EPA-453/R-92-G17
      Alternative Control

   Technology Document

                for

   Bakery Oven Emissions

        Emission Standards Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
        Office of Air and Radiation
   Office of Air Quality Planning and Standards
  Research Triangle Park, North Carolina 27711
            December 1992

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             ALTERNATIVE CONTROL TECHNOLOGY DOCUMENTS
                                                   sr °omwroial
Information Service,  5285 Port  Roval'*S£  the National Technical
22161.             *'        ort  R°yal Road. Springfield, Virginia
                              ii

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                        TABLE OF CONTENTS
 1.0  INTRODUCTION .  .
      1.1 objectives  ....*.".*;;  ....... ......
      1.2 Overview of the Bakery Industry' '.  '.  ........
      1.3 Contents of this Document        ..........
      1 . 4 References  .....         * * '  .........
     2.2 Unit Operations  ...*.'.'.* ............  2-1
          2.2.1 Dough Processes  .       ...........  2~2
          2.2.2 Equipment ....." .............  2-2

                                    '
          2.3.1 Emission Sources        "  " • ......... 2-15
          2.3.2 Emission Stream Characteristics ....... 2"16
     a.4 •«-             Air              ''  '  ' ' '
          2.4.2 SCAQMD  .  .  . . ] ..............  2~21
          2.4.3 New Jersey  . ................  2-21
          2.4.4 Other Areas  . ! ." !  .............  2'22

                                                      :  :  i'-ll
     2.5
                          ................. 2-25

3.0  VOC EMISSION CONTROL DEVICES

     3.1 Combustion Control Devices  .............  3~!

         3.1.1 Direct Flame Thermal oiidation ........  •?"?"
         3.1.2 Regenerative Oxidation  . 7 .  .  .......  J-i
     -. -, M    3 Catalytic Oxidation  . .     ........  .3-2
     3.2 Noncomtaustion Control Devices    ..........  3"4
         3.2.1 carbon Adsorption ... ...........  3's
         3.2.2 Scrubbing ....     ............  3~6
         3.2.3 Condensation  !  !  ..............  3~7
         3.2.4 Biofiitration .....""""*••*•*-  -  •  3-8

    3.3 ReferencesC?S?
         4.1.1 voc Emission Factors    .....  ......   4~l

         i£l SSi SS? ^u?111^' °* s^8' :  ::::::   J:J
                               •••••••-••-  .....   4-4
                            iii

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                        TABLE OF CONTENTS

Section

          4.1.4 Oven Operating Time . 	
          4.1.5 Control Devices	
          4.1.6 Flow Rates  . . 	
          4.1.7 Bread Production  	 4-5
          4.1.8 Destruction Efficiency  	 4-5
     4.2 Costing Methodology General Assumptions  	 4-6
     4.3 Cost Analysis  ..........	 4-6
     4.4 Cost Effectiveness	
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LIST OF TABLES
Number
2-1
4-1
4-2a
4-2b
4-3a
4-3b
Representative White Pan Bread Formula

Cost of Catalytic Oxidation . . .
Cost of Regenerative Oxidation .
Cost Effectiveness of Catalytic Oxidation at
Bakery Ovens 	
Cost Effectiveness of Regenerative Oxidation
at Bakery Ovens ^ '. 	
Bgg




. 4-10

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                         LIST OF FIGURES



2-1      Tunnel  Oven ....
                              	   2-10
2-2      Single-Lap Oven ....
                              	   2-12
2-3      Spiral Oven ....
                              	   2-13
3-1      Regenerative Oxidation  .
                                      	v   3"3
3-2      Catalytic  Oxidation  .  .  .
                                      	    3-5

4-1      cost KM.BIH™... of  catalytic  Oxidation on

                              	   4-11
4-2      Coat E-F-F»rrh i wan««^ _ f  D«««-   j_ •
                            of  Regenerative Oxidation

                              "  "	   4-12
                              vi

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                            APPENDICES

Appendix

          A-l Number of Bakeries by Product CategorV*  *  '  *
              and Number of Employees  .  .  .     g ^
          A-2 Top 100 Regional Contribution To Sales "  '  '  *
          A-3 Plants by Bakery Type , Region, and state * / .'
  B       Bakery Oven Test Results '

  C       Example Calculations of cost
                                                              C-7

         BAAQMD Regulation  3 Rule 42


         SCAQMD Rule 1153 ..
                                ..............    E-l
                             vii

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                         1.0  INTRODUCTION

     The Clean Air Act Amendments (CAAA) of 1990 established new
requirements for State implementation plans (SIP) for many areas
that have not attained the national ambient air quality standards
(NAAQS) for ozone.  These requirements include an expansion of
the applicability of reasonably available control technology
(RACT) to sources of volatile organic compounds  (VOC) smaller
than those previously covered by the U.S. Environmental
Protection Agency (EPA).  They also require that certain
nonattainment -areas reduce, VOC emissions below the existing RACT
                         f
requirements to ensure Continual progress toward attainment of
the ozone NAAQS.  In addition, certain areas require a
demonstration through atmospheric dispersion modeling that VOC
emission reductions will produce ozone concentrations consistent
with the ozone NAAQS.
     To help the States  identify the kinds of VOC control that
could be used to help meet these and other requirements, the 199c
Amendments also require  EPA  to publish alternative control
technology  (ACT) documents for a variety of VOC  sources.  This
document was produced in response to a request by the baking
industry for Federal guidance to assist  in providing a more
uniform information base for State decision-making.  The
information in this document pertains to bakeries that produce
bread, rolls, buns, and  similar products, but not those that
produce crackers, pretzels,  sweet goods, or baked foodstuffs that
are not yeast-leavened.  In  this document, bread refers to yeast-
leavened pan bread, rolls, buns, or similar yeast-leavened
products unless otherwise  noted.
                                1-1

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1.1 OBJECTIVES

     One objective of this document is to provide information on
the baking process, potential emissions from baking, and
potential emission control options for use by State and local air
pollution control agencies in their analysis of new and existing
bakeries.  This can be accomplished by identifying the cost
effectiveness of controls for each oven in their area and
comparing to other facilities or industries to judge where money
might be spent'most wisely to lower emissions in the air shed.
Another important objective of this document is to provide a
predictive equation similar to an existing industry-derived
equation (described in Section 1.2), but for total VOC, using
recently gathered emission test data.
                            s
1.2 OVERVIEW OF THE BAKERY ^INDUSTRY

     About 600 large commercial bakeries produce breadstuffs in
the United States.1  Because  bread  is  perishable  and delays in
distribution to retail outlets are undesirable, bakeries are
usually located in or near population centers.  Because
population correlates with vehicular travel and other VOC
emission sources, bakeries are frequently located in ozone
nonattainment  areas.
     About 23  bakery ovens in the United states currently have
emission control devices  installed.1 Some of these are located  in
States or districts that  have rules specific to bakeries  (such as
California's Bay Area and South %oast).  The other  controlled
bakery ovens are located  in  ozone nonattainment areas where RACT
is required for major stationary sources, in ozone  attainment
areas subject  to prevention  of significant  deterioration  (PSD)
review, or at  bakeries electing to  control  voc emissions  for
other reasons.                  |
     The primary VOC emitted from bakery operation  is ethanol.
In yeast-leavened  breads, yeast metabolizes sugars  in an

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anaerobic fermentation, producing carbon dioxide that is largely
responsible for causing the bread to rise.  Besides the carbon
dioxide, eguimolar amounts of ethanol and small amounts of other
alcohols, esters, and aldehydes are produced.
     The primary emission source at a bakery is the oven.
Because the ethanol produced by yeast metabolism is generally
liquid at temperatures below 77*C (170°F), it is not emitted  in
appreciable amounts until the dough is exposed to high
temperatures in the oven.  Although high concentrations of VOC
exist in the proof boxes that are often used to raise the panned
dough, the low airflow through those boxes minimizes emissions.
     The regulation,, of VOC emissions from bakery ovens is &
recent development.  Three major studies, detailed in Section
2.3.2, have been conducted^to establish an emission factor for:
quantifying VOC emissions from bakeries.
     The first, Commercial Bakeries as a Ma "lor Source of Reactive
Volatile Organic Gases, was conducted in 1977 under an EPA
contract.'   Ethanol emissions  were calculated as  1.0  Ib/ton of
bread for straight dough and  11.2  Ib/ton of  bread for sponge
dough.
     The second study was performed by the Bay Area Air Quality
Management District  (BAAQMO)  in  San Francisco.'  After early
tests showed that  ethanol was the  primary VOC emitted, a total  of
16  ovens were tested using aqueous impingers and gas
chromatography/flame ionization.   Ethanol emissions were
calculated to range  from 0.6  to  14.0 Ib/ton  of bread.1
      The third study was performed by the American Institute of
Baking  (AIB) .'  This study was intended to explain the wide range
of  emission factors resulting from the BAAQMD study and to
provide a mathematical model  for predicting  ethanol emissions
from  bakeries.  Statistical analysis suggested that the factors
correlating best with  ethanol emissions were yeast concentration
and total fermentation time,  and that the relationship was
described as:
                                1-3

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          EtOH = 0.40425 + 0.444S85  (Yt)
where
          EtOH * pounds ethanol per ton of baked bread
          Y - baker's percent yeast
          t = total time of fermentation
This formula includes a little known correction for the addition
of spiking yeast where:
          Yt = (Yt x t,)  + (S  x t,)
and
          Yj - baker's percent yeast  in sponge
          t, -» total time of fermentation  in hours
          S  * baker's percent yiast added to dough
          t, « proof time + f }oorr time

The "percent yeast in spdnge" and "percent yeast added to dough"
are in terms of baker's percent of yeast to the nearest tenth of
a percent.  The "total time of fermentation" and "proof time +
floor time" are the fermentation times in hours to the nearest
tenth of an hour.

1.3 CONTENTS OF THIS DOCUMENT

     Typical bakery processes, equipment, operating parameters,
emission sources, emission stream characteristics, emission
estimates, techniques for determining emissions and regulations
currently affecting VOC emission^ from bakeries are described in
Chapter 2.0.   Chapter 3.0 present^ emission control techniques
that are generally used, emission control techniques that may be
effective but are not in general use, and emission control
techniques that involve transfer of technology from other
industries.  Chapter 4.0 presents, capital and annualized costs of
controlling emissions for the control techniques identified as
feasible in Chapter 3.0, guidance on methods of estimating the
                               1-4

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costs of alternative control techniques, and environmental and
energy impacts.
                              1-5

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1.4 REFERENCES

'•  BUSg"ESS SSSS.'.S'— ""••  «•—«*,,
3.
4.   wre™.. j.. a«H n^«  s. Technical Assessment Report for
                     * Ol*f*a»* i *•* /*«*MWh,_...ta.,j —  —
5.   Ref. 4.

6.
                                 Manhattan, Kansas.
                       1-6

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         2.0 INDUSTRY DESCRIPTION, PROCESSES, AND  EMISSIONS

       This chapter presents a description of the baking industry,
  regulations  currently affecting the industry,  and information on
  typical bakery unit operations including processes,  equipment;
  operating parameters,  emission sources,  and emission stream
  characteristics.
 2.1 INDUSTRY  DESCRIPTION
»                    v  .       -,..  >
      The baking dridustry  in^the United States  is  large and
 decentralized.  In 1990 th*re  were 2,636 commercial  bakeries  in
 the United States.'  As shown in Table A-l,  located in Appendix
 A, 854 bakeries produced  white pan bread, 980  produced buns and
 soft rolls, 1,097 produced variety bread, and  713 produced hearth
 bread and rolls.2  These four types  of baked goods constitute the
 bulk of the baked goods considered in this document.   As shown  in
 Table A-2', of Appendix A, the top 100 bakery companies operated
 618 plants with sales ranging  from $30 million to $2.6  billion  in
 1990.4  Aggregate  sales from these 618 bakeries was  $89.5
 billion.5  consumer expenditures for  bakery  food in  1990 ranged
 between 9 and 11 percent of all dollars spent on food consumed at
 home, with from $209 to $259 spent per year per household." Per
 capita bread  consumption in 1990 was 49.93  Ibs, and was predicted
 to increase 2.2 percent annually through 1995.7 Table A-3,  in
 Appendix A, presents  the national  distribution of  bakeries by
 type,  region,  and State.8  Because bread is perishable  and
 distribution  delays are undesirable,  the  location  of bakeries
 tends to  correlate with population and are  in larger cities in
 all states.
                               2-1

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 2.2 UNIT OPERATIONS
      The following descriptions are aggregate and composite, and
 not necessarily descriptive of a particular operation.
 Production volumes,  for example, fluctuate by daily orders,
 holidays,  and seasonal fluctuations.
 2.2.1      Douoh Processes
      Bread production at large commercial bakeries is a highly
 automated process.   When operating at full capacity,  a single
 large bread bakery  may produce up to 300,000 pounds of over 100
 different varieties of bread and other bakery products per day.
 All physical mixing and blending of ingredients,  as well as the
 working and dividing of the-doughs,  is performed  mechanically.
 Most  dough batches  are conveyed through each step of the process,
 from  the  initial dividing through the final slicing and bagging,'
 with  minimal handling.
      Four basic dough processes are used by commercial bread
 bakeries:   sponge and dough,  straight dough,  liquid ferments, and
 no-time dough.  The sponge and dough and liguid ferment methods
 are used  most often by large  commercial bakeries.   Straight
 doughs are used for a few types of  variety  breads.
      Bread in its simplest form requires four  ingredients:
 flour, water, yeast,  and  salt.   Attributes  such as  loaf volume,
 crumb softness, grain uniformity? silkiness  of texture,  crust '
 color, flavor and aroma,  softness! retention, shelf  life, and,
 most  important, nutritive  value c|n  all  be  improved by the
 addition  of appropriate optional Ingredients.  The  materials that
 are either required or may be optionally  included in the
production of various standardized bread products are  legally
defined by the Food and Drug Administration  (21 CFR Part 136).»
     A representative formula forfwhite pan bread is shown in
Table 2-1.10    TWO terms used throughout the document which are
                               2-M

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                         Table 2-1.  Representative White Pan Bread Formula"
                   Ingredients
                  I^^H
            Essential
             Flour
             Water
             Yeast
             Salt
             ^—•^^
            Optional
             Yeast food
             Sweeteners (solids)
             Shortening
             Dairy blend
             Protease enzyme
             Emulsifier
             Dough strengthener
             Preservative
              Sponge %*     Dough (Remix) %*
                65.00
                37.00
                 2.75
                 0.50
                0.25
               equals bal
          •Reference 10
35.00
27.00

  2.1
7.25
 2.3
 2.0

0.50
0.50
0.20
Total % in
 Formula
   —^—^~

   100.00
    64.00
     2.75
     2.1
     OJ50
     7,25
     2.3
     2.0
     0.25
     0.50
     0.50
:er's percent
                                             2^3
.afflj.

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unique to the bakery industry are "baker's percent*1 and
Nfermentation time".  The baker's percent of an ingredient in a
bread formula refers to the weight of that ingredient per 100
Ibs. of flour in the formula.  For a given formula, the baker's
percent of all the ingredients will total to more than 100
percent as the flour alone equals 100 baker's percent.  Table 2-1
presents a bread formula and the baker's percents  (or weights) of
each ingredient.  The total weight of flour in the formula is 100
Ibs., the total weight or baker's percent of yeast is 2.75.  The
baker's percents of all 'the ingredients in this formula totals to
182.35 baker's percent.  Fermentation time refers to the period
of time the yeast is fermenting.  The clock for fermentation time
starts when the yeast comes in contact with water  (whether it is
in a brew or dough) which pan supply it with nutrients needed fox
reproduction.  The clock^stops when the bread enters the oven.
     As about 50 percent of white pan bread produced in the
United States is made by the sponge and dough process, the
formula in Table 2-1 is shown in its adaptation to that
procedure.  In the straight dough method, a somewhat higher  yeast
level  (about 3.0 percent or more) is generally used, and all of
the  listed ingredients are processed as a single batch.  It
should also be kept in mind that individual bakers introduce
minor quantitative variations in their formulations and that the
values shown represent weighted averages.
     In the sponge and dough method, the major fermentative
action takes place  in a preferment, called the sponge,  in which
normally from 50 to 70 percent o| the total dough  flour  is
subjected to the physical, chemical, and biological actions  of
fermenting yeast.  The sponge is subsequently combined with  the
rest of the dough  ingredients to receive its final physical
development during the dough mixing or remix stage.11
     The mixed  sponge  is discharged into a greased trough  and  set
to ferment in a special fermentation room.  The  sponge
 fermentation time  normally  lasts 4.5 hours, but  may vary from  3.5
                                2-4

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hours for sponges incorporating 75 percent of the total  flour to
5 hours for sponges with only 50 percent of the total  flour.
Increased yeast levels bring about a noticeable reduction in
fermentation time.12
     The fully fermented sponge is returned to the mixer and
mixed into the final dough, which receives additional
fermentation for a short floor time  (no more than 45 minutes
under average conditions).13
     The straight dough method is a single-step process  in which
all the dough ingredients are mixed into a single batch.  The
quality of the flour/ the temperature of the mixed dough and  the
amount of yeast used•»will determine the fermentation time.14  Th<»
dough is fermented for periods- of 2 to 4 hours, with the actual
practice time being generally close to 3 hours.15  Once
fermentation begins/ the completion schedule is inflexible.16
     About 70 years ago/ efforts to simplify the sponge  and dough
method of breadmaking resulted in a stable ferment process that
replaced the sponge with a  liquid/ flour-free ferment.17   The
basic stable ferment was made of up to 70 percent water/ and
small amounts of yeast, yeast food, malt/ sugar, nonfat  dry milk,
and salt."  The resultant suspension was fermented at  a  constant
temperature for 6 hours under gentle agitation.  The mature
ferment was then either used  immediately in whole or  in  part  for
doughmaking, or it could be stored for about 48 hours, in a
stable condition/ by cooling.19
     Since the 1950's, the  stable ferment process has  been
subjected to a number of modifications and the resultant ferments
are variously referred to as  liquid  sponges, liquid  ferments,
preferments, brews or broths,  and continuous mix.20
     Although many variations  on the original  list of  ingredients
exist, flour-free  ferments  are currently often made up of 82
percent water/ and small amounts of  sweeteners/ yeast/ salt,  and
buffer salts to control the pH.21  These ferments undergo
                                2-5

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                                                                     T
fermentation for 1 to 1.5 hours while being mildly  agitated;  the
mature ferment is used or cooled.22
     In general, the time required  for the proper fermentation of
liquid ferments depends primarily on the  level  of flour in the
ferment.  Flour*-free ferments, given an appropriate set
temperature, require about 1 hour of fermentation,  whereas
                                • >v
ferments containing 40 percent flour need 2 to  2.5  hours to reach
the end point.23
     Attempts to reduce the time required before the final proof
have taken two directions:   (1) mechanical dough development
obtained by intensive high-speed mixing of dough for a short
time, and  (2) chemical dough development  in which the dough is
treated with appropriate reducing agents  and  oxidants and mixed
                    *         "' - • i s-.
at conventional speeds.  Both approaches, in  effect, eliminate
the bulk fermentation stagey €hat represents about 60 per cent of
                          •      J'i V
the total time in the traditional breadmaking process.24  These
doughs are often called no-time doughs.
     The elimination of bulk fermentation time  by mechanical
dough development usually means that these doughs require an
increase in the yeast level of  0.5  to  1.0 percent and a decrease
of 1.0 to  2.0 percent in the amount of added  sweeteners.  The
                                "'V.
production time from the  start  of mixing  to the end of baking may
be reduced to less  than 2 hours.jf-
     Chemically developed doughs are generally  referred to as
                                ','#-'>
short-time doughs  if they are subjected to bulk fermentation for
                                /)y/;','.
periods of 0.5 to  1 hour, and noftime  doughs  if they are taken
directly from the mixer to  the  divider with  no  more than 15
minutes of floor time.36   These  doughs  require an increase in the
yeast  level of  0.5  to  1.0 per cent  and a  decrease of 1.0 per cent
                                 '*••;••
in the amount of added sweeteners.  After an average fermentation
time of 30 minutes, the yeast slurry may  be  cooled or mixed as a
Straight dough.27   The production time  from the start of mixing to
the  end of baking  may be  reduced  to less  than 3 hours.28
                                2-<$

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     Following fermentation, the dough produced by any of the
above processes is divided, rounded and made up into pieces of
proper weight for intermediate proofing, moulding, final proofing
and baking.  Dividing and rounding operations subject the dough
to considerable physical abuse.29  The rounded dough balls are
given a brief rest period in an intermediate or overhead proofer.
Proofers are cabinet areas off the floor of the bakery which are
protected from drafts.  The actual proof time in practice can
last anywhere from 30 seconds to 20 minutes, although it will
usually fall within a range of 4 to 12 minutes.30  On leaving the
intermediate proofer, the dough pieces enter a moulder in which
they are shaped and moulded into a cylindrical loaf form and then
deposited in the baking pan.?1
     After the dough is deposited in the baking pan, it is ready
for final proofing in a proof box.   Proof times in practice
generally fall within a range of 55 to 65 minutes.  For the most
part, panned dough is proofed to volume or height rather than for
a fixed time.32
     After final proofing, the dough is baked in an oven.  Modern
ovens are generally designed to convey the baking loaf through a
series of zones in which it is exposed for definite time periods
to different temperature and humidity conditions.  The first
stage of baking, at a temperature of about 240°C (400° F)  lasts
about 6.5 minutes.  The second and third stages of baking
together last some 13 minutes at a constant temperature of about
238° C (460° F).  The final zone is maintained at a constant
temperature of 221 to 238° C (430 to 460° F) and the loaf baked
for about 6.5 minutes.33
     While these temperatures and durations of the individual
baking phases are representative of conventional baking practice,
considerable deviations are encountered.  Factors such as oven
design, weight or volume of product, crust character and color,
level of residual crumb moisture and others, all have a bearing on
                                2-7

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           actual baking temperature and time.  Product size  in particular
           is an important determinant of baking time.34
                These are only the basic processes.  Each bakery  employs
           variations of these basic processes to suit its production
           equipment, which is further varied for each individual type of
           product.

           2.2.2 Equipment

                2.2.2.1 Mixers.  Various mixing devices are used  to combine
           the dough ingredients.  These devices vent inside  the  bakery and
           are sources of minimal volatile  organic  compound  (VOC)
           emissions.35
                             •*        " -  1   ;,-
                          . **•'            .      -
                2.2.2.2 Fermentation.Vessels.  These are typically vats in
                                   t^       y :,-
           brew processes and  tubs in sponge processes.  The  yeast
           reproduces here  if  under  aerobic conditions; it generates carbon
           dioxide  gas, liquid ethanol, and other products if under
           anaerobic conditions.  The rooms housing these vats are humid and
           warm, and are designed to have minimal air changes.

                2.2.2.3 Intermediate Proofers.   Intermediate  proofers are
           used to  relax dough pieces for 3 to  12 minutes36 after  dividing
           and rounding and before they are moulded into  loaves.
           Intermediate proofers are generally  operated under ambient
           conditions.  The intermediate proof  time is usually between 4 and
           12 minutes.37                     j

                2.2.2.4 Proof  Boxes. Proof boxes are where  some  doughs are
           allowed to proof (rise) after being  panned.  The  proof box is a
           relatively large chamber, fabricated of  well  insulated panels and
           equipped with  temperature and humidity controls.   The  three basic
           control factors in  final  proofing are temperature, humidity, and
           time.   In practice, temperatures within  the  range of 32 to 54° C
                                           2*8.
»'•

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 (90 to 130' F)  and relative humidities of 60 to 90 percent
 encountered, with proofing temperatures of 41 to 43<* C (105 to
 HO" F) being most prevalent for bread doughs.38  Under the
 influence of the elevated temperature, the yeast activity  in the
 dough is accelerated and the loaves expand under the increasing
 pressure of carbon dioxide produced by the yeast until its
 thermal death in the oven.39  Care is taken to minimize exhausts
 from these rooms, thereby minimizing the cost of heating and
 humidifying them.  Although significant VOC concentrations have
 been measured in proof boxes, the small flow of air through them
 indicates small VOC emissions.40
                           "- i
      2.2.2.5 Ovins.  LargeBakeries typically operate from one to
 four  ovens of varying sizes, each one suited to produce certain
 types  of  breads,  buns,  rolls, and other bakery products.   All
 known  ovens burn natural gas, although some are equipped to burn
 propane as a standby fuel.   Approximately 85 to 90 percent are
 directly  fired41 by long ribbon  burners across the width of the
 oven.   Indirectly fired ovens use gun burners and separate burner
 and oven  exhausts,  allowing  for the use of fuel  such as
 distillate oil.   Indirectly  fired ovens tend to  be  found  in areas
 where  natural gas is not available,  and often are adapted for
 higher heat input after natural gas  becomes  available by  jetting
 (drilling)  the  fire tubes.   This modified  oven is sometimes
 referred  to as  a  semi-indirect-fired oven.
     Generally, large commercial  bakeries  operate one very  large
 oven for  baking high-volume products  such  as white and wheat
 breads.  Most bakeries  also have  one or more smaller ovens  for
producing buns,  rolls,  and short-run specialty breads.  There are
three basic configurations of large ovens:
 •  Tunnel Oven:    Doughs are conveyed along the length of the
                    oven from the front entrance to the
                    »«S matit'  Senerally> the oven has two or
                    more exhaust stacks (see Figure 2-1)
                               2-9

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Comfort
 Hood   —
Exhaust
                                                   Rear
                                                  Exhaust
Comfort
 Hood
Exhaust
                                  Mid
                                Exhaust
                Front
              Exhaust
                                                                        Trays
                                                                         Out
                        Figure 2-1. Tunnel oven.
                                   2-ifO

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 •  Lap Oven:       Conveyor is "lapped" so that doughs are both
                    loaded and removed at the front of the oven/
                    after travelling the length of the oven and
                    back.  Usually the oven has two or three
                    exhaust stacks (see Figure 2-2).
 •  Spiral Oven:    Conveyor path is spiraled so that doughs
                    circle the oven latitudinally several times.
                    The oven requires only a single exhaust stack
                    (see Figure 2-3).
     Ovens are often equipped with a purge stack for exhausting
residual gases in the oven prior to burner ignition.  The damper
for this stack is normally closed prior to baking.  Emissions
from these purge stacks should be very minor, and for the
purposes of control devices-and permitting, they will presumably
be treated in the same way^as other minor emission sources.
     Many ovens are also -"equipped with comfort hoods on either
end.  These devices collect air emissions from the oven that
might otherwise vent to the bakery interior.  Comfort hoods that
rely on fans rather than on convection to exhaust emissions have
a greater potential for emissions.
     When an oven is first installed, it takes approximately 2
weeks to adjust it42 and balance the airflows before it is ready
for production.  Turbulence in the exhaust airflow can cause
unstable or extinguished burner flames and non-uniform lateral
heat distribution throughout the zone.  This may result in
uneven, improperly baked bread with poor texture/ crumb
characteristics, and flavor, as well as other undesirable
characteristics.
      Some bakeries have additional baking equipment for
producing such miscellaneous items as muffins, croutons, and.
breadsticks.  This equipment differs substantially from bread
ovens and was not within the scope of this document.
      2.2.2.6  Cooling  Boxes.  After baking, bread  is  conveyed to
 an  area .to  cool.   Cooling may  take place  either on a spiral
                               2-11

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                                       Purge
                                       Stack
                     Front
                   Exhaust
    Comfort
      Hood
    Exhaust
 Trays In

Trays Out
                                                         Rear
                                                       Exhaust
   Comfort
|-  Hood
   Exhaust
                       Rgure2-2.  Single-lap oven.
                                    2-12

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f
                                                             Exhaust
                             Bread Out -
                  Trays Out
                        Trays In
"- Dough In
                                              Rgure2-3.  Spiral oven.
                                                     2-13

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conveyor or on a multi-tier looped conveyor suspended from the
ceiling.  Cooling conveyors may or may not be enclosed.

     2.2.2.7 Packaging.  After cooling, the bread is packaged for
shipping.  Some bread products are sliced before packaging.
These processes are highly mechanized.

2.2.3 Operating Parameters
     The oven is separated into several temperature  zones to
control the baking process.  In the initial zones of the oven/
the loaf rises to its final volume  (oven spring) and the yeast  is
killed, halting the fermentation reactions.  In the  middle  zones,
excess moisture and"ethanol a"reV driven off.  In the  final zones,
                 .*• '     -      , '
the crust is browned and the/sides of the loaf become  firm  enough
for slicing.  The baking process is complete when the  temperature
at the center of the loaf reaches approximately 90 to  94°C  (194
to 201*F) .*
     The operator can adjust the oven temperature to compensate
for differences between batches and bread varieties  based on
visual inspection and experience.  The temperature in  each  zone
is controlled by adjusting the burner heat output with
temperature controllers and manually adjusting the exhaust
dampers.  Constant  temperature and  laminar flow of exhaust  gases
must be maintained  across the width of the oven.
     The entire baking process is very sensitive to  upset.  By
law, white pan bread must weigh the amount stated on the package
without exceeding  38 percent moisture.44
     All equipment  must be extremely reliable to maintain high
bread quality while maintaining a tight, continuous  production
schedule.  For example, panned dough and bread are usually
transported from  one process to another, such as from  baking  to
cooling, by mechanical conveyor belts.  A conveyor shutdown may
cause the bread  in the oven to remain too long in the  oven  and  to
                               2-14

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wr'
           overheat.  If the  loaves about to go  into the oven  are delayed,
           they may rise above the size that will  fit  in the bread bags.
                Each process  unit depends on the smooth operation of the
           preceding unit,  and a breakdown  in  one  process may  affect dough
           not scheduled for  baking for several  hours.  For example,  even a
           minor malfunction  of the bag twist-tie  machine can  result in the
           loss of dough in the proof  box.  This dough cannot  be baked and
           stored or stored at temperatures low  enough to retard proofing
           because there are  rarely provisions for storage  at  any
           intermediate stage in processing.   One  cost of installing control
           equipment on a  bakery oven  is the loss  of production time while
           rebalancing  the heat flow in Jthe oven after installation of the
           control equipment.         V
                 As bread is produced ^or human consumption,  bakeries are
            required by health and safety regulations to maintain strict
            sanitary conditions.   In addition to daily cleaning,  most
            bakeries are shut down for cleaning and maintenance one or two
            days per week.

            2.3 AIR EMISSIONS

                 The major pollutants emitted from bread baking are VOC
            emissions,  chiefly the ethanol produced as a by-product of the
            leavening process, which are precursors to the formation of
            ambient ozone,  tinder aerobic conditions, yeast uses sugars added
            to the dough or converts starches in the dough to sugars for
            nutrients supporting the generation of new yeast cells.  Oxygen
            consumption during yeast reproduction produces an anaerobic
            environment.  Under anaerobic conditions, yeast ferments sugars,
            creating carbon dioxide, ethanol, and other by-products by the
            enzymatic conversion of sucrose to glucose to pyruvic acid to
            acetaldehyde to ethanol.  The yeast fermentation of 100 Ibs of
            sugar  (from either added sugar or sugar converted from starch by
            the yeast)  produces 49 Ibs ethanol, 47 Ibs carbon dioxide, and 4
            Ibs of glycerol, organic acids, aldehydes, and various minor
                                           2-15

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compounds.45  These compounds are responsible for the
characteristic flavors and aromas of bread.  The ethanol formed
in the dough is vaporized and emitted from the oven during the
end of the baking process when the internal crumb temperature
reaches the boiling point of ethanol.  Emissions of criteria
pollutants arising from combustion (oxides of nitrogen, oxides of
                               ';'
sulfur, and carbon monoxide) are comparatively small from the
typically natural gas-fired ovens.
     A few types of bread, such as corn bread and soda bread, are
chemically leavened with baking powder.  An acid/base reaction
releases carbon dioxide, raising the dough without ethanol
formation.  However, since the trace organic flavoring agents are
also not formed, the resulting bread products taste different
from conventional breads.     *

2.3.1 Emission Sources,          f

     The primary source of VOC emissions at a bakery is the oven.
Screening measurements taken at mixers, fermentation vessels,
comfort hoods, proof boxes, oven exhausts, cooling area exhausts,
and packaging areas suggest that greater than 90 percent of VOC
emissions are from the oven.44

2.3.2 Emission Stream Characteristics

     Most studies of emissions from dough and bread have been to
investigate flavor constituents, rather than to evaluate air
pollution concerns.47'48  Several studies,  however,  have been
conducted to characterize bakery air emissions.  They are
described below.                  •

     2.3.2.1 Commercial Bakeries,as a.Manor Source of Reactive
Volatile Organic Gases.  This  study, performed under an EPA
contract in 1977, represents the first attempt at estimating
                               2-16

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ethanol emissions.49  Four loaves of bread were prepared,
fermented, and baked in a small electric oven under a tent to
capture emissions from each stage of the breadmaking process.
Emissions were measured at 0.5 Ibs ethanol per 1000 Ibs bread for
the straight dough process and 5.6 Ibs ethanol per 1000 Ibs bread
for the sponge dough process.  Over 90 percent of the ethanol was
emitted during the baking.  Several other emission factors,
ranging from 5 to 8 Ibs ethanol per 1000 Ibs bread, were  also
calculated from various theoretical considerations for comparison
purposes.
     The dough formulas used differed considerably from standard
industry recipes in, both relative quantity and type of
ingredients used'.  Sweetener^ahd yeast concentrations were both
relatively high, and a standard commercial baking grade of yeast
was not used to make the test loaves.

     2.3.2.2 Bay Area Air Quality Management District  fBAAQMD)
Study.• This 1985-1986 study entailed source testing of bakery
ovens.30  In its attempt to develop more realistic emission
factors, the BAAQMD performed at least one source test using
BAAQMD Method ST-32 on every bread, bun, and roll oven at each of
the seven large commercial bakeries within the Bay Area.  A total
of 16  ovens were tested, with some tested several times under
different operating conditions.  Source emission factors,
expressed in pounds of ethanol per thousand pounds of bread, were
calculated for each test performed.  The results obtained ranged
from 0.3 to 7.0 Ibs of ethanol per 1000 Ibs of bread baked.  The
reasons for this variation of ethanol emissions were not
reported.

     2.3.2.3 American Institute of Baking  (AIB1 Study.  This  1987
study  examined the ethanol emissions data collected by the
BAAQMD.51  The purpose of this study was to explain the wide
fluctuations in levels of ethanol measured during the BAAQMD
                               2-17

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                                                                    T
survey and to look for correlations in the levels measured.   The
AIB was requested to study the relationship between the test
results and process parameters that-may affect emissions.  The
parameters studied included yeast and sweetener concentrations,
fermentation time, type of process (sponge dough vs.  straight
dough vs. brew), type of product  (white bread, buns,  sourdough
bread, variety), and baking conditions  (time  and temperature). A
linear relationship was found between emissions  (Ibs  ethanol  per
1000 Ibs bread) and the product of the  initial yeast
concentration and total fermentation and  proof time.   The dough
process type  (sponge, straight, and liquid brew) also had a small
influence.
     To confirm this relationship, AIB  derived a mathematical
model based on  the source test data.  Using the  formula developed
                   *        "" * • -J ••;;,
based on this model  (see page 1-4), an  ethanol emission factor
can be estimated for each variety of bread, and  ethanol emissions
from an oven baking breads of the varieties for which the formula
is applicable can be quantified  by multiplying the product mix by
the appropriate emission factors.

     2.3.2.4 South Coast Air Quality Management  District  fSCAOMD)
Study.  This  1988 survey was initiated  by the SCAQMD's Rule
Development Office to quantify ethanol  emissions and  determine
the number, types, and  characteristics  of bakery ovens operating
in the District.52  The  study was carried  out  using a
questionnaire designed  by  SCAQMD and distributed to bakery
operators  by the newly  formed Southern  California Baker's Air
Quality Association.  Informatioh on bakery operations was
supplied by the major bakeries  in the District.  The  quantity of
ethanol emissions reflected  in  answers  to the questionnaire was
estimated  by  the bakery owners using the  AIB  formula. Results
from the questionnaire  indicate  that there were  24 major  bakeries
operating  72  ovens  in the  Distri«3t.  Total bread production  in
                                ' '-'<£*•''
the District  was  446,700 tons pel year  and total ethanol
                               2-18

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 lick here to go
to Appendix B
  emissions  there were calculated as 4.1 tons per day.  Average
  emission rates  were calculated as 2.5 Ibs ethanol per 1000 Ibs
  bread  produced.
       The SCAQMD's Emissions Inventory Unit also attempted to
  quantify ethanol emissions generated by bread bakeries.  Based on
  their  report,  the total VOC emissions from bakeries in the South
  Coast  Air  Basin was 2442 tons per year or 9.4 tons per day.

       2.3.2.5 Current Study.  Because of increasing regulatory
  concern for certain constituents emitted in small quantities
   (such  as acetaldehyde)  from bakery oven exhausts and the need to
  predict total VOC omissions ^rather than just ethanol emissions)
  from common baking parameters', emission data were gathered.
^ Sampling and analysis was^performed using EPA Test Methods 18 (to
  quantify total organic carbon) and 25A (to speciate the
  constituents of the exhaust gas) at four typical bakeries on 18
  different products with varying yeast concentrations and
   fermentation times.  Products sampled were selected to provide a
  range  of yeast concentrations and fermentation times similar to
  the AIB study and representative of the baking industry.  A
  multiple step-wise linear regression was performed on the process
  parameters and emission rates.  The resulting data is summarized
           in Appendix B, and  indicates that total VOC  from  bakery ovens
           best be described as:
                                                                 can
                VOC  E.F. =  0.95Yi + 0.195tj - 0.51S - 0.86t, +  1.90
           where
                VOC  E.F. -  pounds  VOC  per ton  of  baked  bread
                Yj   =  initial  baker's percent of yeast to the nearest tenth
                        of a percent
                tj   =  total yeast action time in hours to the nearest tenth
                        of an hour
                S   -  final (spike) baker's percent of yeast to the nearest
                        tenth of a  percent       .
                                          2-19
1

-------
       t,    - spiking tine in hours to the nearest tenth of an
              !hAiiv»
              hour
  Although it appears that by changing a bread formula and
  inarming the amount of final yeast ,  it would be possible to
  obtain low or even a negative value for voo emission estimate!  .
  product of high quality would not be produced.-  rnLe n
  yeast  is added,  the formula condenses to:
      VOC E.F. -  0.9SY, + 0.195t, + 1.90
      This predictive eolation can be used for quantifying VOC
 «.is.10ns from bakery ovens,- A baker Know, the yeast
 concentrations and yeast artibn times for each variety baked.
 Those values can be inserted into this equation and pounds oi VOC
 per ton of bread baked can be calculated.  This number is
 and                                                    ~ P«e
 and the product is pound, of voc emitted fro, the oven for that
 particular product for the given time period (typically per
 year).   The following .option demonstrate, miscalculation :

      voc Emissions tons/yr - voc B.p.  x BP x k
 where                            :•
      VOC E.F.  . ibs VOC emissions/ton  of bread produced
      BP - bread production in tons/yr
      k  - conversion constant (ton^20001b)
    . ».3.a.6 Other manlltn.  Numerous oth« studie. of bread
emission, or con.titu.nt. have b.,» p«f ormed but are pri^rily
qualitative.  These include Roth.,- wi.ebi.tt and Kohn?«
Hironaka," El-samahy," Makuljukow^ Karkova," and others   Th«=
works discus, the relative af fect| Of baking parame^rTsuchT
proof te^erature Md bak^g timejon ratios" alders T
alcohols and other similar relationship.,  while of Lerest in
                                 <:'$.*'•. '
                              2-20

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 efforts directed at narrowing the range  of  species for which to
 analyze and minimize emissions through process modification,
 these studies relate only slightly to the quantification and
 control of total voc emissions from bakery  ovens.

 2.4 SUMMARY OF CURRENT AIR EMISSION REGULATIONS

 2.4.1 BAAOMP

      BAAQMD in 1989 adopted Regulation 8 Rule 42 (Appendix D)
 effective January i, 1992, requiring 90 percent reduction of  '
 ethanol emissions from larg* commercial bakeries.  The regulation
 exempts chemically leavened^aked goods; miscellaneous baked
 goods such as croutons,  miff fins,  crackers,  and breadsticks;
 bakeries producing less  than 100,000 Ibs per day of bread
 averaged monthly;  and ovens emitting less than 150 Ibs per day of
 ethanol.   Ovens operating before  January 1,  1933, are exempt if
 they emit no more  than 250 Ibs per day of ethanol.   Emissions are
 estimated using the AIB  formula and  measured using BAAQMD Method
 ST-32.
 2.4.2  SCAOMP
     SCAQMD  in  1990  adopted Rule  1153  -  Commercial  Bakery Ovens
regulating VOC  emissions  from bakery ovens with  a rated heat
input capacity  of  2  million BTU per hour or more (Appendix E,.
The rule requires  95 percent reduction of VOC emissions by
July 1, 1992, from new ovens emitting more than  50  Ibs  per day  of
VOC, 95 percent reduction of VOC emissions by July  i, 1994  from
ovens operating before January 1, 1991,  that emit 100 or more Ibs
of VOC per day, and  70 percent reduction of VOC  emissions by July
1, 1993, from ovens  operating before January 1,  1991, that emit
between 50 and  100 Ibs VOC per day.  Emissions are estimated
using the AIB formula and measured using EPA Test Method  25  or
SCAQMD Test Method 25.1.
                              2-21

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2.4.3 New Jersey

     The State of New Jersey regulates VOC emissions from
bakeries according to the New Jersey Administrative Code Title  7
Chapter 27 Subchapter 16.6 NSource Operations other than Storage
Tanks, Transfers, Open Top Tanks, Surface Cleaners, Surface
Coaters and Graphic Arts Operations."  This rule limits VOC
emissions to between 3.5 and 15 Ibs per hr.  Emissions estimates
and measurement are by approved methods.

2.4.4 Other Areas

     Several other State and local agencies regulate one or  more
                   V.        •"••*•• -) -':-.
of the constituents of bakery oven emissions under a general
approach such as the regulation of hazardous air pollutants.   In
the State of Washington, The Puget Sound Air Pollution Control
Agency limits ethanol emissions to levels that will not cause
ambient concentrations greater than 6000 ug/m3.60  Compliance
determination is by ambient modeling.  The state of North
Carolina limits acetaldehyde emissions to levels that will not
cause ambient concentrations greater than 27 mg/m3.61  This type
of standard is not known to have been used to require emission
reductions by a control device at a bakery.

2.4.5 Prevention of Significant Deterioration

     Areas in attainment with  National Ambient Air Quality
standards  (NAAQS)  and subject  to prevention  of significant
•deterioration  (PSD) regulations typically evaluate significant
increases  in emissions of  VOC  from a modification to  an existing
bakery or  a new bakery  (to the extent that either  is  considered a
major PSD  source,  i.e., 250 tons per year) by using  either the
AIB  formula or a source test generated  at a  similar  facility.
                               2-2?

-------
Under PSD, the level of significance is a 40 tons per year  (tpy)
increase.

2.4.6 New Sot^-ree Review

     Areas in nonattainment with ozone NAAQS and subject to new
source review (NSR) regulations typically evaluate  increased
emissions of VOC from a significant modification to an  existing
bakery or a new bakery by using either the AIB  formula  or a
source test generated at a similar facility.  Under NSR, the
level of significance is a 40 tpy increase in areas classified as
marginal or moderajte.  Modifications in areas classified as
serious, severe', or extreme/are subject to more stringent levels
for determining a  significant emissions increase.   While not the
subject of this document, the EPA is developing guidance as to
how this review will be implemented.  The major source  cutoff for
new sources ranges from 100 tons per year in an area  classified
as marginal ozone  nonattainment to 10 tons per  year in  an area
classified as extreme ozone nonattainment.  Several bakeries,
including an existing bakery in Atlanta, GA, and a  new  bakery in
Denver, PA, have been required to install VOC emission  control
devices as a result of NSR regulations.

2.4.7 Monitoring and Enforceability

     Careful record-keeping by any source of air emissions  is
essential to the determination of compliance for that source.
This is particularly true of VOC sources since  the  ozone standard
related  to VOC  emissions is of short duration compared  to other
criteria  pollutants.   Continuous emission monitoring (GEM)  is one
method used to  record  emission rates.   However, other
alternatives are available that may  be less burdensome.  These
include  but are not limited to permit  limits based on verifiable
quantities, temperature  increase across catalysts,  hot  wire
                               2-23

-------
thermistors, and various flow-based alternatives to
                        classical

2^24

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 2.5  REFERENCES

 1.    Gorman Publishing.  Gorman Red Book, 1991. Chicago. February
      1992.  p*  18.

 2.    Ref.  1, pp. 24-29.

 3.    Ref.  1, pp. 24-29.

 4.    Ref.  1, pp. 24-29.

 5.    Ref.  1, pp. 24-29.

 6.    Food  Survey Pinpoints Consumer's Bakery Buying Habits
      Bakery, p.  20.  September,  1991.   p. 20.

 7.    Anonymous.  Per  Capita Bread Consumption to Increase 2
      Percent through »96.  Milling and Baking News.  January 15,
      1991.  p.  1.           ...''

 8.    Ref.  1, p.  30.

 9.    Pylerv E. J., Baking  Science & Technology,  Sosland
      Publishing  Company. Volume II, 1988.   p.  590

 10.   Ref.  9, p.  591.

 11.   Ref.  9, p.  595.

 12.   Ref.  9, p.  596.

 13.   Ref.  9, p.  651.

 14.   Ref.  9, p.  653.

 15.   Ref.  9, p.  592.

 16.   Ref. 9, p.  593.

 17.   Ref. 9, p.  683.

 18.   Ref. 9, p.  684.

 19.  Ref. 9, p.  683.

 20.  Ref. 9, p.  684.

 21.  Ref. 9, p.  687.

22.  Ref. 9, p.  686.

23.  Ref. 9, p.  687.


                               2-25

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 2.5  References  (Continued)

 24.  Ref. 9, p.  699.


 25.  Ref. 9, p.  700.


 26.  Ref. 9, p.  703.


 27.  Ref. 9, p.  704.


 28.  Ref. 9, p.  706.


 29.  Ref. 9, pp. 709-718.


 30.  Ref. 9, pp. 718-719.


 31.  Ref. 9, pp. 719-723.


 32.  Ref. 9, p. 733.
                            ~- 7
 33.  Ref. 9, p. 741.       >y'

                          >'
 34.  Ref. 9, p. 742.



      35?'
37.  Ref.  36.


38.  Ref.  3, p.  731.


39.  Ref.  36.


40.  Ref.  35.


41.  Telecon. Sanford, w. , RTI, |fith Lanhamf  w. .  Lanham BaJcerv
     Solutions.  May s, 1992. Direct and  indirect  tS$£ ofbSery


42.  Ref.  36.                   /•;..


43.  Ref.  36.


44.  Ref.  36.                   V;J


45.  Sanderson, G., G. Reed, B. Stuinsma, and E.  J   Coooer

     J^iSl'BSlietfn^SSS9^ T"1^ ^^te^I
     1983?     Bulle^m- Manhattan, Kansas.   V.12.-4. December
                               2-26

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2.5  References (Continued)

46.  Ref. 35.

47.  Rothe, M. Aroma von Brot. Berlin, Akademie-Verlag. 1974. pp.
     10-14.

48.  Wiseblatt, L.,  F. E. Kohn. Some Volatile Aromatic Compounds
     in Fresh Bread. Washington, D.C. Presented at 44th annual
     meeting of the Quartermaster Food and Container Institute
     for the Armed Forces. Washington, D.C. May 1959. pp.  55-66.

49.  Henderson, D. Commercial Bakeries as a Major Source of
     Reactive Volatile Organic Gases. U.S. Environmental
     Protection Agency. San Francisco. December 1977. 18 pp.

50.  Cutino, J., S.ypwen. Technical Assessment Report for
     Regulation 8, Rule 42-Organic Compounds - Large Commercial
     Bakeries. Bay Area Air/Quality Management District. San
     Francisco. July 27, 1989. 34 pp.

51.  Stitley, J. W., K. E. Kemp, B. G. Kyle, and K. Kulp.  Bakery
     Oven Ethanol Emissions - Experimental and Plant Survey
     Results. American Institute of Baking. Manhattan, Kansas.
     December 1987.

52.  South Coast Air Quality Management District.  Rule 1153  -
     Commercial Bakery Ovens.  El Monte.  November 26, 1990.

53.  Doerry, Wulf T., American Institute of Baking, to Giesecke,
     A., American Bakers Association. October 8,1992. Proposed
     predictive formula.

54.  Ref.  47.

55.  Ref.  48.

56.  Hironaka, Y. Effects  of  Fermentation Conditions on Flavour
     Substances in  French  Bread Produced by the Straight Dough
     Method.  Journal of Japanese Society of Food Science and
     Technology  (Yamaguchi, Japan).  1985.

57.  El-Samahy, S.  K. Aroma of Egyptian "Baladi" Brea'd. Getreide,
     Mehl-und-Brot.  Zagazig,  Egypt.  1981.

58.  Maklyukov, V.  I.  Influence of Various Baking Methods  on  the
     Quality of Bread. Baecker-und-Konditor. Moscow.  1982.

59.  Markova,  J.  Non-enzymic  Browning Reaction  in Cereal
     Products. Sbornik-Vysoke-Skoly-Chemcko-Technologicke-v-
     Praze.  Prague.  1972.
                               2-27

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2.5  References (Continued)


":
                         X
                            2-28
                               - s-

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^p^m'
                              3.0 VOC EMISSION CONTROL DEVICES

                  Control technologies  such as  thermal  oxidation,  catalytic
             oxidation, carbon  adsorption,  scrubbing, condensation,
             biofiltration, and process changes were considered for reducing
             VOC emissions  from commercial  bakery ovens.   Devices  under
             development or not demonstrated were not considered,  although
             some show promise  for  the  future.
                  This chapter  describes emission control techniques
             potentially applicable to  yjOC  from bakeries  and identifies t^ie
 Ik           control techniques to  be evaluated in Chapter 4.0. These control
 l;|           techniques are grouped d^tfo two broad categories:  combustion
             control devices  and noncombustion  control  devices.

             3.1 COMBUSTION CONTROL DEVICES

             3.1.1 D_ir_e.ct. Flame Thermal Oxidation
  ^    ^                                  ^^-^^^H^™^^™^^^^»J
 ''-': '•' '                                                             ,        '
 '-''] '                                                                       I
  ;                3.1.1.1 Control Description.   Direct  flame thermal
  i           oxidation, also  called thermal oxidation,  is the process of
 :>j           burning organic  vapors in  a separate combustion chamber.  One
  |           type of thermal  oxidizer consists  of a refractory-lined chamber
  :           containing one or  more discrete burners that premix the organic
  '\           vapor gas stream with  the  combustion air and any required
 :'l  ,         supplemental fuel.   A  second type  of oxidizer uses a  plate-type
  \           burner firing  natural  gas  to produce a flame zone  through which
 ^           the organic vapor  gas  stream passes.   Supplemental fuel,
 \           generally natural  gas,  may be  added to the bakery  oven exhaust to
  t          make the mixture combustible if the oven exhaust has  a heating
  'I           value of less  than 1.9 MJ/m3 (50 Btu/ft3),' as is usually the case
  1          in bakery ovens.   Supplemental fuel consumption can be minimized
 I
                                             3-1

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                                                                    T
by installing a heat exchanger to recover heat from the exhaust
gas to preheat the incoming gas.
     Thermal oxidizer exhaust gas is mainly carbon dioxide and
water.  Good design and operation limit unbumed hydrocarbons and
carbon monoxide emissions to very low levels.  These design
considerations include residence time, temperature, and
turbulence in the oxidizer chamber.

     3.1.1*2 Effectiveness and Applicability of Thermal^Oxidation
to Bakery Ovens.  Oxidizers are most effective at controlling
exhaust streams with relatively high concentrations of organics.
When the oxidizer temperature is maintained at 870 °C (1600 °F)
and a residence time of 0.75 seconds, over 98 percent of the
                    v  '      "•=" • ->',
unhalogenated organic compounds' in the waste stream can be
converted to carbon dioxide^and water.**  Although VOC
concentrations in bakery exhaust can fluctuate, a thermal
oxidizer can be designed to achieve reduction efficiency greater
than 98 percent.7
     Although effective at VOC removal, the high cost of
supplemental fuel for thermal oxidizers usually makes some form
of heat recovery desirable in applications having gas exhaust
with heating values similar to bakery ovens.  Thermal oxidation
is a technically feasible but relatively  expensive technique  for
the control of VOC emissions from bakery  ovens and was  not
evaluated in Chapter 4.

3.1.2 Regenerative Oxidation

      3.1.2.1 Control Description.  Regenerative thermal oxidation
is a  variant of thermal oxidation  (see  Figure 3-1).   The  inlet
gas first passes through a hot  ceramic  bed thereby heating the
stream  (and cooling the bed) to its  ignition temperature.  If the
desired temperature is not attainable,  a  small amount of
auxiliary fuel  is added in the  combustion chamber.   The hot  gases
                                3-2

-------
                       Mode A
Aux Air
^•^
Oven —*
Exhaust
Gas "*
V
u>
Gas
Owen1 •*
i
At
Ai
i
^H
^
*
I
— »•
^-
'"
^H
t
IX
r

Heat Transfer Bed
Heating Gas

Heal Transfer Bed
Cooling Gas

Heat Transfer Bed
Cooling Gas

Heal Transfer Bed
Healing Gas
i
-^
•4
I
I *
v
Combustion
Chamber
\n»- '
\ ^
t Combustion
Chamber ^
, t •
ModaB
Figure 3-1 . Regenerative Oxidation

-------
 then react  (releasing energy)  in the combustion chamber and while
 passing through  another  ceramic  bed,  thereby heating it to the
 combustion  chamber  outlet temperature.  The  process  flows are
 then switched, now  feeding the inlet stream  to  the hot bed   Thi*
 cyclic process affords very high energy recovery (up to 95%).
      Regenerative thermal oxidizers  are available with either
 single or multiple  beds,  when a single bed  is  employed,  the bed
 is used both as  a combustion chamber  and a regenerative heat-
 recovery exchanger.  Combustion  of the air pollutant occurs  in
 the mxdsection of the single ceramic  bed.  When the  multiple beds
 are used,  the combustion chamber  is separate from the heat
 transfer beds and is equipped with a burner to provide
 supplemental heat wh^n needed.
      3.1.2.2
           to Bakery QVPT^  VOC reduction efficiencies greater
 than 98 percent are achievable.'  Regenerative oxidizers are a
 feasible control technique for control of VOC from bakery ovens
 and one xs installed at a bafcery in the United States.   The cos^
 effectiveness of a regenerative oxidizer is evaluated in chapter
                                                             r-
 4 .


 3-1.3  Catalytic
     3*1'3-1 C°»tr9l Description,  A catalytic oxidizer  is
similar to a thermal oxidizer except that combustion of  the
                                                       (see Figure
     .  This allows the oxidizer to be operated at lower
temperatures, ranging from 320 to 650°c (600 to 1200 °F)  '
consequently reducing NO, formation,  supplemental  fuel
consumption, and associated operating costs.  Temperatures below
tlus range slow the oxidation reactions resulting in lower
destruction efficiencies.  Temperatures above this range can
cause premature catalyst failure.:  where catalytic oxidation of
                               3-4

-------
                                          Catalytic Oxfdfzer
    Supplementary
         Fuel    -
in
Preheater
                                                           Catalyst Bed
                                                                                   Oven
                                                                                 o
Exhaust
   Gas
                                                                Heat
                                                             Exchanger
                                                             (Optional)
                                      Figure 3-2. Catalytic Oxidation

-------
vapor streams with a high organic content can produce
temperatures above 650 °c (1200 °F), catalytic oxidizers  can  be
suitable after dilution of those streams with fresh air.
     Catalysts are typically composed of a porous  inert  substrate
plated with metal alloy containing platinum, palladium,  copper,
chromium, or cobalt, and require an extremely clean exhaust
stream.  In early bakery applications, there was some  concern
that trace compounds and fine  particulates may  foul the  catalyst,
reducing the efficiency.  However, a catalytic  oxidizer  installed
in 1987 on a large bakery oven in the Bay Area  has been  running
trouble-free for five years.10   Although no test results  are
available at this time, advances in catalyst technology  may
eliminate the need for a preburner, thereby lowering costs.   At
least one bakery is currently  evaluating such a system.11
                    v  '      ""•» • .••*•'
                     ''
                            »nd  .
     3.1.3.2 Effectiveness ^and Applicability of Catalytic
Oxidizers to Bakery Ovens.  VOC reduction efficiencies greater
than 98 percent are achievable.12-13  Catalytic oxidation  is
considered to be technically and economically feasible.  Of the
23 known existing oxidizers on bakery ovens, 21 are of a
catalytic design.14

3.2 NONCOMBUSTION CONTROL DEVICES

3.2.1 Carbon Adsorption.

     3.2.1.1 Control Description.  A carbon adsorption unit
consists of one or more beds of activated carbon, which adsorb
organic compounds from the exhaust stream.  The organic vapors
adhere to the large surface area and when the bed becomes
saturated, steam is passed through it to regenerate the carbon.
The steam/organic vapor mix is then condensed and either sent for
disposal or distilled to recover the organic compounds.
                                3-6

-------
     3.2.1.2 Effectiveness and Applicability of Carbon Adsorption
to Bakery ovens.  Carbon adsorption is very effective in removing
low concentrations of VOC, with efficiencies greater than 95
percent.  However, there are several problems with adapting this
technology to a bakery oven.  Ethanol, the primary organic gas  in
oven exhaust, has a high affinity for carbon and is difficult to
strip from the carbon beds.  Incomplete stripping lowers bed
capacity and reduces abatement efficiency.  Fats and oils in the
exhaust may clog the carbon pores, reducing capacity and bed
life.  The resulting ethanol/water mixture would require further
treatment and disposal.  Because of these problems, carbon
adsorption is not considered for reduction of VOC emissions from
                  V ,...•" ' '   '  ""Sf-v-
bakery ovens.  ,,,  '

3.2.2 Scrubbing
       ,..,.. ,.,.*•''
     3.2.2.1 Control Description.  Scrubbing is the absorption  of
gaseous pollutants by liquid.  In a packed tower scrubber, a fine
water mist is sprayed countercurrent to the exhaust flow in the
presence of packing material with a large surface area to
maximize liquid/gas mixing.  Soluble organic compounds are
absorbed by the water and  the water/organics mixture  is either
treated for recovery of the organics or sent for disposal.

     3.2.2.2 Effectiveness and Applicability of Scrubbing to
Bakery  Ovens.   Since ethanol is readily soluble in water,
scrubbers  are technically  feasible as  a control device for VOC
removal in some applications.  Substantial quantities of water
would be required to handle the exhaust gas from bakery ovens
that would either present  a massive wastewater disposal problem
or require the  installation of large-scale wastewater treatment
that does  not simply release the  ethanol to the ambient air  or
cause other  cross-media emissions transfer, or ethanol recovery
equipment.   Due to the high costs of wastewater treatment and
                                3-7

-------
ethanol recovery, scrubbing is not considered feasible as a
technique for VOC reduction from bakery ovens.

3.2.3 Condensation

     3.2.3.1 Control, Description.  Condensation is the process  by
which pollutants are removed by cooling the gases below the  dew
point of the contaminants, causing them to condense.  Two types
of condensation devices are surface condensers and contact
condensers.
     Surface condensers are generally of a shell-and-tube design
in which the coolant  (usually water) and vapor phases are
separated by the tube wall and do not contact each other.
     Contact condensers cool"vapors by spraying a relatively cold
                ••" '      '    -y' *•
liquid into the gas stream./They are generally more efficient,
                          fT    *
inexpensive, and flexible' than surface condensers, but typically
produce large amounts of  wastewater if the condensate cannot be
recycled, and therefore,  are not considered appropriate for
bakeries.
      3.2.3.2  Effectiveness  and Applicability, of..Condensation, to
 Bakery Ovens.   Condensing the VOC gas  stream emitted by baking
 would require freon-chilled coils to cool a very  wet gas stream
 from 120  to 10 °c (250 to 50 °F).  Water would freeze on the
 coils, insulating them,  thereby  reducing the abatement efficiency
 of the system.  Fats and oils would condense more readily,
 exacerbating  any potential  sanitation  problems in the ductwork.
 However,,  the  resulting condensed liquid would'present a disposal
 problem.   Condensers are usually: associated with  airflows less
 than 2,000 ft3/min,u and most older ovens are operated  at
 substantially higher airflows.   Condensation is not considered a
                                              *
 technically feasible option for  controlling VOC emissions from
 bakeries  because most ovens are  operated at an airflow higher
 than desirable for condensers, the cost of refrigeration is high,

-------
the value of the VOC recovered is low, and the potential for
wastewater disposal problem is high.  Condensers have been not
been demonstrated to be effective VOC control devices on bakery
ovens.

3.2.4 Biofiltration

     3.2.4.1 Control Description.  Biofilters are a relatively
new, unproven technology, used in Europe for odor control and in
the United States on processes (such as yeast production) which
discharge gases at near ambient temperature.16  The exhaust stream
is passed through a* bed of sei^., which absorbs the organic
              ••' '"  ,i. •• /-    .       i
compounds.  Microorganisms naturally present in the soil break
down the organics into caroon dioxide and water.  The beds must
be monitored and kept damp to prevent cracking or insult to the
microorganisms.  This system appears to have several advantages
not offered by other control options.  The capital costs are low
enough to permit the installation of separate beds for  each stack
of a multi-stack oven.  This avoids any flow-balance problems and
minimizes the expense of  additional ducting.  Annual operating
expenses are minimal, and include minor bed maintenance and
electricity for the exhaust fan only.

      3.2.4.2 Effectiveness and Applicability of Biofiltration to
Bakery Ovens.  Because the gas stream temperature from  a bakery
oven  is higher than the temperature which soil microorganisms can
tolerate, biofiltration has not been demonstrated to be a
feasible control technique for bakery ovens.  Even if this
temperature problem were  solved by cooling the gas stream  (by
scrubbing, for example),  the wastewater and fats condensation
problems associated with  most cooling strategies are significant,
and sufficient space for  these soil beds is unavailable at many
bakeries in the United states.  The effectiveness of
biofiltration as a technique for VOC reduction from bakery ovens
                                3-9

-------
is not known.  Therefore, biofiltration is not considered  in
Chapter 4.

3.2.5 ProcessTand formulation Changes

     3.2.5.1 Contrgl Description.  The AIB study demonstrated
that shorter fermentation and lower yeast percentages do reduce
the amount of ethanol emitted.  However, these changes also
affect the taste, texture, and quality of the finished product.
It is not known if comparable products can be produced using low-
ethanol formulations.
     By substituting chemical leavening (baking powder) for the
yeast, bakers can produce bread without any ethanol formation  or
emissions.  Examples of  such oreads include corn bread and Irish
soda bread.  However, by eliminating the fermentation reactions,
the chemical leavening process also prevents formation of  the
various agents responsible for the flavors and aromas of
conventional yeast-leavened bread.  Chemically leavened breads
have their own distinct  flavor which may not be acceptable to
consumers as a substitute.
     Much research has been done to find ways to enhance the
flavor of bread prepared with short fermentation time,17 but none
has been successful.11  A major yeast manufacturer  is currently
testing an additive  intended to shorten fermentation time  and
thereby lower voc emissions,19 but initial tests have not provided
consistently acceptable  products.20

      3.2.5.2 Effectiveness and Applicability_pf process and
Formulation Changes^to JBakery .Ovens.  Process and  formulation
changes can be effective in reducing or nearly eliminating VOC
emissions from bakery ovens.  However, no modified yeast,
additive, .or enzyme  that lowers Voc emissions has  been
demonstrated to provide  taste acceptable to the baking  industry
and consumers in the United States.  Although future prospects
                               3-10

-------
are promising, process and formulation changes are not currently
feasible as a means of substantially reducing bakery VOC
emissions.
                              3-11.

-------
 3.3 REFERENCES
 3.
7.
   U. S. Environmental Protection Agency. Distillation
   SSsffiSSS&sarSa.
2.  Memorandum and attachments from Farmer J
   Environmental Protection Agency, Offic4 o

                              s
   SSSSSieS'STSSssa*
'•  aS:"^=^rsK! SM.-SK- -

8.  Ref. 3, p. 11.


9.  Ref. 1, p. 4-31.
11.  Ref. 10
                3-12

-------
           3.3  References  (Continued)
           12 '  Si voc/S^rSnmSntai,Pr0t®Ction A9ency. Parametric Evaluation
                of VOC/HAP Destruction via Catalytic Incineration  Proieet

                Summary.  Publication No. EPA/600/52-85/04!.  ReSarcS 3
                Triangle  Park, NC.  July 1985.  4 p.
           13.  U.S.  Environmental Protection Agency. Destruction of


                S! 10™?a?^ /?^dr°carbons by Catalytic Oxidation.  Publication
                No.  EPA-600/2-86-079.  Washington, DC.  September 1986? p.
                y ,                    .                                tf
|           14'   SSS; W^^MSfe.*;* gSLgS!8—tal


!           "•   5sssii,^'&isLta^
-------

-------
      4.0 IMPACT ANALYSIS OF ALTERNATIVE CONTROL TECHNIQUES

     This chapter presents the cost effectiveness of various
control strategies based on a set of model baking lines.  This
approach identifies a range of oven sizes and dough formulas
typical for the industry and derives VOC emissions and the
resulting costs of control for an oven.  Of the control methods
described in Chapter 3.0, oxidation is the most feasible and
widely used, and the control devices selected for cost analysis
are catalytic and regrenerati^e oxidizers.  The cost analysis wls
performed using the OAQPS Control cost Manual, Fourth Edition.1
Example calculations are ij^ Appendix C.
     Because the parameters affecting bakery oven emissions vary,
a range of parameters such as yeast concentration, proofing time,
oven heat input, and air flow were used, and the resulting values
for cost per ton of VOC removed and oven heat input and air flow
are displayed as summary graphs.

4.1 MODEL OVENS AND VOC EMISSIONS

     Due to the number of bakery ovens and wide variation in
process parameters affecting emissions, models were used to
represent typical baking lines.  The models are not intended to
represent all bakeries, nor any specific bakery, but rather to
summarize the range of process parameters encountered at
commercial bakeries in current operation.  Nine different size
ovens and three different dough formulas were used in the
modeling.  This approach provides 27 different representative
model baking lines for analysis  (see Table 4-1).  The parameters
chosen are optimized in some respects  and may not reflect the
mode of operation of some bakeries.  For instance, many bakeries
do not operate 24 hours per day, their schedule being driven by
                                4-1

-------
                      TABLE 4-1.  MODEL OVENS

Cue
**•
1
2
3
4
5
6
7
S
9
10
tl
12
13
14
15
16
17
18
19
20
21
22
23
24
23
26
^mM^_

Ova Size
10*BTUtr
2
3
4
S
6
7
S
9
10
2
3
4
..,--• S
6
7
8
9
10
2
3
4
5
6
7
t
9
-~—i£_^_
•^^^^^•M
Btad
Production
ftowfcrt*
5.769
1,654
11,538
14.423
17JOB
20.192
23.077
25,962
2S.S46
5,769
t«54
11.338
14.423
17,308
20.192
23J177
23.962
28,846
5,769
8,654
11.538
14,423
I7JOS
20.192
23.077
25^62
28.846
^^"•^^•1
Mwl
Yc*tt
m
125
123
123
123
123
125
133
125
125
X^
*%
4
4
4
4
4
4
4
425
4.23
423
423
423
4.25
4.25
423
^4.25
^^^••M
Spike
Ye*
(S)
0
0
0
0
0
0
0
0
0 ,
as
as
as
as
as
05
&3
03
as
0
0
0
o ,
0
0
0 !;.'
0
_0
^^f^f^^mm
YArton
Time
fti")
1.63
1.63
1.63
1.63
1.63
1.63
1.63
1.63
1.63
S.67
S.67
3.67
5.67
5.67
5.67
5.67
5.67
S.67
5.15
S.15
5.15
5.15
5.15
5.13
5.15
5.15
5.15 	
^^^«BM
Spike
Time
fti)
»^^—u_
0
0
0
0
0
0
0
0
0
us
US
us
us
us
us
US
us
us
0
0
0
0
0
0
0
0
••^^••M
••^HB^— •^^M
VOCEminaH
Fusor
fib/tail
^^^^^yjgjj**^^^^^^^^
4.4
44
44
44
44
44
4.4
4.4
44
5.4
SA
5.4
5.4
5.4
5.4
5.4
5.4
5.4
6.9
6.9
6.9
6.9
6.9
6,9
6.9
6.9
	 6.9 	
^^^^•HB
voc
EmBao
ftn . /
ffoayyi
13
19
25
32
38
44
51
57
63
16
23
31
39
47
55
62
70
78
20
30
40
SO
60
70
80
90
100
520 BTUflb bad ml 6000 tatyrpraduetiod
 dJeuluedfiompediaivefonnul.
                             4-2

-------
 orders,  holidays, and seasonal variations,  in the case of
 bakeries operating less than 24 hours per day, the decrease in
 hours means a decrease in emissions, but since the control device
 need not be operated when the oven is not baking, fuel and other
 operating costs are also reduced.  Selection of the bakery
 process  parameters is discussed below.
 4.1.1 VOC Emission Factors
      In the absence of specific source tests,  the emission of
 VOC's from bakery ovens is best described by a formula relatin
 yeast concentration,and totaO^sast action*times (mixing,
 proofing,  floor, 'and fermentation times)  to VOC emissions as
 described  in Chapter 2.0.According to this study and the AIB
 study on bakery oven ethanol  emissions,2 parameters such  as dough
 type  (spbnge,  straight,  brew),  sugar concentration in the dough,
 oven  type,  and bread type  do  not appreciably affect VOC
 emissions,   in this study  four  bakeries were tested.   The
 bakeries were  chosen to  test  a  wide variety of products
 indicative  of  the  range  in the  industry.   In this  model,  values
 for initial yeast  (yf) ,  total  yeast action time ft*) , final yeast
 (S),  and spiking time  (tj  that  are known to result in a
 marketable  product were  chosen.   These  values  reflect  the rang?
 of values found in the dough  formulas that  were tested in this
 study and,  therefore, represent  a reasonable range of  the
 industry.

 4-1.2 Oven  Type and Number- Qf staMflr*

     Model  ovens were assumed to  be directly fired by  natural gas
and have only one  stack.  Because indirectly fired ovens  make up
a small portion of  the known ovens, they are not considered.
Since the products  of combustion would presumably not  enter the
control device in  indirectly fired ovens, the flow rate to the
                               4-3

-------
 control device for  indirectly  fired  ovens would be lower and the
 control device may  be smaller,  lowering  control costs.   Oven
 design (spiral, tunnel, tray)  is not thought to affect  emission
 levels.3
      Because adjustments to exhaust  stack dampers  in a  multi-
 stack oven will change the air $low  distribution and, therefore
 the distribution of emissions from individual stacks, the need  tj>
 treat the exhaust from one or more stacks must  be  examined on a
 case-by-case basis." such  a site-specific engineering  analysis
 is beyond the scope of this document.  The analysis in this
 chapter assumes that each control technology would require an
 exhaust system ducting sufficient stacks in multi-stack ovens
 through a single plenum to^a control device, in order to achieve
 the required level of emis^on reduction. An estimate for the
 increased capital cost  o^dditjonal stacks  is $40,000  per
 stack.4                         *
 4.1.3 Oven Heat Intmt
     Oven heat  inputs  from 2  to ^10 MBtu/hr were selected in
 increments of 1 MBtu/hr.   This  i* representative of  the range  of
 heat inputs for commercial bakery ovens.   This  analysis assumes  a
 linear relationship between heat input, oven airflow,  and bread
 production, and uses heat  input ;as the independent variable-
 however, the physical  quantity  actually most affecting control
 device cost is  airflow.         |
      Oven
     All ovens were assumed to operate 24 hours per day, five
days a week (6000 hours per year| and represents common practice
in the commercial baking industrf.
                               4-4

-------
 4.1.5  Control Devices
      Of the approximately 23 ovens currently controlled, 21 use
 catalytic oxidizers,  one uses a thermal oxidizer,  and one uses a
 regenerative oxidizer.7  Cost effectiveness analyses were
 generated for catalytic and regenerative oxidizers.
 4.1.6  Flow Rates
      Flow rates  are estimated by the same mathematical model used
by the SCAQMD.8  Flow rates are calculated as a function of heat
input.  Assuming 7*3,7  Ib airwused in combusting 10,000 Btu of
natural gas,  110'^ percent theoretical air  as  supplied,  0.0808 Ib
air per cubic feet,9 and^ding the  resulting value to the 10
percent moisture10 potentially evaporated  from the white bread
dough, flow rates can  be calculated." The percent moisture loss
will  vary for other products.  The values so derived were  doubled
to compensate for the  increase in temperature and moisture.12
4.1.7 Bread Production
     Bread production is assumed to be a linear function  of heat
input.  The common design value of 520 Btu per pound of bread  is
used13 (see Table 4-1) .

4.1.8 Destruction Efficiency

     A destruction efficiency of 98 per cent is assumed,
consistent with EPA policy.14  The EPA policy maintains that 98
percent destruction efficiency is reasonable for oxidation basled
on the results of emission tests at incinerators in several
industries.  Certain existing control devices may have been
designed for a lower control efficiency, such as 95 per cent.
State or local agencies considering control of bakery VOC

                               4-5

-------
  emissions should consider allowing
                                                                usa
  4.2  COSTING METHODOLOGY GENERAL ASSDMPTIONS
                                                                      p
                                                                      i';
 costs:
           '
oost
       included  (site-spac
       is .not included);
       Dtilities are available at the  sit..
         r, ,4 p ,.,„*-' "

4.3 COST ANALYSIS
                                                 oost other
                                                Cost «»"ual is
                                           as roof "inforceaent
4.4 COST EFFECTIVENESS
                          and regenerative oxidation.  The

                              4-6

-------
Total Capital
Case Investment Natural Gas Usage
"VT -
No.
1
2
3
4
5
6
7

9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
=====
a
W (scfin) ($/yr)
$84,000
$106,000
$124,000
$140,000
$155,000
$169,000
$182,000 X '
$194,000
$206,000
SS4.000
$106,000
$124,000
$140,000
$155,000
$169,000
$182,000
$194,000
$206,000
$84,000
$106,000
$124,000
$140,000
$155,000
$169,000
$182,000
$194,000
$205,000
«az^s±^^^^5^sss±£:^^^^^5^B^^^— ^^«
Costs in this table are in 1988 dollars.
1.5
2.3
3.0
3.8
4.6
5.3
6.1
6.8
7.6
1.2
1.8
2.3
2.9
3.5
4.1
4.7
5.3
5.9
0.7
0.9
1.2
1.5
1.9
12
24
2.8
3.1
fSi^^S
Toh
$1,800
$2,700
$3,600
$4400
$5,400
$6^300^
$7^0'
JSifOO
^9,000
$1,400
$2,100
$2,800
$3400
$4,200
$4,900
$5,600
$6,300
$7,000
$800
$1,100
$1400
$1,800
$2^00
$2,600
$2,900
$3,300
$3.700
U Capital Investment c
• «»»** **w «^d"uj^«-i a\jn
Electricity Usage
(kWb/vr)
11,000
16400
22,000
27,600
33,100
38,600
44,100
49,600
55,100
11,000
16400
22,000
27400
33,100
38,600
44,100
49,600
55,100
11,000
16400
22,000
27400
33,000
38400
44,000
49400
55.000
nn be muhmlied hv
($/yr)
$700
$1,000
SUOO
$1,600
$2,000
$2,300
$2,600
$2,900
$3,300
$700
$1,000
$1,300
$1,600
$2,000
$2400
$2,600
$2,900
$3,300
$600
$1,000
$1,300
$1,600
$1,900
$2,300
$2,600
$2,900
$3.200
1 flfi te\ ntflaft 1
Total
Annual Cost
($/vr)
$36,000
$42,000
$47,000
$52,000
$56,000
$60,000
$65,000
$68,000
$72,000
$36,000
$41,000
$46,000
$51,000
$55,000
$59,000
$63,000
$67,000
$70tOOO
$351000
$40000
$45,000
$49,000
$53,000
$57,000
$60,000
$64,000
$67JOQQ
oo^Snl!!!^^5*^™
For updating Total Annual Costs, current utility rates should be verified with utility companies and the appropriate
mrrwtinn m^lixl  TU-. -Jj:^	I	^ j,        ..           . .   	      *     r            -ff«wj«M*y»
          "                 ^   "*• • "*«"*j i«»»-i ^uuuiu uc vciuicu wim unuiy companies and the appropnati

correction applied The additional cost for more than one stack has NOT been used in this calculation. Although
thi4 emet umuM KA kA0A«4 JMI A..^^. «j*« -_ j _*i_   •.       -*•   .      * .                                    & "
                                                              icti/*«
                                               _(	_^. „„. —w«p. JSUGS, «u H«Mft«adB iu wo|Jiuu UU5I. OI A*HI UUU

per stack can be used. This would translate to an aimual cost of $40,()00 multiplied by a capital recovery ^torfCRR

of0.1628andwouldequal$6412.00.
                                                 4-7

-------
TABLE 4-2b. COST OF REGENERATIVE OXIDATION'
— ^~^^^^^^^^^^^m
Case
No.
.
1
2
3
4
5
6
7
8
9
10
11
12
13
... .. . ,.«*-' '
14
15
16
17
18
19
20
21
22
23
24
25'
26
27
~ Costs in thi
Total Capital
Investment
($)
$197,000
$218,000
$234,000
$248,000
5259,000
$270,000
$279,000
$287,000
$295,000
$197,000 "
$218,000
$234,000
$248,000
5259,000
5269,000
$279,000
5287,000
5295,000
5197,000
5218,000
5234,000
$248,000
$259,000
$269,000
$279,000
$287,000
5295.000
stable are in 198
— — — «» _. —
Natural Gas Usage
fscfinl
4.4
6.6
8.7
10.9
13.1
15.3
17.5
19.7
21.8
4.0
6.0X
8.0
10.0
12.1
14.1
16.1
18.1
20.1
3.5
4.4
6.9
8.6
10.4
12.1
13.8
15.5
	 !£_
& dollars Tnt.

$5,200
STiSOO
$10,400
$13,000
$15,600
$18,200
$20,700
$23*300
$25*900
-X W.800
$7,200
$9,500
$10,300
514,300
$16,700
$19,100
$21,500
$23,900
$4,100
56^00
$8^00
$10,300
$12400
$14,400
S16,400
$18^00
$20,500
B^^q^^^i^^^^^g^^
ll ^a*»afrn) * 	 - _
— — — — __ .
Electricity Usage
(kWh/vrt
™*^^« ^i^^^J^ii
10,000
15,100
20,100
25,100
30,100
35,100
40,200
45,200
50,200
10,000
15,100
20,100
25,100
30,100
35,100
40,100
45,200
50,200
10,000
15,000
20,000
25,000
30,100
35,100
40,100
45,100
50.100
/•A-V
ta/yrj
$600
$900
SUOO
SUOO
$1,800
$2,100
$2,400
$2,700
$3,000
$600
$900
suoo
SUOO
$1,800
$2,100
$2,400
52,700
53,000
5600
$900
suoo
$1,500
$1,800
$2,100
$2,400
$2,700
$3,000
Total
Annual Cost
fft 1- V
	 flfr)
$72,000
$74,000
$85,000
$91,000
• $96,000
$101,000
$106,000
$110,000
$115,000
$71,000
$78,000
$84,000
$90,000
$95,000
$99,000
$104,000
$108,000
$113,000
$71,000
$77,000
$83,000
$88,000
$93,000
597,000
5101,000
$105,000
$109.000


-------
TABLE 4-3a. COST EFFECTIVENESS OF CATALYTIC OXIDATION AT BAKERY OVENS
Case
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27 ,
VOC Emissions
(tons/yr)4
13
19
25
32
38
44
51
57
U ' " ,,v -
1**
!* 23*
..... -31
39
47
55
62
70
78
20
30
40
50
60
70
80
90
100 .
VOC Reductions
(tons/year)
12
18
25
31
37
43
49
55
£,.-- ••• 62^-7
^
23
30
38
45
53
61
68
76
20
29
39
49
59
69
79
88
98
Bread Production
11,538.000
17308,000
23.076,000
28,846,000
34,616,000
40384.000
46.154,000
51,924,000
57,692,000
11,538,000
17308,000
23.076,000
28,846,000
34,616,000
40384,000
46,154,000
51.924.000
57,692,000
11,538,000
17308,000
23,076,000
28,846,000
34,616,000
40384,000
46,154,000
51,924,000
57,692.000
CostEfiectiv
($/tonVOC)
$2,945
$Z274
51,913
51,684
51424
51,404
$1311
51436
$1,173 ,
$2364
$1,819
$1.526
$1340
$1,210
$1.113
$1,037
$976
$925
$1,797
$1372
51,145
51,001
5901
$825
5767
$720
$681
^ 	
cness
0.0031
0.0024
0.0020
0.0011
0.0016
6.0015
0.0014
0.0013
0.0013
0.0031
KJ.0024
0.0020
0.0018
0.0016
0.0015
0.0014
0.0013
0.0012
0.0031
0.0023
0.0019
0.0017
0.0015
0.0014
0.0013
0.0012
0^0012
                                4-9

-------
TABLE 4-3b.
Case
No.
^— ^— ™».
1
2
3
4
5
6
7
8
9

10
11
12
13
14
15
16
17
18

19
20
21
22
23
24
25
26
27
VOC Emissions
ftons/vrt *
13
19
25
32
38
44
51
57
64
1 ' ' ', ff
16
23
, 	 - 31
-. ' "* J 4
39
47
55
62
70
r W
78

20
30
40
50
60

80
90
100
=™^*^^B^
VOC Reductions Bread
(tons/veart ra™* n./.~\
~-™"-» * .—
12
• M
18
f*f
25
^ f
31
• ^
37
j^
43
jfn
49
*f 'f'.
55 ;;;
1
X";
14
23
30
> 4.O
38
it f
45
*4
53 ;
£ •
61 :
68
^f
76
20 ;
in
29
^o • ^
39, .:;
jf n ' '
49
in
59
^** ' ' •
69
^n
79
oo *> '
88. , ••••f
ya
Emissions calculated from nrprfi«;,» fi.^_..,-
.^_^^___^_i«*. nayii
11,538,000
17,308,000
23,076,000
28,846,000
34,616,000
40,384,000
46,154,000
51,924,000
57,692,000
11,538,000
17,308,000
23,076,000
28,846,000
34,616,000
40,384,000
46,154,000
51,924,000
57,692,000
11,538,000
17,308,000
23,076,000
28,846,000
34,616,000
40,384,000
46,154,000
51,924,000
57.692.000
=>=s==&==^=
..
Cost Effectiveness
f $/ton VQQ ("Mb hrM
55,831 0.0062
54,186 0.0045
53,457 0.0037
52,949 0.0031
52,599 0.0028
52,342 0.0025
52,146 0.0023
51,990 0.0021
51,863 0.0020
$4,707 0.0062
$3,444 0.0045
$2,780 0.0037
$2,367 0.0031
52,083 0.0027
$1,875 0.0025
51,715 0.0023
51,589 0.0021
51,486 0.0020
$3,602 0.0061
52,527 0.0045
52,113 0.0036
51,794 0.0031
51,575 0.0027
51,414 0.0024
$1,291 0.0022
$1,193 0.0020
$1.114 O.OQ19
^ 	

-------
$0
                              Figure 4-1
       Cost Effectiveness of Catalytic Oxidation on Bakery Ovens
   2M     3M
4M
 5M     6M     7M     8M     9M     10M

Oven Heat Input (Btu/hr)
                                                                             4.4 Ib VOC/ton bread
                                                                             5.4 Ib VOC/ton bread
                                                                             7.0 Ib VOCfton bread

-------
                             Figure 4-2
Cost Effectiveness of Regenerative Oxidation on Bakery Ovens
        3M
4M     5M     6M     7M
      Oven Heat Input (Btu/hr)
                                            8M
9M     10M
                                                                       4.4 tb VOC/ton bread
                                                                       5.4 Ib VOC/ton bread
                                                                       7.0 Ib VOC/ton bread

-------
minimum, average, and maximum cost per ton of VOC removed  is
labeled on each graph.  These cost-effectiveness curves  can be
used to evaluate the cost of VOC removal for an individual oven.
     Because it is rare that an oven is dedicated exclusively to
the baking of one product, the VOC emissions for each product
typically baked in an individual oven must be estimated.   These
individual product estimates are multiplied by their annual
production tonnage and then summed to reflect actual total
emissions from the oven.  This sum should then be divided  by the
sum of the individual annual production tonnages.  This  quotient
is in pounds of VOC emissions per ton of bread.  For example:

(4.4 Ib/ton)  (1000 €ons/year)/= 4400 Ib/yr
(5.4 Ib/ton)  (2000 tons/year^ = 10800 Ib/yr
(7.0 Ib/ton)  (5000 tons/yeai;) = 35000 Ib/vr
         ,~  (8000 tons/year)   50200 Ib/yr -. 25 tons/yr

(50200 Ib/yr)/(8000 tons/yr)  =6.3 Ib/ton
                              4-13

-------
4.5 REFERENCES

1.   Vatavuk, W. M. OAQPS Control Cost Manual, Fourth Edition
     EPA 450/3-90-006. U. S. Environmental Protection Agency
     Research Triangle Park, 1990.

2.   Stitley, J. W., K. E. Kemp, B. G. Kyle, and K. Kulp.  Bakery
     Oven Ethanol Emissions - Experimental and Plant Survey
     Results. American Institute of Baking. Manhattan, Kansas.
     December, 1987. p. 11.

3.   Ref. 2, p. 11.

4.   Fischer, H., APV Baker, to Giesecke, A., American Bakers
     Association. April 22, 1991. Exhaust levels of a multi-stack
     oven.

5.   American  Instate  of Halting.  Draft:  Control of Ethanol
     Emissions from Ovens. Mar>tfattan,  Kansas. August, 1988. p. is.

6.   Frederiksen Engineering.  Study and Conceptual Cost  Estimate-
     Bakery Oven Ethanol Abatement. Oakland, California. October
     1990. ~p. 11.

7.   Telecon. W. Sanford, Research Triangle Institute (RTI), with
     T. Otchy,  CSM Environmental  Systems,  Inc. March  18,  1992
     Oxidation.

8.   South  Coast  Air  Quality  Management  District.  Rule  1153  -
     Commercial Bakery Ovens. El Monte, California, November, 1990.
     p. 32.

9.   Perry, R. H. Perry's Chemical Engineer's Handbook. New York
     McGraw-Hill. 1984. pp. 9-38.


10.  Pyler, E. J.,  Baking Science & Technology, Sosland Publishing
     Company.  Volume II, 1988.  P. 590.

11.  Telecon. Sanford,  W., RTI, with Doerry,  W., American Institute
     of Baking. August 19, 1992.  Flow  rates  in bread baking ovens.

12.  Ref. 8.

13.  Ref. 11, p.763.

14.  Memorandum from Farmer, J.R.,  U.S.  Environmental Protection
     Agency,  to  NSPS  contractors.  August  22.  1980.  Thermal
     Incineration and Flares,  p. 1.
                               4-14

-------
                       APPENDIX A
TABLES
                  IN SECTION 2.1 - INDUSTRY DESCRIPTION
                         A-l

-------
».<••
                       "'-•1

-------
                                                                -
                           Table A-1. Number off Bakeries by Product Category and Number off Employees*
Products Produced

White pan bread
Buns/soft rolls
Variety breads
Hearth breads/rolls'
Numbecs0ff Employees
1-19
75
118
147
114
•Gorman Publishing. Gorman Red Book, 1991, C
20-49
289
254
443
337
50-99
152 >
173
197
129
hicago. February
100-249
t 195
\tfs
182
80
992. pp. 24
250-499
92
90
84
38
500-1000
51
46
44
15
TOTAL
054
980
1.097
713
1-29.
U)

-------
                                                   X
III
 1

-------
        Table A-2 Top 100
Regional Contribution To Sales (%)•
Rink Compiny
1. NabiicoBnndtUSA,
Biccuit DIv.*
2. Continent Baking Co.**
3. KeeblerCo.*
4. Campbell Tiggait, Inc.**
5. General Foodi Bating
Co*v,Inc."
6. lotenuie Bakeries Corp.*
7. Hewer* Industrie*1
8. PepperidgeF«ni, Inc."
9. Sunsbloe Biicuiti, Inc.*
10. San Lee Bakery**
11. CPC International IDC. Bed
Foodi Bakine Groun*

12. Lance, Inc.
13. Mctz Baking Co.*
14 Weftoa Bakeriu Ltd*1

15. McKee Baking Co.
16.Frito-Lay,Inc.k
17. Rich Product! Cup.*
18. Stroehmann Broi. Co.1*
19. Culinir. Inc.
1990
(mil*)
2,600
1,836
1,495
1,400
1,100
1,079
782
582
540
502
500
446
434
420
395
360
350
342
330
PUnta
9
37
10
53
17
29
28
7
5
6
11
2
22
12
2
5
8
10
•L
Employee*
9,500
22.400
9,757
20,000
9,600
14,800
9,500
5,000
3,800
1,550
4,800
5,911
6,500
3,600
3,700
26,000
1,785
4,500
1,700
Routet
1,600
7,000
NA
5,100
NA
4,000
1,500
1,500
NA
NA
2,000
2,442
1,443
709
SOO*
10,000
NA
600
320
Northetrt
20
13
18
0
NA
0
0
52
NA
20
30
20
0
0
12
15
26
100
5
; Souiheart
i
15
12,
19
45
NA
>i
V
100
18
NA
20
20
59
0
0
42
25
13
0
a
Midwect
30
45
so
1
15
' NA
. / »
•J o
18
NA
30
10
8
96
0
26
25
30
0
0
Soulhwert
15
5
6
25
NA
10
0
7
NA
10
15
13
0
0
16
15
12
0
0
Wert
20
25
7
15
NA
25
0
5
NA
20
20
0
4
0
4
20
19
0
0
Caoidt
0
0
0
0
NA
0
0
0
NA
0
5
0
0
100
0
0
0
0
95

-------
Table A-2 (continued)
RukCompuy
20. The Ktofer Co.*
21. WyadhimBikinf Co. Ino.
22. Multl-Muquei. Lie.*
23f Oief Hent-
24. Sifewiy Stoni, Bikery
Dlv.«
25. Mr». Srailli'i Frozen
Food*"
26. Coiponle Foodi, Ltd.*
27.IntefbikeFoodi,Iao.
it. Tilly B^ng^ ?
29. Mrt. Biint'i Bikeriei*
30. Noflhe*ttFood^
31. Countey Home Bikery,
Inc.*
32.JJ.NiiMnB*kbgCo.<
33. Alfred Nicktei Btfceij*

34. Anhwiy Cookiet
35. Gii'i SettUe French
Biking Co.*
36. Hizelwood Fimu
B*k*riei, Inc.*
37. Lender*! Btgel B*kery
38. MeOlynn Bakeries
1990
nlei
(rail$)
311
300
268
229
225
211
200
195
? 191
175
" 159
157
151
150
140
140
140
140
140
Flints
6
8
19
2
7
6
5
4
1
11
7
5
4
5
9
2
3
4
3
Employee!
2,500
2,700
3,750
1,200
900
1,357
950
2,000
1,200
3,000
1,000
1,600
1,300
2,000
900
2,200
800
700
1.500
Route*
0
700
1,280
0
0
0
270
20
500
650
110
40
450
500
600
350
NA
80
NA
Northeut
1 o
10
0
20
0
25
4
20
80
0
80
31
100
20
20
0
20
35
5
SoudwMt
34
. 50
v 0
.-20
20
v '•
V<0
10
15
0
20
14
0
2
10
0
25
15
5
MiihiiMl
mHIWBM
57
10
0
25
0
45
6
30
5
0
0
34
0
78
50
0
21
40
70
Soudnmrt
9
20
0
20
8
10
0
0
0
100
0
6
0
0
10
0
18
0
0
Wert
0
10
0
15
72
10
0
40
0
0
0
15
0
0
10
85
16
20
20
Cioidi
0
0
100
0
0
0
90
0
0
0
0
0
0
0
0
15
0
0
0

-------
Table A-2 (continued)
Rink Compiny
39. Bahlien, Inc.
40. Chrirtle Brown Co.
41. Good Stuff Bikuy
42. Dnke Bikerief
43. Sin Fnnclico French
Bread Co.*
44. Southern Bikeriei, Inc.*
45. Mother1! Cite & Cookie
Co.*
46. Newly Wed Food), Inc.*
47. Schmidt Biking Co., Inc.*
48. Million Food*
49. Lewti Broi. Bikeriei, Inc.*
50.McaivinFoodi.Ltd*
51. Schwebel Biking Co.*
52. Smith'! Bikery, Inc.*
53. The Bichmin Co.
54. Perfection Blicutl Co., Lie.
55. Kem'i & Aim. Btkerie*
56. Klottermin Biking Co.*
57. United Stiles (Fnnz)
Bakery*
58. Alphi Biking Co.*
1990
ulc*
(mil$)
136
129
120
115
110
102
100
100
100
92
90
85
81
81
80
80
79
76
76
7i
Hint*
1
5
3
3
10
3
1
3
4
7
7
3
3
2
3
5
4
5
4

Employeei
900
1,450
1,600
1,521
1.525
982
NA
410
1,400
600
1,600
1,000
1,100
610
525
950
1,100
830
980
— — - 960
Routei
0
0
400
503
300
246
0
0
400
220
280
200
300
128
339
400
362
170
235
*30
Northeart
30
0
0
97
5
0
0
50
10
0
0
0
30
0
96
0
0
0
0
2
Sou them
I 30
0
0
3*
0
t 100
\
30
90
0
30
0
0
100
1
0
100
20
0
n
MUwe*t
30
0
0
0
t "
0
o
• /•
W 10
0
0
70
0
70
0
1
too
0
80
0
83
Southwell
5
0
0
0
5
0
0
0
0
35
0
0
0
0
0
0
0
0
0
2
Wen
5
0
too
0
75
0
100
10
0
65
0
0
0
0
1
0
0
0
100
1
Cirudi
0
100
0
0
0
0
0
0
0
0
0
100
0
0
1
0
0
0
0
0

-------
Table A-2 (continued)
Rink Company
$9. Mapbfaum, Inc.
60. F.R^Lepige Bakery, Inc.*
61. Mtlet'a Bakery*
62. Alpha Beta Bakery*


64. OoU Medal Bakery*
65.J&J9iuckFoodi
66. Giant Fooda* be., Bakery
Dhr*
67.Wcht«VBikery,lM.V
6B. Vie de Fnjtce*
69. Freih Start Bakerie*
70. Pet, bo. Bakery
Operation**
71. Eastern Bakeries, Ltd.*
72. Awrey Bakeries*
73. Grocers Biking Co.*
74. Franklin Bating Co., be.*
75. Amerfcaji Bread Co.*
76. Dough Delight, Ltd.
77. Fuchi Baking Co.*
78. Gourmet Baker, Inc.
79. Wtldensian Bakeriea, Inc.*
1990
ulea
(tnilS)
75
73
73
70
70
70
70
67
60
60
57
55
54
52
52*
51
SO
50
50
50
50
H-
2
2
2
1
1
1
3
1
-;V> ./i. 4.
13
5
4
6
1
1
4
3
2
2
8
1
Employeci
700
500
980
220
750
320
900
419
1,000
900
410
432
625
540
6S7
675
800
340
610
350
675
Routes
50
200
300
0
0
12
20
0
300
no
0
0
215
30
143
200
75
0
185
0
215
Northeast
\ 20
100
100
0
23
100
43
0
••'--•. 'V:i: 0
27
0
25
0
26
0
0
0
30
0
2
0
Souiluaat
50
0
V °
,* o
•»
" 20
0
\ ' /"
Vj.
-- - •* -• o
34
20
41
0
20
0
100
100
0
100
1
100
MJdweM
20
0
0
0
25
0
30
0
'•-•^. -- ' ' '(,-
20
0
26
0
26
100
0
0
0
0
0
0
SoUulWft
5
0
0
0
15
0
2
0
100
3
80
6
0
12
0
0
0
0
0
1
0
West
5
0
0
100
15
0
13
0
0
16
0
2
0
11
0
0
0
0
0
1
0
c—
0
0
0
0
0
0
0
0
0
0
0
0
100
5
0
0
0
70
0
95
0

-------
Table A-2 (continued)
Rank Company
80. Cnckin'Oood B»ken Irw.
81. Bcn'a Limited
82. Meyer'a Bakcriea, Inc.*
83. Schulze A Burch Biicuit
Co.
84. Mn. Alison's Cootie Co.
85. EdwMd'a Baking Co.
86. Fink Sinking Coip*
87. New Soulhweil Baking
Co.*
88. Publfac Super Mariula Inc.*
89. Seneau's Biking Co.«
90. GonneHa Baking Co.*
91.Pin-O-aoldHoluj[n
Biking Co.*


93. Buni Unlimited, too*
94. Venice Bakery*
95. Bridgford Food* Corp.
96. Unlemtlkmil Biking
97. Lucerne Foodi, Lti.*
98. Modem Maid Food
Product!, Inc.*
99. Pioneer French Baking1
1990
ulei

-------
                                                           Table  A-2   (continued)
         Rank Cbmpiny
s^sa
WO
lu
J1S)
30
17195
Fhntt
1
. Cbicigo.
Employee!
300
February 1992. m>j
Routei
NA
4-29
   10Q. Royal Cikc Co., Ino.
    mwo MiWjitiIr«. GorroinRu
 'SubiklUiyofRJR Nibiico, Ino.
 •SubiidlMyofRititonPuiirn.Ino.
 'Subiidlaiy of United BlKiiItiPLC
 •Subiidiiiy of AnheuHr-Biucb, Inc.
 'Includei Emenmina'i, too., Orowut Foodi Co., Cbii. Frelbofer BiUng Co.
 •SubiidiKy at Cimpbell Soup, Ino.
 *SubildUiy of O. P. toduuriei, be.
 ISubiJdliryofSinLecCorp
^SubiUbiy of George WeMon Ltd.
^ubildiity of Peptl Co., Inc.
"Include! only T«tyluke Go. bikeiy ulei
•Vutclwied by Culinir, ties. 31,  1990
•Fonneriy with BSN Group*
•Wboktito bakery ulei only, peadlqg ute to Yimuikl
•Fonneriy EinpKfsFoodi ltd.
'Friauiilyproducliijtbreidandiolli
                                                                             Northeail
                                                                                           Soulheut
MUmn
                                                                                                                      Somhwe*
                          Wait
                                                                                                                                           Ciudi
                                                                                                   51
                                                                                                                16
                                                                                                                                      15

-------
Table A-3.  Plants By Bakery Type, Region and State*
Region
Wholesale

Connecticut
Dist. of
Columbia
Maine
Massachusetts
New
Hampshire
New Jersey
New York
Pennsylvania
Rhode Island
Vermont
Total

26
6
17
54
. . 7 >, 	
,ff "
80
169
123
12
5
439


Illinois
Indiana
Iowa
Michigan
Minnesota
Missouri
Ohio
Wisconsin
Total
91
31
15
56
31
27
66
38
355
Grocery
Chain

0
1
0
2
- °^
j
X
1
1
0
0
5

^^fctl
3
3
0
5
3
2
5
5
26
Multi-Unit
Retail
Cookie &
Cracker/
Frozen Food
Total

5
2
0
12
1
8
19
16
0
0
63

7
0
1
17
1
30
29
36
1
2
724

38
9
18
85
r
118
218
176
13
7
691

m^^^^^n
16
4
2
16
7
2
18
10
75
30
18
4
19
9
7
25
10
122
140
56
21
96
50
38
114
6^
575
                       A-ll

-------
Table A-3 (continued)
Region

Alabama
Arkansas
Delaware
Florida
Georgia
Kentucky
Louisiana
Maryland
Mississippi
North Carolina
South Carolina
Tennessee
Virginia
West Virginia
Total

Wholesale
Grocery
Chain
Multi-Unit
Retail
Cookie &
Cracker/
Frozen Food
	 n
Total |
. ;:t
14
13
2
73
29
6
17
32
6
32
8
28
32
5
237

0
1
0
1
0
0
0
- 2 •-_
*/
4
0
0
1
0
7

0
0
0
4
3
2
3
8
0
3
1
5
2
1
32

3
6
0
13
19
6
1
4
1
11
4
11
6
2
87

17 [
20 j
2
91
51
14 j
21
46
9
46 I
13
44
41
8
423 I

::, ;,, J
Arizona
New Mexico
Oklahoma
Texas
Total
25
6
13
87
f37
1
0
0
5
e
0
1
2
6
9
3
3
3
25
34
29 I
10 ||
18
123
180
i . .,
        A-12

-------
Table A-3 (continued)
Region
Wholesale
Grocery
Chain
Multi-Unit
Retail
Cookie &
Cracker/
Frozen Food

Total
-1
Colorado
Kansas
Montana
Nebraska
North Dakota
South Dakota
Utah
Total

21
14
2
10
6
4
17 v-
74

1
2
0
0
0
0
2" ~*">~^
*/
*r
1
0
0
1
1
3
3
9

6
4 .
1
2
2
1
6
22

^AV'.
29
20
3
13
9
8
28
110

^^^fff^lWS^^^' '•• >•*:•% ^»i^».( :;"; : •'•< •>< "•<• > •-. < '*
Alaska
California
Hawaii
Idaho
Nevada
Oregon
Washington
Total
5
212
20
4
8
26
32
307
1
9
0
0
0
1
1
12
0
26
3
0
0
4
3
36
0
65
6
0
0
10
8
89
•';• - J '
••..
6
312
29
4
8
4
4
1
*
444
Region
Puerto Rico
Canada
Total no. of
plants
Wholesale
3
154
1.820
Grocery
Chain
0
2
63
Multi-Unit
Retail
2
9
235
Cookie &
Cracker/
Frozen Food
6
34
518
Total
11
199
2,636
•Gorman Publishing. Gorman Red Book, 1991. Chicago. February 1992. pp. 24-29.



                                  A-13

-------
X

-------
       APPENDIX B
*,,."
BAKERY OVEN^TEST RESULTS
y OVEJJ
           B-l

-------
•A
 n

-------

The link to the left of this box provides
§ access to a spreadsheet which
replicates the table on this page,
duplicates several calculations and also
includes regression
results that duplicate
the results which are believed were used
as the basis of predictive equation for
VOC emissions found on page 2-19 of
this report and in the AP-42 Section.
Tatpthmbcr
' InftiilYeuMYbiBH)
FnulYu4(3inBH)
Yeul Action Time (lib to)
Spiking Time (Ufa hi)
BtkcTbnefBltnmln)
Btl* Temp (BF In de» F)
W«er(H2OlnBH)
•.:• : Stigir(SpinBtt)
Oven Type
Procen
Simple Time (nun)
BieMlPtoduced(lb)
1 2 1
150 192 292


Click here to go
to Page 2-1 9

^
Bakery Oven Teali Results


V

117 2.92 217 4.25 210 100 110 111 \ 2.W 400 1 SO 2.10 150 4.00 210 ISO 1.25
0.00 0.21 021 0.21 025 025 0,00 000 000 0,00 1.00 -000 0.» 0.00 1.00 1.21 ttll 1.00 0.00 000
SOI 152 131 111 151 151 111 272 167 M l.SI 197 161 5 11 1.11 192 151 !.« 1.61 1.61
0.00 0.52 051 051 0.51 051 000 000 000 00*^ 051 ,0.00 l.ll 0.00 1.41 1.«7 120 IJ1 0.00 0.00
11.0 7.5 17.0
409 170 405
49.5 50.1 54
12 1.9 16
1 1 t
1 1 1
50 50 SO
210 200 100 190 10.5 170 125 \2I.O j. 110 201 9.0 H.O 203 6.9 19.1 2ftS 19.5
410 410 170 190 405 441 450 *» \ 450 410 500 409 401 417 390 4M 190
60 61 611 H » 64 49 tOT* 49 61 11 W.S 10* 11.1 56 51 56
03 091 II 17 0 9.6 0 0 14 47 11 ll.I 12 11 12
I II11I2I2I222I21I
j 1111 1 111 11111122
JO JO SO SO 60 SO 60 SO 60 IS 50 60 50 50 60 15 IS
IOI9I 7fi«7 1431 9111 Mil 9115 1511 5465 614S 5116 1431 4164 6199 4711 4JXS M09 1111 1997 111 711
VOC mewed (IMv) 40940 J0499 30061 27617 26760 25431 11.750 15471 14107 11031 11671 12676 I2S4I 11419 7415 »MW 4290 1.W1 1629 2041
y*,[ I779J |OJ69 10461 1174 10461 1151 11 III 7607 17000 7MO 9.711 1107 21667 1700 1161 9192 10.111 IOXBJO 5117 1675
Y*,t+S*l* 17792 10391 10609 1507 10609 149 11 III 7607 17000 7140 10366 1307 11111 7100 11167 III7S 11.011 11.111 5.717 1671
• VOC meumd Ob/Ian bf»d)
VOC-RTI predicted (IbAon brcwQ
, EtOH-AIBpfe«cled(lWlcnbi«d)
Solution ofy-nw ..+b
;
; The ETON results
presented in this table
! are based upon the AIB
developed equation
, shown on Page 1-4 of
| this document.

6261 6611 5919 5002 5216 4595 lilt S661 1.659 4561 1504 1122 1119 4061 1091 1.IM IS42 1711 5979 1116
621 410 475 416 4,75 426 696 110 517 111 419 5.IS 5.11 411 144 191 410 1.70 156 4.»
111 501 512 419 512 411 1014 179 796 1«9 SOI 41 1079 111 616 561 1.11 1.41 295 10*
6.21 410 475 426 4.75 426 6.96 1.10 517 512 419 S.I5 S.ll 4.11 144 2.91 «0 1.70 1.56 4.16


Click here to
go to Page 1-4
#





-------



-------
             APPENDIX C
EXAMPLE CALCULATIONS OF COST ANALYSIS
                 C-l

-------

-------
                   OAOPS Control Cost Analysis for Catalytic Incinerators

Section 3.4.1 •  Steps Common to Regenerative and Catalytic Units
Step 1. Establish Design Specification!
           Enter the following data corresponding to the waste gas:
           Volumetric Row Rate, scfm (77 degrees F, 1 atml
           Tamper*****' preheater inlet,  Twi
           (Assume balance oxygen composition)
           Chemical Composition of Combustibles
           enter names here->   ethanol
                                aeetaUehyde
Heating Value of Combustibles
                     ethanol
                     acetaldehyde

Enter hours per year of operation

                      ,*•;  '
           Enter the following data specific to the incinefator:
           Desired Control Efficiency (best to assume >0.90)
           Combustion Chamber Outlet Temperature
           Desired Percent-Energy Recovery, decimal
                      (choose: 0, 0.35, 0.50, or 0.70)

 Step 2. Verify that the oxygen content of the waste gas exceeds 20%.
           Air Content -
           Oxygen Content -

 Step 3. Calculate the LEL and the Percent of the LEL of the gas mixture
           Sntar the LEL of the following compounds:
                      ethanol
                      acetaldehyde

                      sum of x sub i, i equals 1 to n

           Lower Explosive Limit of the mixture equals:
           Percent LEL of the mixture equals:
                      if greater than 25%, dilution air should be addad
                      to avoid fire insurance regulations
                                                        447.00 scfm
                                                        100.00 deg, F
                                                      1,939.00 ppmv
                                                         19.39 ppmv
                   please use two most combustible
                   compounds. If less than two,
                   please enter Vs to avoid
                   division by zero errors
                                                                 2,407.00 neg.del.h sub c, BTU/scf
                                                                 2,149.00 nag.del.h sub c. BTU/scf

                                                                 6.000.00 hours/year
                                                          0.98
                                                        700.00 deg. F
                                                           0.7
                                                         99.80 Vol. %
                                                         20.86 percent
                                                          3.25 vol. %
                                                          3.97 vol. %

                                                       1,958.39

                                                     34,997.41 ppmv
                                                          5.60 percent
 Step 4. Calculate the volumetric heat of combustion of the waste gas stream
           heat of combustion,
                      ethanol
                      aoetaldehyde
           Heat of combustion for the mixture is

           Assuming waste gas is principally air (molecular
                       weight 28.97, density 0.0739 Ib/sof), then

           Heat of combustion per pound of incoming gas is
2,407.00 BTU/scf
2,149.00 BTU/scf

    4.71 BTU/scf
                                                         63.72 BTU/lb
                    32.500.00 ppmv
                    39,700.00 ppmv
           For catalytic applications the heat of combustion must normally be less
            than 10 BTU/scf (for VOC's in air).
                                                     C-2

-------
 Section 3.4.3 -  Steps Specific to Catalytic Units

 Step 5c. Establish desired outl«t temperature of the catalyst bad, Tfi

            Entmr caMyat bed ouOmt tamp.
            asaume 30O-900 dag. F for 90-95% daatruotion efficiency
            maximum tamp, of 1200 dag. F should not ba exceeded

 Stap 60. Caleulata waste gaa temperature at preheater exit

            Define the following temperatures:
                      Two, VOC straam leaving heat exchanger
                      Twi, wants gas inlet temperature
                      Tfo, flue temperature after heat exchanger
                      Tfi, catalyst chamber outlet temperature
                                 x - to be calculated
           thermal efficiency of heat exchanger -

                      Two ia therefore calculated to ba:

                      Tfo ia therefore calculated to ba:

Step 7e. Calculate tha auxiliary fuel reotfrarnj.nj, Oaf
                                                                      900.00 deg. F
                     for methane, use 21 ,502 BTU/lb jK
                     also for methane, rho - 0.040Slb,/scf   5

          Oaf is therefore calculated to be-
          this must be S positive number for burner flame stability
            Summary of Variable Valuation
            Straam                subscript j  rho sub j

            IN - Sensible Heat
            Auxiliary Air
            Auxiliary Fuel
            Waste Gas
                                    a
                                   „
                                   wo
 Q sub j
 scfm

  n/a
 O.>0
447,00
          OUT - Sensible Heat
          Waste stream
                                                                       x     deg. F
                                                                      100.00 deg. F
                                                                       x     deg. F
                                                                      900.00 dag. F

                                                                        0.70

                                                                      660.00 deg. F

                                                                      340.00 deg. F
                                                                  21,502.00 nag. del. h sub c
                                                                            sub af. BTU/lb.
                                                                       0.70 scfm
Cpm sub j   T sub j
BTU/#-F    deg. F

   n/a        n/a
not used     77    for methane
 0.248     660.00  for air
                                           0.0739     447.70     0.248
                                                                           900,00   assuming
                                                                                    primarily air
                                                     subscript
                                                        a
                                                       wo
           Energy Balance around Comfauator
           IN - Sensible Heat, rho»Q»Cp»(Ti-Tref)
                      Auxiliary Air
                      Waste Gas
           OUT - Sensible Heat
                      Waste Straam                        «
           OUT-Losses                                   fi
           ,.«,*      **" pwreont of Wai energy input
           GENERA-noj, ^a^Combusti.n, So^-(n^a,.h sub c,

                      Auxiliary Fuel                        ™ '

Step 8c. Verify that auxiliary fuel requirement will stable burner flam-

           Five percent of Total Energy input equals:
           Auxiliary Fuel Energy Input equals:                  ^.
                     Value,
                    BTU/min

                       0
                     4,776

                     6,753

                     675

                     2.105
                     617
                                                                   338 BTU/min
                                                                   817 BTU/min
                                                   C-3

-------
           If Aux. Fuel Energy Input is greater than 5% Total Enargy Input,
           burnar flame should ba stable.

Stop 9c. Estimate the inlet temperature to the catalyst bed, Tri

           Tri is calculated to be:                                      674.91 dag. F

           Delta T (temperature rise across catalyst bod) equals:          225.09 deg, F

Step 10c. Calculate total volumetric flow rate of gas through the incinerator, Qfj
           Rue Gas Row Rate, Qfi, equals:

Step 11 c. Calculate the volume of catalyst in the catalyst bed.

           Given Qfi and nominal residence time,
           catalyst volume can be calculated.
Brat, adjust Qfi to petro-chemical industry
convention of 60 deg. F, 1 atm,
                           *;*'•' "" '
Input catalyst space vslogitY in per minute
Precious metal catalysts vary: 166.67 to 1 .

Volume of catalyst bed  therefore equals: •
                                                       Qfi(SO) =>
                                                          447.70 scfm
433.53  ofm


   500  /min


  0.87  cubic feet
Section 3.5.1  - Estimating Total Capital Investment

           Scope of Cost Correlations
                                            Total (flue)
           Incinerator Type                  flow, scfm
           Fixed-bed Catalytic               2,000-50,000
           Fluid-bed Catalytic               2,000-25,000
                                                       packaged
                                                       packaged
           If Qfi is outside these parameters for the specific incinerator type,
           this costing formulation may not be used.

Section 3.5.1.1 - Equipment Costs, EC
           Catalytic Incinerators

           Total flue gas rate, Qfi
           heat recovery factor

           Fixed-Bed and Monolithic Catalytic Incinerator*
           Heat Recovery                Equipment Cost, EC
           (percent)                         1988 dollars
                    0                         $31,169
                   35                         $46,727
                   SO                         $36,518
                   70                         $42.118

           Fluid-Bad Catalytic Incinerator*
           Heat Recovery                Equipment Cost, EC
           (percent)                         1988 dollars
                    0                         $90,710
                   35                         $94,936
                   SO                         $93,674
                   70                         $92,496
                                                          447.70 scfm
                                                              70 percent
                                                        delta P
                                                       in. Water
                                                               0
                                                               4
                                                               8
                                                              IS
                                                        delta P
                                                       in. Water
                                                               0
                                                               4
                                                               8
                                                              IS
                                                         C-4

-------
 Section 3.5.1.2 - Installation Costs
           Choose Equipment Cost based on Catalytic
           Incinerator type and Heat Recovery poroent
           and enter host equipment east (EC) here ->
                                                                   $44,410
 Section 3.5.2 - Estimating Total Annual Cost

 Section 3.5.2.1 - Direct Annual Costs

           Enter the delta P, fixed-bod catalytic incinerate 161:
           Enter the delta P, fluid-bod catalytic incinerator (6-tOI:
           Enter the deita P (based on heat recovery!
                      ifrom 3.5.1.1. above)
           Number of hours/year of operation:
           Enter the combined motor/fan efficiency (decimal!:
           Enter the cost per kilowatt hour of electricity:
           Enter natural gas unit cost in tfseh
Ftxsd-Bed:Powar (fan), inWlowa,_, _^.m
Fluid-Bed: Power (fan), in kilowatts, equals

Electricity Cost, 9/yr. equals

Annual Fuel Cost:
           fMetffane assumed to be combustor fuel)
         . Rate of fuel usage
Annual Fuel Cost, in $/yr, equals
        6 in. Water
        8 in. Water
       15 in. Water

     6000 hours/year
      0.6
    0.059 9/kWh
   0.0033 $/sof

     1.83 kW
     2.01 kW

    $649  per year
    $711  per year
                                                                      0.70 scfm
                                                                     $835 per year
                                                                                      Fixed-bed
                                                                                      Fluid-bed
Total Capital Investment
           Table 3-8. page 3-S2, OAQPS Control Cost Manual (EPA 450/3-90-006, January 1990)
           Capital Cost Factors for Catalytic Incinerators
           Direct Costs
             Purchased Equipment Costs
                     Incinerator (EC) + auxiliary equipment
                     Instrumentation
                     Sales Tax
                     Freight
                     Purchased Equipment Cost, PEC

             Direct Installation Costs
                     Foundation and supports
                     Handling and erection
                     Electrical
                     Piping
                     Insulation for ductwork
                     Painting
                     Direct Installation Cost

             Enter Site Preparation  Costs
             Enter Buildings Costs

                     Total Direct Cost, DC

          Indirect Costs (Installation)
                     Engineering
                     Construction  or field expenses  ~
$44,410  as estimated.A
  $4,441  A * 0.10
  $1,332  A '0.03
  $2,220  A * 0.05
$52,404  B = 1.18 • A
 $4,192 B '0.08
 $7,33B B »0.14
 92.096 8*0.04
 $1,048 8*0.02
   5524 8*0.01
   $524 B * 0.01
$15,721  8*0.30

     $0 As required, SP
     $0 As required. Bldg.

$68,125 B * 1.30 + SP + Bldg.
 35,240  B * 0.10
 $2,620  B'O.OS
                                                         C-5

-------
                     Contractor fans
                     Start-up
                     Performance teat
                     Contingencies
                     Total Indirect Cost, 1C

           Total Capital Invaatmant =DC + 1C
                                          SS.240  B
                                          $1.048  B
                                            $524  B
                                          $1,572  B
                                         $16,245  B
                                                 0.10
                                                 0.02
                                                 0.01
                                                 0.03
                                                 0.31
                                         $84,370 B * 1.61 + SP  + Bldg.
Total Annual Coat
           Table 3.10 page 3-54, OAQPS Control Cost Manual (EPA 450/3-90-006, January 1990)
           Annual Costs for Catalytic Incinerators
             Total Capital Investment (from previous tablet
Cost Item
Direct Annual Costs, DC
   Operating Labor
     Operator
     Supervisor

   Operating materials

   Maintenance
     Labor
     Material

   Catalyst Replacement

   Utilities
     Natural Gas. $/scf
     Electricity, S/kWh

Total Direct Cost. DC

Indirect Annual Costa, 1C
   Overhead
   Admin, charges
   Property taxes
   Insurance
   Capital recovery

 Total Indirect Costs, 1C

 Total Annual Coat
        Suggested
          Factor
                                                       Unit Cost
      15%'of operator
   0.5 hrs/shift
Equals Maint. Labor

  Every 5 years
      $14.26/hour


$3SOO/cu.ft. (metal ox/del
                           $   0.0033   per scf
                           $    0.059   par kWh
    Sixty percent of sum
   of op., supv., & maim.
    labor & maint. mat'l

        TCI • 0.02
        TCI " 0.01
        TCI " 0.01
CRF tTCI -1.08 "(Cat. Cost)!
      TAG = DC + 1C
                                                $84,370

                                               Catalytic
                                               Fluid-Bed
                                                 $4,860  *
                                                   $729  *

                                                     $0
                                                     $5.348  •
                                                     $5,348  *

                                                       $607
                                                   $835
                                                   $649  Fixed-bed

                                                $18,375


                                                $14,340



                                                 $1.687
                                                   $844
                                                   $844
                                                $13,522

                                                $16,397

                                                $35,272  per year
 * based on user-provided hours/year of operation
 CRF: The capital recovery factor, CRF, is a function of the catalyst or equipment life (typically, 5 and 10
 years, respectively) and the opportunity cost of the capital (i.e., interest rate). For example, for a 10 year
 equipment life and a 10% interest rate, CRF = 0.1628.
                                                         C-6

-------

-------
                 OAQPS Control Cost Analysis for Regenerative Incinerators

 Section 3.4.1 - Steps Common to Regenerative and Catalytic Units
 Stop 1. Establish Design Specifications
           Entor the following data corresponding to tho waste gas:
           Volumetric Row Rate, scfm (77 degrees F, 1 atml
           Temperature, preheater inlet, Twi
           (Aaauma balanoa oxygen composition)
           Chamical Composition of Combustibles
           enter names here - >   ethanol
                                 acetaldehyde
           Heating Value of Combustibles
                                ethanol
                                acetaldehyde

           Enter the number of hours/year yf^oaration: " -^^

           Enter the following data specific to the incinerate^
           Desired Control Efficiency {best to assume
           Combustion Chamber Outlet Temperature
           Desired Percent Energy Recovery, decimal
                     chogae 0,  0.35, 0.50, 0.70, or 0.95

Step 2. Verify that the oxygen content of the waste gas exceeds 20%.
           Air Content -
           Oxygen Content -

Step 3. Calculate the LEL and the Parcent of the LEL of the gas mixture
           Enter the LEL of the Mowing compounds:
                     ethanol
                     ecetsfdehyde

                     sum of x sub i, i equals 1 to n

           Lower Explosive Limit of the mixture equals:
           Parcent LEL of the mixture equals:
                     if greater than 25%, dilution air should be added
                     to avoid fire insurance regulations
                                   447.00 scfm
                                   100.00 dag. F
                                 1.939.00 ppmv
                                    19.39 ppmv
                                                                                    please use two most combustible
                                                                                    compounds. If less than two,
                                                                                    please enter Vs to avoid
                                                                                    division by zaro errors
                                                                 2,407.00 nag. del. h sub c. BTU/scf
                                                                 2,149.00 nag. del. h sub c, BTU/scf

                                                                     6000 hours/year
                                                                     0.98
                                                                 1,600.00 dog. F
                                                                     0.70
                                                                    99.80 Vol. %
                                                                    20.86 percent
                                                                     3.25 vol. %
                                                                     3.97 vol. %

                                                                 1,958.39

                                                                34,997.41 ppmv
                                                                     5.60 percent
Step 4. Calculate the volumetric heat of combustion of the waste gas stream
           heat of combustion,
ethanol
acetaldehyde
           Heat of combustion for the mixture is

           Assuming waste gas is principally air (molecular
                      weight 28.97. density 0.0739 Ib/scf), then

           Heat of combustion per pound of incoming gas is

Section 3.4.2 •  Steps Specific to Regenerative Units

Stap St. Establish incinerator operating temperature, Tfi

           operating temperature (comb, chamber outlet temp.)

Step 6t. Calculate waste gas temperature at preheater exit
                                                                2,407,00 BTU/scf
                                                                2.149.00 BTU/scf

                                                                    4.71 BTU/scf
                                   63.72 BTU/lb
                                 1,600.00 dag.
                                                        32500 ppmv
                                                        39700 ppmv
                                                         C-7

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             Define the following temperatures:
                       Two, VOC stream leaving heat exchanger
                       Twl, waste gas inlet temperature
                       Tfo, flue temperature after heat exchanger
                       Tfi, incinerator operating temperature
                                  x - to be calculated

             thermal efficiency of heat exchanger -

                       Two is therefore calculated to be:

                       Tfo is therefore calculated to be:

  Step 7t. Calculate the auxiliary fuel requirement, Oaf

            Enter mxiKarf fuel heat of combustion
                       for methane, use 21,502 BTU/lb
                       also for methane, mo » 0.0408 Ib./scf

            Oaf is therefore calculated to be:

            Summary of Variable Valuation,,*          -,
            Stream              ^subscript j   mo sub j
            IN - Sensible Heat
            Auxiliary Air
            Auxiliary Fuel
            Waste Gas
                  „,,.-. „•*•••

            OUT-Sensible Heat
            Waste stream
                                     - a
                                      af
                                     wo
0.0408
0.0739
                                                       subscript

                                                           a.
                                                                       x     deg. F
                                                                      100.00 deg. F
                                                                       x     dag. F
                                                                    1,600.00 deg. F
                                                                         0.7

                                                                    1,150.00 deg. F

                                                                     550.00 deg. F
                                                                  21,502.00  neg. del. h sub c
                                                                             sub af, BTU/lb.
                                                                       3.45 Bcfm
Qsubj    Com sub j    Tsubj
 sefm     BTU/fF    deg. F

  "/«        n/a        n/a
 3.45     not used     77.00   for methane
447.00     0,255    1.150.00 for air
                                              0.0739    450.45    0.255
           Energy Balance around Combuetor
           IN - Sensible Heat, rho'Q'Cp»(TI-Tref)
                      Auxiliary Air
                      Waste Gas
           OUT - Sensible Heat                               V
                      Waste Stream                        fi
           OUT - Losses
                      ten percent of total energy input
           GENERATION -Heat of Combustion, rho*Q' •
                                                           • 'L

           If Aux. Fuel Energy Input is greater than 5% Total Energy Input
           burner flame should be stable.                        ;

Step 9t. Calculate Total Volumetric Row Rate of gas through inciner|or, Qfi

           Rue Gas Row Rate, Qfi. equals:                     J      45(MS
                               1,600.00  assuming
                                         primarily air

                                Value,
                               BTU/min

                                  0
                                9,038

                               12.928

                                1,293

                               2.105
                               3,029
                                                                      646 BTU/min
                                                                     3,029 BTU/min
Section 3.5.1- - Estimating Total Capital Investment

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           Scope of Cost Correlations

           Incinerator Type
           Thermal - regen.
           Thermal - recup.
    Total (flue)
    flow, scfm
    500-50,000
  10.000-100,000
field-erected
 packaged
           If Qfi is outside these parameters for the specific incinerator type,
           this costing formulation may not be used.

Section 3.5.1.1 - Equipment Costs, EC

           Regenerative Incinerators
           Total flue gas rate, Qfi
           heat recovery factor

           Heat Recovery
            (percent)
                    0
                  35
                  50
                  70

                  95

Section 3.S.1.2 - InstallatioA-Gosts
Equipment Cost, EC
    1988 dollars
      $43,403
 fa-* $o-4,749'^r-
      $78,672     j
      398,321  S

    $225,612
           Choose Equipment Cost based on Heat
           Recovery percent and
           inter base equipment cost IEC) hero ->
    450.45 scfm
       0.7

  delta P
 in. Water
         0
         4
         8
        15

        35
                          $103,671
Section 3.5.2 - Estimating Total Annual Cost

Section 3.5.2.1 - Direct Annual Costs

           Enter the delta Pfora regenerative incinerator 141:
           Enter the delta P (based on heat recovery)
                      (from 3.S. 1.1, above!
           Number of hours/year of operation:
           Enter the combined motor/fan efficiency (decimal!:
           inter the cost par kilowatt hour of e/ectrtcity:
           Enter natural gas unit cost in $/scf:

           Power (fan), in kilowatts, equals

           Electricity Cost,  S/yr, equals
              *
           'Annual Fuel Cost:
                      (Methane assumed to be combustor fuel)
                      Rate of fuel usage
           Annual Fuel Cost, in $/yr, equals
                                  4 in. Water
                                 15 in. Water

                              6000 hours/year
                                0.6
                              0.059 $/kWh
                            0.0033 $/scf

                               1.67 kW

                              $591  per year
                               3,45 scfm
                            94,102  per year
Total Capital Investment
           Table 3-8, page 3-52. OAQPS Control Coat Manual (EPA 450/3-90-006, January 1990)
           Capital Cost Factors for Regenerative and Catalytic Incinerators
           Direct Costa
              Purchased Equipment Costs
                                                              C-9

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                       Incinerator (EC) + auxiliary equipment
                       Instrumentation
                       Sale* Tax
                       Freight
                       Purchased Equipment Cost, PEC

               Direct Installation Costs
                       Foundation and supports
                       Handling and erection
                       Sectrical
                       Piping
                       Insulation for ductwork
                       Painting
                       Direct Installation Cost

               Enter Site Preparation Costs:
               Enter Buildings Costs:

                       Total Direct Cost, DC
                                       A*'"'"
Indirect Costs (installation)
           Engineering
           Construction or fiel^exponses
           Contractor fees
           Start-up
           Performance test
           Contingencies
           Total Indirect Cost, 1C
         „,<- ,H—''
Total Capital Investment a DC +  1C
             9103,671
              $10,367
                43,110
                $5,184
             $122,332
               $9,787
              *17,126
               $4,893
               $2,447
               $1,223
               $1,223
              $36,699
                                                                 as estimated.A
                                                                 A • 0.10
                                                                 A *0.03
                                                                 A * 0.05
                                                                 B - 1.18 * A
                                                                 8*0.08
                                                                 B'0.14
                                                                 B • 0.04
                                                                 8-0.02
                                                                 8*0.01
                                                                 8-0.01
                                                                 8*0.30
                                                             $0 As required, SP
                                                             $0 As required, Bldg.

                                                      $159.031 B  • 1.30 + SP + Bldg.
              $12,233
               $6,117
              $12,233
               $2.447
               $1,223
               $3,670
              $37,923
B * 0.10
8 * 0.05
B * 0.10
B * 0.02
B * 0.01
B * 0.03
B » 0.31
                                                                 $196,954  B * 1.61 + SP -h Bldg.
 Total Annual Cost
            Table 3.10 page 3-54. OAQPS Control Cost Manual (EPA 4SO/3-9O-006. January 1990)
            Annual Costs for Regenerative and Catalytic Incinerators
              Total Capital Investment (from previous table)
                                                                            $196.954
 Cost Item

 Direct Annual Costs, DC
   Operating Labor
     Operator
     Supervisor

   Operating materials

•  Maintenance
     Labor
     Material

   Utilities
     Natural Gas, 4/scf
     Electricity, S/kWh

Tout Direct Cost, DC
Indirect Annual Costs. 1C
  Overhead
                     Suggested
                       Factor
                    O.Shrs/shfft
                   15% of operator
                    0.5 hrs/shift
                Equal to Maim. Labor
  Unit Cost
                           Sixty percent of sum of
f14.26/hour
                                        $  0.0033  persof
                                        $   0.059   perkWh
                     Regenerative
                         $4.860
                          $729

                             $0
                        $5,348
                        $5,348
                        $4,102
                          $591

                       $20,976
                                                                             $9.770
                                                          C-10

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                          operating, supv., & maim.
                           labor & maint, materials

   Administrative charges          TCI * 0.02                -                   53 939
   Property taxas                  TCI • 0.01                                    $ l|970
   Insurance                      TCI • 0.01                                    $1*970
   Capital recovery                CRF »TCI                                    $32|o64

Total Indirect Costa, 1C                                                         $49,713

Total Annual Coat, TAG         TAC = DC + 1C                                $70,689


* based on user-provided hours/year of operation
CRF: The capital recovery factor, CRF. is a function of the equipment life (typically 10
years) and the opportunity cost of the capital (i.e., interest rate). For example, for a 10 year
equipment life and a 10% interest rate, CRF - 0.1628.
                                                           c-u

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               APPENDIX D








BAY AREA 3CER QUALITY? MANAGEMENT DISTRICT



          REGULJfflON 8 RULE 42



     LARGE COMMERCIAL BREAD BAKERIES
                  D-l

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                              REGULATION 8

                          ORGANIC COMPOUNDS

                                  RULE 42

                 LARGE COMMERCIAL BREAD BAKERIES

                                   INDEX
8-42-100  GENERAL
8-42-101
8-42-110
8-42-111
8-42-112
8-42-113
8-42-114
8-42-200

8-42-201
8-42-202
8-42-203
8-42-20V'
8-42-205
8-42-206
8-42-207
 Description
 Exemption, Small Bakeries
 Exemption. Low Emitting Ovens
 Exemption, Existing Ovens
 Exemption, Miscellaneous Bakery Products
 Exemption, Chemically Leavened Products
 DEFINITIONS
                     S
 Approved Emission Central System
 Baseline Emissions
..Bread
 Fermentation Time
 Large Commercial Bread Bakery
 Leaven
 Yeast Percentage
8-42*300  STANDARDS
8-42-301
8-42-302
8-42-303
8-42-304
 New and Modified Bakery Ovens
 Emission Control Requirements, New and Modified Ovens
 Emission Control Requirements, Existing Ovens
 Delayed Compliance, Existing Ovens
8-42-400  ADMINISTRATIVE REQUIREMENTS

8-42-401  Compliance Schedule
8-42-402  Delayed Compliance Schedule

8-42-500  MONITORING AND RECORDS (Not Included)

8-42-600  MANUAL OF PROCEDURES

8-42-601  Determination of Emissions
8-42-602  Emission Calculation Procedures
                            8-42-1
                                                  September 20,1989

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                    REGULATION 8
                 ORGANIC COMPOUNDS
                      RULE 42
            LARGE COMMERCIAL BREAD BAKERIES
                 (Adopted September 20,1989)

 8-42-100 GENERAL
 8-42-101
 8-42-110

 8-42-111
 8-42-112
 8-42-113
 8-42-114
 8-42-200 DEFINITIONS


                                           '
Exemption, Miscellaneous Bakery
8-42-201

                               **""nofral
"- -~if^Jttxs=-ss;.sxssi
-
8-42-204 Fermentation Time: Elapsed time
      and ptedng
                                    *•
                 8-42-3
                                     September 20,1989

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 8-42-205


 8*42-206
 8-42-207
 8-42-300   STANDARDS
                       "1   B-"
            b-hiry
buns, and rolls per day
 <5USi°9 9as to «««*
 * yeast per hundred
                                          EffeotiVB
                                                                         45,454
                                                           Permeate it.
                                                           1989- a
                                                               the
                                                                         subject to
                                                                               of
8-42-302
8-42-303
842-304
           301 .1 Any newly constructed oven commencing operation after January 1 , 1989
                 JSLT*?"?1"1*1 OV8° replaCing " existin9 «*» ano^commencirig
                 operation after January 1 , 1 989.
           301.3 Any existing oven which has been modified, with modifications completed
                 after January 1 , 1989, at a cost exceeding 50% of replacement cost of the
                 oven.
           301.4 Any oven with a change in production after January 1, 1989, resulting in an
                 emission increase, averaged over a 30 day period, of 68.2 kg (150 pound!)
             .    per operating day above the baseline emissions.                      f
           EmS??1- 9$*"*  Requlrwn«nts,  New and  Modified Ovens:   All new and
           modified'overis shall be required to vent all emissions to an approved emission
           control system capable otridudng emissions of precursor organic compounds bv
           90/b on a mass basis, jr
           Emission Control Requirements, Existing Ovens:  Effective January 1 1992 all
         ^existing ovens which commenced operation prior to January 1,  1989 shall' be
           required to vent emissions to a control system meeting the following standards-
           303.1  Emission collection system shall capture all emissions of precursor organi,b
                 compounds from  all oven stacks.                                   r
                 ^l!!??1 emissions shajl oe vented to an approved emission control device
                 which has a destruction efficiency of at least 90% on a mass basis.
                                *thl? °V9nK  '" H8U * ""WHO with the requirements
                            .   app"cant "^ elect to ^p1808 those ^^ «**«« i«»
                         wrth new ovens meeting the requirements of Section 8-42-302 bv
                         BSj?1 ,eleCti0n mU5t "* made *V January 1,  1991, subject to
                           ?' ln "W"0^ S"00 an election, the APCO may require the
           posting of a bond and may impose permit conditions on the existing subject ovens
           in order to assure compliance with the January 1,1994 installation of new ovens.

8-42-400   ADMINISTRATIVE REQUIREMENTS

8^2-401   Compltanw .Schedule:  Any person subject to the requirements of Section 64*
           303 of m«s rule shall comply with the following increments of progress:
           401 .1  By January 1 , 1990: Submit a status report to the APCO stating the options
           *«< *  under consideration for retrofitting or replacing existing ovens.
           401.2  By January 1, 1991: Submit a plan describing the methods proposed to be
                used to comply with 8-42-303.
                ?LlSr5 31f  1991:   Submit a «>mPleted application for any Authority to
           M *  Construct necessary to comply with these requirements.
842-402  Deate5y
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                                   Submttto^APCO a status report on the purchase of
8-42-600

8-42-601

8-42-602
  Yt*
   1.0
   1.5
   2.0
   2.5
   3.0
   3.5
   4.0
   4.5
  5.5
  6.0
  6.5
  7.0
  7.5
  8.0
  8.5
  9.0
  9.5
 10.0
 10.5
 11.0
 11.5
 12.0
 12.5
 13.0
 13.5
 14,0
 14.5
 15.0
 15.5
                                                         application for any. Authority to
            ****  »  ,       ;~:n~'	•-•/wro these requirements.
            402.4  By January 1,1994:  Be in full compliance with all applicable requirements
            MANUAL OF PROCEDURES

            Determination of Emissions:   Emissions  of organics shall  be m
            EnS£d Ctolati""81 °*PfOC8dures'Sourc8 Te* ProceduTe ST-32
            accordance with Section 8*2-601*^ nVawTab! ferlfspe'cffi^baS^"^ '"
            oven em«sions shail be calculated using the emission faclors^bS L
                                     TABLE I
Pounds VOCAon
bakery product

     .8488
    1.0711
                                                 Yt*
                                                  16.0
                                                  16.5
                                                  17.0
                      1.7380
                      15603
                      2.1826
                      2.4049
                      2.6272
                      2.8495
                      3.0718
                      3.2941
                      3.5163
                      3.7386
                      35609
                      4.1832
                      4.4055
                      4.6278
                      4.8501
                      5.0724
                      5-2947
                      53170
                     5.7393
                     55616
                     6.1839
                     6.4061
                     6.6284
                     6.8507
                     7.0730
                     7.2953
                                18.0
                                18.5
                                19.0
                                19.5
                                20.0
                                20.5
                                21.0
                                21.5
                                22.0
                               23.0
                               23.5
                               24.0
                               24.5
                               25.0
                               25.5
                               26.0
                               26.5
                               27.0
                               27J
                               28.0
                               28.5
                               29.0
                               29.5
                               30.0
*Yt
   (yeast percentage) * (fermentation time).
Pounds VOC/ton
bakery product

    7^176
    7.7399
    7.9622
    8.1845
    8.4068
    8.6291
    8.8514
    9.0737
    9.2959   -
    9.5182
    9.7405
    95628
   10.1851
   10.4074
   10.6297
   10.8520
   11.0743
   11-2966
   11.5189
   11.7412
   11.9635
   12.1857
  12.4080
  12.6303
  12.8526
  13.0749
  13.2972
  13.5195
  13.7418
                            8-42-5
                                                              September 20,1989

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                 APPENDIX E
SOUTH X20XST AIR QUALITY MANAGEMENT DISTRICT
                 RULE 1153



          COMMERCIAL BAKERY OVENS
                   E-l

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                                                   (Adopted January 4,1991)
RULE 1153.  COMMERCIAL BAKERY OVENS

(a)    Applicability
      TTiis rule controls volatile organic compound (VOC) emissions from commercial
      bakery ovens with a rated heat input capacity of 2 million BTU per hour or more
      and with an average daily emission of 50 pounds or more of VOC

(b)    Definitions  •
      For the purpose of this rule the following definitions shall apply:
      (1)    AVERAGE  DAILY EMISSIONS is the product of the total calendar
            year emjs&feras (in ton§7y$ar) divided by the number of days the oveJwas
            employed for production during that year.
      (2)    BAKERY OVENls an oven for baking bread or any other yeast leavened
         ^  products by convection.
      (3)    BASE YEAR is the calendar  1989 or any subsequent calendar year in
            which the average daily emissions are 50 pounds or more per day.
      (4)    EMISSIONS are any VOC formed and released from the oven as a result
            of the fermentation and baking processes of yeast leavened products.
     (5)    EXEMPT COMPOUNDS are any of the following compounds which
            have been determined to be non-precursors of ozone:
            (A)   Group I (General)
                   chlorodifluoromethane (HCFC-22)
                   dichlorotrifluoroethane (HCFC-123)
                   tetrafluoroethane (HFC-134a)
                   dichlorofluoroethane (HCFC-1415)
                   chlorodifluoroethane (HCFC-142b)
           (B)    Group n (Under Review)
                   methylene chloride
                   14,1-trichloroethane (methyl chloroform)
                   trifluoromethane (FC-23)
                   trichlorotrifluoroethane (CFC-113)
                   dichlorodifiuoromethane (CFC-12)
                   trichlorofluoromethane (CFC-11)
                   dichlorotetralfuoroethane (CFC-114)
                   chloropentafluoroethane (CFC-115)
                                1153-1

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 Rule 1153 (Cont.)                                     (Adopted January 4,1991)


             The Group n compounds may have restrictions on their use because they
             are toxic or potentially toxic, or upper-atmosphere ozone depleters, or
             cause other environmental impacts. The District Board has adopted a
             policy which states that chlorofluorocarbons (CFC) will be phased out at
             the earliest practicable date on or before 1997.
       (6)    EXISTING OVEN  is an oven that was constructed and commenced
             operation prior to January 1,1991.
       (7)    FERMENTATION HME is the elapsed time between adding yeast to
             the dough or sponge and placing it into the oven, expressed in hours.
       (8)    LEAVEN is to raise a dough by causing gas to permeate it
       (9)    VOLATILE ORGANIC COMPOUNDS (VOC) is any volatile chemical
             compound JhaKcontains tEe^Weraent  of carbon compound, excluding
             carbon monoxide, carbraxmoxide,  carbonic acid, metallic carbides or
             carbonates, methane, ana exempt compounds.
       (10)   YEAST PERCENTAGE is the pounds of yeast per hundred pounds of
             total recipe flour, expressed as a percentage.
 (c)    Requirements
       (1)    No person shall operate an existing bakery oven unless VOC emissions
             are reduced by at least:
             (A)   70 percent (by weight) for an oven with a base year average daily
                  VOC emissions of 50 pounds or more, but less than 100 pounds.
             (B)   95 percent by weight for an oven with a base year average daily
                  VOC emissions of 100 pounds or more.
      (2)   No person shall operate a new^ bakery oven unless VOC emissions are
            reduced by at least 95 percent by weight if the uncontrolled average daily
            VOC emissions are 50 pounds or more.
                                                                 *
(d)   Compliance Schedule
      No person shall operate a bakery oven subject to this rule unless the following
      increments of progress are met:     :j
      (1)   For bakery ovens subject to subfaragraph (c)(l)(A):
            (A)   By January 1,  1992, suDjnft required applications for permits to
                  construct and operate.  ^
                                  1153-2

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 Rule 1153 (Cont)                                      (Adopted Janoaty 4, lp91)


             (B)   By July 1, 1993,  demonstrate compliance with  subparagraph
       (2)   For bakery ovens subject to subparagraph (c)(l)(B):
             (A)   By January 1, 1993, submit required applications for permits to
                   construct and operate.
             (B)   By July  1,  1994,  demonstrate compliance with subparagraph
       (3)   For bakery ovens subject to subparagraph (c)(2) be in compliance by
             July 1, 1992 or by the date of installation, whichever is later.
 (e)    Alternate Compliance Schedule
       The subparagraphJ
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Role 1153 (Conk)                                     (Adopted January 4,1591)

(h)    Test Methods
      EPA Test Method 25, or SCAQMD Test Method 25.1, or any other method
      determined to be equivalent and approved by the Executive Officer  or  his
      designee, may be used to determine compliance with this rule.
                                 1153-4

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Rale 1153 (Cant)
                                  (Adopted January 4,1991)
                              ATTACHMENT A
 Yt'
 1.0
 15
 2.0
 25
 3.0
 35
 4.0
 4.5
 5.0
 55
 6.0
 6.5
 7.0
 15
 8.0
 85
 9.0
 9.5
10.0
105
11.0
115
12.0
125
13.0
135
14.0
15.0
155
Pounds VOC/ton
Bakery Product

      0.8488
      1.0711
      12934
      15157
      1.7380
      1.9603
      2.1826
      2.4049
 V   2.6272—* -v,
      2.8495  ,
      3.071&X
      3294T
      35163
      3.7386
      3.9609
      4.1832
      4.4055
      4.6278
      4.8501
      5.0724
      5.2947
      55170
      5.7393
      5.9616
      6.1839
      6.4061
      6.6284
      6.8507
      7.0730
      72953
 Yt'
16.0
165
17.0
175
18.0
185
19.0
195
20.0
205
21.0
215
22.0
225
23.0
235
24.0
245
25.0
255
26.0
265
27.0
275
28.0
285
29.0
295
30.0
Pounds VOC/ton
Bakery Prodi
     75176
     7.7399
     7.9622
     8.1845
     8.4068
     8.6291
     8.8514
     9.0737
     92959
     95182
     9.7405
     9.9628
    10.1851
    10.4074
    10.6297
    10.8520
    11.0743
    112966
    115189
    11.7412
    11.9635
    12.1857
    12.4080
    12.6303
    12.8526
    13.0749
    132972
    135195
    13.7418
                                                                         ct
• Yt • (yeastpercentage)x(fermentationtime)
  If yeast is added in 2 steps, Yt * (initialyeast percentage)
* (total fermentation tune) + (remaining Yeast percentage)
* (remaining fermentation time)
                                   1153-5

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                                   TECHNICAL REPORT DATA
                            fPleate read Intmcnoru OH the reverse before completing)
1. REPOBTNO.
  EPA 453/R-92-Q17
                             2.
                                                           3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
 Alternative Control Technology Document for
 Bakery Oven Emissions
                                                           S, REPORT DATE
                                                            December  1992
                                                           8. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
                                                           8. PERFORMING ORGANIZATION REPORT NQ
  C.  Wally Sanford
9. PERFORMING ORGANIZATION NAME AND ADDRESS
 Research Triangle Institute
 Post Office Box 12194
 Research Triangle Park,  NC  27709-2194
                                                           1C. PROGRAM ELEMENT NO.
                                                                        *NT NO.
                                                            68-D1-011S
12. SPONSORING AGENCY NAME AND ADDRESS
 Office  of  Air Quality Planning and Standards
 US Environmental Protection Agency
 Research Triangle ParkVNC'* 27711     "*""*
                                                           13, TYPE OF REPORT AND PERIOD COVERED
                                                            Final
                                                           14. SPONSORING AGENCY CODE
19. SUPPLEMENTARY NOTES
la. ABSTRACT
       This document was  produced in response to  a  request by the baking  industry for
  Federal guidance to assist in providing a more  uniform information base for State
  decision-making with  regard to control of bakery  oven emissions.  The information
  in the document pertains  to bakeries that produce yeast-leavened bread,  rolls,  buns,
  and similar products  but  not crackers, sweet goods,  or baked foodstuffs that are not
  yeast leavened.  Information on the baking processes, equipment, operating parameters,
  potential emissions from  baking, and potential  emission contrbl options are presented.
  Catalytic and regenerative oxidation are identified  as the most appropriate existing
  control technologies  applicable to VOC emissions  from bakery ovens.  Cost  analyses
  for catalytic and regenerative oxidation are included.  A predictive formula for use
  in estimating oven emissions has been derived from source tests done in junction
  with the development  of this document.  Its use-and  applicability are described.
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field Group
 Bakery            catalytic  oxidation
 oven            ,  regenerative oxidation
 emissions         dough  formula
 baker's percent   predictive formula
 fermentation  time
 VOC  controls
 ethanol
18. DISTRIBUTION STATEMENT
 Release  Unlimited
                                              19, SECURITY CLASS / This Report>
                                              Unclassified
21. NO. OP SA
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