United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/2-78-015
OAQPS No. 1.2-101
June 1978
Air
Guideline  Series
Control of Volatile
Organic  Emissions
from  Existing
Stationary Sources  -

Volume VI: Surface
Coating of
Miscellaneous Metal
Parts and  Products
                OTHER METAL
                COATING
                AP-42
                Section 4.2.?.^
                Reference Number

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                              EPA-450/2-78-015
                            (OAQPS No. 1.2-101)
 CONTROL OF VOLATILE ORGANIC
    EMISSIONS FROM EXISTING
       STATIONARY SOURCES
  VOLUME VI: SURFACE COATING
OF MISCELLANEOUS METAL PARTS
           AND PRODUCTS
          Emissions Standards and Engineering Division
             Chemical and Petroleum Branch
          U.S. ENVIRONMENTAL PROTECTION AGENCY
             Office of Air, Noise and Radiation
           Office of Air Quality Planning and Standards
          Research Triangle Park, North Carolina 27711

                  June 1978

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                              PREFACE

     This document is one of a series designed to inform Regional, State,
and local air pollution control agencies of techniques available for
reducing emissions of volatile organic compounds (VOC) from existing
stationary sources.  This document deals with the surface coating of
miscellaneous metal parts and products, and is intended to provide
guidance on VOC emission control for job shop and original equipment
manufacturing (OEM) industries which apply coatings on metal substrates
which have not been the subject of more specific previous documents
in this series.  Reports have already been published which identify control
options for the following industries:  can, coil, automobile and light
duty truck, metal furniture, magnet wire, and large appliances.*
      This report describes the types of coating operations found in this
broad industrial category, identifies the sources and types of VOC emissions,
and reports the available methods and costs for minimizing these emissions.
Monitoring techniques for coatings which are low in organic solvents are
suggested.  More detailed discussions of coatings low in organic solvent
and add-on control technologies are found in, "Control of Volatile Organic
Emissions from Existing Stationary Sources - Volume I:  Control Methods for
Surface Coating Operations," EPA-450/2-76-028, November, 1976.  ASTM test
methods for monitoring the organic solvent content of coatings are summarized
in, "Control of Volatile Organic Emissions from Existing Stationary Sources -
Volume II:  Surface Coating of Cans, Coils, Paper, Fabrics, Automobiles and
Light Duty Trucks," EPA-450/2-77-008, May, 1977.
*Earlier volumes in this series are available from the National Technical
Information Service.
                                   111

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                                      OAQPS GUIDELINE SERIES

The guidelines series of reports is being issued by the office of Air Quality Planning and Standards (OAQPS) to
information to state and local air pollution control agencies; for example, to provide guidance on the acquisition
and processing of air quality data and on the planning  and analysis requisite for the maintence of air quality.
Reports published in this series will be available - as supplies permit - from the Library Services Office (MD-35),
U.S. Environmental  Protection Agency, Research Triangle Park, North Carolina 27711; or, for a nominal fee, from
the National Technical  Information Service, 5285 Port Royal Road, Springfield, Virginia 22161.
                                     Publication No. EPA-450/2-78-015

                                            (OAQPS No. 1.2-101)

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      The miscellaneous metal  part and product category includes hundreds
of small to medium size  industries for which writing individual guideline
documents would be impractical.  After reviewing these industries,  EPA
prepared this report to assist local agencies in determinq the  level of VOC
control that represents the presumptive norm that can be achieved through
the application of reasonably available control technology (RACT).   Reasonably
available control technology is defined as the lowest emission limit that a
particular source is capable of meeting by the application of control
technology that is reasonably available considering technological and
economic feasibility.  It may require technology that has been applied to
similar, but not necessarily identical source categories.  It is not
intended that extensive research and development be conducted before a
given control technology can be applied to the source.  This does not,
however, preclude requiring a short-term evaluation program to permit
the application of a given technology to a particular source.  This latter
effort is an appropriate technology forcing aspect of RACT.  The diagram
on the next page provides emission limits that represent RACT for the
industries included in the miscellaneous metal parts and products category
of the surface coating industry.
      It must be cautioned that the limits reported in the diagram are necessarily
based on a general consideration of the capabilities and problems of the
hundreds of industries which coat their products.  It will not be applicable
to every plant or even every industry within the many industries which
coat.  For example, the level of control which is herein recommended for
a particular source may be based on a type of coating which cannot meet
the specifications required of another product from a similar source.
                                   IV

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                        Manufacture of Metal  Parts and Products
Air or forced air-dried items:
Parts too large or too heavy for
practical size ovens and/or sensi-
tive heat requirements.  Parts to
which heat sensitive materials are
attached.  Equipment assembled
prior to too coating for specific
performance or quality standards.
0.42 kg/liter (3.5 Ibs/gal)
   No or infrequent color chanae,
   or small number of colors
   applied.
                      Clear  Coat
         0.52  kg/liter
         (4.3  Ibs/gal)
    owder
    oatings
   J.05 kg/liter
   p.4  Ibs/gal
Outdoor or harsh
exposure or extreme
performance
characteristics
0.42 kg/liter
(3.5 Ibs/gal)
Frequent color change and/
or large number of colors
applied, or first coat on
untreated ferrous substrate
0.36 kg/liter
(3.0 Ibs/qal)
                                    Logic diagram for derivation of emission
                        limits for coatina of miscellaneous metal parts and
                        products.

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      The recommended emission limits are based on the use of coatings
low in organic solvents.  They range from 0.05 to 0.52 Kg per liter
(0.4 to 4.4 Ibs/gal).  Equivalent reductions in VOC emissions can be achieved
by the use of add-on control devices such as incinerators and carbon adsorbers.
Many coating applicators, however, have expressed that they plan to meet
future VOC regulations through the use of coatings low in organic solvents
rather than resort to add-on control devices.

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                           GLOSSARY


Single coat means only one film of coating is applied to the metal
substrate.

Prime coat means the first of two or more films of coating applied
in an operation.

Topcoat means the final film or series of films of coating applied  in
a two-coat (or more) operation.

Faraday caging means a repelling force generated in corners and small
enclosed areas of the metal substrate during electrostatic spraying of
powders.

Blocking agent means an organic agent which blocks or inhibits certain
cross-linking or polymerization reactions.  It is designed to separate
from the monomer at some elevated temperature thereby allowing the
reactions to proceed.

Low organic solvent coating (LOSC) refers to coatings which contain
less organic solvent than the conventional coatings used by the industry.
Low organic solvent coatings include water-borne, higher solids,
electrodeposition and powder coatings.

Heat sensitive material means materials which cannot be exposed to
temperatures greater than 80° to 95°C (180° to 200°F).

Transfer efficiency means the portion of coating which is not lost or
wasted during the application process expressed as percent.
                               vn

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                    CONVERSION FACTORS FOR METRIC UNITS

                                                                   Equivalent
Metric Unit                       Metric Name                     English Unit

Kg                          kilogram (103grams)                      2.2046 Ib
liter                       liter                                    0.0353 ft3
dscm                        dry standard cubic meter                35.31 dry std. ft.
        3                                                                   3
scmm  (Mm )                  standard cubic meter per min.           35.31 ft /min.
Mg                          megagram (10 grams)                     2,204.6 Ib
metric ton                  metric ton (10 grams)                   2,204.6 Ib
Gj                          gigajoules ( 109joules)                 9.486 x 105BTU
    In keeping with U.S. Environmental Protection Agency policy, metric units
are used in this report.  These units may be converted to common English units
by using the above conversion factors.
    Temperature in degrees Celsius (C°) can be converted to temperature in
degrees Fahrenheit  (°F) by the following formula:

    t°f = 1.8 (t°c) + 32

    t f = temperature in degrees Fahrenheit

    t   = temperature in degrees Celsius or degrees Centigrade
    Kg.  per  liter  x  8.34 =  Ibs/gal
                                      vm

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                         TABLE OF CONTENTS


PREFACE	   ii
GLOSSARY	    V
CONVERSION FACTORS FOR METRIC UNITS 	   vi
1.0  SOURCES AND TYPES OF EMISSIONS	   1-1
     1.1  General Discussion	   1-1
     1.2  Processes and Emission Points 	   1-4
2.0  APPLICABLE SYSTEMS OF EMISSION REDUCTION 	   2-1
     2.1  Water-Borne (Spray, Dip or Flow Coat)	   2-2
     2.2  Water-Borne (Electrodeposition) 	   2-2
     2.3  Higher-Solids Coatings	   2-4
     2.4  Powder Coatings	   2-5
     2.5  Carbon Adsorption 	   2-6
     2,6  Incinerators	   2-8
     2.7  References	   2-10
3.0  COST ANALYSIS	   3-1
     3.1  Introduction	   3-1
          3.1.1  Purpose	   3-1
          3.1.2  Scope	   3-1
          3.1.3  Use of Model Plants	   3-2
          3.1.4  Bases for Capital Cost Estimates	   3-3
          3.1.5  Bases for Annualized Costs  	   3-3
     3.2  Solvent Emission Control in Metal Coating Operations.  .  .  .   3-4
          3.2.1  Model Plant Parameters 	   3-4
          3.2.2  Control Costs	   3-7
     3.3  Cost Effectiveness	   3-15
     3.4  Summary	   3-24
     3.5  References	   3-25
     3.6  Bibliography	   3-25
4.0  DETERMINATION OF APPLICABLE EMISSION LIMITATIONS  	   4-1
     References	   4-4

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5.0  ADVERSE AND BENEFICIAL EFFECTS OF APPLYING TECHNOLOGY	   5-1
     5.1  Water-Borne (Spray, Dip, or Flow Coat)	   5-1
     5.2  Water-Borne (Electrodeposition) 	   5-2
     5.3  Higher Solids Coatings	   5-4
     5.4  Powder Coatings	   5-4
     5.5  Carbon Adsorption 	 ...........   5-6
     5.6  Incineration.	   5-7
     5.7  References	   5-11
6.0  MONITORING TECHNIQUES AND ENFORCEMENT ASPECTS	   6-1
APPENDIX A - SAMPLE CALCULATIONS OF CONTROL OPTIONS .-	   A-l
APPENDIX A - Reference.	   A-4

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                     1.0  SOURCES AND TYPES OF EMISSIONS

    This chapter provides general information  on  the  miscellaneous metal
parts and products  industries, the methods by which  conventional  coatings
are applied, and the volatile organic compound (VOC)  emissions which can be
expected from the coatings.
1.1  GENERAL DISCUSSION
    A wide variety of metal parts and products are coated for decorative or
protective purposes.  These are grouped into hundreds of small industrial
categories for which writing individual guideline documents would be
unreasonable.  This guideline document is intended to provide information on
industries which coat metal parts and products, with the exception of the can,
coil, magnet wire, automobiles and light duty truck,  metal  furniture and large appliance
industries.  These have been reported previously in "Control of Volatile Organic
Emissions from Existing Stationary Sources - Volumes II, III, IV, and V."
    The "industrial categories for which this guideline is intended and some
examples of each category are listed in Table  1.1,
    There are far more dissimilarities than similarities between both the many
plants and various industries represented by this category.  For example, the
geographic distribution of these industry categories is market-dependent and
varies greatly.  Some industries such as large farm machinery are located
primarily in agricultural areas of the country such as EPA Regions V and
VII.  Others, like small appliances may be scattered throughout the country
                                     1-1

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      Table 1.1   LIST OF  INDUSTRIAL CATEGORIES  COVERED  BY

                       THIS GUIDELINE DOCUMENT3
'  large farm machinery (harvesting, fertilizing and planting machines, tractors,
  combines, etc.)

"  small farm machinery (lawn and garden tractors,  lawn mowers,  rototillers,
  etc.)

"  small appliances (fans, mixers, blenders,  crock  pots, dehumidifiers,
  vacuum cleaners, etc.)

*  commercial machinery (computers and auxiliary equipment,  typewriters,
  calculators, vending machines, etc.)

'  industrial machinery (pumps, compressors,  conveyor components,  fans,
  blowers, transformers, etc.)

*  fabricated metal products (i.e., metal covered  doors, frames).

"  any other industrial category which coats  metal  parts or  products under
  the Standard Industrial Classification Code of  Major Group 33 (primary
  metal industries),  Major Group 34 (fabricated metal products),  Major
  Group 35 (non-electrical machinery), Major Group 36 (electrical machinery),
  Major Group 37 (transportation equipment), Major Group 38 (miscellaneous
  instruments), Major Group 39 (miscellaneous manufacturing industries),
  Major Group 40 (railroad transportation) and Major Group  41  (transit
  passenger transportation).

a Architectural and maintenance coatings are planned as the subject of  a
  future guideline.
                                      1-2

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although greater numbers of small appliance manufacturers may be located near
large population centers.  Within some industries, large variations in
manufacturing techniques and procedures exist.  Some facilities manufacture
and coat metal parts, then assemble them to form a final product to be sold
directly for retail.  Others, often called "job shops", manufacture and coat
products under contract; specifications differ from product to product.  The
metal parts are then shipped to the final product manufacturer to be assembled
with other parts into some product.  Such facilities are often located in
the vicinity of the manufacturers for whom they perform this service.
     The size of metal coating facilities and their mode of operation varies
not only between industries but also within each  industry.  Two facilities
coating the same product may apply different coatings using completely different
application methods.  The size of the facility is dependent on several things:
number of coating lines, size of parts or products coated, type of coating
operation (i.e., spray,  dip, flow or roll coat),  and number of coats of paint
applied..
     The coatings are a  critical constituent of the metal coating  industry.
In many cases the coatings must provide esthetic  appeal, but in all cases,
they must protect the metal from the atmosphere in which it will be used.
Adverse conditions may  include moisture, sunlight, extreme temperature,
abrasion and corrosive  chemicals.  A wide variety of coatings  are  applied
by the many industries  considered by this document.  Both enamels  (at  about
30-40 volume percent solids) and lacquers  (at 10-20 volume percent solids)
are used, although enamels  are more common.   Coatings are often shipped by
the manufacturer as  a concentrate but  thinned prior to  application.   Typical
coatings are alkyds, acrylics, epoxies, polyesters, vinyls,  silicones,
                                    1-3

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plastisols and phenols.
     Most coatings contain several  (up to 10)  different solvents.   Typical
solvents are ketones, esters, alcohols, aliphatics,  ethers,  aromatics and
terpenes.
1.2  PROCESSES AND EMISSION POINTS
     Each metal coating line tends  to be somewhat unique because of its age,
product coated, design,  and application technique.  Figure 1.1 portrays
common features found in many coating lines, and the following comments
summarize these features.
     Flow diagrams a and b of Figure 1.1 show common methods of applying
coatings on miscellaneous parts and products in both a conveyorized and
batch, oven-baked single coat and two-coat operations.  These methods typically
include spray, xiip, or flow coating for both single coats and primers.
Spray is usually used for the topcoat.
     First the metal substrate is cleansed to remove grease, dust,mill
scale or corrosion.  Often it is pretreated to improve adhesion.  The most
common method  is the five stage cleansing process where the metal is cleaned
with an aqueous caustic solution, rinsed with water, cleaned with a non-
caustic solution, treated with phosphate and finally rinsed again with
water.  Chromate rinses or other pretreatments may also be used.  Other
cleaning methods are also used.  The parts may be cleaned in a shot-blasting
chamber by using organic solvent cleansers. (See Control of Volatile Organic
Emissions from Solvent Metal Cleaning)  The metal often passes through an
oven to remove water before  the coating is  applied.
     Spraying  is the more common method of  applying coatings, for single coat
operations, but flow coating and dipping are also used.  For two coat  operations,
                                      1-4

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the primers are more likely to be applied either by flow or dip coating while
the topcoats are almost always sprayed.
     To apply a flow coating, the metal parts are moved by a conveyor through
an enclosed booth.  Inside, a series of nozzles (which may be stationary or
may oscillate), located at various angles to the conveyor, shoot out streams
of coating which "flow" over the part.  The excess coating drains into a
sink located on the botton of the booth, is filtered and pumped back into a
holding tank for reuse.  Flow coating provides about a 90 percent transfer
efficiency.  Additional solvents are added to control the viscosity due to
evaporation in the flow coater.
     The coated parts are often conveyed through a flashoff tunnel to
evaporate solvent and allow the coating to flow out properly.  The flow
coater and flashoff tunnel are often located in a separate room in the facility
and vented either through roof fans or by means of an exhaust system which
maintains a slight negative pressure to capture the organic vapors.  Exhaust
gas flow is maintained at a rate sufficient to keep organic levels below 25
percent of the lower explosive level or lower if necessary to protect the
employees.
     One or two color single coat applications or primers for two coat
applications may also be applied by dipping.  The metal parts are briefly
immersed either manually or by conveyor into a tank full  of coating.  The
excess coating is allowed to drip from the part and drain back  into the tanks.
This method also provides about 90 percent transfer efficiency  of the coating.
The viscosity in dip coating, as on flow coating is very  critical.  The dip
coating tank and drain board may be completely enclosed in a separate room
and vented through roof fans, or through a ventilation system adjoining the
tank and drain board.  The flow rates from such a ventilation system will
                                   1-6

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depend on the size of the dip tank.
     Spraying is the most common technique for applying single coat,  some
primer and most topcoat applications.  It provides a transfer efficiency of
40 to 70 percent.  Electrostatic spraying with disc, bell and other types
of spray equipment are commonly used to increase the transfer efficiency
to 70 to 90 percent.  Transfer efficiencies will vary with the part being
coated and if manual, the expertise of the operator.  "Touch-up" of assembled
parts is usually performed manually.
     Spray coating is performed in a booth to contain overspray, to minimize
contamination, and sometimes to control the atmosphere in which the coating
is applied.  The spray booths must be maintained at a slight negative pressure
to capture overspray.  Minimum  acceptable air quality for spray booths are
prescribed by OSHA.
     After coating and flashoff, the parts are baked in single or multi-pass
baking ovens at 150-230°C (275-450°F).  Since the cost of reducing organic
emissions in the exhaust stream are proportional to the volume of gas exhausted,
it is important to minimize the infusion of air into the oven.  Several factors,
however, must be considered.  An inlet air velocity of 15 to 45 mpm (50 to
150 fpm) is required to prevent back convection and escape of emissions.
Since the entry and exit openings are usually sized for the largest parts
that may be baked on the line, this may result in greater oven exhaust rates
than needed to meet 25 percent of the LEL.  Dilution air and VOC levels have
a strong effect on air pollution control costs.  For example, halving the air
flow doubles the organic concentration and reduces the capital and operating
cost of add-on control equipment.  Air curtains may be used at the openings
to sweep the openings and minimize the air volume required to contain the
emissions within the oven.
                                     1-7

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     Flow diagram c of Figure 1.1 shows a manual two-coat operation often
used for items such as large industrial, construction, transportation equipment
where the coatings are air or forced air dried.  Ovens cannot be used because
these assembled products include heat sensitive materials (i.e., tires,
rubber tubing, plastic parts, etc.).  Also, these products are often too
large to be cured in an oven.  Other air or forced air dried items include
parts which are too thick or heavy to be cured in an oven and parts where
production dictates that installation of ovens to cure coatings would not be
economically feasible.  For many of these items, the coatings must be resistant
to steam cleaning, the outdoor elements as well as the corrosive coastal salt
environment, and to the hazards of oil, gasoline, chemical spills, fertilizer,
moisture and other miscellaneous exposures.
     The assembled unit is cleaned to remove dirt, grease, or mill scale.
The unit is usually moved to another room where it is spray coated with  a
primer, allowed to dry, spray coated with a topcoat and again allowed to air
or forced air dry.  These rooms which may be often as large as 8 x 8 x ig
meters  (25 x 25 x 60 feet).  A draft fan prevents escape of overspray and
maintains the concentration of organics within the worker safety limits
prescribed by OSHA.  Some of these  items may even be  coated outdoors.
     In summary, organic emissions  from the coating of miscellaneous metal
parts and products are emitted from the application and flashoff areas—and
the ovens (if used).  For spray  and flow coating, the bulk of the  VOC  is
evaporated in the application and flashoff areas  as noted in Table 1.2
                                                                       •
     Figure 1.2 displays the relationship between VOC emissions and  exhaust
flow rate with isopleths of organic concentration in  terms of the  LEL.   It
emphasizes the effect of solvent concentration  on the volume of exhaust gases
                                 1-8

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that must be treated.  Note that if a given coating line evaporates 140
pounds of solvent per hour, the exhaust rate at one percent of the LEL
(80,000 SCFM) is 10 times that of the same stream at 10 percent of the LEL
(8,000 SCFM).  Since operating at higher LEL's clearly reduces the exhaust
stream flow rate, the related capitol and operational costs of VOC emission
control equipment are reduced.
     The flow rates and concentrations are influenced by several factors
including the type of application system and the conditions within the
flashoff area or oven which is the actual source of emissions.  Unfortunately,
flow rates are often designed for the most difficult combination of circum-
stances.  As a result, the rate may be excess of many items coated on a
specific line and as a result, VOC levels are usually well below 25 percent of
the LEL.
                               1-9

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       Table 1.2  SOURCE OF VOC ^MISSIONS FROM COATING MISCELLANEOUS
                        METAL PARTS AND PRODUCTS
                                                 PERCENT  OF  TOTAL  VOC

    Application Method           Application and Flashoff          Oven


    Dip                                   40-50                    50-60

    Flow coat                             50-60                    40-50

    Spray (oven cured)                    70-80                    20-30

    Spray (air dried)                      100                 not applicable
This assumes a coating applied at 25 volume percent solids, 75 percent organic
solvent which is equivalent to a VOC emission factor of 0.66 kg of organic
solvent emitted per liter of coating (5.5 Ibs/gal) minus water.
                                  1-10

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 o
 in

CO
 O
 X

 0)
 i.

 O
 OJ
 S-
 vt
 (O
       0
                           Toluene emitted  (Ibs/hr)
          Figure 1-2.  Data for toluene, LEL = 1.2%  (v/  ),  showing  the
          relationship between VOC emission, exhaust flowrate  and VOC
          concentration.
                                 1-11

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          2.0  APPLICABLE SYSTEMS OF EMISSION REDUCTION


     This chapter discusses coatings low in organic solvents (LOSC) and add-on

equipment for the control of VQC from conventional coating applications

used in the miscellaneous metal part and product industries.
         Table 2-1.  SUMMARY OF APPLICABLE CONTROL TECHNOLOGY
                     FOR MISCELLANEOUS METAL PARTS AND PRODUCTS
     Control Technology


    Water-Borne (spray, dip
       or flow coat)
    Water-Borne
       (electrodeposition)

    Higher-Solids (spray)
    Powder (spray)


    Carbon Adsorption
    Incineration
  Application


Oven baked single coat,
 primer and topcoat;
 air dried primer and
 topcoat

Oven baked single coat
 and primer

Oven baked single coat,
 and topcoat; air dried
 primer and topcoat

Oven baked single coat
 and topcoat

Oven baked single coat,
 primer and topcoat
 application and flash-
 off areas; air dried
 primer and topcoat
 application and drying
 areas

Ovens
Percent Reduction in
 Organic Emissions
            a
       60-90




       90-95a


       50-803



       95-98e


        90b
        90
                                                                 ,+b
    aThese figures reflect only the range in reduction possible.  The actual
    reduction to be achieved will depend on the composition of the coating
    and the replacement low organic solvent coating, transfer efficiency and
    the relative film thicknesses of the two coatings.

     This reduction in VOC emissions is only across the control device and
    does not take into account the capture efficiency.
                                   2-1

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2.1  WATER-BORNE (SPRAY, DIP OR FLOW COAT)
     The application of water-borne coatings  is  similar  to  organic  solvent-
borne coatings thus conversion to water-borne coatings does not  necessarily
require extensive replacement of the existing coating  application equipment.
A reduction of 60 to 90 percent in organic emissions may be achieved by
switching to water-borne coatings.  The actual reduction, however,  will
depend on several variables:  the composition of the original organic
solvent-borne coating, the composition of the water-borne coating replacement,
relative transfer efficiencies, and the relative film thicknesses required.
The transfer efficiency of water-borne coatings is similar to that of
conventional coatings.  Although water is the major carrier, some organic
solvents must be included to temper the evaporation rate, provide the coating
with the desired properties, and provide film coalescence.  Some small
appliance manufacturers have converted their electrostatic spray and dip
coating lines to apply water-bornes.   Water-borne coatings are now being
applied on some farm machinery, on fabricated metal products and commercial
machinery by flow coating, dipping, and both electrostatic and conventional
                 2
spraying methods.
     Further technical details on the use of water-borne coatings may be
found in Volume I, Sections 3.3.1 and 3.3.5.3

2.2  WATER-BORNE (ELECTRODEPOSITION)
     Although converting to electrodeposited water-borne coatings will require
new application equipment (i.e., tank, ultrafilter, rinsing stations, etc.),
it results in increased corrosion protection and can deposit thin coatings
uniformly at greater transfer efficiency  (about 99 percent) than any other
application system.  Electrodeposited coatings may be applied at 0.3 to 1.2 mils
thickness, and film thickness may be adjusted by voltage and immersion time.
                                      2-2

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Farm and commercial machinery, and fabricated metal  product facilities have
been reported to apply coatings by electrodeposition.
     One major advantage of water-borne coatings is  that,  unlike solvent-borne
coatings, the pretreatment dry-off oven may no longer  be required.   After an
additional rinse with deionized water, the parts are subsequently grounded and
immersed into the coating bath which may contain from  8 to 15 volume percent
solids, 2 to 4 volume percent organic solvent, and the balance deionized water.
An electrical potential causes the suspended solids  to migrate and adhere to
the part.  (Coatings are available for application by  either anodic or cathodic
electrodeposition.)  As the coated parts emerge from the bath, the coating is
primarily solids with some water and trace quantities  of organic solvent.  These
solvents control the flow of the coating during the curing process.  The parts are
then rinsed in several stages to remove any excess paint.  (The rinse is then
ultrafiltered to remove the water and organics.  The paint solids are returned
to the bath.)
     A complicating factor in determining the emission factor for electrodeposition
is the very limited information now available on the final disposition of organic
solvent.  If the emission factor considers only the coating applied to the metal
substrate (which would be emitted from the oven^  it is only  about  0.024  to  0.06 kg/liter
(minus water).  This factor does not consider any organic emissions which may occur
from the tank or the rinsing stages.  If the emission factor is based on the bath
composition, it is much greater (i.e., .31 to .38 kg/liter minus water).  This
factor, however, does not consider the effect of solvent recycled to the bath
or purged from the system.  It appears that the methods by which ultrafliter
residue is treated and how the coatings are replenished in the bath vary
considerably from coater to coater.  A conservative emission factor for
electrodeposited coatings is 0.36 kg/liter less water.  Certainly, however, with
                                       2-3

-------
effect of improved transfer efficiency included, use of electrodeposited coatings
can reduce VOC emissions by at least 90 to 95 percent over conventional coatings.
     Electrodeposited coatings are normally baked at 150-200°C (257-400°F).
Research is currently underway to eliminate the intermediate baking step now
used to cure electrodeposited primers prior to topcoat application.
Both the primer and topcoat would be baked as a one-coat system.  This would
provide attendant savings in capital and operating costs and fuel requirements.
     For further technical details on the use of electrodeposition coating
technology, see Volume I, Section 3.3.1.

2.3  HIGHER-SOLIDS COATINGS
     The reduction in volatile organic emissions achievable by converting to
coatings which contain higher solids ranges from 50 to 80 percent.  Coatings with
45 to 60 volume percent solids are currently being applied with spray or roll
coating technology.  Coatings with even greater solids content (60 to 80 volume
percent) are making inroads due to the development of new spray application
technologies.  Research is underway on higher solids coatings which will cure at
ambient temperatures.  These will be very attractive for applications such as
large farm and industrial machinery.
     Higher-solids coatings can be applied by roll coating, or by spraying, either
with automated electrostatic techniques, or manually.  The first two are the
more efficient application methods.  Due to the higher viscosity of high-solids
coatings, additional mechanical, thermal or electrical energy may be necessary
for pumping and adequate atomization.   Transfer efficiencies with high-solids
coatings are often better than with conventional solids coatings particularly
with electrostatic sprays.
     Further technical details on the use of high-solids coatings may be
found in Volume I, Section 3.3.2.8
                                     2-4

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2.4 POWDER COATINGS
     Powder coatings have been sprayed as a single coat on small
appliances, small farm machinery, fabricated metal product parts, and
                                     q
industrial machinery component parts.  Powders can be applied by
electrostatic spraying at thicknesses from 0.9 to 5 mils, and thicknesses
of much less than 1 mil have been achieved on experimental interior
can lines.  Powder coatings are also applied by dipping but the resultant
film is much thicker, a minimum of about 6 mils.  After application
of the coating, the metal part is moved to an oven where the powder
particles melt and flow to form a continuous, solid film.  Powders
are essentially 100 percent solids, but they can release about 0.5 -
3.5 weight percent of volatile organic compounds due to unblocking
and crosslinking reactions during the curing process.
     Powder coatings are applied by electrostatic spray with almost
the same technique used for solvent-borne coatings, although different
equipment must be used.  Film thickness can be controlled by the
voltage potential. Powder coatings wrap around edges of complicated
metal parts and are self-leveling on flat parts, but do not  (as  some
of the liquid counterparts also do not) coat small recesses well.
Depending  on the application, this could be an advantage or  disadvantage.
This problem may be reduced or eliminated by preheating the  parts, but
may result in a thicker film.
     Powder coatings may be applied  in smaller spray booths  than
the ones used for conventional coatings.  As a result, the air  require-
ments necessary for proper ventilation may be greatly  reduced.   Use
of powders may not only conserve space but may also reduce the  energy
*At least  one firm has one year of production experience  applying  a
coating thickness of  1 mil.   Because  thicker films  are more  common,
the cost estimates in  Chapter 3  are  based on  coating thicknesses of
2 mils.
                               2-5

-------
required to heat the spray booth make-up air during the winter months.
     Changing colors when applying powder coatings requires slightly
more time than conventional coatings since any color contamination
does not blend.  If the operator tries to segregate the overspray color
in order to recycle it, the booth and recovery unit should be cleaned
thoroughly to avoid color contamination.  This will require greater downtime.
     Two methods have evolved for minimizing the time required to
change colors.  Some facilities have several overspray recovery
units available that may easily be attached to a single spray booth.
Others have installed several mobile spray booths and associated
recovery equipment   to minimize the number of changeovers that must
be made.  Still another approach has been to use the multicolored
overspray on parts that do not have critical color specifications.
     Although curing temperatures, 170° to 230°C (275-450°F) are often
higher than with conventional coatings, powders do not require a
flashoff zone, the air flow from the ovens may be reduced  since no
solvent is present.  Further technical details on the application of
                                                                    12
powder coatings may be found in Volume I, Sections 3.3.3 and 3.3.5.
2.5 CARBON ADSORPTION
     As discussed  in Chapter 1, at least one-half of the volatile
organic compounds  from coating miscellaneous metal products  is emitted
from the application and flashoff areas.  The remainder  is emitted
from the ovens.  The use of carbon adsorption to collect the emissions
from the application and flashoff areas  can reduce those emissions  by
90 percent across  the  adsorber.
     Carbon adsorption is  considered  a viable control option for  these
                                     2-6

-------
areas although there are no known installations in facilities that coat
miscellaneous metal parts or products.  Carbon adsorption is technically
feasible for these applications   (no new inventions are required for
its implementation), but pilot studies may be necessary before this
control technology is installed.
     The requisite size of a carbon adsorption unit is dependent on
the exhaust flow rate, organic concentration, and the desorption
period.  Design parameters vary with each application because of the
variety of metal parts coated and coatings used.  About 95 percent
efficiency reportedly is effected by dry filters or by water or oil
             14
wash curtains.  Additional particulate removal may be necessary,
however, if the remaining 5 percent is significant enough to render
the bed inefficient.
     Flashoff areas have to be enclosed to maximize capture of the
volatile organic emissions.  The flow rates  and VOC concentrations
depend on the configuration of the coating line and the "tightness"
of the enclosure.  If the coating application areas are located on
the first floor of the plant, for example, and the ovens are mounted
on the roof, it may be difficult and  expensive to try to contain  the
VOC that flashes off as the substrate traverses from the applicator
to the oven. In other cases the  application  areas may be located
near the oven where enclosing the flashoff areas would be  less difficult.
In some situations, the exhaust  system on an oven will draw the  solvent-
laden  air from the flashoff areas into the oven.
     Further technical details on the use of carbon  adsorption may be
found  in Volume I, Section 3.2.1.
                                     2-7

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2.6 INCINERATORS
     Incinerators are the most universally applicable control system
for VOC.  There are no serious technical problems associated with the
use of either catalytic or noncatalytic incinerators on miscellaneous
metal product coating facilities.  Incinerator heat recovery efficiencies
have improved and operating costs have been reduced significantly
in recent years.
     Incineration systems may be more desirable ( less costly and
perhaps more efficient) than adsorption for reducing VOC emissions
from the baking ovens for several reasons:
     1.  No cooling system is required.  High temperature (150  to
230°C) exhaust gases have to be cooled to 40°C or lower before
entering a carbon bed.
     2.  VOC in the exhaust stream can provide appreciable heat energy
eg. 350°C at 25 percent of the LEL.  Thus at significant VOC levels,
auxiliary fuel use can be minimized or sometimes even  eliminated by
the proper use of heat exchangers.
     3.  Particulate and condensible matter from volatilization and/or
degradation of resins, may coat the carbon bed.  These materials will
not affect an incinerator.
     It  is desirable but not always feasible to  incorporate  secondary
heat recovery systems to minimize fuel  consumption  and overall operating
costs.   Waste heat may be recovered for  use in many process  areas;  for
example, cleansing and pretreatment sections, the ovens, and for space
heating  during the colder months.
     Incineration of the exhaust from  application and  flashoff areas
                                   2-8

-------
is certainly technically feasible.  Its economic practicality may
depend on minimizing the volume to be burned and recovering sufficient
heat to keep fuel consumption at an acceptable level.
     Further technical details on the use of incineration may be found
in Volume I, Section 3.2.2.
                                   2-9

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 2.7   REFERENCES

 1    Gallagher, V.  N.,  Environmental  Protection Agency, Research Triangle Park,
     North  Carolina,  Reports  of  trips to  small appliance facilities  in  1976.

 2    Springborn Laboratories, Inc.  (formerly  DeBell  and Richardson,  Inc.), Trip
  '   reports Nos.  18, 21,  69, 135,  142,  143,  and  144.  General  Surface  Coating
     Study  under  contract  by  EPA No.  68-02-2075.

 3.   OAQPS  Guidelines - "Control  of Volatile  Organic Emissions  from  Existing
     Stationary Sources -  Volume I:  Control  Methods for Surface Coating
     Operations,"  EPA-450/2-76-028, November,  1976.

 4.   Springborn Laboratories, Inc., Trip  report No.  22, 87,  135. General
     Surface Coating  Study under contract No.  68-02-2075.

 5.   OAQPS  Guidelines - Volume I, Op. Cit.

 6.   DeVittorio,  J. M., Ransburg Corporation,  Application  Equipment  for High-
     Solids and Plural  Component Coatings, Volume I, No. 2,  April, 1976.

 7.   LeBras, L. R., PPG Industries, Pittsburgh, Pennsylvania, Letter to
     V.  Gallagher in  comment  to  draft of  Volume III, letter  dated
     September 22,  1977.

 8.   OAQPS  Guidelines - Volume I, Op. Cit.

 9.   Springborn Laboratories, Inc., Trip  report No.  48, 88,  95, 98,  122,  123.
     General Surface  Coating  study  under  contract by EPA,  No. 68-02-2075.

10.   Cole,  Gordon E., Jr., Associateon for Finishing  Processes of SME.
     Letter to Vera N.  Gallagher in comment to the draft of  this document,
     letter dated April 18, 1978.

11.   Springborn Laboratories, Op. Cit., reference  9.

12.   OAQPS  Guidelines - Volume I, Op. Cit.

13.   Johnson, W.  J.,  General  Motors Corporation,  Warren, Michigan.   Letter  to
     Radian Corporation commenting  on "Evaluation of a Carbon Adsorption  -
     Incineration Control  System for  Auto Assembly Plants,"  EPA Contract  No.
     68-02-1319,  Task No0  46, January, 1976,  dated March 12, 1976.

14.   Johnson, W.  J.,  General  Motors Corporation,  Warren, Michigan.   Letter  to
     James  McCarthy dated  August 13,  1976.

15.   OAQPS  Guidelines - Volume I, Op. Cit.

16.   Ibid.
                                   2-10

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                          3.0  COST  ANALYSIS
3.1   INTRODUCTION
3.1.1   Purpose
     The purpose of this chapter is  to present capital  and  annualized
costs for alternative ways of controlling solvent emissions at existing
coating lines in the metal coating industry.   A cost-effective analysis
is included as an extension of the cost development.
3.1.2  Scope
     Estimates of capital and annualized costs are presented for con-
trolling volatile organic compounds  (VOC) from application  areas and
curing ovens associated with conveyorized single-coat lines and con-
veyorized two-coat lines.  Control costs for manual two-coat lines are
also estimated; in this process coated parts are air-dried, and only
application area emissions require control.  Flow, dip, and electro-
static-spray coating are application techniques considered  for the
single-coat lines and for the prime coat in two-coat applications.
Electrostatic-spray coating only is considered for the topcoat in two-
coat lines.  The following control alternatives are analyzed for the
three-coat lines:
                                   3-1

-------
Alternative I - Process Modification
     Emissions can be controlled by modifying coating  equipment  to
accommodate one of the following low-solvent coating processes:
     1.   Use of coating with a higher solids (60 percent or  above)
          content
     2.   Use of waterborne coatings
     3.   Powder deposition
     4.   Electrodeposition (EDP)
Alternative II - Exhaust Gas Treatment
     1.   Carbon adsorption
     2.   Thermal incineration (35% and 90% primary heat recovery)
     3.   Catalytic incineration (35% primary heat recovery)
3.1.3  Use of Model Plants
     Cost analyses are presented for three model  sizes of existing
coating lines.  Coating rates analyzed for conveyorized single-coat  and
conveyorized two-coat operations are 139,000 m /yr, 743,000 m /yr, and
           2
1,486,000 m /yr; the rates analyzed for manual two-coat operations
are 418,000 m /yr, 604,000 m2/yr, and 790,000 m2/yr.   The plant  opera-
ting time assumed for each type of application is 2880 hours/yr.
     It must be emphasized that model coating lines used in this analy-
sis are very simple in that they involve a one-color,  single-coat or
two-coat application.  Analyzing multicolor coating systems is beyond
the scope of this analysis.  Also, although control cost estimates  based
on the model plant approach may differ from actual costs incurred,  they
                                   3-2

-------
are nevertheless considered the best means of comparing relative costs
and cost effectiveness of alternative control measures.
3.1.4  Bases for Capital Cost Estimates
     Capital costs represent the investment required for retrofitting a
control system, including costs of equipment, material, labor for in-
stallation, and other associated costs.  Capital  cost estimates are
based on cost surveys of various installations presented in the ref-
erences (1, 2).  Most of the surveyed costs represent new installations.
These costs have been modified to apply to retrofit installations.
     All capital costs are expressed in mid-1977  dollars.  In addition
to basic control equipment, capital costs include auxiliary equipment
such as hoods, ducts, etc., as well as indirect expenses such as con-
tingencies, contractor's fee, and taxes.
3.1.5  Bases for Annualized Costs
     Annualized costs represent the cost of operating and maintaining
the control system and that of recovering the capital investment.
Operating costs include costs for materials, utilities, and normal
maintenance.  Net annualized costs for process changes, i.e., line con-
versions, are incremental costs incurred in converting from high-solvent
to low-solvent coatings.  The bases for these projected incremental
costs are available in the referenced material (1, 2).  Again, it must
be emphasized that these analyses of model coating lines are provided as
a means of comparing the relative costs of alternative control measures.
Various coating industries have devoted considerable resources to the
development of incremental costs of low-solvent coating conversions.
                                  3-3

-------
However, a comparison of these estimates may show a wide variation due
to differences in some key assumptions.   Specifically,  coating material
costs appear to have the greatest impact on annual costs.  Differences
in coating thickness requirements, transfer efficiencies, raw material
costs, and coating specifications will influence these  incremental
costs.
     General cost factors used to estimate annualized costs for model
coating lines are provided in Table 3-1.
3.2.  SOLVENT EMISSION CONTROL IN METAL COATING OPERATIONS
3.2.1  Model Plant Parameters
     Table 3-2 presents technical parameters for the model sizes selec-
ted.  The estimated exhaust flow rates are based on solvent usage in
the operation; and the estimated solvent coatings thickness and trans-
fer efficiencies are based on typical practice.
     Add-on control systems can provide overall emission control effi-
ciencies of the order of 80 to 90 percent.  Separate control systems are
assumed for application/flash-off areas and drying ovens.  Emission
control efficiencies for process modifications range from 70 to 99
percent (3, 4), depending on the type of coating selected.
     The cost analysis is based solely on model sizes.   Generally no
consideration has been given to detailed design characteristics of the
model lines in terms of process equipment requirements,  line speed, etc.
However, it was necessary to consider gas flow rate, required dry coating
thickness, and coating transfer efficiencies to estimate capital and
                                  3-4

-------
     Table 3-1.   COST FACTORS USED  IN  COMPUTING ANNUALIZED COSTS
 I.   Direct  operating costs
     1.   Materials  (as purchased):
         - Conventional prime coating (40% solids)3
         - Alkyd conventional top coating (40%  solids)
         - Solvent  thinner
         - Polyester high solids coating (60% solids)
         - Alkyd waterborne coating (40% solids)3
         - Epoxy powder coating
         - Electrodeposition waterborne (60% solids)
     2.   Utilities
         - Electricity
         - Natural  gas
         - Steam

     3.   Direct labor
     4.   Maintenance labor
         - Process  modifications
         - Add-on systems
     5.   Maintenance Materials
II.   Annualized capital charges
     1.   Depreciation and  interest (process modification)
         - Depreciation and  interest (add-on)
     2.   Taxes, insurance, and administrative overhead

a By volume.
$1.72/1 Her ($6.50/gal)
$2.11/1iter ($8/gal)
$0.28/liter ($1.07/gal)
$3.17/liter ($12/gal)
$2.38/1 Her ($9/gal)
$3.30/kg ($1.50/lb)
$2.91/liter ($11.0/gal)

$0.03/kw-hr
$1.90/60
($2.00/million Btu)
$5.50/thousand Kg
($2.50/thousand Ib)
$10/man-hr

$10/man-hr
0.02 x capital cost
0.02 x capital cost

0.1468 x capital cost
0.1630 x capital cost
0.04 x capital cost
                                          3-5

-------
                                Table 3-2.   TECHNICAL PARAMETERS  FOR MODEL COATING LINES
CO
I
Conveyorized single-coat and two-coat operation
Line size, m2/yr (ftZ/yr)
Exhaust rate, Nm /sec (scfm)
- Flow coat booth
- Flow coat oven
- Dip coat booth
- Dip coat oven
- Spray coat booth
- Spray coat oven
Manual two-coat operation
2 2
Line size, m /yr (ft /yr)
Exhaust rate, Nm /sec (scfm)
- Prime coat booth
- Top coat booth
Process conversion data

- Conventional solvent
- High solids solvents
- Powder deposition
- EDP
- Waterborne solvents
139,000 (1,500,000)

0.20 (420)
0.85 (1800)
0.28 (590)
0.85 (1800)
3.02 (6400)
0.85 (1800)

418,000 (4,500,000)

28.55 (60,500)
28.55 (60,500)

Dry coating thickness, i
25 (1)
30 (1.2)
50 (2)
18 (0.7)
25 (1)
743,000 (8,000,

1.07 (2245)
0.85 (1800)
1.47 (3100)
0.85 (1800)
16.05 (34,000)
0.85 (1800)

604,000 (6,500,

40.78 (86,400)
40.78 (86,400)

»jm (mils)/coat





000) 1,486,000 (16,000,000)

2.15 (4555)
0.85 (1800)
2.97 (6300)
0.90 (1900)
32.10 (68,000)
0.85 (1800)

000) 790,000 (8,500,000)

53.05 (112,400)
53.05 (112,400)

Transfer efficiency, %
80b
80
95
95
80-90b
                      Reference  3.
                      80 percent for spray coating, 90 percent for dip and flow coatings.

-------
operating costs of the control  alternatives considered.   Therefore,  any
changes in these parameters (gas flow rate, dry coating  thickness,  coat-
ing transfer efficiency) will  produce considerable impact on control
costs and cost-effectiveness of different options.
3.2.2  Control Costs
     Table 3-3 through 3-9 present details of control  cost estimates
for seven coating operations.   Tables 3-3, 3-4, and 3-5  present control
costs for the conveyorized single-coat operation; Tables 3-6, 3-7,  and
3-8 for the two-coat conveyorized operation; and Table 3-9 for the
manual two-coat operation.
     Capital costs of converting lines to higher-solids  coatings or to
waterborne coatings are those related to application equipment modifi-
cations only.  Suppliers indicate that conversion to high-solids (60
percent or more solids content) coatings, particularly a high speed
turbine bell or disc high-solids coating, requires installation of new
pumps and fluid transfer equipment.  The cost estimates  include this
equipment (5).  Capital cost estimates change radically for waterborne
coating operations if paint sources are not located close to application
equipment and if stainless steel piping is used for paint recirculation
systems (6).
     Capital costs of converting to a powder coating are associated with
installation of powder application and recovery systems.  Because model
lines are one-color systems, only one recovery system is included in
capital cost estimates.  Some energy, waste disposal, and direct labor
                                  3-7

-------
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-------
         Table  3-4.   INCREMENTAL COSTS  OF  SOLVENT  EMISSION CONTROL OPTIONS FOR CONVEYORIZED SINGLE-COAT OPERATION,
                                                           DIP-COAT  APPLICATION
                                                        (Mid-1977 thousand dollars)
Cost item
° Capital investment
0 Annual costs (credits )d
Material
Electricity
Fuel
Maintenance
Capital charges
0 Total annual ized cost (credit)
0 Solvent emissions controlled,
Mg/yr
0 Emission reduction, %
° Cost effectiveness (credit),
$/Mg of solvent controlled
Applicable control option
Haterborne coatings
source size3
small
12

2
0
0
1
2
5
6
80
833
mediuit
20

11
0
(2)
1
4
14
35
80
400
large
28

22
1
(3)
1
5
26
69
80
377
Electrodeposition (EDP)
source size
small
65

W
2
0
3
12
8
7
90
1143
medium
178

(46)
9
(1)
8
33
3
39
90
77
large
270

(93)
18
(2)
12
50
(15)
78
90
(192)
Carbon adsorption and
thermal Incineration
with 351 primary heat
recovery*1
source size
small
209

0
1
8
9
42
60
7
85
8571
medium
296

0
1
8
13
59
81
37
85
2189
large
357

0
2
9
16
71
98
73
85
1343
Carbon adsorption and
catalytic incineration
with 351 primary heat
recovery0
source size
small
188

0
1
2
9
38
50
7
85
7143
medium
276

0
1
2
13
55
71
37
85
1919
large
337

0
2
2
15
68
87
73
85
1192
Thermal incineration
with 90% primary heat
recovery1
source size
small
64

0
0
5
3
13
21
7
90
3000
medium
126

0
1
10
6
25
42
39
90
1077
large
201

0
1
16
9
40
66
78
90
846
OJ
              See Table 3-2 for source sizes.
              Carbon adsorption on dip-coat booth and incineration with 35 percent primary heat recovery on drying oven.
              Thermal Incineration with 90 percent primary heat recovery on dip-coat booth and drying oven.
              Increments of waste disposal costs, labor costs, and labor overhead are insignificant; these are not included in the annual costs.

-------
          Table 3-5.   INCREMENTAL  COSTS OF SOLVENT EMISSION  CONTROL  OPTIONS  FOR  CONVEYORIZED SINGLE-COAT OPERATION,
                                                           SPRAY-COAT  APPLICATION
                                                        (Mid-1977  thousand dollars)





Cost Hew
* Capital Investment
• Annual costs (credits)
Material
Electricity
Fuel
Maintenance
Capital charges
* Total annuallzed tfost
(credit)
° Solvent emissions con-
trolled, Ng/yr
" Emission reduction, %
° Cost effectiveness
(credit), $/Mg of
solvent controlled
Applicable control option


Waterborne coatings
source size*
small
12

2
0
0
1
2
5


8
80


625
medium
20

9
0
(2)
1
4
12


41
80


293
Urge
28

19
1
(3)
1
5
23


82
80


280


High solids coatings
sourct size
small
30

3
0
0
1
6
10


7
70


1429
medium
43

16
0
(1)
2
8
25


36
70


695
large
59

32
0
(3)
3
11
41


72
70


597


Powder deposition
source size
small
S6

13
0
0
3
10
26


9
90


2889
medium
76

71
0
(2)
3
14
86


46
90


1870
large
101

142
0
(3)
5
19
163


93
90


1753
Carbon adsorption and
thermal Incineration
with 351 primary heat
recovery'1
source size
snail
380

0
2
8
17
76
103


8
79


12875
medium
698

0
9
10
31
140
190


41
79


4634
large
971

0
17
12
44
195
268


81
79


3309
Carbon adsorption and
catalytic Incineration
with 35* primary heat
recovery'1
source size
small
369

0
2
2
16
72
92


8
79


11 500
medium
648

0
9
4
31
136
ISO


41
79


4390
large
957

0
17
6
43
190
256


81
79


3161

Thermal Incineration
with 90S primary heat
recovery1
source size
small
220

0
1
16
10
44
71


8
85


8875
medium
918

0
6
70
41
184
301


44
85


6841
large
1713

0
12
130
77
343
562


88
85


6386
UJ
 I
            See Table 3-2 for source sizes.
            Carbon adsorption on spray-coat  booth and incineration with 35 percent primary heat recovery on drying oven.
            Thermal incineration with 90 percent primary heat recovery on spray-coat booth and drying oven.
            Increments of waste disposal costs, labor costs, and labor overhead are insignificant; these are not Included 1n the annual costs.

-------
Table  3-6.   INCREMENTAL COSTS  OF SOLVENT EMISSION  CONTROL  OPTIONS  FOR  GONVEYORIZED  TWO-COAT OPERATION,
                                        FLOW-  AND  SPRAY-COAT APPLICATION
                                            (Mid-1977 thousand  dollars)
Cost Item
0 Capital Investment
0 Annual costs (credits) d
Material
Electricity
Fuel
Maintenance
Capital charges
0 Total annualized cost (credit)
0 Solvent emissions controlled,
Mg/yr
• Emission reduction, t
• Cost effectiveness (credit),
$/Mg of solvent controlled
Applicable control option
Waterborne coatings
source s zea
small
24

8
0
(1)
1
4
12
14
80
857
medium
40

43
1
(3)
2
7
50
76
80
658
large
56

86
1
(6)
3
10
94
152
80
618
Powder deposition
source s ze
small
56

(4)
0
(1)
3
10
8
16
90
500
medium
76

(21)
(2)
(6)
3
14
(12)
85
90
(141)
large
101

(42)
(3)
(13)
5
19
(34)
171
90
(199)
Carbon adsorption and
thermal Incineration
with 35S primary heat
recovery"
source size
small
580

0
3
16
26
116
161
15
82
10734
medium
974

0
10
18
44
195
267
78
82
3423
large
1299

0
19
20
58
260
357
155
82
2303
Carbon adsorption and
catalytic Incineration
with 351 primary heat
recovery"
source size
small
539

0
3
4
25
108
140
15
82
9333
medium
903

0
10
6
42
187
245
78
82
3141
large
1259

0
19
8
57
252
336
155
82
2167
Thermal incineration
with 90% primary heat
recovery^
source size
small
279

0
2
20
13
56
91
15
87
6067
medium
1002

0
7
78
46
204
335
82
87
4085
large
1869

0
13
149
54
374
590
165
87
3578
 a See Table 3-2 for source sizes.
 b Carbon adsorption on coating booth and incineration with 35 percent primary heat recovery on drying oven.
 c Thermal incineration with 90 percent primary heat recovery on coating booth and drying oven.
 d Increments of waste disposal costs, labor costs, and labor overhead are Insignificant; these are not included In the annual costs.

-------
            Table  3-7.   INCREMENTAL COSTS  OF  SOLVENT  EMISSION  CONTROL  OPTIONS  FOR  CONVEYORIZED TWO-COAT OPERATION,


                                                    DIP- AND  SPRAY-COAT APPLICATION

                                                        (Mid-1977  thousand  dollars)
to
 I
ro
Cost Hem
° Capital Investment
° Annual costs (credits)11
Material
Electricity
Fuel
Maintenance
Capital charges
0 Total annuallzed cost (credit)
° Solvent emissions controlled,
Mg/yr
0 Emission reduction, %
° Cost effectiveness (credit),
$/Mg of solvent controlled
Applicable control option
Waterborne coatings
source size8
small
24

8
0
(1)
1
4
12
14
80
857
medium
40

43
1
(3)
2
7
50
76
80
658
large
56

86
1
(6)
3
10
94
152
80
618
Powder deposition
source size
small
56

(4)
0
(1)
3
10
8
16
90
DOO
medium
76

(21)
(2)
(6)
3
14
(12)
85
90
(141)
large
101

(42)
(3)
(13)
5
19
(34)
171
90
(199)
Carbon adsorption and
thermal incineration
with 35X primary heat
recovery^
source size
small
589

0
3
16
26
118
163
15
82
10867
medium
994

0
10
18
45
199
272
78
82
3487
large
1328

0
19
21
60
266
366
155
82
2361
Carbon adsorption and
catalytic Incineration
with 35* primary heat
recovery"
source size
small
548

0
3
4
25
110
142
15
82
9460
medium
924

0
10
6
43
191
250
78
82
3205
Jarge
1288

0
19
9
58
258
344
155
82
2219
Thermal incineration
with 90* prlnary heat
recovery0
source size
small
285

0
2
21
13
57
93
15
87
6200
medium
1044

0
7
80
47
209
343
82
87
4183
large
1914

0
13
152
86
383
634
165
87
3842
               See Table 3-2 for source sizes.

               Carbon adsorption on coating booth and incineration with 35 percent primary heat recovery on drying oven.

               Thermal incineration with 90 percent primary heat recovery on coating booth and drying oven.

               Increments of waste disposal costs, labor co*ts, and labor overhead are Insignificant; these are not Included In the annual costs.

-------
                  Table 3-8.   COSTS OF SOLVENT  EMISSION  CONTROL OPTIONS FOR CONVEYORIZED  TWO-COAT OPERATION,
                                                          SPRAY-COAT  APPLICATION
                                                        (Mid-1977 thousand  dollars)
Cost item
° Capital investment
0 Annual costs(credits)
Material
Electricity
Fuel
Maintenance
Capital charges
0 Total annualized cost
(credit)
0 Solvent emissions con-
trolled, Mg/yr
° Emission reduction, %
0 Cost effectiveness
(credit), $/Mg of
solvent controlled
Applicable control option
Waterborne coatings
source size3
small
24

8
0
(1)
1
4
12
15
80
800
medium
40

43
1
(3)
2
7
50
82
80
610
large
56

86
1
(6)
3
10
94
165
80
570
High solids solvents
source size
small
60

11
0
0
3
12
26
14
70
1857
medium
86

56
0
(3)
4
16
73
72
70
1014
large
118

112
1
(5)
5
22
135
144
70
938
Powder
deposition process
source size
small
56

(7)
0
(1)
3
10
5
17
90
294
medium
76

(36)
(2)
(6)
3
14
(27)
93
90
(290)
large
101

(71)
(3)
(13)
5
19
(63)
186
90
(339)
Carbon adsorption and
thermal incineration
with 35t primary heat
recoveryb
source size
small
761

0
4
16
34
152
206
15
79
13733
medium
1397

0
17
20
63
279
379
81
79
4679
large
1943

0
34
24
87
389
534
163
79
3276
Carbon adsorption and
catalytic Incineration
"1th 35* primary heat
recovery**
source size
small
720

0
4
4
33
144
185
15
79
12233
medium
1296

0
17
8
61
271
357
81
79
4407
large
1902

0
34
12
86
380
512
163
79
3740
Thermal incineration
with 90i primary heat
recovery0
source size
small
439

0
3
32
20
88
143
16
85
8938
medium
1837

0
12
140
83
367
602
88
85
6841
large
3425

0
23
273
154
685
1135
175
85
6486
CO
 I
           See Table 3-2 for  source sizes.
           Carbon adsorption  on spray-coat booth and incineration with 35 percent primary heat recovery on drying oven.
         c Thermal incineration with 90 percent primary heat recovery on spray-coat booth and drying oven.
           Increments of waste disposal costs, labor costs, and labor overhead are insignificant; these are not Included In the annual costs.

-------
Table  3-9.   COSTS OF  SOLVENT  EMISSION CONTROL OPTIONS  FOR  MANUAL TWO-COAT OPERATION

                                (Mid-1977 thousand dollars)
                                                      Applicable control option
Cost item
° Capital investment
" Annual costs (credits)15
Material
Electricity
Fuel
Maintenance
Capiital charges
° Total annual ized cost (credit)
0 Solvent emissions controlled,
Mg/yr
0 Emission reduction, °i
° Cost effectiveness (credit),
$/Mg of solvent controlled
Waterborne coatings
source size*
small
34

24
0
(2)
2
6
30
12
80
2500
medium
37

35
0
(3)
2
7
41
18
80
2278
large
41

46
1
(3)
2
8
54
24
80
2250
High solids coatings
source s ze
small
72

50
0
(1)
3
14
66
10
70
6600
medium
78

66
0
(2)
4
15
83
15
70
5533
large
86

91
0
(3)
4
16
108
20
70
5400
Carbon adsorption
source size
small
1740

0
15
4
78
174
232
13
80
17841
medium
2226

0
21
5
100
223
299
18
80
16611
large
2596

0
27
7
117
260
353
24
80
14708
Thermal Incineration
with 90t primary heat
recovery
source size
small
1619

0
5
59
73
162
262
13
85
20154
medium
2216

0
7
85
100
222
364
19
85
19158
large
2758

0
10
110
124
276
458
25
85
18320
  See Table3-2  for source sizes.

  Increments of waste disposal costs, labor costs,  and labor overheads are  insignificant; these are not included in the annual
  costs.

-------
savings are estimated for powder coating  conversions  (1,  2);  however,  a
higher coating thickness of 50 um (2 mils)  assumed  for powder coating
diminishes possible savings.
     For electrodeposition, lower applied film thickness  helps override
some of the associated increased electrical costs (1).
     Annualized costs of incineration of  oven emissions primarily
represent fuel required to raise the temperature of the exhaust gases
from 160°C (320°F) to 760°C (1400°F).
3.3  COST EFFECTIVENESS
     Figures 3-1 through 3-7 present cost-effectiveness curves for the
options analyzed:  Figures 3-1, 3-2, and  3-3 for conveyorized single-
coat operation; Figures 3-4, 3-5, and 3-6 for conveyorized two-coat
operation; and Figure 3-7 for manual two-coat operation.   These curves
represent the effect of line size on the  cost per unit weight of solvent
controlled.  The cost per unit weight of  solvent controlled decreases
with the increasing line size in all cases.
     The two most cost-effective options  evaluated for conveyorized
single flow-coat and single dip-coat operations appear to be conversion
to waterborne coatings and conversion to  the electrodeposition process.
The most costly options appear to be add-on control devices.  Conversion
to waterborne coatings seems to be a cost-effective option for spray
coating in a conveyorized single-coat operation; carbon adsorption
combined with thermal incineration with 35 percent primary heat recovery
is the most costly.
                                   3-15

-------
   10,000
S   8000 h
o
     6000
o   4000
en
p    2000
*•••*
o
LLJ
tt
CJ
o
o
    (2000)
                 • WATERBORNE COATINGS
                 O ELECTRODEPOSITION  (EDP)
                 A CARBON ADSORPTION AND THERMAL  INCINERATION
                         WITH 30% PRIMARY  HEAT  RECOVERY
                 A CARBON ADSORPTION AND CATALYTIC  INCINERATION
                          WITH 30%  PRIMARY HEAT RECOVERY
                 * THERMAL INCINERATION WITH 90%
                	PRIMARY HEAT RECOVERY	
                          5              10

                          COATING RATE, TO5 m2/year
15
      FIGURE 3-1.   Cost-Effectiveness Comparison of Solvent
                   Emission Control Options

               Conveyorized Single-Coat Operation
                     Flow-Coat Application
                              3-16

-------
                ^WATERBORNE COATINGS
                O ELECTRODEPOSITION  (EDP)
                & CARBON ADSORPTION AND THERMAL INCINERATION
                        WITH 30% PRIMARY HEAT RECOVERY
                * CARBON ADSORPTION AND CATALYTIC INCINERATION
                         WITH 30% PRIMARY HEAT RECOVERY
                W THERMAL INCINERATION WITH 90%
                    PRIMARY HEAT RECOVERY
   10,000
     8000
o
CC
H-

O
o
to
o
     6000
     4000
§   2000
UJ
QC
<"
o      0
o
   (2000)
         0
5              10

 COATING RATE,  ID5 m2/year
15
       FIGURE 3-2.   Cost-Effectiveness  Comparison of Solvent
                    Emission Control  Options

                Conveyorized Single-Coat Operation
                       Dip-Coat Application
                             3-17

-------
   18,000
   15,000
s
£ 12,000
UJ
>
o

o   9000

«v.
•*%
 *

£   6000
en
CJ
to
     3000
                   WATERBORNE COATINGS
                   CARBON ADSORPTION AND THERMAL INCINERATION
                         WITH 302 PRIMARY HEAT RECOVERY
                   CARBON ADSORPTION AND CATALYTIC INCINERATION
                          WITH 30% PRIMARY HEAT RECOVERY
                   THERMAL INCINERATION WITH 90%
                     PRIMARY HEAT RECOVERY
                   POWDER DEPOSITION
                   HIGH SOLIDS COATINGS
                                                        I
                         5              10
                         COATING RATE, 105 m2/year
15
        FIGURE  3-3.  Cost-Effectiveness Comparison of Solvent
                    Emission Control Options

                Conveyorized Single-Coat Operation
                      Spray-Coat Application
                              3-18

-------
o
o
o
to
15,000



12,000




  9000




  6000
     3000
o
o
    (3000)
                 • WATERBORNE  COATINGS
                 A CARBON  ADSORPTION AND  THERMAL  INCINERATION
                         WITH  30%  PRIMARY HEAT  RECOVERY
                 A CARBON  ADSORPTION AND  CATALYTIC  INCINERATION
                           WITH 30% PRIMARY HEAT RECOVERY
                 * THERMAL INCINERATION WITH  90%
                      PRIMARY HEAT  RECOVERY
                 S? POWDER  DEPOSITION
                                                        \
                         5              10

                         COATING RATE, 105 m2/year
                                                    15
        FIGURE 3-4.  Cost-Effectiveness Comparison of Solvent
                     Emission Control Options

                  Conveyorized Two-Coat Operation
                 Flow- and Spray-Coat Application
                                3-19

-------
                    WATERBORNE  COATINGS
                    CARBON  ADSORPTION  AND  THERMAL  INCINERATION
                         WITH  30%  PRIMARY HEAT  RECOVERY
                    CARBON  ADSORPTION  AND  CATALYTIC  INCINERATION
                           WITH 30% PRIMARY HEAT RECOVERY
                    THERMAL INCINERATION WITH 90%
                      PRIMARY HEAT  RECOVERY
                    POWDER  DEPOSITION
CJ
   15,000
   12,000
     9000
o
en
vo
o
o
     6000
     3000
    (3000)
          0
5              10

COATING RATE, 105 m2/year
15
        FIGURE 3-5.  Cost-Effectiveness Comparison of Solvent
                     Emission Control  Options
                   Conveyorized Two-Coat Operation
                  Dip- and Spray-Coat  Application
                                3-20

-------
                  «^WATERBQRNE COATINGS
                  A CARBON ADSORPTION AND THERMAL INCINERATION
                          WITH 30% PRIMARY HEAT RECOVERY
                  A CARBON ADSORPTION AND CATALYTIC INCINERATION
                           WITH 30% PRIMARY HEAT RECOVERY
                  V THERMAL INCINERATION WITH 90%
                      PRIMARY HEAT RECOVERY
                  S7 POWDER DEPOSITION
                  • HIGH SOLIDS COATINGS
o
at
    15,000
    12,000
      9000
O
01
o
o
      6000
      3000
    (3000)
                                                         I
                                                        JQL-
                          5              10

                          COATING RATE,  105 m2/year
15
          FIGURE 3-6.  Cost-Effectiveness Comparison of Solvent
                       Emission Control  Options

                     Conveyorized Two-Coat Operation
                         Spray-Coat Application
                                3-21

-------
p

I—
z
V)
U-
o
o
   24,000
   20,000
   16,000
   12,000
     8000
     4000
                     WATERBORNE COATINGS
                     CARBON ADSORPTION AND THERMAL INCINERATION
                           WITH 30% PRIMARY HEAT RECOVERY
                     THERMAL INCINERATION WITH 90%
                       PRIMARY HEAT RECOVERY
                     HISH SOLIDS COATINGS
I
                                                        10
                          COATING RATE, 105 m2/year
         FIGURE 3-7.   Cost-Effectiveness  Comparison  of Solvent
                      Emission  Control  Options

                       Manual Two-Coat  Operation

                                 3-22

-------
     Conversion to a powder-coating  process  is  the  most  cost-effec-
tive control option evaluated for conveyorized  two-coat  operations.
Add-on control systems appear to be  considerably more expensive than
process modification options.
     Conversion to waterborne coatings is the least costly option
evaluated for manual two-coat operations.  Again, add-on control systems
cost much more than process changes.
     In flow and dip coating in conveyorized single-coat operations,
thermal incineration with 90 percent primary heat recovery* appears to
be a more cost-effective add-on control than carbon adsorption with
either thermal or catalytic incineration-! with 30 percent primary heat
recovery.  This system also appears to be the most cost-effective for
small size lines only in all other operations  (spray-coating in con-
veyorized single-coat operations and all coatings  in conveyorized two-
coat operations); however, it is the least cost-effective for medium
size and large size lines.  For these applications, carbon adsorption
with thermal  incineration at 30 percent primary  heat recovery seems to
be more cost-effective than carbon adsorption with catalytic incinera-
tion at 30 percent primary heat recovery.
     The carbon adsorption system appears to be  more cost-effective than
thermal incineration, with 90 percent primary  heat recovery on manual
two-coat operations.
* Thermal incineration with 90 percent primary  heat recovery  is applied
  on coating booth and drying oven.
t Carbon adsorption on booth and thermal/catalytic incineration on drying
  oven.
                                 3-23

-------
 3.4  SUMMARY
     Cost analyses of the model lines indicate that modification of the
coating process to a low-solvent coating usually appears to be more
cost-effective for control of VOC than add-on control.   However, because
annualized costs for alternative coating systems are greatly affected by
assumptions implicit in the calculation of coating costs, comparisons
between alternative coating systems can exhibit significant case by case
variations.
                                   3-24

-------
3.5  REFERENCES

 1.  Second Interim Report on Air Pollution Control  Engineering and Cost
     Study of the General  Surface Coating Industry.   Prepared by Spring-
     born Laboratories, Inc., under EPA Contract No.  68-02-2075.  August
     23, 1977.

 2.  Second Interim Report on Air Pollution Control  Engineering and Cost
     Study of the General  Surface Coating Industry - Appendixes A & B.
     Prepared by Springborn Laboratories, Inc., under EPA Contract No.
     68-02-2075.  August 23, 1977.

 3.  Study of Systems for Heat Recovery from Afterburners.  Industrial
     Gas Cleaning Institute, Stamford, Connecticut.   EPA Contract No.
     68-02-1473, Task No,  23.  October 1977.

 4.  REECo Newsletters 1 through 4.  REECo Regenerative Environmental
     Equipment Co., Inc.,  Muncy, Pennsylvania.  1973.

 5.  Information supplied to U.S. EPA by Regenerative Environmental
     Equipment Co., Inc. (REECo),  March 31, 1978.

 6.  High Solids Coatings Volume 2, No. 2.  Technology Marketing Corpora-
     tion, Stamford, Connecticut.  April 1977.


3.6  BIBLIOGRAPHY

     Control of Volatile Organic Emissions from Existing Stationary
     Sources, Volume I:  Control Methods for Surface-Coating Operations.
     EPA-450/2-76-Q28, Research Triangle Park, North Carolina.  November
     1976 (OAQPS No. 1.2-067).

     Control of Volatile Organic Emissions from Existing Stationary
     Sources, Volume II:  Surface Coating of Cans, Coils, Paper, Fab-
     rics, Automobiles, and Light-Duty Trucks.  EPA-450/2-77-008,
     Research Triangle Park, North Carolina.  May 1977  (OAQPS No. 1.2-073),

     Report of Fuel Requirements, Capital Cost and Operating Expense  for
     Catalytic and Thermal Afterburners.  CE Air Preheater,  Industrial
     Gas Cleaning Institute, Stamford, Connecticut.  EPA-450/3-76-031.
     September 1976.

     Capital and Operating Costs of Selected Air Pollution Control
     Systems.  SARD, Inc., Niles,  Illinois.  EPA Contract No. 68-02-
     2072.  May 1976.
                                   3-25

-------
         4.0  DETERMINATION  OF  APPLICABLE  EMISSION  LIMITATIONS
      This chapter shows how an agency may use  the  logic  diagram  presented
 as Figure 4.1 to develop a  standard  appropriate  for almost  any coating
 process which applies surface  coatings on a metal  substrate.
      The procedure for determining emission limits which represent
 the presumptive norm achievable by various processes.   It requires  some
 knowledge of the industry,  the coating process and the requirements
 demanded of the coating. The  procedure is to  start at the  top of
 Figure 4.1 and at each decision node (Indicated  by a circle)  choose
 the appropriate option.  Until reaching a block  that presents  the
 level of control that is presumed to be achievable through  the application
 of RACT by the manufacturer.
      As an example, to find the recommended emission limit  for a
 continuous operation that coats phosphate treated  machine brackets  with
 a black oven cured dipcoat  at  0.7 mils film thickness, the  procedure
 is as follows:
      '  Beginning at the top,  proceed to node B.
      '  The item is not clear-coated, does not contain any heat sensitive
         materials and is baked in an oven when coated, so proceed to node C.
      11  The brackets are marketed in one color,  so proceed  to node  D.
         Because powder coatings are  not applicable in this  case, the
         recommended emission limit for this process is 0.36 kg/liter
         (3.0 Ibs/gal) minus water.
      This would then be the level of control presumed to represent RACT
for this process.  It may be achieved through the use of either water-
borne dip or electrodeposited water-borne coatings.  Higher solids and
powder coatings can also be used but may result in thicker films than

                                4-1

-------
the 0.7 mil obtained from low solids coatings.
     Current technology does not provide low-polluting coatings which
can successfully replace conventional coatings for all the specialty
items coated by the many industrial categories covered by these
emission limits.  Some low-polluting coatings are being used on production
lines while others are in various stages of research.  There will be,
however, situtations where low-polluting coatings may never be applicable
and even the use of add-on control technology may not be feasible
either technically or economically.
                                4-2

-------
                        Manufacture of Metal  Parts and Products
Air or forced air-dried items:
Parts too large or too heavy for
practical size ovens and/or sensi-
tive heat requirements.  Parts to
which heat sensitive materials are
attached.  Equipment assembled
prior to too coating for specific
performance or quality standards.
0.42 kg/liter (3.5 Ibs/gal) (5)
   No or infrequent color chance,
   or small number of colors
   applied.
                      Clear Coat
         0.52  kg/liter
         (4.3  Ibs/gal)
                                               (6)
    owder
   J.05 kg/liter
   P. 4  Ibs/gal)
Outdoor or harsh
exposure or extreme
performance
characteristics ,c>
0.42 kg/liter   (i>'
(3.5 Ibs/gal)
Frequent color chanqe and/
or large number of colors
applied, or first coat on
untreated ferrous substrate
0.36 kg/liter
(3.0 Ibs/qal)   (7)
                        Figure 4.1   Logic diagram for derivation of emission
                        limits for  coatina of miscellaneous metal parts and
                        products.
                                     4-3

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4.1  REFERENCES

1.  The recommended emission limitations for this category are given in
    "Control of Volatile Organic Emissions from Existing Stationary
    Sources - Volume II:  Surface Coating of Cans, Coils, Paper, Fabric,
    Automobiles and Light Duty Trucks,"  EPA-450/2-77-008, May, 1977.

2.  The recommended emission limitations for this category are given in
    "Control of Volatile Organic Emissions from Existing Stationary Sources -
    Volume III Surface Coating of Metal Furniture," EPA-450/2-77-032,
    December, 1977.

3.  The recommended emission limitations for this category are given in
    "Control of Volatile Organic Emissions from Existing Stationary
    Sources - Volume IV:  Surface Coating for Insulation of Magnet
    Wire," EPA-450/2-77-033, December, 1977.

4.  The recommended emission limitations for this category are given in
    "Control of Volatile Organic Emissions from Existing Stationary
    Sources - Volume V:  Surface Coating of Large Appliances," EPA-450/
    2-77-034, December, 1977.

5.  This  emission limit is achievable by use of  about  52 volume percent solids
    organic solvent-borne coating.  Units for this and other limitations
    are kilograms of solvent emitted per liter of coating applied (minus
    water).

6.  This limit is achievable by use of a 41 volume percent solids organic
    solvent-borne or a water-borne equivalent coating.


7.  This emission limit is acheivable by use of a 59 volume percent higher
    solids or a water-borne equivalent coating, or powder or electrodeposited
    water-borne coatings.  DuPont Comments to the First Draft of Control of
    Volatile Organic Emissions from Existing Stationary Sources - Volume VI:
    Surface Coating of Miscellaneous Metal Parts and Products, Letter Dated
    April 20, 1978.

8.  There are some products for which a coating thickness greater than 2 mils
    is required out other coating quality or performance requirements preclude
    the use of powder coatings.  Comments from Deere and Company on the First
    Draft of Control of Volatile Organic Emissions from Existing Stationary
    Sources - Volume VI: Surface Coating of Miscellaneous Metal Parts and
    Products, Letter dated March 29, 1978.
                                   4-4

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           5.0  ADVERSE AND BENEFICIAL EFFECTS OF APPLYING TECHNOLOGY

     This chapter reviews  the adverse and beneficial effects of each technique
which reduces VOC emissions.  This includes not only environmental aspects but
also energy and cost.  It also highlights any limitations of low  organic
solvent technology as compared to conventional high organic solvent coatings.
5.1  WATER-BORNE  (SPRAY, DIP, OR FLOW COAT)
     There are several advantages to converting to water-borne coatings.
     "  Conversion to water-borne coatings will likely be the first option
considered by many facilities because of the possibility that these
coatings can be applied with minimal modification of existing equipment.
     *  Converting to water-borne coatings provides a potential decrease
in toxicity and flammability.
     "  Water-borne coatings may be thinned with water.
     "  Coating equipment can be cleaned or flushed with water rather
than organic solvent.  (If water-borne coatings are allowed to dry, however,
they are then no longer soluble in water and must be cleaned with solvent.
     '  Use of water-borne coatings may allow a decrease in oven temperature.
     "  Use of water-borne coatings will permit some reduction in air flow
since the amount of organics which must be evaporated in the oven is
reduced.   (The permissible reduction may be limited, however, by high humidity
within the oven which will result in condensation on the oven walls and possibly
cause improper curing of the film.
        In some cases the dry-off oven may no longer be necessary.^
     There are some potential disadvantages to water-borne coatings when compared
with conventional organic-borne coatings.
                                     5-1

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     •  Spraying with water-borne coatings may require closer attention
to detail than with organic-borne coatings because temperature, humidity,
gun-to-metal-part distance, and flashoff time may affect the appearance
and performance of the coating.
     '  On many large electrostatic spray lines, use of water-borne coatings
may be impractical because of the difficulties involved in electrically
insulatina the entire system.
     '  Water-borne coatings applied by dip and flow coating application
equipment will need to be monitored more closely due to their more sensitive
chemistry.
     "  An additional rinse may be needed.  Cleansing and pretreatment of the
substrate are more critical because of possible coating contamination and pH
                                            3
changes within the dip or flow coating tank.
     "  Some equipment may have to be replaced or adjusted (due to different
surface tension of water than that of organic solvent) or protected from
corrosion.   (In one converted flow coating operation, the only change was
that the number of nozzles had to be doubled to obtain the same coverage as
                            c
with conventional coatings.)
     " The coating bath, flashoff time, temperature, air circulation, and
humidity may have to be controlled and frequently monitored, because changes
in weather conditions may affect the application of water-borne coatings.

5.2  ELECTRODEPOSITION
     Several other advantages, in addition to reduced VOC emissions, accrue
from converting to electrodeposition.
     '  The major one is improved quality control, a consequence of the fully
automated process.
                                  5-2

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        It provides excellent and uniform coating coverage and corrosion
protection because the paint particles are able to get into small recesses
of parts.
     "  Fire hazards and potential toxicity are decreased in electrodeposition
due to the minimal organic solvent content.
        If electrodeposition replaced a spray coating operation, the solid
and liquid wastes associated with spraying operations will be reduced
drastically.
     *  The lower organic content permits lower ventilation rates, resulting
in reduced energy consumption.
     There are some disadvantages to the electrodeposition process.
     "  Electrodeposition may increase electrical consumption.  The anaount
will depend on the original application system, the size of the electro-
deposition bath, and the thickness of the coating applied.  Electrical energy
is required for the coating system, the refrigeration to overcome the
temperature rise from the electrical process, for good paint circulation
in the bath, and to operate the ultrafilter.  Electrodeposition may consume
three times as much energy  in the application area as water-borne flow or dip
coating operations.   It does not, however, appear as energy inefficient
when compared to a spraying operation because the high air volumes are no
longer required.  Energy consumption will  also be less in the  baking process.
The air flow in the oven may be reduced and the flashoff  tunnel  may be
omitted.
      '  A poor electrical connection will  result  in  a poor coating  (for
example, if the hooks which hold  the metal parts  are not  properly  cleaned or
hung and inadvertently  provide an electrical insulation, the quality of the
coating will suffer.)
                                5-3

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     "   The coverage is so uniform that electrodeposited coatings will  not
hide imperfections in the substrate.
     "   Conversion to electrodeposition will  require a change of equipment
at significant capital cost and can be relatively expensive on small
scale production lines.
5.3  HIGHER SOLIDS COATINGS
     One of the greatest advantages of converting to higher solids coatings
as a means of reducing emissions of VOC is that they may be applied with
little change to existing equipment.   Some application equipment (i.e.,
spray guns) may have to be replaced or a paint heater may have to be
installed to reduce the viscosity of the higher solids coatings but these
are relatively inexpensive changes.  Conversion to high solids coatings can
reduce a plant's energy consumption.   Air flow in the spray booth can be
decreased because less organic solvent must be evaporated from a high solids
coating when applying the same volume of coating.  Since the energy required
by the oven is largely dependent on the air flow (and it, in turn, is
heavily influenced by the organic concentration limitations imposed for
               Q
safety reasons) , the use of higher solids coatings will reduce energy
requirements.  Solid and liquid wastes may also decrease since less coating
is applied per dry mil.  However, the tackiness of high solid coatings may
                            g
make cleanup more difficult.
     Some two-component high solids coatings may contain isocyanate compounds
which are potentially toxic and must be handled and applied with caution.
These also require installation of special application equipment.
5.4  POWDER COATINGS
     There are several advantages obtained after a facility is converted  to
powder coatings.
                                   5-4

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     *  VOC emissions are almost completely eliminated.
     •  There are no solid or liquid wastes to be disposed of as compared
to solvent-borne coatings.
     '  Powder does not require the purchase, or use of  solvents to
control the viscosity of the coating or to clean the equipment.
     '  Powders can mask imperfections and weld marks.
     *  Conversion to powder coatings may reduce the energy requirements
in a spray booth because the large volumes of fresh air  required for
application of solvent-borne coatings may not be required.  Energy require-
ments for the ovens may also be reduced because little organics are being
evaporated requiring less dilution.  (It has been estimated that a 35-70
percent overall reduction in energy requirements will result when a conven-
tional single coat spray application is replaced with powder and 55-70
percent reduction will occur for a two-coat spray application.)
     "  The exhaust air from the spray booth can be filtered and returned
to the working area.
     "  Up to 98 percent transfer efficiency of powder coatings can be
realized since the overspray can be reclaimed.  Not all  overspray is always
reusable, however, because a buildup of powder fines may have  to be discarded,
and the larger and heavier granules may have to be reprocessed  again before
they are suitable for reuse.
     There are several disadvantages to converting to the use  of powder
coatings.
     "  The conversion is non-reversible since all application  equipment,
spray booths, and associated equipment (and often ovens) used  for liquid
systems must be replaced.  This will then  limit the flexibility of the
facility to apply other coatings.
                                  5-5

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     "  Coating film thicknesses of less than 0.9 mils have not been
successfully obtained with powders on a production line basis.
     '  Metallic powder coatings are not as esthetically pleasing as con-
ventional metallics.
     "  Color matching of a powder coating is difficult because its color
cannot be changed by the applicator.  Solvent borne coatings can be.
     "  Powder films have appearance limitations for some applications.
     "  Uncured powder coatings must be kept dry since their subsequent
performance can be affected.
     '  Powder coatings are subject to explosions (as are many particulate
dusts).12
     "  Color changes for powder require about half an hour downtime if
powder is recovered for reuse.  This may greatly curtail production
capacities.  Color changes may be shortened if powders are not reclaimed
in their respective colors, but this results in a coating usage efficiency
of only 50 to 60 percent.

5.5  CARBON ADSORPTION
     Although the technology is well documented and considered technically
feasible, there are not miscellaneous metal part or product facilities
known to be using carbon adsorption systems to reduce organic emissions
from coating application of flashoff areas.  The energy required to operate
a carbon adsorption system is a potential disadvantage.  The actual quantity
will depend on the size of adsorber(s) and the concentration of the solvents
entering the carbon bed.  Any reduction which can be made in the amount of
air flow from the coating application and flashoff areas will  permit
purchase of a smaller adsorber with an  attendant reduction in energy requirements.
                                    5-6

-------
     The amount of solid and liquid waste generated by the use of a carbon
adsorber will depend on the type of coating application system.  For
example, emissions from flow and dip coating operations do not require
filtration or scrubbing.  Emissions from spray booths, however, may require
pretreatment by filtration or scrubbing since the overspray may foul the
adsorber bed.  Water miscible solvents may produce a water pollution problem
if the adsorber is regenerated with steam.  This, however, can be avoided by
incinerating the regeneration stream, by stripping the organics from the
condensate or using nitrogen gas as a stripping medium.  Each will increase
the cost and energy consumption of a carbon adsorption unit.  Since there
is little possibility that the recovered solvents may be reused in the
miscellaneous metal part and product industries, any recovery or solvents
would be for fuel value only.
     An important factor when considering installation  of a carbon adsorption
system is plant space.  Large facilities may require many dual-bed carbon
adsorption units in parallel which will need a relatively large area within
the plant.

5.6  INCINERATION
     The most common and widely applicable technique for the reduction of
organic emissions is incineration.  Incinerators  (or afterburners) have
been used for many years for reducing organic emissions.  One disadvantage
is the quantity of additional fuel required unless heat recovery is used.
The use of primary heat recovery to preheat the inlet gas stream to near
incineration temperature will minimize and can even eliminate fuel require-
ments.  If secondary heat recovery can be used for other energy-using
processes, fuel requirements can be reduced even further.   If there are
enough areas where secondary heat may be utilized, an incineration system
                                  5-7

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may even reduce the plant's overall fuel consumption.  Table 5-1 shows the
potential decreases in energy usage when using incinerators followed by
tube and shell heat exchangers with heat recovery efficiencies of 38 percent
to 55 percent.  Some examples where secondary heat from the incinerator
exhaust may be used are: oven makeup air, boiler, cleaning processes, dryoff
ovens, and plant room heating.  Greater primary heat recovery efficiencies
(80 to 95 percent) are shown in Table 5-2 using other types of heat exchangers
such as ceramic wheel stone packed beds.  These are reportedly very attractive
even for low organic concentration streams because of their low fuel requirements.
                                     5-8

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                                   TABLE  5-1

                      BURNER REQUIREMENTS FOR  INCINERATORS

                               IN 106 BTU/HRa'b'13


NON-CATALYTIC INCINERATORS               5 percent  LEL           15 percent LEL

   No Heat Recovery
         5000 scfm                             5.82                     4.05
       15,000 scfm                            17.48                    12.16
       30,000 scfm                            34.95                    24.31

38% Efficient Primary Heat Recovery

         5000 scfm                             3.32                     1.56
       15,000 scfm                            10.09                     4.73
       30,000 scfm                            19.97                     9.38

Primary and 55% Efficient Secondary
  Heat Recovery

         5000 scfm                             1.42                    -0.34
       15,000 scfm                             4.40                    -0.66
       30,000 scfm                             8.67                    -1.82

CATALYTIC INCINERATORS

   No Heat Recovery
         5000 scfm                             1.69                     1.69
       15,000 scfm                             5.07                     5.07
       30,000 scfm                            10.14                    10.14

38% Efficient Primary Heat Recovery

         5000 scfm                             0,79                     0.26
       15,000 scfm                             2.38                     0.77
       30,000 scfm                             4.76                     1.54

Primary and 55% Efficient Secondary
  Heat Recovery

         5000 scfm                            -0.21                     -1.07
       15,000 scfm                            -0.62                     -3.22
       30,000 scfm                            -1.24                     -6.46

a)  Based on 300°F oven outlet temperature; 1400°F outlet temperature for non-catalytic
    and 600°F inlet temperature for catalytic incinerators.

b)  (-) indicates net overall fuel savings.

c)  These heat  recovery  efficiencies are based on sensible heat,


                                      5-9

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                                TABLE 5-2

          BURNER REQUIREMENTS FOR NONCATALYTIC INCINERATORS

              WITH STONE PACKED BED HEAT EXCHANGERS

                       in 106 BTU/HRa'b'c>14
85% EFFICIENCY PRIMARYHEAT RECOVERY^

              5,000 scfm
             15,000 scfm
             30,000 scfm
5 percent LEL      15 percent LEI
    0.29
    0.87
    1.75
   - 0.91
   - 2.73
   - 5.45
90% EFFICIENCY PRIMARY HEAT RECOVERY

              5,000 scfm
             15,000 scfm
             30,000 scfm
5percent LEL

  - 0.01
  - 0.02
  - 0.04
15 percent LEL

   - 1.21
   - 3.62
   - 7.24
 ' These heat recovery efficiencies include sensible heat and the heat of
combustion of the VOC.

b' Energy value of VOC used is 1.2 MM/BTU/HR per 10,000 scfm.

 ' {-) indicates overall fuel savings
                                   5-10

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 5.7   REFERENCES

 1.   McCormick, Donald,  "Converting a  Flowcoater to Water-Borne Paint,"
     Whirlpool Corporation.   Presented at the NPCA Chemical Coatings
     Conference,  Cincinnati,  Ohio, April 23, 1976.

 2.   Ibid.

 3.   Water-Borne  Flow coating and Dip, Products Finishing, pages 73-76,
     February, 1977.

 4.   Products  Finishing,  Op.  Cit.

 5.   McCormick, Op,  Cit.

 6.   Products  Finishing,  Op.  Cit.

 7.   Kennedy,  W.  D.,  "Major Appliance  Electrocoat," Whirlpool  Corporation.
     Presented at the NPCA Chemical Coatings Conference,  Cincinnati,  Ohio,
     April  22, 1976.

 8.   DeVittorio,  J.  M.,  Ransburg Corporation,  "Application Equipment  for
     High-Solids  and Plural Component  Coatings," Volume I, No. 2,  April, 1976.

 9.   "Question Corner,"  High-Solids Coatings,  Volume  I, No.  3, July,  1976.

10.   "Economic Justification of Powder Coating," Powder Finishing World,
     pages  18-22, 4th Quarter, 1976.

11.   LeBras, Louis,  Technical Director,  PPG Industries, Inc.,  Pittsburgh,
     Pennsylvania.  Letter to V. N. Gallagher  in comment of the metal furniture
     draft document.   Letter dated August 31,  1977.

12.   Ibid.

13.   Combustion  Engineering Air Preheater,  Wellsvilie. New York.   Report of
     Fuel Requirements,  Capital Cost,  and Operating Expenses for Catalytic
     and Thermal  Afterburners, EPA Contract Report No. EPA-450/3-76-031,
     September,  1976.

14.  Mueller, James H.,  Regenerative  Environmental  Equipment Co.,  Inc., Morris
     Plains, New Jersey.  Letter to V. N.  Gallagher in comment of this draft
     document.  Letter dated March 31, 1978.
                                     5-11

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           6.0  MONITORING TECHNIQUES AND ENFORCEMENT ASPECTS

     This chapter discusses the recommended emission limits, the monitoring
techniques and enforcement aspects for both coatings which are low in organic
solvents and add-on control equipment.
      Limitations in VOC may be expressed in terms of mass or volume and
may be based on the entire coating (including organic solvent) or only on
paint solids.  In this guideline, limitations are expressed as the allow-
able mass of organic solvent per unit volume of coating (kgs per liter of
coating or Ibs per gallon of coating - minus water) as it  is delivered to the coating
applicator.  The water content of the coating is not included in the ratio.
The principal advantage of this format is that enforcement is relatively
simple.  Field personnel can draw samples and have them analyzed quickly.
A disadvantage is that the relationship between the solvent fraction and
organic emissions is not linear.  If the organic solvent content is expressed
in terms of mass of organic solvent per unit volume of paint solids (kgs per
liter or Ibs per gallon of solids), the disparity disappears.  This relationship
is linear and more readily understood, e.g., a coating containing 2 Ibs of
organic solvent per gallon of solids releases twice as much organic solvent
as one with one pound per gallon.  The disadvantage of this format, however,
is that the analytical methods are more complex.  Appendix A of Volume II
of this series, "Control of Volatile Organic Emissions from Existing Stationary
Sources - Volume II:  Surface Coating of Cans, Coils, Paper, Fabrics,
Automobiles,, and Light-Duty Trucks," presents ASTM test methods that permit
determination  of the organic solvent per gallon of coating (minus water).
                                   6-1

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      For miscellaneous metal part and product coating facilities,  it is
recommended that, if possible, emission limitations should be expressed
in terms of the organic solvent content of the coating since these values
can be determined with relatively simple analytical techniques.  Alternative
compliance procedures should permit operators to use add-on control equip-
ment if they so choose.  (Sample calculations to verify compliance with
this type of emission limit are shown in Appendix A of this document.)
      Other options such as mass or volume of organic solvent per mass
of coating are generally less desirable although they may be entirely
appropriate for a given industry.  Basing limitations on the mass of
coating or paint solids is not generally recommended because the specific
gravity of a coating solids tends to vary widely with the degree and type of
pigment employed.  Highly pigmented paints have much greater density than
unpigmented clear coats or varnishes.
      The recommended limitations assume the miscellaneous metal part and
product facilities merely convert an organic-borne coating to a coating
low in organic solvent.  They do not consider the reduction in VOC emissions
which would result from a decrease in film thickness or an increase in the
transfer efficiency of a coating.  For example, assume a facility  applying
conventional coating at 1.2 mils film thickness, converts to a coating
which, although it contains  less organic solvent, does not quite meet the
recommended emission limit.   If the  new coating is serviceable when applied
in a thinner coat, it may result in  a reduction in VOC emissions comparable
to or even greater than a coating which meets the recommended  emission  limit,
      Another example would  be the emission reductions that accrue from
improved coating techniques.  A facility that converts from  a  conventional
manual spray application (at  a transfer efficiency of 40-70  percent)  to  an
                                     6-2

-------
automated electrostatic spray system (at a transfer efficiency of 70-90
percent), or from any spray system to a flow or dip coat system (at a
transfer efficiency of at least 90 percent) would realize a significant
reduction in VOC emissions.  All of these possibilities should be considered
in any evaluation of the overall reduction achieved by the operator.
     In those few facilities where add-on control equipment is a more
likely option, it may be more appropriate to state emission limits in terms
of control efficiency across the incinerator, adsorber, etc.  Otherwise,
where limitations are expressed only in terms of the solvent content of the
coating, it would be necessary to determine the mass emission rate from the
control system and relate it to the quantity of coating applied during
the test period.  This is a more complicated procedure since it may not be
easy to determine the amount of coating consumed during the test period and
an analysis by mass of the organic solvent directed to the control device
would be even more difficult.  Chapter 5 of "Control of Volatile Organic
Emissions from Existing Stationary Sources - Volume I:  Control Methods
for Surface Coating Operations" presents approaches which may be used.
When add-on type devices are selected  as the compliance method, the air
pollution control agency should require that the coating  lines be  equipped
with an  approved capture device to assure  effective containment.   The  capture
system will likely have to be  custom designed  to accommodate  the  individual
plant variables which affect performance.  When reviewing the design of such
a system, however, the air pollution control official must  also consider
requirements  imposed by the Occupational Safety and Health Administration
and the  National Fire Prevention Association.
     It  is recognized that some coatings will emit  more  VOC  than merely its
solvent  content.  This incremental VOC may come from three  possible  sources.
                                  6-3

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The first is the possibility that some of the monomer may evaporate.   Also,
if the film forms by condensation polymerization, the evolution of by-products
may be a compounding factor.  Finally, it has been reported that the industry
is using increasing quantities of "blocking agents" which are released from
the polymer matrix during the curing process.
     There are now no approved analytical methods certified by the agency
for determining the quantity of VOC emitted by such reactions although
certainly the organic mass emission rate could be determined by expensive
and sophisticated analytical techniques.  The more practical means of
quantifying the contribution of the polymerization reaction to the overall
emission problem would be by contacting the manufacturer of the coating.
Certainly, his knowledge of the fundamental chemical mechanisms involved
would allow calculation of an emission rate based on the chemical reaction.
     This emission will occur during the cure (if at all) which is usually
temperature initiated by the oven.  If the oven  is controlled by an incinerator,
then verification of the efficiency of the device should be sufficient to
assure compliance with the coating regulations.
                                6-4

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                           APPENDIX A
             SAMPLE CALCULATIONS OF CONTROL OPTIONS

      This appendix will aid the local agency in determining if a coating
proposed for use by a miscellaneous metal part or product facility will
meet a recommended emission limit.  It also explains how to compare the
actual VOC emissions from a facility regardless of the type of low-polluting
coating or add-on control device used.
      The purpose of all coating operations is to cover a substrate with a
film that provides both corrosion resistance  to the substrate and
esthetic appeal.  Therefore, the rational basis for specifying an allowable
VOC emission limit would be in units of coating volume (e.g., grams of
VOC per square meter (Ibs/sq. ft) per unit thickness of film).  However,
the complexity of any analytical method which would provide a measurement
of the volume of a cured coating precludes this approach.  As a compromise,
the limitations were developed in terms of mass of VOC per unit volume of
uncured solids and organic solvent.  Mathematically, then, the emission
factor (ef) for a coating would be expressed as:
    m ef = (^urne ^action organic sol vent) (average organic solvent density)
    * '      volume fraction of solids + volume fraction of organic solvent
    (2} ef   (volume fraction organic solvent) (average organic solvent density)
    ^ '    "                      1- volume fraction of water
      The following examples show the use of these equations to determine
the emission factor for both organic solvent-borne and water-borne coatings.
We will assume the applicable emission limitation is 0.34 kg/liter.  This
represents a low solvent coating with 0.62 v/v solids content.
                                  A-l

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CASE 1:  Determine the emission factor for an organic solvent-borne coating
which contains 35 volume percent organic solvent.
      Therefore: ef = (.35)(0.88_kg/liter*)
                    = 0.31 kgs/liter (2.6 Ibs/gal)
      Since the emission factor is less than the recommended limit of
0.34 kg/liter (2.8 Ibs/gal), this coating is in compliance.

CASE 2:  Determine the emission factor for a water-borne coating containing
25 volume percent solids.  Of the 75 percent solvent, 80 volume percent
is water and 20 percent is organic solvent.
      Since 80 percent of the solvent is water, the respective volumes of
water and organic solvent may be calculated as shown:
      Volume water = .80 x .75 liter = .6 liter
      Volume organic solvent = 0.75 liter - .6 liter = .15 liter
      Therefore:  ef = (0.15H0.88 kg/liter)*
                             I - u.o
                     = 0.32 kg/liter (2.64 Ibs/gal)
This coating also has an emission factor less than the recommended limit
and would comply.
      The level of control represented by 0.34 kg/liter of coating
(2.8 Ibs/gal) less water can also be achieved with a conventional high
organic solvent coating if suitable add-on control equipment is installed.
However, this method of determining the equivalent emission limit factor
is not as straightforward as the previous two cases and must also consider
the volume of solids in the coating.

CASE 3:  Determine the emission factor for a conventional organic-borne
coating containing 75 volume percent organic solvent.
*This density is considered typical and is equal to 7.36 Ibs/gal.
                                   A-2

-------
      TU           *   (.75H.88 kg/liter)
      Therefore:  ef = N    M-] _ A*	L

                     = 0.66 kg/liter (5.5 Ibs/gal)

      However, this liter of coating contains only 0.25 liter of solids

whereas the low-solvent coating which the recommended emission limit of

0.34 kg/liter (2.8 gal) represented would contain 0.62 liter of solids.



           (The fraction of solids in the low solvent coating can be back  calcu-

            lated from the recommended emission limit in the following manner.)
           IP     n ™ - (*)(0.88 kg/liter)
           I * C • 9   U • OH"        j-uj  ---^_


                      x = 0.38, volume percent organic solvent

           Therefore, fraction of solids = 1 - x = 0.62.



On a unit volume of solids basis, the conventional coating contains:


    0.66 kg organic solvent  _  2.64 kg organic solvent  or 22 Ibs VOC
       0.25 Titer solidsliter solidsgal solids

And the recommended limit reference coating contains only:


    0.34 kg organic solvent  _ 0.55 kg organic solvent  or 4.6 Ibs VOC
       0.62 liter solidsliter solidsgal solids


      Consequently, in order for a facility to use the conventional coating

yet emit no more VOC than the  reference coating, the add-on control device

must capture and destroy (or collect) 2,09 kg of solvent  per  liter of  solids

applied (2.64 - 0.55).  This will require a control  system that  is at  least

79 percent efficient.  Since the add-on control devices  can often operate

at 90 percent efficiency or greater, the agency must insure that at least

88 percent of the VOC emitted  by the coating is captured  and  delivered to

the add-on control device.  Since it will   often  not be practical to

attempt the complex analytical program essential to  develop  a material
                                   A-3

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balance around the coating application and flashoff areas and ovens,

the agency may certify an acceptable capture system based on good

engineering practice.
APPENDIX A REFERENCE

1.  Young, Dexter E., Environmental Protection Agency, memorandum
    concerning requirements for ventilation of spray booths and
    ovens.  Dated March 10, 1977.
                                      A-4

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                                   TECHNICAL REPORT DATA
                            {Please read Instructions on the reverse before completing)
1. REPORT NO,
     EPA-450/2-78-015
                                                           3. RECIPIENT'S ACCESSIOWNO,
4, TITLE AND SUBTITLE
     Control of Volatile  Organic Emissions  from Existing
     Stationary Sources  - Volume VI: Surface  Coating of
     Miscellaneous Metal  Parts and Products
             5. REPORT DATE
               June.  1978
             6. PERFORMING ORGANIZATION CODE
7, AUTHORIS!

     Vera Gallagher,  John  Pratapas
                                                           8. PERFORMING ORGANIZATION REPORT NO.
               OAQPS No. 1.2-101
9. PERFORMING ORGANIZATION NAME AND ADDRESS
     U.S. Environmental  Protection Agency
     Office of Air  and Waste Management
     Office of Air  Quality Planning  and Standards
     Research Triangle Park, No'rth Carolina  27711
                                                            10. PROGRAM ELEMENT NO.
             11, CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
                                                            13. TYPE OF REPORT AND PERIOD COVERED
                                                            14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16, ABSTRACT
          This document provides the necessary guidance for  development of
     regulations  to  limit emissions of  volatile organic compounds  (VOC) from
     the coating  operations of miscellaneous  metal parts and products.  This
     guidance includes  emission limits  which  represent Reasonably  Available
     Control Technology (RACT) for the  miscellaneous metal part and product
     Industries,  describes the industries,  shows the methods  by which VOC
     emissions can be reduced in these  industries and describes the monitoring
     and enforcement aspects.
17,
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.IDENTIFIERS/OPEN ENDED TERMS
                           c. COSATI Field/Group
     Air Pollution
     Miscellaneous  Metal  Part and Product
         Industries
     Volatile Organic Compound Emission
         Limits
     Regulatory Guidance
   Air Pollution Control
   Stationary Sources

   Organic Vapors
18. DISTRIBUTION STATEMENT
     Unlimited
                                               19. SECURITY CLASS (This Report)
                                                 Unclassified
                                                                          21. NO. OF PAGES
20. SECURITY CLASS t
  ii   T    « ** •   t
  Unclassified
                           22. PRICE
EPA Form 2220-1 (9-73)

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United States                                Office of Air, Noise, and Radiation
Environmental Protection                     Office of Air Quality Planning and Standards
Agency                                     Research Triangle Park NC 27711
Official Business                            Publication No  EPA-450/2-78-015                                                                                           Postage and
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                                                                                                                                                                      Protection
                                                                                                                                                                      Agency
                                                                                                                                                                      EPA 335
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