GUIDELINE SERIES
          OAQPS NO.  1.2-048
                    OOOR76010
        SIP PREPARATION MANUAL FOR NO.
  US. ENVIRONMENTAL PROTECTION AGENCY
    Office of Air Quality Planning and Standards





      Research Triangle Park, North Carolina

-------
SIP PREPARATION MANUAL FOR NOV
                             /\
 I
 I
 I
 I
 I
 •                                OAQPS NO. 1.2-048
 I
 I
 I
 I
                                     August 1976
 I
 I
 I                       U. S. Environmental Protection Agency
                       Office  of Air Quality Planning and Standards
                         •Control Programs Development Division
                              Research Triangle Park, N. C.
I
I
I

-------
  I
  I
INTRODUCTION
  |               The  Clean  Air  Act,  as amended  in 1970, provided that for each
  —          national  ambient  air quality  standard (NAAQS) promulgated by the
  •          Administrator,  a  State  Implementation Plan  (SIP) for each Air Quality
  •          Control Region  (AQCR) was to  be developed which was to contain emission
             control measures  that would provide for attainment and maintenance
  •          of  national  standards, generally within three years of the approval
             of  the SIP.   Experience  has shown that not all SIP's developed by the
  •          States in  early 1972 were adequate  to provide for attainment and main-
  •          tenance of the  nitrogen  dioxide (N02) standard by July, 1975.  Further,
             1t  is now  believed  that  continued growth of nitrogen oxide (NO ) emis-
                                                                          /\
 I          sions from mobile and stationary sources in a number of cases will make
             it  difficult  to maintain national standards in some areas where they
 •          are not presently being  exceeded.  Thus, additional NO  emission control
                                                                  A
 It          measures may  be necessary in  some areas to assure attainment and
             maintenance  of  national  standards.  This SIP Preparation Manual for
 •          NOX has been  prepared to provide guidance to EPA Regional Offices and
             State and  local control agencies on the development of an approvable
 I          control strategy for nitrogen oxides.

 I

 I

I

I

I

-------
  FORMAT
The SIP Preparation Manual for NO is separated into four
     I

     •

     •
     I
sections. Section I provides an overview of various factors that
must be considered in the development of an approvable control strategy I
for NO . Section II sets forth a fairly concise step-by-step procedure
|V

able control strategy. Section III provides, in question-and-answer —
format, additional information on recommended procedures outlined *
in Section II. Section IV provides a more thorough discussion of NO •
background information along with references to additional sources of
information.    |
This manual will be revised from time to time as new information
becomes available.
     I
     I
     I
     I
     I
     I
     i
     i
     i

-------
 I

 I

 I

 I

 I

 I

 I

 I

 I

 I

 I

 I

 I

I

 I

 I

I

I
                                                 TABLE OF CONTENTS
                                                                  Page
Section I:   Overview of NOX Control  Programs	   1

Section II:   Summary of Procedures Required for the Development
             of a State Implementation Plan Control Strategy for
             Nitrogen Oxides	   5

Section III:  Questions Frequently Asked Concerning NDx  	  17

     (A)  Control Strategy Development 	  17

          -  What is the NAAQS for N02?	  17

          -  Should a SIP control  strategy revision be delayed
            simply because no NO^ reference measurement technique
            has been promulgated at this time?	  17

          -  How large an ambient NOp data base is needed to
            develop a control strategy?	17

          -  Are available NO  emission factors satisfactory for
            control strategy development work? 	  18

          -  What automotive emissions factors should be used to
            estimate the anticipated impact of the FMVCP on auto-
            motive emissions of NO ?	  18

          -  Can NO  emission reductions be expected to result
            from Transportation Control Measures (TCM) implemented
            to reduce CO and/or Oj concentration?  	  18

          -  Should TCM's be adopted solely for NOX control?  ...  19

          -  Does the rolidack model  which is recommended for NO
            control strategy development work satisfactorily
            considering the different stack height of NO  sources
            in an urban area?	  19

          -  Should ambient NO  background concentrations be con-
            sidered in control strategy development work?  ....  20

     (B)  Ambient Air Quality Monitoring for N02	21

          -  What is the status of the development and promulgation
            of a new reference technique for NO,?	21

          -  What NO- ambient measurement techniques are satisfac-
            tory to provide ambient data to be used for SIP control
            strategy development work? 	  21

          -  Must a correction factor be applied to relate NO^
            data from one measurement technique to another?  ...  23

          -  How much ambient air quality data exists in EPA's
            SAROAD system? 	  23

          -  Historically, what type of ambient N02 air quality
            trends have been observed?	  25

     (C)  NOX Emission Data	  27

          -  What are tne major sources of NO  in the nation? ...  27

          -  What NO  emission data are needed to develop a control
            strategy?	29

          -  How is NO  produced during the fuel combustion process?  30

          -  Should the impact of stationary source fuel  switches
            required by the Energy Supply and Environmental  Coor-
            dination Act of 1974 (ESECA) be considered in the
            development of the NOX control  strategy? 	  31

          -  Historically, what type  of NO  emission trends have
            been observed?	33

-------
                                                               Pago

     (D)  NOX Control  Technology	   35

          - What Is considered to be reasonably available con-
            trol technology for stationary sources of NO ? .  .   35

          - Can significant NO  emission reductions be expected
            to result  from comoustion modifications to existing
            utility type boilers?	   35

          - What is considered to be achievable NO  control
            technology for stationary sources? 	   37

          - If achievable NO  emission limitations in conjunc-
            tion with  the FMVCP are not adequate to provide for
            attainment of the NAAQS for N0?, what type of addi-
            tional  control measures should be adopted? ....   38

          - Will the application of combustion modifications  to
            reduce  NO   emissions from utility type boilers
            effect  emissions of other criteria pollutants? .  .   39

     (E)  Miscellaneous  . . .-	   41

          - How is  NO  converted to N02 in the atmosphere?  .  .   41

          - Does HC control have any effect on ambient N02
           . concentrations?	 .  .   41

          - Are any existing stationary sources required to
            continuously monitor NO  emissions?  If so, which
            sources?	   41

          - Are new stationary sources of NO  required to
            monitor emissions?	   42

Section IV:  Support Information	

          History of NOX Control Under the Clean Air Act . .   .   Section A

          Current Status of Ambient fKL Measurement Methods -.   Section B

          NO- Formation Processes and Control Strategy
          Modeling  	   Section C

          Control of Oxide of Nitrogen for Stationary Sources    Section D

          Motor Vehicles	   Section E

          Transportation Control Plans 	   Section F

          Field Observations 	   Section G

-------
 I
 I
 I
 I
 1
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
I
I
              ABBREVIATIONS AND SYMBOLS
Act    -  the Clean Air Act as amended
AP-42  -  Compilation of Air Pollutant Emission Factors, EPA
APTIC  -  Air Pollution Technical  Information Center
AQCR   -  Air Quality Control  Region
CO     -  Carbon Monoxide
EGR    -  Exhaust Gas recirculation
EMSL   -  Environmental Monitoring and Support Laboratory, EPA
ESECA  -  Energy Supply and Environmental  Coordination Act
FGR    -  Flue Gas Recirculation
FGT    -  Flue Gas Treatment
FMVCP  -  Federal Motor Vehicle Control  Program
HDVD   -  Heavy Duty Vehicles-Diesel Powered
HDVG   -  Heady Duty Vehicles-Gasoline Powered
I/M    -  Inspection/Maintenance
LOT    -  Light Duty Trucks
LDV    -  Light Duty Vehicles
LEA    -  Low Excess Air
NAAQS  -  National Ambient Air Quality Standards
NMHC   -  Non-methane Hydrocarbons
NO     -  Nitric Oxide
N02    -  Nitrogen Dioxide
NOX    -  Nitrogen Oxides  (NO + N02)
NSPS   -  New Source Performance Standards
Ox     -  Oxidants
02     -  Oxygen
03     -  Ozone
OSC    -  Off-stoichometric Combustion
RACT   -  Reasonably Available Control Technology
SIP    -  State Implementation Plan
SAROAD -  Storage and Retrieval of Aerometric Data
TCM    -  Transportation Control Measure
TCP    -  Transportation Control Plan
TEA    -  Triethanolamine
TGS    -  Triethanolamine-guaiacol-sulfite
VMT    -  Vehicle Miles Traveled
VSAD   -  Vacuum Spark Advance Disconnect

-------
 I
                                    SECTION I
 I
                         OVERVIEW OF NO  CONTROL PROGRAMS
                                       X
I              The following statements  summarize the current knowledge  concerning
m         the nature and extent of the N02 problem and the  technical  information
•         available to assist in the development of approvable NOV  control
                                                                  X
I
           measures.
                1.   The primary and secondary National  Ambient Air Quality Standard
           for N0?  is 100 jjg/m  annual  arithmetic average.   The need for an addi-
 •
            tional  short-term  standard has been reviewed.  Based  on  available
 m          information,  it is thought unlikely that a short-term N02 standard
 •          will  be promulgated  in  the immediate future.  Therefore  SIP revisions
            for  NOo should address  the present annual standard and do not need to
 •          consider short-term  N02 concentrations.
                 2.   Although  limited, valid N02 data indicate that  only a few areas of
 I          the  country have ambient N02  concentrations in excess of the NAAQS for N02.
 K          On an overall national  basis, the N02 problem appears much less severe and
            pervasive than the total suspended particulate (TSP) or  oxidant (Ox) problem.
 fl|               3.   Difficulties with ambient N02 monitoring techniques have been
            principally resolved in the following manner:
 |                    (a)  The original Federal Reference Method for NO^j the
            Jacobs-Hochheiser  24-hr, bubbler technique, has  been  revoked and should
I
*          no longer be  used.
•                    (b)  The continuous chemi luminescence measurement principle
            and  associated calibration procedure was proposed in the Federal Register
|          on March  17, 1976, as the basis for the new Federal Reference Method
            for N02.
                      (c)  The (1) TGS (triethanolamine-guiacol-sulfite) and
•          (2) sodium arsenite  orifice 24-hr, bubbler methods are also

-------
                                                                            I
satisfactory for NC^ ambient monitoring and will  be tested for designation
as equivalent methods.                                                       J
           (d)   The  (1) continuous colorimetric (Saltzman) analyzer,
 (2)  TEA  (triethanolamine) and  (3) sodium arsenite  frit 24-hour bubbler     •
 methods  are  thought at this  time to be capable of  producing accurate        •
 air  quality  data and data collected by these methods can  be used for
 control  strategy development work.  However, the likelihood of any of       I
 these methods  producing valid  data over a year's time  is  not  as great
 as for the  previously mentioned methods.                                    9
           (e)   Data from the (1) Jacobs-Hochheiser or  (2) Saltzman          M
 24-hr, bubbler techniques should not be used.
      4.   With  a few exceptions, the typical annual N0?  problem, where       I
 it does  exist,  is  in an urban  area where observed  NO-  concentrations are
                                                    *                       •
 either slightly above or below the NAAQS.   Such  conditions generally        |
 represent a  potential problem  of maintenance of  the NAAQS rather than       «
 attainment of  such  standards.
      5.   Stationary source  control measures will become increasingly        V
 important as mobile source  controls become  more  fully  implemented.
 Studies  have been  conducted that predict future  violations of the  NC^       |
 standard will  occur  in some areas regardless of  automotive NO  emission     m
                                                                            I
 standards because of growth of stationary  source emissions.                 •
      6.   On a  national basis,  stationary sources and mobile sources         •
 contribute 60% and  40% of  the  NOV emissions, respectively.  In both
                                X                                           •
 emission categories, the vast  majority of  NO   emissions is produced         •
                                            X                               ^*
 by fuel  combustion  (fossil  fuel-fired  power plants, industrial  boilers,     _
 commercial/residential space heating units, gasoline-powered  automobiles,   •
 diesel-powered trucks, aircraft, etc.).                                     •
                                  2
                                                                            I

-------
  I
  •               7.   At this time the rollback model  (basic or modified)  is the
  ^          recommended source/receptor relationship for NOV control  strategy
  I
I
             review and/or development work.
 •               8.   Although the magnitude of the N02 problem and required
             reduction in NC)  emissions is not large, in general NOV control  tech-
                            X                                      A
 I          niques are limited (not reasonably available for all  source categories).

 I
      9.   The greatest activity in developing NOV control technology
                                                A
has been with utility type boilers and nitric acid plants.  NO  control
                                                              s\
techniques are more advanced for gas and/or oil-fired boilers than
             coal-fired boilers.  Reasonably available control measures for these
 •          source categories include:
                       (a)  For utility type boilers (greater than 250 x 106 BTU/hr
 •          heat input) - Combustion modifications
 tm                         (1)  Lower excess air
                            (2)  Staged combustion
 •                         (3)  Burner modification or replacement
                            (4)  Flue gas recirculation (for gas  or oil-fired boilers
with recirculation provisions)
          (b)  Nitric Acid Plants - Catalytic Decomposition
    10.  NOV control techniques which are not widely applied at the
           X
 •           present time or which are not presently available but which are expected
             to be available (i.e., achievable) in the next few years include the
 I           following:
—                     (a)  Utility type boilers (greater than 250 x 106 BTU/hr heat
 ™           input) - Combustion Modification
jl                          (1)   Water or steam injection (oil  or gas-fired)
                            (2)   Preheat reduction
I

-------
                                                                             I

               (3)   Derating can  be  considered  as  a  potential  NO              M
control  measure but it should be  reviewed on a  case-by-case basis             —
considering its effectiveness and feasibility.                                ™
               (4)   Firebox enlargement.                                      jtt
          (b)  Small and medium-size Commercial/Industrial  boilers
(less than 250 x 10  BTU/hr heat  input)  - Burner modification  or              I
replacement.
          (c)  Gas  turbines                                                  *
               (1)   Water and steam injection                                m
               (E)   New combustor designs
          (d)  Stationary internal combustion engines - exhaust gas          •
recirculation, turbo-charging with after cooling
          (e)  Chemical process (ammonium nitrate, fertilizer, explosive      •
production, etc.) - caustic scrubbing, NO  incineration in reducing           m
                                                                              I
atmosphere, etc.
          (f)  Industrial combustion processes (metallurgical, kilns,         •
glass production) - combustion modification
                                                                              I

                                                                              I

                                                                              I

                                                                              I

                                                                              I

                                                                              I

                                                                               I

-------
 I
 I
1
I
I
                                     SECTION II
                    SUMMARY OF PROCEDURES REQUIRED FOR THE DEVELOPMENT
I                   OF A STATE IMPLEMENTATION PLAN CONTROL STRATEGY  FOR
                                   NITROGEN OXIDES
 ft               The  following  section  discusses  the  nine  major steps  required
            in the development  of a SIP control  strategy  revision  for  N0?.   The
 ft          amount of work involved in  each  step  will  vary from area to  area
 _          depending on  available data, magnitude of N09  problem,  types  of NO
1                                                                            X
 9          sources,  etc.   The  nine steps can  be  summarized as  follows:
 •               STEP 1  - Determine if  available  N02  data  indicate  the NAAQS for
            N02 is being  exceeded or has the potential of being exceeded in the
 I          near future.
                 STEP 2  -  Determine if  the available  ambient  air quality  data  is valid,
 ft               STEP 3 - Determine the maximum representative  N02 concentration.

1
                 STEP 4 - Determine the area to be addressed by the NO  control
                                                                      A
            strategy.
                 STEP 5 - Determine the sources of NO .
                                                     /\
I
                 STEP 6 - Determine the growth potential for the study area.
                 STEP 7 - Using the proportional model, determine the NO  emission
                                                                        A
            reduction requirements.
                 STEP 8 - Determine NO  reduction expected to result from existing
                                      A
ft          NOX  regulation  (FMVCP, NSPS, etc.).
                 STEP 9 - Considering RACT and achievable control technology,
|          develop a control strategy to attain and maintain NAAQS for N02-  If
j|          needed, other control measures should also be incorporated into the
            NO   control strategy.
              X

-------
                                                                                       I
              Listed below and discussed in more detail  are  the  nine  principal          I
         steps for developing a State Implementation  plan  Control  Strategy
         for NO .                                                                       I
               X                                                                       JV
STEP 1:   Review available N02 air  quality  data  to  determine  if sufficient data          m
         are available to provide  evidence that the national standards are not
         being attained or will  not  be maintained.  Are  sufficient  data avail-          I
         able to calculate valid annual  average concentrations within the study
         area?  Valid data from at least one site  with one year  of  data should          J
         be available, however,  3  years or more of data are preferable.  Data          m
         should be available for areas of  expected maximum concentrations;
         however,  lack of such data  should not  preclude  the  development of a            I
         control strategy if available data indicate  valid violations of  national
         standards.  (Note:  Predictive models  do  not exist  to estimate ambient         |
         N02 air quality levels.)                                                       ^
STEP 2:   If data exist to indicate a potential  attainment or maintenance  problem,
         review the ambient air quality data to determine its validity and              B
         representati veness.
         (a)  Review the location  of the N02 monitors.   Are  they properly located       J[
         in accordance with siting criteria?* Are sites  biased  toward local  condi-     —
         tions such that they do not represent  areawide  problems?  (Note:   Local        ™
         problems should not be ignored, however, the objective  of  the  review is        •
         to determine the sources  and geographical area  to be considered  in  the
         control strategy analysis.)                                                   |
         *OAQPS presently plans to distribute a supplement to OAQPS Guideline          ••
          1.2-012 (Guidance for Air Quality Monitoring Network Design and Instru-      |
          ment Siting) by late 1976 which will  update existing N02 monitoring
          guidelines.                                                                  m
                                                                                       I

-------
 I
 I
 I
f
 1
I
I
I
 I
1
1
I
I
I
I
I
            (b)  Determine if a satisfactory measurement procedure was  used  to

            collect N02 data being analyzed.  The following measurement procedures

            are acceptable as indicated.  If data are collected by an  unacceptable

            measurement technique, data should not be used.
              Measurement  Method
                 (Method  Code)
               Instrumental

               (11)  Modified Saltzman
                    Colorimetric
               (12)  Saltzman Colorimetric

               (13)  Coulometric

               (14)  Chemiluminescence

               Bubblers -
         Comment
Data can be used with  caution *

Data can be used with  caution

Data can be used with  caution

Proposed Federal Reference  Method
Data can be used
               (71, 81, 91) Jacobs-Hochheiser - Data must not be  used

               (72, 82, 92) Saltzman Bubbler - Data must not be used
               (84) Sodium Arsenite Orifice

               (94) Sodim Arsenite - Frit

               (95) TEA

               (96) TGS
Candidate Federal Equivalent Method
  Data can be used
 Data can be used with caution

 Data can be used with caution

Candidate Federal Equivalent Method
 Data can be used
           *User should be aware of the  problems  associated with the method and be
            assured that proper procedures  were used  in  collecting  data.
            (c)  Analyze the available NCL air quality data to assure its validity

            and reliability.

-------
                                                                             I
     (1)  Determine if the data were collected by monitors  that are
properly operated, maintained and that adequate quality control proce-        £
dures were utilized to assure validity of data.                              _
     (2)  Review specific data for determination of abnormal  values.
Obtain frequency distributions of NOp data.   Air quality statistics          £
such as geometric mean, arithmetic meanfl standard deviation,  and fre-
quency percent!les may suggest abnormal  values.  For example:                g
     - Both the standard deviation and the magnitude of the difference        ^
between the geometric and the arithmetic mean are more sensitive to a        -•
few extremely high values than to many moderately high values.                •
     -  Inspection of the higher percentile values also will  identify
abnormal high values.                                                        •
     - Generally the standard deviation should not vary much  from year
to year.                                                                     •
     (3)  The collecting agency should attempt to validate  any  suspicious    »
data and to generally acknowledge that all the data have been reviewed
and are considered valid and useable for control strategy development        •
work.  Where necessary, this review should include:
          A.  Review of strip charts and laboratory reports,  and              V
field log books for notations concerning operations and maintenance           m
activities.
          B.  Review basic d-^ta to assure temporal balance  of air quality     •
data (e.g., a missing quarter of air quality data).
          C.  Have any changes been made in sampling methodology,             p
maintenance procedures, calibration procedures or quality control practices?  m.
     (4)  If abnormally high values have been measured and  are  considered
suspect, it may be useful to review operating parameters for other            •

                                                                              I

-------
  I
  I          instruments at the same monitoring site to determine whether electrical
             problems or heating/air conditioning problems may have caused abnormal
  m          values.
 f               (5)  Review data from nearby monitoring sites and compare the
             concentrations measured by the other instruments at those sites with
  m          the concentrations measured by sampling instruments at the site in question.
             (d)   To determine if N00 air quality concentrations are representative,
                                   I2
             review the N02 air quality trend at each site for the area being studied.
 _          To the degree possible, determine if unusual events may have caused
 '          high  NCL concentrations (e.g., industrial accident at nitric acid plant
 fl          or severe meteorological conditions that may cause unusually high N02
             concentrations.
 |               (1)  Review the NOo trend at each site to identify fluctuation in
I
1
1
I
            N02 levels.
                  (2)  Review parameters that would help explain trend.
                      - Review NOV emissions inventory, growth projections, construe-
                                 A
            tion permits, and compliance information to determine if any significant
            changes  (increases or decreases) in regional NOX emissions have taken
            place.  NOTE:  The purpose of Step 2 is to insure that the data which
•          will  be used as the basis of a control  strategy are  valid,  or can  reason-
A          ably  be assumed to be valid.   If it is  believed that the  data are  question-
            able  and factors exist that could reasonably challenge the  data  validity,
•          then  such data should not be used as the  basis  of  a  control  strategy.
            If on the other hand, all  reasonable measures have been followed in  the
•          collection of the data,  and unless the  validation  efforts prove  the  data
            to be invalid, then such data should be assumed valid and usable.

-------
                                                                                        I
STEP 3:   Determine the maximum measured  ambient level  that  best  represents
         ambient air quality levels  in the  area.   Determine if such  air quality          •
         data are of sufficient magnitude that a  further  analysis  of existing            B
                                                                                        I
         and anticipated emissions data  should be conducted to determine  if
         national standards will  be  attained   and maintained.  This  analysis             •
         should be conducted if ambient  air quality levels  are equal to or
         exceed national standards.   Also,  in  those areas where  growth of new            B
         emission sources is expected, the  analysis should  be conducted even  if          ^
         national standards are being attained on a marginal basis.                      "
STEP 4:   Determine the geographic area to be considered in  the analysis.  From          W
         available data, determine the geographic area where national standards
         are violated or are anticipated to be violated due to growth of  emission        •
         sources.  It is not necessary to use  an entire AQCR or  county.   The             fc
         area does not have to be a  political  entity.   Some consideration should        "
         be given to political boundaries,  however, since the regulations which          •
         implement the control strategy  will ultimately be  enforced  by  local
         governments.  Although some advantages accrue to the use  of a  commonly          •
         identified geographical  area, as long as the  area  is clearly defined,
         it is appropriate for development of  a control strategy.  The  area of          •
         concern should be "future-oriented,"  in that  strong consideration  should        ••
         be given to growth of emission  sources.
              More specifically, data indicate that areas slightly downwind from        V
         the major urban center but   within the urban  area  are  the .expected
         areas of maximum annual  NOo levels.   Ambient  NCL levels 20  miles or  more        m
         distant from the urban fringe are affected to a very minor  degree  by           f
         urban NOX emissions.  Similarly, sources generally located  more  than
         20 miles from the urban areas will minimally impact air  quality within thp    •
                                      10                                               •

-------
 i
 I
 I
•
I
 I
 •          urban area.  It is recommended therefore that the geographic area to
             be considered for NO  control strategy for attainment purposes include
                                 |X
             the urban area and the adjacent counties.  Of course from a maintenance
             point of view, growth of sources throughout some area larger than the
             current urbanized area may need to be considered.  In such cases, areas
 •           of expected growth should be considered in'defining the geographical
             area to be addressed by the NO  control  strategy.
                                           X
    STEP 5:  Determine the sources of NO  emissions in the area and calculate the
                                        A
             emissions from each source.  Data are needed for two purposes:
             (a)  To assess where the ambient N02 problem originates.
             (b)  To determine the emissions reduction impact of various possible
             control regulations on source emissions.
 •           Most emission inventories are adequate to provide for the assessment of
             the sources of NOV emissions in the area, however, for certain emission
                              IX
             categories such as fuel combustion sources, available data may not be
 m           adequate for possible control strategy development.  Specifically,
             detailed information on fossil fuel-fired steam generators (e.g., excess
 •           air usage, boiler configuration, number of burners, fuel specifications,
             etc.)  is needed to determine a boiler's emission reduction potential.
 I                Similarly, detailed information for mobile sources such as vehicle
 m           mix ratio (LDV, LDT, HDVG & LDVD)  and age distribution for the area under
             study may be necessary to determine the impact of the FMVCP and/or
             various transportation control measures.  Since this type of information
             is not commonly associated with existing emission inventories, it may
P           be necessary to collect some additional data.
_                More specific procedures for compiling an emission inventory are
—           contained within Guide for Compi 1 i ng a_ Comprehensive Emission Inventory
                                           11

-------
                                             I
     (EPA/APTD 1135, March 1973). Further, specific information, as well      •
     as emission factors that can be used to calculate NOV emissions from
                               A
     various mobile and stationary sources, are contained in Compilation of    I
     Air Pollutant Emission Factors (AP-42).
STEP 6:  Determine the expected increase of NO emissions due to growth (generally   •
                        A
     over the next 20 year period). Growth is an inherent part of air       •
     pollution control; and consideration of growth is thus paramount
     in the development of a control strategy.  The adjustment of the emissions  V
     inventory to account for growth is essentially a projection of the levels
     of economic and demographic activity and its impact on air quality in     9
     the area of concern.                              •
          The information needed to develop growth factors originates
     from Federal agencies, from State and local governments, and from private   •
     business interests. Fairly specific information should be obtained from
     State and local planning agencies if possible. If unavailable, the      •
     growth projections of the Office of Business Economics (QBE), presently    m
     the Bureau of Economic Analysis of the U. S. Department of Agriculture
     can be used. These projections, called "OBERS projections" are avail-    •
     able at the EPA Regional Offices. Since most NO is produced from
                             §V
     on these source categories (power plants, industrial boilers, commercial/   »
     residential space heating, mobile sources, etc.).
       Numerous guidelines have been prepared by EPA with regard to       V
     projecting growth in emissions and allocating such growth. These
                     12
                                            I
                                            I

-------
 I

 •          techniques are too detailed to summarize here.  The reader is referred
 M          to the following documents for additional information:
                  Air Quality Maintenance Guidelines:
 ti                    Vol. 3, Plan Preparation (EPA-450/4-74-003)
                       Vol. 7, Projecting County Emissions (EPA-450/4-70-008)
 Q                    Vol. 13, Allocating Projected Emisssions to Sub-County AQMA
                                (EPA-450/4-74-004)
 ™ STEP 7:  Using the proportional model, determine the degree of control needed
 •          to attain and maintain the NAAQS.  The modified rollback is also recom-
             mended for NO  control strategy development work.
                          A
                  The Modified Rollback can be expressed as:

                                                  . = l  QiV future
             where X, = SIP design value (representative maximum annual average
                        N02 concentration in base year)
                   X2 = NAAQS for N02 (100 yg/m3)
                  B = annual N02 background concentration (8 yg/m3)
9                Q.  = annual NO  emission rate per source category
                   1             A
m                G.J  = a growth factor, e.g., the ratio of N02 emissions at attainment
                       data or during maintenance period to N02 emissions in the base
ff                     year per source category
                  N = the number of source categories
I                i = a particular source category,  e.g., light-duty vehicles,
                      stationary sources, etc.
1
I
I
X2
- B
X — R
N
2 (
i = 1
N
n' base year
i
                                               13

-------
In cases where the area-wide NO  emissions  result from a variety of
                               /\
(a)  Consider the impact of the FMVCP on NOV emissions.   Figure II-l
                                           X
                                                                                       I

          source types with differing  emissions  and  growth  rates  and where              »
          various control  strategies are  to  be  investigated,  the  modified roll-         •
          back model  will  allow  the situation to be  studied in  more detail  than
          the rollback procedure.                                                       •
               To apply this technique,  the  left side of the  equation  is evaluated
          with available data to determine an allowable  NO   emission rate.   The         •
                                                         X
          right side  of the equation is  then evaluated for  various control  strate-       m
          gies until  a strategy  which  demonstrates attainment and assures mainte-
          nance is developed.                                                           •
STEP 8:   Determine how large an NOV emission reduction  can be  achieved  by  full
                                                                                        I
          implementation of existing adopted control  regulations.                       •

          presents a  plot of projected national  NOV  emissions from motor vehicles.
                                                 X
          Additionally, AP-42 can be used to develop city specific curves  if            •
          needed.
          (b)  Consider the impact on  NOV emissions  (both increases and  decreases)       |
                                        X
          that may result from (1) compliance with existing control regulations,        »
          (2) ESECA or other fuel switches,  (3)  TCM  or I/M  program for CO  or Ox.
STEP 9:   If additional controls are needed, consider the application  of (a) reason-    V
          ably available control technology  and if needed (b) achievable control
          measures (technology forcing).   The  term  "achievable" is  intended to          J
          require reasonably "technology forcing" control measures if  necessary,        «
          rather than simply "off-the-shelf  technology." SIP revisions  submitted       *
          by July 1977 shall require  all  achievable  control technology for stationary   M
          sources (as needed) to provide for attainment  of  the  national  standard.

                                         14
                                                                                        I

-------
I
I
I
      1.4
      1.2
   c    *
   o
   in
   to
I
•-
I
I
I
I
      1.0
   (b
   CJ
   -C
   O)
   s_
   o
   -a
   0)
   N
      0.8
      0.6
       0.4
 I
 1
 I
 I
 I
 I
 I
       0.
       o.o1—
        1970
                               FIGURE II-l
               NORMALIZED  MOTOR VEHICLE EMISSIONS
                                       I
                                    I
     1975
Assumptions:
1980           1985
  CALENDAR YEAR
1990
1995
                   1.   National  average automobile and truck age distribution
                   2.   Low altitude,  standard conditions
                   3.   3% Compounded  (annual) growth rate
                   4.   National  average vehicle mix  (LDV 80.4%; LOT 11.8%; HDG 4.6%; HDD 3.2%)
                   5.   1970 composite emission  factor  4.6  g/mi
                                                  15

-------
                                                                          I
     Additionally,  if  needed,  "other" control measures, including
land use and transportation  control measures, should be adopted and        ™
submitted by July 1978.                                                    •
                                                                          I
                                                                          I
                                                                          I
                                                                          I
                                                                          I
                                                                           I
                                                                           I
                                                                           I
                                                                           I
                                                                           I
                                                                           I
                                                                           I
                                                                           I
                                                                           I
                                                                           I

-------
 I
I
I
                  SECTION III - QUESTIONS FREQUENTLY  ASKED  CONCERNING  NOX
                              - Control  Strategy  Development -
             QUESTION - What is  the NAAQS for N02?
 •          ANSWER - The primary and secondary NAAQS for  N02  is  100 jjg/m   annual
 fl          arithmetic mean measured as  N02-  Recently a  review  was performed  to
 *          determine the need  for an additional short-term NO-  NAAQS.  Based  on
 fl          available information, it is thought unlikely that a new  short-term
             standard will be developed in the immediate future.   SIP  revisions
 •          should only address the present annual  NAAQS  for  N02.
             QUESTION - Should a SIP control  strategy revision be delayed  simply
because no NOo reference measurement technique  has been promulgated
at this time?
ANSWER - No.  Detailed studies of ambient N02 measurement techniques
 •           have been completed which assess each measurement technique.   The
             results of these studies  indicate that valid data can  be  obtained  using
 •           various methods.  Control strategy development work  should  be  initi-
 •           ated using representative N02  air quality data.
             QUESTION - How large an ambient N02 data base is  needed to  develop a
 •           control strategy?
             ANSWER - As a minimum,  valid annual  air quality data from at  least one
 m           site is required.  Although the seasonal variability of N02 is minor  in
 M           most areas,  N02 air quality data should be  available  for all  four quar-
             ters of the year of interest to accurately determine the  annual  arithme-
 •           tic mean.   Additionally,  2 or  3 years of valid data  from  a  monitoring
             site are preferred to a single year's data.   Further,  data  from more
|           than one site is preferable, including a site at  the area of probable
maximum concentration.
                                 17

-------
ADDITIONAL INFORMATION - See Section G - Field Observations
QUESTION - Are available NO  emission factors satisfactory for control           I
                           x                                                    VI
strategy review or development work?
ments be used for NO  control strategy development work.
                    /\
                                                                                I
ANSWER - Generally, yes.   NO  emission factors are satisfactory for a
                            s\
regional assessment of total NOV emissions but may be less accurate for
                               /\
estimating some individual  source emissions.   For example, NO  emission
                                                             X
factors for coal combustion (and fuel  oil  in  some cases) represent              •
average emissions for typical  conditions and  at this time do not directly
allow for consideration of the variable nitrogen content of coal.  In           |
many cases 50% but in extreme cases up to 80% of the NO  emitted from           H
                                                                                I
coal combustion is associated with the nitrogen in the fuel.  The nitrogen
content of U. S. coals can vary  from 1.0% to 2.0%.  It is recommended          I
that emission factors contained in AP-42 and  its associated update supple-
                                                                                I
QUESTION - What automotive emission factors should be used to estimate          _
the anticipated impact of the FMVCP on automotive emissions of NO ?             *
                                                                 X
ANSWER - The automotive emissions regulations (FMVCP) associated with           V
ESECA are in effect.  Congress is currently considering Act amendments
and may revise them.  Until the amendments are completed, the current           £
exhaust emission limitation associated with the FMVCP should be used            _
for SIP control strategy work.  Additionally, procedures and data               ™
described in AP-42 can be used to develop city specific automotive emis-        •
sion factors.
QUESTION - Can NOX emission reductions be expected to result from               •
Transportation Control Measures (TCM) implemented to reduce CO and/or
03 concentration?                                                               •

                                                                                I

                                                                                I

-------
 I
 I
 I
           ANSWER - Some NO  emission reductions can be realized from some of
            •               X
I           the CO-0  TCM's but the measures used in the CO-0V TCM's must be
                   X                                        X

           carefully analyzed to assess the amount of NO  control achieved.  For


 I
           example,  reductions  in vehicle miles  travelled  (VMT),  retrofit of



           exhaust gas recirculation (EGR) or vacuum spark advance  disconnect (VSAD)



           can directly reduce  NOV emissions.  However,  inspection/maintenance
                                 X


I           programs  (I/M)  for CO-0  TCM's may have  little  effect  on NOV  emissions.
                                  X                                   X


           ADDITIONAL INFORMATION - See Section  F  - Transportation  Control  Measures.



I         QUESTION  - Should TCM's be adopted solely for NO  control?
           T  ...	                                        X


           ANSWER -  Reductions  in NOV  emission from CO and/or  Ov  TCM's should be
           	                      X                           X


           determined and  incorporated into the  NO   control  strategy as  applicable.
                                                 /\


•         At this time it is thought  unlikely that NO   reduction would  become a



           key determinant of TCM policy, however  in certain areas, such measures



m         in conjunction  with  stationary source control may be required to provide



           for attainment  of N00 standards.
I


•         strategy development work satisfactorily consider the different stack



I


I
           QUESTION - Does  the rollback  model  which  is  recommended  for  NO   control
            "~~JT ~ '  "                                                     X
           height of NOV  sources  in  an  urban  area?
                       /\
          ANSWER  - Yes,  generally 1 to 3 hours is required for NO to N02 conver-



          sion, thus NO  emitted from low and high level sources in the problem


          area is constantly diffusing and mixing while N02  is forming and  results
fl         in NO  source contributions being nominally related to stack height.


           Therefore in most cases the proportional model will satisfactorily


|         describe the urban NOX emission - N02 air quality relationship on an


m         annual basis and is the best readily available model for NO  control


I                                                                     '
w         strategy development work at this time.
•         ADDITIONAL INFORMATION - 1.  See Section C - NOX Formation Processes


           and Control Strategy Modeling.


I

                                           19

-------
                                                                                I
QUESTION - Should ambient NOp background concentrations be considered
in control strategy development work?                                           I
                                                                       3
ANSWER - Yes.  An annual  average N02 background concentration of 8 ug/m
should be assumed for control strategy development if other background          "
concentration data are not available.  Natural  background concentrations        •
are a result of natural bacterial  and plant actions.
                                                                                I
                                                                                I
                                                                                I
                                                                                I
                                                                                I
                                                                                I
                                                                                I
                                                                                I
                                                                                I
                                                                                I
                                                                                I
                                                                                I
                               20                                               I
                                                                                I

-------
 I
 •                    - Ambient Air Quality Monitoring for NCL -
 mj        QUESTION - What is the status of the development and promulgation  of
          a new reference technique for ML?
 fl        ANSWER - The Environmental  Monitoring and Support Laboratory,  EMSL,  has
          completed its study of ambient NOV measurement methods.   The chemilumin-
                                           |X
          escence measurement principal and associated calibration procedure was
 —        proposed to the public in the Federal Register on March  17, 1976,  as the
 *        basis for the new NO^ reference method.   The schedule for other actions
 •        is listed below:
          Date                 Action
 •        3/76  Propose continuous chemiluminescence measurement principle and
                calibration procedure  (40 CFR Part 50).
 I        3/76  Propose reference and equivalency requirements (40 CFR Part 53).
 •        10/76  Promulgate measurement principle and calibration procedure:
                promulgate reference and equivalency requirements.
 •        2/77  Designate reference methods  (40 CFR Part 53) and identification
                of acceptable commercial instruments.
 I        3/77  Designate equivalent methods  (40 CFR Part 53).  (Arsenite and TGS
j|              are expected to be designated as equivalent methods.
          ADDITIONAL  INFORMATION - Current Status of Ambient N02 Measurement Methods
|        QUESTION -  What NO^ ambient measurement techniques are satisfactory to
          provide ambient data to be used for SIP control strategy development
|        work?
-        ANSWER - Three ambient N02 monitoring methods are reliable and capable
          of producing valid N02 air quality data on an annual basis for control
P        strategy development work.   The methods are (1) the continuous chemilumin-
          escence measurement principle and associated calibration procedure,
                                             21

-------
                                                                                I
(2) TGS (triethanolamine-guiacol-sulfite)  and  (3)  sodium  arsenite orifice         _
24-hr, bubbler methods.   The continuous  chemiluminescence measurement            ™
principal  and associated calibration  procedure has been proposed in  the           •
Federal Register on March 17, 1976, as the basis  for the  Federal Reference
Method for N02>  The TGS and sodium arsenite orifice 24-hr,  bubbler  methods       I
will be tested for designation as  equivalent methods.                             B
     At this time it is also thought that three other methods when               m
properly used  can also produce valid air quality data for control                 m
strategy development work.  However, the likelihood of any of these
methods producing valid data for an annual average is not as great as            •
for the previously mentioned methods.  These less reliable methods are
the (1) continuous colorimetric (Saltzman) analyzer, (2)  TEA (triethanola-       |
mine)  and  (3)  sodium arsenite frit 24-hr, bubbler methods.
                                                                                 I
ADDITIONAL INFORMATION -  See Section A - History of NO  Control Under the
   """  ~      ™                                           X
Clean Air Act.  Section B - Current Status of Ambient N02 Monitoring             l[
Methods.  The following reports from EPA's Environmental Monitoring
Series are also available from the Air Pollution Technical Information           |
Center (APTIC):                                                                  _
     1.  EPA-650/4-74-019-a:  Collaborative Testing of Methods for               ™
Measurement of  N0~ in Ambient Air, Volume 1 - Report of Testing.                 ff
     2.  EPA-650/4-74-031:  Evaluation of Triethanolamine Procedure
 for  Determination  of Nitrogen Dioxide in Ambient Air.                            •
     3.  EPA,-650/4-74-046:  Collaborative Test  of  the TGS-ANSA  Method           g
 for  Measurement of Nitrogen Dioxide  in Ambient  Air.
     4.  EPA-650/A-75-011:  Collaborative Test  of  the Continuous  Color-           •
 metric Method for  Measurement of  Nitrogen  Dioxide  in Ambient  Air.
                                                                                  I
                                22
                                                                                  I

-------
 I
 I
                5.  EPA-650/4-74-047:   An Evaluation of TGS-ANSA Procedure for
           Determination of Nitrogen Dioxide in Ambient Air.
                6.  EPA-650/4-74-048:   An Evaluation of Arsenite Procedure for
 -
 *        Determination of Nitroqen Dioxide in Ambient Air.
 •             7.  EPA-650/4-75-019:   Evaluation of Effects  of NO,  C02,  and
           Sampling Flow Rate on Arsenite Procedure for Measurement  of N02  in
 |        Ambient Air.
 _             8.  EPA-650/4-75-021:   Evaluation of Gas Phase Titration  Technique
 *        as Used for Calibration of Nitrogen Dioxide.
 •             9.  EPA-650/4-75-022:   Evaluation of Continuous Colormetric Method
           for Measurement of Nitrogen Dioxide in Ambient Air.
 I             10.   EPA-650/4-75-023:   Comparison  of Methods  for Determination
 •        of Nitrogen  Dioxide  in  Ambient Air.


       '    QUESTION  - Must a correction  factor be applied to  relate  N02 data from
 •        one measurement technique to  another?
           ANSWER -  No correction  factor is  required to relate N0? data from
 |          different measurement  techniques assuming they  have been operated
 _          properly.  Each acceptable monitoring technique provides reliable
 ™          information with respect to  ambient N02 levels.
 B          QUESTION - How much ambient  air  quality data exist  in EPA's SAROAD system?
            ANSWER - Listed in  Table III-l are summary  statistics of the  1974 N02
 |          data contained in SAROAD as  reported  in the 1974 Monitoring and  Air
            Quality  Trends Report.   More current  data are generally available from
I
•                                          23

-------
                        TABLE  III-l


NO  AMBIENT AIR QUALITY MONITORS IN USE-NATIONAL TOTAL
  £t
•-\
Measurement Method
(Method Code)
instrumental
11) Modified Saltzman Colorimetric
[12) Saltzman Colorimetric
[13) Coulometric
14) Chemiluminescence
TOTAL
iubblers
(84& Sodium Arsenite
94) (Orifice & Frit)
(95) TEA
(96) TGS
TOTAL
GRAND TOTAL

„ u f (1)
Number of
Monitors Reporting
131
10
8
72
221
1196
0
5
1201
1422(2)

AQCR's Reporting
39
5
8
35
87
158
0
1
159
168
Total No. of
AQCR's Reporting
Based on 1974 Trends Report (updated) and does not include Jacobs-Hocheiser
or Saltzman Bubbler data.
Note that only 610 sites (106 AQCR's) of the 1422 sites (168 AQCR's
reporting) have reported enough ambient NO? air quality data to calculate
an annual mean.
I
I
I
I
I
 I
 I
 I
 I
 I
 I
 I
  I
  I
  I
  I
  I
  I
                              24

-------
 I
 I        SAROAD and State agencies.  The Regional  Offices, State and local
           air pollution control agencies are encouraged to submit any additional
 |        N02 air quality data obtained to SAROAD so that it can be stored for
 .        future reference.
 ™        QUESTION - Historically, what type of NO,, air quality trends have been
 fl        observed?
           ANSWER - Trends in ambient N02 concentrations at CAMP sites have been
 |        analyzed for Chicago, Cincinnati, and Philadelphia.   The N02 graphs
           and regression lines (See Figure III-l)  indicate, for the most part,
 9        an increase in annual average concentration with time.
I                Further, it is now believed that continued growth of NO  emissions
                                                                       X
           from stationary sources in a number of cases will make it difficult
 •        to maintain the NAAQS for NO^ in some areas where they are not presently
           being exceeded.   Thus,  additional control  of NO  emissions may be
                                                          |X
           necessary in some areas to restrict the  upward trend of NO  emissions
           to assure the attainment and maintenance  of the NAAQS for NOp.


 I

 I

 I

 I

 I

I

I

-------
                             FIGURE III-1

               N02  Air Quality Trends  at CAMP Sites*
a
u
   200



   100


    0
   100


   50
 0
100
 50



 0
100


 50
    0
   100
   50
                                                       CHICAGO •
                                                        CAMP
                                                         CINCINNATI
                                                           CAMP
                                                           DENVER"
                                                            CAMP
                                                       PHILADELPHIA'
                                                          CAMP
                                                          ST. LOUIS"
                                                           CAMP
         1962   1963   1964   1965   1966   1967   1968   1969   1970   1971

                                   YEAR
Station
Chicago
Cincinnati
Denver
Philadelphia
St. Louis
CAMP average
Annual Average N02
Concentration (/jg/m3)
1962-66
86.1
62.0
66.0
67.7
58.5
68.1
'1967-71
101.2
60.1
67.9
77.6
54.2
72.2
Percent
Change
+18
- 3
+ 3
+15
v- 7
+ 6
   D  Valid annual  average

   o  Indicates  average based  on incomplete data

   *Measurements  made with  Modified  Saltzman  (colormetric) Method,  the
    National Air  Monitoring Program:  Air Quality and  Emission Trends:
    Annual  Report: Volume  I: EPA-450/1-73-001-a.
                                       26
I
I
I
I
I
I
I
I
I
I
 I
 I
 I
 I
 I
 I
 I
 I

-------
 I


                             I- NO  EMISSION DATA -

                                 X


 _         QUESTION - What are the major sources of NO  in the nation?

 I
 "         ANSWER - Nitrogen oxides (NO ) are formed by nature and as a result of
           1 ' "                          A
I
I



I



I
           urban areas.  Natural emissions of NO  are considerable when the entire
                                                A
I           man's activities.  Both sources principally emit NO  in the form of

                                                              x

           nitric oxide (NO).  Although the natural  emissions which occur as a



Jj         result of bacterial and plant actions exceed man-made emissions by a



           factor of 10 on a worldwide basis, man-made emissions predominate in








•         geographical land area of the nation is.considered, but because of their



           low emission density (tons N0x/square mile), they only result in a N0?



•         background concentration in the order of 8 ug/m .   Man-made NOX emissions



           in 1972 amounted to 24 million tons within the United States.



•              On a national basis, 60% of the man-made NOV  is generated by station-
                                                           A


•         ary sources and the remaining 40% by mobile sources (see Figure III-2),



           but the distribution can vary for specific AQCR's.   For example, based



•         upon emission data in NEDS the stationary/mobile source ratio  is 76% - 24%



           for the St. Louis AQCR and only 43% - 57% for the  Denver AQCR.



•              Most NO  stationary source emissions are generated by the combustion
                       A


           of fuel.  On a national basis, utility and industrial boilers  emit 67%



           (49% utility and 18% industrial) of the stationary source NO  emissions.
                                                                       A


•         Other sources of NO  include stationary internal combustion engines (prin-



           cipally used for natural gas transmission pipeline pumping stations



|         located in nonurban areas, 19%) and commercial/residential space heating



           (7%).  Non-combustion NOX sources which include nitric acid production,
           TNT production, etc., contribute only 7% of the national  NO  emissions.
                                                                      A
                                            27

-------
STATIONARY - '10'iILE  SOURCES
                                                                                     lndintrl.1 Prx>c«» licit (31)

                                                                                     C«s Tu.blnt (?t)

                                                                                     Non-combuitlon (1JJ

                                                                                     InelncriUon (< Tt)
                                                                        STMIOMARY SOURCES
                                     Figure  III-  2
      MOBILE SOURCES
              NATIONAL DISTRIBUTION  01  NO  EMISSION SOURCES (197?)

                                         28
      i
      I
      i

      i
      I
      j
      i






















































p.

i-1
t  <
«  ;

-------
•

•

I
  I
I                  On a national basis, 76% of the mobile source NO  emissions are
                                                                  X
             generated by gasoline-powered motor vehicles (light duty - 59%, heavy
  •          duty - 13%, and off-road 4%).  Additionally, diesel-powered motor vehicles
             contribute another 20% (heavy duty - 14% and off-road - 6%) of the
  •          nation's NO  emissions.  The remaining 4% of the national emissions are
                        A
             contributed by railroad, aircraft, vessels, etc.  Because diesel-powered
             trucks are not commonly used in urban areas, gasoline-powered motor
             vehicles are the major urban mobile source of NOV emissions.
                                                             A
             QUESTION - What NO  emission data are needed to develop a control
                               A
             strategy?
             ANSWER - On a national basis, stationary sources contribute approximately
             60% and mobile sources contribute about 40% of the total NOV emissions
                                                                        X
 •          (principally as NO).  Thus an emission inventory for the problem area
             should include both categories of sources.  In order to access the mobile
 |          source  emission  rates,  data  should be  obtained on  mobile source population
 g          by category, expected growth rates, age distribution, information on
 *          vehicle miles traveled (VMT) and fuel consumption information.  Additional
 I          information may be required if mobile source controls (i.e., TCM* for
             carbon monoxide (CO) or oxidants Ov)) in addition to the Federal Motor
                                               |X
             Vehicle Control Program (FMVCP) are being evaluated.
 —                For stationary sources,  information on the location of large point
 *           sources and emission density of area sources is required to determine
 •           their impact on ambient N02 concentration.  Although some processes
             such as nitric acid production emit enough N02 at one plant to be a point
I             source, most NO  point sources will probably be large industrial boilers
                            A
m           or power plants.   Specified data on each large industrial or utility
•
            *TCM - Transportation Control  Measures
                                            29

-------
     Both the NO  emission inventory and ambient N00 data base used for
                A                                  c
                                                                                 I
boiler will be required if the control strategy is to address these              •
sources.  Specific data should include information on the type of fuel
(specifications), firing configuration, excess air controls, number              I
of burners, burner arrangement, availability of new low NO  producing
                                                                                 I
replacement burners, secondary air ports, etc.  In some cases, such as           •
coal-fired boilers, individual sources may have to be studied to deter-          •
mine NOX control potential.  The emission inventory should accurately
describe NOX emissions for the year of record and identify any scheduled         I
increases or decreases in emissions.
                                                                                 I
control strategy development work should be for the same year of record.         m
If the current NO  emission inventory is deficient and an update is
                 A
required, it may be possible to efficiently and accurately develop the           I
inventory by principally addressing the major emission sources in the
study area.                                                                       g
ADDITIONAL INFORMATION - See Section D - Control  of NO  for Stationary
Sources.
—
I
9
M
I
QUESTION - How is NOV produced during the fuel  combustion process?
ANSWER - As previously indicated, the principal  stationary and mobile
sources of NOX emissions are fuel combustion processes (utility boilers,         V
industrial boilers, motor vehicles, etc.).  These processes generate NO
by two formation mechanisms.  The principal formation method is the high         |
temperature oxidation of the nitrogen in the combustion air supply to            _
produce NO.  Thermal NO is formed in all combustion processes, but predomin-     •
ates for cleaner fuels  (low nitrogen content fuels) such as gasoline             •
(mobile sources) and natural gas and light oil  (stationary sources).  For
other fuels with greater nitrogen content  (lie., heavy oil and coal used         J
                                  30
I

-------
 I
 I          by larger boilers), NO  is also formed by the oxidation of the nitrogen
             in the fuel.  For coal, approximately 50% of the NOV emissions are
                                                                |X
             formed in this way and in extreme cases up to 80% of the NO in the
 g          exhaust gas is associated with the fuel nitrogen.
                 Because of different specific heats, nitrogen content, excess air
 •          requirement, etc., of different fuels, each fuel has a different NO
             formation potential per BTU.  As shown in Table 111-2, the combustion
I             of coal (high nitrogen and excess air requirement) produced more  NO   per
                                                                                 J\
             BTU than a clean gaseous fuel such as natural  gas.  Thus for the same
 •          heat input rate (10  BTU/hr) a coal-fired combustion unit would typically
             •produce greater NOV emissions than a natural  gas or oil-fired unit.
                               X
             QUESTION - Should the impact of stationary source fuel switches required
 I          by the Energy Supply and Environmental Coordination Act of 1974 (ESECA)
             be considered in the development of the NO  control strategy?
 I
 •          ANSWER - Since the N02 problem is typically an urban problem and most
 •          ESECA fuel switches will  be required for utility boilers, the location
             of power plants in the study area should be reviewed to determine if
 •          they will impact the urban area.  Power plants 20 miles or more from
             an urban problem area generally will have minor impact on the  urban
 •           problem area on an annual basis.  If the source is expected to impact
I             upon the problem area, the increase in NO  emissions  resulting from
                                                      X
             oil or gas-to-coal fuel switches should be considered as an emission
 •           increase that must be offset by other NO  emission reductions.  One
             factor to consider is that boilers which are  combusting  oil or gas  but
I
I
were originally designed for coal-firing emit substantially less NO  than
                                                                   /\
a furnace designed for oil or gas-firing.  This is because the combustion
                                31

-------
             TABLE  III-*
NO  EMISSIONS PER BTU OF HEAT  PRODUCED
  A
Fuel
(Nitrogen
Content)
Coal
(1-22N)



on


(0.1-
0.5%N)


Gas

(Negligi-
ble %N)
Type of Unit
Utility/Large Industrial
Cyclone (Pulverized)
Wet Bottom (Pulverized)
General (Pulverized)
Indus trial /Commercial
Domestic
Utility
General
Tangential
Indus tri al /Commerci al
Horizontal
Tangential
Domestic
Utility
Industrial
Commercial
Domestic
Emissions-Potential
(#NO Y/10b BTU)
/\

2.08
1.25
0.75
0.63
0.25

0.75
0.36
0.57
0.28
0.09
0.57
0.11 - 0.22
0.11
0.08
                    32
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

-------
  I
  I
  I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
I
I
chamber designed for coal firing would be much larger than needed for


oil or gas combustion and this large size tends to reduce NO  emissions
                                                            A

because of the reduced flame temperature.  The important point is that


if these low  NO  producing boilers switch to coal, this will result in a
               A

greater increase in NO  emission rate than expected based on established
                      A

emission factors.  This is because the baseline NO  emissions for the
                                                  A

gas or oil-fired boiler (designed for coal) is substantially less than


indicated by  emission factors for gas or oil-firing of boilers designed


for these fuels  (See Table III-3).
TABLE III-ijJ
UTILITY BOILERS* - FUEL SWITCHING
(NOV Emissions Ibs NO/106 BTU)
A A
Fuel

Coal
Oil
Apparent Emission
Increase from
Fuel Switch
Actual
Percent Increase
Boiler Designed for
Referenced Fuel

0.9
0.7
0.2
28.5%
Boiler Designed
For Coal Firing

0.9
0.3
0.6
200%
*Front Wall Fired

QUESTION - Historically, what type of NO  emission trends have been
                                        A

observed?


ANSWER - NOX emission rates have generally increased since 1940 princi


pally because of the increase in number of motor vehicles and fossil

fuel-fired stationary sources in use (see Figure III-3).
                           33

-------
     For the overall period 1940 to 1970, the average growth rate of NOY
                                                                       /\

emissions from motor vehicles and stationary fuel combustion sources

were very similar, being 4.8 percent per year, respectively.  Over the

period 1940 - 1960, however, the average road vehicle emission growth

rate was 4.9 percent and the stationary fuel combustion source growth

rate was only 2.0 percent.  During the period 1950 to 1970, these trends

were reversed, and the road vehicle emission growth rate decreased

to 4.6 percent while the rate for stationary fuel combustion sources

increased to 7.3 percent.  Over the last 10 years through 1970, NO
                                                                  A

emissions from steam-electric power plants increased at a rate of

7.4 percent per year.
                          1950      I960
                             YEAR
1970
              Figure III- 3- Nationwide emissions

                for N0₯  (1940 - 1970). *
                      /\
*A much more detailed discussion, including tables and methodology,
 is presented in Nationwide Air Pollutant Emission  Trends, 1940  - 1970,
 Ap_115                                             	
                                34
I
I
I
I
I
I
 I
 I
 I
 I
 I
 I
  I
  I
  I
  I
  I
  I

-------
I
•                             - N0x Control Technology  -
I
             coal-fired  boilers.   Listed below are reasonably available  NO  control
                                                                         X
            QUESTION  - What is considered to be reasonably available control tech-
            nology for stationary sources of NO ?
                                               X
•          ANSWER -  The greatest activity in developing NO  control technology has
            been with utility type boilers and nitric acid plants.  Reasonably
•          available control technology exists for both of these source categories.
•          Utility type boilers are  typically the largest NO  stationary source
            emission  category and in  those areas where additional control is needed,
            •these sources should be analyzed for NOV control potential.  NO  control
                                                   X                       X
            techniques are more advanced for gas and/or oil-fired boilers than
I
•          techniques:
*          (a)  Utility type boilers  (greater than 250 x 106 BTU/hr heat input)  -
•               Combustion modifications
                 1.   Lower excess air
Jj               2.   Staged combustion
—               3.   Burner modification or replacement
*               4.   Flue gas recirculation (for gas or oil-fired boilers with
•                    recirculation provisions)
            (b)  Nitric Acid Plants - Catalytic Decomposition
|          QUESTION  - Can significant NOX emission reduction be expected to result
            from combustion modifications to existing utility type boilers?
•          ANSWER -  Generally, yes.  Table III-| lists typical NOX emission reduc-
            reduction in NOV emissions).
                           A
•           tion factors that can be expected to be achieved  (up to 50% or greater
I
I

-------










































«*•

1— 1
1— 1
I—I

O)
f—
jn
ro
I—






































1


oo
25
t

cr>
CQ

1 1 1
Q.

i—

>;
i — i
_i
i — i
L_
i
~D
O
1—

o
»_-<

CJ
h— 1
Lu
i — i
O
o


3.
o
1-^
1—

ID
co
3£
V.O
O
^TT
o
Q;
• i

eg
j i
I —
	 i

oo
LU
C£
oo
r3"
o
t — 1
1—

^z>
d;
UJ
ct:
X
o
•rfST

~— J
( 	 )
i — i
O-
1>-
J- —

0
23
•a:

00
_J
LU
^»
LU
_J

X
0
*£


•^
CD
i — <
[ — •
ex
^ 	 )
t — i
Lu
i — i
Q
O
5Z

O
i — t
1—
Co
ID
03
2:
o
O
re
| 't
^

2:
o

t—
o
^~->
o
LU
rv

X
O


^£



c
o
£
o
rs
-^i
C1J
C£

•^J
t)
O
	 1

S-?
CM



a:
CD
LU




*
-$c
+ 01
c
e^ *r—
LU cn
_J ro
40
oo





X
o
*-—
~o
QJ
f—
i —
O
$_
4-J
C
~r°

c
rr>




f —
01
ZJ
Lu





OJ
CX
>^
) — .

i-
QJ
t — .
• i —
O
CQ
I CO
O o-i i.
"O o -o
ai r— ra
V- -^ 0
O r—
X JD
O 5-5
2: s_ in
O cxi
i — *+-
rO T3
U 00
• I — C^ C^
CX 0 4->
I— -M 5



r~-~ O
ID M-
1 1
o





CM in en
r\ in in
i i i
*s?" G} '-J'
CM CM CM






r--- co en
ro CM «^f-
1
f — .
CM






, — .
o
o
•S.

O O 0
in in o
ro ro 10
i i i
000
o o o
i — i — . ro







,_ 	
00 i — rO
n) -i— O
CD O O






i — i — i —
rcJ rO T3
•r- *r— -r-
-M 4-> 4-J
c c: c
a; oj QJ
Di CD CD
c c c
T3 *^ rO
i— i— i—






• •
a>
t_
ro

C
O
• 1 —
4->
O
-o



UD
«^j-
1 1
ro





cxi in
r^~ *x!"
i i
ro >J3
CXI CM






ro in
CM ro
i i
in o-i
r— i —





	 *
0
0 0
in in
•d- -S

0 0
O in
r^-. in
i i
0 O
ro in
i — CM








00 I 	
rO 't*~
O O






1 — 1 —
r — • r—
rO ro
~^ I3C

4~J 4-^
d C
O O
i_ s_
Lu Lu





fe-'1 ?3 ;,s
o o ex)
ro r— r—


• . < • . •
to i — i —
ro 'i — rO
 en in
i i i
in o o
CM O O
 CO O




>•> >i
r— r—

r fr^ r-j
rO 4-J "a 4-> ~O
is ecu ecu
O oo O oo
4-> MO tsl O
c -r- rx -r- ex
o s- ex t_ rx
i- 00 0 O
LU re ^:






















i i i






co
«^j-
i i t

ro






CO IO
CM r—
i i i
•— o
CXI ,—










o
0 O O
O O CXI
en in i —
i i i
O O O
0 O 0
«=}- ro in







r— ,
ro i — rfl
O -f- O
0 O 0




>^
, 	
, —
ro
4-J -a
ecu a; a>
O 00 C C
MO O O
•r- Q. r— I—
s- ex u o
0 O >, >,
re c_> cj
CD
C

,^
C *4-
o
•r- -O
4-> QJ
rO oo
1 — rO
^5 *r—
O jQ
*~
•i — ^
^rl o

QJ
E
O
•r—
.C
CJ
•i —
O
4J
00
1
O|—
tj
o
£^
t , r.
re QJ
01
to ro
oo •*-*
QJ JO
0 1
X 0
QJ ^
4—*
s_
OJ oo
S O
° X3
— 1 ^
1 Tl
C"
^^ *— )
L i 1
. — 1
•
C
o
4 —
4-J
00
_§
EH
O
oo O
oo "O
ro ttj
-Q CD
rO
>>•*->
S- 00
•o

•> o
CM
O i/>
c
55 O
ro ••—
4_J
C2J ra
•r-
E s-
CX ro
CX ^*
* -X
36
I
I
I
 I
 I
 I
 I
  I
  I
  I
  I
   I
   I
   I
   I
   I
    I
    I

-------
 I

 ™         QUESTION - What is considered to be achievable NO  control  technology
 •         for stationary sources?
            ANSWER - NO  control  techniques which are not widely applied at the
             *~~         X
 •         present time or which are not presently available but which are
            expected to be available (i.e., achievable)  in the next few years
 •         include the following:
 •              (a)  Utility type boilers (greater than 250 x 10  BTU/hr heat
            input) - Combustion Modification
 •                   (1)  Water or steam injection (oil or gas-fired)
                      (2)  Preheat reduction
 •                   (3)  Derating can be considered as a potential  NO  control
                                                                       X
 •         measure but it should be reviewed on a case-by-base basis considering
            its effectiveness and feasibility.
 •                   (4)  Firebox enlargement
                 (b)  Small and medium-size Commercial/Industrial boilers (less
 |         than 250 x 10  BTU/hr heat input) - Burner modification or  replacement
                 (c)  Gas turbines
                      (1)   Water and  steam injection
I                    (2)   New combustor designs
                 (d)   Stationary internal  combustion  engines  - exhaust  gas  recircu-
|          lation,  turbo-charging with  after  cooling
                 (e)   Chemical  process  (ammonium  nitrate,  fertilizer, explosive
.
*
I
            production, etc.)  - caustic scrubbing,  NO  incineration  in  reducing
                                                     X
I          atmosphere, etc.
                 (f)   Industrial  combustion  processes  (metallurgical,  kilns,  glass
            production) - combustion modification
                                           37

-------
QUESTION - If achievable NO  emission limitations for stationary sources          •
                           A


in conjunction with the FMVCP are not adequate to provide for attainment          •




of the NAAQS for N(L, what type of additional  control measures should




be adopted?                                                                      •
ANSWER - All achievable NO  control  technology for existing NO  sources

                          A                                   A
must be carefully analyzed to assess the amount of NOV control  achieved.
                                                     X
 NO   emissions.
  X
                                  38
                                                                                 I



                                                                                 I
must be required if necessary and be submitted by July 1, 1977.



     All other measures needed to attain and maintain must be submitted



no later than July 1, 1978.  These "other measures" should be comprehen-



sive and innovative where needed, and should include items such  as land          I



use measures, transportation controls, transit improvements,  zoning



ordinances, building codes, inspection/maintenance programs for  station-.         g



ary and mobile sources.                                                          _



Transportation Control Measures (TCM's)                                          ™



     Although it is thought unlikely that NOV control will be a  key              •

                                            X                                    •

determinant in the foreseeable future, NOV emission reductions can be
                                         X
obtained from some of the TCM's for CO and/or Ox but the measures used           |



                                                                      1.
For example, retrofit of exhaust gas recirculation (EGR), vaccum spark




advance disconnect (VSAD), or gaseous fuel conversion can directly               •




reduce NOV emissions.  However, inspection/maintenance programs (I/M),
         A
if not specifically designed for NO , may have little or no effect on            I
                                   A                                             ••








      NOX  emission  reductions can also be obtained from reductions in



vehicle miles  traveled  (VMT).  Methods to reduce VMT include traffic             I



restrictions,  limited access zones, traffic-free zones, street closing
                                                                                 I

                                                                                 I

-------
I

I
           and other similar measures.  VMT can also be reduced through mass
•         transit improvements such as express bus-carpool lanes, improved bus
•         service, and rapid rail service.  See Section F - Transportation Control
           Plans for more detailed information on this subject.
•         Stationary Source Control Measures
                NO  reductions from stationary combustion sources must be required
           as necessary.  Such measures may include innovative energy conservation
m,         measures such as requiring (1) increased thermal insulation and storm
™         windows and doors, (2) the use of power plant reject heat, (3) the use
•         of central heating units for residential and commercial space heating
           and other energy saving measures.  Additionally, a fuel tax on the
|         nitrogen or BTU content of fuel  may be useful  to encourage conservation
_         measures.
            ADDITIONAL  INFORMATION - See  Air Quality Maintenance  Planning and Analysis,
•          Volume 4:   Land Use  and Transportation  Considerations (EPA-450/4-74-004).
I
I
QUESTION - Will the application of combustion modifications to reduce

NO  emissions from utility type boilers effect emissions of other criteria
  X
pollutants?

ANSWER - The application of reasonably available NOV control techniques
°°~~~ * " *                                             /\
I         (combustion modifications) to fossil fuel-fired steam generators are
           usually related to changes in the design of the boiler and/or burner
|         configuration.  Any of the combustion modifications presented in this
I           document can usually be used to reduce NOV emissions to meet most NO
                                                    X                          X
           emission limitations.  The flue gases leaving the boiler (firebox) area
•         can be treated for other pollutants as required.  One of the techniques

                                           39
I

-------
                                                                               I
for NO  control, reduction of excess  air,  may increase  smoke but the
amount does not become significant unless  very low excess  air rates are        I
used.   This is balanced by the fact that as these pollutants increase,
boiler efficiency is reduced, which is a waste of BTU's and the danger         ^
of explosion increases.  This situation is usually watched closely             •
and not tolerated by boiler operators, especially today.  Utility boilers
are less affected than industrial  or  smaller boilers because they nor-         I
mally have higher heat release rates.  The use of reasonable and achievable
combustion techniques for NO  control should not affect the operation or       •
                            A
efficiency of a control device used to control other pollutants.               •

                                                                               I

                                                                               I

                                                                               I

                                                                               I

                                                                               I

                                                                               I

                                                                               I

                                                                               I

                                                                               I
                               40                                              •

                                                                               I

-------
I

                                   - Miscellaneous -
            QUESTION - How is NO converted to NQ2 in the atmosphere?
•          ANSWER - Although there are many atmospheric reactions involving
            NO - N02 transformation, only a few of the mechanisms are predominate
I          in the basic conversion processes.  The NO emitted into the atmosphere
            by sources combines with oxygen (0~), ozone (Oo) or some type of organic
I
•          compound to form N02.  The NOo in the atmosphere can be photodisassociated
•          by sunlight to form NO.  While these NO - N02 reactions are in process,
            both NO and N0? may also be removed from the reactive mechanisms by
I          combining with organic and/or inorganic radicals to form nitrates
            (such as PAN) which are photochemically unreactive.
I          QUESTION - Does HC control have any effect on ambient N02 concentrations?
•          ANSWER - Available laboratory studies have indicated that changes in the
            non-methane hydrocarbon/nitrogen oxides (NMHC/NO ) ratio for an area may
                                                            X
I          influence N02 concentrations.  The studies indicated that if HC reduc-
I

_
™
            tions exceed NOV reductions, thus reducing the NMHC/NOV ratio, peak NO
                           X                                      X
            concentrations may be reduced but the annual average NOo concentration
            may increase.  However, the NMHC/NOX relationship is preliminary, hence it
            is not recommended that HC emissions be considered in an NOX control strategy
•          at this time.
            QUESTION - Are any existing stationary sources required to continuously
|          monitor NO  emissions?  If so,  which sources?
                      X
•j          ANSWER - Yes.  On October 6, 1975,  the Agency promulgated regulations
            (40 FR^ 46240) requiring the revision of SIP's to include requirements for
I          the continuous monitoring of emissions from certain  categories of

I

-------
                                                                               I
stationary sources.  Included in these regulations  was the requirement
for the monitoring of NO  emissions from fossil  fuel-fired steam gener-        •
                        f\                                                      ^^^
ators and from nitric acid plants in AQCR's where the Administrator has        _
specifically determined that a_ control strategy for NOo is_ necessary.           ™
                            6
A minimum size of 1,000 x 10  BTU/hour heat input for boilers and 300           •
tons/day (100% acid) production capacity for nitric acid plants was also
established for these monitoring requirements.  The regulations are            •
complex and the reader is referred to applicable Federal Register for
specific details.  Any NOY SIP revisions that have been determined to          •
                         /\
be needed shall include emission monitoring requirements for regulated
sources.
     Revisions to SIP's to require continuous emission monitoring must         •
be submitted by the States to Regional Offices by October 6, 1976.  The
State regulations may allow an additional 18 months after EPA approval         •
of the SIP revisions for sources to procure, install, and begin operating      •
the monitoring instruments.  Quarterly reports of (1) emissions in excess
of SIP emissions limitation, and (2) the monitoring system downtime must       •
be submitted by the sources to the States.
                                                                               I
ANSWER - Yes.  The October 6, 1975, Federal Register  (40 FR_ 46250)             -
contains regulations under 40 CFR, Part 60, New Source  Performance Stan-       ™
QUESTION - Are new stationary sources of NOV required to monitor emissions?
                1                           X
dards, requiring all new fossil fuel-fired steam generators greater
than 250 x 10  BTU/hour heat input and new nitric acid plants to continu-
ously monitor their emissions of NO .   Certain boilers, those capable
                                   X
                                                                               I
                                                                                I
                                                                                I
of demonstrating operation during performance tests at below 70% of the         _
emission standard» are exempted from the NO  monitoring requirement.            •
                                           /\
Sources must submit quarterly reports of excess emissions and monitoring        •
system downtime to EPA Regional Offices.
                                                                                I

-------
  I                                  SECTION A
  _                HISTORY OF  NO   CONTROL UNDER THE CLEAN AIR ACT
  I
  I               Under the mandate of  Section 109 of  the Clean Air Act as amended
             (1970),  the Administrator,  on  April  30, 1971, promulgated in the
  |          Federal  Register  (36  FR_ 8186)  as Part 410 of 42 CFR, national ambient
  £          air quality standards (NAAQS)  for particulate matter, sulfur oxides,
  ~          carbon monoxide,  photochemical oxidants,  hydrocarbons (oxidant  guide),
 •          and nitrogen dioxide. These air quality  standards were  to be attained
             and maintained in all AQCR's through the  implementation  of various
 I          emission limitations  as  specified by each State in their State  Implemen-
             tation Plan (SIP) for each Air Quality Control Region (AQCR) within a
 •          State.  The NAAQS set for  nitrogen dioxide were 100 jjg/m (0.05 ppm),
I             annual average,  for both the primary and  secondary standard conditions.
                                                          3
             A 24-hour average standard for N0? of 250 jjg/m  (0.13 ppm) was  proposed
 •          but not  promulgated because "No adverse effects on public health  or
             welfare  have been associated with short-term exposure to nitrogen dioxide
 I          at levels which  have  been  observed to occur in the ambient air",  at
 •          that time.  A subsequent recodifi cation on November 25,  1971, resulted
             in the NAAQS being contained in 40 CFR  50.11.
 •                                       SIP's
 •                SIP requirements were published on August 14, 1971, as 42  CFR,
             Part 420 and were recodified as Part 51 of 40 CFR on November 25, 1971.
|           These requirements included, in Section 51.14, the requirement  that all
             AQCR's where measured annual arithemetic  average ambient N0? concentrations
•
             were greater than 110 AJa/m, be designated Priority I.   It was assumed that
I
I

-------
                                                                                I
 emission reductions resulting from the Federal  Motor Vehicle Control            «
 Program (FMVCP) would reduce ambient levels to the standard (100 juc
 by 1975, thereby not requiring control  strategies to be developed for          •
 those AQCR's only slightly in excess of the NftAQS for N02 (110 wg/m3 vs.
 100 ,ug/m ).   Ambient air quality data used in  determining the priority         |
 classification of the AQCR's in relation to N02 were generally based           ^
 on the Jacobs-Hochheiser measurement technique.  In the absence of             ™
 measured air quality data, priority classifications were to be determined      •
 by population, i.e., AQCR's with an "urban place" population (1970)  of
 greater than 200,000 would be classified Priority I for N02-  A total           I
 of 47 AQCR's (19%) of the 247 AQCR's were classified Priority I, 25  (53%)
 of those AQCR's being interstate AQCR's.  All  other AQCR's were classi-        I
 fied Priority III.                                                             •

            CONTROL STRATEGY REQUIREMENTS FOR NITROGEN DIOXIDE
     Each Priority I AQCR was required to submit a plan which set forth         I
a control strategy that provided the degree of emission reduction               •
necessary for attainment and maintenance of NAAQS.
     The emission reductions necessary to attain NAAQS for N02 standards        •
were to be calculated with the use of the proportional model.  Control
strategy requirements for  N02 were based upon the following measures  (as        |
needed):                                                                        «
     (a)  the utilization of the FMVCP for NO:
                                             /\
     (b)  consideration of any additional reduction in NO  that would be        •
an indirect result of a transportation control  plan designed either for
the control of  carbon monoxide or photochemical oxidants; and                    |
                                A-2
I
I

-------
  I
  •               (c)  the application of reasonably available control  technology
              (RACT) on stationary sources of NO  (e.g., power plants and nitric
  •          acid plants).
                   Should the combination of measures (a) (b)  and (c) not demonstrate
  •           attainment and maintenance of the N0£ standard,  the original SIP control
  •           strategy was to also include the use of RACT for the control of stationary
              sources of hydrocarbons.   If these measures were adopted,  it was expected
 I
 I
I
I
               that  the  NCL standard would be attained.

                    It should  also  be noted that no TCP's*were required solely for

               the control of  NOV.   It was believed that automotive emissions of  NO
                               X                                                  A
               did not contribute a large enough portion of the total  NO  emissions
                                                                       X
              in an area such that a TCP designed specifically for Ntk would be an
 I
               efficient method  to  address  NOV control.
                                            j\
                   The NO   control  strategy requirements  were  amended late  in  1971
                        X
 I           (36 FR_ 25233, December 30, 1971) to delete the requirement for RACT for
 M           control of hydrocarbons from stationary sources.  This change was based
             upon a reappraisal of information on the role of hydrocarbons in the
 I           atmospheric conversion of NO to NO^ resulting in the conclusion that
             the reduction of hydrocarbons from stationary sources did not play a
 |           significant role in the reduction of long-term (annual) ambient N02 con-
«           centrations.  With the deletion of this requirement, it was assumed
*           that the NO^ standard would be achieved if control measures (a) (b) and
             (c), identified above, were implemented.
             *TCP  = Transportation  Control Measures
I
                                                A-3
I

-------
                                                                               I

                                                                               I
               APPROVAL/DISAPPROVAL OF SIP's                                    _
     On May 31, 1972, EPA published in the FIR (37 F£ 105,  at 10842)             •
notifications of approval and disapproval  of  State Implementation  Plans         •
submitted by States earlier in the year.   Included in the  Federal
Register were notices of disapproval for the  NO   control strategies             I
                                              /\                               ^^"
for the 21 AQCR's listed in Table A-l.  The predominate reason for these
disapproval actions was that the SIP did not  require the application            V
of RACT for stationary sources of N0x within  AQCR's with N02 problems.           •
     To correct the inadequacy of these SIP's, EPA proposed regulations
on June 14, 1972 (FJ^ 11826), to require the use  of RACT in AQCR's                I
requiring N0v control strategy.  The AQCR's in Table A-l would be made
                                                                                I
subject to EPA promulgated regulations if the State did not adopt  approv-       jj
able regulations before EPA promulgation.   In this same FR_notice, EPA           M
acknowledged that there was some difficulty with the routine field
use of the Jacobs-Hochheiser ambient monitoring  technique  and, because           I
of that fact, the proposed regulations would  not go into effect until
July 1, 1973.  Similarly, States that had adopted NO  regulations  would          J|
not be expected to require compliance before  any EPA promulgated regula-        _
tions.  In the interim, further ambient measurements would be made to           ™
affirm the validity of the Jacobs-Hochheiser method.
                         MEASUREMENT CONTROVERSY
I
     In the FR^ of June 14, 1972, at 11826, the Administrator took note
of the fact that there were  problems associated with the routine field          •
use of the Jacobs-Hochheiser method, the method designated as the federal
reference method for NO  (see Appendix F, 40 CFR, Part 50).  The problem         |
                       /\
with the reference method was caused by two factors that had become
                               A-4
 I

-------
  I
  I
  I
  I
  I
  I
  I
 I
 I
 I
 I
 I
 I
 I
 I
 I
I
I
                        TABLE  A-l
21 AQCR'S WITH DISAPPROVED N0v CONTROL STRATEGIES AS OF MAY 31, 1972*
                             /\
AQCR             AQCR NAME
 NO.

015  Phoenix-Tucson
024  Los Angeles
042  Hartford-New Haven-Springfield
0.43  New York-New Jersey-Connecticut
045  Philadelphia
070  St. Louis
085  Omaha-Council Bluffs
115  Baltimore
123  Detroit-Port Huron
151  Scranton
160  Rochester
162  Buffalo
195  Altoona
196  Harrisburg, PA
197  Pittsburgh
214  Corpus Christi-Victoria
215  Dallas-Fort Worth
216  Houston-Galveston
220  Salt Lake City
223  Norfolk
225  Richmond
     AFFECTED STATES
Arizona
California
Massachusetts
New York, New
Pennsylvania,
Missouri
Nebraska
Maryland
Michigan
Pennsylvania,
New York
New York
Pennsylvania
Pennsylvania
Pennsylvania
Texas
Texas
Texas
Utah
Virginia
Virginia
Jersey
New Jersey
New Jersey
*The control strategies for Atlanta (GA), Washington, D.C. (MD),
Flint (MI), Toledo (NI), Memphis (TN), and Seattle (WA)  AQCR's
were also disapproved but were later approved (Sept.  22, 1972 and
Oct. 28, 1972) after the respective states submitted additional
information.
                               A-5

-------
                              A-6
                                                                                  I
                                                                                  I
apparent during a revaluation of the method.   First,  the  method was
found to have a variable collection  efficiency—the  range  was  from                  •
about 50% to 70% at low levels of N02 to  about 15% at  high levels of
N0?.  The second problem was  a nositive interference from  NO that could             •
cause NOp readings to be more than 100% greater than the actual value.              •
     After an intensive laboratory and field investigation of  the Jacobs-
Hochheiser method (and other methods believed to be  more accurate), it              •
was concluded that the Jacobs-Hochheiser  method was  unreliable and should
no longer be the reference method.  Hence,  in the FR_ on June 9, 1973,               m
at 15174, EPA proposed to delete the Jacobs-Hochheiser method  as the                •
reference method.  Three other reference  methods, or "tentative candidate
methods" were proposed.  These included the arsenite bubbler  (orifice),             •
continuous chemiluminescence, and continuous Saltzman.  Of these, the
method with the greatest potential accuracy was  considered to be the               |
chemiluminescence technique.                                                        _
     Comments were solicited from the public and scientific community               *
on the proposed new methodologies while lab and field  investigations                 I
continued to determine the accuracy of the  three candidate methods  and
other methodologies .                                                                J

              IMPACT OF MEASUREMENT CONTROVERSY ON SIP's                             •
     In addition to deleting the Jacobs-Hochheiser method  as  the federal
reference method, the Agency took three other significant  SIP  related                |
actions in the Federal Register in June,  1973, necessitated by the                   «
faulty Jacobs-Hochheiser data base upon which SIP's  were based.
I
I

-------
I
I
                 First, EPA prooosed, on June 8, 1973 (38 FFM518Q)  to reclassify
 _          43 of the 47 Priority I AQCR's for N02 from Priority I  to Priority III.
 ™          This was necessitated because current and valid N02 data was  collected
 •          which indicated that no N02 problem existed in the 43 AQCR's.   The
            remaining Priority I AQCR's were Los Angeles, Chicago,  New York-New
 I          Jersey-Connecticut, and Wasatch Front (Salt Lake City).   Because ambient
            N0? levels were significantly above the NCL standard in  Los Angeles
 •          and Chicago, these AQCR's remained as Priority I AQCR's.  Since the two
 •          remaining Priority I AQCR's (i.e., New YorkrNew Jersey-Connecticut
            and Salt Lake City) had ambient levels only slightly above the national
 •          standards, it was proposed that additional  information  be collected in
            these AQCR's before any action was taken to either reclassify them to
 •          Priority III or to request a revised control strategy.    Additionally,
                                             3
 •          valid ambient data above 110 ug/m  had become available  for Denver,
            which had originally been classified Priority III.  Since the data were
 •          inconclusive, no action was taken at that time to reclassify  Denver.
            However, it was proposed that additional data be collected in Denver.
 •               Secondly, in the same FR_ action, EPA proposed to rescind its
 m          emission control regulations proposed on June 14, 1972,  for 17 AQCR's
            and approve the State submitted control strategies for the attainment
 •          of N02 standards within these AQCR's.  However, disapprovals  of nitrogen
            oxides control strategies were retained for New Jersey-New York-Connecticut
 |          and the Wasatch Front AQCR's.

I

I
.                                         A-7  v

-------
                                                                  .
were encouraged to rescind such NO  control regulations.   This action
                                  X
                                                                                  I
EPA held in abeyance the proposed regulations in these two AQCR's                 •
until  final decisions could be made on the classification of these
AQCR's.  The Federal Register notice also indicated that States which             I
had submitted NO  regulations  in AQCR's now classified Priority III
                                                                                  I
                                                                                  |
was taken since the regulations were developed on an inaccurate data              •
                                                                      *           I
base and current valid data did not support the need for such control.
     Thirdly, EPA oroposed to change 51.14 (i.e., the requirements for            •
approvable NO  control strategy) so as to require an explicit demon -
             '                                                                     •
stration that the national standard for NOV would be attained in Prior-           |
                                          X
ity I AQCR's.  States would still be allowed to take credit for any NO            B
                                                                                  I
reductions to be obtained through the FMVCP and any TCP necessary for             m
                                                                                  I
controlling CO and/or 0 .  Further, the Preamble to the proposed changes
                       X
to Part 51 indicated that if a State could demonstrate NO  reductions
that may result through the use of hydrocarbon emission control, then             I
such reductions could be considered in the demonstration of attainment            _
of the NAAQS.                                                                     •
     On May 8, 1974, at 39 FR_ 15344, the Administrator promulgated                •
these three proposals with one exception.  During the comment period,
additional data had become available for the Baltimore AQCR which                 I
marginally indicated that that AQCR should not be reclassified Priority
III.  The data, however, were not conclusive that the AQCR should be              •
designated Priority I.  Hence, Baltimore was grouped with Denver,                 •
Salt Lake City and New York as AQCR's which required additional infor-
mation prior to final reelassification.                                           I
*To date there have been few submittals for rescinding of NO  control             •
regulations.                   .                                                   •
                              A—8

                                                                                  I

-------
 I
 •               As  a  result of the  promulgations,  control  plans  were
             needed for the  two  Priority  I  AQCR's  (e.g., Los Angeles  and Chicago).
 •          Hence the  State of  Illinois  was  required  to submit within 4 months
             a demonstration that the approved  control  strategy for the Metropolitan
 •          Chicago  AQCR was adequate to attain and maintain  the  national  standard
 •          for nitrogen oxides.   With respect to the Los  Angeles AQCR, EPA  had
             previously disapproved California's control strategy  for nitrogen oxides,
 •          carbon monoxide and photochemical  oxidants, and promulgated a  transpor-
             tation control  plan.   On February  6,  1974, the State  of  California
 •          submitted  a plan revision for Los  Angeles  which provided a transportation
 •          control  plan and a  control strategy for nitrogen  oxides.  At the time
             of the Federal  Register  action,  EPA (Region IX) was reviewing  the plan
 •          to determine its adequacy in fulfilling the requirements of the  revised
             §51.14 to  demonstrate the attainment  and  maintenance  of  the nitrogen
 I          oxide standard  for  Los Angeles.  Hence  no further control strategy was
 •          required for Los Angeles at  that time.  In the July 12,  1976,  Federal
             Register  EPA called for a revision of  the SIP NO control strategy for
 I          Los Angeles.

 I

 I

 I

 I

 •                                         A-9

I

-------
  I
  •                               SECTION B
                   CURRENT STATUS OF AMBIENT N02 MEASUREMENT  METHODS

                  Since the announcement that the Jacobs-Hochheiser method was poten-
  I          tially inaccurate, EPA has used other nitrogen dioxide measurement tech-
             niques in conjunction with the routine activities of the Continuous Air
  •          Monitoring Program (CAMP), the National  Air Surveillence Network (NASN)
  •          and the Community Health and Environmental Surveillance System  (CHESS).
             Data from these methods, as well as from laboratory investigations have
  I          been used to investigate the various methodologies.  Four 24-hour bubbler
             methods have been operated at approximately 200 NASN sampling sites for
  |          various periods during 1972-73-74.  These include:   (1)  sodium arsenite
 •          (orifice), (2) sodium arsenite (frit), (3)  the triethanolamine- guaiacol-
             sulfite (TGS), and (4) triethanolamine  (TEA)  methods.  In 1972,  continu-
 •          ous chemi luminescence instruments were placed in 41 AQCR's  and  operated
             for approximately one year.  Additionally, 20 chemi luminescence
 |          instruments were operated in various AQCR's with three additional
 —           instruments operated in Los Angeles under the CHESS network.
 ™           Continuous Colorimetric (Saltzman) have  been used at each of  the six
 •           CAMP sites.   In addition to these EPA sponsored  monitoring  projects,
             the state  and local  agencies have begun  to expand the  NO 2 ambient moni-
 |           toring networks with various valid monitors.
 M                In addition to  collecting NO 2 information by various methodologies,
             work has  continued to determine a new reference  method for  N0£  to replace
I           the Jacobs-Hochheiser method.   Since  the  major  problem  with  the  Jacobs-
             Hochheiser method was the variable  collection efficiency  of  the  absorbing
I
I

-------
                                                                                   I
reagent, six alternate absorbing methods have been examined.  These                I
methods have undergone two independent studies at the Environmental
Monitoring and Support Laboratory.                                                 I
     As  a  result  of these  studies,  the  chemiluminescence measurement               •
 principle  and  calibration  procedure was  proposed  in  the Federal
 Register on March 17, 1976,  as  the  basis for the  new reference method.   The       |
 chemiluminescent  technique was  selected over the  manual-type candidate  methods
 primarily  because  analyzers based  on this principle would  have the                •
 capability of generating  continuous, real time data rather than integrated        •
 data  representing  24-hour time periods  as in  the case with  the Arsenite
 and TGS manual methods.   Technical evaluations and comments  from  the              I
 monitoring community were also considerations in the selection.   It
 should  be  noted  however that for determining  compliance to the National           |
 Ambient Air Quality Standard for NCL -  an annual arithmetic  mean  -                mm
 integrated 24-hour bubbler  measurements  are adequate.
     In addition, two 24-hour bubbler methods were found to be reliable            |
and capable of producing valid air quality data.   These are the TGS and            _
sodium arsenite orifice methods.  These two bubbler methods will be tested         ™
for equivalency as  soon as a reference method is  designated.                       •
     Data collected  under  proper operating conditions for these three
methods, i.e., chemiluminescence, TGS, and arsenite orifice can be used            J
directly in development of NO  control strategies.  Additionally, there             _
                                                                                    I
are other methods in  field use which are thought at this time.' to be                 m
                                5-2
I
I
I

-------
 I
 I          capable of producing  valid  air  quality  data  under  the proper operating
            conditions, i.e.,  TEA,  sodium arsenite  frit  and continuous  Saltzman
 I          colorimetric.   However,  the likelihood  of  these methods providing valid
 _          data for an annual  average  is not  as  great as with the sodium arsenite
 *          orifice, TGS,  or chemi luminescence methods.  Therefore care should be
 •          taken to assure that  the air quality  data  used for the control study is
            valid.   If bubbler methods  are  to  be  used  in SIP networks,  the use of
 •          arsenite orifice and  TGS bubblers  should be  encouraged.   If continuous
            methods are to be  employed, chemi luminescent analyzers should be encouraged
 •          although data  collected  with Saltzman colorimetric analyzer can be used
 •          if it is judged valid.   (See Table B-l.)
                 In the case of the  TEA method,  it  was found that the collection effi-
 •          ciency  is low  (around 50% with  an  orifice) and that  a frit  is necessary
            to  obtain a more  desirable high constant  collection efficiency of 80%.
 •          Although data  from this  method  would  be acceptable for use  in strategy
 •          analysis, other methods  are available which  have high constant collection
            efficiencies without  the use of a  frit.  The frit  is undesirable for the
 I          following reasons:   it  can  become  clogged  which would result in inaccurate
            flow measurements;  the  use  of pre-filters  to capture particulate would
 •          interfere with SO^  measurements if an N02/S0? sampling train was being
 •          used; and it is more  expensive.
                  In the case  of  the sodium arsenite frit method, it was determined
 •           that the frit increased the collection efficiency by only  approximately
             5%.  Because  of the  problems mentioned above with the use  of frits, this
•           method should be  discouraged,  although data already collected under proper
             operating conditions can be used  for emission control strategy analysis.
I
I
                                            B-3

-------
                          TABLE  B-l

               N02 AMBIENT MEASUREMENT METHODS
   Measurement Method
     (Method Code)
   Instrumental

   (11)  Modified  Saltzman
         Colorimetric
   (12)  Saltzman  Colorimetric

   (13)  Coulometric

   (14)  Chemiluminescence

   Bubblers .

   (71,  81,  91) Jacobs-Hochheiser

    (72,  82,  92) Saltzman  Bubbler

    (84)  Sodium Arsenite Orifice

    (94)  Sodim Arsenite -  Frit

    (95)  TEA

    (96)  TGS
         Comment
Data can  be  used with Caution *

Data can  be  used with caution

Data can  be  used with caution

Proposed  Federal Reference  Method
Data can  be  used



 - Data must not be used

-  Data  must not be  used

Candidate Federal  Equivalent Method
  Data can be used
 Data can  be used with caution

 Data can be used with caution

Candidate Federal  Equivalent Method
  Data can be used
*User should be aware  of  the  problems associated with the method and be
 assured that proper procedures were used in collecting data.
                             B-4
I
I
I
I
I
1
I
 1
 I
 I
 I
 I
 I
 I
 I
 I
 I

-------
 I
•                   In  the case of continuous colorimetric (Saltzman) analyzers, results
             of  tests indicate a method bias, slow response time (about 15 minutes) and
I           negative ozone  interference for certain monitors.  Because of these problems,
_           the use of chemi luminescent analyzers should be encouraged.  However, data
™           obtained from analyzers using this measurement principle may still be valid
•           for use in emission control strategy analysis for the following reasons:
                   1.  Since  the ozone interference noted in some monitors is negative,
•           any NOp values  obtained will  tend  to be  conservative.
                   2.  The ozone  interference is  significant only at  high  OgrNCL  ratios
•            (32%  negative  interference at 3:1   O-^NCk  ratio) which  occur over a  limited
•           part  of the day and  usually over one or  two seasons of  the year.   Thus,
             the impact of  this  interference on annual  averages of NCL should be
•           small  in many  areas of the country.
                   3.  A slow response time is not important when only annual averages
•           are of interest.  The impact  would be insignificant on  the annual average.
•           However, short-term averages  (e.g., 1-hr.) could be affected significantly.
                   4.  Some  users of analyzers (i.e.,  California/Los  Angeles) using
•           the colorimetric principle claim they have been unable  to detect significant
             ozone interferences.  Thus, it is  possible that specific models may not
I           be  as  prone to  ozone interference  as others.
•                 Any data  collected from  instruments using the Jacobs-Hochheiser proce-
             dure  should not be  used for strategy analysis.  Anyone  using Jacobs-Hoch-
•           heiser bubblers should be encouraged to  switch to the Sodium arsenite
             orifice or T6S  procedure as soon as possible.  A more detailed discussion
|           of  ambient NCU  measurement method  can be found in Comparison of Methods
              for Determination  of Nitrogen Dioxide  in Ambient Air     (EPA-650/4-75-023) .
I
I
                                                B-5

-------
     The following section contains a more complete discussion  of each
method.
                      N02 MEASUREMENT METHODS
                                                                                   I

                                                                                   I

                                                                                   I
                                                                                    I
1.  Sodium Arsenite Procedure (ARS),  orifice- Bubbler  (Method No.  84)
    Principle and Applicability                                                     •
         Nitrogen dioxide is collected by bubbling ambient air through  a  sodium
hydroxide-sodium arsenite  solution to form a stable solution  of sodium nitrite.     •
The nitrite ion (N0£) produced during sampling is  reacted  with phosphoric acid,
sulfanilamide, and N-l-(naphthyl)  ethylienediamine  dihydrochloride to  form an azo-   •
dye and then determined colorimetrically.                                           •
         The method is applicable to the collection of 24-hour samples  in the
field and their subsequent analysis in the laboratory.                               I
    Interferences
         Nitric oxide (NO) is a positive interference.  The presence of NO  can       I
increase the NO ?response by 5 to 15 percent of the N0£ sampled.                     •
         The interference of sulfur dioxide is eliminated by converting it to
sulfate ion with hydrogen perioxide before analysis.                                 •
    Evaluation
         The method when followed is a precise procedure for measurement of          I
NOg on a 24-hour average basis, and is sufficiently accurate provided the            •
average 24-hour NO and/or C02 concentrations do not exceed 310 J4g/m  and/or
500 ppm, respectively.  The probability of these concentrations being exceeded       •
in ambient air is low (less than 5%).  Data from this method are considered
valid and can be used as the basis of a control  strategy.                             I
2.  TGS-ANSA Procedure  - Bubbler (Method No. 96)
                              B-6
I
I

-------
I

I         Principle and Applicability
                Nitrogen dioxide  (NOp) collected by bubbling air through a solution of
•      triethanolamine  (T), 0-methoxyphenol  (guaiacol)  (G), and sodium metabisulfite  (S)
•      The nitrite ion  (N02) produced during sampling is determined colorimetrically by
        reacting the  exposed absorbing  reagent with  sulfanil amide and  8-anilino-l-
•      naphthalenesulfonic acid ammonium salt  (ANSA).   The method  is  applicable  to
        the collection  of  24-hour samples in  the  field and subsequent  analysis  in the
m      laboratory.
•      Interferences
             At a  NCL  concentration  of  100 jug/m3, the following  pollutants, at  the
•      levels  indicated do not cause interferences:  ammonia, 205  jug/m3; carbon
        monoxide,  154,000 >jg/m3, formaldehyde,  750 /jg/m3; nitric oxide,  734 jjg/m3;
I
I
                        33                              3
        phenol, 150 jug/m ;  ozone,  400 yug/m ;  and sulfur dioxide,  439/jg/m .
                  A  temperature  of  40°C  during  collection  of  sample  had  no  effect
         on  recovery.
I           Evaluation
                  The  method  is  an  accurate,  precise  procedure  for measurements  of  NO,,
•       in  ambient  air when  the specified  analysis procedure is  followed closely.
f       The method  has more  than adequate  sensitivity  for ambient measurement for
         24-hour sampling  periods.   However,  the method does  not  appear  to  be sensitive
•       enough  for  shortfeterm sampling.  Data  from this method are  considered valid
         and can be  used as the  basis  of a  control strategy.
|       3.   Chemiluminescence Method  -  Instrumental    (Method  14)
•           Principle and Applicability
                  Atmospheric concentrations  of nitric  oxide  (NO) can  be measured by
•       the chemiluminescent reaction of ozone (03)  with  NO  at reduced  or  near
         atmospheric pressure.   Nitrogen  dioxide (NOg)  is  measured as  NO in the  system
I

-------
                                                                                      I

after conversion of NOg to NO.     Air samples are drawn directly into the
analyzer to establish a NO response; then a switching valve directs the sample        •
air  through the converter where the N02 is converted to NO.  The photomultiplier
measures the light energy resulting from the chemiluminescent reactions of NO         I
and 03.  By subtracting the NO signal  from the NO+N02(NOX) signal, the amount of      *
N02 is determined.  The subtractive process is accomplished electronically.
Total time for both measurements is less than 1  minute.                               Q
         The method is applicable to the measurement of NOg, at concentrations         m
in the atmosphere ranging from 9.4 to  18,800 ug/m3 (0.005 - 10'ppm).                   *
         Interferences                                                                jl
         The chemiluminescent detection of NO with 0^ is not subject to inter-
ference from any of the common air pollutants, such as Og, N0£, carbon monoxide       •
(CO), ammonia (NHg), or sulfur oxides (SOX).                                          _
         When the instrument is operated in the NO* mode, any compounds that          •
may be oxidized to NO in the thermal N02 converter are potential interferents.        •
The principal compound of concern is ammonia; however, this is not an inter-
ferent for converters operated at less than 330°C.  Unstable nitrogen compounds       •
such as peroxyacetyl nitrate (PAN), organic nitrites,  decompose thermally  to          ^
form NO and may represent minor interferences in some polluted atmospheres.            •
         Evaluation                                                                    •
         The chemiluminescent method is a precise and accurate procedure for
measurement of NO. in ambient air when used by an experienced operator.  The           •
method has more than adequate sensitivity for ambient measurements.  Data  from this
method are considered valid and can be used as the basis of a control strategy.        •

                                                                                       I
                                   B-8                                                 •

-------
I
 I

 "     4.   Colorimetric Method  (Saltzman) - Instrumental  (Method  11)
 •         Principle  and Applicability
                This  method  is  based on a specific reaction of nitrite ion (NOg) with
 •     diazotizing-coupling  reagents.  The absorbance of  the azo-dye is directly
 m     proportional to the concentration of N0£ absorbed.
 •              This  method  is  applicable to  the measurement of N02 at concentrations
       in  the ambient air from  18.8 to 1880 ^ig/m3  (0.01 -  1 ppm).
           Interferences
•              Interferences from other gases that might  be found in the ambient air
       ha've been reported to be negligible  ;  however, most interferent studies  have
 •     been done on manual  procedures  and may not  be  applicable to continuous methods.
 ft     Recent studies indicate  that ozone  (0^) produces a  negative interference
       as  follows:   ratio of 0^ to N0? 1:1  =  5.5 percent,  2:1 = 19 percent,  and
 •     3:1  = 32 percent.
       Evaluation
»          The results  of  the  collaborative  test  demonstrates a  collaborator
•     dependent method  bias which cannot be  quantitated.  The method has a  slow
       response time  and possesses a negative ozone interference.  The method does
•     have an acceptable lower detectable  limit and  adequate precision.  Until
       the problems  discovered  in the  collaborative test  are resolved, additional
m     monitoring using  this method should  not be  initiated.  However, after reviewing
•     data available from  this method,  it  may be  found satisfactory for control
       strategy development.
•     Status of Selection of New N02  Reference Method
                As a  result  of  these tests, the chemiluminescen ce measurement
I     principle and  an  associated calibration procedure  was  proposed  as  the basis

I                                         B-9

-------
                                                                                  I
for a method to supercede the  original  reference  method.   The  chemilumi            •
nescent technique is recommended over the manual-type condidate methods            ^
primarily because analyzers based on this principle would have the capa-          Ij
bility of generating continuous, real time data rather than integrated
data representing 24-hour time periods as in the  case with the arsenite            p
and TGS manual methods.  Technical evaluations and comments from the              ^
monitoring community were also considerations in  the selection.  It               *
should be noted however that'for determining compliance with the National          •
Ambient Air Quality Standard for NCL - annual arithmetic mean- integrated
24-hour bubbler measurements are adequate.                                        V
     The continuous chemiluminescence measurement principle and calibra-
tion procedure were proposed in the Federal Register on March 17, 1976,            *
as the new reference method.  This proposed action specified only a               A
measurement principle and calibration procedure,  not a reference method
per se.  For a specific analyzer to be designated as a reference method            m
for N0?, it would be required to utilize the measurement principle and
calibration procedure, meet all specifications and other requirements of          |
Part 53 (i.e., EPA reference and equivalency requirements that will also          M
be promulgated shortly) and be designated as a reference method under
provisions of Part 53.  Analyzer manufacturers would test their own respec-       •
tive analyzers against the specifications and requirements and then would
submit the results to EPA.  Analyzers satisfying all of the Part 53               J
requirements would be designated as reference methods.  It would, there-          «
fore, be possible to have several reference methods for NCL.  In addition,
other methods or measurement principles will be designated as equivalent          •
methods.  A three-month period is being allowed for manufacturers to
best their instruments and submit them with the test results for reference
                                  B-10
I

-------
 I
 I
 I
 I
 I
 I
 1
 1
 I
 I
 I
 I
 1
 1
 I
1
t
I
Method designation.  If no instruments are submitted in that period,

EPA will designate an instrument which EPA itself will  have tested and

found satisfactory as the reference method.  The FEDERAL REGISTER

action schedule needed to accomplish these tasks is outlined below.

             Schedule for Establishing NCL Reference Method

                      Action
Date

3/17/76




3/17/76

10/76
2/77
3/77
Propose continuous chemiluminescence measurement principle

and calibration procedure (40 CFR Part 50).

Propose reference and equivalency requirements (40 CFR Part 53),

Promulgate measurement principle and calibration procedure;

promulgate reference and equivalency requirements.

Designate reference methods (40 CFR Part 50) and identification

of acceptable commercial instruments.

Designate equivalent methods (40 CFR Part 53).  (Arsenite and

TGS 24-hr, bubbler methods are expected to be designated as

equivalent methods.)
                               B-ll

-------
 I

 I                                   SECTION C
                   N02 FORMATION PROCESSES AND CONTROL STRATEGY  MODELING
         Emissions of NO  and NO- Formation
                        A       C-


 J            Most man-made sources of nitrogen oxide, NO  , emit primarily nitric



 _       oxide, NO.  Some point sources, such as nitric acid plants and TNT



 *       plants,  however, directly emit mostly nitrogen dioxide, N02Jinto the



 •       atmosphere.  The reaction mechanism for the conversion of NO to N02



         conversion  is complex and is a function of many factors including the



 g       hydrocarbon concentrations, hydrocarbon reactivity, ultraviolet radiation



         and ambient temperature.



 ™            The importance of hydrocarbons in the conversion of NO to N02



 •       is the photochemical production in the air of organic radical species



 ^       and ozone which oxidize the NO to N02.  Ultraviolet light acts both to



 1       photochemically dissociate N02 to NO and at the same time to help



         produce  the species that oxidize NO to N02.  As a result, ambient air



 *       never has just NO or just N02, although summer afternoon air often has



 •       10 to 15 parts of N02 per part of NO.  The conversion of NO. to N02 is



         slower in the winter than in summer because of lower temperatures.



1       A parameter that has been identified in laboratory studies as important



         in the conversion process is the hydrocarbon to NO  ratio.  It appears


 I                                                         '
 9       that if  the ratio is reduced by reducing the hydrocarbon emissions



I         more than the NO  emissions, the peak N0~ concentrations will decrease
                         x                       t


         but the  nonpeak N02 concentrations may actually be increased due to the



 I       lessening of the extent of removal processes with the hydrocarbons.
I

-------
It is not known how the 24-hour and annual  average concentrations will  be
affected.  Although insufficient data is currently available to require            I
consideration of the hydrocarbon to NO  ratio in control  strategy
                                                                                   I
development work, the hydrocarbon reduction associated with the oxidant            m
control strategy may become of interest in  the future and eventually may           M
need to be considered with respect to its possible impact on the N02
control strategy.                                                                  I
     Under most conditions, NO is mostly converted to N0~ within a few
                                                                                   •
hours.  During this period, NO  emitted into the atmosphere is constantly          (
dispersing while the N02 is forming.  In an urban area this fact can allow
a portion of the NO  emitted from tall stacks to be brought to the ground
                   A
and a portion of the NO  emitted from motor vehicles to disperse upward
                                                                                   A
before the N0-N0? conversion is completed.  As the NQ9 is formed in large
                                                                                    I
urban areas, it becomes rather uniform in concentration in relation to              |
the area due to the significant NO  emissions throughout the urban area.            m
                                                                                    I
For the 24-hour average and for the annual average, sharp NO^ concen-
tration gradients are therefore not observed in urban areas in contrast             I
                                                                    *\               ^
to the situation for directly emitted pollutants such as CO and S0?.
                                                                                    •
     Isolated point sources outside of urban areas, whether large or                jjf
small NO  emitters, have their greatest impact near the source with                 m
        x                                                                           |
relatively less impact on distant cities where NO  attainment problems              w
                          : ~ ' '   ~                 /\
are generally experienced.  Generally, most isolated fossil fuel -fired              •
power plants have a minor local impact and a negligible impact on annual
average NO- concentrations at a distance greater than 20 to 30 miles.               |
The time period required for NO-NOp conversion and transport to a                   ~

                                                                                    I
                                 C-2
                                                                                    I

-------
I
I        metropolitan area allows for diffusion of the NCL to such an extent
          that  its  impact on  the  urban area  is minor.  Thus, sources of NO
£        emissions  20 or more miles distant from the  fringes of an urban area  generally
—        need  not  be considered  as an important emission source in relation to the
™        urban area, even though their emission rates may be large.  Large emission
•        reductions from such isolated sources usually will not be  effective
          in  reducing IW^ concentrations  in  the urban  area.  Other factors such
I        as  wind persistence, topographical  features  restricting transport in
_        certain directions, etc., should also be considered in analyzing NO  - N0?
1
"        source receptor relationships and  defining  "isolated" sources.
•              Natural background concentrations of N02 resulting from bacterial
          and plant  actions should also be considered  in strategy development.
|        Such  concentrations are generally  about 8 yg/m  (.004 ppm)2 annual
                                                              *
          average.

                                CONTROL STRATEGY MODELING
|              A key element  in the evaluation of a control strategy is an
«        adequate  methodology for relating  pollutant  emissions to ambient air
          quality.   A commonly used technique is an atmospheric simulation model
1
I
which is a mathematical description of the pollutant transport, dis-
persion and transformation processes that occur in the atmosphere.
In its simplest form, such a model relates ambient pollutant concen-
trations (x) to pollutant source emissions rates (Q) and a background
           concentration  (B).
1              x  =  KQ  +  B

I
I
                                  C-3

-------
                                                                                 I
The variable K is a function of atmospheric conditions and the spatial           •
relationships between a source and a receptor.3
     With the aid of a simulation model, it is possible to estimate              |
systematically the variations in pollutant concentration which would             m
result from alternative degrees and types of emission control.  If each          •
control strategy can be stated in terms of specific emission reductions,         9
then a simulation model can be used to investigate the cost effective-
ness of each strategy.  Although simulation models may not be capable             •
of indicating the air quality impact of individual control strategies
with precision, simulation models provide a measure of the range and              ™
relative significance of air quality changes which may result from                •
various strategies.
     The simplest of the models used to project air quality is the                I
proportional or rollback model.  In the past this model has been used
for NO  control strategy review and development for urban areas.  It is           9
recommended that this simple model along with measured air quality                flj
data continue to be used as the basis for NO  planning.  While other
                                            X
models may be applicable to special cases, such as isolated point sources,         M
or may attempt to explicitly account for the photochemical production
of NOp, such models have not been adequately validated at this time.               m
     The proportional model assumes that the dispersion parameter (K)              ft
does not vary with time or with the source-receptor relationship and that
changes in NO  emissions will be uniform across the area.  Thus the                I
relationship of emissions  (Qp) and air quality (xp) at some future time


                                                                                   i
                                                                                   I

-------
  I


  •         to  base year  emissions  (Q, )  and  air  quality  (XT)  can  be expressed

            by  the following proportionality which  accounts  for the natural  back

  Ji         ground NO^  concentration  (B) .


                 X2 - B  0
I


I
 H              Fundamentally,  the  rollback  model  assumes  that  there  is  a  direct



 —         cause and  effect  relationship  between  the  rate  of  emission of the  pollu-



 *         tant  and its  concentration  in  the atmosphere.   If, for example, the rate



 •         of emissions  is reduced  by  95  percent,  it  is expected  that the  non-



            background component of  atmospheric  concentrations will  be reduced by



 •         95 percent.   The  use of  this linear  relationship does  not  imply that



 _         the chemical  relationships  leading to  NC^  formation  in the atmosphere



 '         are linear.   It is,  therefore, not necessary to know what  percent  of NO
                                                                                   /\


 4         is converted  to NCL.   The implicit assumption  is that  the  ratio between



            emitted NO and ambient  N0? is fixed and  that  it will  not  change from
                      A.               C.


I            year  to year  as NO   concentrations change.
                             X


 _               The proportional  model can be used to determine the reductions



 ™          in NO emissions  which are  necessary to reduce  N0? ambient concentrations
                 /\                                          t
•          from XT  to  xo  if no change  in  N02 background occurs.   To calculate



            the  percent reduction in  NO emissions,  R, the proportional  model
                                       A


I          can  be rewritten in the rollback form,  as follows:
m                   ^i    v?           xi    x?
•               R =  -i-^—— x 100 =       b   x 100
•                      QI             x-|  - B

            where XT  = SIP design  value (representative annual  average N09 con-

                   I'                                                      *

            centrations  in base year).
C-5

-------
                                                                                   I
      B = N02 background concentration (8 yg/m )                                   I
     X2 = C = NAAQS for N02 (100 yg/m3)
      R = Percent reduction in NO  emissions required                              *
                                 J\
      The rollback model is applicable to annual N02 concentrations                •
on an urban area basis for which appropriate data are available.  Input
to the rollback model requires total area-wide emissions for the base              •
year and for the future year of interest.  An annual NOp concentration
representative of air quality for the area of interest is also                     9
necessary.  It should be noted that the proportional model can only be             <•
used to estimate concentrations at sites where representative air
quality data are available.  However, because of the small NOp gradients           V
observed in most urban areas, this limitation becomes of much less
importance for N02 than for other pollutants.                                      m
     Because of the number of different types of sources which emit                m
NO  , an expansion of the simple rollback equation has been made.  This
expansion is called Modified Rollback  (See Appendix A - Modified                   V
Rollback).  Modified Rollback is a technique for considering a variety
of NO  source categories and growth factors.  It can be expressed as               V
              N                   N                                                g
     —-T~B"  i=l    'base year = ^  ^i rfuture                                  •

where
     G = a growth  and control factor,  i.e., the  ratio of  NO  emissions             •
         at or after the attainment date versus  the NO., emissions
          ...	,,__. ,

                                 C-6
                                                                                   I

-------
 I
 •               N  =  the  number of source  categories,
                  i  =  a  particular  source category, e.g.,  light-duty  vehicles,
 V                   trucks,  power plants  and  other  stationary  sources, etc.
I            In  cases where the area-wide NO  emissions  are contributed  by  a  variety
            of  source  types with differing  emissions, growth  rates  and  applicable
 •I         controls,  the  modified  rollback model  permits  a consideration  of a
            variety  of control  strategies.
 |               To  apply  this technique, the left side of the equation is evaluated
I            with  available data to  determine an allowable  NO  emission  rate.  The
                                                           X
            right side of  the  equation  is then  evaluated for  various  control  strategies
 H          until  a  strategy which  demonstrates attainment is developed.   Growth
            rates for  mobile sources and for stationary combustion  sources can
 |          usually  be obtained from local  planning agencies. Future emission
^          reductions for mobile sources can be estimated from  Supplement 5 to AP-42.
            Expected emission  reductions for stationary sources  depend  on  new source
II          performance  standards and local regulations for NO   emissions  on the
            date  that  these regulations take effect.
Q               The rollback  models are applicable anywhere  for which  there are
«          basic data on  area-wide emissions and representative air  quality for
™          a particular base  year.  The simple rollback model can  be applied
V          with  hand  calculations  and  is widely used.   Modified rollback  has
            been  computerized  and documented.  A computer  program and associated
I
I
I
            documentation on the "Modified Rollback Computer Program" have been
            made available to all  EPA Regional  Offices.
                                            C-7

-------
                                                                                  I

                            APPLICATION                                           I
     Figure C-l presents projections and trends for nitrogen dioxide              •
for Los Angeles and Philadelphia (Camp Stations).  These annual average
N02 concentrations were developed using the modified rollback technique.          •
In general, Figure C-l demonstrates that the modified rollback model
and assumptions used with it provide an adequate representation of the            »
actual air quality trends.  The projections are smooth curves, whereas            m
the measured air quality may change randomly from year to year because
of meteorological factors.  Any deviation between the projected values            •
and the measured air quality may be due to errors in estimating and
projecting emissions and changes in air quality.                                  *

                         OTHER MODELS                                             |
     Because of the limitations of existing N0-N02 modeling techniques,
MDAD, OAQPS is continuing to review available models to assure the                "
best "state of the art" models are made available for N02 control                 *
strategy review and develonment work.  The proportional model previously
discussed  is currently the method which is recommended for control                V
strategy development work.  If other superior NO  models are identified
                                                x                                 i
by future  OAQPS reviews, they will be made available to the Regions as            •
soon as possible.  AQDM, COM, or other models may be used when evaluating         
-------
I
I
I
I
1
I
180
      160
      140
   tm
   c
   o
   £  .20
   4J
   C
   0.1
   o
   Q)
   cn
I
 f
I
I
r
    I™
   2  100
i
i
i
i
i
t
i
       40
                                  FIGURE  C-l

          OBSERVED AIR QUALITY VS. MODIFIED ROLLBACK PROJECTIONS
             O

             O
               Los Angele
                     Philadelohia
                    1964       1966

                        Parameter
                                    1968      1970
                                         YEAR
1972
1974
               Observed N02 Concentrations  (Modified Saltzman Method)
               Projected N02 Concentrations (Modified Rollback Model)
                                      C-g

-------
                                                                              I
                      REFERENCES                                               •
1.   Martinez,  E.  L.,  and  N.  C.  Possiel,  "Report of N0? Distribution            j|
    in Cities" Memo,  October 10,  1975.
2.   Air Quality Criteria  for Nitrogen Oxides, AP-84, pp. 3-1 (1971).           •
3.   Appendix A-40 CFR Part  51.

                                                                              I
                                                                              I
                                                                              1
                                                                              I
                                                                              I
                                                                              I
                                                                              1
                                                               >,
                                                                              t
                                                                              I
                                                                              I
                                                                              I
                                                                              t
                                                                              I
C-10

-------
 I
 •                        CONTROL OF OXIDES OF NITROGEN
 I
                          SECTION D
                          - OXIDES OF
                   FOR STATIONARY SOURCES

                      Table of Contents
                                                                   Page
BOILERS AND HEATERS                                               D- 1
 fl           Utility Boilers                                                 D- 2
               Tangenti ally-fired boilers                                    D- 3
 |             Front-wall firing furnaces                                    D- 4
 —             Horizontally-opposed firing furnaces                          D- 4
 ™             Cyclone furnaces                                              D~ 4
 •             Split or divided furnaces                                     D- 4
             Commercial, Residential, and Industrial  Boilers (CRI)           D- 5
 I         COMBUSTION MODIFICATIONS                                          D- 7
 ^           Low excess air combustion (LEA)                                 D- 7
 ™           Off-stoichiometric or staged combustion                          D- 8
 fl           Flue gas recirculation (FGR)                                    D- 8
             Water or steam injection                                        D- 9
 J           Preheat reduction                                               D- 9
 —           Firebox enlargement                                             D- 9
 •           Derating                                                        D- 9
 •           Burner designs                                                  D- 9
             Costs of Combustion Modifications                              D- 12
 I         FLUE GAS TREATMENT (NO )                                         D- 13
 ^v                               X
— ,           Dry Flue Gas Treatment                                         D- 13
•
"           Wet Flue Gas Treatment                                         D- 15
•         GAS TURBINES                                                     D- 16
           STATIONARY INTERNAL COMBUSTION ENGINES                           D- 18
I

-------
                                                                                 I
INDUSTRIAL PROCESSES                                           D-19              |
  Nitric Acid                                                  D-19              _
  Catalytic Decomposition                                      D-19              *
  Scrubbing                                                    D-20              •
  Molecular Sieves                                             D-20
  Extended Absorption                                          D-21              £
  Other Chemical Processes                                     D-21              _
PETROLEUM AND NATURAL GAS PRODUCTION                           D-23              •
METALLURGICAL PROCESSES                                        D-23              •
CEMENT, LIMESTONE, CERAMIC, AND GLASS PRODUCTION               D-24
OTHER STATIONARY SOURCES                                       D-24            •.  §
SUMMARY OF NOV CONTROLS                                        D-25              m
             x                                                                 ...|
GLOSSARY                                                       D-27             , •

                                                                                 I
List of Tables                                                                   •'
List of Figures
                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

-------
•                                     List of Tables
I
I
           Table D-l.   Analyses  of Typical U. S. Coals and Lignite
           Table D-2.   Analyses  of Typical Fuel  Oil
           Table D-3.   NOV Emission Levels from  Uncontrolled Utility Boilers
                        A
 •                    Compared  to  the New Source Performance Standards
           Table D-4.   Typical Baseline Emission Levels From Commercial  and
 •                    Residential  Heating
 •i        Table D-5.   NOX Levels  and Typical NOX Reductions with Combustion
                       Modification to Utility Boilers
 •        Table D-6.   Summary of  Combustion Modification Techniques for
                       Large Boilers
 •        Table D-7.   Estimated Investment Costs for Retrofitting Low Excess
 •                    Air Firing  to Existing Utility Boilers
           Table D-8.   Major Flue  Gas Treatment  Plants in Japan Using Selective
 •                    Catalytic Reduction (Dry  Process)
           Table D-9.   Major Flue  Gas Treatment  Plants in Japan Using Wet  Scrubbing
 •        Table D-10.  Effectiveness of Combustion Modification on Gas Turbines

 I

 I

 I

 I

I

I

I

-------
                                                                                    I
                             List of Figures  ,                                      •

Figure D-1.   Tangentially Fired Boiler                                               |
Figure D-la.  Details of Tangentially Corner Firing Systems and Flame Pattern         .
Figure D-2.   Front Wall Fired Boiler                                                 *
Figure D-3.   Front Wall Fired Boiler                                                 W
Figure D-4.   Horizontally Opposed Fired Boiler
Figure D-5.   Schematic Drawing of Cyclone Furnace                                    J
Figure D-6.   Cyclone Fired Boiler                                                    ^
Figure D-7.   1973 Installed Equipment Costs of NOX Control Methods                   "
             for New Tangentially, Coal-Fired Units                                  •
Figure D-8.   1973 Installed Equipment Costs of NOX Control Methods
             for Existing Tangentially, Coal-Fired Units                              J
                                                                                  /
Figure D-9.   Typical Gas Turbine Base Load NOX Emissions                        '      m
Figure D-lO.  Effectiveness of Water or Steam Injection in Reducing                    ™
             NOX Formation in Gas Turbines
I
I
t
I
I
I
t
 I

-------
 •                            CONTROL OF OXIDES OF NITROGEN
 *                                FOR STATIONARY SOURCES
 I
Control  technology for stationary  sources  can address NO  by
                                                       /\
 •        process changes or tail  gas treatment.   Process  changes tend to be
          specific to source characteristics.   Tail  gas  treatment has potential
 •        applicability to many sources  but except for nitric  acid  plants, its  use
          has been extremely limited to date.   The greatest activity in NO  control
 f
 •        has been with utility boilers and nitric acid  plants.
 •             Process changes are commonly termed "combustion modifications".  While
          still being refined, they are used widely for  large boilers and other
 •        combustion sources in the United States.  Flue gas treatment (FGT) systems
          are being investigated in the United States but most of the development
 m        work is being conducted  in Japan.
 •                                  BOILERS AND HEATERS
               Nitric oxide (NO) is formed during combustion either from thermal
•        fixation of molecular nitrogen in the combustion air (thermal  NO)  or from
          oxidation of chemically  bound nitrogen in fuels (fuel NO).  In the atmosphere,
•        NO reacts slowly *ri±h oxygen ID fora nitrogen  dioxide (N02).   The main factors
•        affecting NO formation in combustion sources are characteristics of the fuel
          burned, flame temperature, length of time the  combustion gases are subjected
 •        to peak flame temperatures  and  excess  oxygen.
          Effect of Fuel Nitrogen
                              II 2  3 4 5/
               Recent studies  ' * ' ' ' indicate that as much as half of the nitrogen
•        in the fuel (oil and coal) can be converted to NO.  It was also shown that
          the fraction of fuel nitrogen converted to NO  decreases with increasing
ff        nitrogen content even though the magnitude  of  the  NO  increases.  Excess air
          (oxygen) appears to  have  a  strong effect on fuel nitrogen conversion but con-
|        version is  relatively insensitive to  temperature.  Much of the U. S. supplies
I
                                        D-l

-------
                                                                                   I
of residual oil and coal are relatively high in nitrogen; therefore, it            H
is Important to give consideration to fuel  characteristics when discussing
combustion modifications.  Tables D-l and D-2 show the range of fuel  nitrogen       •
for various coals and fuel oil.
     An extremely wide range of devices can be classified as boilers or            P
heaters.  For this document, only a minimal review of boiler terminology           ^
is presented such that the reader can differentiate between those factors
that materially affect NO  emissions.  Many other publications treat               I
boiler and heater technology in depth.
     In broad categories, boilers and heaters can be differentiated by             Q
usage, fluids heated or vaporized, size, fuels burned, firebox design,             _
firetube versus watertube, by the use or non-use of air preheaters, and
                                                                                    I
by the manner in which they are constructed (field erected or packaged).
Many of these factors affect NO  emissions as do operational  characteristics
                                                                                    •
such as excess air, degree of air preheat, and firing rate.                         H
     For purposes of this paper we have segregated boilers and heaters into         ._
two groups which we term "utility boilers" and "commercial, residential,
and industrial (CRI) boilers".  There is some overlap since large industrial        V
boilers are grouped with utility boilers and the smallest utility boilers
are occasionally of the same design as CRI boilers.                                 |
Utility Boilers                                                                     _
     Utility steam generators and large industrial boilers are differentiated
                                                                                    I
from other types of boilers and heaters since they are much larger and produce
significantly greater concentrations and quantities of NO  than CRI boilers.
                                                                                    1
These large units (generally greater than 250 million Btu per hour heat input)      |
employ air preheaters such that firebox peak temperatures are about 500°F           ^
hotter than with CRI designs.  Also utility boilers are almost always field         *

                                  '. D-2                                             *

-------
I
I
            are  limited  but  by and  large  those  offered  for  new  units  reflect
            consideration  of NO  reduction  techniques.   Some  designs  inherently  produce
                               A
            more or less NO  .   Typical  new  utility  boilers  are  of 500 megawatts
                          A                                            *~
 I         erected, watertube  designs  as  opposed to packaged units  (built in the
 «         factory) typical  of CRI  installations.  Furthermore, essentially all
 *         U.  S.  utility  boilers  are manufactured by  four firms,  Babcock and Wilcox,
 I         Combustion  Engineering,  Riley  Stoker, and  Foster Wheeler.  Utility designs

 I

            (output) capacity (4.5 x 109 Btu per hour  heat input)  and most are
 •         coal-fired.  The  largest industrial boilers  are of  about 750 million Btu
            per hour heat  input.   Units of 100 million Btu per  hour  and greater tend


-------
                                                                                 I
     levels.  They are manufactured by Combustion Engineering.
     Figure 1 shows a typical corner-fired boiler.  Figure la shows              jj
     details of a corner firing system configuration and flame pattern.^
     Front-wall firing furnaces (Figures 2 and 3) are designed with              ™
     all burners firing horizontally from one wall normally considered           •
     the front of the furnace.
     Horizontally-opposed firing furnaces (Figure 4) are designed with           |
     rows of burners firing horizontally from the front wall and other
     rows of burners firing horizontally from the rear wall.                     "
     Cyclone furnaces (Figures 5 and 6) are a type of slagging furnace           •
     in which coal and combustion air are introduced in a tangential
     pattern.  Burning occurs at high heat release rates such that ash           I
     becomes molten and is tapped from the bottom of the boiler.  Cyclone
     furnaces require coal with ash of low softening point.  They produce        ™
     greater concentrations of NOX than almost any other design and for          •
     this reason are seldom installed at new sites.
     Split or divided furnaces are divided by a wall of steam or water           I
     tubes.  Such furnace* are -usually front-wall fired or horizontally-
     opposed fired.                                                              ™
     Uncontrolled emissions from utility boilers tend to be lowest for           •
tangentially fired units and highest for cyclone furnaces.  Other factor
being equal, NOX emissions are lowest for gas firing and greatest for            •
coal  burning.   However  because  of constraints on natural gas and fuel oil,
almost all  new  utility  boilers  probably will be fired with solid fuel.            ™
Ranges of uncontrolled  emissions are  listed in Table D-3 for principal utility    *
boiler designs.   The  relationship between  NO  concentration and the NSPS is a
                                           A                                      	
function of fuel  heat content and chemical makeup  (the latter governs the volume  •
of products of  combustion  generated by a unit weight of fuel).  The coal
                                 D-4

-------
           cited in  Table D-3 is of relatively high heating value (13,100 BTU per
 I        pound)  and  doesn't necessarily  reflect  the  coal  burned  in  the boilers
           at which  the  data were  measured.
 I        Commercial, Residential,  and  Industrial  (CRI)  Boilers
 I             Commercial and residential  boilers, small  and medium size industrial
           units,  and residential warm air furnaces are almost always  assembled at
 |        the factory and shipped to the user as a package.  For the  most part the
 _        boilers are of firetube design but the largest and smallest often  are of
 ™        watertube construction.  Until the recent oil crisis,  all except the oldest
 •        CRI boilers were fired with natural gas or fuel oil.
                 Because  of the  absence of air preheating and because of their smaller
 g         size (shorter residence time at high temperature) CRI boilers inherently
            produce less  NO  than their larger counterparts.  There have been only
 I
 *         limited efforts until recently to characterize emissions from CRI boilers.
 IB              It is  known that there are wide variations in CRI  firing rates and in
            burner maintenance  and adjustment. The firing rate and firebox characteristics
 I         probably have a strong effect on NO  emissions but the  influence of these
            factors has not been evaluated for the many CRI designs available in the
 "         United States.   Also there is little uniformity in such important design
 M         parameters  as firebox heat release rate.  However, in comparison to utility
            boilers,  CRI  units  probably are fired at lower rates, i.e., lower percentages
 |          of manufactures maximum load  rating;  this factor tends  to  reduce  NOX  emissions
            below those which would be predicted  from emission  factors.
 •
 •               In addition, CRI boilers normally receive less maintenance and operator
•          care than utility boilers such that combustion is less  complete and heat
            transfer is less efficient.  Precision adjustments, such as are necessary with
Q          many combustion modification techniques, are generally  not workable for rptrn-
            fitting CRI boilers.   The effect of maintenance and operator care on NOX emission
I
                                     Jx
D-5

-------
                                                                                I
in unclear.  Where combustion is incomplete, NO formation is likely             _
to be inhibited.  On the other hand, the extremely wide variation               ™
of excess air often observed at CRI boilers might produce more or               •
less NO  emissions.
       /\
     Baseline or uncontrolled emission levels for typical commercial             I
and residential heating boilers are listed in Table D-4.  These values
represent units of less than 100 x 10  BTU heat input, some appreciably         •
smaller.
                                D-6
I
I
I
I
I
I
I
I
1
I
1
I
I

-------
 I
COMBUSTION MODIFICATIONS
                Principal combustion modifications are measures that reduce maximum
           flame temperatures, minimize oxygen concentration, or reduce residence
 I        time at peak temperatures.  Combustion modifications include:  (1) low
           excess air (LEA), (2) off-stoichiometric combustion (OSC), (3) flue gas
 "        recirculation (FGR), (4) water or steam injection, (5) preheat reduction,
 •        (6) burner design, (7) firebox enlargement or revamping, and (8) derating.
                Of these options, LEA and OSC are the most frequently employed since
 •        they are applicable to most existing boilers, are less costly than other
           options, and represent no fuel penalty (in fact they can improve fuel
 •        efficiency).  FGR is the next most likely alternative particularly for
 •        new boilers or those already equipped with FGR components.  Options (4)
           and (5) present measurable energy penalties.  Option (6)--burner design—
 I        is in reality a broad area in which LEA, OCS, and FGR principles are
           usually employed within the burner.   Options  (7) and  (8) are corollaries
 •        with firebox modification usually applicable  to new boilers only; derating
 •        is a means of achieving the same  effect—less  heat release per unit volume —
           at existing boilers.  It should be pointed out that option (7) and  (8) are
 •        unattractive from an economic point of view.
                 Low excess air (LEA) combustion has been used successfully with  all
 •               fuels in a variety of furnaces.  By reducing oxygen  availability
                 at the burner(s), both thermal and fuel  NO  levels  are  reduced.
 ™               The degree of reduction is  a function  of furnace design and fuel
 •               characteristics as well as  excess air.   Practical  excess air levels
                 are limited by the formation of incomplete  combustion  products
|              (CO, partially oxidized hydrocarbons, and carbon).  Care must  be  taken
—              in reducing oxygen to avoid  unacceptably  low  levels where boiler  vibrations,
•              slagging, fireside corrosion, and in extreme  cases  explosions  (CO) can
•              be encountered.
•                                        D-7

-------
                                                                           I
Off-stoichiometric or staged combustion covers a wide- range of
techniques designed to limit the availability of oxygen during             I
combustion.  Two-stage combustion is a type of OSC which involves          _
reducing air through the main burners to about 90 to 95 percent            •
of stoichiometric and adding the balance of the combustion air             •
through separate ports beyond (usually above) the highest burner
zone.  OCS variations are (1) to fire lower sets of burners in             |
a fuel rich mode and upper burners fuel lean and (2) to use
staggered configurations of fuel rich and fuel lean burners with           9
some burners acting only as air ports.  On existing boilers, a             •
load reduction will result if the active fuel burners do not have
the capacity to carry the fuel required for full load.  Most               g
furnaces constructed recently (1970's) are or have been designed
with overfire air ports so that all fuel burners are active even           *
with OCS in operation.                                                     •
Flue gas recirculation (FGR) is accomplished by recycling part
(typically 15 to 30 percent) of the exhaust gases through the              £
burners into the primary combustion zone.  This method is generally        _
restricted to low nitrogen fuels (gas and low-nitrogen fuel oils)          ™
because FGR is most effective for thermal NO.  FGR reduces the flame       •
zone temperature and the concentrations of oxygen needed for NO
production.  Flue gas recirculation requires greater capital invest-       g
ment than LEA and OCS methods because of the need for high temperature     _
fans and ducts and large space requirements for the modifications.         •
However, for those boilers originally designed with FGR (for superheat     •
control), costs of retrofitting are reasonable.
                                                                           I
                            D-8
                                                                           I

-------
I
A
•
               Water or steam injection is used primarily on oil or gas-fired
               systems where thermal NO predominates.  Water or steam injected
               into the combustion zone reduces flame temperatures and prevents
               the formation of thermal NO.  This technique has the greatest
 —
 ™             operating costs of the combustion modification schemes with a
               fuel and efficiency penalty of about 3 to 5 percent.
               Preheat reduction is an NO  reduction technique that has been used
 0             only sparingly because of the energy penalty.  It is applicable only
 _              to  utility steam generators and large industrial boilers which
 *             employ heaters to impart about 500°F incremental heat to combustion
 •             air.  With present boiler designs, reducing air preheat would cause
               significant reductions in thermal efficiency and fuel penalties of
 I             up to 14 percent.  This technique would be feasible if means other
 —             than air preheat were developed to recover heat from 300 to 800°F gases.
 *             Firebox enlargement is a design change usually feasible only for new
 •             boilers because of economic  penalties.  At  any  given  heat input, increasing
               the cooling rate in the furnace  tends  to  lower  peak  temperatures and
 J|             reduce NO formation.   Firebox enlargement like  derating is most effective
               where high heat release rates are employed.   It is usually not feasible
 •             for slagging furnaces.
 •             Derating will reduce NO formation in almost all types of boilers
               provided the same or lower excess air rates are maintained.   Nonetheless,
 g             this method reduces heat or power output.  It does not adversely affect
 _             'neat rate, in fact, thermal  efficiency is normally improved by derating.
•             Burner designs of a wide variety have been  offered to reduce NO formation.
•             For the most part, they are  designed for  Commercial /Industrial boilers
               and employ LEA,  OCS,  or FGR  principles.   The aim is  to strike a
                                             D-9

-------
.
balance between minimum NO formation and acceptable  combustion                .
of carbon and hydrocarbons in the fuel.
     The Japanese appear to lead the way with several  commercial  low-         ft
NOW burner designs in operation and under development.   Considerable
                                                                             I
development work is underway in the U.  S. by several companies,  some         p
under EPA contracts-   To date, new optimized design  burners appear to
have the capability of reducing NO  concentrations 40 to 65 percent from
                                  A
conventional burner designs on gas and oil fuels.   No data were  avail-       ft
able for coal burners but preliminary studies indicate a substantial
reduction will be achieved by new coal  burner designs.   The new burners      ft
are designed to attain good controlled mixing of fuel and air in a           —
pattern that keeps the flame temperature down and dissipates the heat        *
quickly.  Burners can be designed to control flame patterns thus             ft
minimizing peak temperature reaction time between nitrogen and oxygen.
Other designs internally recirculate part of the combustion gases or have    ft
fuel rich and fuel lean sections within a burner to reduce flame             «
temperatures and oxygen availability.  New burner designs, especially        *
for large utility type boilers,  have  not  been completely proven.   Addi-       I
tionally, the effectiveness  of replacement burners for small domestic
heating units has not been fully determined.                                  ft
      Burner design modifications have  the major advantages of not.           »
 requiring redesign of boilers or combustion chambers, not necessitating
 load reduction, and possible applicability to many  types of boilers.         ft
 The disadvantages are that some burners may have to be custom designed
 for specific fuels,  some designs (large burners) are difficult  to           ft
 manufacture, and some may only be applicable to a limited number of         m
 boilers.  However, improved burner design may well  replace the  external
 combustion modifications now in use and achieve significantly lower NOX     ft
 emissions.
         --   -               D-10

-------
 I
 m              For the most part, burner designs are considered applicable to
            CRI boilers.  Nonetheless, Babcock and Wilcox, one of the principal
 I         U.  S.  vendors of utility boilers, has indicated its intent to use a
            dual register burner as the prime means of achieving NSPS
 •         requirements for NO  in new boilers.—'
I                 Table D-5 summarizes NCL  reductions  that can be achieved with
            utility boilers.   The combination of low excess air and off-stoichiometric
 I          firing is seen to provide over 50 percent reductions in many instances.
            Nonetheless, the  degree of reduction is affected strongly by
 |          the base line NO   level before combustion modifications were performed.
                            /\
 •          For those cases where levels were initially low, reductions of only 20
            to 30 percent were accomplished.
 I               The summary  in Table D-6  lists  several  pertinent aspects of combustion
            modification techniques applied to utility-size boilers.
 I

 I

 I

 I

 I

 I
                                                                   *
I

I


-------
                                                                                 I
Costs of Combustion Modifications
     Cost data have been developed principally for utility boilers with          p
emphasis on coal firing.  The least expensive technique, low excess air,         g
represents a capital cost of less than $1.00 per installed kilowatt and has      ~
no energy penalty.  Cost of LEA are presented in Table  D-7 for gas, oil, and     •
            II                                                                   ~
coal firing.-/
     Costs of more extensive combustion modifications are presented in           |
Figures D-7 and D-8.  This information was developed  in  a  1973  study by           _
Combustion Engineering Company and relates principally to tangentially           ™
fired boilers.-'  However, it is believed reasonable to apply the cost           •
figures to wall-fired boilers as well.
                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                                                                 I

                                D-12                                               I

-------
                              FLUE GAS TREATMENT  (NOX)
            Flue  gas  treatment (FGT)  processes  reduce NOX emissions  from  combustion
•     sources either by  decomposing  it  to  nitrogen  and water  or  oxygen or by
       removing it  from the  gas  stream.   Work on  these systems in the  United  States
•     is being funded by EPA  but the major work  is  being conducted  in Japan  both
•     for wet and  dry FGT methods.   FGT is not considered a reasonable control  tech-
       nology at  this  time.  FGT is more advanced for clean  gas streams (gas-fired
I     boilers) than  dirty gas streams (oil or coal-fired),  but the decreased  use of
       natural gas  for firing  utility type boilers will  reduce its potential applica-
I     bility.  For "dirty gas streams", (S02 and particulate), FGT are still  in the
«     developmental  stage.
            Dry systems  are operated at about 700°F and generally employ flue gas
•     additives  and catalysts.  Wet systems employ a wider variety of chemicals
       and are operated  at 100 to 120°F, the same temperatures as scrubbers use
|     to remove  SOp-
m     Dry Flue Gas Treatment
            Dry processes are more developed than wet systems, particularly for "clean"
•     flue qas streams,  that is, gases  from the  burning  of natural  qas or LPG.   Large
       clean gas  streams  in Japan have  been in operation  for over a year.  However,
V     dirty gas  streams  have been piloted successfully and several  prototype
£     plants are now being constructed to treat gases  from oil and coal-fired
™     boilers.
fl          The dry systems which have  been developed in  Japan are catalytic reduction
       (selective and non-selective), catalytic decomposition, electron, beam radiation,
I     and  absorption. Selective catalytic reduction has been the most widely used
•m     process, however,  selective non-catalytic  reduction  of NOX with ammonia has
       been  demonstrated  commercially in Japan  reducing NO   emissions  by 70 percent.^/
                                                          A
•          The selective catalytic  reduction  (SCR)  process normally uses ammonia and
       a  metal  catalyst to reduce NOX selectively to nitrogen  and oxygen.  It is

                                      D-13

-------
termed "selective" because it affects  only NOX.   SCR can  reduce  NOX             «
concentrations in a clean gas stream by more than 90 percent.   Particulates      •
cmd S02 tend to poison the catalysts.   Compared to the wet process, the dry     •
process is simple, requires less space, presents no troublesome by-products,
and requires no reheating of tail gases.  However, the dry process has yet      •
to prove itself on a dirty gas stream of commercial scale.  If the dirty        •
gas is scrubbed to remove S02 before FGT, it will have to be reheated from
about 100°F to 700°F.  Excess ammonia may combine with S0,/S02 and cause        •
a visible plume.  Ammonium bisulfate is also corrosive to mild steel.
Large amounts of ammonia may be required which means an increased consumption   •
of natural ga« {to produce ammonia).-  ti-ke -wet processes, "ammonia requirements  m
are proportional to the quantity of NO  removed.  Thus, combustion modifications
                                      A
are likely to be used to reduce NOX levels as much as possible before treatment I
in FGT systems.
     Table 0-8 shows the selective catalyst reduction processes on commercial    |
and pilot plants in operation or in the construction stage in Japan.  Two        f
large plants, being constructed by Sumitomo Chemical and  Hitachi Shipbuilding
will treat "dirty gas" streams.                                                  I
     A pilot plant on "dirty gas" (oil fired) has been operated by Sumitomo
for over 4,000 hours reportedly without serious problems.  Electrostatic         V
precipitators are used to remove dust and prevent contamination of the           m
catalyst.  More than 85 percent NO  removal has been reported for this
pilot unit.
     Alkaline scrubbing, molecular sieve absorption, and  catalytic reduction
processes have been identified as possible NO  control techniques.    Most        I
of these hold promise primarily for specialized applications where NO           m
                                                                      *           I
concentrations are high or where local considerations require stringent
cont ol.                                                '                         •
     A selective noble metal catalyst  process using ammonia was explored
on a pilot scale through an,EPA contractor.  The pilot plant using natural        •

-------
 I

 I

 I
          gas accumulated about 2,000 hours of testing and achieved NO  reductions
                                                                      A
          of 90 percent with essentially no catalyst degradation.   Further tests  have



          been conducted using fuel  oil  and/or sulfur-containing  flue gases.   These



          tests indicate that platinum is not satisfactory for flue gases  containing



•        SO-.  A final report is in preparation.



               Another study for EPA has been conducted for the technical  and economic



•        assessment of various catalytic processes for NOV control.—   Lab scale
                                                          X


m        tests on simulated flue gas (no fly ash)  investigated several  operating vari-



          ables and catalysts.  The  major emphasis  was on selective NO -ammonia,  non-
                                                                      A


•        noble catalyst systems.  These parametric studies indicated NO reductions  of



          60 to 95 percent at inlet  concentrations  of 250 to 1,000 ppm.



I        Wet Flue Gas Treatment



g             In Japan,—  the wet  processes generally use an oxidation step and many



          yield by-products, i.e., nitric acid, potassium nitrate, ammonium sulfate,



fl        calcium nitrate, and gypsum, some of which have questionable marketability.



          Some wet processes reduce  NO  to the elements and yield no by-products.


                                      |X

          Currently, the Japanese are investigating flue gas treatment processes  aimed



_        at the elimination of both NO  and SO ;  this may be the major  advantage of
^^1                                     A       A


™        a wet system.  Wet systems are better suited than dry systems  for use on



•        dirty gas.  Major disadvantages of wet systems are (1)  expensive oxidizing



          agents and/or energy inputs are needed in proportion to the quantity of NOX



I        removed, (2) some processes create a wastewater problem, (3) demand for by-



_        products may be limited, and (4) many processes require S02 removal first  to



™        reduce consumption of NO  removal chemicals.
                                  A


•             In 1975, there were 12 different wet processes being developed in  Japan



          at pilot plants and small  commercial plants (100 to 25,000 cubic meters per



•        hour).   The largest systems reportedly are treating 32,000 to  100,000 cubic
I
                                                D-15

-------
meters per hour of flue gas.  No firm data are available as to NO  removal
                                                                 X
efficiencies but the range appears to be from 60 to 90 percent.  Japanese
I
systems are directed at meeting stringent levels which are dictated by
ambient air quality standards.  Table 9 lists plants in Japan using wet             •
process FGT systems.

                               GAS TURBINES

     Gas turbines for stationary application range from 40 to 87,000 horse-         •
power (about 65 Mw) with larger units being designed.  Uncontrolled NO  emis-
sions are a function of turbine size and fuel type.  Increasing the turbine         •
size increases the NOW concentrations primarily due to higher combustion
   .
atures.  Oil-fired turbines have higher NO  concentrations than gas-                •
                                          '                                         I
fired units.  Typical uncontrolled NO  concentrations for No. 2 fuel oil
                                     X
and gas-fired turbines are shown in Figure 9.  Variances between turbines of        •
equal size are attributed to design differences and/or fuel characteristics.
     Most combustion modifications for turbines using gas or distillate oils        V
are based on methods to reduce peak temperatures since the majority of NO           •
                                                                                    I
emissions from these fuels are thermal.  However, some gas turbines are
being designed to fire residual oils where the conversion of fuel nitrogen          •
to NO could be significant.
     NSPS studies being conducted by EPA indicate that water or steam               |
injection results in the least NOV emissions.  Significant reductions in NO         m
                                 X                                         X        ^H
can be achieved using these methods but some turbine efficiency (1-3 per-           *
cent) is lost when using water.  Further, the water used in turbines                tt

                                   D-16                                             •

                                                                                    I

-------
 I
          has to be very clean (less than 5 ppm total solids) requiring water
 I
_



*
          preparation facilities.  Providing water or steam of acceptable



          quality to turbines at remote locations may be a problem.



                NO  reduction is strongly influenced by the water or steam to fuel
                  A
 I       ratio.  Equally important is the injection technique.  With optimum



          injection techniques and a water or steam to fuel ratio of 0.6 to 1.0,



 I       NO  reductions of 50 to 75 percent have been achieved with oil firing
            A


 f       and 60 to 90 percent with gas firing  (Figure D-5).-'  Table 10 shows the



          effectiveness of combustion modifications on gas turbines using the various



 I       techniques.  Cost data for NSPS are being developed and will be available



          in the near future.



 |             The proposed new source performance standard for gas turbines, i.e.,



 M       55 ppm (gas) and 75 ppm (oil) at 15 percent 02, should be achievable by



          adjustments in injection ratios for the  size  turbines discussed in this



 fl       section. —



                There are about 14 dry control techniques or combinations thereof



,|       under development for gas turbines; however, none have been put into field



          operation.  The dry 'teUmlnina are*  primary zone leaning; exhaust gas
•



          recirculation; premixed, prevaporized, and well -stir red combustors; variable



flj        geometry; and external combustors.  Development work on dry control techniques



          is being aggressively pursued by turbine manufacturers because it is felt



|        that they will be more economical and attractive to users.  Development



          data indicate that dry control systems may consistently achieve concentrations
          of 15 to 25 ppm NO  at 15 percent oxygen.  Gas turbines may also be amenable
                            A


fl        to control by FGT systems.  However, for a given heat input, FGT will be more



          costly than for boilers since turbines use appreciably greater ratios of



I        excess air.





•                                            D-17

-------
                 STATIONARY INTERNAL COMBUSTION ENGINES                            •

      Stationary internal  combustion engines  (ICE)  sizes  range  f'^m  a              •
fractional horsepower (lawn mower type)  to large multi-cylinder unics  cr           •
over 1,000 horsepower.   Diesel  engines are included in thij  category.
      NO  emissions from these  sources can range from 100 to 3,000 ppm            •
depending upon engine type, size, design,  fuel, load, fuel  to air
                   127                                                             •
stoichiometry$ etc.—•  In  fact, NOV emissions from ICE probably are                •
                                  x
subject to more variables  than  any other stationary combustion  source.            m
      Control techniques for ICE are many and varied but  only two are  being
applied to production ICE  and these only infrequently.   They are exhaust          •
gas recirculation on gas/gasoline engines and turbo-charging with after-
cooling mainly on large diesel  engines.                                            •
      Other methods being  studied to reduce NO  emissions ere derating., water     •
                                                                                  I
injection, modified fuel injection timing, variable compression ratio, optimum
fuel/air ratio, retarding ignition, catalytic converters, and exhaust treatment.  •
Laboratory studies indicate that 35 to 60 percent reductions of NO  concen-
                                                                  A
                                                                                  I
                                                                                  I
trations may be achieved; however, the effectiveness of many of the methods
has yet to be demonstrated in actual  operation and little is known if these
methods are reasonable for existing sources.   Proposed NSPS for stationary
internal combustion engines will  probably be  stated in grams NO  per horse-       •
               127
power per hour.—
      Preliminary annualized cost estimates on the exhaust gas recirculation
system are approximately $200 per ton of NO  removed —   Cost estimates for
                                           /\
other control techniques were not available for this report.
                                D-18
                                                                                  I
                                                                                  I
                                                                                  I
                                                                                  I
                                                                                  I

-------
                                   INDUSTRIAL PROCESSES
 I
               Compared to other major sources, NO  emissions from these processes
 I       are considered minor.  They often represent highly concentrated emissions
 —       (1,000 to 10,000 ppm NO ) in low volume streams.
 I                              '
          Nitric Acid
 •            A typical uncontrolled nitric acid plant will release NOX in the
          range of 1,000 to 3,000 ppm.  Emissions above 3,000 ppm are considered
 •       uneconomical and can be reduced by simple process improvements.  All the
 _        control technology systems to be discussed could be installed on many
 •       existing pressurized plants with costs the controlling factor as to which
 •        one to use for any particular plant.
               Standards of performance for new nitric acid plants were promulgated
I          in August 1971 allowing 3.0 pounds NO  per ton of acid produced.  The NSPS
                                               X
 _        was based on catalytic decomposition systems as other control schemes were
 •        not developed.  Today, other systems are available.
 g              Catalytic Decomposition.  Catalytic decomposition of NOX to the
 _         elements nitrogen and oxygen is still the most prelevant control method
 ™         used in the United  States.  All catalytic reduction processes use some
 •         type of fuel-reducing agent with natural gas and hydrogen being the most
           common.  Energy generated from the exothermic reaction is usually
 |         recovered  and used  in the acid process.  The catalytic reduction systems
 —         are basically designed for streams containing about 3,000 ppm.  At lower
 •         concentrations, the processes may not be economically attractive because of
 •         lower energy recovery.  Operating costs for 100 and 1,000 TPD plants are
           estimated  respectively to be $0.97 to $0.70 per ton of acid; capital costs
I
I
D-19

-------
are estimated to be $207,^00 and $830,000.   Operating costs are directly
related to the cost of fuel.                                                     •
      Scrubbing.   Caustic scrubbing removes NOX but few commercial               _
  installations  use  this process because of problems in disposing of the          •
  spent nitrate  solutions which can create a serious water  pollution              •
  problem.   Removal  of 90 percent of NOV emissions have been reported
                                      /\
  by this  process.                                                                |
     The Masar process uses  a solution of urea to scrub NO ; the nitrated
                                                                                 I
solution finds use as a nitrogen fertilizer.   Two commercial installations       •
are using the process.  Originally, the plants were reported operating at
one commercial installation, 99 percent plus NO  removal was achieved
                                               J\
                                                                                 I
                                                                                 I
exit levels of about 200 ppm NO .   Further tests conducted by an EPA
                               J\
contractor and an independent test laboratory showed NO  concentrations          I
in the range of 55 to 60 ppm from uncontrolled levels of about 1,800 ppm.
The operating cost of this process is reported to be about 30 cents per ton      |
of acid produced (1974 cost data).  Ability to use the by-product is a major
advantage.
      Molecular Sieves.  Two commercial plants use molecular sieves for          I
 NOX control.  They reportedly work well in acid plants where the tail
 gas is bone dry.  The sieve converts NO to N0£ which is absorbed in the         •
 sieve.  Desorption produces an enriched N02 which is reused to produce          •
 more nitric acid.  The increase  in nitric acid production is reportedly
 about 2 to 3 percent]-/                                                         |
     A vendor has reported that during three-day performance tests on
                                                                                  I
and outlet concentrations ranged from less than one ppm to 7 ppm. Since           m
then, the typical daily average outlet concentration has been less than
50 ppm with instantaneous concentrations ranging from 0 to 104 ppm NO .           fl

                                  D-20                                            I

-------
 I
            A second installation is reporting outlet levels of about 180 ppm NOX>
 |         EPA is funding monthly testing of these installations for two years to
 M         confirm the vendor's guarantee.   At one installation a plant malfunction
      •      damaged the sieve such that it probably will  not meet the guarantee but
 •         may still meet NSPS.—/
                 Operating costs for plants  of 100 and 1,000 TPD are estimated to be
 |         $1.75 and $1.35 per ton, respectively; the capital  costs are about $500,000
 -         and $4,100,000.^
                  Extended Absorption.  The  extended absorption process has a second
 fl          absorption tower to receive tail gases from the first absorber and continue
             the absorption process.  Unconfirmed reports indicate that emissions from
 I          this process will meet NSPS.  For 100 and 1,000 TPD plants, operating  costs
 M          are estimated to be $1.53 and $0.61 per ton, respectively and capital  costs
             about $1,200,000 and $6,100,000.—/
 I
                 At small nitric acid plants, batch processes,  storage facilities,  or
 |         other specialty processes NO  may be controlled by  incineration.   The
            emissions are burned by adding excess fuel;  the NOV acting as an  oxidant
            is reduced to nitrogen.   NO  reductions  of 75 to 90 percent have been
                                       /\
            •estimated but not confirmed in plant operation.   Fuel  requirements  are
                                                          13 14/
            probably the main disadvantage of this system.—!—
I          Other Chemical Processes
_               Other chemical  processes which  are  sources  of NO   include  the  production
I
•          of ammonium nitrate, adipic acid, terephtholic acid, nitrobenzene toluene
•          dissolyanate, commercial and military explosives, fertilizers,  and  other
            nitro-nitrate compounds.
I
I
D-21

-------
     Emissions usually occu.  i,« any of these processes at the step in
which the nitric acid and other compound(s) are mixed or .^acted.                   •
Emissions from ammoniated processes are usually negligible because the
reactivity of ammonia is much higher than nitric acid and because  a                •
slight excess of ammonia is usually required for product formation                 •
(NH.NOo).  In most other processes, it is economically attractive  to
capture all or most of the NO  emissions for reuse because nitric  acid             •
represents one of the prime material costs.
     In these specialty processes, caustic scrubbing or NO  incineration           I
                                                          A
in a reducing atmosphere may be used.  Scrubbing with urea solutions may           «
also be suitable.  Control technology is sometimes difficult because the
operations are intermittent in character.  The specialty processes are             •
relatively small but may cause local problems.  Costs may vary widely.
     NOV emissions from industrial and military explosives (ammonium           .  '  •
       A
nitrate, TNT, nitroglycerin, others) are reported to range from 2.5 to 12          m
pounds NO  per ton of product.  Previous control techniques discussed can
be applied to these processes.                                                   •  •
     NO  can fce released Tram fertilizer processes which use nitric acid
for acidulation with phosphate rock.  Only a few manufacturers produce             •
nitric phosphates making this an infrequent problem.  The reaction of the          H
nitric acid with the carbon or organic material in the phosphate rock
produces the NO  emissions.  The use of calcined rock will prevent the             •
production of NO .  For the acidulation step in fertilizer production
                                                                                   I
scrubbers are used to remove particulates and fluorides; however, the scrubbers    •
are not effective in controlling NOX emissions.  No emissions data are             •
available but brown fumes which appear to be NOo are reported to occur.
One company reported that urea (discussed previously) added to the                 •


                               D-22                                                •

-------
 I
         acidulation mixture reduced fuming and eliminated the brown plume.
 I      Ammonium nitrate fertilizer (ammoniating processes) was discussed
 I
I
                    147
         previously.—
              NO  is evolved from metals pickling, bright-dipping copper,
                A
         absorption, catalytic reduction, and NO  incineration.
                                                A
 I       and the manufacture of tungsten filaments.  Emissions reportedly
         can be reduced through the proper use of chemicals as well as charcoal
 I

 *                        PETROLEUM AND NATURAL GAS PRODUCTION

 B            Oil and gas production, pipeline transportation, gas plant operation,
I         and petroleum refining may be significant sources of NO  emissions.  NO
                                                                A               A
         emissions result from the combustion of fuel in boilers, heaters, CO
 I       boilers, internal combustion engines, and gas turbines.  NO  control
         technology for boilers and heaters, I.C. engines, and turbines has been
 •       discussed previously.

                                 METALLURGICAL PROCESSES
              NO  from steel and metallurgical processes has to date drawn less
                X
 flj       attention from pollution control agencies than other pollutant emissions.
         NO  emissions can be traced primarily to the combustion of fuels.  At steel
           |X
         plants, NO  is generated at the blast furnaces (stove), open hearth furnace;
                   A
 _       coke plants, sinter plants, cupola furnaces, basic oxygen furnaces (EOF),
         and soaking pit furnaces.  The phasing out of open hearth furnaces and the
•       switch to electric steel production will reduce these emissions.  This
         would transfer some NOX generation to the power plant where effective
|       NO  control probably can be achieved.
           x
                                             D-23

-------
     Most of the NO  produced in metallurgical  furnaces is believed to b°
                   A
                                                                                   I

                                                                                   I

due to nitrogen fixation but fuel nitrogen may be important also.  Little
attention has yet been directed to the control of NO  at steel plants but          I
combustion modifications should be an effective technique.

           CEMENT, LIMESTONE, CERAMIC, AND GLASS PRODUCTION                        •
     Cement, limestone, and ceramic kilns and glass manufacturing are
other sources of NO  that could be of significance.  Little information            jj
on NOX control or emissions is available.  The majority of NO  emissions           _
comes from the large quantity of fuels  burned  at  temperatures  (1700°  -              ™
2900° F) usually needed for the operation of  the  processes.   Combustion             •
modifications to reduce peak temperatures would be  expected to reduce  ND
                                                                       A
emissions.  However, since high temperatures  are  required  on some of  the            |
processes switching to gas, modification  of firing  design, low excess air,
incineration, or electric heating may be  effective  techniques.                      •

                                                                                   I
                        OTHER STATIONARY SOURCES
     Other sources of NO  emissions are:   refractory fiber material furnaces,
                        A
perlite production furnaces, baking and drying ovens, spray driers, and             •
welding machines (electric arc and oxyacetylene).  Most of these processes
create high temperatures conductive to the formation of NO.  However,               I
                                                                                    •
                                                                                    I
(7-40 ppm).  Combustion modifications (mainly low excess air) or other
treatment methods mentioned previously may be effective in reducing NOX             •

                                                                                    I
                                  D-24
limited ava.lable data indicate that most of these are low NOY emitters

-------
           emissions.
I
I
                                   SUMMARY OF NO.. CONTROLS
           Boilers and Heaters
 I

 I

 I
 —         1.  Combustion modification techniques:
 •              •   are  available  for new  utility  size boilers  and  to  a  lesser degree
 •                 for  retrofit of existing utility boilers,
                •   are  more  advanced for  gas  and  oil firing than for  coal  firing,
 •              •   provide reductions of  30 to 60 percent  in NOX emissions from
                   utility boilers, and
 •              '   are  more  limited for CRI than  for utility boilers  with  burner
 •                 adjustments and new burner designs offering more promise to
                   CRI  operators  than techniques  which  have been effective with
 g                 utility boilers.
           2.  Burner adjustment  and maintenance  programs  to improve  combustion
 •            at  existing CRI boilers may not reduce NOX  emissions and could
 •            increase them.
           3.  Flue gas •treatment -for HO  t
                                       rt
I                   is not considered a reasonable control  technology for NO .
                                                                          /\
                •   won't be  available for oil and coal-fired boilers in the near
•                 future, and it is uncertain whether the processes can be
•                 perfected for  use in the presence of S02,
                •   probably  will  reduce NOV levels by 80 or 90 percent,
                                         A
•              •   may  be extremely costly where  inlet  NO  levels  are
                   greater than 250 ppm,
                  will  have  direct  (wet  processes) or  indirect  (dry  processes)  energy
                  penalties,

                                            D-25

-------
                                                                                   I
      •  will have to be further investigated to determine their
        compatibility with flue gas desulfurization systems,                       I
      •  may create ozone, ammonium-sulfur compounds, or other
        undesirable compounds in stack gases, and                                  •
      •  may generate liquid wastes containing nitrate or nitrite                   •
        pollutants.
Gas Turbines                                                                       I
4.  Water and steam injection can provide 50 to 75 percent reductions in
    NO  from oil fired turbines and 60 to 90 percent for gas-fired turbines        •
      A
    but only at fuel penalties of 1 to 3 percent.                                  •
5.  Proposed new source performance standards can be achieved without water
    or steam injection.                                                            •
Internal Combustion Engines
6.  Limited study indicates that 30 to 60 percent NO  reductions can be            •
                                                    /\
    realized at internal combustion engines.                                       •
Nitric Acid Plants
7.  Several techniques are available to achieve the new source performance         I
    standard level.
Other Sources                                                                      •
8.  Many of the NOX control schemes used for nitric acid plants are applicable     •
    to other industrial sources, particularly those sources which are operated
    under high pressures.                                                          I
9.  Flue gas treatment systems which are being developed for combustion
    sources should be applicable to almost all NOX sources.                        •

                                                                                   I

                                                                                   I
                                 D-26                                              •

-------
  •                                       Glossary

  m        Clean  Gas  Stream -  Exhaust  gases  containing  only  negligible  fractions
  •        of S02 and participate,  as  from burning  natural gas  or  LPG.
            Combustion Modification  - An  alteration  of the normal burner/firebox
  •        configuration  or operation  employed  for  the  purpose  of  reducing  the
            formation  of nitric oxide.
  •        Cyclone Furnace - A type of wet bottom furnace in which combustion takes
  •         place  in cylindrical  cyclone-separator-like  burners.  Ash  becomes molten
            in the cyclone burners and  flows  to  the  bottom of the boiler where it  is
  •         periodically tapped.
            Derating - Reducing the  heat  input and power or steam output of  a boiler
 I         below  the  level for which it  was  designed.
 M         Dirty  Gas  Stream -  Exhaust  gases  containing  significant SCk  and/or
            particulate, as from an  oil or coal-fired combustion device.
 I         Dry-Bottom Boiler - The  common type  of pulverized coal  furnace employed
            at most new power plants.   Temperatures  in the firebox  are maintained
 I         at a sufficiently low level that melting or  slagging of the  ash  does not
 m         occur.  Bottom ash  is removed from the firebox in the dry  state.
            Excess Air - Any increment  of air greater than the stoichiometric fuel
 •         requirement.  With  gas,  oil,  and  coal-fired  boilers, some  excess air is
            used to assure optimum combustion.
 I         Flue Gas Recirculation - A  combustion modification in which  a portion  of
 HJ          the boiler exhaust  gases are  recirculated to the  burners to  inhibit NO
            formation.  (FGR)
 8          Flue Gas Treatment  -  A process which treats  tail  gases  chemically to remove
            NOX before release  to the atmosphere.  (FGT)
                                           D-27
I

-------
                                                                                  I
Fuel Nitrogen - Nitrogen that is chemically bound in the fuel.                     _
Heat Release Rate - The rate of combustion oer unit volume of firebox,            ~
typically in terms of Btu's per hour per cubic foot.                              I
Low Excess Air - A combustion modification in which NO formation is
inhibited by reducing the excess air to less than normal  ratios.
Off-Stoichiometric Combustion - A combustion modification in which NO
25 x 10  Btu per ton provides a heat input of 250 x 106 Btu per hour.
                                                                                  _
                                                                                  *
formation is inhibited by delaying the introduction of part of the
combustion air, also termed staged combustion.                                    I
Stoichiometric Air - That quantity of air which supplies only enough
oxygen to react with the combustible portion of the fuel.                         |
Two-Stage Combustion - A type of off -Stoichiometric combustion.                   _
Wet-Bottom or Slagging Furnace - A type of furnace often used with                ™
older utility boilers in which the ash becomes molten and is tapped               I
from the bottom of the furnace in the molten state.
Field-Erected Boiler - All components of a boiler are delivered to                I
the site and assembled in the field.  Mainly pertains to utility                  •
and large Industrial toilers.
Packaged Boilers - These are usually CRI boilers that are smaller                 I
and more economically assembled at the plant, shipped to the boiler
site, as one integral unit ready for operation after connection to                I
water, steam, and power.                                                          •
Heat Input - The product of the fuel feed rate and the higher heating
value, e.g., 10 tons per hour of coal  with a higher heating value of              •
                                                                                  I
                                                                                  I
                                 D-28                                              -

-------
•         Heat Output - The quantity of heat contained in the steam and/or hot
•         water generated in the boiler, usually the product of the steam rate
           and the enthalpy of the steam.
I         Boiler Efficiency -       Heat Output  x   100.
m                                   Heat Input
I         The overall figure reflects combustion efficiency, radiation and convection
           losses from the boiler and heat lost in exhaust gases.
|         Gross or Higher Heating Value - The heat generated by complete combustion
•         of a fuel, always referenced to baseline temperature, e.g., 60°F.   Heat
           available at the reference temperature is included in the higher heating
•         value even if it is not practically available, i.e., heat of condensing
           water vapor.
|         Net or Lower Heating Value - The heat that is practically available from
_         a fuel to generate steam or otherwise raise the temperature of the media
*         receiving energy.  The net heating value assumes complete combustion.
•         It differs from the higher heating value in that heat of vaporizing
           water of combustion is considered an recoverable loss.
I

I

I

I

I

I

I
M                                          D-29

-------
     Rank
            Table D-l.   Analyses  of  Typical U. S. Coals an^ ' ignite*
Anthracite     Bituminous     Subbituminous     Lignite

Analysis:
  Moisture, %
  Volatile
   matter, %
  Fixed carbon, %
  Ash, %
  Heating value,
   103 Btu/lb
  Sulfur, %
  Nitrogen, %
   2-5

   5-12
  70-90
   8-20

 12-14.5
   <1
  0.5-1
 2-15

18-40
40-75
 3-25

10-14
0.5-5
 1-2
15-30

30-40
35-45
 3-25

8-10.5
1.5-3
1-1.5
 25-45

 25-30
 20-30
  5-30

5.5-8
0.5-2.5
0.5-1.5
      *Research Triangle Institute, "Effects of Transient Operating Conditions       I
      on Steam-Electric Generator Emissions", EPA-600/2-75-022,  August 1975.
                                  D-30


-------
1
1
1

1
1
••
1

1

1


1

1


1
1
1
1
1
1

Table U-2. Analyses of

Distillate Oil
Grade No. 1 No. 2
Analysis
Gravity, °API 35-42 30-35
Viscosity,
Saybolt sec. - 33-37
Heating value,
0
10"3 Btu/gal 134-138 136-144
Sulfur, % 0.1-0.3 0.2-0.8
Hydrogen, % 12-14 12-14
Carbon, % 86-88 86-88
Nitrogen, % <0.01 <0.01
Ash, % 0.01 0.01


*Research Triangle Institute, "Effects
Conditions on Steam-Electric Generator
2-75-022, August 1975.





n_-?i

Typical Fuel Oil*

Residual Oil
No. 4 No. 5 No. 6

23-25 18-22 12-16

45-125 150-700 900-9000

143-146 145-149 149-152
1-3 1-3 1-5
11-12 10-12 10-12
86-88 86-88 85-88
0.1-0.5 0.1-0.5 0.1-0.5
0.01-0.1 0.01-0.1 0.01-0.3


of Transient Operating
Emissions", EPA-600/







-------




















in

O>

•r-
o
CO

>>
•4-*
•i—
•fH
4->
ID

-o
O>
r—
O
s.
-p
E
O
O
E
^3

O

U_

to
r—
d>
>
0)
_l
E
O
•r*
en
in
•r—
E
iii

X
o
•z.



OO
^
rt i
UJ
_Q
IT^
£











































C/7
T
ID
•CJ
E
to
+->
00
d>
o
E
as
cs
jr*
o
<£

dl
Q.
d>
O
j_
3
O
CO

at
z:
a>
.E
•4->
0
•!->

-a
a>
s-
to
Q.
E
0
O






















•a
S-
to
TD
E
to
4J
00

CD
O
E
10
O
«*-
i-
ai
a.

a>
o
S-
3
O
00
d)
•z.















-a
O)
pH_
r—
O
S-
•M
E
O
O
E
ID





























C\
O
&«
oo
-M
to
E
a.
Q.

4->
E
a>
r—
re
>
•I —
3
CT
UJ











a
_t >
^^
CQ
«3
O

"^^
-Q
r—



CM
0

&9
oo

-M
l
3
4->
CQ
i£>
O

_a






•^
(0|
"aJ
3
U_











0)
l-i
L^
^
1_
O)

- vo
LO co en i^» CM
• • • • •
O O O O i—
11411
^r ^a- co «> »o
i— •*»• i— oo u>
« « * « *
0 0 0 0 TD






i— r—
i — IO tO r— IO
•i- O tO •!- O
O 0 CD O O












tO fO r— r— f—
•r- «f— tO tO fO
•M -M 3 3 S
E E
ai ai -i-> -p -i->
en en E E E
E E O O O
ra  LO cri LO i—
1 1 III
O O CD O O
O O CD O O
^r CM «a- oo LO






LO CM oo CM r~
oo i-^ oo i-^ r>>
• • • • •
i— O i— O r—
1 1 III
I--. OO CM OO ^f
LO CM LO ^J- 1^
• • • • •
o o o o o






l_ r_
to ^- ro i— to
to •*- o *i- o
CD O CJ O O










>> >> >>
r— r— i—
to tn to
-M -a 4-> -o -M -o
CO) E<1> Ed) O) O>
OtO OtO Oi/> E E
MO MO MO O O
•r- Q. T- Q. -i— Q. i — r —
S-CL i-Q. S-Q. O O
oo oo oo >> >,
1C Z 3T O C_>














































^
•a
E
• 3
-U O

O CQ
3 CD
•M 0
CQ O
««
0 CO
O i —

« <1J
^- 3

0) *«
3 >
r—
to en
> E
C7)4->
E tO
•i- a>
4J ^=
IO
0) S-
x: ai
.E
s- en
O -r—
-E _C
en
•r— r—
^: -r-
o
to
«3 i —
en ai
3
i— M-
fO
5*- VD
11-i
^-.* ,
ro O
«1














































•X3
E
3
o
Q.
•^
3
-l->
CO
o
CD
oo
r—
d)

^_
(0
>

en
E
1 t
"1 F
to
d)
JE

S-
d)
^:
en
•1 —
-cr

r^
ta
0
U



en
E
•r~
-)->
IO
dl
J^
S-
dl
.E
en
J=

E
o

-o
d)
en
to
.a

•4->
3
Q.
E

4-^
tO
ai
re
^cl
D-32


-------
1
1



1
1
1
••
1

1
1
•1
1

1
1
1
1
1
1
1
1

Table D-4. Typical Baseline Emission Levels
From Commercial and Residential Heating7-/

Emission Concentration, ppm 3%
NOX as
Unit Fuel N°2 C0 HC
Residential Gas 70 15 3
Residential No. 2 Oil 115 65 13
Commercial Gas 80 20 9
Commercial No. 2 Oil 100 4 3
Commercial No. 4 Oil 390 7 3
Commercial LSR* 260 3 5
Commercial No. 5 Oil 290 16 4
Commercial No. 6 Oil 415 10 5


*Low Sulfur Residual Oil 
-------














***"»1
1^*
v^
o:
UJ
— J
o
CO

^™
1—
»— <
_i
•— i
3
o
I"™

•z.
o
»— 1
1—

co
^^ ST"
i— o
•§ <->
•- a:
l—
»— 1
3=

tsy
2:
o
H-l
H""
C_j
^"j
Q
UJ
CC

X
0
z,
_J
o
t— 1
a.
^-
H-

O
ZC
*^
CO

UJ .
>•
LU
MJJJ

X
o
z





z.
0
1— 1
h-
et
t >
»— *
Lu
i— i
Q
O
21

2T
O
*— i
CO
•^-^
CO
s:
0
,
Uv
•- .
' J^.
 
•r"
5






1






cn
in
i
«^-
OJ






cn
^J*
|
f-^
CM












0
o
UD
1
0
0
CO







j
(O
o
0






«o
• ^
4->
C
(U
cn
c
*o
^—








« •
(U


o
n
•o






1






OJ
^^
1
CO
OJ






CO
OJ
1
in
^~





_^
0
o
in
r—
**~r*

0
o
r*s.
i
O
CO









i/i
tJ
CO






r—
'O
2S

4_>
c
o
L.
Lu
























ID

t
r—
CO




in

i
l£)
OJ






in
oo
i
cn
r—






,^-^
O
in
vo
V_rf*

o
in
in
i
0
in
OJ








pv
•r-
O






,__
(0
2

4_>
C
0

u.







^Q
o
CO


• •
I/I
(0
o










1






CO
in
i
^j-
CO






cn
OJ
i
r—
r~












O
in
00
i
in
OJ
«^»







r_
10
o
o






,_
fO


4^3
c
o
i.
Lu







^Q
O



• •
J
•r—
o



































































>.

ns
4-)
c
o
fSj
•r—
i.
^








^47
CO



• •
^

•—
f**~
03
' -M T3
ecu ai » >>
3: o C?

cn
c
*r~
s_
•j—
(^H

"O
« '
i/1
!*••



V
O
^•s^
•a
c
fO
cn
c:
•r—
s_
•r™
(jj_

o
»^-
-M

E
0
•r—
rc~
U
•r-
O

i/)
1
^u.
V-
o

^
a
cn
to
in
i
0

^j
w>
0

ID
r—
U
c



•
d
o
*r-
•M

23
XI
E
O
irt U
•r~*
rO 0)
XI O
*o
>* 4-J
S. (A
•o

J« O
CO *^~
-M
(S/ *O
«r™ •
C ^«
a_ m
p>_ ^»
* *
*
D-34
                                                   I

-------
    I
    I
   I
   I
   I
   I
  I
  I
  I
  I
  I
  I
 I
 I
 I
 I
 I
I
S-
-

vi in
c
O 4J
i- X
4J CO
re z
u
•t- t.
•— 0
cm-
ex
^C




c
en o
"r— 4J
4J re
VI U
x —
LU CL
a.
eC




VI
c
0


(0

•T—

3]




~~
O CM

VI P">
CU
re
ex: vi
U


re

CO
o.
0

n-
0
cu

Q.
i—
U
c
•T-
!-
O.





cu

Cy

C
jr:

CO




1
oj ^~
> c
O VI Ol
4—* •!—
l«- S- VI
o o cu
CL-O
c
o s_ *-•
vi re c
3 3

"u s. s
C T- OJ
1— 1 14— C





0
1
4-> « c: —
•«- >, vi -r- re vi
>4- 4-> i- — V.
O ••— CO CO i- CO
V. r— i— O14J —
co 4-> o re 3 o
o: 3 ja. — a -o


i s-
O O 1 I
cu o 01 1- cu
> CL-.- 0 —
C It- J3 C
O •" CU M- O
u c en 4J vi -f-
o re o vi 4-1
1*- -r- 4J O O O
o +J vi vi a. 3
O "O
Ol CU >,•-•- OJ
C VI S. C C S-
••- re o o
r— CU & ••- -r- -a
3 > •»- 4-> 4J re
o -i- s- •«- re o
U. 4-> Q. C E i—


1.1. &
a. o. o.

O in o
in CM o
» — CM CO
i i i
o in o
O CM O
.— — CM

-» . . i-~
vi i — re
re -t- o
o o o


"O 1 1 1
CU CU 'f- VI
4-> !_ 1- CU
re o.t~-o
i- Ol CL C
cu c c CL re
CL-t- ••- 3
O "O VI f—
.— r- re
VI CO 0) "a E
OJ •»- > c E x
i— >, cu re cu o
N J= OJ 4->
O U CM C —
C ^- O O «*- CU
1- N O 3
s- -a t-
OJ — (U >, C
yt cu o s- o -o
o 3 3 re •!- c:
_i <*- -o E vi re



1 1 Ol
in c c
3 re ^*
J3 4J $-

o *~ ^—
u 4-J

"O X re
CO ~-
cn c 4-1
re o c:
4-J T- CU
LO 4J Ol

t. c
OJ -.-
> c
o vi en
4-> -r-
14- 4. VI
O O CU
CLXI
C
O S- 4->
vi re c
3 3
r— CU
O S- f
C •<- OJ
•-! It- C




14-
0
4-> « C •—
•»- >, vi -r- re vi
1*- 4-> S_ -t- l-
O 'r- CU QJ l_ OJ
oj 4-> o re 3 o
O£ 3 o f^ ^J jQ


1
r— 0)
3 >
O i- S-
JC <*- 4-> 0)
4-1 U »—
*r- * Q] *r—
3E 01 > O
c c .0
C -r- O
O !- U •

VI it- H- O
2-°-^
S. «T3 Dl U
O O C O)
O (J •*- trt


Hi. I.
CL CL O.

O O 0
O LO in
 n «a-
1 1 1
o o o
o in in
CM CM rO

*. •• ,-v
vi i — re

r«t gr^ o


VI
O14-> 1
C S_ C !-
•r- O 1- CO OJ
S- CL C. JC
•.- — O 4J X
*4- J- CU Nl O
— > VI Z
^ re 0) oj cj
cu •— e vi i—
c oj re vi o)
(- Nl CMi — OJ 3
3 -i- O "*- S- 14-
J3 vi a.
V- VI >, CLXI
•0 OJ CU S- 3 C
oj > u re vi re
VI O 3 E
re T3 •!- -O •—
•f- u oj i- c re
CO O I- CL re E



1 •—
VI •—
3 re


O JC
O 4->


OJ C
Ol C ••-
re o s-
4-1 T- •^'
CO 4-> <«~

C i—
01 re
VI t-

-O VI
3
1= T3
1- C
c
o cu
•r- Ol VI
VI t. S_
3 re oj

O *^"
c i»- o





<4- Vlf—
O -r- •!-
•a o
•^ "O CU >, VI

o re re ••- oj
cu re i- 4-> o
OH OI4-I 3 J3





> i
4-> re c
U QJ ••-
OJ -C
14— OJ
•4- " E
cu — re >,
re r- 4J
-a o<*- ^~
OJ o «~
O •"•!-
3 JC VI J3
T3 4-J i — re
OJ •*- f- 4J
oe s o vi

— 'en ^- 'oi
E re D. -r- a. re o. •<-
CL^- CL 1. Q.'-- Q- S-
CL4-> f 4J -f-
IZ C3 «4- O C O >4-
o cu in CM cu in
CM oin r-^ CM cnro ^~
r— C 1 — 1 C 1 r—
i re o re o re o re
§4-> in J in 4-> in x
—'CM ^—r— • 	 CM- — •

. . *.
VI i—
re •»-
o o


i
CU 1
L. CU CL X
E 3 O
vi re vi z
re i —
cn<4- -o • —
c re
oj >, re E
3 C s-
r— re cu cu
>4- E L. JC
^- 3 4->
T3 t. 4->
CU CL re VI
•— S. OJ
O VI OJ VI
>, cu a. vi
O 0 6 OJ
Oj 3 OJ L.
Q£ T3 4J O.





1
(U C
1- 0

t/1 4J

Cn —
3
OJ U
3 S.
U- 0

El c vi
O vi O E
u 3 vi , 01
4-1 •»- VI Ol O
S_ S- L,
C T3 0) OJ CL
o c — c
•^- re i- cu c
-MOO
re r— jo <*- -r-
o re o 4->
— -^.~ re

Q- I- •*- i. 1-
CL cu ^ re cu
<£ E *-> a. c/i




CU OJ
VI >> VI
3 4-> 31
OJ ^- VI T3 3 VI
c -r- u oj-a s-
•^ 4J CU 4J C i — CU
4-> 3 i — •*- •»- re • —
3 -r- E ••- ••-
o c o •— c i- o





VI
1 1 jV VI
O E O OJT3

•o x vi
>>0 -u oj re
JC. <_> « O
•M- S-
-O • V) O O
CU VI C C Ol
C C O V) ••- C
3 ja vi cu •- —
JO U */l > t- 3
c re i-  •»- o
rj o E i— re H-

^^ Ol *^^ Ol ^*^ Ol
E^ C r- C ,- C
Q. «3 -r-  LO (U tf> IT> CU O
CM O1CO r— C\J CHCO r—  7

• • • • r^
VI r— 19
fl8 -F- O
CO O O




x: c
CT*r- (U
3 C
O t^- O
L. O) isi
JT >
•4J ^ (U

r^, (Q
gOJ»—
O M-

C TO >»
o a» w
o u *o

XT3 *»~
O *-

<•- re
CU 4-.
re
CO -a

4^ —
t- JO

re i-

9) >

t|^
C 0
re
J= QJ
«•> Ol
c
vi re
in L.
OJ
•—  •
«4- CL
55 °
O "O" i

itf
•o
C 4J
•r- *v-
JQ O
§ S.
U (O
o
JZ

J C
3
2a>
OT
4-> *O
C L-
O O)
o >
 fl>
3

TO (Q
O) >

3 ^~
r— (Q *
O C "O
X * f- OJ

i— O 1-
fll CT» CO
t. c ex
|Q T— 4)  »— 4-> f—
«3 CL **- fl3
U CX U >
14- ui QJ
••- ^ ai -c

§O 10
T- 1- C

•a (« ex:
OJ 0 O *->
C T- T-


§TO •»— T^
t-> i i§ 'x
~
                                                              D-35

-------
o
u
 I
Q

 a>
41
C 
^ ^_

•- 01
o. >•
IA in
O 4J
i- x
4-> Ol

4J<2,
«
CC in

«• Oi
iSz
C
O

[ *
IO
i.
Ol
0.
o
<*-
o
Ol
Q.

u
c
O-


01
3
cr
c

u
Ol
h-







1










1




4-> 1
C 1-
10 1-
Q. Ol
T3 *—
01 * >>
U E O
3 C C
T3 Ol Ol
Ol JC ••-
ce 4-j o





1



t- i
-- 0
10 •— Ol
s_
o -o +->

4-* V t.
3 '^~ jy
J3 E O
E 01 01 z
O i- 4J
U 3 i-
4-> Ol Ol
•a 10 E i
0) S- 10 0
o a» i— •—
•a £ TJ
01 01 LP c
a: •<-> ai 10
i
Ol
s-
CL

i.
IO


o a>
	 1 JC







1










1



f— W) r— 1
IO E Ol U
E 1 Ol > Ol
E IO r— Ol ••->
Ol «*» 1- f* r— C
-C >, O) O ••-
4-> o a. C -c
c o Q. cn i.
~%3 Ol *^~ Ol
Ol *r- 0> r- JC 4-*
O O i- IO IO
3 -r- Ol C JC S C
•0 «*- > 0 •*-> 0
0) <•- Ol -r- t- t- i-
o; 01 wi 4J » o +•>





1



1
ID
i- 1
01 .—
a. 3

4_>
01
E S
r— (/I (J
<4— u) Ol
o t-
•a Q.I*-
01 01

3 01 e
T3 J- O
Ol 3-r-
ce +J ct


c
o

i- U
01 01

IO C
3 •—
•4J
c
3 >>
2 T-
Ol r^*
C •»- r—
f • IQ
C 3 •»-
.^ t
t t *
COM
O<«- 3

in c c i-
3 cn-f- 01

u 
O cn o U 10
 cn
O -C -r- >,i-
Z 4J ,JE
Ol 4^
f— i.
o 10 o

c oi o x
0 3 J-0
<_) M- 4J Z

1.
Ol
c
S- u?
3 C
.a cn

7 UI
Ol Ol
z^ -a
                                                                       t/1
                                                                       O
                                                                       c:
                                                                       ra
                                                                      -a cr>
                                                                       o r—
                                                                      j=
                                                                      +j s-
                                                                       
                                                                          «>
                                                                       c <-
                                                                       o o

                                                                      •4-> LD
-Q CM

 O O
«-> O
   UD
  X  I
O <
z a.
-(->
 ra
 i-
 O
                                                                           fO
                                                                       O
                                                                       O

                                                                       xl
                                                                       a> oo
                                                                       S-  I
                                                                       3  I
                                                                       O  01
                                                                       «=c  cu
                                                                           u
                                                                        »  s-
                                                                       C  3
                                                                       O  O
                                                                       ••- oo
                                                                       CO
                                                                       Q  c
                                                                           o

                                                                       E +j
                                                                       O)  ra

                                                                       4-> 00


                                                                       CD  O
                                          D-36
I
I
I
I
I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
  I
  I

-------
 I
 I                Table D-7.    Estimated Investment Costs for Retrofitting
 I
Low Excess Air Firing to Existing Utility Boilers   -
 •                    Unit Size                  Investment Costs, $/KVJ
                          MW                   Gas & Oil               Coal
 I                      1,000                    0.12                0.48
 .                        750                    0.16                0.51
 '                        500                    0.21                 0.55
 •                        250                    0.33                0.64
                           120                    0.53                0.73
 I              	

 I

 I

 I

 I

 I

 I

 I

I

I

•                                           D-37

-------
 u
 3
•o
 •>  •  o
                          o
                          o
                          rt
                            t-<           MM
                            
   •H
    03
                         *****
        oooooo0000°ooo
        8888 88888888888828S
                                                                    O
                                                                   -P  (Tl
                                                                         .CBrt
                                                                          O-Hil
                                                                         -H  jd 0
                                                                          rt  03 to
                           'S     -2-d-v-
                            °     n) X  O
 n X  O  -H -H     a     o -H  td
03 CT >i  2 «    K n  JA t2 W
   H

   4»
    C
                          o
                       •  cj
                      •B  a
                      a> Jc
                      X -M
                      O  Q)
                      -HO-HQ;
                                                       0)
                                                          0
                                                       0  0
                                  nJ-HTdO^"
                                  w a  C  »-3 nJ
                    O         •
                   •H  O  O M
                    S-t --H  -H  .
                    O)  O  O -H r-H
                   rH  0)  O X:  Q)
                   W r-t r-( W  0)
                                                                   co ,a x>  co  o
                  O
                                           W

                                           3
                                            10
                                                          CO

        o
        o
        n
        o
                                                     O 4-»
                                                     rt rt
                                                     -u o
                                                     55
                                                     o
                         =  =  =  =  s=swr  =
                                               a
                                            ^  rt
                                           A:  M
                                            O  3
                    Q)  I     -H rH
                   r-t M  X  -C  CI
                   •••> W  M  M  O
                      M  >;  -H -•->
                       I   I  f> C/2
                       333
                      ^1  ^5  U  O
                       3  3  -M >3
                      X  ^  -H  O
                                         w
asterisk
                                         0
                                         cn
                                         o
                                                                                        w
 o
<—I
o
                          D-38


-------
 I
 I
I
 I
 I
I,














oj
cn
c
n
_n
_Q
3
S.
O
oo

+->
(1)
3
co
c
To
ro
E:

ro
St.



cn
I

cu
^
(O
1 —













'o
•u
o
p
r
CJ
n)
*•»*

p (-.;''= =
O C/)
"d rt '
?5 t"
C
O
^
\ °
\ <2
g
o
o
CD
£
r_
O
cu
o
£3
0
W
"^•^

N**\ ^J" ^J"
r- r— c—
o o o
 ft>
f~*\ /^^ |*^


^-^
nJ  *H
•H »ci
a ca
P O
CO E-<

CD
CO
CU
o
0

p
%
^H
o
cu
p
^








o
13 r =
«



a
p
o
»H
CU
cu
t

CD
CO
c
o
1
.
x™x
rH
nJ
CU
^ "H
y
O CO S £
E3 cd
o 1^2
-M
•H -H
fj -r-j
tO JX|

CM
fi '^™*N
w O
CU <*^
KC^
O o3
<•>


tr\
t—
ON
H





4*
J

=







O
0
0
^





•H
CO
rt
1






nJ
T?
Q
r*^
2
O











=












art
*O
O
^*~i
g



O
H



K-\ •<•
C- C-
0 +>
Q> o
(H O



~x
D
M
o s
rH
•H
o
p")




o o
0 O
o o
CM O
o
_j
r*i



il -
C A!
H o

O
•H
^
O
CU
rH
W S

O

o






*^*t
c
C 0
O -H
•H 4J
t3 o
Tl^ s
O a}



<-x
•
O M
•H •
^ W
O -H
a> x:
rM Cl Z
W -H

O P
>> a
O -H
t» S


x^^^
K% Tt
0 0
S cn
H CO C-J
nl Jri



-^- *ir\
t— r-
0 M
V Pi




a "





05 *»H
•H *H
Q -C
O cn
•H
"aJ

cu
0
•H CU
ca ' o
^
•Q rt
P i^<
ca cu
£ i
2 M





X" "X
c
o c c
•HO O
•!-> -/H -H
p< -t-> -fj
H Cd O
O t> P
CQ -H -d
^1 « CU
•< o «



^^^ ^^^^ ,
rH • O
flj S -H rH
+* CU ,H d
CU X -M 0
S O 0 -H
CU * 0
•H C rH TC) O
X 0 W C .C
CQ .C MO
•H -H «tn
f^ 55 O ^* fii
P 0) ^'
to - . > cu
•«-» X -d o H
^ S « * 3
X. X, P^ NS

"\VJ
^ — ^
f j r->
" P
p, '-''
*5 O


ir\
t-
o
ft)
JH


<*
o
M
OJ
iH
•H
o
PM




o
o
o
lf^





d
1
cu










o
g
W






X"^s
§^0
c
•H -H
CO ,O
co ,0
a} o
S CO



O
•H

^j •
0 VH
CJ • •
rH 'd W
W C
M -H

O M tu
a> w

•a o u


/•^ — '
u
13
P;
o'


KN
r—
o
cu
"


— »
W
0)
o
p
u
j3
HH




0
8
r4"





S
6
O





rH
0)


CO

CD
•g
M










0
CU









rH
O
CU

CO

cu


o
H C/l
C\J
C\J M
-I g
f



t*-
r4





"^
^4
CO
rH
*r4
o
PQ




8







•H
cS



.
•4-*
CO

o
ca •
CQ Q
•H CO
0 0







a
o
•H
O
P
CU








•
M
Q
^_J

o
CQ
CQ
•H


















fH
CU
rH
•H
O
J3

tJ
CU
•H
1
rH
O
O

X-Xj
O
M

•H
•H
O

CU
i-l
•H
<«_4
1
ca
nJ
O
^




^
cu
rH
•H
O
-d
M
•H
1
rH
"•S
O
^




1








-------


EFFECTIVENESS OF
*


Combustion
Modification
Interim

Primary Zone
Leaning
Exhaust Gas
Recirculation

Water/Steam
Injection



Advanced Combustors
Premi xed ,
prevapon'^ed,
well stirred,
variable geometry,
external combustors

Table D-10.
COMBUSTION MODIFICATION ON GAS lu^BINES---1--7


Emissions


NOX CO HC Smoke"

10 - 30% Small Small Reduction
reduction reduction reduction
•v30% Negligible Negligible Negligible
reduction effect effect effect

50 - 75% Some Small Small
reduction reduction rpduction inrroaco
(oil) or in- or small possible
60 - 90% crease increase
reduction
(gas)

70 ppm 40 ppm 5 ppm Invisible
achievabl-e achievable achievable



*Prototype unit; catalytic combustor may be able to achieve 5.0 ppm NO .
/\





*


D-40

1

1
I
4M


1
1
|

*
I

1
• ."
|
1





1
1
1
1

1

-------
I
I
I
      Figure D-l.

Tangentially  Fired Boiler
                                         rr-—ir~T •—J-T—-rf— *-.—T~ —»—' .   -
                                         '•   ::    . . • •	'   "	     ,,  "   •
                                             •• - -hi——TT T~l	n	»	
                                        DRAWING  FURNISHED THROUGH THE COURTESY OF
                                       	COMBUSTION ENGINLI:KING. INC.	


                                                    D-41

-------
    WtMOWX
KCONOAMY AIM
DAwrlKS
SICONOAMV AIM-
DAMFER DMIVC
UNIT


              Kf
rj)^
                              w
                                      Nomcs
                                      S>Ot IGNITOM
                                      MOBILE

                                      SJCONOABT Am
                                      COAI Nomcs
              a-
                                      OH GUN
      Tangential firing system incorporating overfire air for
      NO, control — coo/ firmg
                                  Figure la.
                                                        Tangential flame pattern viewed from top of furnace

                                                                                         I
                                                                                      It.

                                                                                      tl
                                                                                      r|
                                                 D-42
                                                                                         1

-------
I
I
I
i!
i
i
i
i
i
i
                        Figure D-2.

                   Front Wall Fired  Boiler
                                                                 EL. l724'-f.'
EL. ITOS'-S"
            \...
            60'tO        SPRM CONTR'.  HCAOUi
          T -      v


---" --•--.. ~" -* .',,' ,  C-'jril-M.rATER OUHET
             ^ ^v^~^f*:^^--/-f'i yy ~i """"1 !
                  "~i ^-i-^r?.:;-^4;.;!j./\~:-4;-ry7.e:-Jii|
                                                                 TEB
                    f.|PqNOAKT SUPtllllf ATER
                    ,  f^QWlQIOM V'Ml^j. '     * '•••'      I'..-1-
                                      \ ?/.,..,;-*>
                                                          •*  EL.IbSl'-IO'
                                               -l1// rUB*A£E'' DEPTH  ;

                             i
                             |	I] EL Ii87;0'
        	   PUljV tRIZIjRS  |   |1
                    i    PMD-1584-8
                                DRAWING FURNISHED THROUGH THE  COURTESY OF

                                        THE  FOSTER WHEELER CORPORATION
                                                 '-   °~43    ;  '

-------
               Figure D-3.
      Front Wall Fired  Boiler
                                                             m'-o"
DRAWING FURNISHED THROUGH THE COURTESY OF
     THE BABCOCK AND WILCOX COMl'Ai.T
                  D-44
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

-------
I
I
I
I
I
I
I
I
I
I
I
1
I
I
I
I
I
I
                        F-igure D-4.


                 Horizontally Opposed Fired Boiler
                =f
                        db=
                         r   '     1      ' f
                      '=?,. |UX-3"|jrlT| K ArTEM^A1!
                      '•  ill ...,,^-lJ..., , llt	1 s.1{  .1 ..__._JJ
                   II
                  "/PfRATOR
                  T
2ZJ'-O"
	-m—^.rji—Jii-:, .\!  | ; jj	 '

=  "1WIST     f"1
| -  . -. - *--=-_ SpiXeyf, FH^rrfJ "~--s---- i's <
!^	;	^	5i^^-_f^^	lr__A_b«pJ.  1_i-"'7t'Tvi
	-; -; jH*' 4-^.^^r^HrrxV%f*~~^'~»'{fH'

piiiilifflifii
•••.'•,\: W-.. »4 s: i-J:.^FRHLArtH.j '.,., ;••:< , f.
                     ^.^miSfi-KH ,!•-.
                     >'•/•,'•,: vsj".i H B:)Ka5'ipF»ML,utH^
                     ;,.:  ,<.!•• .'-.»'-'' HI LiJ w-x} i r' A 1
                     -•• •;;, -;."-v.-H'iLp/RMr^TrR (^  |- ,\-'
               lini^^'^^ir'^n
             m-f i'T?.fl^-:-v>,--;ft
             wr-t' •.-•--.•'-'  : '  • '••''' fl
             ^'-bf^TTTTr^'LU
                        •-"!-.•  A ^ iiri1     x' / ;• = --
                       ..i4:^4J::!! _.__.v.J"-
                  DRAWING FURNISHED THROUGH THE COURTESY OF
                      THE BABCOCK AND WILCOX COMPANY


                           D-45

-------
|:
1:
                   TANGENTIAL SECONDARY
                                    AIR
               PRIMARY AIR
              COAL
                                                        PRIMARY FURNACE
                                                                      -HOT GASES
                                                                 CYCLONE SLAG-
                                                                 TAP HOLE
^
                                                                    PRIMARY FURNACE
                                                                    SLAG-TAP HOLE
           Figure D-5.   Srlicmat i<- draw in}; (if cyclone  furn.'H'C'.   Usually si-vora
                         ryclones are used on a  sinj;!1-"  primary  furnace.
                                         D-46
I
I
I
I
I
 I
 I
 I
 I
 I
  I
  I
  I
  I
  I
  I
  I
  I


-------
I
I
I
I
I
I
        I
       •V
       1 '(
      • f •
      . < •
      '•{••'_
       i • '•
       f"  .
       k;,,
      '}••''
       t.
       (".'
       I''-
I

I

I

I
                                                     Figure  D-6.

                                                  Cyclone Fired  Boiler
                                            £3~f- ... —	  }.
                                   SECONDASV SUPERHEATER  , , , •

                                       OUIUT HEADER
                                                                                    - ECONOMIZER


                                                                                     ECONOMIZER

                                                                                  i   INIET HEADER
 ECONOMIZER

OUTLET HEADER
                                            DRAWING  FURNISHED  THROUGH THE COURTESY
                                                OF THE BABCOCK i WILCOX  COMPANY
                                                               D-47

-------
   <*
106Btu
	
10'Btu
    $
   KM
_ KW
                           200
                        300
400
500
600
700
                                                                          Windbox Gas
                                                                          Recirculation
                                                                          Overfire A1r
                                Combined Overfire
                                Air and Wind-
                                 ox Gas Re-
                                circulation
                                 as Recircula-
                                tion thru Mills

                                Windbox Water
                                Injection
800
      Figure  D-7.
                                  UNIT SIZE
                                     (MW)
           I

           1973 installed equipment costs of NOx control methods for new
           tangentially, coal-fired units (included  in initial design).*

           *Based on:   5400 hrs/yr at  rated MW and net plant heat rate
            of 10" Btu/KWhr (Reference 4-3).
          *Aerotherm Division, Acurex Corporation, "NOX  Combustion  Control
           Methods and Costs for Stationary Sources—Summary Study", EPA-
           600/2-75-046,  September  1975.
                                          D-48
I
 I
I
I
 i
 j
i
i
 i
 i
 i
 i
 i
 i
 i
 i
  i
  i
  i
  i
  i

-------
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
I
I
106Btu
   11

   10

    9

    8

    7

    6

    5

    4

    3

    2

    1

    0
   13

   12

   11

   10

    9

    8

    7
10'Btu 5

       4

       3

       2

       1

       0
                 6.0
                                                                       Windbox Gas
                                                                       Recirculation
                                                                        Overfire A1r
Combined Overfire
Air and Windbox
Gas Recirculation


Gas Recirculation
Thru Mills
                                                                     Water  Injection
                                                                     Including Fan &
                                                                     Duct Changes
                                                                     Water Injection Without
                                                                     Fan & Duct Changes
I
                                        Unit  Size
                                           (MW)

  Figure D_g.   1973 installed equipment costs of NOX control methods for existing
                 tangentially, coal-fired units (heating surface changes not included).*

PG&E Portrero #3  *Based  on 5400 hrs/yr at rated MW and net  plant heat rate of 10" Btu/fcwhr
PG4E Pittsburg #7  (Reference 4-2).


      *Aerotherm Division,  Acurex Corporation,  "NOX  Combustion Control
       Methods  and Costs  for Stationary Sources—Summary Study",  EPA-

       600/2=75-046, September 1975.

-------
F
280


240


200


160


120
 X

i    80
                   SJMPIC CYCIL—^
                   NATURAL GAS
                                            J	I	0
720


600


480


3GO


240


120
                                                                o
                                                               •x.
                                                                -a
                                                                -p
                                                                OJ
                                                                o
                                                               ro
          0    10   20   30   40   50   60   70   80

                           BASF. LOAD, HW
     Figure D-9.  Typical Gas Turbine Base Load NOX  Emissions—'
                           D-50
I
I
I
I
I
 I
 I
 I
 I
 I
  I
  I
  I
  I
  I
  I
   I
   I

-------
I
I
I
I
I
I
I
I
I
 I
 I
 I
 I
 I
 I
 i
  I
  I
    fD
    O
     I
    (D
    O
73  (0
n>  =j
CL  ft)
c  «/>
O  in
tn
    ft)
 •n  -j
 o

 3  -S
 r+  co
 -••  c*-
 o  n>
 ^s  -
    n>
    o
    n-
                                        PERCENT NOX  REDUCTION
                              ro
                              o
                                            o
                                                  en
                                                  O
Co
o
rr I
»—^
o
o
o
                                                  D-51

-------
                              References

1.  Shaw, J.  T.,  and A.  T.  Thomas,  NTIS No.  PB 229-102/AS,  "Oxides
    of Nitrogen in Relation to Combustion  of Coal",  7th  International
    Conference on Coal  Science, Prague, Czechoslovakia,  June 1968.
                                                                                    I
                                                                                    I
 2.   Martin, G.  B.,  and  E.  E. Berkau,  "An  Investigation of the Conversion            _
     of  Various  Fuel  Nitrogen Compounds to Nitrogen Oxides in Oil Combustion",       •
     AIChE/Symposium Series, Air Pollution and  Its Controls Volume 68  (1972).        •

 3.   Turner, D.  W.,  R. L. Andrews, and C.  W. Siegmund, "Influence of                 •
     Combustion  Modification and Fuel  Nitrogen  Content on Nitrogen Oxides            •
     Emissions from  Fuel Oil Combustion",  Presented at the 64th Annual
     AIChE  Meeting,  San  Francisco, California,  November 1971.                        •

 4.   Cato,  G. A.,  et al., "Field Testing:  Application of Combustion
     Modifications to Control Pollutant Emissions from Industrial
     Boilers - Phase I", EPA-650-2-74-078a, October 1974.                            1

 5.   Hobelt, W.  W. and B. M. Howell,  "Control of NOX  Formation in
     Tangentially  Coal-Fired Steam Generators", Presented at  Electric            .    •
     Power  Research  Institute NOX Control  Technology  Seminar, San Francisco,         |
     California, February 1976.

 6.   Brackett, C.  E., and J. A. Borsen, "The Dual Register Pulverized  Coal      .  t   £
     Burner - An N0>, Control Device",  Presented at Electric Power Research
     Institute NO  Control  Technology  Seminar,  San Francisco, California,       ••
     February 1976.                                                                  •

 7.   Bowen, Lachapelle,  and Stern, "Overview of EPA's NOX Control Technology
     from Stationary Sources",  Control Systems  Laboratory, U. S. Environmental       •
     Protection  Agency,  Research Triangle  Park, North Carolina, December 4,       '   p
     1974.

 8.   Blakeslee,  C, £., and  A. P. Selker, "Program for Reduction of NOX              •
     from Tangential  Coal-Fired Boilers, Phase  I", EPA-650/2-73-005,
     August 1973.

 9.   Lyon R.  K.  and  J. P. Longwell,  "Selective, Non-Catalytic Reduction  of         .  •
     NOX with Ammonia",  Exxon Research and Engineering, Presented at the
     Electric Power  Research Institute NOX Control Technology Seminar,              •
     San Francisco,  California, February 1976.                                       I

10.   Jumpei,  Ando  and Heiichiro Tokata,  "NOX Abatement Technology in Japan           •
     for Stationary  Sources", Faculty of Science and  Engineering, Chuo              |
     University, Kasuga, Bunkyo-Ku,  Tokyo, Japan, March 1975.

11.   Draft  of Standards  Support and  Environmental  Impact  Statement for              •
     Standards of  Performance—Stationary  Gas Turbines, U. S. Environmental          •
     Protection  Agency,  OAQPS,  MD-13,  Research  Triangle Park, North
     Carolina  27711, March 1975.                                                    •
                                D-52
                                                                                   I

-------
  I
  I
  I
  I
  I
  I
 I
 I

 I
 I
 I
I
 I
 I
 I
1
I
I
12.   Seiffert, Randy D.  and Frank Collins, "Drafts of Standards
     Support Document for an Investigation of the Best Systems of
     Emission Reduction  for Stationary Internal  Combustion Engines",
     U. S. Environmental  Protection Agency, OAQPS, MD-13, Research
     Triangle Park, North Carolina  27711, September 1975.

13.   Battelle Columbus Laboratories, "Molecular Sieve NOX Control
     Process in Nitric Acid Plants", EPA-600/2-76-015, January 1976.

14.   Control Techniques  for Nitrogen Oxides from Stationary Sources,
     NAPCA Publication No.  AP-67, March 1970.

15.   Roessler, W.  U. et  al., "Assessment of the Applicability of
     Automotive Emission Control  Technology for Stationary Engines",
     EPA-650.2-74-051, July 1974.
                               D-53

-------
                                                                                     I


                          Addendum  References                                        I

 1.   Bartok,  W.  et  al.,  "Systems Study of Nitrogen Oxide Control Methods              _
     for Stationary Sources,  Volume  II", Prepared for the National Air                •
     Pollution  Control Administration, NTIS  Report No. PB 192-789,                    ™
     Esso,  1969.

 2.   Zeldovitch,  Y.  B.,  P. Y.  Sadonikov, and D. A. Frank-Kamenetskii,                 •
     "Oxidation of  Nitrogen  in Combustion",  Academy  of Sciences  of
     USSR,  Institute of  Chemical Physics, Moscow-Leningrad,  1947.                     •

 3.   Heap,  M. P., T,  M.  Lowes, R.  Walmsley,  and H. Bartelds,  "Burner
     Design Principles for Minimum NOX Emissions", EPA Coal  Combustion                —
     Seminar, Research Triangle Park, North  Carolina, June  1973.                      •

 4.   Pershing,  D. W., G.  B.  Martin,  and  E.  E.  Berkau, "Influence of
     Design Variables on the Production  of Thermal and Fuel  NO  from                   •
     Residual Oil and Coal Combustion",  Presented at the 66th Annual                  I
     AIChE  Meeting, Philadelphia,  Pennsylvania, November 1973.

 5.   Hall,  R. E., J. H.  Wasser, and  E. E. Berkau, "A Study  of Air                     |
     Pollutant  Emissions from Residential Heating Systems",  EPA-
     650/2-74-003,  January 1974.                                                      -

 6.   Dickerson, R.  A., and A.  S. Okuda,  "Design of an Optimum Distillate              •
     Oil Burner for Control  of Pollutant Emissions", EPA-650/2-74-047,
     June 1974.                                                                      •

 7.   Shoffstall, D, R. and D,  H, Larson, "Aerodynamic Control of Nitrogen
     Oxides and Other Pollutants from Fossil  Fuel  Combustion",  EPA-650/
     2-73-033a, October 1973.
                                                                                     I

 8.  Browa, TL A.~o -ft. 1L 'Basxm, araSH. J. Schreiber,  "Systems Analysis               _
     Requirenffittts for  Nitrogen Oxide Control  of Stationary Sources",                  •
     EPA-650/2-74-091. September  1974.                                                •

 9.  McGowin, C.  R.,  "Stationary  Internal Combustion  Engines in the                  •
     United States",  EPA-R2-73-210, April 1973.        "                             •

10.  Bartok,  W.  et  al., "Systematic Field Study of NOX Emissions Control              •
     Methods  for Utility Boilers",  Esso  Research and  Engineering Company,            |
     Linden,  New Jersey.   Report  GRU.4GNOS.71,  Prepared for the Office of
     Air Programs,  Environmental  Protection Agency, Research Triangle Park,          _
     North Carolina,  December 31, 1971.                                               •
11.  Jain, L. K., E.  L.  Calvin, and R.  L.  Looper, "State of the Art for
     Controlling NOX  Emissions, Part I:   Utility Boil
     Catalytic, Inc., EPA-R2-72-072a, September 1972.
     Controlling NOX Emissions, Part I:   Utility Boilers", Final  Report,             M
12.  Berkau, E. E., and D.  G.  Lachapelle, "Status of EPA's Combustion                •
     Program for Control  of Nitrogen Oxide Emissions from Stationary                 |
     Sources", Presented  at the Southeast APCA Meeting, Raleigh, North
     Carolina, September  19, 1972.                                                    _

                                  D-54                                               *

-------
  I
  I
  I
  I
  I
 I
 I
 I
 1
 I
 I
 I
I
I
I
I
I
13.  Crawford, A.  R. et al.,  "Field Testing:   Application of Combustion
     Modification to Control  of NOX Emissions from Utility Boilers",
     EPA-650/2-74-066, June  1974.

14.  Levy, A.  et al., "A Field Investigation  of Emissions from Fuel
     Oil Combustion for Space Heating", Conducted by Battelle Columbus
     Laboratories for the American Petroleum  Institute, API Publication
     4099, November 1, 1971.

15.  Barrett,  R. E. et al.,  "Field Investigation of Emissions from
     Combustion Equipment for Space Heating", EPA-R2-73-084a, June 1973.

16.  Crits, G. J., "Economic  Factors in Water Treatment", Industrial
     Water Eng., 8(8), 22 (1971).

17.  Tyco Laboratory Final Report, "Development of the Catalytic
     Chamber Process", EPA-R2-72-038, September 1972.

18.  Esso Research Report, "Development of the Aqueous Processes for
     Removing NOX from Flue  Gases", EPA-R2-72-051, September 1972 and
     Addendum, EPA-R2-73-051a, June 1973.
                                 D-55

-------
  •                                    SECTION E
                                    MOTOR VEHICLES
  I
              1.   NO  Emissions
                    A
              the major NO  emission categories of highway vehicles.*  Within each
                          X
•                Automobiles,  light-duty  trucks,  and  heavy-duty  trucks  comprise
I
I
              of these categories different engine types and fuel  variations  result
              in significantly different emission characteristics.   In addition,
              different exhaust emission standards and compliance  dates apply to
 •           different vehicles.  Because of these variations,  highway vehicle
              emissions change with time and must be calculated  for a specific time
 •           oeriod, normally one calendar year.  The major reasons for this time-
 M           dependence are (1) the gradual replacement of vehicles without  emission
              control equipment by vehicles with control equipment, and (2) the gradual
 I           deterioration of vehicles with control equipment as  they accumulate
              age and mileage.  Detailed information is contained  within AP-42 which
 £           will allow the reader to consider these factors in calculating  motor
 _           vehicle emissions.
 —                Other factors that influence overall motor vehicle emissions include
 •           the vehicle mix ratio (LDV, LOT,  HDVG & HDVD) , vehicle age distribution,
              average vehicle speed, ambient temperature and hot vs. cold operation.
 J            After considering  these factors, as well as  expected VMT growth, a
              composite emission factor  can be developed to estimate overall  motor
 ™            vehicle emissions  from the entire mobile emission class.
 •                 Figure E-l presents a national composite motor vehicle (LDV, LOT,
              HDVG and HDVD) emission rate  projected through 1995, based on  the current
              Federal Motor Vehicle Control Program** (FMVCP).   Incorporated  into  this
              *Automobiles = Light Duty Vehicles = LDV
•             Light Duty Trucks = LOT
•             Heavy Duty Trucks = Heavy Duty Vehicles (Gasoline) = HDVG
                                   Heavy Duty Vehicles (Diesel) = HDVD
•           **ESECA (1974)

-------
composite motor vehicle emissions  projection  is  a  3% annual VMT growth               •
rate which is typical  of ma*"- urban  areas.  As  illustrated, a  14%  reduction
in NO  emissions from motor vehicles is  expected on a  nacunal  basis  during          •
     /\                                                                              ^^"
the 1975-1980 time period.   Congress is  reviewing  the  Clean Air Act  and
if changes are made to the  present motor vehicle emission  standards3  associ-         •
ated changes will  be observed in  the NO   emissions projections.                      •
                                      X                                            I
      The development  of  accurate  VMT growth projections to be incor-
 porated  into the  composite  emission rate projections  is paramount.                  I
 Growth factors  over  a 10-year or  longer period  are very significant
 and are  one of  the principal factors influencing  the  overall  effective-             •
 ness  of  motor vehicle control program.  Figure E-2 illustrates various             M
 growth factors  associated with different annual growth rates  (0.5%  to 4.0%
 per year).   As  shown  by  Figure E-2, automotive  VMT growth factors are               •
 extremely sensitive  to the  change in growth rates.  Therefore, it is
 desirable to accurately  determine the expected  areawide VMT growth  for              •
 the area under study  and,  if necessary,  to correct Figure E-l  FMVCP                 •
 projections from  a 3% annual VMT  growth  to the  applicable growth  rate.
 The correction factor can  be developed  by dividing the applicable growth            V
 factor by the 3%  growth  factor.
      Another important factor which influences  the composite  emission               •
 projection is the vehicle  age distribution for  an area.   Similar  to                 •
 VMT growth information,  locally  specific information  on motor vehicle
 age distribution  should  be obtained if  needed.  Figure E-3 illustrates              •
 how vehicle use varies with vehicle age and  presents  (1)  a national
 age distribution  and (2) an age  distribution  for  Detroit.  As ill us-                •
 trated in Figure  E-3, there is a  much higher  percentage of newer  in-use             m
 motor vehicles (less  than  3 years old)  in Detroit than are in use on
 a national  basis.  Because auto  use patterns  are  associated with  the                •
 auto  replacement  rate, the total  effect of an  auto emission standard
                                                                                    I

-------
 I
            is not fully achieved until 5 to 10 years after a standard is
fl          implemented.  In areas such as Detroit, the high motor vehicle
g          replacement rate will tend to result in a more rapid reduction in
            composite NOX emissions than predicted nationally.  However,  in areas
I            with lower replacement rates, NO  reductions may be achieved  later
                                            x
            than predicted nationally.  On a national basis less than 15% of the
|          in-use vehicles are of the current model year and less than 50 percent
_          were manufactured in the last five years.  In addition to the slow auto
™          replacement rate, motor vehicle emissions typically increase  as an
•          automobile gets older (2% per year for pre-1975 vehicles for  first
            10 years) which also tends to reduce the immediate impact of  motor
|          vehicle emission standards.
                 Another important factor influencing overall composite NO  emission
I
•          factors is the motor vehicle mix ratio.  More specifically, this factor
•          represents the ratio of LDV:LDT:HDVG:HDVD .  The  mix ratio  is  important
            because (1) it represents the weighting factors for the different motor
            •vehicle emission categories which have significantly different NO  emis-
                                                                             x
            sion rates and (2) it can vary greatly from area to area.
•               Figure E-4 illustrates the projected composite NO  emission factors
                                                                  /\
•j          for the four major motor vehicle classes based on the FMVCP considering
            standard conditions and considering emission control equipment deteriora-
•          tion.  As illustrated, on a per vehicle basis, the NO  emissions from
            HDVG or HDVD are significantly greater than LDV emissions.  However, as
•          illustrated in Figure E-5, the much greater total VMT for LDV results
I            in LDV's having the major impact on NO  emissions in urban areas.

I

I

-------
                                                                                        I
    2.  Composite Emission Fac ors
         The development of composite emission  factors  is  discussed in                 •

    greater detail in AP-42 but the procedure  is  based  on  weighted                     •
    averaging of emission factors for in-use vehicles for  the year of

    interest.                                                                           •

         Listed below in the basic summation equation which is used to                 •
    develop composite emission factors:
                                      c   m  v   z
                         enpstw ~  _    cipn min vips zipt riptw

                                 i=n-12
    nominally 75°F; for  speed,  19.6 mph; for hot/cold ratio, 20% cold  operation.
                                     E-4
                                                                                         I
Where:     enpstw = Composite emission factor in g/mi (g/km) for calendar year (n), pollutant (p), average
                   speed (s), ambient temperature (t), and percentage cold operation (w)                     B



    c.   = The  FTP  (1975  Federal  Test Procedure) mean emission  factor for the i        I
      v    model year  vehicles during calendar year (n) and for pollutant (p)          "

    m.   = The  fraction of annual  travel by the  i   model year  vehicles during         •
      1     calendar year   (n)
    v.    = The speed correction  factor for the i   model year vehicles  for             m
      p     pollutant (p) and  average  speed (s)                                         p

    z. .   = The temperature  correction factor for the i   model year vehicles           «
      p     for pollutant (p)  and ambient temperature (t)                               •

    r. .   = The hot/cold vehicle  operation correction factor for the i   model
      p     year vehicle for pollutant (p), ambient temperature (t), and               •
                                                                                          I
        percentage cold operation  (w)

     A review of this composite  emission factor (enpstw) summation

equation  indicates the vehicle  emission factor (c.  ) is weighted

by a VMT use factor (m  )  and  corrected for speed (v.  ), ambient                    I
                      in                             ips                              •
temperature (z.  .) and percent hot/cold operation (r. .  ) if nonstandard
              1P C                                    Ip uW                             M|

contitiorfs exist.  Standard  conditions are:  for temperature, 68°F  -  86°F,           •
                                                                                      I

                                                                                      I

-------
I
             The temperature correction factors are available over a range of
•           20°F-80°F; the speed correction factors ere in two parts, the "normal"
             speed correction from 15-45 mph, and the "low speed" corrections for
I           5 and 10 mph; the hot/cold correction factor is usable from 0-100%
             cold operation (it should be pointed out that, for cars after 1975
|           equipped with catalysts, the net/cold correction includes another
_           factor, hot start percentage, to account for the variation in emissions
™           from catalyst equipped vehicles that have had less than 1 hour to cool
•           before being restarted).  All of  the above correction factors are
             discussed in more detail in AP-42,
I                  In general the above correction factors will effect projected NO
                                                                                  X
             emissions to a lesser extent than growth factors.  For example, most

             whereas the difference between a  2% and 3% annual growth rate over a
I
              operational  correction  factors  effect  NO   emissions  by  less  than  20%
                                                     /\
              twenty year period will  make a  30%  difference  in  NO   emission  projections.
                                                                X
•            Because of the different relative importance   of  the  various factors,  they
              should be considered  on  a priority  basis  starting with  the  factor which

                   In relation to the  specific operational correction factor,  Figures
             will effect NO  emission  calculations  the most.
                           X
              E-6,  7,  and 8 present speed  correction  factors  (V.   ).   As  illustrated
•            N0v emissions increase both  as  average  vehicle  speed  is  increased  or
              decreased from standard conditions  (19.6 mph).   The ambient temperature
•            correction (Z.  .)  factor (Figure  E-9)  increases  as  the ambient  tempera-
•            ture  is  reduced from standard conditions (75°F).  The final correction
              factor,  the hot/cold operational  factor (r-  t  )  is  a  function of two
•            variables (see Figure E-10).  The first variable is percent cold
              operations (w).  The NO  correction  factor  reduces  with  increased  cold
                                     |X
              operation.  The second variable is  ambient  temperature which also  causes

I

-------
                                                                               I
the hot/cold correction factor to be reduced at lower temperatures.
In summary, the NO  emission rate for motor vehicles is maximized at           •
                  A
high speeds, low ambient temperature, and steady state conditions an'4          •
minimized at medium speed, high ambient temperatures and short-term
operations.                                                                    I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
                                                                               I
E-6

-------
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
   1.4
   1.2

to
C£

c     *
°  1.0
^  0.8
o
_c
O)
 S-
 o
    0.6
 S-
 o
    0.4
    0.2
    o.o1—
     1970
                                          FIGURE E-1
             NORMALIZED MOTOR VEHICLE EMISSIONS RATE
                                     I
                                     I
     1975

Assumptions:
1980           1985

  CALENDAR YEAR
1990
1995
                1.   National  average automobile and truck age distribution
                2.   Low altitude, standard conditions
                3.   3% Compounded (annual) growth rate
                4.   National  average vehicle mix (LDV 80.4%; LOT 11.8%; HDG 4.6%; HDD 3.2?
                5.   1970 composite emission factor 4.6 g/mi
                                                 E-7

-------
                                         FIGURE  E-2
                                GROWTH FACTORS (GF) vs TTMF (T)
GR = annual  growth rate  (%}

GF = ,      GR
                                                                                       I
 2.2  ..
                                                  GR = 4%
  2.0
  1.8
00
o:
o


§1.6
o
o;
  1.4
  1.2
                                                     GR = 3%
  i.a
                                                     GR = 2%
                                      10          15


                                   YEARS (T)     E-8
                                                   20
                                                                            I

-------
 I
   20
I
I

I
             FIGURE E-3

LDV TRAVEL BY MODEL YEAR (min)*
                 National
                 Average
                 (AP-42)
    *Based on  1972  Data
         468
             Automobile Age  (LDV)
                       E-9

-------
   20
   15
E
\
CO
s
o
c
o

   10
    1970
                                          FIGURE E-4
                                          rACTOR FOR L
                                   VS. CALENDAR YEAR
COMPOSITE NOV EMISSION FACTOR FOR LDV,  LOT,  HDV,  AND HDD
            A
                                    T
                                                   T
                                                              HDVD
               LDV =  Light-Duty Vehicle
               LOT =  Light-Duty Truck
               HDVG = Heavy-Duty Vehicle
               HDVD - Heavy-Duty Vehicle
                        Gasoline
                        Diesel
                                                              HDVG
                                                   I
 1975
 *Low altutude; 49 state
  vehicles, standard conditions
1980           1985
  CALENDAR YEAR
                                                                 1990
1995
                                                                 E-10

-------
    I
    I
    I
   I
   I
   I
   I
  I
  I
  I
  I
  I
 I
 I
 I
I
I
I
    ---.o

    CM
    oo
    co
                                         CM
                                         oo
    *
    o
LO

UJ
UJ  X
ry  i—i
t—i  UJ
U_  _1
    o
                    OO
        O
        CO
                                                      X)
                                            E-n
                                                             fc*
                                                             ID

                                                             CM
« n
"
CM |
                                                           cs«
                                                           •
                                                                    Q
                                                                         c:
                                                                         fO
                                                                        -Q
            3
            OO
             I
                                                                         Q.
           O

            s_
            cu
           +->
            E
            CU
           o
            I
       Q  r—
       —1   (O
            O
                                                                    Q
03
>•   CU
Q  T3

     %
                                                                   h-   4->
                                                                                 c
                                                                                 o
J3

i.
                                                                                 o
                                                                                o
                                                                                 c
                                                                                 o
                                                                                -a
                                                                                 cu
                                                                                03

-------
                                                                                                                                   o
                                                                                                                                   un
o:
o
  CO
  a
a:
o

tl
et
Di
CtL
O
O
UJ
CL_
oo
  X
           c:
           o
 o
 OJ
 S-
 s_
 o
 o

-a
 ai
 0)
 CL
 CO

 to
 O)

13
a>
>

CD
+->
(T3
-M
CO
 I
           OJ
          T3
 CD
                                                                             0)
                                                                             OJ
                                                                             Q_
                                                                            00

                                                                             CD
                                                                             O
                                                                            a:

                                                                             CD
                                                                             a>
                                                                             ro
                                                                             s_
                                                                             CD
    	     o
           CD
          4->
           O
                                                        CX3
                                                         •

                                                        O
(S
-------
          >-

          
-------
*
O)
           C\J
                                    CO
                                     *

                                    O
10
 •

O
(SdtA)
                                  NOIIOB^OD Q33dS
                   E-14

-------
 I
 I
 I
 I
 I
 I
 I
 t
  o
  
-------
 ID
-P     ID
 ra     o
 s_
 QJ  at o
 Q. s- to
 E  3 r—
 0)  -(-> 03
HtJ  ro
    1- 4->
-!->  OJ CO
 C  CL 3
 
     C   T
 Li_  oi  r-J
O  'I— ^-C
 LO  o
 r^»E  s-
     ro  O
 -!D     -M
 C -t-J  O
 c -a
 O  OJ E
•,- -i- o
4-> I - •!-
 (0  CL4->
 :-  o. o
 O
 -c:
         CL
       O
      •
      201
      CC3
S-S
O
03 S- (T3
"*•«. --- i-
-C3    O)
r~ i. Q.
 O O E
 U 4-> O)
    O 4->
5-S ro
C3 M- 4->
OJ    C
    C O)
 aj o -i-
 (/I O  ro
 c/1 OJ
 ro S-   •>
    S- U_
 a; o o
i— O LO
 O    1-^
 O i
    O  ro
4-> O _c
 (/) ^^> 4-> TD
 rl) 4->     OJ
I— O  S- •!-
    J^  O) r—

                                CXI
                                                     o
                                                     o
                                                                          LO
o
LO
                                                                                                                 un
                                     ,MldL
                                           -
                                                              Noii33>dyoo
                                                                                                                           E-16

-------
I
I
                   An NO  emission limitation for light duty vehicles (LDV) (i.e.,
                        X
I
              3.  Motor Vehicle Emission  Standards
•            Light Duty Vehicles

              any motor vehicle with a gross  vehicle weight  (GVW)* of 6,000 Ibs.
•            or less and used principally for transportation  of  people) was  . v.
              established by Section 202  of the Clean  Air  Act  (CAA)  of  1970 as
•            amended.  The Act required  EPA  to establish  regulations that would
              •require 1976 model LDV's to reduce NO  emissions by 90% of their
                                                  X
              uncontrolled 1971 emission  rate.  On July  2, 1971  (at  36  FFM2652)
•            later recodified on  November 15, 1972  (at  37 FR  24250) the Administra-
              tor established the  following emission standards for NO   emissions:
                                                                    |X
                   1973 model year - 3.0  grams per vehicle mile
_                 1974 model year - 3.0  grams per vehicle mile
                   1975 model year - 3.1  grams per vehicle mile
                    1976 model year - 0.40 grams per vehicle mile
                    On  July  31, 1973  (at 38 FR_ 20365) after testimony by automobile
 |            manufacturers, control equipment suppliers and the National Academy
 «            of  Science which had indicated that the statutory standards could not
 *            be  met by the required attainment date with acceptable reliability,
 •            and after the Administrator had determined that full 90% control was
              not generally needed to attain national standards, except in Los
 |            Angeles  (June 8, 1973, F£ at 15183) the Administrator under the
 ^            suspension provision of Section 202(b)(5)(D) granted a one-year
 ™            extension (until 1977) for compliance with the statutory standard to
 •            some automobile manufactuers.  In conjunction with the extension, the
              I*
               Total weight of vehicle and maximum load as rated by the manufacturer.

-------
                                                                             I
Administrator or. July 305 1973,  established  a  national  interim                I
standard of 2.0 grams/mile for 1976 model  motor vehicles  and  postponed
the 0,4 grams/mile standard to 1977 model  vehicles  (August 21,  1973  at        |
F_R 22474),  At that time it was  generally  believed  the 1976 interim           •
standard was the lowest emission level  that  LDV could achieve without
the use of a reduction catalyst.                                             fl
     In June 19749 the Energy Supply and Environmental  Coordination
Act (ESECA) modified and postponed these emission rates by legislative        |
decree,,  Specifically ESECA suspended all  automotive emission standards
                                                                             I
for an additional year; i.e., the NO  statutory standard of 0.4 grams/
                                    A
mile was postponed to 1978.  The 1976 interim standard of 2.0 grams/mile     •
was postponed to 1977 and the 1975 standard of 3.1  grams/mile was main-
tained for 1976 model vehicles.  The present standard (i.e., for 1976        |
models) is thus 3J grams/mile.  These standard and proposed changes
are summarized in Table E-l 1.                                                •
     EPA has recommended to Congress changes in NO  standards for            •
                                                  X                          I
automotive sources.  On March 5, 19759 the Administrator recommended
that the NO  automotive standards be established at 2.0 grams/mile           I
           X                                                                 ^B
for vehicle models 1977-1982.  Final  action on automotive emission
 standards by Congress is anticipated during
     An analysis was conducted by OAQPS which predicted air quality          •
 levels in ten cities resulting from eight different emission standards
 combinations (options).   The ten cities (Phoenix;  Los  Angeles;  San Francisco; I
 Denver; New York City; Philadelphia; Washington,  D.C.; Chicago; Baltimore;
 and Salt Lake City) represented the "worst-case"  situations (considering     •
 air quality and growth)  from a list of about thirty urban areas for          •
which 1972 data were available.  The analysis indicated :hat future N00
                                E-18
                                                                              I

-------























CO

rv
_
I—
ID
Q
1 —
31
CD
^—^
	 1
X
O
~^
LJL-
O
>-
>
0 -Q

fO C
r- 0
CD tO
O) to
'i
.C OJ
(/I
•i- X
i — O
-Q ~Zi
<0
4-> O) S-
l/l >  E r—
O Ol

O) 1*"^ f^*
s_ cn cn
3
cr O) O)
o> o -c:
S— "^ 1 ^
-tu
3. O) S~
(O S- O
,_~. (4 	
-ft \
O) ft3 c^si
x: JE o










-o
O)
"^3
c
01

n3

to
<0
f*
o

cn
i,_
o

^_)
o
e3^

?L-
• f—
C^

C

oo
c
o
to
to

E
LU

X
o




CM
OO
cn
oo
cn
i —

o
00
O-i

cn

cn
r— ™


CO
r^^
cn


^
p*^
cn



**Q
1^.
cn
•"

UD
cn
i —


^j-
r--
cn
•~
oo
en
^~












O)

(O
f"ts
















>^
cn
0)

*o
S-
.{-3
CO





^" 
• • • • •
O O O OO CM


*d- «d- O i— O
• • • • •
O O CM OO CM



«3- O r- r— r~
• • • • •
O CM OO OO OO


t— n— n~ r—~ r~~
CO OO OO OO OO



r— r— r— r"~ r~™
• • • • •
OO OO OO OO OO

,- r- r- r- n-
oo oo oo oo oo







oo un LO
r^. cn cn cn
cn i— ^d- i— i—
r~~ r^»
** cn ** *•
»» o i — r^*. to
CM OO CM
•s c"
>-, >, O) O) O
•— r— C E S_
Z3 3 ^ 3 03










to
to
01
cn
0
o

^"^
_Q

T3
O)
•r-
"O
3
1 \
-*— '
C/l

cn
c
•r—
O)
_o

O)
S-

to
•o
S-
CO
•o
c
fO
•4-J
t/5
c
o
to
•1 —
E
O)
Ol
_>
-p
0
E
-1-5
to

in
3
o
•I —
S-

•f—
(O
.4_>
C
^-x QJ
C in
O O)
•r— tO S-
(/) *^-* Q
C C O)
oj o) cc:
•»-> E
X "O 4-
LU C 0
O) Ol
S- E O) +->
 3 C
>, "O C O O)
i O) o) in co
i — * 
E-19

-------
                      I
levels will exceed the air quality standards in most of the ten    •
cities under all eight of the automotive control options, primarily
because of the growth of stationary sources which will constitute    •
the major contribution of NO emissions. Variations in the control
        I"
each of the ten cities studied by affecting the rate the N02 air    m
quality level deteriorated. Under the strictest option (i.e., 0.4
gram/mile), an average increase in ambient NO concentrations of 6   fl
percent by 1980 would be experienced in the 10 cities examined, and
under the most lenient option (i.e., 3.1 gram/mile), the average    |
increase would be 16 percent by 1980.           ^
Light Duty Trucks (LOT - gasoline powered)
  Uncontrolled NO emissions from gasoline powered LDT's range    I
      X                ^H
between 1.6 to 5.3 grams/mile, depending upon age of the vehicle and
whether the vehicle is operated at low or high altitude. Presently   •
the LOT standard is identical to the LDV standard; i.e., an emission   •
limitation of 3.1 grams/mile beginning with model year 1975.
  An NO emission standard of 2.3 grams/mile beginning in 1978 for  •
light duty trucks was proposed in the Federal Register in February 1976.
The proposal will also change the distinction between light and heavy   V
duty trucks from the present 6,000 Ibs GVW to 8,500 Ibs. GVW. This   •
proposed LOT standard is significantly below the uncontrolled emission
rate of N0x, which was approximately 3.5 grams/mile in 1967 prior to   I
the introduction of HC and CO controls and which caused the average NO
emission rate to increase to 5.3 grams/mile in 1973.       I

          E-20           I
                      I

-------
I

             Heavy Duty Trucks (HOT)
I                  Uncontrolled NO  emissions from gasoline-powered HOT range from 4.1
                                 x
             to 12.6 grams/mile depending upon the age of the vehicle and whether
•           the vehicle is operated at high or low altitude.  Additionally, the NO
                                                                                   /\
•           emission rate from diesel  powered HOT is approximately 21  grams/mile.
             The current standard in effect (see November 15, 1972 FR^ at 24287)  is
•           combined HC and NO  emission limitation of 16 grams/brake horsepower
             hour.  This standard applies to vehicles of model  years 1974 through
I
              1977.    In  addition,  a  combined  standard  for hydrocarbon and NOV of
                                                                            X
              10 grams  per  brake  horsepower  hour  beginning with 1979 model vehicles
             horsepower hour for NO .
                                   X
 ™            was proposed for heavy  duty  trucks  in  the May 24,  1976, Federal Register.
 •            This standard is approximately equal to  a standard of  9 grams per  brake
 I
 I
 I
 I
 I
 I
I
I
•                                           E-21

-------
I
I
I
I
I
I
I

I
I
I
 I
 I
 I
 I
 I
 I
 I
                            SECTION F


                      TRANSPORTATION  CONTROL  PLANS
    : The need to reduce automotive emissions  in  some  areas  below the  levels
resulting from Federal  Motor Vehicle Control  Program  (FMVCP)  was specifically
recognized in the Clean Air Act.   After review of  the SIP's,  EPA required
certain states to submit plans containing various  transportation control
measures to reduce automotive emissions in 27 Air  Quality Control  Regions.
On June 8,'1973, the Administrator promulgated regulations  to amend 40 CFR,
Part 51, to clarify the requirements for transportation control  strategies.

     Transportation control measures included in SIP's are  of two basic types;,
i.e., measures that reduce emissions from individual  vehicles and measures
that reduce general automobile use (vehicle-miles-traveled  or VMT).   The
first type of control measure includes inspection/maintenance and retrofit,
programs.  The second type includes transit improvements, carpool  programs,
disincentives to the use of low-occupancy automobiles and parking restric-
tions.

Impact of_ Various Transportation Control Measures  on_ NOx Emissions

     The principal thrust of transportation measures  to date has been aimed
at reducing levels of carbon monoxide  (CO) and photochemical  oxidants (Ox).
In some cases those actions result in concomitant increases or decreases in
NCx emissions.

     Auto-used and emissions reductions achieved by transportstion controls
derive  from the  effects of the .entire group of measures included in a tran-
sportation control plan, rather than the effects of individual measures.
Moreover, the effectiveness of specific auto-used reduction approaches is
strongly dependent on  local conditions.  Hence, in any consideration of NOx
reductions identified  with specific control measures, it is necessary to
view  these reductions  as rough estimates which are subject to change when
placed  in the operating framework  of the entire TCP for a particular area.

      (a)  Non-VMT measures.

      Several  control measures are  available  to reduce emissions from  in-
dividual  vehicles.   Since  these control measures require that individual
vehicle emissions be reduced  by a  certain  amount, it  is relatively erisy
 (when compared  to VMT  reductions)  to quantify emission reductions that may
result from  the  implementation of  these control measures.
                                     F-l

-------
                                                                              I
Inspection and Maintenance
     Inspection and maintenance  (I/M)  programs, which provide For in-          |
spection at least once a  year  to  primarily check HC and CO emission rates
of motor vehicles, do not significantly affect NOx emissions.  Analyses      '  «
of two studies by Olson Laboratories  showed  that I/M increased annual          I
emissions of NOx by 0.8 and 1.4  percent respectively.  Neither of these
increases was statistically significant,  even though fleet sizes were larger
(600 and 144 vehicles).  These negligible increases in NOx levels are          •
due principally to increased temperatures accompanying improved combus-   '     •
tion efficiency.

Retrofit                                                                       I

     Retrofit means the addition or removal  of an  item of equipment, or  a       «
required adjustment, connection, or disconnection  of an existing  item of  '     I
equipment, on an in-use vehicle for the  purpose  of reducing  emissions.
Retrofit devices can be used singly or in combination with other  retrofits   .
to optimize control of NOx, HC and CO emissions  for both  light duty and         •
heavy duty vehicles.  Studies on both light and  heavy duty vehicles have       •
demonstrated the potential for retrofit  devices  to be very effective in
reducing NOx emissions, all of which are contained in the exhaust gases.       •

     ,NOx,.retrofits can be used on both controlled  (1968-1974) and on pre-      • .
1968 uncontrolled vehicles.  Of the two  approaches currently certified           M
for use  in California, one uses exhaust gas recirculation (EGk)  plus            •
vacuum  spark advance disconnect (VSAD) and the other  uses only VSAD.
The NOx  control devices used for the California  retrofit program for
1966-1970  vehicles were designed to reduce NOx emissions by at least 40         •
percent without increasing HC or CO emissions.                                  *

     The central  technical problem in controlling NOx emissions by retrofit     •
is  to optimize the choice  among various combinations of retrofit devices con-   •
sidering the  pollutant problems at hand.  Another major variable affect-
ing the optimization  of  retrofit devices is altitude.  Studies in Denver,       •
Colorado r  have shown  additional reduction in NOx emissions from retrofit     :   |
at  high altitude  although  simultaneously increasing HC  and CO emissions.
The choice of retrofit options  is  thus a delicate balance among the three       _
pollutants,  the feasible technical approaches, and the estimated use of  the,    I
vehicle.                                          •            '
                                                                    i;
      Additionally, the California  retrofit  problem encountered stiff public     I
opposition.   Therefore,  a light  duty vehicle retrofit program must be viewed     •
as one  of  the lesser politically feasible measures.
                                      ,F-2
I

I

I

I

-------
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
 I
   _ Measures

     VMT reduction measures most frequently found  in  TCP's  approved or
promulgated by EPA include:  transit improvements, carpooling'programs ,
priority 'treatment for buses and carpools on streets  and  freeways  (e.g.,
exclusive bus lanes), and parking restrictions.   These  interrelated
measures reduce VMT, hence reduce the amount of  fuel  burned and  con-
sequently the amount of NOx emissions.
v

     The maximum emission reductions f^om transportation  measures  will
result from coordinated measures designed to discourage low occupancy
auto use and to encourage transit and carpool  use. However, transit and
carpool incentives by themselves are insufficient for achieving  signifi-
cant emission reductions.  Programs that do not  incorporate parking
restrictions, surcharges, or other disincentives are  unlikely  to achieve
emission reductions greater than 5 to'10 percent.   For  further information1
on specific measures refer to the attached list  of reference materials.
                                     F-3

-------
    _
    EPA-460/3-74-021
                                                                              I
                         References/Bibl iography
             £f Control  Strategies for  In -Use Vehicles, EPA , December 1 974 ,    jj
                              *
2-   Applications for Accreditation of  NOx Control Devices, State of California, •
   'Air Resources Board  (undated)

3.   Transportation Controls  to  Reduce  Automobile Use and  Improve Air Quality   •
     n C        PA                    -       --                              •
    in Cities, EPA, November 1974,  EPA-400/1 1-74-002

4.  An Evaluation of Retrofit Devices  for  Heavy  Duty Vehicles,,  (Draft),         •
    New York City Department of Air Resources, December  1975                    •

5.  Effectiveness of Short Emission Inspection Tests in  Reducing  Emissions,     •
    through Maintenance, Olson Laboratories for  EPA, July 1973, EPA-460/3-      •
    73-009                    .                                                 "

6.  Degradation Effects on Motor Vehicle Exhaust Emissions ,  (Draft),  Olson      •
                   r                                                           •
    laboratories for California Air Resources Board,  1976

                                                                               I

                                                                               I

                                                                               I



                                                                                I

                                                                                I
                                                                     r

                                                                                I

                                                                                I

                                                                                 I

                                                                          ,       I

                                                                                 I

-------
                                        SECTION  G
                                   FIELD OBSERVATIONS
I
I
I
_                Recently a study of short-term NO  concentration distributions
I
•           over urban/suburban areas was conducted.  A review of available air
•           quality data indicated that only St. Louis (25 sites) and Los Angeles
             (24 sites) had sufficient data for analyzing the spatial character of
I           NOp.  Three days of hourly data were analyzed for each city with days
             of relatively high NOX concentrations selected for analysis.
•                A review of the 24-hour NOp concentrations in St. Louis indicated
             that the highest NQ0 concentrations were recorded in an area along the
              prevailing wind direction  and  slightly  downwind p_f_ the major industries
•            clustered near the  center  of the  city.  On each day, the concentrations
              would rapidly  decrease with  increasing  downwind distance Such that sub-
•            urban NOp concentrations at  25 miles  downwind were only one-fourth to
m            one-half of the city  center  value.   (See  Figures G-l, G-2, and G-3.,)
                   In  Los Angeles the 24-hour NOp  concentrations patterns were more
•            complex  than in St. Louis.   It is expected that the  day/night land/sea
              airflow  patterns and  complicating topographical features in the Los
|            Angeles  Basin  tend  to channel  and inhibit surface air flow and result
•            in  complex wind flow  patterns.  For  the days analyzed similar concentra-
              tion  patterns  were  observed.   On  each day there appeared to be four
B            different areas of  high N02  concentrations with all  four maxima located
              downwind of the Los Angeles  city  center.  The 24-hour N0? concentrations
              in  the basin dropped  rapidly with increasing downwind distance with an

I

I

-------
                                                                             I
approximate gradient of 20 wg/m  (0.01  ppm)  per mile.   The  analysis
also indicated that N0£ concentrations  in Los  Angeles  may  be  twice  as
high in the fall and winter as in the spring and  summer.                      ™
     A review of the 1-hour NOp data for St. Louis  indicated  that peak        •
1-hour N02 concentrations also occurred downwind  of major  city  sources
from 8:00 p.m. to 10:00 p.m. on 2 days  and 4:00 a.m. to 8:00  a.m. at         I
the center city sites on the third day.  (See  Figure G-4.)  The general
urban area (excluding the center city)  reached its  maximum concentration      •
at 10:00 p.m. on the third day.  In Los Angeles maximum 1-hour  concen-        •
trations occurred during the mid-morning to noontime along the  coast and
center city, but during the evening in  suburban and inland sites.             I
     In summary, the analysis indicated that high short-term  N02 concen-
trations tend to occur in and immediately downwind  of  the  city  center        |
and decrease rapidly with distance outward toward rural areas.   These        _
findings imply that the maximum annual  NOg concentrations  in  an urban        *
area would be expected to occur slightly downwind of the center city         I
industrial complex along the most persistent wind directions.
                                                                             I

                                                                             I

                                                                             I

                                                                             I

                                                                             I
                                                                             I

                                                                              I


-------

-------
G-4

-------
6-5

-------
         P)
         o

o\
o.


                              G-6
                                                                                           Oil

-------