Emissions of nitrogen oxides are limited to less than 1.5 kg
(expressed as N02) per metric ton of nitric acid produced (3.0 Ib/ton).  Nitric
acid production is expressed as 100 percent nitric acid.  Opacity is limited
to 10 percent or less.
2.1.2  Performance Testing
     Determination of compliance is made according to performance tests con-
ducted according to Section 60.8 of the NSPS.   This section requires the plant
operator to provide a written report of the tests that must be conducted at
conditions representative of the normal  operating conditions.   Testing for
nitrogen oxides is conducted using Method 7 and the criteria of Methods 1 and
2.

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     Performance tests are required to be conducted within 60 days of achieving
maximum production rate, but not longer than 180 days after initial startup.
The EPA must receive at least 30 days notice prior to all performance tests.
In addition, the plant owner or operator is responsible for providing the
following performance testing facilities:
     1.   Sample ports adequate for applicable test methods,
     2.   Safe sampling platform(s),
     3.   Safe access to sampling platforms, and
     4.   Utilities for sampling and testing equipment.
Tests in addition to the initial performance test may be required from time-
to-time by the Administrator as authorized under Section 114 of the Clean Air
Act.
2.1.3  Stack and Process Monitoring
     Nitric acid production facilities^are required to install, operate,  and
maintain a continuous emission monitor for the measurement of nitrogen oxides
(NOX).  Because the units of the emission standard are expressed as N02»  the
emission monitor should display the output as N02-  Requirements for these
continuous monitoring systems are outlined in Section 60.73, Section 60.13,
and Appendix B of 40 CFR 60 - Performance Specification 2.
     The monitoring system is required under Section 60.13 to meet the require-
ments of Performance Specification 2.  This performance evaluation is required
to be conducted within 30 days of any performance test required under Section
60.8 and at any other time it is deemed necessary by the Administrator.
     In addition to operating and maintaining the continuous monitor, the
plant operator must perform zero and span checks on the monitor at least  once
every 24 hours.  The plant operator may zero and span the instruments at  more
frequent intervals, if desired.
     The plant owner or operator must record daily production rates and hours
of operation.  A conversion factor established during the performance test
(Section 60.8) or performance evaluation (Section 60.13) to convert from  ppm
NOp to units of the standard shall be used to determine excess emissions.
These excess emissions are calculated as the arithmetic mean of any three

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contiguous 1-h periods as measured by the continuous monitoring system exceeding
the standard in Section 60.72(a) (1.5 kg/metric ton).
2.1.4  Recordkeeping and Reporting
     The recordkeeping and reporting requirements for nitric acid plants  subject
to NSPS are outlined in Section 60.7.  Enforcement personnel should be particu-
larly aware of the requirements of Section 60.7(b) and (c).   Section 60.7(b)
requires the plant owner or operator to maintain records of  any startup,
shutdown, or malfunctions that occur at an affected facility, any malfunction
of control equipment, or any periods in which the continuous monitor is in-
operative.  In addition, Section 60.7(c) requires the plant  owner or operator
to submit a quarterly excess emission report postmarked by the 30th day fol-
lowing the end of each calendar quarter.  The excess emission report must
include the identification of any periods of excess emissions, including
excess emissions that occur during periods of startup, shutdown,  and mal-
functions.  The report must also identify the nature and cause of the mal-
function and the corrective action taken with respect to the malfunction.  In
addition, the excess emission report must include the date(s) and time(s) of
any periods when the continuous monitor was inoperative (except for daily zero
and span calibration checks) and the nature of repairs or adjustments necessary
to restore monitor operation.
     The plant owner or operator must maintain a record, in  a manner suitable
for inspection, of all monitoring data, maintenance records, performance
tests, continuous monitor performance.evaluations, and excess emission reports
for a period of two years.  These requirements are outlined  in Section 60.7(d).

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                                    SECTION 3

                   PROCESS  DESCRIPTION, ATMOSPHERIC EMISSIONS,
                         AND  EMISSION CONTROL METHODS
3.1   PROCESS  DESCRIPTION
      Presently all weak nitric acid is manufactured by the ammonia oxidation
process  (AOP).   In general, this process involves the oxidation of ammonia by
air  (oxygen)  with subsequent cooling and water absorption of the reaction
                             1 2
gases to produce nitric acid.     A majority of AOP plants are located at or
near ammonia  plants, and the product acid is used in the production of nitrates.
Thus, ammonium nitrate plants are usually located in the same production
complex with  ammonia and nitric acid plants.
      Earlier  processes, based on the reaction of sulfuric acid on saltpeter
or the passing of air through an electric arc, have been replaced and antici-
pated breakthroughs for the direct combination of nitrogen and oxygen in
•nuclear reactors has not taken place.  Also with the new generation of ammonia
plants cutting the cost of ammonia in half, it appears unlikely that other raw
materials for nitric acid would become competitive in the near future and
therefore, the ammonia oxidation process will remain the main source of weak
nitric acid production.
3.1.1  Basic  Process Description of AOP
      Despite  many variations in operating details among the plants producing
nitric acid,  three basic steps are common to all:  1) oxidation of ammonia to
nitric oxide, followed by 2) oxidation of nitric oxide to N02, and finally 3)
absorption of N02 in water to produce nitric acid with the release of additional
nitric oxide.
     The essential equipment and flow sequence in AOP are illustrated in
Figure 1.   Ammonia vapor is mixed with preheated air and passed over a
catalyst, where the ammonia is oxidized to nitrogen oxide.  The hot reaction
gases are cooled in waste heat boilers (for heat recovery and steam generation)
and  heat exchangers, permitting the nitric oxide to be oxidized to N02 by the
                                      8

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oxygen remaining  in the  process gas stream.  On cooling, water condenses and
some N02 dissolves to form weak nitric acid.  The process gas then flows to an
absorber where the nitric acid is formed by absorption of N02>  Nitric oxide
is released in the absorption of N02 to form nitric acid and the nitric oxide
passes through the absorber column.  The weak nitric acid produced in the
cooling and N02 formation step is introduced into the absorber at the point in
the vertical tower where the acid in the tower is the same concentration as
the nitric acid that is produced.  The balance of the oxygen (bleach air)
required to oxidize the released nitrogen oxide is introduced into the bottom
of the absorber.  The tail gas leaving the top of the absorber contains resi-
dual nitrogen oxides, a low percentage of oxygen, and water vapor with the
balance of the material being inert nitrogen.  The nitric acid produced is
withdrawn from the bottom of the absorber.
     The chemical reactions involved in AOP are exothermic and the heat pro-
duced is used to generate process steam superheat and/or to evaporate the
ammonia and to heat process air.  The tail gas is typically reheated and
expanded through a turbine to recover "part of the compression power.   Many
plants are self-sustaining after they are started by using auxiliary energy
             .                                            \
sources.
     In summary, the essentials of an ammonia oxidation nitric acid plant are:
     1.   Converter or oxidation section where the ammonia vapor and  air are
          mixed and reacted catalytically to oxidize the ammonia.
     2.   Cooler-condenser section where the nitrogen dioxide is produced by
          cooling the reaction gases and weak nitric acid is  formed.
     3.   Absorber section where the cool  NCL is  absorbed in  water to form the
          product nitric acid.
3.1.2  Basic Process Chemistry
     Knowledge of the basic chemistry is necessary to understand the  commercial
plant designs  where the pressure and temperature  characteristics of AOP chemistry
are most efficiently used.   The chemistry used in AOP for the manufacture of
nitric acid involves the following three reactions:
                                      10

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 4  NH3  +  5  02 + 4  NO +  6
•2  NO  +  02 -»•  2  N02
 3  N02  +  H20 •*  2  HN03 +  NO
                                                                      (1)

                                                                      (2)

                                                                      (3)
                                           4
The first reaction (1) is a heterogeneous gas-phase catalytic reaction.   The
primary oxidation of ammonia to nitric oxide,  with a platinum alloy catalyst,
is carried out at approximately 1500° to 1750°F, with a very short contact
time.  This reaction has been extensively studied, but no completely satis-
factory reaction mechanism has resulted.  The  reaction rate is very rapid
with a 95 percent or more yield of nitric oxide under a fairly wide range of
conditions.  In addition to this main reaction, other side reactions are
defined and discussed in Reference 1.
     The results of earlier experiments (Figure 2) show the relationship
between contact time (inverse of gas velocity) and catalyst temperature.
These data indicate that the conversion of ammonia to nitric oxide can be
maximized for each gas velocity by the optimum catalyst temperature.  This
reaction is so rapid that the percent conversion ultimately depends on the
rate at which ammonia and oxygen can be contacted with the catalyst surface.
     Figure 3 shows the effect of pressure on the ammonia-oxidation reaction.
Increased pressure reduces the maximum amount of conversion that can be
obtained for a given temperature and contact time.
     The second reaction  (2) is a homogeneous, noncatalytic, gas-phase reaction
between nitric oxide and oxygen to produce N02-  This is not only a slow
reaction, but it  is also  strongly dependent on temperature.  This reaction is
unique in that the reaction rate decreases with increasing temperature as
shown in Figure 4.  This  reaction is also strongly dependent on pressure.
Figure 5 shows that increasing pressure causes a higher percent oxidation of
nitric oxide and  also reduces the reaction time necessary to reach maximum
conversion in the process.
     The third reaction  (3) is a heterogeneous equilibrium reaction and con-
sists of the absorption of  N02 in water to form nitric acid.  The rate of this
reaction is controlled by the  following steps:
        11

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                              V-GAS VELOCITY,
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             700        800

                 TEMPERATURE, °C
             900
1000
 Figure 2.   Conversion  of  ammonia  to  nitric oxide as a function of
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          100
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                           TEMPERATURE, °C
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Figure 3.  Effect of pressure on the oxidation of ammonia at
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                              12

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                             TIME IN SECONDS
  Figure 5.  Rate of oxidation of ammonia converter products at 100 C.i


                                   13

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     1.   The oxidation of nitrogen oxide to NCL in the gas phase.
     2.   The physical diffusion of the reacting oxides from the gas phase
          to liquid phase.
     3.   The chemical reaction in the liquid phase.
Both steps 1 and 2 proceed more rapidly at low temperatures than high tempera-
tures, while step 3 is retarded by low temperature.  Because step 3 is inherently
rapid even at low temperatures, it tends not to be a controlling factor in the
formation of nitric acid.
     The equilibrium conditions that determine the maximum strength of the
nitric acid are not appreciably affected by temperature, but are favorably
affected by increased pressure, which makes the production of higher acid
strengths possible.  Figure 6 shows the effects of elevated pressure on the
overall absorption rate.
     Although the efficiency of AOP declines slightly with increased operating
pressure, the nitric oxide oxidation and the absorption reaction rates are
greatly increased by increased pressure.
3.1.3  Commercial Processes for Weak Acid Production
     Before the development of stainless iron and steel alloys in the 1920's,
the only material suitable for absorption of nitric acid were stoneware and
acid-proof brick.  Because this limitation prevented operations at pressures
greater than one atmosphere, very large-sized equipment was required and
nitric acid strength was limited to approximately 50 percent concentration.
With the advent of acid resistant alloys capable of operating at higher pres-
sures and the desirability to produce higher strength acids, industry decided
                                                                    i o "5 Q
to construct pressure or combination (dual-pressure)- process plants. '''
     A description of each type of process for weak acid production is pre-
sented in the following sections.
3.1.3.1  Atmospheric Pressure Process-
     It is very improbable that any new atmospheric process plants will  be
built.  Although some of these early plants are still  in existence, they are
generally used only in a standby capacity.  The atmospheric pressure process
shown in Figure 7 is presented simply as a basis for understanding the
other more common processes, because they can be considered derivatives
of the atmospheric pressure process.

                                     14

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        10% NH3 AT CONVERTER, 5% i
CURVE A -'8 ATMOS.,  92% CONVERSION* 50%  NHO
                                         IN EXIT GAS
                                                  IN CONOENSATE
     CURVE B -
        100
          40
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          1 ATMOS., 96% CONVERSION,  25% NHO,  IN  CONDENSATE
                                   I
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                100   200   300   400    500
                         TIME IN SECONDS
                                        600  700
Figure 6.   Minimum time  for absorption  in water of nitrogen oxides
                     from ammonia  oxidation.1
                               15

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     In the atmospheric process, ammonia oxidation and conversion  to  nitric
acid of the resultant nitrogen oxides is carried out at pressures  near  atmos-
pheric.  Briefly, this process includes the following steps.
     Step 1.  Liquid ammonia is evaporated and the resulting  gas  is collected
and pumped by a fan to a mixer where filtered air is added.   The  resultant
mixture of ammonia and air, usually containing from 9.5 to 11 percent ammonia,
is brought in contact with the catalyst, where the ammonia is oxidized  to
form nitrous oxide and water.
     Step 2.  After leaving the catalyst, the nitrous gases are cooled  in
the air preheater and the waste heat boiler where nitric acid is  oxidized to
NOp.  The gases are further cooled in a series of cooler-condensers  in  which
nitric acid begins to form.  The cooler-condenser will produce an  acid  con-
taining approximately 20 to 22 percent nitric acid (HNOo). The condensate
formed during this step is conveyed to the absorption section of  the  plant
where it is passed through a series of absorption towers.  The final  product
(45 to 52 percent HNOg) is drawn off from the last absorption tower.
     Considering current technology, the main advantages of atmospheric-type
plants are the lower platinum consumption and higher conversion efficiency
from ammonia to nitric oxide in the burner.  However, the improvement of
platinum filter design, the efficiency of pressure burner units,  and  the
greater absorption efficiency of pressure processes in the production of
increased strength acid, make pressure processes much more economically
attractive.
     It should be noted that in the atmospheric pressure process,  the low
oxygen content of the tail gas and the low absorption efficiencies of NOg
require a large number of towers to reduce the nitric oxide content of  the
tail gas to the acceptable figure of approximately 0.2 to 0.3 percent nitric
oxide.
3.1.3.2  The Pressure Process—
     The typical pressure process plants shown in Figure 8 are the result
of technical advances in nitric acid production since the 1940 through  1950
time period.  During World War II many of the pressure process plants were
built to manufacture munitions, but these facilities did not  have catalytic
reduction units or turbine expanders.  The first pressure-type plants operated
                                      17

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at approximately 80 to 130 pounds per square inch absolute (psia) and had
reciprocating compressors that recovered about 40 percent of the compressor
power.  In the 1950's the development of high temperature designs for gas
turbines permitted improved power recovery and the use of centrifugal compres-
sors permitted the production of air hot enough to be used directly in the
converter.  A catalytic reduction unit was added to the process to further
improve power recovery.  By heating the tail gas to approximately 1250°F
before expansion, the catalytic reduction unit has resulted in the recovery
of all the power required for air compression.  The side effect of reducing
the nitrogen oxide concentration in the tail gas was an added advantage as
air pollution regulations have been broadened in recent years to include the
control of nitrogen oxide emissions.
     The pressure process, in which both ammonia oxidation and conversion of
the resultant nitric oxides are carried out at greater than atmospheric
pressure, consists of the following steps.
     Step 1.  Liquid ammonia is evaporated either directly from the heats of
formation of nitrous gases or nitric acid, or indirectly by steam generated
from the recovery of the heats of reaction in waste heat boilers.
     Step 2.  Air is compressed to a pressure that varies somewhat from plant
to plant but in the most recent plants, is approximately 110 pounds per square
inch gauge (psig).  In large capacity units, the compressor used is generally
of the centrifugal type.
     Step 3.  The streams of filtered ammonia gas and air mix and the mixture
then goes to the burner.  Air, delivered by centrifugal compressors,  is usually
hot (450° to 500°F) enough to avoid preheating.  If reciprocal-type compressors
are used, however, the air must be preheated.  In both cases, the temperature
of the air before being mixed with ammonia must be approximately 500°F.   In
the burner itself, the temperature at the catalyst is maintained at approxi-
mately 900°C (1,650°F).
     Step 4.  If power recovery, is adopted, the gas leaving the burner passes
through a heat exchanger to lower the tail gas temperature to approximately
950°F.  The burner gas is then cooled at a pressure of 150 to 225 psig.   A
catalyst recovery filter is usually installed at the cold end of the boiler.
Finally, the gas is cooled in a cooler-condenser in which most of the water
produced by the oxidation reaction is removed as 40 to 45 percent nitric acid.

                                      19

-------
     Step 5.  The gas then flows into the absorption system where the oxidation
of NO to N02 is then completed and these oxides are absorbed in water to form
nitric acid.
     Step 6.  Weak acid from the condenser is introduced at an appropriate
point in the absorption system.  The absorption system proper may consist of
one bubble-cap tray or of a cascade of absorption drums, each equipped with
one tray and several coolers.  In the bubble-cap tray tower, the coolers are
placed directly on the trays around the bubble-caps.
     Step 7.  The product acid is bleached in the lower section of the
absorption tower itself or in a separate bleacher.   The acid produced (57
to 60% HNOg) does not contain more than 0.05 percent nitrous acid.
The overall  efficiency of absorption under pressure is sufficiently high (98
to 99%) to permit the elimination of alkali scrubbers.
     The main advantage of the pressure type plant when compared with the
atmospheric pressure type plant of the same efficiency is a significant reduc-
tion in equipment volume required for oxidation, heat exchange, and most
importantly, absorption.
3.1.3.3  Combination Process—
     In the combination process for nitric acid production, ammonia oxidation
takes place near atmospheric pressure while absorption occurs at pressures
much higher than atmospheric pressure, thereby using the optimum economic
efficiencies for both conversion and absorption.  The oxidation of ammonia
typically occurs at pressures from atmospheric to 50 psia.   The resulting
nitrogen oxides are then cooled and compressed to approximately 50 to 215 psia
for absorption.  The lower conversion (oxidation) pressure  gives the highest
conversion efficiency at a lower operating temperature (1500°F) which prolongs
the life of the catalyst by a factor of 3 to 5 over the pressure process. The
high pressure absorption, using smaller equipment,  gives a  high absorption
efficiency and higher strength acid.  This process, popular in Europe, is
finding increased popularity in the United States.   Increasing cost for elec-
trical power, catalyst material, and ammonia, coupled with  increasingly
stringent nitrogen oxide (NO ) emission regulations are causing this type of
                            A
plant to be given increased consideration.
                                     20

-------
     In this type of plant (Figure 9),  the nitrous gases  leaving the atmos-
pheric oxidizer pass through condensers where they are cooled to a temperature
close to that of the cooling water.  A  stainless steel turbo-compresser
compresses gases to a pressure that may vary from 50 to 215 psig according
to the type of plant.
     Because these nitrous gases contain an excess of air,  this  compression
helps considerably in completing the oxidation of NO to I^ and  N^O*.   The
compressor is followed by a condenser from which 33 to 42 percent nitric acid
is withdrawn.  This acid is pumped to the absorption tower and introduced at
the level in the tower that corresponds to the same acid  strength.
     The acid condensed prior to compression is added at  the appropriate
points in the absorption system.  In order to recover the power  consumed for
air compression, the tail gas leaving the absorption system is preheated by
heat exchange with the hot nitrous gases leaving the ammonia burner before
being released to the atmosphere by an  expander mounted on the shaft of the
gas compressor.
     This combined scheme claims the advantage of higher  ammonia oxidation
yield and lower platinum loss, added to higher absorption efficiency and power
recovery.

3.2  ATMOSPHERIC EMISSIONS
     Ammonia oxidation nitric acid plants have one point  of emission,  the
tail gas stack.  The tail gas from nitric acid plants contains no particulate
matter, and the temperature of the tail gas is high enough to prevent any
mist formation as a result of water vapor condensation.  Typical compositions
of tail gas emissions from plants operating with and without controls  are
presented in Table 2.
                                     21

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 TABLE 2.   TYPICAL COMPOSITIONS OF TAIL GAS EMISSIONS FOR NITRIC ACID PLANTS
                    WITH AND WITHOUT CATALYTIC COMBUSTORS9
Tail gas emissions
Nitrogen oxide, ppm
Nitrogen dioxide, ppm
Oxygen, percent by volume
Temperature, °F
Pressure, psig
Absorber exit
1000-2000
1000-2000
2-4
90-100
85-95
Catalytic
combustor exit
40-350
0-350
0-1.5
1000-1300
75-90
The NSPS specify that NO  emissions must not exceed:   1) 3.0 Ib of nitrogen
                        /\
oxides expressed as NO^ per ton of nitric acid (100 percent) produced (3-h
average) and 2) a plume opacity of 10 percent.  The emission limit of 3.0 Ib
of nitrogen oxides per ton-of acid produced is equivalent to approximately
209 ppm (0.0209 percent by volume) concentration of nitrogen oxides in the
process tail gas in a typical plant.
     Nitric acid plants are primarily designed to achieve a specified production
rate (tons of nitric acid in a water solution) using a given quality of ammonia
feed.  Other considerations necessary for the design of a plant are the speci-
fications for certain auxiliary utilities such as cooling water, condensate
quality water, boiler feed water, electricity, and process instrumentation.
     When a plant is designed for a certain production rate, acid strength,
and emission rate (Ib NO  per ton 100 percent acid), an increase in the pro-
duction rate and/or acid strength will typically increase the NO  emission
                                                                /\
rate.  This is due to the fact that increasing the production rate decreases
the time available for the oxidation of the nitrogen oxide to N02, decreases
the absorption of the N02 resulting in efficiency losses and overloading of
the catalytic reduction unit (if used), and increases the amount of NOX
emissions per ton of acid produced.  On the other hand, if the plant is
operated below the production rate and/or the acid strength is reduced, the
time available for reactions and absorption is increased and a reduction of
NO  emissions would be expected.
                                     23

-------
 3.2.1  Types of Emissions
 3.2.1.1  Nitrogen Oxides--
      Nitrogen oxide (NOV) emissions  consist  mainly  of  NO and  N00 and are
                        «                                       c.
 emitted to the atmosphere in  the  absorber  tail  gas  after it leaves  the ex-
 pander and final  heat exchangers.  These emissions  vary with  the plant design,
 maintenance practices,  production rate, and  absorber efficiency.  Absorber
 efficiency can be increased by  higher  pressure  and  Tower temperature.  This
 will  result in lower NO emissions.  Emissions  of NO   from well -maintained
                        *                           x
 and properly operated nitric  acid plants without catalytic combustion devices
 or extended absorption  average  from  2000 to  3000 ppm.  However, NO  emissions
 as low as  1000 ppm have been  reported  at many existing plants.  Catalytic
 combustion devices can  reduce the  N02  content significantly by  reducing the
NO to
            Catalytic combustion can also aid  in energy recovery.  Because N0
 is  the  cause of  the reddish-brown plume that may be observed, the effectiveness
 of  the  catalyst  combustion process  is evidenced by the colorless tail gas
 stack conditions.
 3.2.1.2 Acid Mist--
     Acid mist emissions do not occur from a properly operated plant.  Acid
 mist is present  in the gases leaving the absorber.  These emissions, however,
 are largely removed by centrifugal  collectors or mesh mist collectors before
 the gases are heated prior to entering the catalytic combustor or turbo-
 expander.  Trace quantities of acid mist present in the tail gas are vaporized
 as  the  gas is reheated.
 3.2.1.3  Visible Emissions--
     Visible emissions of a reddish-brown color occur from uncontrolled nitric
 acid plants due to the N02 in the exit gas.  The opacity of stack gases varies
 with the N02 content and the stack diameter.  The approximate visible threshold
concentration of N02 is given by the suggested equation:
                                                        10
                                 Co =
                                      2400
where
     d s stack diameter in inches
    Co - visible concentration, ppm
                                      24

-------
Thus for a 12-inch diameter exit stack,  a visible emission would occur at an
NOp concentration of approximately 200 ppm.   With larger diameter stacks, the
visible plume would occur at lower NOp concentrations.   The acid production
system and storage tanks are the only significant sources of visible emissions
at most plants.  The amount of emissions from storage tanks is  considerably
less than the emissions from the stack.  '
3.2.1.4  Reducing Compounds—
     Through the application of catalytic reduction systems, the NO  abatement
                                                                   A
of nitric acid plant tail gas can result in  the production and  emission of
hydrocarbons, carbon monoxide, and other reducing compounds. These compounds
are produced as a result of the reducing atmosphere in  the catalytic system.
Although little data are available on the subject, it is expected that for a
given system, reducing compounds are produced in inverse proportion to NO .
                                                                         /\
The relevance of these secondary emissions is not well-documented.   To date,
no attempt has been made to control  the  release of reducing compounds to the
atmosphere.

3.3  EMISSION CONTROL METHODS
     After the promulgation of the 3.0 Ib of NO  per ton of acid NSPS in
                                               X           —
1971, catalytic reduction was the primary NO  abatement system  installed on
                                            /\
new nitric acid plants until 1975.  With the developing natural  gas shortage
in 1975 and the advent of a proven alternate NO  control technology (extended
                                               /\
absorption), the entire nitric acid NO  control situation was radically changed.
                                      X
From 1975 through mid-1978, 50 percent of new nitric acid plants employed the
extended absorption process for NO  control.  Since 1979, all but one of the
                                                                           11
new or modified nitric acid plants were  designed to use extended adsorption.
Although the extended absorption process can achieve the NSPS level  of NO
                                                                         /\
control, it is not able to reduce emissions  to the same level obtainable with
catalytic reduction.  Other methods used for NO  control on nitric acid
                                               X
plants include wet scrubbing, chilled absorption, and molecular sieve adsorption.
The various NO  control methods are summarized in Table 3.  Table 4 provides
              X
typical tail gas analyses from uncontrolled  plants, plants employing catalytic
reduction, and those using the extended  absorption process.
                                     25

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             TABLE 3.
NOV CONTROL METHODS FOR NITRIC ACID PLANTS1'2
  X
      Process
         Methods
         Impacts
Catalytic reduction
(nonselective)
Catalytic reduction
(selective)
Extended absorption
Wet chemical scrubbing
Chilled absorption
Molecular sieve
adsorption
 Reduce NOX and 02 with CH*,
 H2 or CO to form N2, H20,
 and C02.  Pt or Pd catalyst
 used.

 Reduce NOX with NH3 using a
 Pt catalyst to form N2 and
 H20.

 Uses an additional absorp-
 tion unit.
 Scrubbing tail gases with
 urea, NHs, NaOH, sodium
 carbonate or potassium
 permanganate.

 NOX solubility increased in
 chilled H20.
 Uses synthetic zeolite ad-
 sorbent/catalyst bed.  NO
 recycled by thermal regen-
 eration.
Fuel penalty usually
required.  Operable at
any pressure.  Energy
recovery possible.

Energy recovery not pos-
sible.  Operable at any
pressure.

Increases yield of HN03.
Requires inlet pressure
of 760 KPa.

Operable at any pressure,
but performs better at
high pressure.
Usually cannot meet NSPS
alone when plant operated
at capacity.
High energy and capital
requirements.
sions <50 ppm
NOX emis-
                                     26

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             TABLE 4.  TYPICAL NITRIC ACID PLANT TAIL GAS EMISSION
                       COMPOSITIONS (PERCENT BY VOLUME)
Component
or tail
gas
NO
N02
N2
°2
H20
co2
Plant control method
Uncontrolled3
0.10
0.15 :
96.15
3.00
0.60

Catalytic
reduction
0.01
trace
94.20
trace
3.80
2.00
Extended ,
absorption

0.015
96.00
3.50
0.50

Conventional design has been 98 percent absorption efficiency (this
 composition is typical of the tail gas before catalytic reduction).
 This plant is controlled by increasing the absorption efficiency to 99.8
 percent plus.
3.3.1  Catalytic Reduction1'2
3.3.1.1  Nonselactive—
     As illustrated in Figure 10, the nonselective catalytic reduction unit
is an integral part of the nitric acid plant design when it is used.  Converter
effluent gas is used for preheating the tail gas from the absorption tower.
In the catalytic unit, fuel is burned to generate heat and reduce NO  emissions
                                                                    X
in the tail gas.  Hot exhaust gases from the catalytic unit are directed to
an expander to drive the ammonia converter process air compressor.  To keep
the expander inlet temperature below its design maximum, typically 677°C
(1250°F),% a waste heat boiler is sometimes used directly after the catalytic
unit.  Prior to venting the tail gas to the atmosphere, a waste heat boiler
recovers energy from the expander outlet gas in the form of steam.
     In nonselec£ive reduction, absorber tail  gases are mixed with a fuel  such
as methane, carbon monoxide, or hydrogen and heated to the required ignition
temperature.  Ignition temperatures range from 150°C to 200°C for carbon
monoxide and hydrogen and from 480°C to 510°C for natural gas (methane).  The
absorber tail gas fuel mixture is passed to the catalytic reduction unit
                                     27

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                              28

-------
where the fuel reacts with NOX and oxygen to form C02, water, and nitrogen
over a 0.5 percent platinum or palladium catalyst.  When methane (natural
gas) is used for fuel, the following reactions occur:
CH
20
             C0
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CH- + 4N00 ->• 4NO + CO,
                     4NO
             C0
                                        2H20
                         2H20
     These reduction reactions are highly exothermic.  The temperature rise
resulting from catalytic reduction is 128°C for each percent oxygen burnout
when methane is used as the fuel, and 150°C when hydrogen is employed.  Due
to the catalyst thermal limitation, the final  reduction reaction must be
limited to a temperature of 843°C (1550°F).  It is interesting to note that
the second reaction given above does not decrease total NO  emissions; it
                                                          }\
simply converts N02 to colorless NO.
     Although the catalyst thermal limitation is 843°C, the-maximum tempera-
ture limit for the turbo-expanders is approximately 650°C (1200°F).  Thus,
absorber tail gas with greater than 2.8 percent oxygen will  require cooling
to prevent catalyst deactivation.  Even greater cooling is required if power
recovery is practiced.  In the single-stage units, ceramic spheres are used
as catalyst supports, at hourly gas space velocities up to 30,000 volumes per
hour per volume.  Single-stage units can only be used when the oxygen content
of the absorber tail  gas is less than 2.8 percent.  The effluent gas from
these units must be cooled by heat exchange or quenched to meet the temperature
limitation of the turbine.  Two-stage reduction units often employ honeycomb
ceramic catalysts, with hourly space velocities of approximately 100,000
                                          o
volumes per hour per volume in each stage.    One system uses interstage heat
removal  while another feeds only 70 percent of the fuel  to the first stage
and uses the remaining 30 percent (preheated to only 250°F)  for contact  '
                   9 12 13
interstage cooling. '  '    This second system eliminates the need for coolers
or waste heat boilers.  Historically, experience with single-stage reduction
units has been more satisfactory than that  obtained with  two-stage units.
                                     29

-------
     Usually, 90 to 95 percent of the nitrogen oxides in the tail  gas are
decomposed by nonselective catalytic reduction.  Table 5 summarizes the
typical operating conditions for both selective and nonselective reduction
units.  Fuel requirements for nonselective reduction with natural  gas are
typically 10 to 20 percent over stoichiometric, and some hydrocarbons and
CO are discharged in the treated tail gas.  Less surplus fuel  is required
when hydrogen is used.  The particular process chosen is governed  by a
balance between capital costs and the availability and cost of fuels.  Sig-
nificant economic return, however, can be obtained by recovery of  heat
generated in the reduction unit, depending on the overall plant heat balance.
3.3.1.2  Selective—
     In the selective catalytic reduction process, ammonia is  added to absorber
tail gas and the mixture is usually directed through a honeycomb support
platinum or another type catalyst.  The following reactions occur  and reduce
the nitrogen oxides to nitrogen:
8NH3 + 6N0
4NH  + 6NO
                                       5N
Proper operation of this process requires that the tail  gas stream be maintained
between 210°C and 270°C.
 Above 270 C, ammonia may be oxidized to NO  and
                                           /\
below 210 C, ammonium nitrate may be formed.  This process can operate at any
pressure.  Many systems, however, operate at ambient pressure.  User experience
with this process has been good with catalyst lifetimes of over two years
reported.  The cost of ammonia,' however, may not be competitive with other
fuels even when less is required.  On the other hand, the process does not
require any gas stream cooling, and its lack of pressure sensitivity makes it
applicable as a retrofit control device for existing low pressure nitric acid
plants.
3.3.2  Extended Absorption
     Prior to promulgation of NSPS in 1971, most nitric acid plants were
designed with absorption efficiencies of 98 percent and an emission rate of
15 to 17.5 kg of NO  (as N09) per metric ton of nitric acid produced.  Since
                   /\       £
1975, increasing the design absorption efficiency has become the preferred

                                     30

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control method for NO  emissions from new nitric acid plants.   Thus the
                     X
extended absorption process, in which a second absorption tower is added in
series to the existing or first absorber, is not really an add-on control
device for new plants but an integral component of the design  for new nitric
acid plants.
     The Grande Paroisse version of the extended absorption process is illu-
strated in Figure 11 along with typical operating conditions.   The nitrogen
oxides in the tail gas from the first absorber is contacted with water in  the
second absorption tower to form additional  nitric acid.  The weak acid from
the second absorber is recycled to the first.   Thus,  no liquid effluent is
created by this process.  Process economics usually require inlet gas pressures
at the absorber of at least 730 Kilopascals (kPa) or  107 psig, and cooling of
the tail gas is generally required if the inlet NOV concentration is greater
              8
than 3000 ppm.   The D.M. Weatherly Company's  version of the extended
absorption process uses cooling water refrigeration to decrease the required
volume and number of trays in the second absorption tower.  In this version
of the process, two cooling water systems are  used for cooling the absorbers.
The entire second absorber and approximately one-third of the  trays of the
first tower are cooled with water at approximately 7°C (45°F).  Other trays in
the first absorber are cooled with normal plant site  cooling water, which  is
generated by mechanical refrigeration.  This refrigeration process is a part
of the ammonia vaporization section of the nitric acid plant.
     The extended absorption process cannot control NO  emissions to the same
                                                      X
degree as that obtained with catalytic reduction, and this process frequently
allows NO  emissions greater than NSPS levels  during  startup and shutdown  and
         X
during periods of high ambient temperatures unless the plant is specifically
designed to compensate for these periods.  Figure 12  illustrates the results
of NSPS performance tests conducted on new nitric acid plants  from 1971 to
1978.  Table 6 summarizes the results of compliance tests obtained from 10
new nitric acid plants that have been constructed since 1979.   A review of
Figure 12 and Table 6 indicates that plants controlled by the  extended absorption
process generally had higher NO  emissions. All  design conditions must be
                               X
precisely controlled for the extended absorption process to operate within
NSPS emission limits.  Absorber pressure, temperature, and the oxygen and  NO
                                                                            /\
content of the tail gas must remain within design limits.  Table 7 shows

                                     32

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       1.0
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                  CURRENT EPA NSPS - NITRIC ACID PLANTS
/         D
           NOT OFFICIAL NSPS TESTS
            O    O i
          0       200      400      600      800


                        PLANT REDUCTION RATE, TPD


               LEGEND


       O CATALYTIC REDUCTION

       D EXTENDED ABSORPTION

       A CHILLED ABSORPTION AND

          CAUSTIC SCRUBBING
                             1000    1200
Figure 12.  NSPS test results of NOX emissions  at  nitric  acid plants.11
                                34

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          TABLE  6.   COMPLIANCE TEST  RESULTS FOR NITRIC ACID PLANTS
                 SUBJECT TO THE  NSPS SINCE THE 1979 REVIEW11
Plant
A
B
C
D
E
Fa
G
H
I
J

Control
technique
Chilled absorption &
caustic scrubbing
Catalytic reduction
Extended absorption
Extended absorption
Extended absorption
Extended absorption
Extended absorption
Extended absorption
Extended absorption
Extended absorption
Average
NO emissions,
x Ib/ton
1.84
1.13
1.3
2.75
1.8
4.1
2.55
2.81
2,74
2.13
NSPS = 3.0
Plant was tested upon startup,  then  shut down,  and  has  not  restarted.
                                     35

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TABLE 7.   EXCESS  EMISSIONS  DATA  FROM  EXTENDED ABSORPTION

 NITRIC  ACID  PLANT14 EXPERIENCING  OPERATING  PROBLEMS9'b
Date
7/2/78
7/11/78
7/23/78
8/7/78
8/16/78
8/20/78
8/22/78
8/24/78
8/25/78
8/29/78
Time period
12-1 pm
1-2 pm
2-3 pm
3-4 pm
6-7 pm
7-8 pm
8-9 pm
2-3 pm
3-4 pm
4-5 pm
3-4 pm
4-5 pm
5-6 pm
6-7 pm
7-8 pm
6-7 pm
7-8 pm
8-9 pm
11-12 am
12-1 pm
1-2 pm
2-3 pm
11-12 am
12-1 pm
1-2 pm
2-3 pm
1-2 pm
2-3 pm
3-4 pm
1-2 pm
2-3 pm
3-4 pm
5-6 pm
6-7 pm
7-8 pm
Emissions,
1b NOX per
ton of 100% HN03
3.83
4.52
4.26
3.52
5.89
4.99
4.15
5.71
6.65
3.76
4.27
4.23
3.27.
5.20
3.48
4.25
5.65
2.32
2.81
3.29
3.40
3.07
2.88
3.23
3.24
3.00
5.49
4.17
3.74
4.25
2.89
2.46
3.23
2.63
3.55
Cause
Startup
Startup followed shutdown
due to expander bypass valve
malfunction
Startup
Startup followed shutdown
due to high gauge tempera-
ture trip
Startup followed shutdown
due to NOX compressor trip
Reduced absorption tower
efficiency due to high
ambient temperature
Reduced absorption tower
efficiency due to high
ambient temperature
Startup followed shutdown
due to NO compressor trip
Startup followed shutdown
due to mysterious trip
Startup followed shutdown
due to electrical power
failure
Increased emissions occur during startups due to lag time in establishing
required absorption tower pressure and lowered circulating water temperature.
No external  NOX abatement system is used at this acid plant.

Pounds of NOX are calculated based on 225 ppm(v) equal to 3 Ib/ton at  100
percent production rate.
                               36

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the NO  emissions from one plant controlled by the extended absorption process
      A
during unstable operating conditions and times of high ambient temperatures.
Unstable operating conditions must result in high NO  emissions with this
                                                    A
process because no external control  device is available in these situations
to reduce emissions.   Ambient temperatures of 95° to 100°F create higher NO
                                                                          A
vapor pressures than the second absorber can handle.  For this reason, one
vendor will only guarantee performance within the specified NO  emission
                                                              X
limit 95 percent of the time for plants located in the southern tier of
States.
     Recent trends indicate that the extended absorption process will  remain
the preferred NO  control technology at new nitric acid plants for the next
                /\
several years.  Of the nine extended-absorption process-controlled new nitric
acid plants that came on stream through mid-1978, eight came on stream since
the energy crisis of the mid-19701s.  This control technology choice appears
to have been influenced by the increasing uncertainty of an adequate natural
gas supply (the principal fuel used for catalytic reduction) together with
the anticipated sharp increases in natural gas prices over the next several
years.  The economics of catalytic reduction, however, can be more favorable
than those of extended absorption if the nitric acid plant is to be located
in a fertilizer complex with an available contract for a low-price, long-term
natural gas supply.
3.3.3  Met Chemical Scrubbing
     Wet scrubbing consists of contacting absorber tail gas with alkali
hydroxides or carbonates, ammonia, urea, or potassium permanganate solutions
to absorb NO  in the form of nitrate and/or nitrite salts.  Although these
            X
processes have traditionally been used for retrofit control of existing nitric
acid plants, at least one nitric acid plant subject to NSPS employs a combi-
nation of chilled absorption and caustic scrubbing for NO  control.   Some of
                                                         A
these processes create potentially serious water pollution problems, and if  a
market cannot be found for recovered ammonium nitrate, there is also a solid
waste disposal problem.  Nitrogen oxide control, through use of wet chemical
scrubbing, has generally proved to be adequate.
                                      37

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3.3.3.1  Urea Scrubbing16—
     The MASAR process serves as a representative example of urea scrubbing
and is illustrated in Figure 13.  The process control device consists of a
three-stage absorption column with gas and liquid chillers on the feed gas
and recirculated solvents.  Liquid ammonia or some other form of mechanical
refrigeration is used as the cooling medium.  The chemical reaction mechanisms
proposed for urea scrubbing are as follows:
HN02 + CO(NH2)
    HNCO + HN0
                                           HNCO + 2
                                           C0
                    HNCO + H20 + H+ * NH4 + C0217

Under actual process operating conditions, the last reaction listed above
predominates so that the overall reaction is:
HN02
  CO(NH2)2
                                 HN0
This process has been reported to reduce NO  emissions from 4000 to 1QO ppm
                                           X
and can theoretically be designed for no liquid effluent.   In practice, how-
ever, liquid blowdown of 16 kg/h (35 Ib/h) of urea nitrate in 180 kg/h (396
Ib/h) of water is estimated for a plant with a capacity of 320 Mg of acid/day
(350 tons/day).
     In the MASAR process, absorber tail gas is first cooled in a gas chiller
where condensation occurs with the formation of nitric acid.  Normal  plant
absorber feedwater is chilled in Section C of the MASAR absorber and is then
fed to Section A, where it flows countercurrent to the incoming chilled tail
gas in the packed bed.  After additional N0v is scrubbed from the tail  gas,
                                           X
the scrubbing water is recirculated through a chiller to remove reaction heat;
this weak acid stream is used as feed to the nitric acid plant absorber.  In
Section B of the MASAR absorber, the tail  gas is scrubbed  with the urea-
containing solution forming nitric acid and nitrous acid that reacts to form
CO(NH2)> N2 and FLO.  Recirculation of the scrubbing solution causes the con-
centration of nitric acid and ammonium nitrato to rise.   Therefore,  a bleed
                                      38

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39

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stream is required to keep the system in balance.  Makeup urea/water solution
is fed to the scrubbing system at a rate sufficient to maintain a specified
minimum urea residual content.  To maintain temperature control in Section B,
the recirculated scrubbing solution is pumped through a chiller to remove the
heat of reaction.  Prior to leaving the MASAR unit, the tail  gas is again
scrubbed with plant absorber feed water in Section C.
                          1 ft
3.3.3.2  Ammonia Scrubbing  --
     Goodpasture, Inc., developed an ammonia scrubbing process in 1973 that is
suitable to retrofit existing plants for reduction of an inlet concentration
of 10,000 ppm NO  to within NSPS emission, limitations.  A flow diagram for
                A
the Goodpasture process is shown in Figure 14.  As shown in the figure, the
entire process is conducted in a single packed contact absorption tower with
three sections operated in a concurrent flow.  In the Goodpasture process,
there are three distinct sections of the absorption tower:
     1.   A gas absorption and reaction section operating on  the acidic side.
  ,   2.   A second gas absorption and "reaction section operating on the
          ammoniacal side.
     3.   A final mist collection and ammonia recovery section.
Feed streams to this process are ammonia and water.  Ammonium nitrate is pro-
duced as a byproduct of this process.  Successful operation of this'process
requires that ammonium nitrite formation be kept to a minimum, and any ammonium
nitrite that does form must be oxidized to ammonium nitrate.
     As shown in Figure 14, tail gas enters the first or acidic section of the
tower where NO  in the gas stream is converted to nitric acid.  Ammonia is
              A
added to the process in the second section in sufficient amounts to maintain
the pH at a level of 8.0 to 8.3.  In this section of the tower, ammonia reacts
with NO  in the gas stream to form ammonium nitrate and ammonium nitrite; the
       A
proportion of each is dependent on the oxidation state of the nitrogen oxides.
Product solution from the second section is fed to the first  where ammonium
nitrite is oxidized to ammonium nitrate by the acidic conditions, and ammonium
nitrate is formed directly from the reaction of free ammonia  with nitric acid.
The resulting solution is split into two streams.  One stream is withdrawn from
the process as product solution, while the other is fed to  the second or
ammoniacal section of the tower.  Feed streams to the third and final  section

                                      40

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       TAIL
       GAS IN
   ACIDIC
   SECTION
 PHRC
 AMMONIACAL
 SECTION
       TREATED
       TAIL- GAS
       OUT
       t
MIST COLLECTION
   PRODUCT
  AMMONIUM
NITRATE SOL'N
       STEAM
       CONDENSATE
     Figure  14.  Process flow diagram for the Goodpasture  process
                                                                   1 8
                                    41

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 of the tower consist of process  water or steam  condensate  in  sufficient  quan-
 tities to maintain the  product ammonium nitrate solution in the  30  to  50 per-
 cent concentration range,  and  a  small  amount  of solution from the acidic
 section to control the  pH  to approximately  7.0.   In  this section of the
 process, mists are eliminated, and  any free ammonia  is  stripped  from the
 solution.  Product solution withdrawn from  the  first section  of  the process
 contains 35 to 40  percent  ammonium  nitrate  and  0.05  percent ammonium nitrite.
 The ammonium nitrite can be oxidized  by heating  the  solution  to  240°F or by
 simply holding it  in a  day-tank  for 24 hours  without heating.
      Existing ammonia scrubbing  systems have  given reliable operation and
 have met the emissions  requirements for which they were designed.   An advantage
 of this process is that the pressure  losses are  only 6.8 to 13.0 kPa (1-2 psi),
 which allows the process to be easily  retrofitted for control of existing
 low-pressure plants.  Special precautions must be taken, however, to prevent
 deposition  of ammonium  nitrate on the  turbine blades.  One potential dis-
 advantage of the process is that the requirement for 85 percent ammonium
 nitrate  solutions  by  modern fertilizer"piants can necessitate additional
 evaporators  to concentrate the 35 to 55  percent ammonium nitrate solution
 recovered as  a byproduct from the Goodpasture process.
 3.3.3.3   Caustic Scrubbing15' 19~
      Strong  bases  such as sodium hydroxide and sodium carbonate have been used
 for scrubbing NOX  in  the tail gas from  nitric acid plants.   Typical  reactions
 for caustic  scrubbing are:
2NaOH + 3N0
NaN0
                                                NO
                         2NaOH + NO + N02 -»• 2NaN02 + HLO

One serious problem with this process is that disposal  of the spent scrubbing
solution can create a serious water pollution problem.   At least one nitric
acid plant subject to NSPS, however, has successfully employed a combination
of caustic scrubbing and chilled absorption for NO  control.
                                                  /\
                                     42

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                                         19
3.3.3=4  Potassium Permanganate Scrubbing  —
     Several  Japanese plants employ solutions  of potassium permanganate  for
scrubbing NO  emissions,  but no U.S.  plants are known  to  use the  process.   In
this process, permanganate is reduced to manganate that must be electrolytically
oxidized.  The cost of electrolysis along with permanganate makeup costs are
believed to make this process uneconomical in  the United  States.
                         20
3.3.4  Chilled Absorption u
     The chilled absorption process exploits the increased solubility of NOX
in cold water.  This method has been primarily used as a  retrofit for existing
plants, and as a sole control device, it is not capable of meeting NSPS  emis-
sion limits.  Both water and brine have been used in a closed loop system to
provide local cooling to the liquid on the trays of the absorption tower.
One representative chilled absorption process  is the CDL/VITOK process,  which
is illustrated in Figure 15.  Nitrogen oxide in the tail  gas is both chemically
oxidized and physically absorbed as it is contacted with a nitric acid solution
upon entering the absorber.  In the upper portion of the absorber, cooled water
is employed to improve absorption.  Nitric acid solution from the absorber is
split off to a bleacher where further oxidation occurs and air removes entrained
gases.  Bleached nitric acid solution can either be stored or recycled to the
absorber after the addition of makeup water.  A closed loop system is used to
chill both recirculated acid and cooling water by ammonia evaporation.  Vari-
ations  in the CDL/VITOK process include addition of an auxiliary bleacher
operating in parallel with  the primary unit and use of a secondary absorber
with its own bleacher.
                                 21  22
3.3.5   Molecular Sieve Adsorption  '
     Although the molecular sieve  process  has been somewhat successful  in
controlling  NO  emissions  from existing  plants, there  have been no new  nitric
acid plants  built that are subject to NSPS which employ this form of N0x con-
trol.1   Principal objections to the  process are high capital and energy costs,
the problems of coupling  a cyclic  system to a continuous acid  plant oper-
ation,  and  bed  fouling.   In addition, molecular sieves are not considered as
state-of-the-art  technology for NO  control in  nitric  acid plants.   '    A
                                   /\
flow diagram of the  Purasiv control  system that was developed  by Union
                                       43

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     44

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Carbide is shown in Figure 16.   The pressure drop through the sieve bed is
rather high and averages 34 kPa (5 psi).   The average concentration of NOX  in
the treated tail gas discharged to the atmosphere, however,  is only 50 ppm.
     The fundamental principle behind molecular sieve control is selective
adsorption of NO  followed by recycle of the NO  back to the nitric acid
                A                              A
plant absorption tower.  As illustrated in Figure 16, the first step of the
process is to chill the absorber tail gas to between 7° and  10°C; the exact
temperature required is governed by the NO  concentration in the tail gas
                                          A
stream.  Next, the chilled gas is passed through a mist eliminator to remove
entrained water and acid mist.   Weak acid collected in the mist eliminator  is
either recycled to the absorption tower or stored.  Partially dried tail gas
then passes to the sieve bed where several operations proceed simultaneously:
     1.   Dessicant contained in the bed removes the remaining moisture
          from the gas stream.
     2.   NO in the tail gas is converted catalytically to NO,,.
     3.   NOp is selectively adsorbed.--
Regeneration is accomplished by thermal-swinging  (cycling) the adsorbent/
catalyst bed after it is nearly saturated with N02.  Regeneration gas is
obtained by heating a portion of the treated tail gas in an  oil- or gas-fired
heater.  This gas is then used to desorb N02 from the bed for recycle back
to the nitric acid plant absorption tower.  Both adsorption  and regeneration
of the bed require approximately four hours.
                          23
3.3.6  Emerging Technology
     The new Bolme nitrogen oxides recovery process recovers NOX removed from
tail gas and recycles it as feed to the plant absorption tower.  When installed
in a new medium-pressure plant, as part of an integrated nitric acid-NOx
recovery system, it can reduce total capital cost and yield a modest increase
in operating profit.  The process is illustrated  in Figure  17 and design
specifications  are  listed in Table 8.  In essence, the process employs a 25
to 30 weight percent nitric acid solution for scrubbing NOX  in absorber tail
gas, and then the  recovered NO  is steam  stripped from the  scrubbing solution
                              A
and  recycled.   This process can be economically designed for NO  emissions of
                                                               /\
only 70 to 85 ppm  when  operated at capacity during the hottest week  of  the
                                      45

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                     .	+. 1000  PPM  NOX

                r-""  -^  (TREAT TO DESTROY)
                             2640  PPM
  NOX
           tJ
        2A
                             PRODUCT   MU-»
Ji_


sc



-««.



c
1

> ,
i
ss

i



i

IHE
p ;
1 1
t

                                                  PS
 F * FEED



 C * CONDENSER



 B = BLEACHING SECTION



 A = ABSORBER



SC = SCRUBBING SECTION



 W - MASHING SECTION



06 - CLEAR GAS



FW * FEED WATER



AM * ACID WASH
  PS * PREGNANT SCRUBBING SOLUTION



  HE * HEAT EXCHANGER



  ST - STRIPPING TOWER



  SS » STRIPPED SOLUTION


 T-C ' TRIM COOLER



RNOX = RECOVERED NITRIC OXIDER



  BL * BLEED



  RA * RECOVERED ACID
    Figure 17.   The  Bolme NO  recovery  system.23
                                   A
                               47

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TABLE 8.  DESIGN SPECIFICATIONS FOR THE BOLME NOX RECOVERY PROCESS APPLIED

    TO A NEW 220-METRIC-TON-PER-DAY MEDIUM-PRESSURE NITRIC ACID PLANT23
             Combined scrubbing-stripping tower:

               Diameter, m (in.)	        2        (80)
               Internal cooling 	     none
               Trays (sieve type)
                 Scrubbing, number  	       15
                 Washing, number  	      3-4
                 Stripping section,  number  ...        3

             Feed/Product heat exchanger
               (Spiral  type,  i.e., coiled sheet)
               area, m2 (ft2)	      440     (4,750)

             Trim Cooler (Spiral type, i.e.,
               coiled sheet)  area, m2 (ft2) ...       65       (700)

             Liquid ring compressors (Nash or
               Siemens-Hinsch) Vacuum-to-
               atmospheric
               Atmospheric-to-recycl-e pressure

             Pump, liter/h (gal/min)  	  115,000       (500)

             Condenser

             Controls

             Operating  costs  and benefits

             Utilities:
               Steam @  5 lb/in.2 gauge (130 kPa-
                 gauge), kg/h (Ib/h  	    1,745     (3,850)
               Power, kW	      125
               Cooling  water, liter/min  (gal/min)    2,500       (660)
             Benefits:
               HNOa  from RN02  (2500 -> 100 parts/
                 million),  kg/day (lb/day)   .  .  .
4,670    (10,295)
                                   48

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year.  As indicated in Figure 17, one major advantage of the process is that
the nitric acid plant absorber is 40 percent smaller than one required to
reduce the NO  tail gas concentration to 1000 ppm.  Another significant oper-
             A
ating advantage of the process is that it tends to compensate for upsets.  For
example, a 2640 ppm jump in the NOV entering the recovery process will produce
                                  A
only a 283 ppm jump in the NO  in the exhaust,
                             X
     The Bolme process is tased on the same three"reactions as~the nitric acid
process itself:
     1.
     2,
     3,
2ND + 0
           2NO,
             HN0  + HN0
3HN0  + HN0
               H20
  3
2NO
              •/O   1 I ll Wo

The scrubbing solution employed in the process stabilizes nitrous acid and
removes it as fast as it is formed.  This is accomplished by using a 25 to 30
weight percent nitric acid solution that can reverse the last reaction,
but allows the second reaction to proceed in the indicated direction.   The
solubility of nitrous acid is maximum in this concentration of nitric  acid.
The recovery process chemistry is complimentary to that of the basic nitric
acid process.  At low NO  partial pressures, the Bolme process works well,
                        A
while at high NO  partial pressures, the basic nitric-acid process works
                A
efficiently.
     As illustrated in Figure 17, the integrated NO  control method begins
                                                   A
with the normal nitric acid process.  The feed (F) passes through a condenser
(C) and enters the absorption tower.  Secondary air passes through a bleaching
section (B) and joins the feed.  These combined streams then enter the plant
absorber (A); tail gas from the absorber contains 2600 ppm NO .  Tail  gas is
                                                             A
then directed to the scrubbing section (Sc) where the NO  content is reduced
                                                        A
to approximately 150 ppm (70% N02).  Exit gas from the scrubber enters the
washing section (W) where it is contacted with feed water (FW) to convert N02
to HN03 and NO.  Clean gas (CG) from the washing section is sent to the power
recovery and the acid wash (AW) is fed to the absorber.  Pregnant scrubbing
solution (PS) is heated to approximately 70°C in a feed-product heat exchanger
(HE) before it is stripped with steam in the stripping tower (ST) to produce
the stripped solution (SS).  Stripped solution is first cooled in the same
                                      49

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heat exchanger (HE) and then further cooled in the trim cooler (T-C)  prior to
recycle.  Recovered nitrogen oxides (RNOV) are cooled in a condenser  and
                                        X
compressed for recycle; bleed (Bl) is also compressed and the combined streams
are recycled to the absorber inlet.  Recovered acid (RA) joins the acid wash
as feed to the absorber.
                                     50

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                                   SECTION 4
                      STARTUP, SHUTDOWN,  AND MALFUNCTIONS

     Prior to the inspection of a nitric  acid plant,  the field inspector
should become familiar with the plant's startup and shutdown procedures  and
also with possible plant malfunctions.
     All ammonia oxidation nitric acid  plants use platinum alloy catalysts to
promote the oxidation reaction.  The efficient life of a catalyst varies in
each plant as a result of the plant's design and operation practices.   In
general, however, the catalyst at pressure process nitric acid plants  is
changed once a month.  This catalyst renewal requires a complete plant shut-
down and startup.  Additional unplanned shutdowns and startups are due to
abnormal process conditions such as abnormally high temperatures and/or
pressures that jeopardize the mechanical  or process equipment.
     In addition to abnormal process shutdowns, any of the following service
upsets or failures will result in a plant shutdown:
          1.   Mechanical and/or process equipment,
          2.   Ammonia supply,
          3.   Lack of usage or storage for nitric acid,
          4.   Waste heat boiler feed water,
          5.   Absorber feed water,
          6.   Cooling water,
          7.   Instrument air, and
          8.   Electric power.
The average modern nitric acid plant will have 20 to 30 set points that, when
exceeded, will trigger an automatic plant shutdown.  Shutdowns due to service
failures and abnormal process  conditions are a function of the owner's mode
of performance.   Poor maintenance and operation will result in frequent shut-
downs.   Good maintenance and operating habits, however, should minimize these
shutdowns to approximately  one per month.
                                       51

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 4.1  STARTUP
      Before the ammonia  oxidation  reaction  is  started  in  a  nitric acid plant,
 not only must all  of the process equipment  be  in operating  condition, but all
 of the numerous services must  be available.  With  these prestartup conditions
 assured, the next  procedures are:
      1.    The air  compressor has been  run at a low rate until it is at its
           operating  temperature and  pressure.
      2.    The ammonia vaporizing and supervising system is  at operating
           temperature and pressure.
      3.   -All  downstream equipment such as  heat exchangers, waste heat
           boilers, and cooler-condenser are warmed up with  auxiliary steam.
      4.
      5.
      6.
The cooling water is circulating in the absorber.
The absorber feed water rate has been adjusted for startup.
The platinum catalyst gauze has been preheated and ready for the
light-off.
Under these conditions, the air flow is diverted to the ammonia-air mixer and
the ammonia vapor is added.  The mixture passes over the catalyst in the con-
verter, which is at ignition temperature, and the ammonia oxidation reaction
starts.  As the hot reaction gases pass through the preheated exchanger train,
the warmup stream is shut off and a water spray wash is turned on to wash out
ammonium nitrate and nitrite salts that form during this period of the startup
(these salts are formed by unreacted ammonia and nitrogen oxides fumes during
startup and are highly explosive).  The bleach air flow is started and all
air and ammonia flows are increased and adjusted until  the desired operating
conditions and rates are reached.  The reaction gases flow to the absorber
where the oxi'dation of nitrogen oxide continues and absorption produces the
product acid.
     The tail gas leaving the absorber reaches its equilibrium when the process
upstream has leveled out at the selected operating rate temperature, pressure,
etc.  Only when this is achieved and the reheated tail  gas is driving the
power recovery expander can a catalytic reduction unit  be put on stream.   If
the reduction unit were placed on stream before the tail  gas  had reached  its
reheated temperature,  reaction ignition would not take  place  and the unit
                                      52

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would not operate.  The tail gas composition must be stabilized with the
oxygen concentration design limits when the unit is ignited and put in oper-
ation because wide oxygen fluctuations would prevent proper operation.  Con-
centrations above the design concentrations will produce temperatures above
the thermal limitation of the catalyst and result in a safety shutdown.
During this period before the catalytic reduction unit can be put on stream,
very careful startup operation is necessary to keep the plant emissions to a
minimum.
     Should the plant be designed with sufficient absorption efficiency and
no control device, the startup must be well controlled to keep the absorption
process stabilized.  With the absorption process under control, no difficulty
should be experienced in meeting the standard during the startup period.
     Desirable conditions for adsorption systems (molecular sieves) are con-
stant bed temperatures, feed rates, and gas composition.  If a nitric acid
plant is equipped with an adsorption system, it must be preheated and put on
stream when the tail gas composition and temperature have stabilized.  This
means that  the unit will be the last equipment  put  into operation.  As with a
catalytic  reduction system, before the adsorption unit is in operation, very
careful startup operational procedures are  required to keep the plant's emis-
sions to a  minimum.

4.2   SHUTDOWN
      The  first step  in the  shutdown of a nitric acid  plant  is  to  reduce the
production rate,  usually to approximately  one-half  of  the design  rate.  This
is done by reducing  the  reaction  air  flow  to  the ammonia-air mixer.   The  flow
ratio controller  maintains  the  correct amount of ammonia  flow  as  the  air  flow
 is reduced.  Next,  the ratio  of ammonia  to ammonia-air mixture is reduced,
which lowers  the  reaction  temperature (catalyst gauze); when  the  catalyst has
cooled  to approximately  1000°F, the  ammonia flow is shut  off.   After  the  ammonia
 flow is shut off, the catalytic unit should be  shut down  because  the  oxygen
 concentration in  the tail  gas will  increase and the catalytic  unit temperature
will rise to the  thermal  limitation  set  point and  it will  cause an automatic
 shutdown.  At this point,  the air flow is  further  reduced;  care must be taken
 to maintain the pressure of the absorption column, or excessive emissions
                                       53

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 will result.  The air flow is continued until  all  nitrogen oxides are purged
 from the tail gas heater, waste heat boiler, and cooler-condensers.   All  drains
 from these exchangers are opened to purge condensed water and weak acid.   The
 bleach air is now shut off and the absorption  water to the absorber is  reduced.
 The air to the ammonia-air mixer may now be reduced to a  minimum permitting
 the compression train to turn slowly and cool.   The compression  train must be
 cooled down carefully to avoid damage.   As the plant is cooled down,  all
 services such as boiler feed  water,  absorber water,  and cooling  water should
 be shut off.  During  this purge and  cooling of the  plant,  the absorber  pressure
 and cooling must be maintained until  the maximum amount of unabsorbed nitrogen
 oxides are absorbed,  or excessive emissions will result.
      A nitric acid plant designed with  sufficient absorption  capacity without
 an emission control system will  have  the same  shutdown procedure  as described
 in the previous  paragraph (excluding  the catalytic  unit shutdown).  The same
 care must be exercised  to maintain absorption  pressure and  cooling or excessive
 emissions will  result.
      If a nitric  acid plant is  equipped  with an  adsorption  system, it must be
 purged back into  the absorber  (all beds)  to remove all  nitrogen oxides before
 the ammonia  feed  to the  converter  is  shut  off.   This cleans the unit  of
 nitrogen oxides.  The nitrogen  oxides are  absorbed before the  plant temperatures
 change and while  the purge  gas  is  normal.   If the adsorption  unit was operated
 to  the end,  the oxides would have  to  remain in the cold adsorption beds or be
 purged to the atmosphere.   It would not  be desirable to keep  the oxides absorbed
 in  a cold adsorption bed.  As in all  nitric acid plants, during shutdown the
 pressure  and cooling must be maintained on the absorber tower or excessive
 emissions will result.

 4.3  MALFUNCTIONS
     Any nitric acid plant designed with sufficient absorption capacity or
 equipped with emission control devices will have difficulty controlling their
emissions if they experience any of the following upsets or malfunctions:
     1.
Insufficient process air (converter and bleach air) will  result in
an excess of unoxidized nitrogen oxide that the absorber  and
catalytic unit cannot eliminate.
                                      54

-------
2.   Insufficient cooling of the cooler-condensers  and  absorber  will
     hinder the absorption of nitrogen dioxide and  tetroxide.

3.   Operation of the cooler-condenser and absorber below the  design
     pressure will lower the absorption efficiency  and  overload  the
     abatement system with nitrogen oxides.

4.   If the plant is operated above design production rate and/or  acid
     concentration, the cooler-condensers and absorber  will  not  perform
     at their designed efficiency.

5.   The mechanical failure of pumps, control valves, instruments, etc.,
     will create unstable operations such as insufficient cooling, poor
     reactant flow control, etc., which will hinder the proper absorption
     and catalytic unit operations.

6.   Process equipment malfunctions such as leaking exchangers could
     easily allow bypassing of nitrogen oxides past the catalytic  unit
     to the atmosphere.  Plugged trays in the absorber  would reduce
     absorption efficiency.

7.   The loss of any utility such as waste heat boiler  feed water,
     instrument air, electricity, and process water would trigger
     an emergency shutdown that would vent excessive nitrogen oxides
     to the atmosphere.
                                  55

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                                    SECTION 5

                           PROCESS CONTROL SYSTEM AND
                       EMISSION MONITORING INSTRUMENTATION
      Monitoring instrumentation plays three very important roles  in the
 operation of a nitric acid plant:

      1.   Informing the plant operators and inspectors  of the  various  flows,
           temperatures, pressures,  and concentrations  necessary to  define
           plant performance and emission control  performance.

      2.   Performing process control  functions  such  as  automatic  flow  control,
           automatic temperature control, and other control  functions that may
           be performed along with the monitoring of  these functions.

      3.   Helping to protect the process from damaging  and  hazardous operating
           conditions through the use  of alarms,  which notify the  operator
           when control  limits are reached,  and  the use  of trip-out  and  inter-
           lock systems, which shut  down parts or all of the plant when  certain
           preset control  limits are reached.

 Therefore,  based on the above instrumentation functions,  all nitric acid

^plant inspectors must be thoroughly familiar with  all types of  plants,  control

 systems,  and emission monitoring instrumentation  that can be encountered in

 the industry.   The following sections  will  define  the general concepts  of

 performing  the above monitoring functions.   After  understanding the general

 concepts,  the  plant inspector must  become familiar with the particular  details

 of  each plant's  monitoring  system.  With a  thorough understanding of the

 monitoring  information,  a plant inspector will be  able  to determine such

 important parameters  as  plant process  and production rates  during the inspec-
 tion.
5.1  PROCESS MONITORING INSTRUMENTATION

     Although the nitric acid manufacturing process has many variations, the

basic ammonia-oxidation process can be considered a baseline for monitoring

nitric acid manufacturing processes.  Figure 18 is an instrumentation flow
diagram of the AOP process.
                                     56

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     The plant production rate is controlled by the air and ammonia feed
rate.  The air rate to the air-ammonia mixer is manually set and controlled
by a flow indicating controller.  This flow rate may also be recorded by a
flow recorder.  The ammonia flow to the mixer is regulated by a ratio flow
control system governed by the air flow.  The control system records air and
ammonia flow rates; the ammonia flow is adjusted to the desired set point
ratio which is selected on the ratio flow control to maintain a constant
concentration between 9.5 and 10.5 volume percent ammonia in the process
stream.  The balance of the air needed for the process (approximately 20
percent) is introduced into the bottom.of the absorber by a flow indicating
controller.  This bleach air flow rate may also be recorded by using a flow
recorder.  The sum of these two air streams is the total  air flow introduced
into the process.  The introduction of water (condensate grade) to the absorber
is controlled by a flow indicating controller and is adjusted to produce the
amount (at a definite concentration) of acid to be generated by the air and
ammonia feed rates.
     The rate of nitric acid product reaving the bottom of the absorber (or
bleach column if the plant has one separate from the absorber) is measured by
a flow recorder.  The nitric acid concentration is determined by taking the
specific gravity of a sample at regular intervals.  Some plants may have a
recording density instrument to determine the acid concentration.  In any
event, a reliable production rate measurement method must be provided and be
sufficiently accurate to comply with the NSPS standard.   The absorber gas
flow inlet and outlet are equipped with temperature and pressure indicators
that aid the operators in maintaining the optimum conditions for absorption
efficiency.
     The exit gas flow from the absorber (tail  gas) has numerous temperature
and pressure indicators before and after the equipment that it must pass
through before being exhausted to the atmosphere.  Some of these temperature
indicators have high temperature alarms to alert the operators when there is
danger to certain equipment with temperature limitations,  such as the expander
(temperature limit is usually 1250°F) and catalyst in the catalytic unit (if
the plant has one).
     The catalytic unit may be controlled by an oxygen analyzer which, through
a ratio controller, adjusts the fuel  feed rate to the unit for efficient auto-
matic operation.
                                      58

-------
     The tail gas stream is analyzed for nitrogen oxides before being exhausted
to the atmosphere.  This instrument is required by the NSPS and must be an
indicating-recording analyzer (reading in ppm nitrogen dioxide).   It must be
in continuous operation and maintained in optimum operating condition at all
times.
     The instrumentation shown in Figure 18 is only the minimum required for
the process control.  The following auxiliaries have numerous  instruments and
controls for their proper operation and plant protection,  and  the inspector
should become familiar with instrumentation for these processes.
     1.   Compression train (startup turbine, compressor,  and  expander),
          Ammonia vapor supply system,
          Waste heat boiler feed water supply system,
          Cooling water system,
2.
3.
4.
5.
          Absorber water supply and treatment (condensate quality for
          absorption),
     6.   Product nitric acid storage,  and
     7.   Electric supply system.
These various systems are interlocked with the process  controls,  so  it is
important that their possible effects on plant production and emission control
be understood.

5.2  EMISSION CONTROL INSTRUMENTATION
     It should be emphasized that  there are many possible instrumentation
concepts for the control techniques discussed in Section 3.3.   The following
section discusses a general  type of instrumentation scheme for each  control
technique.  The inspector should become familiar with the details of a given
emission control instrumentation scheme prior to the inspection.
5.2.1  Catalytic Reduction
     The control instrumentation used on catalytic reduction  units is as varied
as the number of suppliers.   The simplified general  flow diagram  in  Figure  19
illustrates the instrumentation scheme recommended by one supplier but is not
the only system in use.
                                     59

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     The fuel must be clean (free of sulfur compounds, etc.) to protect the
catalyst and should be well mixed with the tail  gas before passing over the
catalyst.  The flow rate of fuel  gas is controlled by the oxygen concentration
in the tail gas.  The oxygen concentration is determined by a continuous ana-
lyzer that measures and controls  the fuel  flow rate.   The fuel  concentration
in the tail gas is analyzed by an analyzer-controller that maintains the flow
rate as required by the oxygen analyzer and controller.   The ratio of fuel  to
oxygen is controlled by a ratio flow controller in the system.   This ratio  is
selected to maintain optimum operation and protect the catalytic unit from
excess fuel that would decompose  and poison the catalyst (carbon).  In ad-
dition, a temperature recording controller with a high alarm is used to warn
the operator of abnormally high temperatures (usually about 1500°F) that
would damage the catalyst.  As an additional safety precaution, this control
will also shut off the fuel supply if there is a lapse in time.
5.2.2  Absorption
     Emission control by absorption is-somewhat misleading as no emission
control equipment is necessary if the plant is designed and built with suf-
ficient absorption capacity to ensure that the emissions will be below the
NSPS standard.  A plant so designed will need no additional instrumentation
because the normal process instrumentation will  be sufficient.
5.2.3  Molecular Sieves
     The operation of molecular sieve adsorption systems tends to be simple.
Most operate on automatic valve sequencing, with time mechanisms providing
primary control.  Performance evaluation is based on flow, temperature, pres-
sure, and composition measurements.  The adsorption instrumentation diagram
shown in Figure' 20 schematically illustrates desirable instrumentation.  The
analyzer-recorders for the inlet and outlet gas flows determine the nitrogen
oxides concentrations as nitrogen dioxide.  From these two analyzers, the
unit's efficiency can be monitored.  The exit analyzer does not replace the
continuous stack monitor as required by the NSPS.  The various sample con-
nections are not only designed for gas samples but for absorbent samples as
well.  These absorbent samples are useful in measuring the unit's performance
and in projecting when the absorbent will have to be changed.  These adsorbent
analyses also help to identify other adsorbates and adsorbent poisons.
                                      61

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5.3  EMISSION MONITORING INSTRUMENTATION
     Several different types of continuous emission monitoring techniques may
be used to determine the NO  concentrations in the tail  gas prior to release.
                           X
Some of these methodologies are summarized below.   Each  system has both ad-
vantages and disadvantages and the monitor selector must take this into con-
sideration along with the stack conditions expected to be encountered.
5.3.1  Ultraviolet Absorption-
     The main type of ultraviolet absorption monitor is  the nondispersive
ultraviolet analyzer shown in Figure 21.  This analyzer  uses the concept of
a split-beam photometer.  It monitors the concentration  of a pollutant  by
measuring the difference in the amount of radiation absorbed at two different
wavelengths (ultraviolet, visible, or near-infrared).   Radiation from the
source, usually a gas discharge lamp, is partially absorbed as it passes
through a sample of gas.  As radiation leaves the  sample, it is divided into
two beams by a semitransparent mirror.  Each beam  then passes through an optical
filter that removes all wavelengths except the one to  be measured.  The filtered
beam then strikes a phototube.  The beam splitter  is set up to reflect  and
transmit so that the intensities of the radiation  striking each phototube will
be nearly equal during normal operation of the analyzer*
     The beam reaching one phototube is in a wavelength  that is absorbed
strongly by the pollutant being measured; thus, this beam actually measures
the concentration.  The beam directed to the second phototube is in a wave-
length that is absorbed weakly or not at all by the pollutant and is used as
a reference.  If the concentration of the absorbing pollutant changes,  the
intensity of radiation reaching the first phototube varies in accordance with
the concentration of pollutant.  The radiation to  the  second phototube  varies
very little, or not at all.
     In each phototube, the current flow is proportional to the intensity of
radiation striking the phototube.  This current is fed to an amplifier  that
outputs a dc voltage that varies logarithmically with  the current, and, hence,
with the intensity of the radiation.  Voltage output from the reference beam
amplifier is subtracted from that of the measuring beam amplifier.  This dif-
ference in voltage ouput varies linearly with the  concentration of the  pollu-
tant being measured.  Therefore, the gaseous pollutant concentration may be
read directly or indirectly through the difference in  output voltage.
                                      63

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5.3.2  Infrared Absorption
     Two main types of infrared sensors are commonly used—nondispersive and
dispersive.  The term "nondispersive" refers to the lack of a light-dispersing
element such as a prism or grating that selects a particular analytical  wave-
length of light.  The more traditional  Luft-type nondispersive infrared  (NDIR)
analyzer has been used to make process  and environmental  measurements of nitric
oxide for over 20 years.  A schematic of this type of analyzer is shown  in
Figure 22.
     In the NDIR analyzer, two identical infrared-radiation emitters serve as
matched sources of broad-brand infrared energy.  Radiation from these sources
is modulated by a motor-driven chopper disk, and passed through filters  and
measuring cells into an energy receiver.  The reference cell is filled with
a gas such as nitrogen that does not absorb infrared energy.  Another cell
contains the gas being analyzed.  The amount of infrared energy passing  through
the analysis cell that will be absorbed by the gas depends on the concentration
and wavelength band of the gas.
     The energy receiver consists of two chambers separated by a membrane.
Both chambers are filled with a mixture of argon and the gas to be measured.
As the gas absorbs infrared energy, it heats up and pressure increases.   If
the two chambers are exposed to equal amounts of energy, the membrane will
remain in a neutral position and there will be no output from the instrument.
Because the gas in the analysis cell absorbs more energy, pressure on that
side of the chamber increases and the membrane deflects.  This deflection is
detected as a change in electrical capacitance between the membrane and  a
fixed electrode and therefore, as a change in ac voltage at a resistor.   This
ac voltage change is displayed as dc current using a measuring amplifier on
an indicating instrument.
     If the gas to be tested contains components with absorption bands that
slightly overlap those of the pollutant being measured, identical filter cells
are filled with the interfering components to screen them out.  This "positive
filtering" makes it easier to measure the pollutant.
     The Luft-type NDIR analyzer generally uses an extractive sampling system
to transport the sample of stack gas to the analyzer.  Particulate matter and
water vapor that interfere with the species measurement are removed.  Generally,
Luft-NDIR analyzers are used to monitor S02, N02, NO, CO, and CO,,.
                                      65

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     A schematic of another nondispersive analyzer is  shown  in Figure 23.   In
contrast to the Luft-type analyzer,  which looks at a broad spectral  region  and
must be sensitized for each particular gas using a detector  cell,  this NDIR
spectrometer can be set at any wavelength within its range.   In addition, the
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When many absorbing gases are present, however, it may be difficult  to locate
a wavelength in a spectral region where other gases do not absorb.
     The analyzer shown in Figure 23 uses a narrow-band pass filter  that scans
the spectral region between 2.5 and 14 microns.  Because the analyzer has a
variable path length from 3/4 to 20 meters, it has a large sensitivity range.
These and similar analyzers can measure many gases simultaneously;  however,
other gases, water vapor, or particulates may cause absorption problems in
the spectral region of the pollutant.
     Another type of NDIR analyzer is the gas cell correlation spectrometer
shown in Figure 24.  EPA researchers are investigating this, type of  analyzer
as an in-situ analyzer for various pollutants.  The analyzer uses a  broad band
IR source and detector, one or two cells filled with varying concentrations
of the gas to be measured to provide the wavelength selection.  This technique
has shown potential for rejecting interference.  Thus, it can be used to
improve low level sensitivities, or to simplify or eliminate requirements for
sampling systems.  In addition, switching selection cells allows several pol-
lutants to be monitored by the same unit.  Figure 25 shows a single-beam,
dual wavelength NDIR analyzer.  In this analyzer, a single IR radiation beam
is passed through the sample gas and filtered into two wavelengths by a
chopper.  The wavelengths are chosen so that one wavelength has no absorption,
while the other has maximum absorption.  The ratio of their absorptions is
sensed by a conventional  thermal electric  IR detector.

5.4  CHEMILUMINESCENCE
     Chemiluminescence is a chemical and optical monitoring technique.  In
this technique, a gas molecule reacts with a reagent to form an excited molecule
that spontaneously decays, producing photoemissions.  Sensitivity, rapid
response time,  and instrument stability make the chemiluminescence method
                                     67

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      PATHLENGTH CAN BE VARIED WITH AN OUTSIDE ADJUSTING
      KNOB  FROM 3/4 METER TO MORE THAN 20 -METERS
PATHLENGTH
ADJUSTMENT
                                                   FILTER
                                                   WHEEL
                      SAMPLE  CELL
                                           OUT  IN
          FIELD MIRROR  // i
               HIGH CONCENTRATION  CELL  LOCATION-^      SOURCE
                                                                        ELECTRONIC
                                                                       "BOARD
                 Figure 23.   Variable wavelength  NDIR analyzer.
CORRELATION
   CELL
                                              BAND
                                    SAMPLE    PASS
                                     CELL    FILTER
               SOURCEQ=
                                                    DETECTOR
                     ATTENUATOR
                                                         AMPLIFIER
                                                         AND METER
            Figure 24.  Gas cell correlation spectrometer analyzer.
                                      68

-------
                              -M
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 suitable  for  continuous  monitoring,  although  care must  be  taken  to maintain
 the monitored stream  at  constant  flow  rates.  A typical  NO and NO  analyzer
 f                                                                A
 is shown  in Figure  26.   In  this analyzer,  NO  molecules  combine with 03 to
 form an excited molecule (N02).   A photomultiplier detects photoemission decay
 and sends the signal  to  a sample-and-hold  circuit.  To  detect N02, a N02 and
 NO converter  is connected into the gas stream and the NO analysis is run again.
 After the second pass, a circuit  subtracts the first reading from the second
 to obtain the N02 reading.  Few interferences have been observed, but high
 concentrations of C02 or water vapor may partially quench the chemiluminescence.
 In addition to monitoring NO and  NOX, chemiluminescence devices are also used
 to detect 03  and S02.

 5.5  ELECTROCHEMICAL
     Analyzers using electrochemical  transducers measure the current induced
 by the electrochemical oxidation of the pollutant at a sensing electrode.
 Sensors are available for measuring Sp_2, CO, H2S, NO,  and N02.   Figure 27 shows
a simplified  schematic of an electrochemical transducer.  In this analyzer,
 the pollutant diffuses through the semipermeable membrane into  the transducer
at a rate proportional to the concentration.  At the sensing electrode,  the
pollutant undergoes an electrochemical  oxidation or reduction that causes a
current directly proportional  to the  partial pressure  of the gas  being monitored.
Since electrons are produced at the sensing electrode,  this electrode  is  at a
lower potential than the counter electrode.  Thus,  an  electron  current can
flow from the sensing electrode through the amplifier  to the counter electrode,
and the current will be proportional  to the concentration of the  pollutant.
                                     70

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  GAS CONTAINING POLLUTANT
  ...-L....1.....1...
I-I-I-I- SELECTIVE  MEMBRANE  -------
   THIN
FILM ELECTROLYTE
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      BULK ELECTROLYTE
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        Figure 27.  Electrochemical analyzer.
                       72

-------
                                   SECTION 6
                             PERFORMANCE TESTS AND
                  CONTINUOUS MONITOR PERFORMANCE EVALUATIONS
6.1  PERFORMANCE TESTS
     Compliance with the emission limitations of the NSPS is demonstrated
through performance tests conducted as required by Section 60.8.   The initial
performance tests are required within 60 days of achieving maximum production
rate, but no later than 180 days after initial startup.  The plant owner or
operator is required under Section 60.8(d) to provide at least 30 days prior
notice to the Administrator before conducting performance tests.   In addition,
the plant owner or operator must also notify the Administrator 30 days prior
to the expected date of initial startup and within 15 days of actual startup
that such is occurring.
     The test methods used by nitric acid plants in demonstrating compliance
are Method 7 for determination of NO  -concentration, Method 1 for sampling
                                    /\
point determination, Method 2 for determination of velocity and volumetric
flow rate, and Method 3 for gas analysis.  A copy of these Methods is pro-
vided in Appendix B.

6.2  PRETEST ARRANGEMENTS
     Field enforcement personnel should arrange a pretest meeting with respon-
sible plant personnel to review the methods of testing and regulatory require-
ments.  Although the  requirements are specified in the NSPS, this meeting
would clarify  the testing  requirements and avoid any potential misunderstanding
associated with  the testing requirements  during onsite testing.
      It  is recommended that a  pretest protocol be established that  sets  forth
certain  conditions  such  as production rate, acid strength,  the sampling
location(s), methods  to  be used, and  date(s)  of test(s).  A pretest  protocol
will  help  to address  any special circumstances that may  arise by  specifying
procedures  that  will  be  used.   The  objective  in establishing  this  protocol
                                      73

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 is to ensure that a representative performance test is  conducted  at  conditions
 representative of the nitric acid plant's  normal  operation.

 6.3  OBSERVING PERFORMANCE TESTS
      Agency personnel  observing  performance  tests  should  ensure themselves
 that the test is  conducted under representative conditions.  This does not
 require, however,  that the agency representative observe  the entire  stack
 sampling procedure to  determine  if each run  is  conducted  in accordance to the
 test method.   Agency personnel should be more  concerned with establishing
 that the nitric acid plant conditions are  representative  because the test
 methods  are relatively rigid  and the requirements  straight forward.
      The agency representative should observe,  at  the minimum, the following
 parameters  at the  nitric acid plant:
      1.   Ammonia  feed rate,
     2.
     3.
     4.
     5.
     6.
     7.
     8.
Air flow rate to ammonia burner,
Catalyst temperature at ammonia burner,
Bleach air flow rate,
Ammonia burner and absorption column pressure,
NOX concentration in tail gas,
Acid strength, and
Acid production rate (either at production strength or 100 percent
basis).  A material  balance should be performed to confirm
accuracy.
     In addition to these parameters, the operating temperatures, pressures,
flow rates, and any operating cycles associated with the control  equipment
should be noted.  Although many of these values are not directly  required
for the calculation of emission rates, they are useful  in establishing the
representativeness of any future performance tests and  in the evaluation of
operating conditions in followup inspections.
                                     74

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6.4  CONTINUOUS MONITOR PERFORMANCE EVALUATION
     Prior to conducting tests to determine compliance with the emission
limitations, Section 60.13 requires that the continuous monitor be installed
and operating.  The monitor must have completed the 168-h conditioning  period
specified in Performance Specification 2, Appendix B of the NSPS.   Section
60.13 also requires the continuous monitor to be certified through a  performance
evaluation, also in accordance with Performance Specification 2, within 30
days of any performance test required by Section 60.8; in addition, the
Administrator must be furnished with two copies of the report within  60 days
of the monitor evaluation.
     Briefly, the continuous monitor performance evaluation consists  of two
portions:  the conditioning period and the operating test period.   The  con-
ditioning period is 168 hours of continuous normal operation where negative
zero drift is quantified by offsetting the zero setting by 10 percent of  the
span.  The operating test period is the portion of the monitor performance
evaluation, 168 hours in duration, whe_re the monitor is calibrated and  checked
for accuracy, drift, and response time.
     The accuracy of the monitor is determined by comparing monitor output
values with values obtained by the performance test reference methods.   In
addition, the monitor calibration error is checked by comparison of the monitor
response with samples of known gas concentrations.  Monitor drift  is  checked
throughout the monitor test period as is monitor response time. The  monitor
requirements are summarized below.
6.4.1  Continuous Monitor Performance Specifications
     1.   Accuracy (error)
          Calibration (error)
     3.
     4.
     5.
Zero drift (2-h)
Zero drift (24-h)
£20 percent of mean value of reference
method test data (95 percent confidence
interval)
£5 percent of each (50 percent, 90 percent)
calibration gas mixture value
2 percent of span
2 percent of span
Calibration drift (2-h)   2 percent of span
                                      75

-------
     6.   Calibration drift
          (24-h)
     7.   Response time
     8.   Operational period
2.5 percent of span

15 min
168 h (minimum)
The span value for nitric acid plants subject to NSPS is 500 ppm NO  (measured
as N02).  Performance Specification 2 is presented in Appendix B of this
document.
     As in performance testing, the objective is to obtain a representative
and valid test.  Portions of the monitor performance evaluation may be con-
ducted concurrently with a performance test conducted under Section 60.8.  A
pretest protocol is highly recommended to familiarize the agency representative
with the scheduling of the various tests.  In addition to obtaining the produc-
tion data noted previously, the agency representative may wish to observe
various aspects of the test to observe the method in which each of the require-
ments is checked.  A schematic of the monitor sampling system and the operation
manual for the continuous monitor(s) may be useful  to the agency representative.
                                      76

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                                   SECTION 7
                             INSPECTION PROCEDURES

     Field enforcement personnel  must make periodic inspections  of the  nitric
acid production facilities.   It should be noted that a distinction is made
between a followup inspection and observation of the performance tests  although
the data obtained from each  are useful in determining the compliance status
of the plant.
     With the exception of performing visible emissions observations, a field
inspector can determine very little from physically examining the mechanical
components of the nitric acid process other than noting any major changes  in
equipment placement or fugitive emissions.  Although records kept by the
plant owner or operator will provide information to the field inspector so
that an evaluation of the compliance status and the effectiveness of the
maintenance may be conducted, the major emphasis of the inspection should  be
placed on reviewing continuous monitor outputs and operating records.

7.1  PLANT INSPECTION
7.1.1  Plant Entry
     Because a major emphasis is placed on using available records to  evaluate
the performance of the nitric acid plant, the plant management must be  con-
tacted.  The inspector should present his or her credentials and state  the
purpose of the inspection.   In the interview with plant management the  inspector
should be able to determine whether the plant is operating, the production
rate, and acid strength.
     It should be noted that some of the information obtained during the
inspections may be considered confidential by plant management.   Ammonia
feed rate, conversion efficiencies, and operating pressures are examples of
data that plant managers often consider confidential because of economic and
competitive reasons.  These data should be handled in the manner as directed
                                     77

-------
 by Section 114(c) of the Clean Air Act, which specifies the rights and respon-
 sibilities of field inspectors in obtaining confidential  data.   These data,
 however, when compared with the same data obtained during performance testing
 or continuous monitor performance evaluation, will allow the field inspector
 to assess if any significant change in plant operation has occurred.
 7.1.2  Inspection of the Plant
      After ascertaining that the nitric acid plant is  operating,  the  inspector
 should physically examine the plant.   The inspector should start  with  an
 evaluation of any visible emissions that are present at the tail  gas  stack.
 The inspector should also check for any obvious  changes in process  equipment
 that may affect plant operation.
      Proper operation of the continuous monitor  is extremely  important to
 the field inspector  in determining  the  existence of excess  emissions.  The
 inspection should include a  check of the following areas:
      1.    Is  the  monitor sited  at the same  point as  during  the monitor
           performance  evaluation and any previous  inspections?
      2.    Is  the  monitor the  same (same  model and  serial number) as the
           one tested  in  the most recent  performance  evaluation?
      3.    What is  the  location  of calibration gas  injection or the method
           of  required  daily calibration  checks?
     4.
What is the value of the span gas or cells used in  daily
calibration?
The continuous monitor display may be located near the analyzer or it may be
placed in the control room or both.  Typically the display will be in the
control room with the other process instrumentation.  A notation on the strip
chart may be useful to the inspector if data from the day of the inspection
is analyzed at a later date.
     At this point, the inspector should obtain the readings from the nitric
acid plant instrument panels.   This would include, if possible, the level  of
N02 in the tail  gas (ppm), the ammonia feed rate and/or the feed air volumetric
flow rate, the operating temperatures and pressures, and the operating
parameters monitored for any tail  gas control  device.   Comparison of these
values with the  baseline values established during the performance test can
                                      78

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aid in determining the compliance status.   Methods  for estimating  emission
rates are discussed in Section 7.2.
     The inspector should also review operator logs and maintenance  records
to determine if any problems are recurring that have an unfavorable  impact on
the emissions.  Daily production rates and operating hours  should  be scanned
to determine if the owner or operator is meeting or exceeding any  production
limitations or restrictions listed in an operating  permit.   In addition,  the
field inspector should determine if the production  rate is  relatively constant
and establish some value for average daily production.  Although the conversion
factors and figures presented in Section 7.2 are relatively accurate, the
field inspector may wish to use the individual conversion rates established
during the performance test for each nitric acid plant.
     If the inspector establishes from the operating records that  the nitric
acid production rate is relatively constant from day to day and establishes
an average value for production, the inspector may  also establish  a  value in
ppm NCL above which the NCL level exceeds  the standard of 1.5 kg/metric ton.
Establishing this level allows the inspector to quickly scan the data from the
continuous monitor strip charts to determine if any potential excess emission
period has occurred.  If a set of values is discovered above this  level,  the
production rate for those days should be used and not the average  value as
established above.
     This procedure will quickly identify  potential excess  emission  periods,
although it will not identify all of these periods.  This may only be
accomplished through checking the daily records and comparing the  averages of
each 3-h period with the specified emission limit indicated in ppm.
     The inspector will also need to verify that a  daily zero and  span cali-
bration check is performed.  This will usually be displayed as a square spike
on the strip chart.  The lack of daily zero and span calibration should be
noted for the periods when the monitor is  operating.  If the monitor does
not have an automatic zero and span calibration cycle, it is likely that the
daily zero and span calibrations may be missed.  If, however, the  monitor is
calibrated infrequently, then the data recorded on the monitor output may be
in error.  The options available to the field inspector are citing the owner
or operator for not performing daily calibration checks and requiring the
                                      79

-------
owner or operator to conduct a new performance evaluation of the monitor to
determine  if the monitor still fulfills the requirements of Performance Speci-
fication 2, Appendix B of the NSPS.
     As with most pieces of equipment, continuous monitors can and do fail.
The times  when the monitor is inoperative are required to be recorded (Section
60.7(c)(3}) along with a notation with respect to the nature of the repairs
and/or adjustments that were necessary to make the monitor operable again.
The agency must decide if the monitor downtime is excessive and what actions
should be  taken to remedy any problems with monitor operation.

7.2  ESTIMATION OF EMISSIONS FROM NITRIC ACID PLANTS
     An estimate of the tail gas volumetric flow rate within an accuracy of
+5 percent can be calculated from the air feed rate for an ammonia oxidation
nitric acid plant.  This is possible because the closed system design of the
pressure process allows no gas loss or gain from the beginning introduction
point to the exit exhaust stack.   The .oxygen content of the air is the only
component  in the air that is used in the reaction and it is carefully con-
trolled to an excess of approximately 2 to 5 percent.  Therefore,  a definite
ratio exists between the stack volumetric flow rate and the feed air volumetric
flow rate.  A small  portion (4 to 10 percent)  of the ammonia feed  is reduced
to inert nitrogen by the side reactions in the converter, but this amount is
relatively constant and does not significantly affect the ratio of stack flow
rate to feed air flow rate.
     Furthermore, with the ammonia efficiency  (sometimes expressed as nitrogen
efficiency) being constant,  the production rate of nitric acid (as 100 percent
concentration)  can also be estimated from the  air feed rate.   Because nitric
acid plants are usually run  at ammonia  efficiencies of between 90  to 95
percent,  an average of 93 can be  used.
     The  graphs shown in Figures  28 and 29 were constructed based  on the
average data reported for numerous nitric acid plants under various operating
conditions.  These graphs can be  used to estimate the stack volumetric flow
rate and  the plant emission  rate  in the following manner.
                                     80

-------
    100.0
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     10.0
      1.0
         100
                   1—I—I  I I I I
                    EMISSION RATE
                    (TAIL GAS)
                                                  AIR FEED RATE
1000                10,000

     AIR,  scf/h X 1000
100,000
                Figure 28.  Production  rate  vs.  air feed rate.
                                      81

-------
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                                             EFFICIENCY
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       10
              100
             1000
10,000
                            N0?,  ppm  (BY  VOL.)

                                 IN TAILGAS
Figure 29.
Conversion of NO  tail gas concentration  to  mass  emission.
                /\
                                  82

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     1.    Read the air flow rate to the converter (Fl,  usually in  standard
          cubic foot per hour (scf/h).

     2.    Read the bleach air flow rate (F2,  usually in scf/h).

     3.    Add the two air flows; this is the  total  air  to  the  process.   Assume
          this figure is 1,443,400 scf/h from Figure 28,  the plant production
          rate is 10 tons/h HMO, (100 percent) and  the  stack volumetric  flow
          rate is 1,209,000 scf/h.

     4.    Read the continuous nitrogen oxides monitor.— Assume it  reads  150
          ppm NOo; from Figure 29, the emission rate is 2.1 Ib N0?/ton HMO,
          (100 percent).

The graph shown in Figure 30 is useful  to check ammonia efficiency and/or

production rate when the plant ammonia feed rate is known.   Before using the

curves in Figure 30, one must know either the ammonia efficiency (nitrogen

efficiency) or accurate ammonia and production rate values.
                                     83

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  ioo.or
c
o
    i.o
                                             NITROGEN EFFICIENCY
     10,000
         100,000


AMMONIA FEED RATE,  scf/h
1,000,000
         Figure 30.   Ammonia  feed  rate vs. production rate.
                                84

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                                  REFERENCES
 1.   Chilton,  T.H.   The  Manufacture of Nitric  Acid By the  Oxidation  of  Ammonia,
     Chemical  Engineering  Progress  Monograph Series,  No. 3,  Volume 56,  1960.

 2.   Newman,  D.J.,  and L.A.  Klein.   Recent Developments  in Nitric Acid.
     Chemical  Engineering  Progress, No.  4, Volume 68, 1972.

 3.   Hellmer,  L.  Three  New  Nitric  Acid  Processes.  Chemical  Engineering
     Progress, No.  4,  Volume 68,  April  1972.

 4.   Reed,  R.M.,  and R.L.  Marvin.   Nitric Acid Plant Fume  Abaters.   Chemical
     Engineering  Progress, No.  4, Volume 68, April 1972.

 5.   Andrussow, L., and  Z. Angew.   Chem., Vol. 39, No.  321 (1926); Vol. 40,
     No.  166,  1927.

 6.   Fauser,  G.  Chem. Met.  Eng., Vol7'35, No. 474, 1928.

 7.   Bodenstein,  M.Z.   Elektrochem., Vol. 24,  No. 183,  1918.

 8.   Newman,  D.J.  Nitric  Acid  Plant Pollutants.   Chemical Engineering
     Progress, Vol. 67,  No.  2,  February 1971.

 9.   U.S.  Environmental  Protection  Agency.  Control of Air Pollution From
     Nitric Acid Plants.  Draft.  August, 1971.

10.   Chem.  Eng.,  Vol.  59,  No. 1,  238.  1952.

11.   U.S.  Environmental  Protection  Agency.  Review of New  Source Performance
     Standards for  Nitric  Acid  Plants.  EPA 450/8-84-011,  April  1984.

12.   Gillespie, G.R.,  A.A. Boyum,  and M.F. Collins.  Catalytic Purification
     of Tail  Gases.  Chemical Engineering Progress, No.  4, Volume  68, April
     1972.

13.   Snyder, A.D.,  et al.   Monsanto Research Corporation.   Instrumentation
     for the Determination of Nitrogen Oxides  Content of Stationary  Source
     Emissions.

14.   U.S.  Environmental  Protection  Agency.  An Air Pollution Compliance
     Analysis Report on  Nine Industries.  Volume V.  Nitric Acid Industry,
     Final  Report,  September 1978.
                                     85

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15.  Drabkin, M.  A Review of Standards of Performance for New Stationary
     Sources - Nitric Acid Plants.  MITRE Technical Report - 7911.  EPA
     Contract No. 68-02-2526, January 1979.

16.  MASAR Process for Recovery of Nitrogen Oxides.  Company brochure, MASAR,
     Inc.

17.  NOX Abatement in Nitric Acid and Nitric Phosphate Plants.  Nitrogen,
     No. 93, January/February 1975.

18.  Service, W.J., R.T. Schneider, and D. Ethington.  The Goodpasture
     Process for Chemical Abatement and Recovery of NOX.  Conference on
     Gaseous Sulfur and Nitrogen Compound Emissions, Salford, England,
     April 1976.

19.  U.S. Environmental Protection Agency.  Control Techniques for Nitrogen
     Oxides Emissions from Stationary Sources (2nd ed.).   EPA-450/1-78-001,
     January 1978.

20.  Gerstle, R.W., and R.F.  Peterson.  Atmospheric Emissions from Nitric Acid
     Manufacturing Process.  National Center for Air Pollution Control,
     Cincinnati, Ohio, PHS Publication Number 999-AP-27, 1966.

21;  Rosenberg, H.S.   Molecular SieveJIOx Control Process in Nitric Acid
     Plants.  Environmental Protection Technology Series, EPA-600/2-76-015,
     January 1976.

22.  Chehaske,  J.I.,  and J.S. Greenberg.   Molecular Sieve Tests for Control
     of NOX Emissions from a  Nitric Acid  Plant.   Volume I, EPA-600/2-76-048a,
     March 1976.

23.  Bolme, D.W., and A.M.  Bolme and Associates.  The Humphreys and Glasgow/
     Bolme Nitric Acid Process.   Chemical  Engineering Progress, p. 95-98,
     March 1979.
                                      86

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   APPENDIX A



NSPS REGULATIONS
      87

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Chapter I—Environmental Protection Agency
§60.71
                           Subpart G—Standards of
                       Performance for Nitric Acid Plants

                     §60.70  Applicability  and designation of
                        affected facility.
                       (a) The  provisions  of this subpart
                     are applicable to each nitric acid pro-
                     duction unit, which is the affected fa-
                     cility.
                       (b) Any facility  under paragraph (a)
                     of this section that commences con-
                     struction or modification after August
                     17, 1971, is.subject to the requirements
                     of this subpart.
                     (Sees. Ill and 301(a) of the Clean Air Act;
                     sec. 4(a) of Pub. L. 91-604, 84 Stat. 1683: sec.
                     2 of Pub. L. 90-148.-81 Stat. 504 (42 U.S.C.
                     1857C-6. 1857g(a)))
                     [42 PR 37936, July 25, 1977]

                     § 60.71  Definitions.
                       As used in this subpart, all terms not
                     defined herein shall have the meaning
                     given them in the Act and in Subpart
                     A of this part.
                                      88

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 § 60.72
   Title 40—Protection of Environment
  (a)  "Nitric  acid  production  unit"
 means any  facility  producing  weak
 nitric acid by either the pressure or at-
 mospheric pressure process.
  (b)  "Weak nitric  acid"  means acid
 which is 30 to 70 percent  in strength.

 § 60.72  Standard for nitrogen oxides.
  (a) On and after the date on which
 the performance test  required  to be
 conducted by  § 60.8  is completed, no
 owner or operator subject to the provi-
 sions of this subpart shall cause to be
 discharged into the atmosphere from
 any affected facility  any gases which:
  (1)  Contain  nitrogen  oxides,  ex-
 pressed as NO,, in excess of 1.5 kg per
 metric ton of acid produced (3.0 Ib per
 ton), the production being expressed
 as 100 percent nitric acid.
  (2) Exhibit  10  percent  opacity, or
 greater.

 [39 PR 20794,  June 14, 1974, as amended at
 40 PR 46258, Oct. 6, 1975]

 § 60.73  Emission monitoring.
  (a) A continuous monitoring system"
 for  the  measurement of  nitrogen
 oxides  shall be  installed, calibrated,
 maintained,  and  operated  by  the
 owner or  operator. The pollutant  gas
 used to prepare calibration gas mix-
 tures  under  paragraph 2.1,  Perform-
 ance Specification 2  and  for calibra-
 tion checks  under § 60.13(d) to  this
 part, shall be nitrogen dioxide (NO,).
 The span shall be set  at 500 ppm of ni-
 trogen dioxide. Reference Method 7
 shall be used for conducting monitor-
 ing  system  performance  evaluations
 under § 60.13(c).
  (b) The owner or operator shall es-
 tablish a conversion factor for the pur-
 pose  of converting monitoring  data
 into units  of the applicable standard
 (kg/metric ton,  Ib/short  ton).  The
 conversion factor shall be  established
 by measuring emissions with the con-
 tinuous monitoring system concurrent
 with measuring emissions with the ap-
 plicable reference method tests. Using
 only that  portion of  the  continuous
monitoring emission data  that repre-
sents emission  measurements concur-
rent with  the  reference method  test
periods, the conversion factor shall be
determined by  dividing the reference
method test data averages by the mon-
itoring data averages  to obtain a  ratio
 expressed in units of the applicable
 standard to units of the monitoring
 data, i.e., kg/metric ton per ppm (Ib/
 short  ton per ppm).  The conversion
 factor  shall be  reestablished  during
 any performance test under § 60.8 or
 any  continuous  monitoring  system
 performance     evaluation     under
 § 60.13(0.
  (c) The  owner  or operator  shall
 record  the  daily production rate and
 hours of operation.
  (d) [Reserved]
  (e) For the  purpose of reports re-
 quired   under  § 60.7(c),  periods  of
 excess emissions that shall be reported
 are  defined  as  any  3-hour  period
 during  which  the  average nitrogen
 oxides  emissions  (arithmetic average
 of three contiguous 1-hour periods) as
 measured by a continuous monitoring
 system  exceed the  standard  under
 § 60.72(a).

 (Sec. 114,  Clean Air Act as  amended (42
 U.S.C. 7414))
 [39 PR 20794, June 14, 1974. as amended at
 40 PR 46258,  Oct. 6, 1975; 43 PR 8800. Mar
 3, 1978]

 § 60.74   Test  methods and procedures.
  (a) The reference methods in Appen-
 dix A to this part, except  as provided
 for in § 60.8(b), shall be used to deter-
 mine compliance  with  the  standard
 prescribed in § 60.72 as follows:
  (1) Method 7 for the concentration
 of NOr;
  (2) Method 1  for sample and velocity
 traverses;
  (3) Method 2 for velocity and  volu-
 metric flow rate; and
  (4) Method 3  for gas analysis.
  (b) For Method 7, the sample site
 shall be selected according to Method
 1 and the sampling point shall be the
 centroid of  the stack or duct or at a
 point no closer to the walls than  1 m
 (3.28 ft). Each  run shall consist of at
 least four grab samples taken at ap-
 proximately 15-minute intervals. The
 arithmetic mean of the samples shall
constitute the  run value.  A  velocity
 traverse shall be performed  once per
run.
 (c) Acid production rate, expressed
in metric tons per hour of 100 percent
nitric acid, shall be determined during
each testing period by suitable meth-
                                    89

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 Chapter I—Environmental Protection Agency
                                  § 60.84
 ods and shall be confirmed by a mate-
 rial  balance  over  the  production
 system.
   (d) For each run,  nitrogen oxides,
 expressed in g/metric ton of 100 per-
 cent nitric acid, shall be determined by
 dividing the  emission rate in g/hr by
 the acid production rate. The emission
 rate shall be determined by  the equa-
 tion,
              g/hr=Q.xc
 where  Q,=volumetric flow rate of the
 effluent in dscm/hr, as determined in
 accordance with  paragraph  (a)(3) of
 this section, and c=NOx concentration
 in g/dscm, as  determined in accord-
 ance with paragraph (aXl) of this sec-
 tion.

 (Sec. 114, Clean  Air Act as amended (42
 U.S.C. 7414))
 [39 PR 20794. June 14. 1974. as amended at
 43 PR 8800, Mar. 3, 1978]
       Subpart H—Standards of
  Performance for Sulfuric Acid Plants
§ 60.80  Applicability  and designation of
    affected facility.
  (a) The provisions  of this  subpart
are  applicable  to  each sulfuric acid
production unit, which is the affected
facility.
  (b) Any facility under paragraph (a)
of this section that commences con-
struction or modification after August
17, 1971, is subject to the requirements
of this subpart.

(Sees, ill and 301(a) of the Clean Air Act;
sec. 4(a) of Pub. L. 91-604, 84 Stat. 1683; sec.
2 Of Pub. L. 90-148, 81 Stat. 504 (42 U.S.C.
1857C-6, 1857g(a»)
C42 PR 37936, July 25, 1977]

§ 60.81  Definitions.
  As used in this subpart, all terms not
defined herein shall have the meaning
given them in the Act and in Subpart
A of this part.
  (a)  "Sulfuric  acid production  unit"
means any facility producing sulfuric
acid by the contact process by burning
elemental sulfur, alkylation acid, hy-
drogen  sulfide, organic sulfides and
mercaptans, or acid sludge, but does
not include facilities where conversion
to sulfuric acid is utilized primarily as
a means of preventing emissions to the
    atmosphere of sulfur dioxide or other
    sulfur compounds.
      (b)  "Acid  mist"  means sulfuric  acid
    mist,  as measured by Method 8 of Ap-
    pendix A to this part or an equivalent
    or alternative method.

    [36 PR 24877, Dec. 23, 1971, as amended at
    39 PR 20794, June 14, 1974]

    § 60.82  Standard for sulfur dioxide.
      (a) On and after the date on which
    the performance test required to be
    conducted by § 60.8 is completed, no
    owner or operator subject to the provi-
    sions of this subpart shall  cause to be
    discharged into the atmosphere from
    any affected facility any gases which
    contain sulfur dioxide in excess of 2 kg
    per metric ton of  acid produced (4 Ib
    per ton),  the  production  being  ex-
    pressed as 100 percent H2SO«.

    [39 PR 20794,  June 14, 1974]
_.   § 60.83  Standard for acid mist.
     (a) On and after the date on which
    the performance test  required  to be
    conducted by  § 60.8  is completed, no
    owner or operator subject to the provi-
    sions of this subpart shall cause to be
    discharged into the atmosphere from
    any affected facility  any gases which:
     (1) Contain acid mist,  expressed as
    HjSO,, in excess of 0.075 kg per metric
    ton of acid produced (0.15 Ib per ton),
    the production being expressed as 100
    percent HjSO,.
     (2) Exhibit 10  percent opacity, or
    greater.

    [39 PR 20794, June 14, 1974, as amended at
    40 PR 46258, Oct. 6, 1975]

    § 60.84 Emission monitoring.
     (a) A continuous monitoring system
    for the measurement of sulfur dioxide
    shall be installed,  calibrated, main-
    tained, and operated by the owner or
    operator. The pollutant  gas used to
    prepare   calibration   gas   mixtures
    under paragraph  2.1,   Performance
    Specification  2  and  for calibration
    checks under § 60.13(d), shall be sulfur
    dioxide  (SO,). Reference Method 8
    shall be  used  for conducting monitor-
    ing  system performance  evaluations
    under § 60.13(c) except that only  the
    sulfur dioxide portion of the  Method 8
                                    90

-------
§ 60.85

results shall be used. The  span shall
be set at 1000 ppm of sulfur dioxide.
  (b) The owner or operator shall es-
tablish a conversion factor for the pur-
pose of  converting  monitoring  data
into units  of the applicable standard
(kg/metric  ton,  Ib/short  ton).  The
conversion factor shall be determined,
as a minimum, three  times  daily by
measuring the  concentration of sulfur
dioxide entering the  converter  using
suitable methods (e.g., the Reich test,
National Air Pollution Control Admin-
istration Publication  No. 999-AP-13)
and calculating the appropriate con-
version  factor  for  each  eight-hour
period as follows:
        CF=kC1.000-0.015r/r-s]
where:
  CP =.conversion factor (kg/metric ton per
     ppm, Ib/short ton per ppm).
  lc =constant derived from material bal-
     ance. For determining CF  in  metric
     units, k=0.0653.  For determining CF
     in English units, k=0.1306.
  r = percentage of sulfur dioxide by volume
     entering the gas converter. Appropri-
     ate corrections must be made for air
     injection plants subject to the Admin-
     istrator's approval.
  s = percentage of sulfur dioxide by volume
     in the emissions to the atmosphere de-
     termined by the continuous monitor-
     ing system  required under paragraph
     (a) of this section.
  (c)  The  owner  or  operator  shall
record  all   conversion  factors  and
values under paragraph (b)  of this sec-
tion from which they were computed
(i.e., CP, r, and s).
  (d) [Reserved]
  (e) For the purpose of reports under
§ 60.7(c), periods  of excess emissions
shall be  all three-hour periods (or the
arithmetic average  of three  consecu-
tive one-hour  periods) during which
the integrated average sulfur dioxide
emissions exceed the applicable stand-
ards under § 60.82.
(Sec. 114, Clean Air Act as amended (42
U.S.C. 7414))
139 PR 20794, June 14. 1974, as amended at
40 FR 46258, Oct. 6, 1975; 43 PR 8800, Mar.
3, 1978]

§ 60.85  Test methods and procedures.
  (a) The reference methods in Appen-
dix A to this part, except as provided
for in  § 60.8(b), shall be used to deter-
mine compliance with the  standards
  Title 40—Protection of Environment

prescribed  in §§ 60.82 and 60.83 as fol-
lows:
  (1) Method 8 for the concentrations
of SO, and acid mist;
  (2) Method 1 for sample and velocity
traverses;
  (3) Method  2  for velocity and volu-
metric flow rate; and
  (4) Method 3 for gas analysis.
  (b) The moisture content can be con-
sidered  to  be  zero. For Method  8  the
sampling time for each run shall be at
least  60 minutes and  the  minimum
sample volume shall be 1.15 dscm (40.6
dscf)  except  that smaller sampling
times or sample volumes, when neces-
sitated  by  process variables or  other
factors, may be approved by the  Ad-
ministrator.
  (c) Acid  production rate,  expressed
in metric tons per hour of 100 percent
H,SO,,  shall  be  determined during
each testing period by suitable meth-
ods and shall be confirmed by a mate-
rial  balance   over  the   production
system.
  (d)  Acid  mist  and  sulfur  dioxide
emissions, expressed in g/metric ton of
100  percent  HjSO«,  shall  be  deter-
mined by dividing the emission rate in
g/hr by  the acid production rate. The
emission rate shall be  determined by
the   equation,   g/hr=Q,xc,   where
Q,=volumetric flow rate of the  efflu-
ent in dscm/hr as determined in ac-
cordance with paragraph (a)(3) of  this
section, and c=acid mist and SO3 con-
centrations in g/dscm  as determined
in accordance with paragraph (aXI) of
this section.
(Sec. 114, Clean  Air Act as amended (42
U.S.C. 7414))
[39  FR 20794. June 14, 1974, as amended at
43 FR 8800, Mar. 3, 1978]

Subpart I—Standards of Performance
     for Asphalt Concrete Plants

§ 60.90  Applicability and  designation of
    affected facility.
  (a)  The  affected  facility to  which
the provisions of this subpart apply is
each asphalt  concrete  plant. For  the
purpose  of this subpart, an  asphalt
concrete plant  is comprised only of
any combination  of  the  following:
Dryers;  systems for screening,  han-
dling, storing, and weighing hot aggre-
                                    91

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Chapter I—Environmental Protection Agency
                             §60.101
gate; systems for loading, transferring,
and storing mineral filler; systems for
mixing asphalt concrete; and the load-
ing, transfer, and storage systems asso-
ciated with emission control systems.
  (b) Any facility under paragraph (a)
of  this section that commences con-
struction or modification  after June
11, 1973, is subject to the requirements
of this subpart.

(Sees. Ill and 301(a) of the Clean Air Act;
sec. 4(a) of Pub. L. 91-604, 84 Stat. 1683; sec.
2 of Pub. L. 90-148, 81 Stat. 504 (42 U.S.C.
1857C-6,1857g(a»)
C42 FR 37936, July 25, 1977]

§ 60.91   Definitions.
  As used in this subpart, all terms not
defined herein shall have the meaning
given them in  the Act and in Subpart
A of this part.
  (a) "Asphalt concrete plant" means
any facility, as  described in § 60.90,
used to manufacture asphalt concrete
by  heating and drying aggregate and"
mixing with asphalt cements.

§ 60.92  Standard for particulate matter.
  (a) On and after the date on which
the  performance test required  to be
conducted by  § 60.8  is completed, no
owner or operator subject to the provi-
sions of this subpart shall discharge or
cause  the discharge into  the  atmos-
phere  from any  affected  facility any
gases which:
  (1) Contain  particulate  matter  in
excess of 90 mg/dscm (0.04 gr/dscf).
  (2) Exhibit  20 percent  opacity,  or
greater.
C39  FR 9314, Mar. 8, 1974, as amended at 40
FR 46259, Oct. 6, 1975]

§ 60.93  Test methods and procedures.
  (a) The reference methods appended
to this part,  except as provided  for in
§ 60.8(b),  shall be  used to  determine
compliance with the standards pre-
scribed in § 60.92 as follows:'
  (1) Method 5 for the  concentration
of particulate matter and the associat-
ed moisture content,
  (2) Method 1 for sample and velocity
traverses,
  (3) Method 2 for velocity and volu-
metric flow rate, and
  (4) Method 3 for gas analysis.
  (b) For Method 5, the sampling time
for each run shall  be at least 60 min-
utes and the sampling rate shall be at
least   0.9  dscm/hr  (0.53   dscf/min)
except  that shorter sampling times,
when necessitated by process variables
or other factors, may be approved by
the Administrator.
(Sec. 114, Clean Air Act as  amended (42
U.S.C. 7414))
[39 FR 9314, Mar. 8, 1974, as amended at 43
FR 8800, Mar. 3, 1978]

Subpart J—Standards of Performance
       for  Petroleum Refineries

§ 60.100  Applicability and designation  of
   affected facility.
  (a)  The  provisions  of this  subpart
are applicable to the following affect-
ed facilities in petroleum refineries:
fluid  catalytic  cracking unit  catalyst
regenerators, fuel  gas combustion de-
vices, and all  Glaus  sulfur  recovery
plants except Glaus plants of 20 long
tons per day (LTD) or less. The Glaus
sulfur recovery  plant need  not be
physically  located  within  the bound-
aries of a petroleum refinery to be an
affected facility, provided  it processes
gases produced within a petroleum re-
finery.
  (b) Any fluid catalytic cracking unit
catalyst regenerator or fuel gas com-
bustion device under paragraph (a)  of
this  section which  commences  con-
struction  or modification  after June
11, 1973, or any Glaus sulfur recovery
plant under paragraph (a) of this sec-
tion which commences construction  or
modification after  October 4, 1976, is
subject to  the  requirements  of this
part.
(Sees.  Ill,  114, 301(a), Clean Air Act,  as
amended (42 U.S.C. 7411, 7414, 7601(a)))
[43 FR 10868, Mar. 15, 1978, as amended at
44 FR 61543, Oct. 25, 1979]

§ 60.101  Definitions.
  As used in this subpart, all terms not
defined herein shall have the meaning
given them in the Act and in Subpart
A.
  (a) "Petroleum refinery" means any
facility engaged in  producing gasoline,
kerosene, distillate  fuel oils, residual
fuel oils, lubricants, or other products
                                    92

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Chapter I—Environmental Protection Agency
                              §60.2
   Subpart A—General Provisions

§ 60.1  Applicability.
  Except as  provided  in  Subparts B
and  C, the  provisions of  this  part
apply to the owner or operator of any
stationary source  which  contains  an
affected facility, the construction  or
modification  of which is commenced
after  the  date of publication in this
part of any standard (or, if earlier, the
date of publication of any  proposed
standard) applicable to that facility.

[40 PR 53346, Nov. 17, 1975]

§ 60.2  Definitions.
  The terms used  in this  part are de-
fined  in the Act or in this section as
follows:
  "Act" means the Clean Air Act (42
U.S.G. 1857 et  seq.,  as  amended  by
Pub. L. 91-604, 84 Stat. 1676).
  "Administrator" means the Adminis~-'
trator  of  the Environmental Protec-
tion Agency  or his authorized repre-
sentative.
  "Affected facility" means,  with ref-
erence to a stationary source, any ap-
paratus to which a standard is applica-
ble.
  "Alternative  method"  means  any
method of sampling and analyzing for
an air pollutant which is not a refer-
ence or equivalent method but which
has been demonstrated to the Admin-
istrator's  satisfaction  to,  in specific
cases, produce results adequate for his
determination of compliance.
  "Capital expenditure" means an ex-
penditure for a physical or operational
change to  an existing facility which
exceeds the product of the applicable
"annual asset guideline  repair allow-
ance  percentage"  specified  in   the
latest  edition  of  Internal  Revenue
Service (IRS)  Publication 534 and the
existing facility's basis, as defined  by
section 1012  of  the Internal Revenue
 Code. However, the total expenditure
 for a physical or operational change to
an  existing facility  must  not be re-
duced by any "excluded additions" as
defined in  IRS  Publication  534,  as
would be done for tax purposes.
  "Commenced" means, with respect
to the definition of  "new source" in
section  lll(a)(2)  of  the Act,  that an
owner  or operator  has undertaken  a
continuous program of construction or
modification or that an owner or oper-
ator has entered into  a contractual ob-
ligation to  undertake  and complete,
within a reasonable time, a continuous
program of construction or modifica-
tion.
  "Construction"  means  fabrication,
erection, or installation of  an  affected
facility.
  "Continuous   monitoring   system"
means the  total  equipment, required
under  the  emission  monitoring sec-
tions in applicable subparts,  used to
sample  and condition (if applicable),
to analyze,  and to provide a perma-
nent record of emissions or process pa-
rameters.
  "Equivalent  method"  means  any
method of sampling and analyzing for
an air  pollutant which  has been dem-
onstrated to the Administrator's satis-
faction to have a consistent and quan-
titatively  known relationship to  the
reference method, under specified con-
ditions.
  "Existing facility" means, with refer-
ence to a stationary source, any appa-
ratus of the type for which a standard
is promulgated in this part,  and  the
construction or modification of which
was  commenced  before the  date  of
proposal of that standard; or any ap-
paratus which could be  altered in such
a way as to be of that type.
  "Isokinetic  sampling" means sam-
pling in which the linear velocity of
the gas entering the sampling nozzle is
equal to that of  the undisturbed gas
stream at the sample point.
  "Malfunction"  means any sudden
and  unavoidable  failure of air  pollu-
tion control  equipment  or  process
equipment or of  a process to operate
in a normal or usual manner.  Failures
that are caused entirely or in part by
poor maintenance, careless operation,
or any other preventable upset condi-
tion or preventable equipment break-
down shall not be considered malfunc-
tions.
                                   93

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§60.3
   Title 40—Protection of Environment
  "Modification" means any physical
change in, or chanse in the method of
operation of, an existing facility which
increases the amount of any air pollut-
ant (to which a standard applies) emit-
ted into the atmosphere by that facili-
ty or which results in the emission of
any air pollutant (to which a standard
applies) into the atmosphere not pre-
viously emitted.
  "Monitoring device" means the total
equipment,  required under the moni-
toring of  operations sections in appli-
cable subparts,  used  to measure and
record (if applicable)  process param-
eters.
  "Nitrogen oxides" means all oxides
of nitrogen except nitrous oxide,  as
measured by test methods set forth in
this part.
  "One-hour period" means any  60-
minute period  commencing  on  the
hour.
  "Opacity"  means  the  degree  to
which emissions reduce the transmis-\
sion of light and obscure the view of"
an object in the background.
  "Owner  or operator"  means any
person who owns, leases, operates, con-
trols, or supervises an affected facility
or a stationary source of which  an af-
fected facility is a part.
  "Particulate  matter"   means  any
finely divided solid or liquid material,
other  than  uncombined water,  as
measured by the reference methods
specified under each applicable sub-
part,  or  an equivalent  or alternative
method.
  "Proportional sampling" means sam-
pling at  a rate that produces  a con-
stant ration of sampling rate to stack
gas flow rate.
  "Reference  method"   means  any
method of sampling and analyzing for
an air pollutant as described in Appen-
dix A to this part.
  "Run" means the net period of time
during which an  emission sample is
collected. Unless otherwise specified, a
run may be either intermittent or con-
tinuous within the limits of good engi-
neering practice.
  "Shutdown" means the cessation of
operation of an  affected  facility  for
any purpose.
  "Six-minute period" means any one
of the 10 equal  parts  of  a one-hour
period.
  "Standard" means a standard of per-
formance  proposed or  promulgated
under this part.
  "Standard conditions" means a tem-
perature of 293 K (68°P) and  a  pres-
sure of  101.3 kilopascals (29.92  in Hg).
  "Startup" means the setting in oper-
ation of an affected facility for any
purpose.
  "Volatile Organic Compound" means
any  organic compound which  partici-
pates in  atmospheric photochemical
reactions; or which  is measured  by a
reference  method,   an   equivalent
method, an  alternative  method,  or
which  is determined  by  procedures
specified under any subpart.

[44 FR 55173, Sept. 25, 1979, as amended at
45 FR 5617, Jan. 23, 1980; 45 FR 85415, Dec.
24, 1980]

§ 60.3 Units and abbreviations.

  Used in this  part are abbreviations
and  symbols  of  units  of  measure.
These are defined as follows:
  (a) System International (SI) units
of measure:

A—ampere
g—gram
Hz—hertz
J—joule
K—degree Kelvin
kg—kilogram
m—meter
m3—cubic meter
mg—milligram—10"3 gram
mm—millimeter—10"3 meter
Mg—megagram—106 gram
mol—mole
N—newton
ng—nanogram—10"9 gram
nm—nanometer—10"» meter
Pa—pascal
s—second
V—volt
W—watt
ft—ohm
Hg—microgram—10"6 gram

  (b) Other units of measure:

Btu—British thermal unit
°C—degree Celsius (centigrade)
cal—calorie
cfm—cubic feet per minute
cu ft—cubic feet
dcf—dry cubic feet
dcm—dry cubic meter
dscf—dry cubic feet at standard conditions
dscm—dry cubic meter at standard condi-
  tions
eq—equivalent
                                    94

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Chapter I—Environmental Protection Agency
                                  §60.4
°F—degree Fahrenheit
ft—feet
gal—gallon
gr—grain
g-eq—gram equivalent
hr—hour
in—inch
k—1,000
1—liter
1pm—liter per minute
Ib—pound
meq—milliequivalent
min—minute
ml—milliliter
mol. wt.—molecular weight
ppb—parts per billion
ppm—parts per million
psia—pounds per square inch absolute
psig—pounds per square inch gage
°R—degree Rankine
scf—cubic feet at standard conditions
scfh—cubic feet per hour at standard condi-
  tions
scm—cubic meter at standard conditions
sec—second
sq ft—square feet
std—at standard conditions

  (c) Chemical nomenclature:

CdS—cadmium sulfide
CO—carbon monoxide
COs—carbon dioxide
HC1—hydrochloric acid
Hg—mercury
HaO—water
H,S—hydrogen sulfide
HjSO*—sulfuric acid
N3—nitrogen
NO—nitric oxide
NO,—nitrogen dioxide
NO,—nitrogen oxides
O,—oxygen
SO,—sulfur dioxide
SO,—sulfur trioxide
SO,—sulfur oxides

  (d) Miscellaneous:

A.S.T.M.—American Society for Testing and
  Materials

(Sees. Ill and 301
-------
 §60.4
   Title 40—Protection of Environment
 sion. 645 S. McDonough Street, Montgom-
 ery, Alabama 36104.
   (C) [Reserved]
   (D) Arizona:
   Maricopa County Department of Health
 Services. Bureau of Air Pollution  Control,
 1825 East  Roosevelt  Street, Phoenix, AZ
 85006.
   Pima  County Health  Department,  Air
 Quality Control District, 151 West Congress,
 Tucson, AZ 85701.
   Pima County Air Pollution Control Dis-
 trict, 151 West Congress Street,  Tucson, AZ
 85701.
   (E) [Reserved]
   (F) California:
 Bay Area Air Pollution Control District, 939
   Ellis Street, San Francisco, CA 94109.
 Del Norte County Air Pollution Control Dis-
   trict,  Courthouse,  Crescent   City,  CA
   95531.
 Frensno County Air Pollution Control Dis-
   trict, 515 S.  Cedar  Avenue,  Fresno,  CA
   93702.
 Humboldt County  Air  Pollution  Control
   District, 5600 S.  Broadway, Eureka,  CA
   95501.
 Kern County Air Pollution Control District,
   1700 Flower Street (P.O. Box 997), Bakers-""
   field. CA 93302.
 Madera County Air Pollution Control Dis-
   trict,  135 W. Yosemite Avenue, Madera,
  CA 93637.
 Mendocino  County  Air  Pollution  Control
  District. County Courthouse,  Ukiah,  CA
  95482.
 Monterey Bay Unified Air Pollution Control
  District, 420 Church Street (P.O. Box 487)
  Salinas, CA 93901.
 Northern  Sonoma  County  Air Pollution
  Control  District,  3313  Chanate  Road,
  Santa Rosa, CA 95404.
 Sacramento County Air Pollution  Control
  District, 3701  Branch Center Road, Sacra-
  mento, CA 95827.
 San Diego  County Air  Pollution  Control
  District,  9150  Chesapeake Drive,  San
  Diego. CA 92123.
 San Joaquin County Air Pollution  Control
  District,  1601 E, Hazelton Street  (P.O.
  Box 2009) Stockton, CA 95201.
 Santa  Barbara  County Air Pollution Con-
  trol District, 4440 Calle Real,  Santa Bar-
  bara, CA 93110.
Shasta  County Air Pollution Control Dis-
  trict.  1855 Placer Street,  Redding, CA
  96001.
South  Coast Air Quality Management Dis-
  trict, 9420 Telstar Avenue, El  Monte, CA
  91731.
Stanislaus County  Air Pollution Control
  District,  820  Scenic  Drive,  Modesto, CA
  95350.
Trinity County Air Pollution Control Dis-
  trict, Box AJ, Weaverville, CA 96093.
Ventura County Air Pollution Control Dis-
  trict, 625 E. Santa Clara Street, Ventura.
  CA 93001.
  (G) State of Colorado, Colorado Air Pollu-
tion  Control  Division,  4210  East  llth
Avenue, Denver, Colorado 80220.
  (H) State of Connecticut, Department of
Environmental  Protection,   State  Office
Building, Hartford, Connecticut 06115.
  (I) State of Delaware (for fossil fuel-fired
steam generators;  incinerators; nitric acid
plants; asphalt concrete plants; storage ves-
sels for petroleum liquids;  sulfuric  acid
plants;  sewage treatment plants; and elec-
tric utility steam generating units), Dela-
ware Department of Natural  Resources and
Environmental  Control,  Edward  Tatnall
Building, Dover Delaware 19901.
  (J)—(K)  [Reserved]
  (L) State of Georgia, Environmental Pro-
tection Division, Department of Natural Re-
sources, 270  Washington  Street, S.W.,  At-
lanta, Georgia 30334.
  (M) [Reserved]
  (N) State of Idaho, Department of Health
and Welfare,  Statehouse,  Boise,  Idaho
83701.
  (O) [Reserved]
  (P) State of  Indiana, Indiana Air Pollu-
tion Control Board,  1330 West Michigan
Street, Indianapolis, Indiana 46206.
  (Q) State of Iowa, Iowa Department  of
Environmental Quality, Henry A.  Wallace
Building, 900 East Grand, Des Moines, Iowa
50316.
  (R) [Reserved]
  (S) Division of Air Pollution Control, De-
partment for Natural  Resources and Envi-
ronmental  Protection,  U.S. 127, Frankfort,
Ky. 40601.
  (T) [Reserved]
  (U) State of Maine, Department of Envi-
ronmental  Protection,  State House,  Augus-
ta, Maine 04330.
  (V) State of  Maryland:  Bureau  of Air
Quality and Noise Control, Maryland State
Department of Health  and Mental Hygiene,
201 West Preston  Street, Baltimore, Mary-
land 21201.
  (W) Massachusetts Department  of Envi-
ronmental  Quality Engineering. Division  of
Air Quality Control, 600 Washington Street,
Boston, Massachusetts 02111.
  (X) State of Michigan, Air Pollution Con-
trol Division.  Michigan Department of Nat-
ural Resources, Stevens T. Mason Building,
8th Floor, Lansing, Michigan 48926.
  (T) Minnesota Pollution Control Agency,
Division of Air Quality, 1935 West  County
Road B-2, Roseville, Minn. 55113.
  (Z) [Reserved]
                                         96

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 Chapter I—Environmental Protection Agency
                                  §60.4
  (AA) Missouri Department of Natural Re-
sources, Post  Office  Box  1368, Jefferson
City, Missouri 65101.
  (BB) State of Montana, Department of
Health and Environmental Services, Cogs-
well Building, Helena, Mont. 59601.
  (CO Nebraska  Department of Environ-
mental  Control,  P.O.  Box  94653,  State
House Station, Lincoln, Nebraska 68509.
  (DD) Nevada:
Nevada Department of Conservation  and
  Natural  Resources,  Division of Environ-
  mental Protection, 201 South Pall Street,
  Carson City, NV 89710.
Clark County  County  District Health De-
  partment, Air Pollution Control Division,
  625 Shadow Lane, Las Vegas, NV 89106.
Washoe County  District  Health  Depart-
  ment, Division of Environmental Protec-
  tion, 10 Kirman Avenue, Reno, NV 89502.
  (EE) New Hampshire Air Pollution  Con-
trol Agency, Department  of Health  and
Welfare, State Laboratory Building, Hazen
Drive, Concord, New Hampshire 03301.
  (FF) State of New Jersey: New Jersey De-
partment   of  Environmental  Protection,
John Pitch Plaza, P.O. Box 2807, Trenton,
New Jersey 08625.                       __
  (GG) [Reserved]
  (HH) New York: New York State Depart-
ment  of Environmental  Conservation,  50
Wolf Road, New York 12233, attention: Di-
vision of Air Resources.
  (II)  North Carolina  Environmental Man-
agement Commission, Department of Natu-
ral and Economic Resources, Division of En-
vironmental Management,  P.O. Box 27687,
Raleigh, North Carolina 27611. Attention:
Air Quality Section.
  (JJ) State of North Dakota, State Depart-
ment  of Health, State  Capitol,  Bismarck,
North Dakota 58501.
  (KK) Ohio-
Medina, Summit and Portage Counties; Di-
  rector, Air Pollution Control,  177 South
  Broadway, Akron, Ohio 44308.
Stark  County; Director, Air Pollution  Con-
  trol  Division, Canton City Health  Depart-
  ment,  City Hall, 218 Cleveland  Avenue
  SW., Canton, Ohio 44702.
Butler, Clermont,  Hamilton and  Warren
  Counties; Superintendent, Division of Air
  Pollution Control, 2400 Beekman Street,
  Cincinnati, Ohio 45214.
Cuyahoga  County; Commissioner, Division
  of Air Pollution Control, Department of
  Public Health and Welfare, 2735 Broad-
  way  Avenue, Cleveland, Ohio 44115.
Lorain County; Control Officer, Division of
  Air  Pollution  Control,  200 West  Erie
  Avenue, 7th Floor, Lorain, Ohio 44052.
Belmont,  Carroll,  Columbiana,  Harrison.
  Jefferson, and Monroe Counties; Director,
  North   Ohio  Valley   Air   Authority
  (NOVAA), 814 Adams Street, Steubenville,
  Ohio 43952.
Clark, Darke, Greene, Miami, Montgomery,
  and Preble Counties; Supervisor, Regional
  Air Pollution  Control Agency (RAPCA),
  Montgomery County Health Department,
  451  West  Third Street,  Dayton,  Ohio
  45402.
Lucas  County and the City of Rossford (in
  Wood County); Director, Toledo Pollution
  Control Agency, 26 Main Street,  Toledo,
  Ohio 43605.
Adams, Brown, Lawrence, and Scioto Coun-
  ties;   Engineer-Director,   Air  Division,
  Portsmouth City Health Department, 740
  Second Street, Portsmouth, Ohio 45662.
Allen,  Ashland, Auglaize, Crawford,  Defi-
  ance, Erie,  Fulton,  Hancock,   Hardin,
  Henry,  Huron,  Knox, Marion,   Mercer,
  Morrow, Ottawa, Paulding, Putnam, Rich-
  land, Sandusky,  Seneca, Van Wert, Wil-
  liams, Wood  (except  City  of Rossford),
  and Wyandot Counties; Ohio Environmen-
  tal Protection  Agency, Northwest  District
  Office,  111  West  Washington  Street,
  Bowling Green, Ohio 43402.
Ashtabula, Geauga, Lake, Mahoning, Trum-
  bull, and Wayne Counties; Ohio Environ-
  mental Protection Agency, Northeast Dis-
  trict Office,   2110  East Aurora  Road,
  Twinsburg, Ohio 44087.
Athens, Coshocton, Gallia, Guernsey, High-
  land, Hocking, Holmes, Jackson, Meigs,
  Morgan, Muskingum, Noble, Perry,  Pike,
  Ross, Tuscarawas, Vinton, and Washing-
  ton Counties; Ohio Environmental Protec-
  tion  Agency,  Southeast District  Office,
  Route 3, Box 603, Logan, Ohio 43138.
Champaign,  Clinton,  Logan,  and  Shelby
  Counties; Ohio Environmental Protection
  Agency, Southwest District Office, 7 East
  Fourth Street, Dayton, Ohio 45402.
Delaware, Fairfield, Fayette, Franklin, Lick-
  ing, Madison, Pickaway, and Union Coun-
  ties;   Ohio  Environmental  Protection
  Agency, 'Central  District Office, 369 East
  Broad Street, Columbus, Ohio  43215.
  (LL)  [Reserved]
  (MM) State of Oregon, Department of En-
vironmental  Quality,  1234 SW. Morrison
Street, Portland, Oregon 97205.
  (NN) (a) City of Philadelphia: Philadel-
phia  Department  of Public Health,  Air
Management Services,  801   Arch  Street,
Philadelphia, Pennsylvania 19107.
  (b) Commonwealth of Pennsylvania, De-
partment of Environmental Resources, Post
Office  Box 2063, Harrisburg,  Pennsylvania
17120.
  (OO) State of  Rhode Island, Department
of Environmental Management,  83  Park
Street, Providence, Rhode Island 02908.
  (PP) State of  South Carolina, Office of
Environmental   Quality  Control,  Depart-
ment of Health and Environmental Control,
2600 Bull Street, Columbia, South Carolina
29201.
                                        97

-------
 §60.5
   Title 40—Protection of Environment
  (QQ) State of South Dakota, Department
 of  Environmental  Protection,  Joe  Poss
 Building. Pierre. South Dakota 57501.
  CRR) Division  of Air  Pollution  Control.
 Tennessee  Department  of  Public Health,
 256 Capitol Hill Building. Nashville, Tennes-
 see 37219.
  (SS) State of Texas, Texas Air Control
 Board. 8520 Shoal Creek Boulevard, Austin,
 Texas 78758
  (TT) State of Utah, Utah Air Conserva-
 tion Committee,  State Division of Health,
 44  Medical Drive,  Salt Lake  City, Utah
 84113.
  (UU) State of Vermont, Agency of Envi-
 ronmental Protection, Box 489. Montpelier,
 Vermont 05602.
  (W) Commonwealth of Virginia, Virginia
 State Air Pollution Control Board, Room
 1106, Ninth Street  Office Building.  Rich-
 mond. Virginia 23219.
  (WW)  Washington:  State of Washing-
 ton,  Department  of Ecology.   Olympia,
 Washington 98504.
  (ii)  Northwest  Air Pollution Authority,
 207  Pioneer Building,  Second  and Pine
 Streets, Mount Vernon, Washington 98273.
  (iii) Puget Sound Air  Pollution  Control
 Agency, 410 West Harrison Street, Seattle,
 Washington 98119.                    .  _.
  (iv) Spokane County Air Pollution Control
 Authority,  North  811 Jefferson, Spokane,
 Washington 99201.
  (v) Southwest Air Pollution Control Au-
 thority, Suite 7601 H,  NE Hazel Dell
 Avenue, Vancouver, Washington 98665.
  (vi) Olympic Air  Pollution  Control Au-
 thority, 120 East  State  Avenue, Olympia,
 WA 98501.
  (XX) [Reserved]
  (YY) Wisconsin—Wisconsin  Department
 of Natural Resources, P.O. Box 7921, Madi-
 son. Wisconsin 53707.
  (ZZ) State of Wyoming, Air Quality Divi-
 sion of the  Department  of  Environmental
 Quality.  Hathaway  Building,  Cheyenne,
 Wyo. 82002.
  (AAA) [Reserved]
  (BBB) Commonwealth of  Puerto  Rico:
 Commonwealth  of  Puerto  Rico  Environ-
 mental Quality Board, P.O. Box 11785, San-
 turce, P.R. 00910.
  (CCC) U.S. Virgin  Islands:  U.S. Virgin Is-
 lands  Department of Conservation and Cul-
 tural  Affairs,  P.O.  Box 578,  Charlotte
 Amalie, St.  Thomas, U.S. Virgin  Islands
 00801.

 (Sees. 101, 110, 111.  112.  114, 160-169, 301.
 Clean Air Act as amended (42 U.S.C. 7401,
 7410,  7411.  7412. 7414.  7470-7479,  7491,
 7601))
 C40 PR 18169, Apr. 25. 1975,  as amended at
 40 PR 26677, June 25, 1975]

  NOTE For amendments to § 60.4  see the
List of CPR Section^ Affected appearing in
 the Finding Aids section of this volume.
 § 60.5  Determination of construction  or
    modification.
  (a) When requested to  do so by an
 owner or operator, the  Administrator
 will make a determination of whether
 action taken or intended  to be taken
 by such owner or operator constitutes
 construction  (including   reconstruc-
 tion)  or  modification  or  the  com-
 mencement thereof within  the mean-
 ing of this part.
  (b) The Administrator will respond
 to  any  request  for a  determination
 under paragraph (a) of  this  section
 within 30 days of receipt of such re-
 quest.

 [40 FR 58418, Dec. 16, 1975]

 § 60.6  Review of plans.
  (a) When requested to do so by an
 owner or operator,  the Administrator
 will review  plans for construction or
 modification for  the purpose  of  pro-
 viding technical advice to the owner or
 operator.
  (bXl)  A separate  request shall be
 submitted  for  each construction or
 modification project.
  (2) Each request  shall identify the
 location of such project, and be accom-
 panied by technical information  de-
 scribing  the  proposed  nature,  size,
 design, and method of operation of
 each affected facility involved in such
 project,  including information  on any
 equipment to  be used  for  measure-
 ment or control of emissions.
  (c)  Neither  a  request   for  plans
 review nor advice furnished by the Ad-
 ministrator  in  response  to  such  re-
 quest shall (1) relieve an owner or op-
 erator of legal  responsibility for com-
 pliance with any provision of this part
 or of any applicable State or local re-
 quirement, or (2)  prevent the Adminis-
 trator from implementing or enforcing
 any provision of  this part  or taking
 any other action authorized by  the
Act.

 [36  FR 24877, Dec.  23, 1971, as amended at
39 FR 9314, Mar. 8, 1974]

§ 60.7 Notification  and record keeping.
  (a) Any owner or operator subject to
the provisions of  this part  shall fur-
nish the Administrator written notifi-
cation as follows:
                                      98

-------
Chapter I—Environmental Protection Agency
                              §60.7
  (1) A notification of the date con-
struction (or reconstruction as defined
under § 60.15) of an affected facility is
commenced postmarked no later than
30 days after such  date. This require-
ment shall  not apply in the  case of
mass-produced facilities  which  are
purchased in completed form.
  (2) A  notification of the anticipated
date of initial startup of an affected
facility  postmarked not more than 60
days nor less than 30 days prior to
such date.
  (3) A  notification of the actual date
of initial startup of an affected facility
postmarked within  15 days after such
date.
  (4) A  notification of any physical or
operational  change to an existing fa-
cility which may increase the emission
rate of  any air pollutant to which a
standard applies, unless that change is
specifically exempted under an  appli-
cable subpart or  in  § 60.14(e).  This
notice shall be postmarked 60  days or
as  soon as practicable  before  the
change  is  commenced  and shall in~~
elude information  describing the pre-
cise nature of the change, present and
proposed  emission  control  systems,
productive   capacity  of   the  facility
before and after the  change, and  the
expected  completion date  of  the
change. The  Administrator may re-
quest additional relevant information
subsequent to this notice.
  (5) A  notification of the date upon
which demonstration of the continu-
ous  monitoring  system  performance
commences    in    accordance   with
§ 60.13(c).  Notification shall be post-
marked not less than 30 days prior to
such date.
  (b) Any owner or operator subject to
the provisions of this part shall  main-
tain records of the occurrence and du-
ration  of  any startup, shutdown,  or
malfunction in the operation of  an af-
fected facility; any malfunction of the
air pollution  control equipment;  or
any periods during which a continuous
monitoring  system  or  monitoring
device is inoperative.
  (c) Each owner or operator required
to  install  a  continuous monitoring
system  shall submit a written  report
of excess emissions (as defined in ap-
plicable subparts)  to  the Administra-
tor for every calendar  quarter.  All
quarterly reports shall be postmarked
by the 30th day following the end of
each  calendar  quarter and  shall in-
clude the following information:
  (1)  The magnitude of excess emis-
sions  computed  in  accordance  with
§ 60.13(h),  any conversion  factor(s)
used,  and the date and  time of  com-
mencement  and  completion of  each
time period of excess emissions.
  (2)  Specific  identification of  each
period of excess emissions that occurs
during startups, shutdowns,  and mal-
functions of the affected facility. The
nature and cause  of any malfunction
(if known), the corrective action taken
or preventative measures adopted.
  (3)  The date and time  identifying
each period during which the continu-
ous monitoring system was inoperative
except, for zero and span checks and
the nature of the system repairs or ad-
justments.
  (4) When  no excess emissions  have
occurred or the continuous monitoring
system(s) have not been inoperative,
repaired,  or  adjusted, such  informa-
tion shall be stated in the report.
  (d) Any owner or operator subject to
the provisions of this part shall main-
tain a file of all measurements, includ-
ing  continuous  monitoring  system,
monitoring  device, and  performance
testing measurements; all  continuous
monitoring system performance evalu-
ations;   all   continuous  monitoring
system or monitoring device calibra-
tion checks; adjustments and mainte-
nance performed on these systems or
devices; and all other  information re-
quired by this part recorded in a per-
manent form suitable for inspection.
The file  shall be retained for at least
two years following the  date of such
measurements,  maintenance,  reports,
and records.
  (e) If notification substantially simi-
lar to that in paragraph (a) of this sec-
tion is required by any other State or
local agency, sending the Administra-
tor a copy of that  notification will sat-
isfy the requirements  of paragraph (a)
of this section.

(Sec. 114, Clean  Air Act as amended (42
U.S.C. 7414))
[36 PR 24877, Dec. 28, 1971, as amended at
40 PR 46254, Oct. 6, 1975; 40 PR 58418i Dec.
                                    99

-------
§60.8
  Title 40—Protection of Environment
16. 1975; 43 PR 8800, Mar. 3, 1978; 45 PR
5617, Jan. 23,1980]

§ 60.8 Performance tests.
  (a) Within 60  days  after achieving
the  maximum   production   rate  at
which the affected facility will be  op-
erated,  but not  later than  180  days
after initial  startup  of such facility
and at such other times as may be re-
quired by the Administrator under sec-
tion 114 of the Act, the owner or oper-
ator of such facility shall conduct  per-
formance test(s)  and furnish the  Ad-
ministrator a written report of the re-
sults of such  performance test(s).
  (b) Performance tests shall be con-
ducted and data reduced in accordance
with the test methods and procedures
contained  in each applicable subpart
unless  the Administrator (1) specifies
or approves,  in specific cases, the use
of a reference   method with minor
changes  in methodology, (2) approves
the use of an equivalent method,  (3)
approves  the use of an alternative_
method the  results of which he  has"
determined to be adequate for indicat-
ing whether a  specific source is in
compliance, or (4) waives the require-
ment for  performance  tests  because
the owner or operator of a source has
demonstrated by other means to  the
Administrator's  satisfaction  that  the
affected  facility is in compliance with
the  standard. Nothing  in this para-
graph shall be construed to abrogate
the  Administrator's authority to  re-
quire testing under section 114 of the
Act.
  (c) Performance tests shall be con-
ducted under such conditions as  the
Administrator  shall  specify  to  the
plant operator based on representative
performance of the affected facility.
The owner  or  operator shall  make
available to the Administrator such re-
cords as may be necessary  to deter-
mine the conditions  of the perform-
ance tests. Operations  during periods
of startup, shutdown, and malfunction
shall not constitute  representative
conditions for the purpose of a  per-
formance test nor shall emissions in
excess of the level of the  applicable
emission limit during  periods of star-
tup, shutdown,   and malfunction be
considered a violation of the applica-
ble emission  limit  unless  otherwise
specified in the applicable standard.
  (d) The owner or operator of an af-
fected  facility  shall provide  the  Ad-
ministrator  at  least  30 days prior
notice of any performance test, except
as specified under  other subparts, to
afford the Administrator the opportu-
nity to have an observer present.
  (e) The owner or operator of an af-
fected  facility shall provide, or cause
to be  provided, performance  testing
facilities as follows:
  (1) Sampling ports adequate for test
methods applicable to such facility.
  (2) Safe sampling platform(s).
  (3)   Safe   access   to   sampling
platform(s).
  (4) Utilities for sampling and testing
equipment.
  (f) Unless otherwise  specified in the
applicable subpart, each performance
test  shall consist  of  three separate
runs using the applicable test method.
Each run shall be  conducted for the
time and under the conditions speci-
fied  in  the applicable standard.  For
the purpose of determining compli-
ance with an applicable  standard, the
arithmetic means  of  results  of  the
three runs shall apply.  In  the event
that a sample is accidentally lost or
conditions occur in which one of the
three runs must be discontinued be-
cause of  forced shutdown,  failure of
an irreplaceable portion of the sample
train, extreme meteorological  condi-
tions, or other circumstances,  beyond
the owner or operator's  control, com-
pliance may, upon the Administrator's
approval, be  determined  using  the
arithmetic mean of the results of the
two other runs.

(Sec. 114,  Clean Air  Act as amended (42
U.S.C. 7414))
[36 PR  24877, Dec. 23, 1971, as  amended at
39 PR 9314. Mar. 8, 1974;  42 PR 57126, Nov.
1, 1977; 43 PR  8800,  Mar.  3, 1978; 44 PR
33612, June 11, 1979]

§ 60.9  Availability of information.
  The availability  to the public of in-
formation provided to,  or  otherwise
obtained by, the Administrator under
this Part shall be  governed by Part 2
of this chapter. (Information submit-
ted voluntarily  to  the Administrator
for the purposes of § § 60.5  and 60.6 is
                                   100

-------
Chapter I—Environmental Protection Agency
                              §60.11
governed by § 2.201 through § 2.213 of
this chapter and not by § 2.301 of this
chapter.)
(Sec.  114, Clean Air Act as amended (42
U.S.C. 7414))
[41 PR 36918, Sept. 1, 1976, as  amended at
43 PR 8800, Mar. 3, 1978]

§ 60.10  State authority.
  The provisions of this part shall not
be construed  in any manner to  pre-
clude any State or political subdivision
thereof from:
  (a)  Adopting and  enforcing  any
emission standard or limitation appli-
cable to an affected facility, provided
that such emission standard or limita-
tion  is  not  less stringent1 than the
standard applicable to such facility.
  (b) Requiring the owner or operator
of an affected facility to obtain per-
mits, licenses, or approvals prior to ini-
tiating  construction,  modification, or
operation of such facility.
(Sec. 116, Clean Air  Act as amended (42-.
U.S.C. 7416))
[36 PR 24877, Dec. 23, 1971,  as amended at
43 PR 8800, Mar. 3, 1978]

§60.11   Compliance with  standards and
   maintenance requirements.
  (a)  Compliance  with  standards in
this  part,  other than opacity  stand-
ards, shall be determined only by per-
formance tests  established  by § 60.8,
unless otherwise specified in the appli-
cable standard.
  (b) Compliance with opacity stand-
ards in this  part sho.ll be determined
by conducting observations  in accord-
ance with  Reference Method 9 in Ap-
pendix  A of this part or any alterna-
tive  method that is  approved by the
Administrator.  Opacity  readings of
portions of plumes which contain con-
densed, uncombined water vapor shall
not be  used for purposes of determin-
ing compliance with opacity standards.
The results of continuous  monitoring
by   transmissonieter  which indicate
 that the opacity at the time visual ob-
 servations  were  made   was  not  in
 excess  of  the standard  are probative
 but  not  conclusive  evidence  of the
 actual opacity of an emission, provided
 that the source shall meet  the burden
 of proving that the instrument used
 meets (at the time of the alleged viola-
tion)  Performance Specification 1 in
Appendix B of this part, has  been
properly maintained and (at the time
of the  alleged  violation) calibrated,
and that the resulting  data  have not
been tampered with in any way.
  (c) The opacity  standards  set forth
in this  part shall  apply at  all times
except during periods of startup, shut-
down, malfunction, and  as otherwise
provided in the applicable standard.
  (d) At all times,  including periods of
startup, shutdown, and  malfunction,
owners  and operators   shall,  to  the
extent practicable, maintain and oper-
ate any affected facility including as-
sociated air pollution  control equip-
ment in  a manner consistent with
good air pollution control practice for
minimizing  emissions.  Determination
of whether acceptable  operating and
maintenance  procedures are being
use'd  will  be based on  information
available to the Administrator which
may  include, but is not limited to,
monitoring  results,  opacity  observa-
tions, review of operating and mainte-
nance  procedures, and inspection  of
the source.
  (eXl) An owner  or operator of an af-
fected facility may request the Admin-
istrator to determine opacity of emis-
sions from the affected facility during
the initial performance tests required
by § 60.8.
  (2) Upon receipt from such owner or
operator of the written report of the
results  of the  performance  tests re-
quired by §  60.8, the Administrator will
make a finding  concerning compliance
with  opacity   and  other applicable
standards. If the  Administrator finds
that  an affected  facility is in compli-
ance with all applicable standards for
which  performance tests are conduct-
ed in  accordance with § 60.8 of this
part  but during  the  time  such per-
formance  tests are  being conducted
fails  to meet  any applicable opacity
standard, he shall notify the owner or
operator and advise  him that he may
petition the Administrator  within  10
days of receipt  of notification to make
appropriate adjustment to the opacity
standard for the affected facility.
   (3) The  Administrator will  grant
such a petition upon a demonstration
 by the owner or operator that the  af-
 fected  facility and associated air pollu-
                                     101

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 § 60.12
   Title 40—Protection of Environment
tion control equipment was operated
and maintained in a manner to mini-
mize the opacity  of  emissions  during
the performance  tests;  that the per-
formance tests were  performed under
the conditions established by the Ad-
ministrator; and that the affected fa-
cility and associated air pollution con-
trol  equipment  were   incapable of
being adjusted or operated to meet the
applicable opacity standard.
  (4) The Administrator will establish
an opacity standard  for the  affected
facility  meeting  the above  require-
ments at a level at which the  source
will be able, as indicated by the per-
formance and opacity  tests,  to meet
the opacity  standard   at  all  times
during  which the source  is  meeting
the mass  or concentration emission
standard. The Administrator will pro-
mulgate the new  opacity standard in
the FEDERAL REGISTER.
(Sec. 114, Clean Air Act  as amended (42
0.S.C. 7414))
t38 PR 28565, Oct. 15, 1973, as amended at"""
39 PR 39873, Nov. 12. 1974; 42 FR 26206,
May 23, 1977; 43 FR 8800. Mar. 3, 1978: 45
FR 23379, Apr. 4. 1980]

§ 60.12  Circumvention.
  No owner or operator subject to the
provisions of this part shall  build,
erect, install,  or use any article, ma-
chine, equipment or process, the use of
which  conceals  an  emission  which
would otherwise constitute a violation
of an applicable standard.  Such con-
cealment includes, but  is not  limited
to, the  use  of gaseous diluents to
achieve  compliance with an opacity
standard or with a standard which is
based on the concentration of a pollut-
ant in the gases discharged to the at-
mosphere.
£39 FR 9314. Mar. 8. 1974]

§ 60.13  Monitoring requirements.
  (a) For the purposes of this section,
all continuous monitoring systems re-
quired under applicable subparts shall
be subject to the provisions of this sec-
tion upon promulgation of perform-
ance  specifications  for  continuous
monitoring system under Appendix B
to this part, unless:
  (1)   The  continuous  monitoring
system is subject to the provisions of
paragraphs (c)(2) and (c)(3) of  this
section, or
  (2) otherwise specified in an applica-
ble subpart or by the Administrator.
  (b)  All continuous monitoring  sys-
tems  and monitoring devices shall be
installed and operational prior to con-
ducting   performance   tests   under
§ 60.8.  Verification   of   operational
status shall, as a minimum, consist of
the following:
  (1)  For continuous monitoring  sys-
tems referenced in paragraph (c)(l) of
this section, completion of the  condi-
tioning period specified by applicable
requirements in Appendix B.
  (2)  For continuous monitoring  sys-
tems referenced in paragraph (c)(2) of
this section, completion of seven days
of operation.
  (3)  For  monitoring  devices  refer-
enced  in applicable  subparts, comple-
tion of the manufacturer's written re-
quirements  or recommendations  for
checking the operation or calibration
of the device.
  (c) During any performance tests re-
quired under § 60.8  or within 30 days
thereafter and at such other times as
may be required by the Administrator
under section  114  of the  Act,  the
owner or operator of any affected fa-
cility  shall conduct  continuous  moni-
toring system performance evaluations
and furnish the Administrator within
60 days thereof two or, upon request,
more  copies of a written report of the
results of such tests. These continuous
monitoring system performance  evalu-
ations shall be  conducted in accord-
ance with the following specifications
and procedures:
  (1)  Continuous monitoring systems
listed within this paragraph except as
provided in paragraph (c)(2) of this
section shall be  evaluated in accord-
ance with the requirements and proce-
dures contained in the applicable per-
formance specification of  Appendix B
as follows:
  (i) Continuous monitoring  systems
for measuring opacity of  emissions
shall comply with Performance Speci-
fication 1.
  (ii)  Continuous monitoring systems
for measuring  nitrogen oxides emis-
sions  shall comply  with Performance
Specification 2.
                                   102

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Chapter I—Environmental Protection Agency
                             § 60.13
  (iii) Continuous monitoring systems
for measuring sulfur dioxide emissions
shall comply with Performance Speci-
fication 2.
  (iv) Continuous monitoring systems
for measuring the oxygen content or
carbon  dioxide  content  of  effluent
gases shall comply  with Performance
Specification 3.
  (2) An owner or operator who, prior
to September 11, 1974, entered into a
binding contractual obligation to pur-
chase specific continuous monitoring
system  components except as  refer-
enced by paragraph (c)(2)(iii) of this
section  shall comply with the follow-
ing requirements:
  (i)  Continuous monitoring systems
for measuring  opacity  of  emissions
shall be capable  of measuring emission
levels within ±20 percent with a confi-
dence level of 95 percent. The Calibra-
tion Error Test and associated calcula-
tion  procedures  set forth in Perform-
ance  Specification  1 of Appendix B
shall  be used for demonstrating com-
pliance with this specification.
  (ii)  Continuous monitoring systems
for measurement of nitrogen oxides or
sulfur dioxide  shall be capable  of
measuring  emission levels within ±20
percent with a confidence level of 95
percent. The Calibration Error Test,
the Field Test for Accuracy (Relative),
and associated operating and  calcula-
tion  procedures  set forth in Perform-
ance  Specification  2 of Appendix B
shall  be used for demonstrating com-
pliance with this specification.
  (iii) Owners or operators of all con-
tinuous monitoring  systems  installed
on an affected facility prior to October
6, 1975 are not required to conduct
tests under paragraphs (c)(2)(i) and/or
(ii) of this  section unless requested by
the Administrator.
  (3)  All continuous monitoring  sys-
tems referenced  by paragraph (c)(2) of
this  section shall be upgraded  or re-
placed  (if  necessary) with  new con-
tinuous monitoring  systems, and  the
new or improved systems shall be dem-
onstrated to comply with applicable
performance   specifications    under
paragraph  (c)(l) of this section on or
before September 11, 1979.
  (d)  Owners or operators of  all con-
tinuous monitoring  systems  installed
in accordance with  the provisions of
this part shall check the zero and span
drift at least once daily in accordance
with  the method prescribed  by  the
manufacturer of  such systems unless
the manufacturer recommends adjust-
ments at shorter intervals, in which
case such  recommendations shall  be
followed. The zero and span shall, as a
minimum,  be adjusted whenever  the
24-hour zero drift or 24-hour calibra-
tion drift limits of the applicable per-
formance specifications in Appendix B
are exceeded. For continuous monitor-
ing systems measuring opacity of emis-
sions, the optical surfaces exposed to
the effluent gases shall be  cleaned
prior  to performing the  zero  or span
drift adjustments except that for sys-
tems  using  automatic  zero  adjust-
ments,  the optical surfaces shall  be
cleaned when the cumulative automat-
ic zero compensation exceeds four per-
cent  opacity.  Unless otherwise  ap-
proved  by  the Administrator,  the  fol-
lowing procedures, as applicable, shall
be followed:
  (1) For extractive continuous moni-
toring systems measuring gases, mini-
mum  procedures shall include  intro-
ducing  applicable zero and span  gas
mixtures   into   the  measurement
system  as near the probe as is practi-
cal. Span and zero gases certified  by
their  manufacturer to be traceable to
National Bureau of Standards  refer-
ence  gases shall be  used whenever
these  reference  gases are available.
The span and zero gas mixtures shall
be the  same composition as specified
in Appendix B of this part. Every six
months  from  date of manufacture,
span  and zero gases shall be reana-
lyzed  by conducting triplicate analyses
with Reference Methods  6  for SO2, 7
for NO,, and 3 for Oa and CO,, respec-
tively. The gases may be analyzed at
less frequent intervals if  longer shelf
lives are guaranteed by the manufac-
turer.
  (2)  For  non-extractive  continuous
monitoring systems measuring gases,
minimum  procedures shall  include
upscale check(s) using a certified cali-
bration gas cell  or test cell which  is
functionally equivalent to a known gas
concentration. The zero check may be
performed  by computing  the  zero
value from upscale measurements or
                                    103

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  §60.13

  by mechanically producing a zero con-
  dition.
   (3)  For continuous monitoring sys-
  tems  measuring opacity of emissions,
  minimum procedures shall include a
  method for producing a simulated zero
  opacity  condition   and  an  upscale
  (span) opacity condition using a certi-
  fied neutral density filter or other  re-
  lated  technique to produce  a  known
  obscuration of the light beam. Such
  procedures  shall  provide  a system
  check of the analyzer internal optical
 surfaces and all electronic circuitry  in-
 cluding the lamp and  photodetector
 assembly.
   (e) Except  for  system breakdowns,
 repairs, calibration checks, and  zero
 and span adjustments required under
 paragraph (d) of  this section, all con-
 tinuous monitoring systems shall be in
 continuous operation and shall meet
 minimum  frequency of operation re-
 quirements as follows:
   (1)  All continuous monitoring sys-
 tems referenced by paragraphs (cXl)
 and (c)(2) of  this section for measur-—
 ing opacity of emissions shall complete
 a minimum of one  cycle of sampling
 and analyzing for each successive ten-
 second period and one cycle of data re-
 cording for each successive six-minute
 period.
  (2)  All  continuous monitoring  sys-
 tems referenced by paragraph (c)(l)  of
 this section for measuring oxides of ni-
 trogen, sulfur dioxide, carbon dioxide,
 or oxygen shall complete a minimum
 of  one cycle of operation (sampling,
 analyzing,  and data recording)  for
 each successive 15-minute period.
  (3) All  continuous monitoring sys-
 tems referenced by paragraph (c)(2) of
 this section, except opacity, shall com-
 plete a minimum of  one  cycle of oper-
 ation  (sampling,  analyzing, and  data
 recording)  for each successive  one-
 hour period.
  (f) All continuous monitoring sys-
 tems or monitoring devices shall be in-
stalled such that representative meas-
urements  of emissions or process pa-
rameters from the affected facility are
obtained. Additional  procedures for lo-
cation  of  continuous monitoring sys-
tems contained in  the applicable Per-
formance  Specifications  of  Appendix
B of this part shall be used.
    Title 40—Protection of Environment

   (g) When the effluents from a single
 affected facility or two or more affect-
 ed facilities subject to the same emis-
 sion standards  are  combined  before
 being released to the atmosphere, the
 owner or operator may install applica-
 ble continuous monitoring systems on
 each effluent or on the combined ef-
 fluent. When the affected facilities are
 not  subject to  the same  emission
 standards,  separate continuous  moni-
 toring systems shall  be  installed on
 each effluent. When the effluent from
 one  affected facility is released to the
 atmosphere through  more than  one
 point, the owner or operator shall in-
 stall applicable continuous monitoring
 systems  on  each  separate  effluent
 unless  the installation  of fewer sys-
 tems is approved by  the Administra-
 tor.
   (h) Owners or operators of all con-
 tinuous monitoring systems for mea-
 surement  of opacity shall reduce all
 data to six-minute  averages and  for
 systems other  than opacity to  one-
 hour averages for time periods under
 § 60.2 (x) and (r)  respectively.  Six-
 minute opacity averages  shall be cal-
 culated from 24 or more data  points
 equally spaced over each  six-minute
 period. For systems other than  opac-
 ity,  one-hour averages shall be com-
 puted from four or more data  points
 equally spaced  over  each  one-hour
 period. Data recorded during periods
 of system breakdowns, repairs, calibra-
 tion checks, and zero and span adjust-
 ments shall not  be  included  in the
 data  averages computed  under  this
 paragraph. An arithmetic or integrat-
 ed average of  all data may be used.
 The  data  output  of  all  continuous
 monitoring systems  may  be recorded
 in reduced  or  nonreduced  form (e.g.
 ppm  pollutant and percent O, or lb/
 million Btu  of pollutant).  All excess
 emissions shall be converted into units
 of the standard  using the  applicable
 conversion procedures specified in sub-
 parts. After  conversion into units of
 the standard, the  data may be round-
 ed to the  same number of significant
 digits used in subparts to specify the
 applicable  standard  (e.g., rounded to
 the nearest one percent opacity).
  (i) After receipt and consideration of
written application, the Administrator
may approve alternatives to any moni-
                                   104

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Chapter I—Environmental Protection Agency

taring  procedures or requirements of
this part including, but not limited to
the following:
  (1) Alternative monitoring  require-
ments  when installation of a continu-
ous monitoring system or monitoring
device  specified by this part would not
provide accurate measurements due to
liquid  water  or other  interferences
caused by substances with the effluent
                             § 60.14
gases.
  (2) Alternative monitoring  require-
ments when the affected facility is in-
frequently operated.
  (3) Alternative monitoring  require-
ments   to accommodate  continuous
monitoring systems that require addi-
tional  measurements  to correct   for
stack moisture conditions.
  (4) Alternative locations for install-
ing continuous monitoring systems or
monitoring devices when the owner or
operator can demonstrate that instal-
lation   at  alternate  locations  will
enable  accurate and  representative
measurements.
  (5) Alternative methods  of  convert""
ing  pollutant  concentration  meas-
urements to units of the standards.
  (6) Alternative procedures  for  per-
forming daily checks of zero and span
drift that do  not involve use of span
gases or test cells.
  (7) Alternatives, to the A.S.T.M. test
methods or sampling procedures speci-
fied by any subpart.
  (8) Alternative continuous monitor-
ing  systems  that  do not meet   the
design or performance requirements in
Performance  Specification  1,  Appen-
dix B, but adequately demonstrate a
definite  and  consistent relationship
between  its  measurements and   the
measurements of opacity by a system
complying with the requirements in
Performance  Specification  1.  The Ad-
ministrator may require  that  such
demonstration be performed  for  each
affected facility.
  (9) Alternative monitoring  require-
ments when the effluent from a single
 affected facility or the combined efflu-
 ent from two or more affected facili-
 ties are  released to  the  atmosphere
 through more than one point.
 (Sec.  114, Clean  Air Act as amended (42
 U.S.C. 7414))
 [40 PR 46255,  Oct. 6,  1975; 40 FR 59205,
 Dec. 22, 1975, as  amended  at 41 PR 35185,
Aug. 20, 1976; 42 FR 5936, Jan. 31, 1977; 43
FR 7572, Feb. 23, 1978; 43 FR 8800, Mar. 3,
1978]

§ 60.14  Modification.
  (a) Except as  provided under para-
graphs (e) and (f) of this section, any
physical  or operational change to an
existing facility which results in an in-
crease in the  emission rate to the at-
mosphere of any pollutant to which a
standard applies shall be considered a
modification within  the meaning of
section 111 of the Act. Upon modifica-
tion, an  existing facility shall become
an affected facility for each pollutant
to which a standard  applies and for
which there is an increase in the emis-
sion rate to the atmosphere.
  (b) Emission rate shall be expressed
as kg/hr of any pollutant discharged
into  the  atmosphere for  which  a
standard is applicable. The Adminis-
trator shall use the following to deter-
mine emission rate:
  (1)  Emission factors as specified  in
the latest issue of "Compilation of Air
Pollutant  Emission  Factors,"  EPA
Publication No. AP-42, or other emis-
sion factors determined by the Admin-
istrator to be superior to AP-42 emis-
sion factors, in cases where utilization
of emission factors demonstrate that
the emission  level resulting from the
physical  or operational change will
either clearly increase or clearly not
increase.
   (2)  Material  balances,  continuous
monitor data, or manual emission tests
in cases where utilization of emission
factors as referenced in paragraph (b)
(1) of this section does not demon-
strate to the Administrator's  satisfac-
tion whether the emission level result-
ing from  the physical or operational
change will either clearly increase or
clearly  not  increase,  or where  an
 owner or operator demonstrates to the
 Administrator's satisfaction that there
 are reasonable grounds  to dispute the
 result obtained by  the  Administrator
 utilizing emission factors as referenced
 in paragraph (bXl)  of this section.
 When the emission rate is based on re-
 sults  from manual  emission  tests or
 continuous monitoring  systems,  the
 procedures specified in Appendix C of
 this  part shall be used to determine
 whether an increase in  emission rate
                                     105

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 § 60.15
   Title 40—Protection of Environment
 has occurred. Tests shall be conducted
 under such conditions as the Adminis-
 trator shall specify to the owner or op-
 erator  based  on  representative  per-
 formance of the facility. At least three
 valid  test  runs must  be conducted
 before  and  at least three  after  the
 physical or operational change. All op-
 erating parameters which may affect
 emissions must be held constant to the
 maximum feasible degree for all test
 runs.
  (c) The addition of an affected facili-
 ty to a stationary source as an expan-
 sion to that source or as a replacement
 for  an existing facility  shall not by
 itself bring within  the  applicability of
 this part any other facility within that
 source.
  (d) [Reserved]
  (e) The following shall not, by them-
 selves,  be  considered  modifications
 under this part:
  (1) Maintenance,  repair, and replace-
 ment which the Administrator deter-
 mines to be routine for a source cate-
 gory, subject to the provisions of para-
 graph (c) of this section and § 60.15.
  (2) An increase in production rate of
 an  existing  facility,  if  that  increase
 can be accomplished without a capital
 expenditure on that facility.
  (3) An increase in the hours of oper-
 ation.
  (4) Use of an alternative fuel  or raw
 material  if,  prior  to  the date  any
 standard under this part becomes ap-
 plicable to  that source type,  as  pro-
 vided by  §60.1,  the existing facility
 was designed to accommodate that al-
 ternative use. A facility shaU be  con-
 sidered to be designed to accommodate
 an alternative  fuel or raw material if
 that use could be accomplished under
 the  facility's  construction  specifica-
 tions as amended prior to the change.
 Conversion to coal required for energy
 considerations, as specified in section
 lll(a)(8) of the Act, shall not be con-
sidered a modification.
  (5)  The addition  or  use  of  any
system or device whose primary func-
tion  is the reduction of air pollutants,
except  when  an  emission  control
system is removed  or is replaced by a
system which the Administrator deter-
mines to be less environmentally bene-
ficial.
   (6) The relocation or change in own-
 ership of an existing facility.
   (f) Special provisions set forth under
 an applicable subpart of this part shall
 supersede any conflicting provisions of
 this section.
   (g) Within  180  days  of  the comple-
 tion  of any  physical  or  operational
 change subject to the control  meas-
 ures  specified in paragraph (a) of this
 section, compliance with all applicable
 standards must be achieved.

 C40 FR 58419, Deo. 16, 1975, amended at 43
 FR 34347, Aug. 3, 1978; 45 FR 5617, Jan. 23.
 1980]

 § 60.15  Reconstruction.
   (a) An existing  facility, upon recon-
 struction, becomes an affected facility,
 irrespective of any change in emission
 rate.
   (b) "Reconstruction" means the re-
 placement of  components  of  an exist-
 ing facility to  such an extent that:
   (1)  The fixed capital cost of the new
 components exceeds 50 percent of the
 fixed capital  cost that would be  re-
 quired  to construct a comparable  en-
 tirely new facility, and
   (2)  It is technologically and  economi-
 cally  feasible  to meet  the applicable
 standards set forth in this part.
  (c)  "Fixed capital cost" means the
 capital  needed to provide all the  de-
 preciable components.
  (d)  If an owner or operator  of an ex-
 isting facility  proposes to replace com-
 ponents, and  the fixed capital cost  of
 the new components exceeds 50 per-
 cent  of the  fixed capital cost that
 would be required to construct a com-
 parable entirely new facility,  he shall
 notify the Administrator of  the pro-
 posed replacements. The notice must
 be postmarked 60 days (or as soon  as
 practicable) before construction of the
 replacements  is  commenced and must
 include the following information:
  (1)  Name and address of the owner
or operator.
  (2)  The location of the existing  fa-
cility.
  (3)  A  brief description of the exist-
ing facility and the components which
are to be replaced.
  (4) A  description of the existing air
pollution control  equipment  and the
                                    106

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Chapter I—Environmental Protection Agency
                               § 60.16
proposed air pollution control equip-
ment.
  (5) An estimate of the fixed capital
cost of the replacements and of con-
structing a  comparable entirely new
facility.
  (6) The estimated life of the existing
facility after the replacements.
  (7) A discussion of any economic or
technical limitations the facility may
have in complying with the applicable
standards  of  performance after  the
proposed replacements.
  (e)  The  Administrator  will  deter-
mine, within 30 days of the receipt of
the notice required by paragraph (d)
of this section and any additional in-
formation he may reasonably require,
whether  the proposed  replacement
constitutes reconstruction.
  (f) The  Administrator's determina-
tion under  paragraph  (e)   shall  be
based on:
  (1) The fixed capital cost of the re-
placements in comparison to  the fixed
capital cost  that would be required to
construct  a comparable entirely new--
facility;
  (2) The estimated life of the facility
after the  replacements compared to
the life  of a comparable entirely new
facility;
  (3) The extent to which the compo-
nents being replaced cause or contrib-
ute to the emissions from the facility;
and
  (4) Any economic or  technical limita-
tions on compliance  with applicable
standards of  performance which are
inherent  in  the  proposed   replace-
ments.
  (g) Individual subparts of  this part
may include specific provisions  which
refine and delimit  the concept  ,of  re-
construction set forth  in this  section.
[40 PR 58420, Dec. 16, 1975]

§ 60.16  Priority list.
   PRIORITIZED MAJOR SOURCE CATEGORIES
            Priority Number'
             Source Category
 1. Synthetic Organic Chemical Manufactur-
    ing
  (a) Unit processes
  • Low numbers have highest priority; e.g.,
 No. 1 is high priority, No. 59 is low priority.
  (b) Storage and handling equipment
  (c) Fugitive emission sources
  (d) Secondary sources
2. Industrial Surface Coating: Cans
3. Petroleum Refineries: Fugitive Sources
4. Industrial Surface Coating: Paper
5. Dry Cleaning
  (a) Perchioroethylene
  (b) Petroleum solvent
6. Graphic Arts
7. Polymers and Resins: Acrylic Resins
8. Mineral Wool
9. Stationary Internal Combustion Engines
10. Industrial Surface Coating: Fabric
11. Fossil-Fuel-Fired  Steam Generators: In-
   dustrial Boilers
12. Incineration: Non-Municipal
13. Non-Metallic Mineral Processing
14. Metallic Mineral Processing
15. Secondary Copper
16. Phosphate Rock Preparation
17. Foundries: Steel and Gray Iron
18. Polymers and Resins: Polyethylene
19. Charcoal Production
20. Synthetic Rubber
  (a) Tire manufacture
  (b) SBR production
21. Vegetable Oil
22. Industrial Surface Coating: Metal Coil
23.  Petroleum Transportation and Market-
    ing
24. By-Product Coke Ovens
25. Synthetic Fibers
26. Plywood Manufacture
27. Industrial Surface Coating: Automobiles
28. Industrial Surface Coating: Large Appli-
    ances
29. Crude Oil and Natural Gas Production
30. Secondary Aluminum
31. Potash
32. Sintering: Clay and Fly Ash
33. Glass
34. Gypsum
35. Sodium Carbonate
36. Secondary Zinc
37. Polymers and Resins: Phenolic
38. Polymers and Resins: Urea—Melamine
39. Ammonia
40. Polymers and Resins: Polystyrene
41. Polymers and Resins: ABS-SAN Resins
42. Fiberglass
43.  Polymers and Resins: Polypropylene
44.  Textile Processing
45.  Asphalt Roofing Plants
46.  Brick and Related Clay Products
47.  Ceramic Clay Manufacturing
48.  Ammonium Nitrate Fertilizer
49.  Castable Refractories
50.  Borax and Boric Acid
51.  Polymers and Resins: Polyester Resins
52.  Ammonium Sulfate
53.  Starch
54.  Perlite
55.  Phosphoric Acid: Thermal Process
56.  Uranium Refining
57.  Animal Feed Defluorination
                                      107

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§60.20
Titla 40—Protection of Environment
                       58. Urea (for fertilizer and polymers)
                       59. Detergent

                               OTHER SOURCE CATEGORIES

                       Lead acid battery manufacture"
                       Organic solvent cleaning"
                       Industrial surface coating: metal furniture"
                       Stationary gas turbines*"
                        "Minor source category, but  included on
                       list since an NSPS is being developed for that
                       source category.
                        "•Not prioritized, since an NSPS for this
                       major source category has already been pro-
                       posed.

                       C44 PR 49225, Aug. 21, 1979]
                                      108

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          APPENDIX B

EPA METHODS 1, 2, 3, AND 7 AND
  PERFORMANCE SPECIFICATION 2
              109

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Chapter I—Environmental Protection Agency
App. A
                     METHOD 1.—SAMPLE AND VELOCITY TRAVERSES
                              FOR STATIONARY SOURCES
                     1. Principle and Applicability
                       1.1  Principle. To aid in  the representa-
                     tive  measurement of  pollutant emissions
                     and/or total volumetric flow  rate from a
                     stationary source, a measurement site where
                     the effluent stream is flowing in a known di-
                     rection is selected, and the cross-section of
                     the stack is divided into a number of equal
                     areas.  A traverse point  is  then located
                     within each of these equal areas.
                      1.2  Applicability. This method is applica-
                     ble to flowing gas streams in ducts, stacks,
                     and  flues.  The method cannot  be  used
                     when: (1) flow  is  cyclonic or swirling (see
                     Section  2.4), (2) a stack  is  smaller than
                     about 0.30 meter  (12 in.)  in diameter,  or
                     0.071 m2(113 in.2) cross-sectional area, or (3)
                     the measurement site is less than two stack
                     or duct diameters downstream or less than a
                     half diameter upstream from a flow disturb-
                     ance.
                      The requirements of this method must  be
                     considered before construction of a new fa-
                     cility from which  emissions will be meas-
                     ured; failure to do so  may require subse-
                     quent alterations to the stack  or deviation
                     from  the standard procedure.  Cases involv-
                     ing variants are subject to approval by the
                     Administrator, U.S. Environmental Protec-
                     tion Agency.
                     2. Procedure
                      2.1  Selection of  Measurement Site. Sam-
                    pling  or velocity measurement is performed
                    at a site located  at least eight stack or duct
                    diameters downstream  and  two diameters
                    upstream from any flow disturbance such as
                    a bend, expansion, or  contraction in the
                    stack, or from a visible flame.  If necessary,
                    an alternative location may be selected, at a
                    position at least two stack or duct diameters
                    downstream  and a  half diameter upstream
                    from any flow disturbance. For a rectangu-
                    lar  cross section,  an  equivalent diameter
                    (A), shall be calculated  from the following
                    equation, to determine  the  upstream and
                    downstream distances:
                                       2LW
                                     ''(L+W)
                   where i=length and W=width.
                     2.2  Determining the Number of Traverse
                   Points.
                                      110

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App. A
Title 40—Protection of Environment
             SINIOd BSU3AVU1
                               111

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 Chapter I—Environmental Protection Agency
                                App. A
  2.2.1 Particulate  Traverses.  When  the
eight-  and two-diameter criterion can  be
met,  the minimum  number  of  traverse
points shall be:  (1) twelve, for circular or
rectangular stacks with diameters (or equiv-
alent diameters) greater than 0.61 meter (24
in.); (2) eight, for circular stacks with diam-
eters  between 0.30  and 0.61  meter (12-24
in.); (3) nine,  for rectangular stacks with
equivalent diameters between 0.30 and 0.61
meter (12-24 in.).
  When the eight- and two-diameter crite-
rion cannot be met, the minimum number
of traverse points is determined from Figure
1-1. Before referring to the figure, however,
determine the distances  from the chosen
measurement site to the  nearest upstream
and  downstream disturbances,  and divide
each  distance  by the stack diameter  or
equivalent diameter,  to determine  the dis-
tance in terms of the number of duct diame-
ters. Then, determine from Figure 1-1 the
minimum number of  traverse points that
corresponds: (1) to the number of  duct di—
ameters upstream; and (2) to the number of
diameters downstream. Select the higher of
the  two minimum  numbers  of traverse
points, or a greater value, so that for circu-
lar stacks the number is a multiple of 4, and
for rectangular stacks, the number is one of
those shown in Table 1-1.


  TABLE 1-1. CROSS-SECTION LAYOUT FOR
          RECTANGULAR STACKS
Number of traverse points
9 	
12 	
16 	
20 	
25 	
30
36 	
42 	
49 	

Matrix layout
3x3
4x3
4x4
5x4
5x5
6x5
6x6
7x6
7x7

                                       112

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App. A
Title 40—Protection of Environment
                      3S«3Avai do aaawnN
                                                                   ro
                                                                   a
                                                                   c
                                                                   o
                                                                   c
                                                                   C

                                                                   '5
                                                                   a

                                                                   QJ
                                                                   o

                                                                   02


                                                                   E
                                                                   3
                                                                   C

                                                                   E
                                                                   3

                                                                   E

                                                                   c
                                                                    O)
                                113

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Chapter I—Environmental Protection Agency
                                  APP. A
  2.2.2  Velocity   (Non-Paniculate)   Tra-
verses.  When velocity  or volumetric flow
rate is to be determined (but not paniculate
matter), the same procedure as that for par-
ticulate traverses (Section 2.2.1) is followed,
except that Figure  1-2 may be used instead
of Figure 1-1.
  2.3  Cross-sectional Layout and Location
of Traverse Points.
  2.3.1  Circular Stacks. Locate the traverse
points on two perpendicular diameters ac-
cording to Table 1-2 and the example shown
in Figure 1-3. Any  equation (for examples,
see  Citations 2 and 3 in  the Bibliography)
that gives the same values as those in Table
1-2  may be used in lieu of Table 1-2.
  For paniculate traverses, one of the diam-
eters  must  be in a  plane containing the
greatest expected concentration variation,
e.g., after bends, one diameter shall be  in
the plane of the bend. This requirement be-
comes less  critical as the  distance from the
disturbance increases; therefore,  other di-
ameter locations may be used, subject to ap-
proval of the Administrator.
  In addition for stacks having diameters
greater than 0.61  m  (24 in.) no  traverse
points shall be  located within 2.5 centi-
meters (1.00 in.) of the stack walls; and for
stack diameters equal to or less than 0.61 m
(24 in.), no  traverse points shall be located
within 1.3 cm (0.50 in.) of the stack walls.
To meet these criteria, observe  the proce-
dures given  below.
  2.3.1.1  Stacks  With  Diameters  Greater
Than 0.61 m (24  in.). When  any  of the tra-
verse points as located in Section  2.3.1 fall
within 2.5 cm (1.00 in.) of the stack  walls, re-
locate them away from the  stack  walls to:
(1) a distance of 2.5 cm  (1.00 in.); or (2) a
distance equal to  the nozzle inside diameter,
whichever  is larger. These   relocated  tra-
verse points (on each  end  of a diameter)
shall be the "adjusted" traverse points.
  Whenever two  successive  traverse points
are combined to form a single adjusted tra-
verse point, treat the adjusted point as two
separate traverse points, both in the sam-
pling (or velocity measurement)  procedure,
and in recording the data.
    TRAVERSE       DISTANCE.
     POINT       % of diameter

        1              4.4
        2             14.7
        3             29.5
        4             70.5
        5             85.3
        6             95.6
                Figure 1-3.  Example showing circular stack cross section divided into
                12 equal areas, with location of traverse points indicated.
              TABLE 1-2. LOCATION OF TRAVERSE POINTS IN CIRCULAR STACKS
                      [Percent of stack diameter from inside wall to traverse point]
Traverse point number on a diameter
1«.
2
3... ..
4 	 	

6 „.„....„ 	 „
7 	 „ 	

2
14.6
85.4
	


Number of traverse points on a diameter—
4
6.7
25.0
75.0
93.3


6
4.4
14.6
29.6
70.4
85.4
95.6
8
3.2
10.5
19.4
32.3
67.7
80.6
89.5
10
2.6
8.2
14.6
22.6
34.2
65.8
77.4
12
2.1
6.7
11.8
17.7
25.0
35.6
64.4
14
1.8
' 5.7
9.9
14.6
20.1
26.9
36.6
16
1.6
4.9
8.5
12.5
16.9
22,0
28.3
18
1.4
4.4
7.5
10.9
14.6
18.8
23.6
20
1.3
3.9
6.7
9.7
12.9
16.5
2O.4
22
1.1
3.5
6.0
8.7
11.6
14.6
18.0
24
1.1
3.2
5.5
7.9
10.5
13.2
16.1
                                         114

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 APP.A
   Title 40—Protection of Environment
         TABLE 1-2. LOCATION OF TRAVERSE POINTS IN CIRCULAR STACKS—Continued
                       [Percent of stack diameter from inside wall to traverse point]
Traverse point number on a diameter
8 	
g
10 	
1 1 	 	
12
13
14 . .
15 	
16 	
17
18
19
20
21 	
22
23 	
24 	 	 	

Number of traverse points on a diameter—
2










	







4


















6



8
96.8

	

'
I
j




















10
85.4
91.8
97.4














12"
75.0
82.3
88.2
93.3
97.9












14
63^4
73.1
79.9
85.4
90.1
94.3
98.2










16
37.5
62.5
71.7
78.0
83.1
87.5
91.5
95.1
98.4








18
29.6
38.2
61.3
70.4
76.4
81.2
85.4
89.1
92.5
95.6
98.6






20
25.0
30.6
38.8
61.2
69.4
75.0
79.6
33.5
87.1
90.3
93.3
96 j
98.7




22
21.8
26.2
31.5
39.3
60.7
68.5
73.8
78.2
82.0
85.4
88.4
91.3
94.0
96.5
98.9


24
19.4
23.0
27.2
32.3
39.8
60.2
67.7
72.8
77.0
80.6
83.9
86.8
89.5
92.1
94.5
96.3
98.9
  2.3.1.2  Stacks With  Diameters Equal to
.or Less Than 0.61 m (24 in.). Follow the pro-
cedure in Section 2.3.1.1,  noting only that
any "adjusted" points  should be relocated—
away from the stack walls to: (1) a distance
of 1.3 cm (0.50 in.); or (2) a distance equal to
the nozzle  inside  diameter,  whichever is
larger.
  2.3.2  Rectangular  Stacks. Determine the
number of  traverse points as explained in
Sections 2.1 and 2.2  of this method. Prom
Table  1-1, determine the grid configuration.
Divide the stack cross-section into as many
equal  rectangular elemental  areas as  tra-
verse  points, and  then  locate  a traverse
point at the centroid of each  equal area ac-
cording to the example  in Figure 1-4.
  If the tester desires to use more than the
minimum   number   of   traverse   points,
expand the "minimum number  of traverse
points" matrix (see Table 1-1) by adding the
extra traverse points along one or the other
or both legs of the matrix; the final  matrix
need not be balanced. For example, if a 4x3
"minimum number  of  points; matrix were
expanded to 36 points,  the final  matrix
could be 9x4 or 12x3, and would not neces-
sarily have to be 6x6. After constructing the
final matrix, divide  the stack cross-section
into as many equal  rectangular, elemental
areas as  traverse points, and locate a  tra-
verse point at the centroid of  each equal
area.
  The  situation of traverse points being too
close to the stack walls is  not  expected to
arise with rectangular  stacks. If this prob-
lem should  ever arise, the  Administrator
must be contacted   for resolution  of  the
matter.
  2.4 Verification of Absence  of Cyclonic
Flow. In most stationary sources, the direc-
tion of stack gas flow is essentially parallel
to the  stack walls.  However, cyclonic flow
may exist (1) after such devices as cyclones
and  inertial  demisters  following  venturi
scrubbers, or (2) in stacks having  tangential
inlets  or other  duct  configurations which
tend to  induce  swirling; in these instances,
the presence or absence of cyclonic flow at
the sampling location must be determined.
The following techniques are acceptable for
this determination.
            I
                    I
                           I
Figure 1-4. Example showing rectangular stack cross
section divided into 12 equal areas, with a traverse
point at centroid of each area.
  Level and zero the manometer. Connect a
Type S pitot  tube  to the manometer. Posi-
tion the Type S pitot tube  at each traverse
point, in succession, so that the planes of
the face openings of the pitot tube are per-
pendicular  to   the  stack  cross-sectional
plane; when the Type S pitot tube is in this
position, it is at "0° reference." Note the dif-
ferential pressure (Ap)  reading at each tra-
verse point. If a null (zero)  pitot reading is
obtained at 0° reference at  a given traverse
                                          115

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 Chapter I—Environmental Protection Agency
                                 App. A
 point, an acceptable flow condition exists at
 that point. If the pitot reading is not zero at
 0' reference, rotate the pitot  tube (up to
 =90* yaw angle), until a null reading  is ob-
 tained. Carefully determine and record the
 value of the rotation  angle (a) to the near-
 est degree. After  the null technique  has
 been applied at each traverse point, calcu-
 late the average of the absolute values of a;
 assign a values of 0* to those points for
 which no rotation was required, and include
 these in the overall average. If the average
 value of o is greater than 10°, the overall
 flow condition in the stack is  unacceptable
 and alternative methodology, subject to the
 approval of the Administrator, must be used
 to perform accurate sample and velocity tra-
 verses.

 3. Bibliography
  1. Determining Dust Concentration  in a
 Gas Stream, ASME. Performance Test Code
 No. 27. New York, 1957.
  2. Devorkin, Howard, et al. Air Pollution,
 Source Testing Manual. Air Pollution Con"
 trol  District. Los Angeles, CA. November
 1963.
  3. Methods for Determination of Velocity,
 Volume, Dust and Mist Content of Gases.
 Western Precipitation Division of Joy  Man-
 ufacturing  Co.  Los Angeles, CA.  Bulletin
 WP-50. 1968.
  4. Standard Method for Sampling Stacks
 for Particulate Matter. In: 1971 Book of
 ASTM Standards, Part 23. ASTM Designa-
 tion D-2928-71. Philadelphia, Pa. 1971.
  5. Hanson, H. A.,  et al.  Particulate  Sam-
 pling Strategies for  Large Power Plants In-
cluding  Nonuniform Plow. USEPA,  ORD,
ESRL, Research Triangle Park, N.C. EPA-
600/2-76-170, June 1976..
  6. Entropy Environmentalists, Inc. Deter-
mination of the Optimum Number of  Sam-
 pling Points: An Analysis of Method 1 Crite-
 ria. Environmental Protection  Agency,  Re-
 search Triangle Park, N.C. EPA  Contract
 No. 68-01-3172, Task 7.

 METHOD  2—DETERMINATION OP STACK GAS
  VELOCITY  AND  VOLUMETRIC  PLOW  RATE
  (TYPE S PITOT TUBE)

 1. Principle and Applicability
  1.1  Principle. The average gas velocity in
 a stack is determined from the gas density
 and from measurement of the average veloc-
 ity head with a Type S (Stausscheibe or re-
 verse type) pitot tube.
  1.2  Applicability. This method is applica-
 ble for measurement of the average velocity
 of a  gas stream and for  quantifying  gas
 flow.
  This procedure is not applicable at mea-
 surement sites which fail to meet the crite-
 ria  of Method  1,  Section 2.1. Also,  the
 method cannot be used for direct  measure-
 ment in cyclonic or  swirling gas  streams;
 Section 2.4 of Method 1 shows how to  deter-
 mine  cyclonic or swirling  flow conditions.
 When unacceptable  conditions  exist,  alter-
 native procedures, subject  to the  approval
 of the Administrator, U.S. Environmental
 Protection Agency, must  be employed  to
 make accurate flow rate determinations; ex-
 amples of such alternative procedures are:
 (1) to install straightening  vanes; (2) to cal-
 culate the total volumetric flow  rate stoi-
 chiometrically,  or  (3) to move to another
measurement site at which the flow  is ac-
ceptable.
 2. Apparatus
  Specifications for the apparatus are given
below. Any  other apparatus that has been
demonstrated (subject to  approval of  the
Administrator) to be capable of  meeting the
specifications will be considered acceptable.
                                        116

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 App. A
    Title 40—Protection of Environment
1.90-2.54 cm*
(0.75 -1.0 in.)
             7.62 cm (3 in.)
                             TEMPERATURE SENSOR
            •SUGGESTED (INTERFERENCE FREE)
            PITOT TUBE THERMOCOUPLE SPACING
                       Figure 2-1.  Type S pilot tube manometer assembly.
  2.1 Type S Pitot Tube. The Type S pitot
tube (Figure 2-1)  shall be made of metal
tubing (e.g. stainless steel). It is recommend-
ed that the external tubing diameter (di-
mension  D,  Figure 2-2b) be between  0.48
and 0.95 centimeters (%6 and % inch). There
shall be an equal distance from the base of
each leg of the pitot tube to its face-opening
plane (dimensions PA and Pa Figure 2-2b); it
is recommended that this  distance be be-
tween  1.05  and  1.50  times  the  external
tubing diameter. The face openings of the
pitot  tube shall,  preferably,  be aligned as
shown in  Figure 2-2; however,  slight  misa-
lignments of the openings are permissible
(see Figure 2-3).
  The Type S pitot tube shall have a known
coefficient, determined  as outlined in Sec-
tion 4. an  identification  number shall be as-
signed to  the pitot tube; this number shall
be permanently marked or engraved on the
body of the tube.
                                       117

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 Chapter I—Environmental Protection Agency
         APR.A
              TRANSVERSE
               TUBE AXIS
                            \
                                              FACE
                                            OPENING
                                            PLANES

                                                (a)
                                         A-SIDE PLANE
LONGITUDINAL ;
TUBE AXIS
? °t
i *
A
B
                                                         PA

                                                         PB
NOTE:

1.05 Ot< P<1.50Dt
                                        B-SIDE PLANE

                                          (b)
                                  A ORB
                                     (c)
Figure 2-2. Properly constructed Type S pilot tube, shown in: (a) end view; face opening planes perpendicular
to transverse axis; (b) top view; face opening planes parallel to longitudinal axis; (c) side view; both legs of
equal length and centerlines coincident, when viewed from both sides. Baseline coefficient values of 0.84 may
be assigned to pilot tubes constructed this way.
                                        118

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 App. A
Title 40—Protection of Environment
 TRANSVERSE
 TUBE AXIS
                               (a)
LONGITUDINAL
 TUBE AXIS	
                                (e)
                                                            02 (+ or •)
                                                               (-1- or -)
                                      119

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 Chapter I—Environmental Protection Agency
                                  App. A
                                         (f)
                                         (9)
 Figure 2-3. Types of face-opening misalignment that can result from field use or improper construction of
 Type S pilot tubes. These will not affect the baseline value of Cp(s) so long as al and a.2 10°, /31 and /32
 5'. z 0.32 cm (1/8 in.) and w 0.08 cm (1/32 in.) (citation 11 in Section 6).
  A standard pitot tube may be used instead—
 of  a  Type  S.  provided that  it meets  the
 specifications of Sections 2.7 and 4.2; note,
 however, that the static and impact pres-
 sure holes of standard pitot tubes are sus-
 ceptible to plugging in particulate-laden gas
 streams.  Therefore,  whenever a standard
 pitot tube is used to perform a traverse, ade-
 quate  proof must be  furnished that  the
 openings of the pitot tube have not plugged
 up  during the traverse period; this can be
 done by taking a velocity head (Ap) reading
 at the final traverse point, cleaning out the
 Impact and static holes of the standard
 pitot tube by "back-purging" with pressur-
 ized air, and then taking another Ap read-
 ing. If the Ap  readings  made before and
 after  the air purge are the same (±5 per-
 cent), the traverse is acceptable. Otherwise,
 reject  the run. Note that if  Ap at the final
 traverse point is unsuitably  low, another
 point may be selected. If  "back-purging" at
 regular intervals is  part  of  the procedure,
 then  comparative  Ap  readings  shall   be
 taken,  as above, for the  last two back purges
 at which suitably high Ap readings are ob-
served.
  2.2  Differential Pressure  Gauge.  An in-
clined  manometer  or equivalent device is
used.  Most sampling trains are equipped
with a 10-in. (water column) inclined-verti-
cal manometer, having 0.01-in. H,O divisions
on the 0-to 1-in. inclined scale,  and  0.1-in.
HjO divisions, on the 1-  to  10-in. vertical
scale.  This  type of manometer (or other
gauge  of equivalent sensitivity) is satisfac-
tory for the measurement of  Ap values as
low as 1.3 mm (0.05 in.) H3O. However, a dif-
ferential pressure gauge of greater sensitiv-
ity shall be used (subject to the approval of
the Administrator), if any of the following
is found to be true: (1) the arithmetic aver-
age of all Ap readings at the traverse points
in the stack is  less than 1.3 mm (0.05  in.)
H,O; (2) for traverses of  12 or more points,
more than  10 percent of the individual Ap
readings are below 1.3 mm (0.05 in.) H,O; (3)
for traverses of fewer than 12 points, more
than one Ap reading is below 1.3 mm (0.05
in.) H,O. Citation 18 in Section  6 describes
commercially available instrumentation for
the measurement  of low-range  gas  veloci-
ties.
  As an alternative to  criteria (1) through
(3) above, the following calculation may be
performed  to  determine  the necessity  of
using a more sensitive differential pressure
gauge:
                        _

                      VA?.*

where:
API=Individual velocity  head reading at a
   traverse point, mm H2O (in. HjO).
n=Total number of traverse points.
                                         120

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 App. A
    Title 40—Protection of Environment
 #=0.13 mm H2O when metric units are used
     and 0.005 in H,O when English units are
     used.

 If T is greater than 1.05, the  velocity head
 data are unacceptable and a more sensitive
 differential pressure gauge must be used.
   NOTE: If differential pressure gauges other
 than  inclined manometers  are used  (e.g.,
 magnehelic  gauges), their calibration must
 be checked after each test series. To check
 the calibration of a  differential pressure
 gauge, compare  Ap  readings  of the  gauge
 with those of a gauge-oil manometer at a
 minimum of  three  points, approximately
 representing the range of Ap  values in the
 stack. If, at each point, the values of Ap as
 read by the differential pressure gauge and
 gauge-oil manometer agree to  within  5 per-
 cent, the differential pressure gauge shall
 be considered to  be in proper calibration.
 Otherwise, the test, series shall  either  be
 voided,  or procedures  to  adjust the  meas-
 ured Ap values and final results  shall  be
 used subject to the approval of the Adminis-
 trator.
   2.3  Temperature  Gauge.  A thermocou-
 ple, liquid-filled bulb thermometer, bimetal-
 lic thermometer, mercury-in-glass thermom-
 eter, or other gauge, capable of measuring
 temperature  to within 1.5 percent of the"
 minimum absolute stack  temperature shall
 be used. The temperature gauge shall be at-
 tached  to the pitot tube such  that the
 sensor  tip does not  touch any metal; the
 gauge shall  be in  an interference-free ar-
 rangement with respect  to  the pitot tube
 face  openings (see  Figure  2-1  and  also
 Figure 2-7 in Section 4). Alternate positions
 may be  used  if the pitot  tube-temperature
 gauge system is calibrated according to the
 procedure of Section 4. Provided that a dif-
 ference of not more  than 1  percent in the
 average velocity measurement is introduced,
 the temperature gauge need not be attached
 to the pitot tube; this alternative is subject
 to the approval of the Administrator.
  2.4 Pressure Probe and Gauge. A  piezo-
 meter tube and mercury- or  water-filled U-
 tube manometer capable of measuring stack
 pressure to within 2.5 mm (0.1 in.)  Hg  is
 used. The static tap of a standard type pitot
 tube or one leg of a Type S pitot tube with
 the face opening planes positioned parallel
 to the gas flow may also be used as the pres-
sure probe.
  2.5  Barometer. A  mercury,  aneroid,  or
other barometer capable  of  measuring at-
mospheric pressure  to within  2.5  mm Hg
(0.1 in. Hg) may be used. In many cases, the
barometric reading may be obtained from a
nearby national weather service station, in
which case the station value (which is the
absolute barometric pressure)  shall be re-
 quested and an adjustment for elevation dif-
 ferences between the  weather station  and
 the sampling point shall be applied at a rate
 of minus 2.5 mm (0.1  in.)  Hg per 30-meter
 (100 foot)  elevation increase or vice-versa
 for elevation decrease.
   2.6  Gas  Density  Determination  Equip-
 ment. Method  3 equipment,  if needed (see
 Section 3.6), to determine the stack gas dry
 molecular weight, and  Reference Method 4
 or Method 5 equipment for moisture con-
 tent determination; other methods may be
 used subject to approval  of the Administra-
 tor.
   2.7  Calibration Pilot Tube. When calibra-
 tion  of  the Type S pitot tube  is necessary
 (see Section 4), a standard pitot tube is used
 as a  reference. The  standard  pitot  tube
 shall, preferably, have  a  known coefficient,
 obtained either (1) directly from the Nation-
 al Bureau of Standards,  Route 270, Quince
 Orchard Road, Gaithersburg, Maryland, or
 (2) by calibration against another standard
 pitot  tube  with an NBS-traceable  coeffi-
 cient. Alternatively,  a  standard pitot tube
 designed according to  the  criteria given in
 2.7.1 through 2.7.5 below and illustrated in
 Figure 2-4 (see  also Citations 7, 8, and 17 in
 Section 6) may be used. Pitot tubes designed
 according to  these specifications will have
 baseline coefficients of about 0.99±0.01.
  2.7.1  Hemispherical  (shown in Figure 2-
 4), ellipsoidal, or conical tip.
  2.7.2  A   minimum  of  six  , diameters
 straight run (based upon  D, the external di-
 ameter of the tube) between the tip and the
 static pressure holes.
  2.7.3  A  minimum  of   eight  diameters
 straight  run  between  the static pressure
 holes  and the  centerline of the external
 tube, following the 90 degree bend.
  2.7.4  Static pressure holes of equal size
 (approximately  0.1 D),  equally  spaced in a
 piezometer ring configuration.
  2.7.5  Ninety degree bend, with curved or
 mitered junction.
  2.8  Differential Pressure Gauge for Type
 S Pitot Tube Calibration.  An inclined mano-
 meter or equivalent is used. If the single-ve-
 locity calibration technique is employed (see
Section 4.1.2.3), the  calibration  differential
 pressure gauge shall be readable  to the
nearest 0.13  mm H,O (0.005 in. H,O). For
multivelocity  calibrations, the gauge shall
be readable  to  the  nearest 0.13  mm H,O
(0.005 in H,O) for Ap values between  1.3 and
25 mm H,O (0.05 and 1.0 in.  H,O),  and to
the nearest  1.3  mm  H,O  (0.05 in. H,O) for
Ap values above 25 mm  H,O (1.0 in. H,O). A
special, more sensitive gauge  will  be  re-
quired to read Ap values below 1.3 mm H,O
C0.05  in. H,O] (see Citation 18 in Section 6).
                                        121

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Chapter I—Environmental Protection Agency

       I             (*U.IUJ) Q8          l
                              App. A
            (•uiui)
                                   v>
                                   o
                                  '•M
                                   CO
                                   o
                                   a.
                                   V)
                                   C
                                  .5?
                                   Q)
                                  TJ
                                   cu
                                  J2
                                   D
                                   a.
                                  "O
                                   CO
                                  TJ
                                   C
                                   CO
                                  CM
                                   cu
                                   k.
                                   3
122

-------
 App. A

 3. Procedure
  3.1  Set up  the  apparatus as shown in
 Figure 2-1. Capillary tubing or surge tanks
 installed between the manometer and pitot
 tube may be  used  to  dampen Ap fluctu-
 ations. It is recommended, but not required,
 that a pretest leak-cheek be conducted, as
 follows: (1) blow through the pitot impact
 opening until at least 7.6 cm (3 in.) H,O ve-
 locity pressure registers on the manometer;
 then,  close off the impact opening. The
;pressure shall remain stable for at least 15
 seconds; (2) do the same for the static pres-
 sure side, except using suction to obtain the
 minimum of 7.6 cm (3 in.) H,O. Other leak-
 check procedures, subject to the approval of
 the Administrator may be used.
  3.2 Level and zero the manometer. Be-
 cause  the manometer level and  zero may
   Title 40—Protection of Environment

 drift due  to vibrations  and  temperature
 changes, make periodic  checks during the
 traverse. Record all necessary data as shown
 in the example data sheet (Figure 2-5).
  3.3 Measure the velocity head  and tem-
 perature at the traverse  points specified by
 Method 1.  Ensure that the proper differen-
 tial  pressure gauge is being used for the
 range of Ap values encountered (see Section
 2.2). If it is necessary to change to a more
 sensitive gauge, do so, and remeasure the Ap
 and  temperature  readings at each traverse
 point. Conduct a post-test leak-check (man-
 datory), as  described in Section 3.1  above, to
 validate the traverse run.
  3.4  Measure  the static pressure in  the
stack. One reading is usually adequate.
  3.5  Determine the atmospheric  pressure.
                                       123

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Chapter I—Environmental Protection Agency
                                                   APR. A
PLANT.
DATE
        .RUN NO.
STACK DIAMETER OR DIMENSIONS, m(in.)
BAROMETRIC PRESSURE, mm Hg (in. Hg)	
CROSS SECTIONAL AREA, m2{ft2)	
OPERATORS .	
PITOTTUBEI.D. NO.
  AVG. COEFFICIENT, Cp = .
  LAST DATE CALIBRATED.
                                       SCHEMATIC OF STACK
                                          CROSS SECTION
   Traverse
    Pt. No.
Vel.Hd.,Ap
mm (in.) HjO
                                  Stack Temperature
ts, °C (
mm Hg (in.Hg)
                                  Average
                      Figure 2-5.  Velocity traverse data.
                                     124

-------
 App. A

  3.6 Determine the stack gas dry molecular
 weight. For combustion  processes or proc-
 esses that emit essentially CO,, O,, CO, and
 N,. use Method 3. For processes emitting es-
 sentially  air, an analysis need not  be con-
 ducted; use a dry molecular weight of 29.0.
 For other processes, other methods, subject
 to the approval of the Administrator, must
 be used.
  3.7.Obtain  the  moisture content  from
 Reference Method 4 (or equivalent)  or from
 Method 5.
  3.8 Determine the cross-sectional  area of
 the  stack or duct at the  sampling location.
 Whenever possible, physically measure the
 stack dimensions  rather than using  blue-
 prints.

 4. Calibration
  4.1 Type S Pitot Tube. Before  its initial
 use, carefully examine the Type S  pitot
 tube in top, side, and end views to verify
 that the   face openings  of the  tube are
 aligned within the specifications illustrated"'
 in Figure  2-2 or 2-3.  The pitot tube  shall
 not  be used  if it fails to meet these align-
 ment specifications.
  After verifying  the  face  opening align-
 ment, measure and record the following di-
 mensions  of the pitot tube: (a) the external
 tubing diameter (dimension A, Figure 2-2b);
 and  (b) the base-to-opening plane distances
 (dimensions P* and Pa, Figure 2-2b). If D, is
 between 0.48 and 0.95 cm (.Vie and % in.) and
 if PM and Pa are equal and between 1.05 and
 1.50  D,. there are two possible options: (1)
 the pitot  tube may be calibrated according
 to the procedure outlined in Sections 4.1.2
 through 4.1.5 below, or (2) a baseline (isolat-
 ed tube) coefficient value  of 0.84 may be as-
signed to the pitot tube. Note, however, that
 if the pitot tube is part of an assembly, cali-
bration may still be required, despite knowl-
edge of the  baseline  coefficient value (see
Section 4.1.1).
    Title 40—Protection of Environment

  If D,, PA, and PB are outside the specified
 limits, the pitot tube must be calibrated as
 outlined in 4.1.2 through 4.1.5 below.
  4.1.1 Type  S   Pitot  Tube  Assemblies.
 During sample and  velocity traverses,  the
 isolated  Type S  pitot tube  is not  always
 used: in many instances, the pitot tube is
 used in combination  with other source-sam-
 pling components (thermocouple, sampling
 probe, nozzle) as part of an "assembly." The
 presence of other sampling components  can
 sometimes affect  the baseline value  of  the
 Type S pitot tube coefficient (Citation 9 in
 Section 6); therefore an assigned (or other-
 wise known) baseline coefficient value maj-
 or  may not be valid for a  given assembly.
 The  baseline  and  assembly coefficient
 values will be identical only when  the rela-
 tive placement of  the components in the as-
 sembly is such that aerodynamic  interfer-
 ence  effects  are  eliminated. Figures  2-6
 through  2-8  illustrate   interference-free
 component arrangements for Type S pitot
 tubes having external tubing diameters  be-
 tween 0.48 and 0.95 cm Cfte and % in.). Type
 S pitot tube assemblies that fail to meet any
 or  all  of  the  specifications  of Figures  2-6
 through 2-8 shall  be calibrated according to
 the procedure  outlined in  Sections 4.1.2
 through 4.1.5 below, and prior to calibra-
 tion, the values of the intercomponent spac-
 ings (pitot-nozzle,  pilot-thermocouple, pitot-
 probe sheath) shall be measured and record-
 ed.
  NOTE: Do not use any Type S pitot tube
 assembly which is  constructed such that the
 impact pressure opening plane of the pitot
 tube is below the  entry plane of the  nozzle
 (see Figure 2-6b).  •
  4.1.2  Calibration Setup. If  the  Type S
 pitot tube is to be calibrated, one leg  of the
tube shall be  permanently  marked A, and
the other, B. Calibration shall be done in a
flow system having the following essential
design features:
                                        125

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Chapter I—Environmental Protection Agency
                                         App. A
                  3E
TYPE 5 PITOT TUBE
I
                            x > 1.90 em (3/4 in.) FOR Dn - 1.3 em (1/2 in.)
                 SAMPLING NOZZLE
            A. BOTTOM VIEW; SHOWING MINIMUM PITOT-NOZZLE SEPARATION.
   SAMPLING
    PROBE
       I
SAMPLING
 NOZZLE
                 TYPE S
                PITOT TUBE
                               NOZZLEjENTRY
                                   PLANE
            B.  SIDE VIEW: TO PREVENT PITOT TUBE
               FROM INTERFERING WITH GAS FLOW
               STREAMLINES APPROACHING THE
               NOZZLE. THE IMPACT PRESSURE
               OPENING PLANE OF THE PITOT TUBE
               SHALL BE EVEN WITH OR ABOVE THE
               NOZZLE ENTRY PLANE.
                                      126

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App. A
       Title 40—Protection of Environment
                         1
                                       0)
                                       c
                                       
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Chapter I—Environmental Protection Agency
                                 App. A
  4.1.2.1  The flowing gas stream must be
confined to a duct of definite cross-sectional
area, either circular or rectangular. For cir-
cular  cross-sections,  the minimum duct di-
ameter shall  be 30.5  cm (12 in.); for rectan-
gular cross-sections, the width (shorter side)
shall be at least 25.4 cm (10 in.).
  4.1.2.2  The cross-sectional area  of the
calibration duct must be constant over a dis-
tance  of 10 or more  duct diameters. For a
rectangular cross-section, use an  equivalent
diameter, calculated from  the   following
equation, to determine the number of duct
diameters:
                    a/.ir
                                     '2-1
where:
D,—Equivalent diameter
Z,« Length
W'=Width
  To ensure the presence of stable, fully de-
veloped flow patterns at the calibration site,
or "test section," the site must be located at
least eight diameters downstream and two--
diameters upstream from the nearest distur-
bances.
  NOTE The eight- and two-diameter crite-
ria are not absolute: other test section loca-
tions may  be  used (subject to approval of
the Administrator), provided that the flow
at the  test site is  stable and demonstrably
parallel to the duct axis.
  4.1.2.3  The flow system shall have the ca-
pacity  to generate  a  test-section  velocity
around 915 m/min (3,000 ft/min). This ve-
locity must be constant with time to guaran-
tee steady flow during calibration. Note that
Type S pilot tube coefficients obtained by
single-velocity calibration  at  915  m/min
(3.000  ft/min) will  generally  be valid to
within ±3  percent for the measurement of
velocities above  305 m/min (1,000 ft/min)
and to within  ±5 to 6 percent for the mea-
surement of velocities between 180 and 305
m/min (600 and 1,000  ft/min).  If a  more
precise correlation between Cf and velocity
is desired, the flow system shall have the ca-
pacity  to generates at  least four  distinct,
time-invariant test-section velocities  cover-
ing the velocity range from 180 to 1,525 m/
min  (600 to 5,000 ft/min),  and calibration
data shall be taken at regular velocity inter-
vals over this range (see Citations 9 and 14
in Section 6 for details).
  4.1.2.4  Two entry ports, one each for the
standard and  Type S pitot tubes,  shall be
cut in the test section: the standard pitot
entry port shall be located slightly  down-
stream of  the Type S  port, so that the
standard and Type S  impact openings will
lie in the same cross-sectional plane during
calibration.  To facilitate alignment of the
pitot tubes during calibration, it is advisable
that the test section be constructed of plex-
iglas or some other transparent material.
  4.1.3  Calibration  Procedure.  Note that
this procedure is a general one and must not
be used without first referring to the special
considerations  presented in Section  4.1.5.
Note also that this  procedure applies only
to single-velocity calibration. To obtain cali-
bration data for  the A and  B sides of the
Type S pitot tube, proceed as follows:
  4.1.3.1  Make sure that the manometer is
properly filled and that the oil is free from
contamination and is of the proper density.
Inspect and leak-check all pitot lines; repair
or replace if necessary.
  4.1.3.2  Level and zero  the manometer.
Turn on the fan and allow the flow to stabi-
lize. Seal the Type S entry port.
  4.1.3.3  Ensure   that the  manometer  is
level and zeroed. Position the standard pitot
tube at the calibration point (determined as
outlined in Section  4.1.5.1), and align the
tube so that its tip  is  pointed directly into
the flow. Particular car should  be taken in
aligning the tube to  avoid  yaw and  pitch
angles. Make sure that the entry port sur-
rounding the tube is properly sealed.
  4.1.3.4  Read A',,,1 and record its value in a
data  table  similar  to the  one shown in
Figure 2-9. Remove the standard pitot tube
from the duct and  disconnect it  from the
manometer. Seal the standard entry port.
  4.1.3.5  Connect the  Type  S pitot tube to
the  manometer.  Open the  Type  S  entry
port. Check the manometer level  and zero.
Insert and align  the Type S pitot tube so
that its A side impact opening is at the same
point as was the  standard pitot tube and is
pointed  directly  into  the flow. Make sure
that the entry  port surrounding the tube is
properly sealed.
  4.1.3.6  Read Ap« and enter its value in the
data table.  Remove the Type S pitot tube
from the duct and  disconnect it  from the
manometer.
  4.1.3.7  Repeat  steps   4.1.3.3   through
4.1.3.6 above until three pairs of Ap readings
have been obtained.
  4.1.3.8 Repeat  steps   4.1.3.3   through
4.1.3.7 above for  the B side of  the Type S
pitot tube.
  4.1.3.9 Perform calculations, as described
in Section 4.1.4 below.
  4.1.4  Calculations.
  4.1.4.1  For  each of  the  six pairs of Ap
readings (i.e., three  from side A and three
from side B) obtained in Section 4.1.3 above,
calculate the value of the Type S pitot tube
coeffficient as follows:
                                        128

-------
App. A
 PITOT TUBE IDENTIFICATION NUMBER:
 CALIBRATED BY:	
 Title 40—Protection of Environment
	DATE:	

RUN NO.
1
2
3
"A" SIDE CALIBRATION
' Apjtd
cm H20
(in. H20)




Ap(s)
cm H20
(in. H20)



Cp (SIDE A)
Cp(s)





DEVIATION
Cp(s)-Cp(A)





RUN NO.
1
2
3
"B" SIDE CALIBRATION
Apjtd
cm H20
(in. H20)




Ap(s)
cm H20
(in. H20)



Cp (SIDE B)
cp(s)





DEVIATION
Cp(s)-Cp(BI




                                    I |Cp(s)-Cp(AORB)|
    AVERAGE DEVIATION = u (A OR B)
                   • MUST BE < 0.01
     Cp (SIDE A)-Cp (SIDE B) |-*-MUST BE <0.01

                  Figure 2-9. Pitot tube calibration data.
                                   129

-------
 Chapter I—Environmental Protection Agency
                                  App. A
                            Equation 2-2
where:
C,=Type S pitot tube coefficient
Cii,,a)=Standard pitot tube coefficient;  use
    0.99 if the coefficient is  unknown and
    the tube is designed according to the cri-
    teria of Sections 2.7.1  to 2.7.5 of this
    method.
•iPi«=Velocity head measured by the stand-
    ard pitot tube, cm H,O (in. H3O)
ip,=Velocity head measured by the Type S
    pitot tube, cm H,O (in H,O)

  4.1.4.2  Calculate Cp (side A), the mean A-
side coefficient, and C, (side B), the mean B-
side coefficient: calculate the difference be-
tween these two average values.
  4.1.4.3  Calculate the deviation of each of
the three  A-side values of CPt,> from Cf (side
A), and the deviation of each B-side value of
Cpui from  Cp Cp (side B).  Use the following..
equation:
      Deviation = Cp(.!—CV(A or B)

                            Equation 2-3
  4.1.4.4  Calculate S, the average deviation
from the mean, for both the A and B sides
of the pitot tube. Use  the following equa-
tion:
 a (side A or B):
                   3
                  2l
                   i
                             Equation 2-4
  4.1.4.5  Use the Type S pitot tube only if
Che values of S (side A) and S (side B) are
less than or equal to 0.01 and if the absolute
value of the difference between Cp (A) and
CB (B) is 0.01 or less.
  4.1.5 Special considerations.
  4.1.5.1  Selection of calibration point.
  4.1.5.1.1  When an isolated Type S pitot
tube is calibrated, select a calibration point
at or near the center of the duct, and follow
the procedures  outlined in Sections 4.1.3
and 4.1.4  above.  The Type  S  pitot  coeffi-
cients so obtained,  i.e., Cp (side A) and C,
 (side B), will be valid, so long as either: (1)
 the  isolated pitot  tube is used; or (2) the
 pitot tube  is used with  other components
 (nozzle, thermocouple, sample probe) in an
 arrangement that is free from aerodynamic
 interference   effects   (see   Figures   2-6
 through 2-8).
  4.1.5.1.2  For Type  S pitot  tube-thermo-
 couple   combinations   (without  sample
 probe), select a calibration point at or near
 the center of the duct, and follow the proce-
 dures outlined in  Sections  4.1.3 and  4.1.4
 above. The coefficients so obtained will be
 valid so long as the pitot tube-thermocouple
 combination is used by itself or with other
 components in an interference-free arrange-
 ment (Figures 2-6, and 2-8).
  4.1.5.1.3  For  assemblies   with  sample
 probes, the calibration point should be lo-
 cated at or near the center of the duct; how-
 ever, insertion of a probe  sheath  into a
 small duct  may cause  significant cross-sec-
 tional area blockage and yield incorrect co-
 efficient values (Citation 9 in  Section 6).
 Therefore, to minimize the blockage effect,
 the  calibration point may be  a few inches
 off-center if necessary. The actual blockage
 effect will be negligible when the theoreti-
 cal blockage, as determined by a projected-
 area model of the probe sheath, is 2 percent
 or less of the  duct cross-sectional area for
 assemblies without external sheaths (Figure
 2-10a), and 3 percent or less for assemblies
 with external sheaths (Figure 2-10b).
  4.1.5.2  For  those  probe  assemblies  in
 which pitot tube-nozzle  interference  is  a
 factor (i.e.,  those in which the pitot-nozzle
 separation distance fails to .meet the specifi-
 cation illustrated in Figure 2-6a), the value
 of Cp<.>  depends upon the amount of  free-
 space  between the tube  and  nozzle,  and
 therefore is a function of nozzle size. In
 these instances, separate calibrations shall
 be performed  with each  of the commonly
 used  nozzle  sizes  in place. Note that  the
single-velocity  calibration technique is ac-
 ceptable for this purpose, even though the
 larger nozzle sizes (>0.635 cm or '/< in.) are
 not ordinarily  used for isokinetic sampling
 at velocities around 915  m/min  (3,000 ft/
min), which is  the calibration velocity; note
 also  that it is not necessary to draw an iso-
 kinetic sample during calibration (see Cita-
 tion 19 in Section 6).
  4.1.5.3  For a probe assembly constructed
such that its pitot tube is always used in the
same orientation, only one side of the pitot
 tube need be calibrated (the side which will
face the flow). The  pitot tube must still
meet the alignment specifications of Figure
 2-2 or 2-3, however, and must have an aver-
age deviation (8) value of 0.01 or less (see
Section 4.1.4.4).
                                         130

-------
App. A
Title 40—Protection of Environment

                                                                           03
                                                                           
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                                                                           - * 55
S < «J •~"
H- UJ O
c/l X _j
UJ CO OQ
'a
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+^
o
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~z
~a
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-------
 Chapter I—Environmental Protection Agency
                                  App. A
Figure 2-10. Projected-area models for typi-
cal pitot tube assemblies.
  4.1.6  Field Use and Recalibration.
  4.1.6.1 Field Use.
  4.1.6.1.1  When a Type S pitot  tube (iso-
lated tube  or assembly) is used in the field,
the appropriate coefficient value (whether
assigned or obtained by calibration) shall be
used  to  perform velocity calculations.  For
calibrated Type S pitot tubes, the  A side co-
efficient shall  be used when  the  A side of
the tube faces the flow, and the B side coef-
ficient shall be used when the B  side faces
the flow; alternatively, the arithmetic aver-
age of the A and B side coefficient  values
may be used, irrespective of which side faces
the flow.
  4.1.6.1.2  When a probe assembly is used
to sample a small duct (12 to 36 in. in diame-
ter), the probe sheath sometimes blocks a
significant  part of the duct cross-section,
causing a reduction in the effective value of
Cpui. Consult Citation 9 in Section 6 for de-
tails.  Conventional pitot-sampling probe as-
semblies are not recommended for use in
ducts having inside diameters smaller than
12 inches (Citation 16 in Section 6).
  4.1.6'.2  Recalibration.
  4.1.6.2.1  Isolated  Pitot Tubes. After each,
field use, the pitot tube shall be carefully"
reexamined in  top,  side, and  end views. If
the pitot  face openings are still aligned
within  the  specifications   illustrated  in
Figure 2-2 or 2-3, it can be assumed that the
baseline coefficient of the pitot tube has not
changed. If,  however,  the  tube  has been
damanged  to the extent that it no longer
meets the specifications of Figure 2-2 or 2-
3, the damage shall  either be repaired to re-
store proper alignment of the face openings
or the tube shall be discarded.
  4.1.6.2.2  Pitot  Tube  Assemblies.  After
each field use, check the face opening align-
ment of  the   pitot  tube,  as  in Section
4.1.6.2.1; also, remeasure the  intercompon-
ent spacings of the assembly. If the inter-
component spacings  have not changed and
the face opening alignment is acceptable, it
can be assumed that  the coefficient of the
assembly has not changed. If the face open-
Ing alignment is no  longer within the speci-
fications of Figures  2-2 or 2-3, either repair
the damage or  replace the pitot tube (cali-
brating the new assembly, if necessary). If
the intercomponent spacings have changed,
restore the original spacings or recalibrate
the assembly.
  4.2  Standard pitot tube (if applicable). If
a standard  pitot tube is used for the velocity
traverse, the tube shall be constructed ac-
cording to  the  'criteria of Section 2.7 and
shall be assigned a baseline coefficient value
of 0.99. If the standard pitot tube is used as
part of an assembly, the tube shall be in an
interference-free  arrangement (subject  to
the approval of  the Administrator).
  4.3  Temperature   Gauges.  After  each
field  use,  calibrate  dial  thermometers,
liquid-filled bulb thermometers, thermocou-
ple-potentiometer   systems,   and  other
gauges  at a temperature within  10 percent
of the average absolute stack  temperature.
For temperatures up to 405° C (761° F),  use
an ASTM mercury-in-glass reference ther-
mometer, or equivalent, as a reference; al-
ternatively, either a reference thermocouple
and  potentiometer (calibrated by  NBS) or
thermometric fixed points, e.g., ice bath and
boiling water (corrected for barometric pres-
sure) may be  used. For temperatures above
405° C (761° F), use an NBS-calibrated refer-
ence thermocouple-potentiometer system or
an alternate  reference,  subject  to  the  ap-
proval of the Administrator.
  If, during calibration, the absolute tem-
peratures measured with  the  gauge being
calibrated  and the  reference  gauge agree
within  1.5 percent, the  temperature data
taken in the field shall be considered valid.
Otherwise, the pollutant emission test shall
either be considered invalid or adjustments
(if appropriate) of the test results shall be
made, subject  to the approval of the Admin-
istrator.
  4.4  Barometer. Calibrate  the  barometer
used against a mercury barometer.

5. Calculations

  Carry out calculations, retaining at least
one extra decimal figure beyond that of the
acquired data. Round off figures after final
calculation.
  5.1  Nomenclature.

A=Cross-sectional area of stack, mMft2).
Bun=Water vapor in the gas stream (from
   Method 5  or Reference Method 4), pro-
   portion by volume.
CP=Pitot tube coefficient, dimensionless.
Kf=Pitot tube constant.
    •U Q- -'-
          sec L   (°K)(mmH2O)  J


for the metric system and
         _ft_ f( Ib/lb-mole) (in. _Hg)-|«.
         sec L   (°R)(in. H20)   J
for the English system.

Ma = Molecular weight of stack gas, dry basis
   (see Section 3.6) g/g-mole (Ib/lb-mole).
A£r=Molecular  weight  of stack  gas,  wet
   basis, g/g-mole (Ib/lb-mole).
=Af« (1-.R,,) +18.0 Bw,
                                        132

-------
 APR. A
   Title 40—Protection of Environment
                             Equation 2-5

 P>ae= Barometric  pressure at measurement
    site, mm Hg (in. Hg).
 P,= Stack static pressure, mm Hg (in. Hg).

 P, = Absolute stack gas pressure, mm Hg (in.
    Hg).
                             Equation 2-6
 P,u= Standard  absolute pressure,  760 mm
    Hg (29.92 in. Hg).
 Q«i=Dry volumetric stack gas flow rate cor-
    rected to standard conditions,  dscm/hr
    (dscf/hr).
 4,= Stack temperature, °C (°F).
 T,= Absolute stack temperature, °K. OR).
 =273 +t, for metric
                             Equation 2-7
 =460+ 1. for English
                             Equation 2-3
 r,«=Standard absolute temperature, 293 °K
    (528° R)
 w= Average  stack gas  velocity, m/sec (ft/
    sec).
 &?= Velocity head of stack gas, mm HaO (in.
    H,O).
 3,600=Conversion factor, sec/hr.
 18.0= Molecular weight  of water, g/g-mole
    (Ib/lb-mole).
 5.2 Average stack gas velocity.
                           Equation 2-9
5.3 Average stack gas dry volumetric flow
rate.
 ^=3,600 (l-
                          Equation 2-10
6.  Bibliography

  1.  Mark,  L.  S.  Mechanical Engineers'
Handbook. New York, McGraw-Hill Book
Co., Inc. 1951.
  2. Perry, J. H. Chemical Engineers' Hand-
book. New York.  McGraw-Hill Book Co.,
Inc. 1960.
  3. Shigehara, R. T., W. P. Todd, and W. S.
Smith. Significance of Errors in Stack Sam-
pling Measurements. U.S.  Environmental
Protection Agency, Research Triangle Park,
N.C. (Presented at the Annual Meeting of
 the Air Pollution Control Association, St.
 Louis. Mo., June 14-19, 1970.)
  4. Standard Method for Sampling Stacks
 for  Particulate  Matter.  In:  1971  Book  of
 ASTM Standards, Part 23. Philadelphia, Pa.
 1971. ASTM Designation D-2928-71.
  5, Vennard, J.  K.  Elementary Fluid Me-
 chanics. New York.  John Wiley and Sons,
 Inc. 1947.
  6. Fluid Meters—Their Theory and Appli-
 cation. American Society of Mechanical En-
 gineers, New York, N.Y. 1959.
  7. ASHRAE Handbook of Fundamentals.
 1972. p. 208.
  8. Annual Book of  ASTM Standards, Part
 26. 1974. p. 648.
  9. Vollaro, R. F. Guidelines  for  Type S
 Pitot Tube Calibration. U.S. Environmental
 Protection Agency. Research Triangle Park,
 N.C.  (Presented  at   1st  Annual Meeting,
 Source Evaluation Society,  Dayton,  Ohio,
 September 18, 1975.)
  10. Vollaro, R. F.  A Type S Pitot Tube
 Calibration Study. U.S. Environmental Pro-
 tection  Agency,  Emission   Measurement
 Branch,  Research Triangle Park, N.C. July
 1974.
  11. Vollaro, R.  F. The  Effects of Impact
 Opening Misalignment on the Value of the
 Type S Pitot Tube Coefficient. U.S.  Envi-
 ronmental  Protection  Agency,  Emission
 Measurement Branch, Research Triangle
 Park, N.C. October 1976.
  12. Vollaro, R. F. Establishment of a Bas-
 line Coefficient Value for  Properly Con-
 structed Type S Pitot Tubes. U.S. Environ-
 mental Protection Agency, Emission Mea-
 surement Branch, Research Triangle Park
 N.C. November 1976.
  13. Vollaro, R. F. An Evaluation of Single-
 Velocity Calibration Technique  as a Means
 of Determining Type  S Pitot Tubes Coeffi-
 cient.   U.S.   Environmental   Protection
 Agency, Emission Measurement Branch, Re-
 search Triangle Park N.C. August 1975.
  14. Vollaro, R. F. The Use of Type S Pitot
 Tubes for the Measurement  of Low Veloci-
 ties. U.S. Environmental Protection Agency,
 Emission  Measurement Branch, Research
 Triangle Park N.C. November 1976.
  15. Smith, Marvin L. Velocity Calibration
 of  EPA  Type  Source  Sampling  Probe.
 United Technologies Corporation, Pratt and
 Whitney Aircraft Division, East Hartford,
 Conn. 1975.
  16.  Vollaro, R. F.  Recommended Proce-
 dure for Sample Traverses in Ducts Smaller
 than  12 Inches in Diameter.  U.S. Environ-
 mental  Protection Agency, Emission  Mea-
surement Branch. Research  Triangle Park
N.C. November 1976.
  17.  Ower.  E. and R. C. Pankhurst.  The
Measurement of Air Flow, 4th Ed., London,
Pergamon Press. 1966.
  18. Vollaro, R. F. A Survey of Commercial-
ly Available Instrumentation for the  Mea-
                                       133

-------
 Chapter I—Environmental Protection Agency
                                 App. A
 surement of Low-Range Gas Velocities. U.S.
 Environmental Protection Agency, Emission
 Measurement Branch,  Research  Triangle
 Park N.C.  November 1976.  (Unpublished
 Paper)  •
  19. Gnyp, A. W.. C. C. St.  Pierre, D. S.
 Smith, D. Mozzon, and ,T. Steiner. An  Ex-
 perimental  Investigation  of the Effect of
 Pitot Tube-Sampling Probe Configurations
 on the Magnitude of the S Type Pitot Tube
 Coefficient  for  Commercially  Available
 Source Sampling Probes.  Prepared by  the
 University of  Windsor for the Ministry of
 the Environment, Toronto, Canada. Febru-
 ary 1975.

 METHOD 3—GAS ANALYSIS FOR CARBON DIOX-
  IDE. OXYGEN, EXCESS AIR, AND DRY MOLEC-
  ULAR WEIGHT

 1. Principle and Applicability
  1.1  Principle. A gas sample  is extracted
 from a stack, by one of the following meth-
 ods:  (1)  single-point,  grab sampling;  (2r~
 single-point,  integrated sampling;  or  (3)
 multi-point,  integrated sampling. The  gas
 sample is analyzed for percent carbon diox-
 ide (CO,), percent oxygen (Oa), and, if neces-
 sary, percent  carbon  monoxide (CO). If a
 dry molecular  weight determination is to be
 made, either an Orsat or a Fyrite ' analyzer
 may  be used for the analysis; for excess air
 or emission  rate correction factor  determi-
 nation, an Orsat analyzer must  be used.
  1.2  Applicability. This method is applica-
 ble for determining Cd and O, concentra-
 tions, excess air, and dry molecular weight
 of a  sample  from a gas stream of a fossil-
fuel combustion process. The method may
also be applicable to other processes where
it has been determined that  compounds
  'Mention of trade names or specific prod-
ucts does not constitute endorsement by the
Environmental Protection Agency.
 other than CO2, Oa, CO, and nitrogen (n.)
 are not present in concentrations sufficient
 to affect the results.
   Other methods, as well as modifications to
 the procedure described herein, are also ap-
 plicable for some or all of the above deter-
 minations.  Examples  of specific  methods
 and modifications include: (Da multi-point
 sampling method using an Orsat analyzer to
 analyze individual grab samples obtained at
 each point; (2)  a method using CO3 or Oj
 and stoichiometric calculations to determine
 dry molecular weight and excess air; (3) as-
 signing a value of 30.0  for  dry molecular
 weight, in lieu of actual  measurements, for
 processes  burning natural gas, coal, or oil.
 These methods and modifications  may  be
 used, but are subject to the approval of the
 Administrator, U.S. Environmental Protec-
 tion Agency.
 2. Apparatus
  As an alternative to the sampling appara-
 tus  and systems described  herein,  other
 sampling systems (e.g., liquid displacement)
 may be used provided  such systems are ca-
 pable of obtaining a representative sample
 and maintaining a constant sampling rate,
 and are otherwise  capable of yielding ac-
 ceptable results. Use of such systems is sub-
 ject to the approval of the Administrator.
  2.1  Grab Sampling (Figure 3-1).
  2.1.1 Probe. The probe should be made of
 stainless steel or borosilicate glass  tubing
 and should be equipped with an in-stack or
 out-stack filter to remove particulate matter
 (a plug of glass wool is satisfactory for this
 purpose). Any other materials inert to O,,
 CO,. CO, and N, and resistant to tempera-
 ture at sampling conditions may be used for
 the probe;  examples of  such material are
 aluminum, copper, quartz glass and Teflon.
  2.1.2 Pump. A one-way squeeze  bulb, or
 equivalent, is used to transport  the gas
sample to the analyzer.
  2.2  Integrated Sampling (Figure 3-2).
  2.2.1 Probe. A probe  such as that de-
scribed in Section 2.1.1 is suitable.
                                        134

-------
APP.A
   Title 40—Protection of Environment
                        PROBE
                                               FLEXIBLE TUBING
            \
                FILTER (GLASS WOOL)
                            TO ANALYZER
                                    SQUEEZE BULB
                                 Figure 3-1. Grab-sampling train.
                                                RATE METER
          AIR-COOLED
          CONDENSER
PROBE
    \
       FILTER
     (GLASS WOOL)
                                           VALVE
                                               QUICK DISCONNECT

                                                          JT	
                                      RIGID CONTAINER '
                                                                         BAG
                          Figure 3-2. Integrated gas-sampling train.
  2.2.2  Condenser. An air-cooled or water-
 cooled condenser, or other condenser that
 will not remove O,, CO,, CO, and N*. may be
 used  to  remove  excess  moisture  which
 would interfere with  the operation  of the
 pump and now meter.
  2.2.3  Valve.  A needle valve is used to
adjust sample gas flow rate.
  2.2.4  Pump.  A leak-free, diaphragm-type
pump,  or  equivalent, is used to  transport
sample gas to the flexible bag.  Install a
small surge  tank between the pump  and
                                       135

-------
Chapter I—Environmental Protection Agency
                                 App. A
rate meter to eliminate the pulsation effect
of the diaphragm pump on the rotameter.
  2.2.5  Rate  Meter.  The  rotameter,   or
equivalent rate meter, used should be capa-
ble of measuring flow rate to within ±2 per-
cent of the  selected flow rate. A flow rate
range of 500 to 1000 cmVmin is suggested.
  2.2.6  Flexible Bag.  Any leak-free plastic
(e.g., Tedlar,  Mylar. Teflon) or  plastic-
coated  aluminum  (e.g.,  aluminized Mylar)
bag, or equivalent, having  a capacity con-
sistent  with  the selected flow rate and time
length  of the  test run, may be used. A ca-
pacity in the range of 55 to 90 liters is sug-
gested.
  To leak-check the bag. connect  it to a
water manometer and pressurize the bag to
5 to 10 cm H,O (2 to 4 in. HiO). Allow to
stand for 10 minutes. Any  displacement in
the water manometer indicates a leak.  An
alternative leak-check method is to pressur-
ize the  bag to 5 to 10 cm H,O (2 to 4 in. H,O)
and allow to stand overnight. A deflated bag
indicates a leak.
  2.2.7  Pressure Gauge.  A water-filled U-
tube manometer, or equivalent, of about 28
cm (12  in.) is used for the flexible bag leak-
check.
  2.2.8  Vacuum Gauge. A  mercury mano-
meter, or equivalent, of at least 760 mm Hg
(30 in.  Hg) is  used for the sampling  train"
leak-check.
  2.3 Analysis. For Orsat and Fyrite ana-
lyzer maintenance and  operation proce-
dures, follow the instructions recommended
by the manufacturer, unless otherwise spec-
ified herein.
  2.3.1  Dry  Molecular Weight Determina-
tion. An Orsat analyzer or Fyrite type com-
bustion gas analyzer may be used.
  2.3.2  Emission Rate Correction Factor or
Excess  Air Determination. An Orsat analyz-
er must be used. For low CO3 (less than 4.0
percent) or high Oi (greater that 15.0 per-
cent) concentrations, the measuring burette
of the Orsat must have at least 0.1 percent
subdivisions.

3. Dry Molecular Weight Determination
  Any of the three sampling and analytical
procedures described below may be used for
determining  the dry molecular weight.
  3.1 Single-Point,  Grab  Sampling   and
Analytical Procedure.
  3.1.1  The  sampling  point  in the  duct
shall either be at the centroid of the  cross
section or  at a point no closer to the  walls
than 1.00 m  (3.3 ft), unless otherwise speci-
fied by  the Administrator.
  3.1.2  Set up the equipment as shown in
Figure  3-1,  making sure all connections
ahead of the analyzer are  tight and  leak-
free. If and Orsat analyzer is used, it is rec-
ommended  that the  analyzer be  leaked-
checked by following the procedure in Sec-
tion 5: however, the leak-check is optional.
  3.1.3  Place  the  probe in the stack,  with
the tip  of the probe positioned at the  sam-
pling point; purge the sampling line. Draw a
sample  into the analyzer and immediately
analyze it for percent CO* and percent O3.
Determine the percentage of the gas that is
Ni and  CO by subtracting the sum of the
percent CO3 and percent O»  from 100 per-
cent.  Calculate the dry molecular weight as
indicated in Section 6.3.
  3.1.4  Repeat the sampling,  analysis, and
calculation procedures, until the dry molec-
ular  weights  of  any  three  grab samples
differ from their mean by no more than 0.3
g/g-mole  (0.3  Ib/lb-mole).  Average  these
three molecular weights, and report the re-
sults  to the  nearest  0.1 g/g-mole  (Ib/lb-
mole).
  3.2  Single-Point,  Integrated   Sampling
and Analytical Procedure.
  3.2.1  The sampling  point  in  the  duct
shall  be located as specified in Section 3.1.1.
  3.2.2  Leak-check (optional) the  flexible
bag as in Section 2.2.6. Set up  the equip-
ment as shown in Figure 3-2. Just prior to
sampling,  leak-check (optional) the train by
placing  a  vacuum gauge  at the  condenser
inlet, pulling a vacuum of at least 250 mm
Hg (10  in. Hg), plugging the outlet at the
quick disconnect, and  then turning off the
pump. The vacuum should remain stable for
at least 0.5 minute. Evacuate the  flexible
bag. Connect the probe and place it in the
stack, with the tip of  the probe positioned
at the sampling point; purge the sampling
line. Next, connect the bag and make sure
that all connections are tight and leak free.
  3.2.3  Sample at a constant rate. The sam-
pling run should be simultaneous with, and
for the same total length of time as, the pol-
lutant emission rate determination. Collec-
tion of at  least 30 liters (1.00 ft3)  of sample
gas is recommended;  however, smaller vol-
umes may be collected, if desired.
  3.2.4  Obtain  one  integrated  flue   gas
sample during each pollutant emission rate
determination. Within 8 hours  after  the
sample is  taken, analyze it for percent COi
and percent O, using either an Orsat analyz-
er or  a Fyrite-type combustion gas analyzer.
If an Orsat analyzer  is used, it  is recom-
mended that the Orsat leak-check described
in Section 5 be performed before this deter-
mination;  however, the  check is optional.
Determine the percentage of the gas that is
N, and  CO by subtracting the sum of the
percent Cd and  percent O> from 100 per-
cent.  Calculate the dry molecular weight as
indicated in Section 6.3.
  3.2.5  Repeat the analysis and calculation
procedures until the individual dry molecu-
lar weights for  any three analyses differ
from  their mean by no more than 0.3 g/g-
mole  (0.3  Ib/lb-mole).  Average these three
molecular weights, and report the results to
the nearest 0.1 g/g-mole (0.1 Ib/lb-mole).
                                       136

-------
 App. A
   Title 40—Protection of Environment
  3.3 Multi-Point, Integrated Sampling and
 Analytical Procedure.
  3.3.1  Unless otherwise specified  by the
 Administrator, a minimum of eight traverse
 points  shall  be used  for  circular  stacks
 having  diameters less than 0.61 m (24 in.), a
 minimum of nine shall be used for rectangu-
 lar stacks  having equivalent diameters less
 than 0.61  m  (24 in.),  and a minimum of
 twelve traverse points shall be used for all
 other cases. The traverse points shall be lo-
 cated according to Method  1. The use of
 fewer points is subject to approval of the
 Administrator.
  3.3.2  Follow the procedures  outlined in
 sections 3.2.2 through!  3.2.5. except for the
 following:  traverse all sampling points and
 sample  at each point for an equal length of
 time. Record  sampling data as shown in
 Figure 3-3.

 4.  Emission  Rate  Correction  Factor  or
 Excess Air Determination

  NOTE: A  Fyrite-type combustion gas ana-
 lyzer is not acceptable for excess air or emis-
 sion  rate correction factor determination.
 unless approved by  the Administrator.  If
 both percent CO, and percent O, are meas-
 ured, the analytical  results of  any of the
 three procedures  given  below may also be
 used for  calculating the dry  molecular
 weight.
  Each of the three procedures  below shall
 be used .only when specified in an applicable
 subpart of the standards. The use of these
 procedures  for  other purposes  must  have
 specific prior approval of the Administrator.

  4.1 Single-Point,   Grab  Sampling   and
 Analytical Procedure.
  4.1.1  The sampling  point in the  duct
 shall either be at  the centroid of the cross-
 section or at a point no closer to the  walls
 than 1.00 m (3.3 ft), unless otherwise speci-
 fied by the Administrator.
  4.1.2  Set up the equipment as shown in
 Figure  3-1, making  sure  all connections
 ahead of the  analyzer are tight and  leak-
 free. Leak-check the Orsat analyzer accord-
 ing to the procedure described in Section 5.
 This leak-check is mandatory.
TIME




TRAVERSE
PT.




AVERAGE
Q
1pm





% DEV.a





          %DEV=
                          Qavg
  (MUST BE < 10%)
                               Figure 3-3. Sampling rate data.
  4.1.3  Place the probe in the stack,  with
the tip of the probe positioned at the  sam-
pling point; purge the sampling line. Draw a
sample into the analyzer. For emission rate
correction factor determination, immediate-
ly analyze  the sample, as outlined in Sec-
tions 4.1.4 and 4.1.5, for percent CO, or per-
cent O». If excess air is desired, proceed as
follows: (1) immediately analyze the sample,
as in Sections  4.1.4  and 4.1.5, for percent
CO,, O,, and CO; (2) determine the percent-
age of  the gas that is N, by subtracting the
                                        137

-------
Chapter I—Environmental Protection Agency
                                 App. A
sum of the percent CO3. percent O3, and per-
cent CO from 100 percent; and (3) calculate
percent excess air as outlined in Section 6.2.
  4.1.4 To insure complete  absorption of
the COi. Oi, or if applicable, CO, make re-
peated passes through each absorbing solu-
tion until two consecutive readings are  the
same. Several passes (three or four) should
be  made  between  readings.  (If  constant
readings cannot be obtained after three con-
secutive readings, replace the absorbing so-
lution.)
  4.1.5 After  the  analysis  is  completed,
leak-check (mandatory) the Orsat analyzer
once again, as described in Section 5. For
the results of  the analysis to be valid,  the
Orsat  analyzer  must  pass  this  leak test
before and after the analysis.

  NOTE Since  this  single-point, grab sam-
pling  and analytical procedure in normally
conducted .in  conjunction with  a single-
point, grab sampling  and analytical proce-
dure for a pollutant, only one analysis is or-
dinarily conducted. Therefore,  great care
must be taken to obtain a valid sample and
analysis.  Although in most cases only CO,
or Oi is  required, it is recommended that
both COi and O, be measured, and that Ci-
tation 5 in the Bibliography be used to vali-
date the analytical data.
  4.2  Single-Point,   Integrated   Sampling
and Analytical Procedure.
  4.2.1 The sampling point  in  the duct
shall be located as specified in Section 4.1.1.
  4.2.2 Leak-check  (mandatory)  the  flexi-
ble bag as in Section 2.2.6. Set up the equip-
ment  as shown in Figure 3-2. Just prior to
sampling, leak-check (mandatory) the train '
by placing a vacuum gauge at  the condenser
inlet, pulling a vacuum of a least 250 mm Hg
(10 in. Hg), plugging the outlet at the quick
disconnect, and then turning  off the pump.
The vacuum shall remain stable for at least
0.5 minute. Evacuate the flexible bag. Con-
nect the probe and place it  in the stack.
with the tip of the probe positioned at  the
sampling point;  purge the sampling line.
Next,  connect  the bag and make sure that
all connections are tight and leak free.
  4.2.3 Sample at  a  constant rate,  or  as
specified  by the  Administrator.  The sam-
pling  run must be simultaneous  with, and
for the same total lengh of time as, the pol-
lutant emission rate determination. Collect
at least 30 liters (1.00 ft3) of sample gas.
Smaller volumes may be collected, subject
to approval of the Administrator.
  4.2.4 Obtain   one  integrated  flue  gas
sample during each pollutant emission rate
determination. For emission rate correction
factor  determination, analyze  the sample
within 4 hours after it is taken for percent
COi or percent O, (as outlined in Sections
4.2.5 through  4.2.7).  The Orsat analyzer
must  be  leak-check (see Section 5)  before
the analysis. If excess air is desired, proceed
as follows:  (1)  within 4 hours after the
sample  is taken, analyze  it (as  in Sections
4.2.5 through 4.2.7) for percent CO3, O,, and
CO; (2)  determine the percentage of the gas
that is N3 by subtracting the sum of the per-
cent CO,, percent O3, and percent CO from
100 percent; (3) calculate percent excess air,
as outlined in Section 6.2.
  4.2.5  To  insure  complete absorption of
the COi, Oj, or  if applicable, CO, make re-
peated passes  through each absorbing solu-
tion until two consecutive readings are the
same. Several  passes (three of four) should
be  make between readings.  (If  constant
readings cannot be obtained after three con-
secutive readings, replace the absorbing so-
lution.)
  4.2.6  Repeat  the analysis until the fol-
lowing criteria are met:
  4.2.6.1 For percent CO>, repeat the ana-
lytical procedure  until the results of any
three analyses differ by no more that  (a) 0.3
percent by volume when CO, is greater than
4.0 percent or (b) 0.2  percent  by volume
when COj is less than  or equal to 4.0 per-
cent. Average the three acceptable values of
percent COj and report the results to the
nearest  0.1 percent.
  4.2.6.2 For percent Oj, repeat the analyt-
ical procedure until the results of any three
analyses differ by no more than (a) 0.3 per-
cent by volume when O, is less than 15.0
percent or (b) 0.2 percent by volume when
O, is greater than or equal  to 15.0 percent.
Average the three acceptable values of per-
cent Oj  and report the results to the nearest
0.1 percent.
  4.2.6.3 For percent CO, repeat the ana-
lytical procedure  until the results of any
three analyses differ by no more than 0.3
percent.  Average  the  three  acceptable
values of percent CO and report the results
to the nearest 0.1 percent.
  4.2.7  After  the  analysis  is  completed.
leak-check (mandatory) the Orsat analyzer
once again, as described in Section 5. For
the results of the analysis to be valid, the
Orsat analyzer  must  pass this leak  test
before an after the analysis.

  NOTE:   Although  in most instances only
CO,  or  O3 is  required, it is recommended
that both CO, and O, be measured, and that
Citation 5 in  the Bibliography  be used to
validate the analytical data.
  4.3  Multi-Point, Integrated Sampling and
Analytical Procedure.
  4.3.1  Both the minimum number of sam-
pling points and the sampling point location
shall be as specified in  Section 3.3.1 of this
method. The use of fewer points than speci-
fied is subject to the approval of the Admin-
istrator.
  4.3.2  Follow the procedures outlined in
Sections 4.2.2 through 4.2.7, except for the
following: Traverse all sampling points and
                                        138

-------
  APP. A

  sample at each point for an equal length of
  time.  Record  sampling data as shown  in
  Figure 3-3.


  5. Leak-Check Procedure for Orsat Analyzers
   Moving  an  Orsat  analyzer  frequently
  causes it to leak. Therefore, an Orsat ana-
  lyzer should be throughly leak-checked on
  site before the flue gas sample is introduced
  into it. The procedure for leak-checking an
  Orsat analyzer is:
   5.1.1  Bring  the  liquid level in each  pi-
  pette up to the reference mark on the capil-
  lary tubing and then close the pipette stop-
  cock.
   5.1.2 Raise the leveling bulb sufficiently
  to bring  the confining liquid meniscus onto
  the graduated portion of  the  burette and
  then close the manifold stopcock.
   5.1.3 Record the  meniscus position.
   5.1.4 Observe the menicus in the burette
  and the liquid level in the pipette for move-
  ment over the next  4 minutes.
   5.1.5 For the Orsat  analyzer to pass the
  leak-check, two conditions must be met.
   5.1.5.1  The liquid level  in  each pipette
 must not fall below the bottom of the capil-
 lary tubing during this  4-minute interval.
   5.1.5.2  The meniscus in the burette must
 not change by more than 0.2 ml during this
 4-minute interval.
   5.1.6  If the analyzer fails the leak-check
 procedure, all rubber connections and stop-
 cocks should  be checked until the cause of
 the leak  is Identified. Leaking  stopcocks
 must  be  disassembled,  cleaned,  and  re-
 greased. Leaking rubber connections must
 be replaced. After the  analyzer is reassem-
 bled, the leak-check procedure  must be re-
 peated.

 8. Calculations

  6.1 Nomenclature.

 Ma=Dry molecular weight, g/g-mole Ub/lb-
    mole).
 %EA=Percent excess air.
 %CO3=Percent CO, by volume (dry basis).
 %O3=Percent O, by volume (dry basis).
 %CO=Percent CO by volume (dry basis).
 %N,=Percent N, by volume (dry basis).
 0.264=Ratio of O, to N, in air, v/v.
 0.280=Molecular weight of N, or CO, divid-
    ed by 100.
 0.320=Molecular weight  of  O,  divided bv
    100.
 0.440=Molecular weight of  CO, divided by
    100.

  6.2  Percent Excess Air. Calculate the per-
cent excess air (if applicable), by substitut-
ing the appropriate values of percent O,,
CO, and N, (obtained from Section 4.1.3  or
4.2.4) into Equation 3-1.
    Title 40—Protection of Environment
        r
        L
                             100
0.264 %N2( %0,-0.5 %CO)

                    Equation 3-1
   NOTE: The equation above  assumes that
 ambient air is used as the source of O, and
 that the fuel does not contain  appreciable
 amounts of N, (as do coke oven or blast fur-
 nace gases). For those cases when apprecia-
 ble amounts of N, are present (coal, oil, and
 natural gas  do  not  contain  appreciable
 amounts of N,) or when oxygen  enrichment
 is  used, alternate methods, subject to ap-
 proval of the Administrator, are required.
   6.3  Dry Molecular Weight.  Use Equation
 3-2 to calculate the dry molecular weight of
 the stack gas
                         0.280(%N,+%CO)
                              Equation 3-2
  NOTE: The above equation does not consid-
 er  argon in  air (about 0.9 percent,  molecu-
 lars weight  of 37.7). A  negative  error  of
 about 0.4 percent is  introduced. The tester
 may  opt to  include  argon in the analysis
 using procedures subject  to approval of the
 Administrator.

 7. Bibliography

  1. Altshuller, A. P. Storage of Gases and
 Vapors in Plastic  Bags. International Jour-
 nal of  Air  and  Water  Pollution.  6.-75-81
 1963.
  2. Conner, William D. and J. S. Nader. Air
 Sampling with Plastice Bags. Journal of the
 American Industrial  Hygiene Association
 25.-291-297. 1964.
  3. Burrell  Manual for Gas Ana)ysts, Sev-
 enth  edition.  Burrell Corporation,  2223
 Fifth Avenue, Pittsburgh,  Pa. 15219. 1951.
  4. Mitchell, W. J. and M. R. Midgett. Field
 Reliability of the Orsat Analyzer. Journal
of Air Pollution Control Association  25:491-
495. May 1976.
  5. Shigehara, R. T., R.  M. Neulicht,  and
W. S. Smith. Validating Orsat Analysis Data
from  Fossil  Fuel-Fired Units.  Stack Sam-
pling News. «2):21-26. August  1976
                                        139

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App. A
Title 40—Protection of Environment
                        METHOD 7—DETERMINATION OP NITROGEN
                      OXIDE EMISSIONS PROM STATIONARY SOURCES

                      1. Principle and Applicability
                        1.1  Principle.  A grab sample is collected
                      in an evacuated flask containing a dilute
                      sulfuric acid-hydrogen peroxide  absorbing
                      solution, and the nitrogen oxides, except ni-
                      trous oxide, are  measured colorimeterically
                      using the  phenoldisulfonic acid (PDS) pro-
                      cedure.
                        1.2  Applicability. This method is applica-
                      ble to the measurement  of nitrogen oxides
                      emitted from stationary sources. The range
                      of the method has been determined to be  2
                      to 400  milligrams  NO,  (as NO,) per dry
                      standard cubic  meter, without having to
                      dilute the sample.
                      2. Apparatus
                        2.1  Sampling (see Figure 7-1). Other grab
                      sampling systems or_equipment, capable of
                      measuring sample  volume to within  ±2.0
                      percent and collecting a sufficient sample
                      volume to allow analytical reproducibility to
                      within ±5  percent, will  be considered ac-
                      ceptable alternatives, subject to approval of
                      the Administrator. U.S. Environmental Pro-
                      tection Agency. The following equipment is
                      used in sampling:
                        2.1.1  Probe. Borosilicate glass tubing, suf-
                      ficiently heated  to prevent water condensa-
                      tion and equipped with an in-stack or out-
                      stack filter to  remove particulate matter (a
                      plug of glass  wool is  satisfactory for this
                      purpose). Stainless steel  or Teflon 3 tubing
                      may also be used for  the probe. Heating is
                      not  necessary if  the probe  remains dry
                      during the purging period.
                                         140

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 Chapter I—Environmental Protection Agency
                                            APP.A
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                                  141

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 Chapter I—Environmental Protection Agency
                                  App.A
  2.1.2  Collection Flask. Two-liter borosili-
 cate, round bottom flask, with short neck
 and 24/40 standard taper opening, protected
 against implosion or breakage.
  2.1.3  Flask Valve. T-bore stopcock con-
 nected to a 24/40 standard taper joint.
  2.1.4  Temperature Gauge. Dial-type ther-
 mometer, or other temperature gauge, capa-
 ble of measuring 1* C (2° F) intervals from
 -5 to 50" C (25 to 125' F).
  2.1.5  Vacuum Line.  Tubing  capable of
 withstanding a vacuum of 75 mm Hg (3 in.
 Hg) absolute pressure, with "T" connection
 and T-bore stopcock.
  2.1.6  Vacuum Gauge. U-tube manometer,
 1 meter (36 in.), with 1-mm (0.1-in.) divi-
 sions, or other gauge capable of measuring
 pressure to within  ±2.5 mm Hg (0.10  in.
 Hg).
  2.1.7  Pump.  Capable  of  evacuating the
 collection flask to a pressure equal to or less
 than 75 mm Hg (3 in. Hg) absolute.
  2.1.8  Squeeze Bulb. One-way.
  2.1.9  Volumetric Pipette. 25 ml.
  2.1.10  Stopcock   and   Ground   Joint
 Grease. A  high-vacuum,  high-temperature
 chlorofluorocarbon grease is required. Halo-
 carbon 25-5S has been found to be effective.
  2.1.11  Barometer. Mercury,  aneroid,  or
 other barometer capable of measuring  at-
 mospheric pressure to  within  2.5 mm Hg"
 (0.1  in.  Hg). In many cases, the barometric
 reading may be obtained from a nearby na-
 tional weather service station, in which case
 the  station  value  (which is  the absolute
 barometric pressure) shall be requested and
 an adjustment for elevation differences be-
 tween the  weather station  and  sampling
 point shall be applied at a rate of minus 2.5
 mm  Hg (0.1  in. Hg) per 30 m (lO'O ft) eleva-
 tion increase, or vice versa for elevation de-
 crease.
  2.2  Sample  Recovery.  The  following
 equipment is required for sample recovery:
  2.2.1  Graduated Cylinder. 50  ml with 1-
 ml divisions.
  2.2.2  Storage Containers.  Leak-free poly-
 ethylene bottles.
  2.2.3  Wash Bottle. Polyethylene or glass.
  2.2.4  Glass Stirring Rod.
  2.2.5  Test  Paper for Indicating pH. To
 cover the pH range of 7 to 14.
  2.3  Analysis. For the analysis, the follow-
 ing equipment is needed:
  2.3.1  Volumetric Pipettes. Two 1 ml, two
 2 ml, one 3 ml, one 4 ml, two 10 ml, and one
 25 ml for each sample and standard.
  2.3.2  Porcelain Evaporating Dishes. 175-
 to 250-ml capacity with lip for pouring, one
 for  each sample  and  each  standard. The
 Coors No. 45006 (shallow-form, 195 ml) has
been found to be satisfactory. Alternatively,
polymethyl  pentene  beakers  (Nalge No.
 1203, 150 ml), or glass beakers (150 ml) may
be used. When glass beakers are used, etch-
ing of the beakers may cause solid matter to
be present in the analytical  step; the solids
 should be removed by filtration (see Section
 4.3).
  2.3.3  Steam   Bath.    Low-temperature
 ovens or  thermostatically controlled hot
 plates kept below 70° C (160° F) are accept-
 able alternatives.
  2.3.4  Dropping Pipette or Dropper. Three
 required.
  2.3.5  Polyethylene  Policeman.  One  for
 each sample and each standard.
  2.3.6  Graduated Cylinder. 100 ml with 1-
 ml divisions.
  2.3.7  Volumetric Flasks. 50  ml (one  for
 each sample  and  each  standard),  100  ml
 (one  for each sample and each  standard,
 and one for the working standard KNO3 so-
 lution), and 1000 ml (one).
  2.3.8  Spectrophotometer. To measure  ab-
 sorbance at 410 nm.
  2.3.9  Graduated Pipette. 10  ml with 0.1-
 ml divisions.
  2.3.10  Test Paper for Indicating  pH.  To
 cover the pH range of 7 to 14.
  2.3.11  Analytical Balance. To measure to
 within 0.1 mg.
 3. Reagents
  Unless otherwise indicated, it is intended
 that  all  reagents conform to the  specifica-
 tions established by the Committee on Ana-
 lytical Reagents of the American  Chemical
 Society,  where such specifications are avail-
 able;  otherwise,  use the best available grade.
  3.1  Sampling. To prepare the absorbing
 solution, cautiously add 2.8 ml  concentrated
 HiSO, to 1 liter  of deionized, distilled water.
 Mix well and add 6 ml of 3 percent hydro-
 gen peroxide, freshly prepared  from 30 per-
 cent  hydrogen  peroxide  solution. The  ab-
 sorbing  solution should be used- within 1
 week of its preparation. Do not expose  to
 extreme heat or direct sunlight.
  3.2  Sample Recovery. Two  reagents are
 required for sample recovery:
  3.2.1  Sodium  Hydroxide (1JV). Dissolve 40
 g NaOH in deionized,  distilled wacer and
 dilute to 1 liter.
  3.2.2  Water. Deionized, distilled to con-
 form to ASTM specification D1193-74, Type
 3. At the option of the analyst, the KMNO,
 test  for  oxidizable organic matter may  be
 omitted when high concentrations of organ-
 ic matter are not expected to be present.
  3.3  Analysis. For the analysis, the follow-
 ing reagents are  required:
  3.3.1  Fuming  Sulfuric Acid.  15 to 18 per-
 cent  by  weight  free   sulfur  trioxide.
 HANDLE WITH CAUTION.
  3.3.2  Phenol.  White solid.
  3.3.3  Sulfuric Acid. Concentrated, 95 per-
cent minimum assay. HANDLE  WITH CAU-
TION.
  3.3.4  Potassium Nitrate. Dried at 105 to
 110°  C (220 to 230° F) for a minimum of 2
hours just  prior to preparation of standard
solution.
                                        142

-------
App. A
   title 40—Protection of Environment
  3.3.5  Standard KNO, Solution. Dissolve
exactly 2.198  g of  dried potassium  nitrate
(KNO3)  in  deionized, distilled  water  and
dilute  to 1 liter with deionized, distilled
water in a 1,000-ml volumetric flask.
  3.3.6  Working Standard KNO,  Solution.
Dilute 10 ml of the standard solution to 100
ml with deionized distilled water.  One  mil-
liter of  the working  standard  solution  is
equivalent to 100 jig nitrogen dioxide (NO,).
  3.3.7  Water. Deionized, distilled  as in Sec-
tion 3.2.2.
  3.3.8  Phenoldisulfonic Acid Solution. Dis-
solve  25 g of  pure  white phenol in  150 ml
concentrated sulfuric acid on a steam bath.
Cool,  add 75 ml fuming sulfuric  acid,  and
heat at 100° C (212° P) for 2 hours. Store in
a dark, stoppered bottle.
4. Procedures
  4.1  Sampling.
  4.1.1  Pipette 25 ml of absorbing solution
into a sample flask,  retaining-a sufficient
quantity for use in preparing the calibration
standards.  Insert the flask  valve stopper
into the flask  with the valve in the "purge"
position. Assemble  the  sampling  train as
shown in Figure 7-1 and place the probe at
the sampling point. Make sure that all fit-
ings are tight and leak-free, and that all
ground  glass  joints  have  been  properly
greased with a high-vacuum,  high-tempera""
ture   chlorofluorocarbon-based   stopcock
grease. Turn the flask valve and the pump
valve  to their "evacuate" positions.  Evacu-
ate the flask to 75 mm Hg (3 in. Hg) abso-
lute pressure,  or less. Evacuation to  a pres-
sure approaching  the  vapor pressure  of
water at the existing temperature is desir-
able. Turn the pump valve to its "vent" po-
sition and turn the off the pump. Check for
leakage by  observing the  manometer  for
any  pressure  fluctuation.  (Any  variation
greater than 10 mm Hg  (0.4  in.  Hg) over a
period of 1 minute is not acceptable, and the
flask  is not to  be  used until the leakage
problem is corrected. Pressure in the flask is
not to exceed 75 mm Hg (3 in. Hg) absolute
at the time sampling is commenced.) Record
the volume  of the flask and valve (Vf),  the
flask temperature (Ti), and the  barometric
pressure. Turn the flask valve counterclock-
wise to its "purge" position and do  the same
with the pump valve. Purge the probe and
the vacuum tube using the squeeze bulb. If
condensation occurs in the  probe and  the
flask valve  area, heat the probe and purge
until  the condensation  disappears. Next,
turn the pump valve to its "vent" position.
Turn the flask valve clockwise to its "evacu-
ate" position and record the  difference in
the mercury levels  in the manometer. The
absolute internal pressure in the flask (Vj) is
equal to the  barometric pressure less  the
manometer  reading. Immediately  turn  the
flask  valve  to the  "sample"  position and
permit the gas to enter the flask until pres-
sures in the flask and sample line (i.e., duct.
stack) are equal. This  will usually  require
about 15 seconds; a longer period indicates a
"plug" in the probe, which must be correct-
ed before sampling is continued. After col-
lecting the sample, turn the flask valve to
its "purge" position and disconnect the flask
from the sampling train. Shake the flask for
at least 5 minutes.
  4.1.2  If  the  gas  being  sampled contains
insufficient oxygen for the conversion of
NO  to Nd (e.g., an applicable subpart of
the standard may require taking a sample of
a calibration gas mixture of NO in N,), then
oxygen shall be introduced into the flask to
permit this conversion.  Oxygen may be in-
troduced  into  the  flask  by one of three
methods;  (1) Before evacuating the sam-
pling flask, flush with pure cylinder oxygen,
then evacuate flask to 75 mm Hg (3  in. Hg)
absolute  pressure  or  less;  or (2)  inject
oxygen into the flask after sampling; or (3)
terminate sampling with a  minimum of 50
mm  Hg (2 in. Hg) vacuum remaining in the
flask, record this final  pressure, and then
vent the flask  to the atmosphere until the
flask pressure is almost  equal to atmospher-
ic pressure.
  4.2 Sample Recovery. Let  the flask set
for a minimum of 16 hours and then shake
the  contents for 2 minutes. Connect the
flask to a mercury filled U-tube manometer.
Open the valve from the flask to the mano-
meter and record  the flask temperature"(2>),
the barometric pressure, and the difference
between  the mercury levels in the  mano-
meter. The absolute internal pressure in the
flask (Pf) is the barometric pressure less the
manometer  reading. Transfer the contents
of the  flask  to  a  leak-free  polyethylene
bottle. Rinse the  flask twice with 5-ml por-
tions of deionized,  distilled water and add
the rinse water to the bottle. Adjust  the pH
to between 9 and 12 by adding sodium hy-
droxide (1 N), drop wise  (about 25  to 35
drops). Check the pH bv dipping a stirring
rod into the solution and then touching the
rod to the pH  test paper. Remove as little
material  as possible during  this step. Mark
the  height of the liquid level so that the
container can be  checked for leakage after
transport. Label  the container to  clearly
identify its contents. Seal the container for
shipping.
  4.3  Analysis. Note the level of the liquid
in container and confirm  whether  or not
any  sample  was lost during shipment; note
this on the analytical data sheet. If a notice-
able  amount of leakage  has occurred, either
void  the sample or  use  methods, subject to
the approval of the Administrator,  to cor-
rect  the final results. Immediately prior to
analysis,  transfer the contents of the ship-
ping container  to a 50-ml volumetric flask.
and rinse the container  twice with 5-ml por-
tions of deionized, distilled  water. Add the
                                       143

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Chapter I—Environmental Protection Agency

rinse water to  the flask and dilute to the
mark with  deionized,  distilled  water;  mix
thoroughly. Pipette a 25-ml aliquot into the
procelain evaporating  dish. Return  any
unused portion of the sample to  the  poly-
ethylene storage bottle. Evaporate the 25-
ml aliquot to dryness on a steam  bath and
allow to cool.  Add  2 ml  phenoldisulfonic
acid solution to the dried  residue and trit-
urate thoroughly  with a polyethylene po-
liceman. Make sure the solution  contacts all
the residue. Add  1  ml deionized. distilled
water and four drops of concentrated sulfu-
ric acid. Heat the solution  on a  steam bath
for 3 minutes with occasional stirring. Allow
:he solution to cool, add  20 ml deionized,
distilled water, mix well by stirring, and add
concentrated ammonium hydroxide, drop-
wise, with constant stirring, until  the pH is
10 (as  determined by pH paper). If the
sample contains solids, these must be  re-
moved by filtration (centrifugation is an ac-
ceptable alternative, subject to the approval
of the  Administrator),  as  follows:  filter
through Whatman No. 41 filter paper into a
100-ml volumetric flask; rinse the  evaporat-
ing dish with three 5-ml portions of deion-
ized. distilled water; filter these three rinses.
Wash  the  filter with  at least three 15-ml
portions of deionized, distilled  water. Add-
the filter washings to the contents of the
volumetric flask and dilute  to the mark with
deionized,  distilled  water.  If  solids are
absent, the solution can be  transferred di-
rectly to the 100-ml volumetric flask and di-
luted to the mark with  deionized, distilled
•*iter. Mix  the contents of the flask  thor-
oughly, and measure the absorbance at the
optimum wavelength used for the standards
 Section 5.2.1), using the blank solution as a
zero reference. Dilute the sample and the
blank with equal volumes  of deionized, dis-
tilled water if  the absorbance  exceeds A,,
the absorbance of the 400  /ig NO, standard
 see Section 5.2.2).
                                 App. A
5. Calibration
  5.1 Flask Volume. The volume of the col-
lection  flask-flask valve combination  must
be known prior to sampling. Assemble the
flask and flask valve and fill with water, to
the stopcock. Measure the volume  of water
'.o =10  ml. Record this volume on the flask.
  5.2 Spectrophotometer Calibration.
  5.2.1  Optimum  Wavelength  Determina-
tion. Calibrate the wavelength scale of the
^pectrophotometer every  6 months. The
•alteration may be accomplished by using
an energy source with an intense line emis-
-.on such as a mercury lamp, or by using a
•cries of glass filters spanning the measur-
•ng range  of the  Spectrophotometer.  Cali-
bration materials are available commercially
and from the National Bureau of Standards.
Specific details on the use of such materials
>hould  be supplied by the  vendor; general
..".formation  about calibration   techniques
can  be obtained  from  general reference
books  on  analytical chemistry. The wave-
length scale of the Spectrophotometer must
read correctly within ± 5 nm al all calibra-
tion points;  otherwise,  the  specrophoto-
meter  shall be  repaired  and  recalibrated.
Once the  wavelength scale of the  Spectro-
photometer is in proper calibration, use 410
nm as the optimum wavelength for the mea-
surement  of  the absorbance of the stand-
ards and samples.
  Alternatively, a scanning procedure may
be employed to determine the proper meas-
uring  wavelength.  If the  instrument is a
double-beam  Spectrophotometer, scan  the
spectrum  between 400 and 415 nm using a
200 fig NO, standard solution in the sample
cell  and a blank solution  in the reference
cell. If a peak does not occur, the  Spectro-
photometer is probably malfunctioning  and
should be repaired. When a peak is obtained
within the 400 to 415 nm  range, the wave-
length at which this peak occurs shall be
the  optimum  wavelength for the measure-
ment of absorbance of both the standards
and the samples. For a single-beam Spectro-
photometer, follow the scanning procedure
described  above, except that the blank  and
standard  solutions  shall be scanned sepa-
rately. The optimum wavelength shall be
the wavelength at which the maximum dif-
ference in absorbance between the standard
and the blank occurs.
  5.2.2  Determination   of  Spectrophoto-
meter  Calibration Factor Ke. Add 0.0 ml, 2
ml, 4 ml, 6 ml., and 8 ml of the KNO, work-
ing standard  solution (1 ml=100 ps NO,) to
a series of five 50-ml volumetric flasks. To
each flask, add 25 ml of absorbing solution,
10 ml deionized, distilled water, and sodium
hydroxide (1  N) dropwise until the pH is be-
tween  9 and 12 (about 25 to 35 drops each).
Dilute to  the  mark with deionized. distilled
water. Mix thoroughly and pipette a 25-ml
aliquot of e?ch solution into a separate  por-
celain  evaporating dish. Beginning with the
evaporation step, follow the analysis proce-
dure of Section 4.3 until  the  solution  has
been transferred to the  100 ml volumetric
flask and diluted to the mark. Measure the
absorbance of each solution,  at the opti-
mum wavelength, as  determined in Section
5.2.1. This calibration procedure must be re-
peated on each day that samples are ana-
lyzed.  Calculate the Spectrophotometer cali-
bration factor as follows:
                         Equation 7-1
                                       144

-------
 App. A
    Title 40—Protection of Environment
 where:
 JTC=Calibration factor
 4,=Absorbance of the  100-jig NO2 standard
 4j=Absorbance of the  200-jig NO2 standard
 .43=Absorbance of the  300-jig NO2 standard
 <4<=Absorbance of the  400-^g NO2 standard
   5.3  Barometer. Calibrate against a mer-
 cury barometer.
   5.4  Temperature Gauge. Calibrate  dial
 thermometers   against    mercury-in-glass
 thermometers.
   5.5  Vacuum Gauge. Calibrate mechanical
 gauges,  if used, against  a mercury  mano-
 meter such as that specified in 2.1.6.
   5.6  Analytical Balance. Calibrate against
 standard weights.
 6. Calculations
   Carry  out the calculations,  retaining  at
 least one extra decimal figure beyond that
 of the acquired data. Round  off figures
 after final calculations.
  6.1' Nomenclature.
 .A=Absorbance of sample.
 C= Concentration of NO*  as NO2> dry basis,
    corrected  to  standard conditions, mg/
    dscm (Ib/dscf).   '
 ^Dilution factor (i.e.,  25/5, 25/10, etc., re^..
    quired  only  if sample  dilution  was
    needed to reduce  the absorbance into
    the range of calibration).
 .K:=Spectrophotometer calibration factor.
 m=Mass of NOr as NO2  in gas sample, pig.
 .P,=Final absolute pressure of flask, mm Hg
    (in. Hg}.
 Pi=Initial  absolute pressure of flask, mm
    Hg (in. Hg).
 •P,,= Final absolute temperature of flask, °K
   CR).
 Ti=Initial absolute temperature of flask, °K
   (°R>.
 r,,rt=Standard absolute  temperature 293° K
   (528° R)
 V«r=Sample volume at  standard conditions
   (dry basis), ml.
 Vf=Volume of flask and valve, ml.
 Va=Volume of absorbing soluton, 25 ml.
2 = 50/25, the aliquot factor. (If other than a
   25-ml aliquot  was used for analysis, the
   corresponding factor must be substitut-
   ed).
6.2 Sample volume, dry basis, corrected  to
   standard conditions.
    A"i = 0.3858
                mm Hg
  for metric units
       = 17.64 r
               in. Hg
for English units
 6.3 Total jig NO: per sample.
                             Equation 7-3
  NOTE: If other than a 25-ml aliquot is used
 for analysis, the factor 2 must be replaced
 by a corresponding factor.
  6.4  Sample concentration, dry basis, cor-
 rected to standard conditions.
                            Equation 7-4
where:
    =3    ,-,- for metric units
      0.243 X 10-5     -  for English units
                           Equation 7-2
7. Bibliography
  1. Standard Methods of Chemical Analysis
6th ed. New York, D. Van Nostrand Co., Inc.
1962. Vol. 1, p. 329-330.
  2. Standard Method of Test for Oxides of
Nitrogen in Gaseous  Combustion Products
(Phenoldisulfonic Acid Procedure). In: 1968
Book of ASTM Standards, Part 26. Philade-
phia. Pa. 1968. ASTM Designation D-1608-
60, p. 725-729.
  3. Jacob, M. B. The Chemical Analysis of
Air Pollutants. New York. Interscience Pub-
lisher, Inc. 1960. Vol. 10, p. 351-356.
  4. Beatty, R. L., L.  B. Berger, and H. H.
Schrenk. Determination of Oxides of Nitro-
gen by the Phenoldisulfonic Acid Method.
Bureau of Mines, U.S. Dept. of Interior. R.I.
3687. February 1943.
                                        145

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Chapter I—Environmental Protection Agency
APP.A
                       5. Hamil, H. F.  and D. E. Camann. Col-
                     laborative  Study of method for the Deter-
                     mination of Nitrogen  Oxide Emissions from
                     Stationary Sources (Fossil Fuel-Fired Steam
                     Generators). Southwest Research Institute
                     report   for   Environmental   Protection
                     Agency. Research Triangle Park, N.C. Octo-
                     ber 5, 1973.
                       6. Hamil, H. F. and R. E. Thomas. Collabo-
                     rative Study of Method for the Determina-
                     tion of Nitrogen Oxide Emissions from Sta-
                     tionary Sources (Nitric Acid Plants). South-
                     west Research Institute report for Environ-
                     mental Protection  Agency. Research Trian-
                     gle Park, N.C. May 8, 1974.
                                      146

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App. A
Title 40—Protection of Environment
                                  147

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Chapter I—Environmental Protection Ageney
                                 App. B
PERFORMANCE   SPECIFICATION  2—PERFORM-
  ANCE  SPECIFICATIONS  AND  SPECIFICATION
  TEST  PROCEDURES FOR  MONITORS OF SO3
  AND NO. FROM STATIONARY SOURCES

  1. Principle and Applicability.
  1.1 Principle. The concentration of sulfur
dioxide or  oxides of nitrogen pollutants in
stack emissions is measured  by a continu-
ously   operating  emission  measurement
system. Concurrent with operation of  the
continuous monitoring system, the pollut-
ant concentrations are also measured with
reference methods (Appendix A). An aver-
age of  the continuous  monitoring system
data is computed for each reference method
testing  period and compared to  determine
the  relative  accuracy of the continuous
monitoring system. Other tests of the con-
tinuous monitoring  system-  are  also  per-
formed to determine calibration error, drift.
and response characteristics of the system. —
  1.2 Applicability. This performance speci-
fication is  applicable  to  evaluation of con-
tinuous monitoring systems  for measure-
ment of nitrogen oxides or sulfur dioxide
pollutants.  These specifications contain test
procedures, installation  requirements, and
data computation procedures for evaluating
the acceptability of the continuous monitor-
ing systems.
  2. Apparatus.
  2.1 Calibration Gas Mixtures. Mixtures of
known concentrations of pollutant gas in a
diluent gas shall be prepared. The pollutant
gas shall be sulfur dioxide or the appropri-
ate oxide(s) of nitrogen specified  by para-
graph  6 and  within subparts. For sulfur
dioxide gas mixtures, the diluent gas may be
air or  nitrogen. For nitric oxide (NO)  gas
mixtures, the  diluent gas shall be oxygen-
free (<10 ppm) nitrogen, and for  nitrogen
dioxide (NO,)  gas mixtures the diluent  gas
shall be air. Concentrations of approximate-
ly 50 percent and 90 percent of span are re-
quired. The 90 percent gas mixture is used
to set and to check the span and is referred
to as the span gas.
  2.2 Zero Gas. A gas certified by the manu-
facturer  to contain  less than 1 ppm of the
pollutant gas or ambient air may be used.
  2.3 Equipment  for measurement of the
pollutant gas concentration using the refer-
                                        143

-------
 App. B
    Title 40—Protection of Environment
 ence method  specified in  the applicable
 standard.
   2.4 Data Recorder. Analog chart recorder
 or other suitable device with input voltage
 range  compatible  with  analyzer  system
 output.  The  resolution of  the recorder's
 data output shall be sufficient to allow com-
 pletion of the test procedures within  this
 specification.
   2.5 Continuous monitoring system for SO,
 or NO, pollutants as applicable.
   3. Definitions.
   3.1 Continuous Monitoring System. The
 total equipment required for the determina-
 tion of a pollutant gas concentration in a
 source effluent. Continuous monitoring sys-
 tems consist of major subsystems as follows:
   3.1-.1 Sampling Interface. That portion of
 an extractive continuous monitoring system
 that performs one or more of the following
 operations: acquisition, transportation,  and
 conditioning of a sample fo the source efflu-
 ent or that portion of an in-situ continuous
 monitoring system that protects the analyz-
 er from the effluent.
   3.1.2 Analyzer. That portion of the con-
 tinuous monitoring system which senses the
 pollutant gas and generates a signal output
 that is a function of the pollutant concen-
 tration.
  3.1.3 Data Recorder. That  portion of the-
 continuous monitoring system that provides
 a  permanent record of the output signal in
 terms of concentration units.
  3.2- Span. The value of pollutant concen-
 tration at which the continuous monitoring
 system is set to produce the maximum data
 display output. The span shall be set at the
 concentration  specified in each  applicable
 subpart.
  3.3 Accuracy (Relative). The degree of cor-
 rectness  with  which the continuous moni-
 toring system yields the value of gas concen-
 tration  of a  sample relative to  the value
 given by a defined reference method. This
 accuracy is  expressed  in  terms of error,
 which is the difference between the paired
 concentration measurements expressed as a
 percentage of the mean reference value.
  3.4 Calibration Error. The  difference be-
 tween the pollutant concentration indicated
by the continuous  monitoring  system and
the  known concentration  of the test  gas
mixture.
  3.5 Zero Drift. The change in the continu-
ous monitoring system output over a stated
period  of time  of normal continuous oper-
ation when the pollutant concentration  at
the time for the measurements is zero.
  3.6 Calibration  Drift. The change in the
continuous monitoring system output over a
stated time period of normal continuous op-
erations  when the pollutant  concentration
at the time of the measurements is the same
known upscale value.
  3.7 Response  Time.  The  time interval
from a step change in pollutant concentra-
 tion at the input to the continuous monitor-
 ing system to the time at which 95 percent
 of the corresponding final value is reached
 as displayed on the continuous monitoring
 system data recorder.
   3.8 Operational Period. A minimum period
 of time over which a measurement system is
 expected to operate within certain perform-
 ance  specifications  without  unscheduled
 maintenance, repair, or adjustment.
   3.9 Stratification. A  condition  identified
 by a difference in excess of 10 percent be-
 tween the average concentration in the duct
 or stack and the concentration at any point
 more than 1.0 meter from the duct or stack
 wall.
   4.  Installation  Specifications.  Pollutant
 continuous monitoring  systems  (SO, and
 NO,) shall be installed at a sampling loca-
 tion  where  measurements  can  be  made
 which  are directly representative (4.1), or
 which can be corrected so as  to  be repre-
 sentative (4.2)  of  the total emissions from
 the affected facility. Conformance with this
 requirement  shall  be accomplished as fol-
 lows:
   4.1  Effluent gases may be assumed  to be
 nonstratified if a sampling location eight or
 more stack diameters (equivalent diameters)
 downstream of any air in-leakage is selected.
 This assumption and  data correction proce-
 dures under paragraph 4.2.1 may not be ap-
 plied to sampling  locations upstream of an
 air preheater in a stream generating facility
 under Subpart D of this part. For sampling
 locations where effluent  gases are  either
 demonstrated (4.3) or may be assumed to be
 nonstratified (eight diameters), a point (ex-
 tractive systems) or path (in-situ systems) of
 average concentration may be monitored.
  4.2 For sampling  locations where effluent
 gases cannot be assumed to be nonstratified
 (less  than eight diameters) or have  been
 shown under paragraph 4.3 to be stratified,
 results obtained must be consistently repre-
 sentative (e.g. a point of average concentra-
 tion may shift with load  changes) or the
 data generated by sampling at  a point (ex-
 tractive  systems) or across a path  (in-situ
 systems) must be corrected (4.2.1 and 4.2.2)
 so as to be representative of the total emis-
 sions  from the affected facility. Conform-
 ance with  this requirement may be accom-
 plished in either of the following ways:
  4.2.1 Installation  of a diluent continuous
 monitoring system (O, or CO, as applicable)
 in accordance with the procedures under
 paragraph  4.2 of Performance Specification
 3 of this appendix. If the pollutant and di-
 luent monitoring systems are  not  of  the
same type  (both extractive or both in-situ),
 the extractive system must use a multipoint
probe.
  4.2.2 Installation  of extractive pollutant
monitoring systems using  multipoint  sam-
pling probes or in-situ pollutant monitoring
                                        149

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Chapter I—Environmental Protection Agency
                                 App. B
systems  that  sample  or view  emissions
which are consistently representative of the
total emissions for the entire cross section.
The Administrator may require data to be
submitted  to  demonstrate that  the  emis-
sions  sampled or viewed  are consistently
representative  for several typical facility
process operating conditions.
  4.3 The owner or operator may perform a
traverse to characterize any stratification of
effluent gases that might exist in a stack or
duct.  If  no stratification  is  present, sam-
pling procedures under paragraph 4.1 may
be applied  even though the eight diameter
criteria is not met.
  4.4 When single point sampling probes for
extractive systems are installed within the
stack or  duct under  paragraphs 4.1 and
4.2.1, the sample may not be extracted at
any point less than 1.0 meter from the stack
or duct wall. Multipoint sampling probes in-
stalled under paragraph 4.2.2 may be locat-
ed at any points necessary to obtain consist-
ently representative samples.
  5.  Continuous  Monitoring  System  Per-
formance Specifications.
  The continuous monitoring system shall
meet the performance  specifications  in
Table 2-1 to be considered acceptable under
this method.
                       TABLE 2-1—PERFORMANCE SPECIFICATIONS
Parameter
1, Accuracy' 	
Z. Calibration error1 	
3, Zero drift (2 h) ' 	 	
4. Zero drift (24 h) ' 	
5 Calibration drift (2 h) '
6. Calibration drift (24 h) > 	
7, Response time.. 	 « 	
8. Operational period 	

Specification
<20 pet of the mean value of the reference method test data.
< 5 pet of each (50 pet, 90 pet) calibration gas mixture value.
Do.
Do
2.5 pet of span.
15 min maximum.
168 h minimum.

  ' Expressed as sum of absolute mean value plus 95 pet confidence interval of a series of tests.
  6. Performance Specification Test Proce-
dures. The following test procedures shall
be used to determine conformance with the
requirements of paragraph 5. For NO, ana-
lyzers that oxidize nitric oxide (NO) to ni-
trogen dioxide (NO,),the response time test
under paragraph 6.3  of this method shall be
performed using nitric oxide (NO) span gas.
Other'tests for NO,  continuous monitoring
systems under paragraphs 6.1  and 6.2 and
all tests for sulfur dioxide systems shall be
performed  using the  pollutant  span  gas
specified by each subpart.
  6.1 Calibration Error Test Procedure. Set
up and calibrate the complete continuous
monitoring system according to the manu-
facturer's written instructions. This may be
accomplished either  in the laboratory or in
the field.
  6.1.1  Calibration Gas Analyses. Triplicate
analyses of the  gas  mixtures  shall be per-
formed within two weeks prior to use using
Reference Methods 6 for SO3 and 7 for NO,.
Analyze each calibration gas mixture (50%,
90%) and record the  results on the example
sheet shown in Figure 2-1. Each sample test
result must be within 20 percent of the aver-
aged result or the tests shall be repeated.
This step may be omitted for non-extractive
monitors  where dynamic calibration  gas
mixtures are not used (6.1.2).
  6.1.'2  Calibration  Error Test Procedure.
Make a total of 15 nonconsecutive  meas-
urements by alternately using zero gas and
each calibration gas  mixture concentration
(e.g., 0%, 50%, 0%, 90%, 50%, 90%, 50%, 0%,
etc.). For nonextractive continuous monitor-
ing systems, this test procedure may be per-
formed by using two or more calibration gas
cells whose  concentrations are certified by
the manufacturer to be functionally equiva-
lent to these gas concentrations.  Convert
the continuous monitoring system output
readings to  ppm and  record the  results on
the example sheet shown in Figure 2-2.
  6.2  Field  Test  for   Accuracy (Relative),
Zero  Drift,  and  Calibration Drift. Install
and  operate  the  continuous monitoring
system in accordance  with the manufactur-
er's written instructions and drawings as fol-
lows:
  6.2.1 Conditioning Period. Offset the zero
setting at least 10  percent of the  span so
that negative zero drift  can be quantified.
Operate the  system for an initial 168-hour
conditioning  period  in  normal  operating
manner.
  6.2.2 Operational Test Period. Operate the
continuous monitoring system for an addi-
tional  168-hour  period retaining  the  zero
offset. The system shall monitor the source
effluent  at  all times except when  being
zeroed, calibrated, or backpurged.
  6.2.2.1 Field Test for Accuracy (Relative).
For continuous monitoring systems employ-
ing extractive sampling, the probe tip for
the continuous monitoring system and the
probe tip for the Reference Method  sam-
pling  train should be  placed at adjacent lo-
cations  in  the duct.  For  NO, continuous
                                        150

-------
App. B
   Title 40—Protection of Environment
monitoring systems, make 27 NO, concen-
tration  measurements, divided into  nine
sets, using the applicable reference method.
No more than one set of tests, consisting of
three individual measurements, shall be per-
formed  in any  one  hour. All individual
measurements of  each set  shall  be per-
formed  concurrently,  or  within  a three-
minute  interval  and the  results averaged.
For  SOa  continuous  monitoring  systems,
make nine SO* concentration measurements
using the applicable reference method. No
more than one measurement  shall be per-
formed  in any one hour. Record the  refer-
ence method test  data and the continuous
monitoring system concentrations on  the
example data sheet shown in Figure 2-3.
  6.2.2.2 Field Test for Zero Drift and Cali-
bration  Drift. For  extractive systems, deter-
mine the values given by zero and  span gas
pollutant  concentrations at two-hour  inter-
vals  until 15 sets of data are obtained. For
nonextractive  measurement  systems,  the
zero value may be determined by mechani-
cally producing a  zero condition that pro-
vides -a system check of the analyzer  inter-
nal mirrors and all electronic circuitry in-
cluding  the radiation  source  and  detector
assembly or by inserting three or more cali-.
oration  gas  cells  and  computing  the zero--
point from the  upscale measurements. If
this  latter technique  is used,  a  graph(s)
must be retained by the owner or  operator
for each measurement system that shows
the relationship between the upscale meas-
urements  and the  zero point. The span of
the system shall be checked by using a cali-
bration gas cell certified by the manufactur-
er to be functionally equivalent to 50 per-
cent of span concentration. Record the zero
and  span  measurements (or the computed
zero drift) on the example  data sheet shown
in Figure 2-4. The two-hour  periods  over
which measurements  are  conducted  need
not be consecutive but  may not overlap. All
measurements required under  this  para-
graph may be conducted concurrent  with
tests under paragraph 6.2.2.1.
  6.2.2.3 Adjustments. Zero and calibration
corrections and  adjustments  are  allowed
only at 24-hour intervals or at such shorter
intervals  as  the  manufacturer's   written
instructions specify. Automatic  corrections
made by the  measurement system without
operator intervention or initiation are allow-
able at any time. During the entire  168-hour
operational test period, record  on the exam-
ple sheet shown in Figure 2-5 the values
given by zero and span gas pollutant con-
centrations before and after adjustment at
24-hour intervals.
  8.3 Field Test for Response Time.
  6.3.1 Scope of Test.  Use the  entire con-
tinuous  monitoring system as installed, in-
cluding sample transport lines if used. Flow
rates, line diameters, pumping rates, pres-
sures (do not allow the pressurized calibra-
tion gas  to change the normal operating
pressure in the sample line), etc., shall be at
the nominal values for normal operation as
specified  in  the  manufacturer's  written
instructions.  If the  analyzer  is  used  to
sample  more   than  one  pollutant  source
(stack),  repeat  this test for each sampling
point.
  6.3.2 Response Time Test Procedure. In-
troduce zero gas into the  continuous moni-
toring system sampling interface or as close
to the sampling interface as possible. When
the system output reading has stabilized,
switch quickly  to a known concentration of
pollutant gas. Record the time from concen-
tration  switching  to 95  percent  of final
stable response. For non-extractive moni-
tors, the  highest  available  calibration  gas
concentration shall be switched into and out
of the sample  path and response times re-
corded. Perform this test sequence three (3)
times. Record the results of each test on the
example sheet shown in Figure 2-6.
  7. Calculations. Data Analysis and Report-
ing.
  7.1 Procedure for determination of mean
values and confidence intervals.
  7.1J The mean value of a data set is calcu-
lated according to equation 2-1.
           i  n
        *-= 2*.
                    Equation 2-1
where:
  x,=absolute value of the measurements,
  2=sum of the individual values.
  x=mean value, and
  n=number of data points.

  7.1.2 The 95  percent  confidence interval
(two-sided) is calculated according to equa-
tion 2-2:
             —1
                          Equation 2-2
where:

  2x,=sum of all data points, t..,,=t,—a/2,
     and
  C.I...=95 percent confidence interval esti-
     mate of the average mean value.
                                       151

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Chapter I—Environmental Protection Agency
                                  App. B
             VALUES FOR '.975
                                   '1.975
2
3,, 	 , 	 	 . 	 	
4 	 „ 	
5,...., 	 	 	
6...,. 	 „ 	
7... . .
8,..., 	
9 	
10,....,, 	
11,,, 	
12,., 	 , 	
13..,..™ 	
14.. 	 , 	
15 ..
16., 	 „ 	

12.706
4.303
3 182
2776
2.571
2.447
2.365
2.306
2262
2.228
2.201
2 179
2.160
2.145
2.131

  The values in this table are already cor-
rected for n-1 degrees of freedom. Use  n
equal  to  the  number of samples  as  data
points.
  7.2 Data Analysis and Reporting.
  7.2.1 Accuracy (Relative). For each of the
nine  reference method test points, deter-
mine  the average pollutant concentration
reported  by  the  continuous  monitoring
system. These average concentrations shall
be determined from the  continuous moni—
toring system  data recorded under  7.2.2 by
integrating or averaging the pollutant con-
centrations over each of the time intervals
concurrent  with  each reference  method
testing period. Before proceeding to  the
next step, determine the basis  (wet or dry)
of the continuous monitoring  system  data
and reference  method test data concentra-
tions. If the bases are not consistent, apply
a moisture  correction to either reference
method concentrations or the continuous
monitoring system concentrations as appro-
priate. Determine the  correction factor by
moisture tests  concurrent with the refer-
ence  method  testing periods.  Report  the
moisture test  method and  the correction
procedure employed. For  each of the  nine
test runs determine the difference for each
test run by subtracting the respective refer-
ence method test concentrations (use aver-
age of each set of three measurements for
NO,)   from  the  continuous   monitoring
system integrated or  averaged concentra-
tions. Using these data, compute the mean
difference and the 95 percent confidence in-
terval of the differences (equations  2-1 and
2-2). Accuracy is reported as the sum of the
absolute value of the mean difference and
the 95 percent confidence interval of the
differences expressed as a percentage of the
mean  reference method value.  Use  the ex-
ample sheet shown in Figure 2-3.
  7.2.2 Calibration Error. Using the data
from paragraph 6.1, subtract the measured
pollutant  concentration determined under
paragraph 6.1.1 (Figure 2-1)  from the value
 shown by the continuous monitoring system
 for each of the five readings at each concen-
 tration measured under 6.1.2  (Figure 2-2).
 Calculate  the mean  of  these  difference
 values and the 95 percent confidence inter-
 vals according to  equations  2-1 and  2-2.
 Report the calibration error (the sum of the
 absolute value of the mean difference and
 the 95 percent confidence interval) as a per-
 centage of each  respective calibration gas
 concentration. Use example sheet shown in
 Figure 2-2.
  7.2.3 Zero  Drift (2-hour). Using the zero
 concentration values measured each 2-hours
 during  the field  test, calculate  the differ-
 ences between consecutive 2-hour readings
 expressed in ppm.  Calculate the mean dif-
 ference and  the  confidence  interval using
 equations 2-1 and 2-2. Report the zero drift
 as the sum of the absolute mean value and
 the confidence interval as a percentage of
 span. Use example sheet shown in Figure 2-
 4.
  7.2.4 Zero Drift (24-hour). Using the zero
 concentration values  measured every  24
 hours during the  field test, calculate the dif-
 ferences between the zero point after zero
 adjustment and  the zero value 24  hours
 later just prior to  zero adjustment. Calcu-
 late the mean value of these points and the
 confidence interval using equations 2-1 and
 2-2. Report the zero drift (the sum of the
 absolute mean and confidence interval) as a
 percentage  of span.  Use example  sheet
 shown in Figure 2-5.
  7.2.5 Calibration Drift (2-hour). Using the
 calibration values obtained at 2-hour inter-
 vals during the field test, calculate the dif-
 ferences between consecutive  2-hour read-
 ings expressed as ppm. These values should
 be corrected for the corresponding zero drift
 during  that  2-hour period.  Calculate  the
 mean and confidence interval of these cor-
 rected difference  values using equations 2-1
 and 2-2. Do not use the differences between
 non-consecutive readings. Report the cali-
 bration drift  as  the  sum  of  the absolute
 mean and confidence interval as  a percent-
 age of span.  Use  the example  sheet shown
 in Figure 2-4.
  7.2.6  Calibration Drift  (24-hour).  Using
 the calibration values measured every  24
 hours during the  field test, calculate the dif-
 ferences between  the calibration  concentra-
 tion reading  after zero and calibration ad-
justment, and the calibration concentration
reading 24 hours later after zero adjustment
but before calibration adjustment. Calculate
the mean value of these differences and the
confidence interval using equations 2-1 and
 2-2. Report the calibration drift (the sum of
the absolute  mean and confidence interval)
as a percentage  of span. Use the example
sheet shown in Figure 2-5.
  7.2.7  Response  Time.  Using the  charts
from paragraph  6.3, calculate  the time in-
                                       152

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App. B
   Title 40—Protection of Environment
terval  from concentration switching to 95
percent to  the final  stable value  for  all
upscale and downscale  tests.  Report  the
mean of the three upscale test  times  and
the mean of the three downscale  test times.
The two average times should not differ by
more than  15  percent of the slower time.
Report the slower time as the system  re-
sponse time. Use the example sheet shown
in Figure 2-6.
  7.2.8 Operational Test Period. During the
168-hour performance and operational  test
period,  the continuous monitoring  system
shall not  require  any corrective  mainte-
nance, repair,  replacement, or adjustment
other than that clearly specified as required
in the operation and maintenance manuals
as routine and expected during a  1-week
period. If the continuous monitoring system
operates within the specified performance
parameters and does not require  corrective
maintenance, repair, replacement or adjust-
ment other than as specified above during
the  168-hour  test period,  the operational.
period will be successfully concluded. Fail-
ure of the continuous monitoring system to
meet this requirement shall call for a repeti-
tion of the 168-hour test period. Portions of
the test which were satisfactorily  completed
need not be repeated.  Failure to  meet any
performance specifications shall  call for a
repetition of the  1-week performance test
period and that portion of the testing which
is  related  to  the  failed specification.  All
maintenance  and  adjustments   required
shall be recorded. Output readings shall be
recorded before and after all adjustments.
  8. References.
  8.1 "Monitoring Instrumentation for the
Measurement of Sulfur Dioxide in Station-
ary Source Emissions," Environmental Pro-
tection Agency,  Research  Triangle Park
N.C., February 1973.
  8.2 "Instrumentation for  the Determina-
tion of Nitrogen Oxides Content of Station-
ary Source Emissions," Environmental Pro-
tection Agency,  Research  Triangle Park.
N.C., Volume  1, APTD-0847, October 1971:
Volume 2, APTD-0942, January 1972.
  8.3 "Experimental Statistics," Department
of Commerce, Handbook 91, 1963, pp. 3-31.
paragraphs 3-3.1.4.
  8.4 "Performance Specifications for Sta-
tionary  Source  Monitoring  Systems  for
Gases  and Visible Emissions," Environmen-
tal Protection  Agency, Research Triangle
Park,  N.C.,   EFA-650/2-74-013,   January
1974.
        HlJ-Sange Calltratlcn <
        High-Range fsparl CaHbratiai ^js Mixture
                                                 Figure Z-l. Aiulysil of CallBratlon 041 nix
                                        153

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Chapter I—Environmental Protection Agency
                                                              App. B
              Calibration Gas  Mixture Data (From Figure 2-1)
              Hid (SOS)	ppm       High (90S)	ppm
  Run i
 Calibration Has
Concentration, ppnr
Measurement System
  Reading, ppm
Differences,   PPB


   4
  IS
  Kean difference
  Confidence interval
  Calibration error •
                   Mean Difference' + C.I.
                                                                 Wd    High
                      Average Calibration Gas Concentration
                                                 x 100
   Calibration gas concentration - measurement system reading
   Absolute value
                      Figure 2-2.  Calibration Error Determination
                                        154

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App. B
                                           Title 40—Protection of  Environment
rut
No.
1
2
Data
. and
Time


Reference Mstnod Samoles
SO,
Sampfs 1
( pp.ii }


3 1
4 i
S !
6 1
7
3
g
fean
:est
151 (
tecur
>Exf



reference rr
value (S02J
.onfidence i



ethod
ntervals *
Mean of
NO
Sampfe 1
(ppm)
NO
Sample 2
(ppm)
NO NO Sample
Sample 3 Average
(ppm) (ppm)
1




















j

|




Analyzer 1-Hour
Average (ppm)*
S02 NOX





i



Hean reference method
test, value (NO )
+ ppm
(SOJ • +
the differences > gjj confidence Interval .. ,„„ .
ac Mean reference method value " '" -
l»1n and report method used to determine Integrated averages












Difference
(ppm)
S02 NO,









Mean of
the differences
em
	 « Cso2
NOX)
.











' MX'
                              Figure 2-3. Accuracy Determination (SOj and NOX)
    Jata
    Set
    NO.
   Time
Begin   End
                              Date
 Zero
Reading
 Zero
 Drift
(aZero)
 Span
Reading
Span
Drift
(iSpan)
Calibration
   Drift
( Span- Zero)
    10
    14
    IS
       Zero Drift »  [Mean Zero Drift*
       Calibration Drift « [Mean Span Drift*
       •Absolute Value.
                                                       [Span] x 100
                                                         •t  [Span] x 1C
                            Figure 2*
                                        Zero and  Calibration Drift (2 Hour)
                                                  155

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Chapter I—Environmental Protection Agency
                                                                          App. B
Date                       Zero                Span
and           Zero        Drift              Reading
Time        Reading      (AZero)     {After zero adjustment)
                                                                        Calibration
                                                                           Drift
         Zero Drift  «  [Mean Zero Drift*	+ C.I. (Zero)

                          « [Instrument Span] x 100 « _____

         Calibration Drift « [Mean Span Drift* 	
                                                  + C.I. (Span)
                          4 [Instrument Span] x 100
           Absolute value
                         Figure 2-5.  Zero and Calibration Drift  (24-hour)
            Date of Test
            Span Gas Concentration

            Analyzer Span Setting _
                                 _ppm
                                 _ppm
            Upscale
                                 _seconds

                                 _seeonds

                                  seconds
                         Average upscale response .
                                                         seconds
            Dovmscale
                                 jseeonds

                                 _seconds

                                  seconds
                         Average downscale response

        System average response time  (slower tine) « _

        ^deviation from slower
        system average response
                                              _seconds

                                               seconds.
average upscale minus average downscale
              slower time
                                                              x 100X
                              Figure 2-6.  Response Time
                                            156

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   APPENDIX C



GLOSSARY OF TERMS
     157

-------
Abbreviations
                    Definitions
uBe
°C
cc
ft
ft2
ft3,
°F
Ibs
Mscfm
ppm
psig
psia
scfm

SCFH
sp.gr.
cf
Degree Baume
Temperature, degrees Centigrade
Cubic centimeter degree Fahrenheit
Feet
Square feet
Cubic feet
Temperature, degree Fahrenheit
Pounds
Thousands of standard dubic feet per minute
Parts per million by volume
Pounds per square inch gauge
Pounds per square inch absolute
Cubic feet per minute measured at standard
conditions (70°F) and 760 mm (29.22") Hg
Standard- cubic feet per hour
Specific gravity—compared to water at 60 F
CHEMICAL SYMBOLS

CH4

C02
H2°
HNO
N2°
NO
NOX
N0
                    Methane
                    Carbon dioxide
                    Water
                    Nitric acid
                    Ammonia
                    Nitrogen
                    Nitrous oxide (laughing gas)
                    Nitric oxide
                    Total nitrogen oxides in a mixture
                    Nitrogen dioxide
                    Nitrogen textroxide
                    Oxygen
                                      158

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 Words

 Absorber

 Baume (°Be)
 Definitions

 A stainless steel  tower with  bubble cap plates.

 Acid strength is determined by  use  of a floating
 instrument (hydrometer) calibrated  to read  °Be and
 by a conversion chart.  The Baume can also  be
 calculated if the  specific gravity  of the acid at
 60°F is known:
                                    °Be =  145 -    145
 Catalyst
 Catalytic
 reduction
 system
 Converter



 Effluent


 Emission

 Nitric acid  (weak)

Nitrogen oxides


Tail gas
                         sp.gr. '


 The platinum-rhodium woven wire gauze on which the
 ammonia is oxidized to nitric oxide and water.

 A device for reducing the emissions of nitrogen
 oxides  to the atmosphere by passing the gas over
 a catalyst in the presence of a reducing fuel such
 as  natural  gas,  hydrogen or ammonia.

 The  chamber in which the ammonia is converted to
 nitric  oxide and water by reacting it with air over
 a  platinum-rh~6dium catalyst.

 Waste gas  stream that enters  the atmosphere from
 the  process.

 Any  gas  stream emitted to  the atmosphere.

 Thirty  to  seventy  percent  nitric acid.

A general term pertaining .to  a  mixture  of  nitric
oxide (NO) and nitrogen  dioxide (NCL).

The gas leaving  the  nitric  acid absorber.
  *u.s. COVEHHMEHT PRINTING OFFICES 1985—537-002/21,507
                                     159

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.
  340/1-84-013
                                                             I. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
                                             5. REPORT DATE

                                                August 1984
  Nitric Acid Plant  Inspection Guide
                                                            6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
  G.  Saunders,
                                                            8. PERFORMING ORGANIZATION REPORT NO.
E. Wyatt
9. PERFORMING ORGANIZATION NAME AND ADDRESS
  PEI Associates,  Inc.
  11499 Chester Road
  Post Office Box  46100
  Cincinnati, Ohio  45246-0100   	
                                                             10. PROGRAM ELEMENT NO.
                                             11. CONTRACT/GRANT NO.

                                                 68-01-4147
                                                 Task No. 44
12. SPONSORING AGENCY NAME AND ADDRESS
  U.S.  Environmental  Protection Agency
  Stationary Source  Compliance Division
                                                             13. TYPE OF REPORT AND PERIOD COVERED
                                                 Task Final 8/84
                                             14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
  EPA Task Manager:   Kirk E. Foster,  Stationary Source  Compliance Division
16. ABSTRACT
  This inspection guide was written  and organized for  use by State and  local  enforce-
  ment field inspectors.  The purpose  of this guide  is to aid in the  development of
  uniform evaluation  procedures to determine compliance with NSPS requirements for
  nitric acid plants.   The manual describes the operating principles  for nitric acid
  plants and control  techniques that may be used to  determine compliance with
  regulatory requirements.
17.
                                 KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                               b.lDENTIFIERS/OPEN ENDED TERMS
                                                           c.  COSATI Field/Group
  Air Pollution
  Nitric Acid  Plants
  Emissions
  Air Pollution  Control Equipment
  Plant Inspection
  Continuous Monitoring
  NSPS
                                 Inspection  Procedures
                                 Maintenance and Record-
                                   keeping Requirements
18. DISTRIBUTION STATEMENT

      Unlimited
                                19. SECURITY CLASS (This Report)
                                   Unclassified
                                                                           21. NO. OF PAGES
158
                                               20. SECURITY CLASS (This page)
                                                   Unclassified
                                                                           22. PRICE
EPA Form 2220-1 (Rev. 4-77)   PREVIOUS EDITION is OBSOLETE

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