United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park, NC 27711
EPA-453/D-95-004
"May 1995
Air
•ERA Flexible Polyurethane Foam
Emission Reduction Technologies
Cost Analysis
PRELIMINARY DRAFT
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U.S. Environmental Protection Agency
Region 5, Library {PL- 12J)
77 West Jackson Boulevard, 12th Floor
ChicagoJL 60604-3590
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DISCLAIMER
This report has been reviewed by the Emission Standards Division
of the Office of Air Quality Planning and Standards, EPA, and
approved for publication. Mention of trade names and commercial
products is not intended to constitute endorsement or
recommendation for use. Copies of this report are available
through the Library Services Office (MD-35), U.S. Environmental
Protection Agency, Research Triangle Park, N.C. 27711, or from
National Technical Information Services, 5285 Port Royal Road,
Springfield, Virginia 22161.
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TABLE OF CONTENTS
Page
LIST OF TABLES ....................... iv
LIST OF FIGURES ....................... vi
1.0 INTRODUCTION ...................... 1-1
1.1 PURPOSE OF DOCUMENT ................ 1-1
1.2 DOCUMENT CONTENTS ................. 1-1
2.0 BACKGROUND ....................... 2-1
2.1 INDUSTRY DESCRIPTION ............... 2-1
2.2 FOAM GRADES AND APPLICATIONS ........... 2-2
2.3 CHEMISTRY OF POLYURETHANE FOAM PRODUCTION ..... 2-3
2.4 BLOWING AGENTS .................. 2-4
2.5 FOAM QUALITY MEASUREMENTS ............. 2-6
2.6 CURRENT ENVIRONMENTAL RELEASES .......... 2-6
2.7 REFERENCES .................... 2-8
3.0 REPRESENTATIVE FACILITIES ............... 3-1
3.1 DEVELOPMENT OF REPRESENTATIVE FACILITY PARAMETERS . 3-1
3.2 DEVELOPMENT OF REPRESENTATIVE FACILITY COSTS . . .3-1
3.3 REFERENCES FOR CHAPTER 3.0 ............ 3-5
4.0 EMISSION REDUCTION TECHNOLOGIES AND COSTS: MOLDED
FOAM .......................... 4-1
4.1 ALTERNATIVES TO HAP MIXHEAD FLUSHES ........ 4-1
4.1.1 Non-HAP Mixhead Flushes ......... 4-2
4.1.2 High-Pressure (HP) Mixheads ....... 4-3
4.1.3 "Self -Cleaning" Mixhead ......... 4-6
4.1.4 Solvent Recovery Systems ........ 4-9
4.2 ALTERNATIVE MOLD RELEASE AGENTS ......... 4-11
4.2.1 Reduced-VOC Mold Release Agents .... 4-11
4.2.2 Naphtha-based Release Agents ..... 4-13
4.2.3 Water-based release agents ...... 4-13
4.3 ALTERNATIVE ADHESIVES .............. 4-15
4.3.1 Hot -Melt Adhesives .......... 4-17
4.3.2 Water-Based Adhesives ......... 4-19
4.4 REFERENCES FOR SECTION 4.0 ........... 4-23
5.0 EMISSION REDUCTION TECHNOLOGIES AND COSTS: SLABSTOCK
FOAM .......................... 5-1
5.1 ALTERNATIVES TO METHYLENE CHLORIDE AS AN ABA . . . 5-1
5.1.1 Acetone as an ABA ............ 5-1
5.1.2 Liquid CO2 as an ABA .......... 5-3
5.1.3 Foaming in a Controlled Environment . . . 5-5
5.1.3.1 Variable Pressure Foaming (VPF) . . 5-5
5.1.3.2 Controlled Environment Foaming
(CEF) ............... 5-8
5.1.4 Forced-Cooling ............ 5-10
5.1.5 Chemical Modifications ........ 5-15
U.S. Environ mental Protection Agency
Region 5, Library (PL- 12 J)
77 West Jackson Boulevard, 12th Floor
Chicago, IL 60604-3590
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5.2 EQUIPMENT CLEANERS 5-16
5.2.1 Steam Cleaning 5-19
5.2.2 Non-HAP Cleaners 5-19
5.3 REFERENCES 5-22
6.0 SUMMARY 6-1
6.1 MOLDED FOAM 6-1
6.2 SLABSTOCK FOAM 6-4
6.3 REFERENCES 6-6
111
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LIST OF TABLES
TABLE 2-1 SUMMARY OF HAP EMISSIONS FROM FLEXIBLE POLYURETHANE
FOAM PRODUCTION 2-7
TABLE 3-1 REPRESENTATIVE SLABSTOCK FACILITY PARAMETERS ... 3-2
TABLE 3-2 FORMULATION INFORMATION FOR THE REPRESENTATIVE
SLABSTOCK FACILITY 3-3
TABLE 3-3 REPRESENTATIVE MOLDED FACILITY PARAMETERS 3-4
TABLE 3-4 CONTRIBUTIONS TO TOTAL CAPITAL INVESTMENT 3-6
TABLE 3-5 CONTRIBUTIONS TO TOTAL ANNUAL COST 3-7
TABLE 4-1 REPRESENTATIVE FACILITY COSTS FOR NON-HAP MIXHEAD
FLUSHES 4-4
TABLE 4-2 REPRESENTATIVE FACILITY COSTS FOR HIGH PRESSURE
MIXHEADS 4-7
TABLE 4-3 REPRESENTATIVE FACILITY COSTS FOR SELF-CLEANING
MIXHEADS 4-8
TABLE 4-4 REPRESENTATIVE FACILITY COSTS FOR SOLVENT RECOVERY
SYSTEMS 4-10
TABLE 4-5 REPRESENTATIVE FACILITY COSTS FOR REDUCED-VOC MOLD
RELEASE AGENTS 4-12
TABLE 4-6 REPRESENTATIVE FACILITY COSTS FOR NAPHTHA-BASED MOLD
RELEASE AGENTS 4-14
TABLE 4-7 REPRESENTATIVE FACILITY COSTS FOR WATER-BASED MOLD
RELEASE AGENTS 4-16
TABLE 4-8 REPRESENTATIVE FACILITY COSTS FOR HOT-MELT
ADHESIVES 4-18
TABLE 4-9 REPRESENTATIVE FACILITY COSTS FOR WATER-BASED
ADHESIVES 4-20
TABLE 4-10 REPRESENTATIVE FACILITY COSTS FOR HYDROFUSE
ADHESIVE 4-22
TABLE 5-1 REPRESENTATIVE FACILITY COSTS FOR ACETONE AS
AN ABA 5-4
TABLE 5-2 REPRESENTATIVE FACILITY COSTS FOR CARDIO™ .... 5-6
TABLE 5-3 REPRESENTATIVE FACILITY COSTS FOR VARIABLE PRESSURE
FOAMING 5-9
IV
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TABLE 5-4 REPRESENTATIVE FACILITY COSTS FOR CONTROLLED
ENVIRONMENT FOAMING 5-11
TABLE 5-5 REPRESENTATIVE FACILITY COSTS FOR
ENVIRO-CURE® 5-14
TABLE 5-6 REPRESENTATIVE FACILITY COSTS FOR CHEMICAL
MODIFICATIONS 5-17
TABLE 5-7 REPRESENTATIVE FACILITY COSTS FOR NON-HAP
CLEANERS 5-18
TABLE 6-1 SUMMARY OF REPRESENTATIVE FACILITY COSTS FOR MOLDED
FOAM EMISSION REDUCTION TECHNOLOGIES 6-2
TABLE 6-2 SUMMARY OF REPRESENTATIVE FACILITY COSTS FOR SLABSTOCK
FOAM EMISSION REDUCTION TECHNOLOGIES 6-3
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LIST OF FIGURES
FIGURE 2-1 Polyurethane Foam Production Reactions .... 2-3
VI
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1.0 INTRODUCTION
1.1 PURPOSE OF DOCUMENT
This document describes the costs of hazardous air pollutant
(HAP) emission reduction technologies for flexible polyurethane
foam production facilities. The U.S. Environmental Protection
Agency (EPA) reviewed information from the information collection
request (ICR) responses that were received from flexible
polyurethane foam producers, as well as the information contained
in other pertinent project files, to identify potential HAP
emission reduction and control technologies. The universe of all
possible technologies was narrowed to include only technologies
that are currently being used, or those under investigation that
are generally considered to be promising. Information on cost
and emission reduction potential, as well as process and
operational information, was compiled for each technology.
Information was collected from chemical manufacturers, product
vendors, trade associations, foam producers, and other sources.
The majority of the information was gathered by telephone
communication.
Once the information was collected, it was analyzed and
applied to "representative" facilities to evaluate the capital
and operational costs, as well as the emission reduction and cost
effectiveness, of each alternative. In several instances, the
information provided was insufficient to permit an analysis of
the total capital investment and total annual costs. Therefore,
certain assumptions were necessary to allow the calculation of
the representative facility costs. Where possible, assumptions
were based on statements or partial information from industry and
other contacts.
1.2 DOCUMENT CONTENTS
The comments of the vendors, manufacturers, and foam
producers who had contributed to the original analysis were
collected, and these have been incorporated into this document.
Chapter 2 provides background on the industry. Chapter 3
describes the development of "representative" molded and
1-1
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slabstock facilities, and the calculation of representative
facility costs. Chapters 4 and 5 provide brief descriptions for
each technology, along with costs for the representative
facilities. Chapter 6 summarizes the analysis.
1-2
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2.0 BACKGROUND
2.1 INDUSTRY DESCRIPTION
The term "polyurethane" is applied to a general class of
polymers in which molecular chain segments are bound together
with urethane linkages. Polyurethanes are used to produce an
extremely wide range of products, including solid plastics,
adhesives, coatings, rigid foams, and flexible foams. Flexible
foams represent by far the largest application for polyurethanes,
accounting for over half of the total U.S. production of
polyurethanes.l Flexible polyurethane foam is used in
furniture, bedding, automobile seats and cushions, packaging
materials, and carpet underlay.2 Another on-site operation at
slabstock facilities is rebond. Rebond is a process that
combines ground scrap foam and pieces and toluene diisocyanate
(TDI) under steam and pressure to create a bonded material. This
material is used to produce carpet underlay.
The flexible polyurethane foam industry can be divided into
two major segments: slabstock foam production and molded foam
production. Slabstock foam is produced in large "buns" that
range in size from 300 cubic feet to over 5000 cubic feet. After
they cure, the buns are cut, glued, or otherwise "fabricated"
into the particular shapes and sizes for the desired end-use.
Fabrication operations may be carried out by the slabstock plant
itself, or by the foam purchaser. The largest uses of slabstock
foams are in furniture, carpet underlay, and bedding.3
In molded foam production, the foam polymerization reaction
is carried out in a mold in the shape of the desired product.
This minimizes the need for fabricating the foam, although
shaping and gluing operations may still be required. Molded foam
is used primarily in the transportation market for car seats,
cushions, and energy-absorbing panels; however, it is also used
for novelty items, in office furniture, and in medical
products.4
Total slabstock foam production in 1992 was approximately
550,000 tons. At the end of 1992, there were 25 companies
2-1
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engaged in slabstock foam production, operating about 78 foam
plants. Three large companies account for over half of the total
U.S. production.
The production of molded foam is more difficult to quantify,
because there are many small plants. The Society of the Plastics
Industry, Inc. (SPI) reported production of molded foam at
215,000 tons in 1989. A recent survey of the foam industry by
the EPA's Emission Standards Division (BSD) identified 49 plants
producing molded foam. However, these plants accounted for only
about half of the molded foam production reported by SPI in 1989.
Estimates of the total number of plants producing molded foam
range up to 200. Molded producers tend to be either quite large,
or quite small. In the EPA/ESD survey, almost half of the 49
plants surveyed reported production rates less than 500 tons per
year.
2.2 FOAM GRADES AND APPLICATIONS
Flexible polyurethane foam is produced in a wide range of
grades which are usually identified by two parameters: density
and firmness. Foam densities range from less than 1 pound per
cubic foot to more than 3 pounds per cubic foot. Higher density
foams are typically more durable than lower density foams,
because they contain more mass of polymer per unit volume.5
However, the higher density foams require more raw materials, and
hence have higher production costs.
The firmness of a foam determines its load bearing ability.
This parameter is also related to the foam's softness. The most
common measure of firmness is the "indentation force deflection"
(IFD) . This is the force required for a 50 square inch disk to
cause a certain percentage of indentation in a foam block.
Indention force deflection is expressed in pounds (per square
inch), and can range from 20 pounds to over 100 pounds.
Different grades of foam have different primary
applications; however, there is no strict relationship between
the grade and the application. For instance, the density of foam
used for seat cushioning can range from 1 pound per cubic foot to
3 pounds per cubic foot, depending on quality and other
2-2
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specifications.
In general, lower density and softer foams are used for seat
backs and arm rests. Low density, stiff foams are well suited
for packaging. Foams with moderate density and load bearing
capacity are used for seat cushions and bedding. Higher density
foams are generally used for carpet packing, and other heavy-duty
applications.
2.3 CHEMISTRY OF POLYURETHANE FOAM PRODUCTION
Polyurethanes are made by reacting a polyol with a
diisocyanate. For slabstock foam production, the polyol is
typically a polyester or a polyether with two or more hydroxyl
groups, and the diisocyanate is usually a mixture of 2,4- and
2,6- isomers of toluene diisocyanate (TDI), with the ratio being
80 percent 2,4- to 20 percent 2,6-. Molded foam producers
frequently use methylene diphenyl diisocyanate (MDI) rather than
TDI.
Polyurethane foams are made by adding water to the polyol
and diisocyanate mixture. Once the ingredients are mixed, two
main polymerization reactions occur. Isocyanate groups react
with hydroxyl groups on the polyol to produce urethane linkages
(hence the term polyurethane). The other main reaction is that
of the isocyanate and water. The initial product of the reaction
with water is a substituted carbamic acid, which breaks down into
an amine and carbon dioxide (CO2) . The amine then reacts with
another isocyanate to yield a substituted urea linkage. These
reactions are illustrated in Figure 2-1.
Surfactants and catalysts are also added to the mixture.
The surfactants aid in mixing incompatible components of the
reaction mixture and also help control the size of the foam cells
by stabilizing the forming gas bubbles. Catalysts balance the
isocyanate/water and isocyanate/polyol reactions and assist in
driving the polymerization reaction to completion.
The C02 formed in the initial reaction acts as the "blowing
agent" and causes the bubbles to expand. The bubbles eventually
come into close contact, forming a network of cells separated by
thin membranes. At full foam rise, the cell membranes are
2-3
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stretched to their limits and rupture, releasing the blowing
agent and leaving open cells supported by polymer "struts."
The more water added and CO2 formed, the more expanded the
polymer network, and the lower the resultant density. However,
the reaction of isocyanate with water is very exothermic. The
addition of too much water can cause the foam to scorch or even
auto-ignite.
The final polymer is composed of the urethane and urea
linkages formed in the isocyanate/polyol and isocyanate/water
reactions. The polyol-to-isocyanate urethane linkages provide
strength, and the isocyanate-to-isocyanate urea linkages give the
foam its firmness.
The amount of each ingredient used in a foam formulation
varies, depending on the grade of foam desired. Foam
formulations are generally denoted by the number of parts (by
weight) of diisocyanate and water used, per 100 parts polyol.
2.4 BLOWING AGENTS
The gas which expands the polyurethane polymer to produce a
foam is termed a "blowing agent." As noted in the previous
section, one result of the isocyanate-water reaction is the
{R}-N=C=0 + H2O ->
o
Reactions of isocyanate with water
o
{R}-N=C=0 + {P}-OH -+ {R}-N-C>
Isocyanate Polyol
Reaction of isocyanate with polyol
Figure 2-1. Polyurethane foam production reactions
2-4
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liberation of CO2 gas. The blowing action of this CO2 is termed
"water-blowing," because the CO2 blowing agent is produced from
the isocyanate-water reaction. Many grades of foam can be
produced using only this CO2 gas as a blowing agent.
Increasing the amount of water in a formulation generally
produces a lower-density foam, because additional CO2 blowing
agent is produced. However, there is a practical limit to the
amount of water that can be used. First, an increase in the
water level results in an increase in the number of urea linkages
in the final polymer. These linkages tend to make the polymer
stiffer because they undergo hydrogen bonding. Second, the
isocyanate-water reaction is extremely exothermic. An excessive
level of water can cause high temperatures that can scorch the
foam, or even cause the foam to ignite.
As a result, some grades of foam require the use of an
auxiliary blowing agent (ABA) . The ABA is mixed with the foam
reactants as a liquid when the reactant mixture is first poured.
As the exothermic polymerization reactions raise the temperature
of the polymer mass, the ABA vaporizes, supplementing the blowing
action of CO2 from the water-isocyanate reaction. The
vaporization of the ABA also serves to remove excess heat from
the foam, reducing the potential for scorching or auto-ignition.
Auxiliary blowing agents are more widely used in the
production of slabstock foams than in the production of molded
foams. The amount of ABA required depends on the grade of foam
being produced and the ABA used. Auxiliary blowing agents are
most important for low density and soft foams. In these grades,
water-blowing alone would cause problems with either overheating
or with increased foam stiffness.
Previously, the principal ABA used was chlorofluorocarbon 11
(CFC-11). However, since this compound has been shown to deplete
the earth's ozone layer, U.S. producers have almost completely
phased out its use. Methylene chloride, a listed HAP, has
replaced CFC-11 as the principal ABA. The consumption of
methylene chloride for slabstock ABA applications in 1992 was
approximately 14,500 tons. The second largest volume ABA in 1992
2-5
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was 1,1,1-trichloroethane (TCA), at approximately 2,000 tons.
Since the role of the ABA is simply to volatilize and expand the
foam, it does not directly participate in the polyurethane
reaction. Therefore, all of the ABA that is added eventually is
emitted. Releases of HAP ABA's to the atmosphere are substantial
(over 16,800 tons in 1992).
2.5 FOAM QUALITY MEASUREMENTS
In their evaluations of technologies to reduce or eliminate
blowing agents, foam producers are sensitive to any potential
degradation in foam quality. A number of physical properties are
measured as indicators of foam quality. These include
resilience, hysteresis, dynamic fatigue, air flow, tensile
strength, elongation, and tear strength.
2.6 CURRENT ENVIRONMENTAL RELEASES
Emissions to the atmosphere constitute the major
environmental release from flexible polyurethane foam
manufacturing. The bulk of emissions from the industry result
from the use of ABAs, mainly in the manufacture of slabstook
foam. However, substantial emissions also result from the use of
organic solvents in adhesives and equipment cleaning operations.
Table 2-1 gives a summary of emissions from different operations
in slabstock and molded foam production. The emissions reported
for hazardous air pollutants in Table 2-1 are based on a recent
survey of these emissions by the EPA's Emission Standards
Division.6*7 Emissions of freons are based on sales figures and
company reports to EPA's Toxics Release Inventory.8
There are no process wastewater discharges from this
industry. The water used in the foam reaction is entirely
consumed in that reaction. Water is used in some cases for non-
contact cooling of foam reactants, but no discharges are reported
from these systems.
Solid waste generated by foam production processes is
minimized, because most scrap is used in rebond operations. Foam
production lines occasionally produce bad batches, which are
unsuitable even for rebonding. This material must be treated as
a hazardous waste under the Resource Conservation and Recovery
2-6
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TABLE 2-1.
SUMMARY OF HAP EMISSIONS FROM FLEXIBLE POLYURETHANE
FOAM PRODUCTION - 1992a
Emission Source
Total
emissions
(tons/yr)
Primary chemicals
Slabstock foam
Blowing agent
Fabrication
Chemical storage
and handling
Rebond operations
Slabstock foam
total
Methylene chloride,
16,968 methyl chloroform
1,401 Methyl chloroform
49 Methylene chloride, TDI
11 Methylene chloride, TDI
18,429
Molded foam
Equipment flushing
and cleaning
Mold release
Chemical storage
and handling
In-mold coating
Foam repair
Other
Molded foam
total
205 Methylene chloride
8 Methylene chloride
12 MDI, TDI
6 MEK, Toluene
27 Methyl chloroform
10 MDI, methylene chloride
268
INDUSTRY TOTAL
18,697
Data Source: Non-Confidential Summary of Flexible
Polyurethane Foam Information Collection Request (ICR) Data,
prepared by EC/R Inc. February 10, 1995.
2-7
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Act (RCRA), because it may contain some unreacted isocyanate. In
addition, some solvent waste subject to RCRA is produced from
equipment cleaning operations. These wastes are generally
shipped off-site for treatment or disposal.
2.7 REFERENCES
1. SPI. 1990 End-Use Market Survey on the Polyurethane Industry
in the U.S. and Canada. The Society of the Plastics Industry
- Polyurethane Division.
2. Reference 1.
3. Reference 1.
4. Reference 1.
5. Kreter, P.E. 1985. Polyurethane Foam Physical Properties as
a Function of Foam Density. In: Proceedings of the SPI -
32nd Annual Technical/Marketing Conference. The Society of
the Plastics Industry, Inc., Polyurethanes Div. pp. 129-133.
6. Norwood, L.P., et al (EC/R Inc.). Summary of Flexible
Polyurethane Foam Information Collection Requests (ICRs).
Presented at a meeting of EPA and the Polyurethane Foam
Association. February 2, 1994.
7. Williams, A. (EC/R Inc.) Updated Estimates of HAP Emissions
from Slabstock Foam Production. Letter to Lou Peters,
Polyurethane Foam Association. February 8, 1994.
8. Toxics Release Inventory. U.S. Environmental Protection
Agency, Office of Toxic Substances, Washington, D.C. 1992.
2-8
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3.0 REPRESENTATIVE FACILITIES
3.1 DEVELOPMENT OF REPRESENTATIVE FACILITY PARAMETERS
One purpose of this analysis was to estimate the impacts of
the targeted emission reduction technologies on any individual
facility. In order to conduct this study, "representative"
slabstock and molded facilities were developed. The
representative facilities only include those parameters needed to
estimate representative facility costs.
In general, the parameters for the representative facilities
were based on information provided in response to the ICR.1
Where possible, the parameters are averages of the ICR responses
In some instances, assumptions were made based on knowledge
gained during plant visits. In other cases, parameters are based
on detailed information from an individual facility. For the
representative slabstock facility, Polyurethane Foam Association
(PFA) members provided input that affected the representative
facility foam formulations. Table 3-1 shows the representative
slabstock facility, Table 3-2 shows formulation information for
the representative slabstock facility, and the representative
molded facility is described in Table 3-3.
3.2 DEVELOPMENT OF REPRESENTATIVE FACILITY COSTS
There were no specific precedents to follow in the
development of representative facility costs for process
modifications. The OAQPS Control Cost Manual provided general
guidance on the estimation of total capital investment and annual
costs.2
Total capital investment includes three basic elements: (l)
purchased equipment costs, (2) direct installation costs, and
(3) indirect installation costs. Total capital investment may
also include costs for land, working capital, and off-site
facilities. The total annual cost consists of three elements:
(1) direct costs, (2) indirect costs, and (3) recovery credits.
In the OAQPS manual, most components of the total capital
investment are based on the purchased equipment costs. While the
cost factors in the manual were developed for specific types of
3-1
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TABLE 3-1. REPRESENTATIVE SLABSTOCK FACILITY PARAMETERS
Value
Basis
OPERATING PARAMETERS
Foam produced
Operating schedule
Number of lines
Speed of line
Line electricity use
MeCl2 used as ABA
MeCl2 used as
cleaner
Waste MeCl2 from
cleaning
Amount of foam
fabricated
Amount of adhesive
used for fabrication
HAP content of
adhesive
Number of spray booths
Fabrication operating
schedule
7,500 tons/yr ICR average
4 hrs/day actual ICR averages, plant visits
pouring
225 days/yr
1 (Maxfoam) plant visits, ICR
15 feet/min plant visits
120 kw
325 tons/yr
provided by foamer
calculated using formulations in Table
3-2
5 tons/yr EPA assumption
2 55-gal
drums/yr
3,520 tons/yr
10,679 gallons
70%
6
16 hours/day 225
days/yr
foamer estimate that 10 percent by
volume of total MeCl2 used as cleaner
is not recoverable
based on a facility that provided
detailed adhesive usage information
based on a facility that provided
detailed usage information
based on a facility that provided
detailed adhesive usage information
plant visits, ICR
plant visits, ICR
COST PARAMETERS
Total chemical cost
ABA-blown chemical
cost
Operating costs
Cost of MeCl2
Disposal cost of
waste MeCl2
Cost of HAP adhesive
$10.8 million/yr calculated from information provided by
PFA chemical alternative informational
work group
$9.78 million/yr calculated from information provided by
PFA chemical alternative informational
work group
$2.7 million/yr calculated using the total chemical
cost and the PFA assumption that 80
percent of total costs are chemical
costs
$0.25/lb
$800 per
55-gal drum
$8.5/gal
PFA chemical alternative suppliers
informational work group
vendor estimate
vendor quote
EMISSIONS
MeCl2 from ABA
MeCl2 emissions from
cleaning
HAP emissions from
fabrication
325 tons/yr all used is emitted
4.5 tons/yr 90 percent of used (remainder is waste)
43 tons based on a facility that provided
detailed adhesive usage information
3-2
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TABLE 3-2. FORMULATION INFORMATION FOR THE
REPRESENTATIVE SLABSTOCK FACILITY*
Grade Density
(pcf)
0930
1010
1015
1020
1030
1120
1130
1230
1330
1340
1440
1520
1530
1540
1640
1740
1820
1830
1840
1930
1940
0.9
1.0
1.0
1.0
1.0
1.1
1.1
1.2
1.3
1.3
1.4
1.5
1.5
1.5
1.6
1.7
1.8
1.8
1.8
1.9
1.9
2.0
IFD amount MeCl2 MeCl2
(25%) produced (pph polyol) emitted
(tons/yr) (tons/yr)
30
10
15
20
30
20
30
30
30
40
40
20
30
40
40
40
20
30
40
30
40
>20
TOTALS
440
220
360
230
680
370
170
610
300
110
180
170
510
390
220
170
160
510
570
240
150
740
7,500
10
22
19
14
8
14
7
5
6
2
2
13
6
2
1
1
10
6
1
7
1
0
29.3
32.3
44.4
21.5
34.0
33.3
7.4
20.3
11.0
1.5
2.4
14.2
20.4
5.2
1.5
1.1
10.7
18.7
3.8
11.2
1.0
0.0
325
Assuming 67 percent of foam weight is polyol.
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TABLE 3-3. REPRESENTATIVE MOLDED FACILITY PARAMETERS
Value
Basis
OPERATING PARAMETERS
Type of foam products
Foam produced
Number of lines
(carrousels)
Operating schedule
Type of mixheads
Mixhead delivery
MeCl2 used as mixhead
flush
Waste MeCl2
Amount of mold release
agent used
HAP content of mold
release agent
Number of repair
stations
Amount of adhesive used
for foam repair
HAP content of adhesive
COST PARAMETERS
Cost of MeCl2
Disposal cost of waste
MeCl2
Cost of HAP-based mold
release agent
Cost of Adhesive
EMISSIONS
MeCl2 emissions from
mixhead flush
HAP emissions from mold
release agents
HAP emissions from foam
repair
non-automotive
specialty parts
800 tons/yr
3: 1 does not use
HAP-based mold
release agents
2 lines - 8 hrs/day
1 line - 15 hrs/day
240 days/yr
low-pressure
9 to 26 Ibs/min
135 55-gal drums/yr
13 55-gal drums/yr
1,588 gal/yr
75%
345 gal/yr
70%
$0 .36/lb
$800/
55-gal drum
$4.82/gallon
$8.50 per gallon
37.1 tons/yr
4.6 tons/yr
1.34 tons/yr
ICR and plant visits indicate
these types of facilities were
larger emitters
based on detailed facility data
based on detailed facility data
based on detailed facility data
ICRs
based on discussion with foamer
regarding appropriate
throughput
ICR average
foamer estimate that 10 percent
by volume of total MeCl2 used
as cleaner is not recoverable
based on a facility that
provided detailed mold release
agent information
based on a facility that
provided detailed mold release
agent information
site visits, ICRs
based on a facility that
provided detailed adhesive
usage information
based on a facility that
provided detailed adhesive
usage information
Chemical marketing reporter
foamer estimate
vendor quote
vendor quote
90 percent
is waste)
calculated
calculated
of used (remainder
3-4
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add-on control, the factors for incinerators and carbon adsorbers
were used to estimate the total capital investment of the control
technologies in this evaluation, unless detailed information was
provided.
It was assumed that several items (instrumentation,
foundations and support, insulation for ductwork, painting,
engineering, construction and field expenses, contractor fees, a
performance test, and a model study) would not be included in the
total capital investment, unless specific costs for these items
were provided by the vendor. Therefore, the total capital
investment was calculated as shown in Table 3-4. For each type
of polyurethane foam emission reduction technology, the
information provided by the vendor(s) was evaluated to determine
which of the items shown in Table 3-4 were included in the
information provided, and to determine which additional items
needed to be estimated.
The calculation of the total annual costs was also based on
the OAQPS manual. Table 3-5 shows the items considered in the
calculation of total annual costs. As with the total capital
investment, other contributions to the total annual costs were
determined based on the information provided by vendors and
foamers.
3.3 REFERENCES FOR CHAPTER 3.0
1. B. Jordan, EPA:BSD, to flexible polyurethane foam producers.
July 30, 1993. Section 114 information collection requests
(ICRs).
2. U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. OAQPS Control Cost Manual, Fourth
Edition. EPA 450/3-90-006. January 1990.
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TABLE 3-4. CONTRIBUTIONS TO TOTAL CAPITAL INVESTMENT
DESCRIPTION Cost Factor
Purchased Equipment Costs (PEC)
Equipment Aa
Sales Tax 0.03*A
Freight 0.05*A
Total PEC B
Direct Installation Costs (DC)
Handling and erection 0.14*B
Electrical 0.04*B
Piping 0.02*B
Total DC 0.20*B
Indirect Installation Costs (IDC)
Start-up 0.02 *B
Contingencies 0.03*B
Total IDC 0.05*B
Total Capital Investment = PEC + DC + IDC
a equipment costs provided by vendor and/or foamer
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TABLE 3-5. CONTRIBUTIONS TO TOTAL ANNUAL COST
Description
Method for Calculation
Direct Costs (DC)
Materials
Utilities
Maintenance materials
Replacement parts
Operating labor
Supervisory labor
Maintenance labor
Waste treatment
Indirect Costs (IDC)
Capital recovery
Overhead
Administrative charges
Recovery Credits (RC)
Total Annual Cost = DC + IDC
provided*
electric use provided
electric cost = $0.04/kw-h
provided
provided
amount provided
labor rate = $20/hr
15 percent of oper. labor
amount provided
labor rate = $20/hr
provided or calculated
7 percent interest rate
equipment life varied, but
default was 10 years
60 percent of all labor
costs
4 percent of total capital
investment
provided or calculated
- RC
provided means information provided by vendor and/or foamer
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4.0 EMISSION REDUCTION TECHNOLOGIES AND COSTS: MOLDED FOAM
In this chapter, the results of information gathering
efforts are presented for molded foam. This discussion is
organized by emission source. A brief description of each
emission source is provided, followed by discussions and
representative facility costs for all emission reduction
technologies applicable to that source.
Information was obtained for emission reduction technologies
for three HAP emission sources at molded facilities. The sources
are (1) mixhead flushing, (2) mold release agents, and
(3) adhesives for foam repair. Each of these sources are
discussed in the following sections. Since the same HAP-based
adhesives are used in slabstock foam fabrication, there is a
section that includes costs of alternative adhesives for both
molded foam repair and slabstock foam fabrication.
4.1 ALTERNATIVES TO HAP MIXHEAD FLUSHES
Methylene chloride (MeCl2) from flushing of low-pressure
mixheads was the largest emission source for flexible molded foam
manufacture. According to the emissions estimates presented in
the ICR's, over 75 percent (203 tons/yr) of the HAP emissions
from molded foam facilities were from this application.1 With
low-pressure mixheads, the chemical streams enter the mixing
chamber at approximately 40 to 100 pounds per square inch (psi),
and are blended by rotating mixer blades before being released or
"shot" into the mold.2 Residual materials can remain in the
chamber, as well as on the blades. This material needs to be
cleaned out, either after every shot, or after several, depending
on the conditions. Flushing is necessary because the residual
froth can harden and clog the mixhead. This residual froth is
also a problem due to the precision required in the volume of the
foam shot.
Several technologies were found to have the capability of
reducing or eliminating this source of HAP emissions for the
molded foam producer. These technologies are described in detail
below and include non-HAP flushes, high-pressure mixheads, self-
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cleaning mixheads, and solvent recovery units. To make the costs
as conservative as possible, it was assumed that no effort is
made to prevent the evaporation of the waste MeCl2 flush at the
representative facility. The portion that does not evaporate
(see Table 3-1) must be disposed of as a hazardous waste.
4.1.1 Non-HAP Mixhead Flushes
Three non-HAP solvent-based flushes were identified and
investigated. The solvents they contain are primarily cyclic
amide, ethyl ester, glutarate ester, and other esters.3'4 One
product's major component is D-limonene, with small amounts of
terpene hydrocarbons.5 The important characteristics of
alternative flushes are that they are quick-drying, quick
cleaning, and non-reactive with the foam raw ingredients.
All three flushes identified are direct replacements for
MeCl2/ meaning that changing to these flushes typically requires
no equipment or operational changes. This is an advantage in
that no additional capital, utility, maintenance, or operational
costs are required. However, the manufacturers discourage the
use of seals and o-rings made of materials such as PVC, neoprene,
and butyl rubber with these non-HAP mixhead flushes.6'7'8
All three solvent-based flushes eliminate HAP emissions, but
the solvents in them are still classified as VOC. However, all
three products have significantly lower evaporation rates, with
maximum vapor pressures of 2 mm mercury (Hg), as compared to
MeCl2(355 mm Hg vapor pressure). Another major advantage is that
all three products are reclaimable and reusable. According to
the vendors, if the solvent is filtered for solids, the non-HAP
flushes can be reused 2 to 5 times, or more. Methylene chloride
can only be reused if it is distilled.9'10'11
There are also savings in disposal costs of the waste
material, as the spent flush from these products is not
classified as a hazardous waste, unlike MeCl2. A foamer using
one of these products estimated that the disposal costs were
approximately $60 for a 55-gallon drum versus $600 for disposal
of a 55-gallon drum of MeCl2.12 A manufacturer of one of these
4-2
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products stated that the disposal cost for a drum of MeCl2 was
$800.13 To be conservative, the disposal costs used in the
representative facility calculation were $800/drum for MeCl2/ and
$60/drum for non-HAP flushes.
The costs of applying this system to the representative
molded plant are presented in Table 4-1. Approximately the same
volume of non-HAP flushes are required as would be necessary with
the use of MeCl2. These non-HAP products are more expensive than
MeCl2 on a volume basis. A 55-gallon drum of MeCl2 costs
approximately $219, while costs of the non-HAP flushes range from
$382 to $1,375 a drum.14'15'16 For representative facility
costs, an average cost of $838 per drum was used. In calculating
the representative facility costs, to be conservative, it was
assumed that the non-HAP products are reused 3 times, meaning
only 45 drums are needed, as compared to 135 drums of MeCl2.
4.1.2 High-Pressure (HP) Mixheads
Low-pressure mixheads can be replaced with high pressure
(HP) mixheads to eliminate HAP emissions. Three manufacturers of
HP mixheads were contacted. HP mixheads dispense the foam at a
higher pressure, typically 1500 to 3000 psi, as compared to
typical low pressure systems at 40 to 100 psi.17'18 These
mixheads have already replaced low-pressure mixheads in many
larger molded foam facilities.
With HP mixheads, the raw materials are fed into the mixing
chamber through two or more opposing nozzles. The nozzles are
sized to produce a sharp pressure drop that causes the liquid
streams to be accelerated so that when they impinge, the streams
are thoroughly mixed. HP mixheads eliminate the need for MeCl2
as a flushing agent, as there is no residual froth left in the
mixhead. HP heads may not be appropriate for manufacturers of
small parts, as the low throughput rate required for these parts
may be too low for the HP system to achieve the necessary mixing.
When a low pressure mixhead is flushed with solvent,
polyurethane in the mixhead is lost. One vendor estimated the
cost of the lost polyurethane to the foam manufacturer to be
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TABLE 4-1. REPRESENTATIVE FACILITY COSTS FOR
NON-HAP MIXHEAD FLUSHES
Capital Investment*
Total Capital Investment $0
Annual Costs
Direct Costs*
Materials6 $8,120
Waste treatment0 $-7,700
Indirect Costs $0
Total Annual Cost $ 420
Emission Reduction*1 (tons/yr) 37.10
Cost Effectiveness ($/ton) $11
a As discussed above, since these products are direct
replacements for MeCl2, there were no additional capital costs
(equipment or installation, nor any additional annual costs
for labor or maintenance) identified.
b Material costs were calculated as follows:
cost of MeCl2: (135 drums @ $219/drum) = $29,590/yr
cost of alternative = (45 drums @ $838/drum) = $37,710/yr
$37,710 - $29,590 = $8,120
c Waste treatment costs were calculated as follows:
MeCl2 treated: 13 drums @ $800/drum = $lo,400/yr
altern. : 45 drums @ $60 = $2,700/yr
2,700 - 10,400 = -7,700
d A small amount of VOC may be emitted due to the use of these
alternatives.
4-4
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$1.00/lb.19 The use of HP mixheads eliminates this cost,
resulting in a cost savings. It was not possible to calculate
this cost on a facility-wide basis without further information.
Replacing low-pressure mixheads with HP heads requires
replacing more than just the mixing heads. It usually requires
new metering pumps and metering controls, to deliver the
chemicals at the higher pressures. The connecting hoses may also
need to be replaced if they are not suitable for handling the
chemicals under the increased pressure.20>21>22
The cost of HP replacement systems ranges from $75,000 to
$200,000, depending on the size of the system, the required
throughput, and the sophistication of the system.23'24'25'26
Based on detailed information from two manufacturers, an average
price of $97,500 per system was used for the representative
facility.27'28 The machines are typically delivered as complete
units, ready for connection. The cost of the systems includes:
- metering pumps, and auxiliary equipment (e.g., pressure
indicators, pressure relief valve)
- high pressure filter on diisocyanate feed line between the
metering unit and mixhead
- HP mixhead
- hydraulic manifold
- day-tank assembly
- a stored program controlled system with a control desk
It is assumed that there are no changes in energy requirements,
as the vendor stated that the new pumps required for the
increased pressure would not cause a significant increase in the
amount of energy used.29 There are increased maintenance costs
involved in using a HP mixhead versus a low pressure mixhead.
Because of the very high pressures involved, there is
considerable wear on the injection components. One foamer
indicated that the increased maintenance cost is about $10,000
per year for each mixhead, as compared to a low-pressure
mixhead.30 A small cost savings would be seen, as only a small
4-5
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amount of polyurethane material is lost when using this type of
mixhead versus a low pressure mixhead. However, this cost
savings was not included for the representative facility. The
costs of applying this system to the representative molded plant
are presented in Table 4-2.
4.1.3 "Self-Cleaning" Mixhead
Another alternative to HAP mixhead flushing is a self-
cleaning tapered-screw mixhead. The mixhead uses a tapered
mixing screw in a tapered chamber. The screw rotates rapidly to
provide thorough mixing of the raw materials. For cleaning, the
screw moves forward again, at a faster rate, and removes the
residue from the mixing chamber.31
This technology is only applicable for molded systems
manufacturing small parts.32 The throughput for this mixhead
ranges from 2 to 16 Ib/min, which is in the lowest range for
manufacturers of non-automotive seating foam parts. However,
for most material systems, HP mixheads would normally be the
preferred technology for throughputs above approximately
9 Ib/min.33 Consequently, the self cleaning mechanical mixhead
is most applicable at the lower half of the throughput range.34
The vendor did state that there is at least one flexible foam
molder using this technology in New York; however, the EPA was
unable to confirm this information.35 The ICRs did not identify
any flexible molded foam producer using or investigating the
self-cleaning mixhead technology.
The cost of this equipment, new, is approximately $100,000.
The cost of a conversion kit, which only includes the new mixhead
and the drive system, is approximately $35,000. Modifications
would need to be made to the existing metering and control
systems.36>37
The costs of applying this system to the representative
molded plant are presented in Table 4-3. A small cost savings
would be seen, as only a small amount of polyurethane material is
lost when using this type of mixhead, as opposed to a low
pressure mixhead. However, this cost was not included for the
representative facility. No increases in operating costs were
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TABLE 4-2. REPRESENTATIVE FACILITY COSTS FOR HIGH PRESSURE
MIXHEADS
Capital Investment
Purchased equipment costs4 $315,900
Direct installation costsb $63,180
Indirect installation costs0 $15,795
Total Capital Investment $394,875
Annual Costs
Direct Costs'1 $0
Maintenance6 $30,000
Materialsf $-29,590
Waste treatment* $-10,400
Indirect Costs
Capital Recovery11 $56,230
Administrative Charges1 $15,795
Total Annual Cost $62,035
Emission Reduction (tons/yr) 37.1
Cost Effectiveness ($/ton) $1,672
a $97,500 * 3 = $292,500
292,500 * [292,500 * (0.03 tax + 0.05 freight)] = $315,900
b $315,900 * (0.14 hardware and erection +0.04 electrical +0.02
piping)= $63,180
0 $315,900 * (0.02 start-up +0.03 contingency) = $15,795
d There were no additional annual costs for labor identified.
e $10,000 * 3 = $30,000
f This technology eliminates any need for MeCl2, so there is a
material cost savings of $29,590
8 This technology eliminates any need for MeCl2, so there is a
waste treatment savings of $10,400/yr
h $394,875 * 0.1424 (7% for 10 yrs) = $56,230
1 $394,875 * 0.04 = $15,795
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TABLE 4-3. REPRESENTATIVE FACILITY COSTS FOR SELF-CLEANING
MIXHEADS
Capital Investment
Purchased equipment costsa $108,450
Direct installation costsb $21,690
indirect installation costs0 $5,423
Total Capital Investment $135,563
Annual Costs
Direct Costsd
Materials6 $-29,590
Waste treatmentf $-10,400
Indirect Costs
Capital Recoveryg $19,304
Administrative charges11 $5,423
Total Annual Cost $-15,263
Emission Reduction (tons/yr) 37.1
Cost Effectiveness ($/ton) $-411
a $35,000 * 3 = $105,000
105,000 + [105,000 * (0.03 tax)] + $300 freight = $108,450
(Freight cost taken from Klockner-Desman letter, January 5,
1995.
b $108,450 * (0.05 hardware and erection + 0.13 electrical + 0.02
piping)= $21,690
c $108,450 * (0.02 start-up +0.03 contingency) = $5,423
d There were no additional annual costs for labor or maintenance
identified.
e This technology eliminates any need for MeCl2, so there is a
savings of $29,590
f This technology eliminates any need for MeCl2, so there is a
waste treatment savings of $10,400
* $135,563 * 0.1424 (7% for 10 yrs) = $19,304
h $135,563 * 0.04 = $5,423
4-8
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identified. There were no significant operational, maintenance,
or utility usage differences identified by the vendor.
4.1.4 Solvent Recovery Systems
Two facilities were contacted that had solvent recovery
systems in place.38'39 In both systems, the HAP flush is
captured in a 55-gallon drum at each line. The drums are then
taken to a reclamation room, and the flush is pumped into a 2000
to 2500-pound tote. This tote is placed in a solvent reclamation
unit, which is heated to between 210° and 240° Fahrenheit (F) .
The solvent vapors are flashed off and go to a condenser where
they cool and are collected for re-use. The solids from the
still, containing scrap foam and other contaminants, are
collected for disposal.40 Both systems had a recovery rate of
about 70 to 80 percent. The cost of the still system ranges
between $20,000 and $40,000.41>42
One of the systems had an additional step to reduce
emissions at the capture area.43 The three molded lines that
use solvent flush are equipped with a "closed-loop system" for
capturing the MeCl2 vapors from the area around the 55-gallon
drum that is used to capture the flush. This system consists of
a fan that draws the vapors generated in the flush area through a
carbon filter, which captures the solvent vapors before the air
is released to the atmosphere. The cost for this system is
between $500 and $2000 per line. The carbon filter needs to be
replaced approximately once a month at an estimated cost of $100
to $200."
Table 4-4 presents the estimated representative facility
costs. The capital costs used were $30,000 for the still system
and $1,000 per line for the recovery system. One foam
manufacturer stated that it would take an additional 2 hours per
day to load and unload the system.45 A carbon disposal cost of
$150 per month was used.46 While there would be increased
utility and maintenance costs, sufficient information was not
available to allow for a reasonable estimate of these costs. One
foamer indicated that the cost of the disposable bags used to
hold the solvent flush waste and to transport these bags to the
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TABLE 4-4. REPRESENTATIVE FACILITY COSTS FOR SOLVENT RECOVERY
SYSTEMS
Capital Investment
Purchased equipment costs* $35,640
Direct installation costsb $7,128
indirect installation costsc $1,782
Total Capital Investment $44,550
Annual Costs
Direct Costs
Materials'1 $-22,193
Utilities6
Maintenance materials6
Replacement parts6 insufficient information
. , to estimate
Maintenance labor
Operating laborf $9,600
Supervisory labors $1,440
Waste treatment11 $-6,000
Indirect Costs
Capital Recovery1 $6,344
Overheadj 6,624
Administrative chargesk $1,782
Total Annual Cost $-2,403
Emission Reduction (tons/yr)1 27.8
Cost Effectiveness ($/ton) $-86
a [$30,000 + ($1,000 * 3)] = 33,000
33,000 + [33,000 * (0.03 tax + 0.05 freight)] = $35,640
b $35,640 * (0.14 hardware and erection + 0.04 electrical + 0.02
piping)= $7,128
c $35,640 * (0.02 start-up + 0.03 contingency) = $1,782
d Savings of 75 percent of MeCl2 costs due to recovery: $29,590
* 0.75 = $22,193
6 It is assumed that there would be additional utility and
maintenance costs, but sufficient information was not provided
to allow an estimation of these costs.
f 2 hours/day * 240 days/yr * $20/hr = $9,600
8 $9,600 * 0.15 = $1,440
h Savings of 75 percent of MeCl2 disposal costs due to recovery:
$10,400 * 0.75 = $7,800. Added cost of carbon disposal =
$150/month * 12 months = $1,800.
Total disposal costs = $1,800 - $7,800 = $-6,000
1 $44,550 * 0.1424 (7% for 10 years) = $6,344
j ($9,600 + $1,440) * 0.60 = $6,624
k $44,550 * 0.04 = $1,782
1 37.1 tons * 0.75 = 27.8 tons/yr
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dumpster was approximately $30/dozen.47 Because it was not
possible to determine the consumption rate of these bags, this
cost was not included in the representative facility
calculations. An MeCl2 recovery efficiency of 75 percent was
used.
4.2 ALTERNATIVE MOLD RELEASE AGENTS
According to the emissions estimates presented in the ICRs,
approximately 3 percent (7.9 tons) of the HAP emissions from
molded foam facilities were due to the evaporation of the carrier
solvent from mold release agents.48 Mold release agents are
sprayed on the mold surface(s) before the foam mixture is poured
into the mold to prevent adhesion and create a smooth surface.
Traditional mold release agents consist of a resin or wax in a
solvent carrier. This solvent carrier is often composed of MeCl2
or 1,1,1-trichloroethane (methyl chloroform). The carrier
evaporates, leaving the resin, which prevents the foam from
sticking to the mold. Alternatives being used or investigated by
the industry include water-based agents, naphtha-based agents,
and reduced-VOC solvent agents. The following sections discuss
these three options.
4.2.1 Reduced-VOC Mold Release Agents
The reduced-VOC mold release agents are produced through
high-solids, solvent-based formulations. The advantage of these
agents over traditional HAP-based agents is a reduction in VOC
emissions of up to 80 percent. The one vendor that was contacted
stated that the reduced VOC carrier solvent used was a non-HAP;
however, it was unclear if the solvents used in most reduced-VOC
mold release agent formulations are HAP.49 The vendor stated
that most users have seen a reduction in mold release agent
consumption of 20 to 50 percent after switching to the
reduced-VOC release agents.50 No equipment changes are
necessary in switching to this type of release agent, and no
significant operator training or mold temperature changes are
necessary.
The representative facility costs are presented in Table
4-5. The price per gallon of this reduced-VOC agent is over twice
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TABLE 4-5. REPRESENTATIVE FACILITY COSTS FOR REDUCED-VOC MOLD
RELEASE AGENTS
Capital Investment*
Total Capital Investment $0
Annual Costs
Direct Costs*
Materials1* $2,077
Indirect Costs $0
Total Annual Cost $2,077
Emission Reduction0 (tons/yr) 4.6
Cost Effectiveness ($/ton) $452
a As discussed above, since these products are direct
replacements for HAP-based release agents, there were no
additional capital costs (equipment or installation)
identified. No additional annual costs for labor or
maintenance were identified.
b Material costs were calculated as follows:
HAP-based: $4.82/gal * 1688 gal = $8,136
Reduced-VOC: $9.31/gal * 1097 gal = $10,213
$10,213 - $8,136 = $2077/yr
c HAP emissions will be replaced by VOC emissions, but at a rate
of 40% of the HAP emissions (1.8 tons/yr VOC emissions)
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as much as that for traditional solvent-based agents, at $9.31
per gallon.51'52 However, much of this material cost is offset
by the reduction in usage.53 For the representative facility,
an average usage reduction of 35 percent was assumed, and a HAP
emission reduction of 100 percent was used.
4.2.2 Naphtha-based Release Agents
Naphtha-based release agents are composed of resins in a
hydrocarbon naphtha carrier solvent. Naphtha typically comprises
at least 90 percent of the mold release agent.54 While naphtha
is not a HAP, it is listed as a VOC.
The cost of naphtha-based release agents is approximately
$0.65 per pound, or $4.16 per gallon.55 Foam manufacturers have
found that a smaller amount of mold release agent is needed when
naphtha-based agents are substituted for HAP-based agents.56
Because it was not possible to quantify this reduction, a
conservative estimate of a 5 percent reduction in usage was
chosen for the calculation of the representative facility costs
shown in Table 4-6. There were no necessary process or equipment
changes identified, nor any increase in maintenance or labor
costs.
4.2.3 Water-based release agents
Using water-based mold release agents is a more complicated
substitution than using naphtha or reduced-VOC solvent based
agents.57'58 However, unlike the other two alternatives, water-
based mold release agents totally eliminate organic emissions.
All water-based mold release agent manufacturers spoken to
emphasized that selection of a water-based release agent is
customer-specific, and that the correct selection can require
time and several trials before the appropriate product is
found.59'60 The developmental procedures can be costly in time,
as well as in scrap foam, during the transitional period.61
However, the up-front developmental procedures may eventually
result in additional benefits and cost reductions.
There are a few production changes that need to be made when
converting from a solvent-based to a water-based agent. Water-
based release agents are more application-sensitive than the
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TABLE 4-6. REPRESENTATIVE FACILITY COSTS FOR NAPHTHA-BASED
MOLD RELEASE AGENTS
Capital Investment8
Total Capital Investment $0
Annual Costs
Direct Costs*
Materials'5 $-1,463
Indirect Costs $0
Total Annual Cost $-1,463
Emission Reduction6 (tons/yr) 4.6
Cost Effectiveness ($/ton) $-318
a As discussed above, since these products are direct
replacements for HAP-based release agents, there were no
additional capital costs (equipment or installation)
identified. No additional annual costs for labor or
maintenance were identified.
b Material costs were calculated as follows:
HAP-based: $4.82/gal * 1688 gal = $8,136
Naphtha-based: $4.16/gal * 1604 gal = $6,673
$6,673 - $8,136 = savings of $l,463/yr
c HAP emissions will be replaced by an approximately equal level
of VOC emissions.
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solvent-based agents, so some spray retraining may be necessary.
However, the spray retraining can benefit the foam producer by
giving the producer an opportunity to teach the production line
operators to reduce use levels, resulting in further cost
reductions.62 Mold temperature changes may also be necessary
when switching to some water-based agents, due to the higher
evaporation temperature of water. There are no equipment changes
necessary, except that some manufacturers recommend High Volume
Low Pressure (HVLP) sprayers for use with the water-based agents,
due to the need for increased application sensitivity.63'64
The major disadvantages of water-based agents are the
increased drying time and a development period which may be
extensive. Also, foams produced using water-based mold release
agents have a less porous surface than those poured with
conventional release agents, which can be a disadvantage when
adhering fabrics to the foam.65
The cost of the water-based agents is higher per gallon than
HAP-based agents, at $6.00 per gallon.66 The usage of water-
based release agents, as compared to HAP-based agents, seemed to
vary from case to case, so it was assumed that the usage was
equivalent for the representative facility costs shown in
Table 4-7.
4.3 ALTERNATIVE ADHESIVES
HAP-based adhesives are used in both slabstock and molded
foam facilities. In slabstock facilities, spray adhesives are
used to glue fabric-to-foam, or foam-to-foam. In the slabstock
industry, only about 40 percent of the fabrication is done
"in-house," and not all fabrication involves gluing.67
Fabrication covers the broad range of die cut parts, cut parts,
as well as glued parts. Adhesives used for fabrication accounted
for 1,382 tons, or 7.5 percent of the total HAP emissions from
slabstock facilities. Normally, these adhesives are
approximately 20 to 40 percent solids, while the remainder
consists of a solvent carrier, such as methyl chloroform or
MeCl2.
The main use of adhesives in molded foam facilities is for
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TABLE 4-7. REPRESENTATIVE FACILITY COSTS FOR WATER-BASED MOLD
RELEASE AGENTS
Capital Investment*
Total Capital Investment $0
Annual Costs
Direct Costs*
Materials1* $1,992
Indirect Costs $0
Total Annual Cost $1,992
Emission Reduction (tons/yr) 4.6
Cost Effectiveness ($/ton) $433
* As discussed above, since these products are direct
replacements for HAP-based release agents, there were no
capital (equipment or installation) costs identified. There
were no additional annual costs for labor or maintenance
identified. No costs could be estimated for development and
training, but there will be costs for these items.
b Material costs were calculated as follows:
HAP-based: $4.82/gal * 1688 gal = $8,136
Water-based: $6.0/gal * 1688 gal = $10,128
$10,128 - $8,136 = cost $l,992/yr
4-16
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the repair of voids and tears in the molded pieces. There were
26 tons of HAP emissions (less than 10 percent) reported at
molded facilities from this source in the ICR's.68
Three alternatives were identified that eliminate HAP
emissions from the use of adhesives. These are (1) hot-melt
adhesives, (2) water-based adhesives, and (3) Hydrofuse. Each is
discussed in the following sections.
4.3.1 Hot-Melt Adhesives
Hot-melt adhesives are sold as solids that are melted in a
tank system before being used. They are then sprayed on like
solvent-based adhesives. They have a quick drying, or "tack,"
time. This feature has both advantages and disadvantages. The
main advantage is that the quick tack time allows for a faster
production time than many other adhesives. The main disadvantage
is that the adhesive may cease to be sticky before the assembly
is complete. However, the tack time varies between
manufacturers, and some manufacturers produce hot-melts with
expanded tack times. Another problem is the possibility of
operator injury, as the temperature of the adhesive is maintained
above 200° F, which could cause burns.69 An additional problem
is that hot melt adhesives tend to produce hard seams, which are
not acceptable in a soft, flexible foam product.
Hot-melt adhesives do not contain any HAP; however, very
small amounts of low molecular weight hydrocarbons may be emitted
at the application temperatures. There is also a decrease in the
amount of adhesive needed for the same amount of foam.70
Because it was not possible to quantify this reduction, a
conservative estimate of 15 percent reduction was used, based on
information received from vendors.
The costs for using hot-melt adhesives at both the slabstock
and molded foam representative facilities are presented in
Table 4-8. The tanks to melt the adhesives cost approximately
$3,000 per tank, and the hot-melt adhesive costs approximately
$20.30 per gallon.71 There is a small electricity cost for the
glue tanks.72 There were no direct installation costs, as the
equipment does not need any additional erection, wiring, or
4-17
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TABLE 4-8. REPRESENTATIVE FACILITY COSTS FOR HOT-MELT ADHESIVES
Capital Investment
Purchased equipment costs8
Direct installation costs
indirect installation costsb
Total Capital Investment
Annual Costs
Direct Costs6
Materials'1
Utilities6
Indirect Costs
Capital Recovery^
Administrative charges8
Recovery Credits
Total Annual Cost
Emission Reduction11 (tons/yr)
Cost Effectiveness ($/ton)
Slabstock
$19,440
0
$970
$20,410
$93,491
$149
$2,906
$816
$0
$97,362
43
$2,264
Molded
$6,480
0
$340
$6,820
$3,015
$50
$971
$273
$0
$4,309
1.34
$3,216
a $3,000 * 6 = $18,000
18,000 + [18,000 * (0.03 tax + 0.05 freight)] = $19,400
(slabstock)
$3,000 * 2 = $6,000
6,000 + [6,000 *(0.03 tax +0.05 freight)] = $6,480 (molded)
b $19,400 * (0.02 start-up + 0.03 contingency) = $970 (slabstock)
$6,804 * (0.02 start-up + 0.03 contingency) = $340 (molded)
0 There were no additional annual costs for labor or maintenance
identified.
d HAP-based: 10,679 gal @ $8.50/g = $90,772 (slabstock)
Hot-melt: 9,077 gal @ $20.30/g = $184,263 (slabstock)
HAP-based: 345 gal @ $8.50/g = $2,933 (molded)
Hot-melt: 293 gal @ $20.30/g = $5,948 (molded)
6 1725 watts/1000 = 0.1725 kw * 16 hr = 2.76 kw-h/d
2.76 kw-h/d * 225 d/yr =621 kw-h/yr *$0.04/kw-h =
$24.84/yr/spray station
f $20,410 * 0.1424 (7% for 10 yrs) = $2,906 (slabstock)
$6,820 * 0.1424 (7% for 10 yrs) = $971 (molded)
8 $20,410 * 0.04 = $816 (slabstock)
$6,820 * 0.04 = $273 (molded)
h A small amount of VOC may be emitted due to the use of this
alternative
4-18
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piping. There were no additional maintenance or labor costs
identified.
4.3.2 Water-Based Adhesives
The largest advantage of water-based adhesives is that all
HAP have been replaced by water, and there is a complete
elimination of organic emissions. A major drawback is the slower
drying times of these adhesives, which may create a need for
larger drying areas. To solve this problem, some fabrication
operations use an additional heat source to speed up the
evaporation of the water, which would increase the utility costs,
due to operation of the heat lamps. However, there are no other
equipment or operational changes necessary to replace HAP-based
adhesives with water-based. Only one vendor provided a cost per
gallon for water-based adhesives. He stated that the average
cost is approximately $7.00 per gallon.73
The costs of this alternative for the representative
slabstock and molded facilities are presented in Table 4-9. The
increased utilities cost was not determined, but it is expected
to be minimal. The usage was found to be the same for water-
based adhesives as for HAP-based. It was assumed that no
additional heat source was used at the representative facility,
due to the unavailability of information on the use of heat
sources for this application.
4.3.3 Hydrofuse
Another water-based alternative to spray-applied
solvent-based adhesives is a product called Hydrofuse. Hydrofuse
is a two component, water-based adhesive that allows immediate
contact bonding without the need for drying. The two-components,
a water-based latex adhesive, and a mild citric acid solution,
are externally co-sprayed causing the adhesive to immediately
coagulate.74
This process does require process and equipment changes.
Equipment alterations will include changing to new spray guns,
and assuring that all equipment parts that come in contact with
the adhesive are stainless steel or plastic. Process
considerations include operator training in the use of a two-
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TABLE 4-9. REPRESENTATIVE FACILITY COSTS FOR WATER-BASED
ADHESIVES
Capital Investment Slabstock Molded
Total Capital Investment* $0 $0
Annual Costs*
Direct Costs
Materials1* $-15,699 $-508
Utilities6
Indirect Costs'1
Total Annual Cost $-15,699 $-508
Emission Reduction (tons/yr) 43 1.34
Cost Effectiveness ($/ton) $-365 $-379
a As discussed above, since these products are direct
replacements for HAP-based adhesives, there were no capital
costs (equipment or installation), identified. There were no
additional annual costs for labor, maintenance, or waste
treatment identified.
b HAP-based: $8.50/g * 10,679g = $90,772 (slabstock)
Water-based: $7.03/g * 10,679g = $75,073 (slabstock)
75,073 - 90,772 = -15,699 (slabstock)
HAP-based: $8.50/g * 345g = $2,933 (molded)
Water-based: $7.03/g * 345g = $2,425 (molded)
2,425 - 2,933 = -508 (molded)
c Unable to quantify
d No indirect costs identified
4-20
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component adhesive, and in application rates. Another special
requirement for this adhesive is that one of the two surfaces to
be adhered must be porous. A significant advantage of this
product is that there is little or no penetration of the surface
to which it is applied, and it dries almost instantly.75
The costs for using Hydrofuse at both the slabstock and
molded foam representative facilities are presented in Table 4-
10. There were no direct installation costs, as the equipment
does not need any additional erection, wiring, or piping. There
were no additional maintenance or labor costs identified. The
cost of the spray equipment ranges for $2,000 to $3,000 ($2,500
used for analysis) and the adhesive's material cost is
approximately 6 percent less than HAP-based adhesives.76 The
usage for hydrofuse is less than for HAP-based adhesives, but the
percentage difference was not quantified.
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TABLE 4-10. REPRESENTATIVE FACILITY COSTS FOR HYDROFUSE ADHESIVE
Capital Investment Slabstock Molded
Purchased equipment costs* $16,200 $5,400
Direct installation costs $0 $0
indirect installation costsb $810 $270
Total Capital Investment $17,010 $5,670
Annual Costs
Direct Costsc
Materials4 $5,446 $176
Utilities6
Indirect Costs
Capital Recoveryf $2,422 $807
Administrative charges8 $680 $227
Total Annual Cost $8,548 $1,210
Emission Reduction (tons/yr) 43 1.34
Cost Effectiveness ($/ton) $199 $903
a $2,500 * 6 = $15,000
15,000 * [15,000 * (0.03 tax + 0.05 freight)] = $16,200
(slabstock)
$2,500 * 2 = $5,000
5,000 * [5,000 * (0.03 tax +0.05 freight)] = $ 5,400
(molded)
b $16,200 * (0.02 start-up +0.03 contingency) = $810 (slabstock)
$5,400 * (0.02 start-up + 0.03 contingency) = $270 (molded)
c There were no additional annual costs for labor or maintenance
identified.
d HAP-based: 10,679 gal @ $8.50/g = $90,772 (slabstock)
Hydrofuse: $90,772 * 0.94 = $85,326 (slabstock)
90,772 - 85,326 = 5,446
HAP-based: 345 gal @ $8.50/g = $2,933 (molded)
Hydrofuse: $2,933 * 0.94 = $2,757
2,933 - 2,757 = 176
e Unable to determine
f $17,010 * 0.1424 (7% for 10 yrs) = $2,422 (slabstock
$5,670 * 0.1424 (7% for 10 yrs) = $807 (molded)
8 $17,010 * 0.04 = $680 (slabstock)
$5,670 * 0.04 = $227 (molded)
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4.4 REFERENCES FOR SECTION 4.0
1. A. Williams, EC/R Inc., to D. Svendsgaard, EPA:ESD:OCG.
February 10, 1995. Non-confidential summary of Flexible
Polyurethane Foam Information Collection Request (ICR) Data.
2. Herrington, R., and K. Hock. Flexible Polvurethane Foams.
Dow Plastics, 1991. p. 5.15.
3. Dynaloy, Inc. Material Safety Data Sheet. Transmitted to
EC/R Inc. via facsimile on April 26, 1994.
4. Huron Technologies, Inc. Material Safety Data Sheet.
Transmitted to EC/R Inc. via facsimile on April 29, 1994.
Cover letter from G. Borgeson, president, Huron Technologies,
Inc. to A. Williams, EC/R Inc.
5. Florida Chemical Co., Inc. Material Safety Data Sheet.
Transmitted via facsimile from Steven Ferdelman, Chem Central,
to A. Williams, EC/R Inc., on April 23, 1994.
6. Reference 3.
7. Reference 4.
8. Reference 5.
9. Reference 3.
10. Reference 4.
11. Reference 5.
12. Telecon: A. Williams, EC/R Inc., to T. Conway, Conway
Industries. April 28, 1994.
13. G. Williams, Nu-Foam Products, Inc., to D. Svendsgaard,
EPA:ESD:OCG. January 9, 1995. Letter transmitting comments
on the cost analysis prepared by EPA.
14. Telecon: A. Williams, EC/R Inc., to P. Esemplare, Dynaloy,
Inc. April 22, 1994.
15. Telecon: A. Williams, EC/R Inc., to C. Borgeson, Huron
Technologies, Inc. April 27, 1994.
16. Telecon: A. Williams, EC/R Inc., to S. Ferdelman, Chem
Central. April 28, 1994.
17. F. Solomon, Miles Hennecke Machinery Corp., to A. Williams,
EC/R Inc. July 12, 1994. Facsimile transmitting price
information on HP mixheads.
4-23
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18. A. Williams, EC/R Inc., to D. Svendsgaard, EPA:ESD:OCG. May
27, 1994. Memorandum discussing information gathered from
manufacturers of HP mixheads.
19. G. Lewis, Klockner Desma Sales and Service, Inc., to D.
Svendsgaard, EPA:ESD:OCG. January 5, 1995. Letter
transmitting comments on the cost analysis prepared by EC/R
Inc.
20. Telecon: A. Williams, EC/R Inc., to M. Pritchard, Admiral
Corp. May 25, 1994.
21. Telecon: A. Williams, EC/R Inc., to F. Solomon, Hennecke
Machinery. May 25, 1994.
22. Telecon: A. Williams, EC/R Inc., to M. Mangold, Foamex, LP.
April 12, 1994.
23. Reference 20.
24. Reference 21.
25. Telecon: A. Williams, EC/R Inc., to R. Hogue, Krauss Maffei
Corp. May 25, 1994.
26. R. Hogue, Krauss-Maffei Corp., to A. Williams, EC/R Inc. June
1, 1994. Letter transmitting cost information .
27. Reference 21.
28. Reference 26.
29. Reference 21.
30. M. Mangold, Foamex, LP, to D. Svendsgaard, EPA:ESD:OCG.
January 10, 1995.
31. Telecon: A. Williams, EC/R Inc., to G. Lewis, Klockner
Ferromatik Desma. May 18, 1994.
32. Reference 31.
33. Reference 22.
34. Reference 19.
35. Reference 31.
36. Reference 31.
37. Telecon: A. Williams, EC/R Inc., to G. Lewis, Klockner
Ferromatik Desma. July 15, 1994.
4-24
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38. Telecon: A. Williams, EC/R Inc., to D. Peck, Renosol Corp.
June 7, 1994.
39. Telecon: A. Williams, EC/R Inc., to S. Smoller, E-A-R
Specialty Corporation. June 10, 1994.
40. Reference 38.
41. Reference 39.
42. Telecon: A. Williams, EC/R Inc., to D. Majewski, Renosol
Corp. June 10, 1994.
43. Reference 42.
44. Reference 42.
45. S. Smoller, E-A-R Specialty Composites, to A. Williams, EC/R
Inc. December 21, 1994. Letter transmitting comments on
EPA's draft cost analysis.
46. Reference 42.
47. S. Smoller, E-A-R Specialty Composites, to D. Svendsgaard,
EPA:ESD:OCG. December 21, 1994. Letter transmitting comments
on EPA's December 9, 1994 draft cost analysis of the
alternatives for reducing HAP emissions in this industry.
48. Reference 1.
49. Telecon: A. Williams, EC/R Inc., to J. Robinson, Air
Products. April 21, 1994.
50. Telecon: A. Williams, EC/R Inc., to J. Robinson, Air
Products. July 11, 1994.
51. Reference 49.
52. Reference 50.
53. Reference 50.
54. Telecon: A. Williams, EC/R Inc., to M. Gromnicki, Swenson
Corp. July 14, 1994.
55. Telecon: A. Williams, EC/R Inc., to C. Borgeson, Huron
Technologies. July 14, 1995.
56. Telecon: A. Williams, EC/R Inc., to D. Majewski, Renosol
Corp. July 19, 1994.
57. Reference 49.
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58. Telecon: A. Williams, EC/R Inc., to C. Asuncion, Air
Products. April 20, 1994.
59. Reference 49.
60. Reference 58.
61. Reference 58.
62. R. Santo, Air Products, to D. Svendsgaard, EPA:ESD:OCG.
January 16, 1995. Letter transmitting comments on EPA's
December 9, 1994 cost analysis of alternatives for reducing
HAP emissions in this industry.
63. Reference 49.
64. Reference 58.
65. Reference 58.
66. R. Santo, Air Products, to D. Svendsgaard, EPA:ESD:OCG.
January 16, 1995. Letter transmitting comments on the product
and cost data of alternatives for reducing or eliminating
HAP's in the manufacture of flexible polyurethane foam, as
determined by EPA.
67. Reference 1.
68. Reference 1.
69. H.B. Fuller Company, Technical Data Sheet on Hot Melt Adhesive
(Product No. HL-6278).
70. Telecon: A. Williams, EC/R Inc., to D. Kehr, H.B. Fuller
Company. June 22, 1994.
71. Reference 70.
72. Telecon: A. Williams, EC/R Inc., to D. Brauen, Nordson Corp.
June 27, 1994.
73. Telecon: A. Williams, EC/R Inc., to M. Lechowicz, Midwest
Industrial Chemical Co. June 22, 1994.
74. H.B. Fuller Company Technical Data Sheet for Hydrofuse
(Product No. WC-0686-A 770). June 22, 1994.
75. Reference 70.
76. Telecon: P. Norwood, EC/R Inc., to A. Abraham, H.B. Fuller
Co. July 28, 1994.
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5.0 EMISSION REDUCTION TECHNOLOGIES AND COSTS: SLABSTOCK FOAM
Information was obtained for emission reduction technologies
for three HAP emission sources at slabstock facilities. These
are (1) auxiliary blowing agent (ABA) usage, (2) equipment
cleaning, and (3) adhesives for fabrication. Emission reduction
technologies for ABA reduction/replacement and equipment cleaning
are discussed in the following sections. Alternative adhesives
for slabstock foam fabrication were discussed in the molded foam
section.
5.1 ALTERNATIVES TO METHYLENE CHLORIDE AS AN ABA
Methylene chloride is the principal ABA used in the
production of slabstock flexible polyurethane foam. The role of
the MeCl2 is simply to volatilize and expand the foam, it does
not directly participate in the polyurethane reaction.
Therefore, all of the MeCl2 that is added eventually is emitted.
The use of MeCl2 as an ABA was the largest emission source of HAP
reported in the ICR's, at over 14,600 tons, accounting for over
79 percent of the total HAP emissions from slabstock
facilities.1
Several alternatives were identified that either reduce or
eliminate the use of MeCl2 as an ABA in the manufacture of
slabstock foam. The technologies identified were the use of
acetone or liquid CO2 as an ABA, foaming in a controlled
environment, forced cooling, and chemical modifications. These
alternatives are discussed in the following sections.
It should be pointed out that slabstock foam grades of
identical density and firmness made by different chemical or
mechanical techniques do not necessarily have the same strength,
durability, or other quality properties. However, the best way to
determine comparability of foam quality properties is through in-
use testing. The EPA's analysis assumes that foam properties are
comparable, unless detailed information was provided that stated
otherwise.
5.1.1 Acetone as an ABA
In response to environmental concerns over the use of MeCl2/
5-1
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Hickory Springs developed and patented a technology in 1992 to
allow the use of acetone as an ABA. One of acetone's biggest
advantages is that it only requires 55 percent (by weight) as
much acetone as MeCl2 to blow the same amount of foam.2 Another
advantage is that acetone typically costs less per pound than
MeCl2. Current estimates of chemical costs for slabstock
manufacturers are $0.20/lb for acetone versus $0.25/lb for
MeCl2.3 This factor, combined with the reduced usage, can result
in large chemical cost savings. The chemical cost savings is
somewhat counteracted by the licensing fee. This licensing fee
operates on a graded scale depending on the amount of acetone
used by the facility. For the first 50,000 pounds of acetone
used, the fee is $0.16 per pound, $0.14/lb for the next 75,000
pounds, and $0.12/lb for any additional acetone. This fee is
subject to change with trends in acetone and MeCl2 costs.4
Because of the high flammability of acetone, it is necessary
to make certain equipment modifications in order to use acetone
as an ABA. The largest costs of switching to acetone from MeCl2
are due to this increased flammability. These modifications
include:
- The foam tunnel needs to be completely enclosed.
- The lighting needs to be explosion-proof.
- The motors that run the conveyor need to be moved
outside the foam tunnel (the cost is in moving the
motors and putting on longer shafts).
Electric bun saws need to be replaced by
explosion-proof saws.
- There must be an auxiliary power generator for the
ventilation fans.
- Air flow in the tunnel area must be increased, due
to an insurance requirement.
Storage tanks for acetone must be fire-rated,
completely diked, and placed away from the other
buildings. This modification is a large part of
the conversion cost.
A low-level metering system may be necessary as
5-2
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some foam formulations only require 1-3 parts per
hundred of acetone, and traditional metering
systems do not go that low.
Hickory Springs estimated the cost of the equipment plus
installation of the above items to be $194,000.5
Acetone is not a HAP, but it is still listed as a VOC. The
EPA has proposed to remove it from the VOC list (59 FR 49877) .
The costs of applying this system to the representative slabstock
plant are presented in Table 5-1. All capital, labor, and
licensing costs were provided by Hickory Springs.6
5.1.2 Liquid CO2 as an ABA
A procedure for using liquid CO2 as the ABA in slabstock
foam manufacture called CarDio™ has been developed by Cannon
USA. There is a full scale unit in operation in Italy, but there
are no plants in the United States using this technology.
However, in four to six months a few facilities are expected to
have CarDio™ installed. The largest benefit of CarDio™ is that
it completely eliminates HAP emissions.7 Another benefit is the
chemical cost savings, as CO2 is less expensive than MeCl2, and
it only requires 33 percent as much CO2 as MeCl2 to produce the
same amount of ABA-blown foam.8
The CarDio™ system operates by adding liquid CO2 to the
polyol stream before the polyol stream is injected into the
mixing head. This generates a rapidly expanding froth
immediately after the pouring nozzle. Cannon developed a special
laydown device to counteract this rapid expansion. This device
controls the expansion phase immediately after the mixing head,
and allows for the depositing of a homogenous pre-expanding and
reacting mixture over the entire section of the fall-plate. The
laydown device's special design allows for a progressive release
of blowing agent in the reacting mass, avoiding local
concentrations of free gas that can cause pinholes or "chimneys"
in the foam.9
The retrofit kit consists of:10
- CO2 metering pump assembly with mass flowmeter
- Polyol/activator booster pump assembly
5-3
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TABLE 5-1. REPRESENTATIVE FACILITY COSTS FOR ACETONE AS AN ABA
Capital Investment
Purchased equipment costs* $161,700
Direct installation costs" $32,300
indirect installation costs*
Total Capital Investment $194,000
Annual Costs
Direct Costs
Materials15 $-90,500
Utilities0 $5,881
Maintenance materials'1 $2,500
Licensing6 $46,700
Maintenance laborf $2,500
Waste treatment $0
Indirect Costs
Capital Recovery8 $27,626
Overhead11 $1,500
Administrative charges' $7,760
Total Annual Cost $3,967
Emission Reduction (tons/yr)j 325
Cost Effectiveness ($/ton) $12
* Hickory Springs estimated a total capital investment of
$194,000. The EPA estimated the cost of purchased equipment at
$161,700, and total installation at $32,300.
b 325 tons MeCl2 * 0.55 = 179 tons/yr acetone (360,000 Ibs) .
360,000 Ibs * $0.2/lb = $72,000 for acetone/yr
325 tons/yr MeCl2 = 650,000 Ibs
650,000 Ibs * $0.25/lb = $162,500 for MeCl2/yr.
$72,000 - $162,500 = $-90,500 (savings)
c 3 fans * 7.5 hp/fan * 8760 hr/yr = 197,100 hp-h/yr
197,100 hp-h/yr * 0.746 kw-hr/hp-h = 147,037 kw-hr/yr
1992 electricity cost/hr = $0.040/kw-h
147,037 kw-h/yr * $.04/kw-h = $5,881/year electricity cost
d quoted by Doug Sullivan, Hickory Springs Manufacturing Co.
e Licensing fee for 360,000 Ib/yr:
50,000 Ib * $0.16 = $8,000
75,000 Ib * $0.14 = $10,500
235,000 Ib * $0.12 = $28,200
total licensing fee = $46,700
f quoted by Doug Sullivan
8 $194,000 * 0.1424 (7% for 10 yrs) = $27,626
h $2,500 * 0.6 = $1,500
) $194,000 * 0.04 = $7,760
J HAP emissions replaced by approximately 180 tons of VOC
emissions.
5-4
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- CO2/polyol premixing unit
- CarDio™ mixing head
- Necessary pipework and valves
- Flushing system
- Laydown device
- Controls
The costs of applying this system to the representative
slabstock plant are presented in Table 5-2 below. The cost of
the retrofit kit for the representative facility is approximately
$350,000, excluding installation.11 The liquid CO2 costs
approximately $0.05 per pound, and the necessary tank can be
rented for $500 per month. It was assumed that all the foam
formulations requiring ABA would be made using this system. The
pouring time was assumed to be the same for CarDio™ as for
Maxfoam™. The increased energy costs, estimated at 100 to
120 KW, are for the electricity to run the booster pump assembly,
and to keep the CO2cool. There were no increased labor or
maintenance costs identified.12
5.1.3 Foaming in a Controlled Environment
The idea that foam expands more under conditions of
decreased atmospheric pressure is not new. Many types of foam
can be manufactured at higher altitudes with little or no ABA.
In other words, when a given foam formulation is processed at
less than atmospheric pressure (i.e., under vacuum), a lower
density and a softer foam will result when compared to the same
foam formulation being processed at atmospheric pressure. This
principle can be applied under standard atmospheric conditions
through enclosure of the foam line, and subsequent reduction of
pressure during foam production. Two systems that control the
atmospheric conditions during foam production were identified:
variable pressure foaming and controlled environment foaming.
Descriptions of these systems follow.
5.1.3.1 Variable Pressure Foaming (VPF)
The VPF system is patented worldwide by Foamex, L.P. The
system involves processing foam in an enclosed chamber under a
controlled pressure. The pressure in the chamber is fixed before
5-5
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TABLE 5-2. REPRESENTATIVE FACILITY COSTS FOR CARDIO™
Capital Investment
Purchased equipment costs* $378,000
Direct installation costsb $75,600
indirect installation costs0 $18,900
Total Capital Investment $472,500
Annual Costs
Direct Costs
Materials'1 $-151,532
Utilities6 $35,040
Carbon dioxide tank rentalf $6,000
Indirect Costs
Capital Recovery8 $67,284
Administrative charges11 $18,900
Total Annual Cost $-24,308
Emission Reduction (tons/yr)1 325
Cost Effectiveness ($/ton) $-75
a $350,000 +[350,000 * (0.03 tax + 0.05 freight)] = $378,000
b $378,000 * (0.14 hardware and erection + 0.04 electrical + 0.02
piping) = $75,600
c $378,000 * (0.02 start-up + 0.03 contingencies) = $18,900
d 325 tons MeCl2 * .33 = 107 tons CO2
107 tons MeCl2 * $102.5/ton = $10,968
325 tons MeCl2/yr = 650,000 Ibs
650,000 Ibs * $0.25/lb = $162,500 for MeCl2/yr
$10,968 - $162,500 = -$151,532
e Additional electricity costs: 100 kw * 8760 hr = 876,000 kw-h
876,000 kw-h * $0.04/kw-h = $35,040/yr
f tank rental $500/month
8 $472,500 * 0.1424 (7% for 10 yrs) = $67,284
h $472,500 * 0.04 = $18,900
' HAP emission reduction replaced by around 108 tons/yr of CO2
5-6
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foaming and remains constant during the foaming operation. The
mixhead is outside the chamber, and the chemicals are pumped into
the chamber, into a trough, and onto the foam machine
fall-plates. The enclosed chamber is fitted with a fan which
evacuates the vapors generated during the reaction and pumps them
through carbon bed absorbers. When the desired length of foam is
produced, an automatic cut-off saw cuts the bun. This bun is
then passed into a second airlock chamber, which is at the same
pressure as the foaming chamber. This airlock chamber is fitted
with a second fan and carbon bed absorber. Once the cut bun has
completely entered the airlock system, the airlock is closed from
the foaming chamber. This chamber is then opened to the
atmosphere, and the bun is removed and transported to a storage
rack. During this time, foam production is continuing in the
first chamber. In the United States, Foamex has one VPF facility
in full-scale operation, and a few others are being installed.
The main procedural advantages over a conventional Maxfoam
line are that the system is fully automated, and the pressure can
be adjusted and kept consistent from run to run. This automation
results in products with density and hardness properties that are
easily reproducible. Variable pressure foaming allows for the
total elimination of ABAs, with no reduction in quality reported.
In addition, the carbon absorbers in the foaming and airlock
chambers can be expected to practically eliminate the toluene
diisocyanate (TDI) emissions (5 tons/yr reported by industry in
ICRs) from the foaming process.13
The conversion of an existing facility to VPF will involve
the installation of a new foaming chamber, revisions to the
existing line, and an extended shutdown period. Cost information
for VPF was obtained directly from Foamex.14 The total capital
investment for conversion of a Maxfoam line to VPF was estimated
at between $4.0 and $5.0 million dollars ($4.5 million was used
for the representative facility). This estimate included
installation and start-up costs. Foamex indicated that the
annual operating costs are estimated to be 35 percent higher than
a conventional Maxfoam line. However, this is offset somewhat by
5-7
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a savings in chemical costs due to the elimination of the need
for MeCl2. For the representative facility cost calculations,
the annual operating costs of the facility ($2,700,000) were
increased by 35 percent for an incremental increase of
$945,000.15 This was assumed to include all direct and indirect
annual costs except capital recovery (minus the savings from
MeCl2) .
The costs of applying this system to the representative
slabstock plant are presented in Table 5-3.
5.1.3.2 Controlled Environment Foaming (CEF)
FOAM ONE company has developed and patented a polyurethane
foam manufacturing process, which is called Controlled
Environment Foaming (CEF). The CEF process is a discrete block
production method which uses a containment vessel to control the
pressure and temperature during foaming.
The system consists of two molds (as large as 10 feet long
by 9 feet wide by around 4 feet tall). One mold is inside a
pressure-controlled containment vessel, and the other is outside
this vessel. During production, foam is poured into the mold
inside the containment vessel, which is lined with a flexible
polyethylene film liner. The foam reaction is allowed to take
place under the controlled conditions of the containment vessel.
While the foaming is occurring in the mold in the containment
vessel, the finished block in the other mold is removed, and the
mold is prepared for production of the next block. This
operation allows the production of up to 10 blocks per hour,
which is equivalent to around 2 linear feet per minute.16
In addition to the complete elimination of ABA, there are
other advantages to the CEF system. Since the blocks are
prepared in heated molds, the finished block has a perfectly flat
top and a very thin skin, thus maximizing foam yield. The
process is under complete computer control, ensuring exact
duplication of products. In addition, TDI emissions from the
foaming reaction are vented through a carbon bed, thus
practically eliminating TDI emissions.17
While there are low energy requirements and low maintenance
5-8
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TABLE 5-3. REPRESENTATIVE FACILITY COSTS FOR VARIABLE PRESSURE
FOAMING
Total Capital Investment1 $4,500,000
Annual Costs
Increase in annual operating $945,000
costsb
Materials0 $-162,500
Capital Recovery*1 $640,800
Total Annual Cost $1,423,300
Emission Reduction (tons/yr) 325
Cost Effectiveness ($/ton) $4,379
a Provided by Foamex. Assumed to include all direct and indirect
installation costs.
b $2,700,000 (operating costs for representative facility) * 0.35
= $945,000. This 35 percent factor is assumed to include
utilities, maintenance items, labor, operating labor, overhead,
and administrative charges.
c 325 tons MeCl2 * 2000 Ibs/ton * $0.25/lb = $162,500
d $4,500,000 * 0.1424 (7% for 10 yrs) = $640,800
5-9
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expenses, the production rate is considerably slower than a
traditional Maxfoam line.18 Therefore, it would take longer to
make the same amount of foam on a CEF machine. A possible
approach is to produce only the foams requiring ABA on a CEF
machine, while continuing to produce other foams on a Maxfoam
machine. For the representative facility cost calculations, it
was assumed that the 6,760 tons of foam produced with an ABA
would be produced on the CEF machine, and that the 740 tons that
did not require ABA would continue to be produced on a Maxfoam
machine. It was calculated that the representative slabstock
plant would need to operate 16 hours/day using the CEF system to
produce the same amount of formerly ABA-blown foam.
The costs of applying this system to the representative
slabstock facility are presented in Table 5-4. The estimated
cost of the CEF equipment provided by the vendor was $250,000.
In the annual cost calculations, it was assumed that 2 additional
operators were needed, and that the energy requirements were
approximately equal to a Maxfoam line.19 It is assumed that any
additional maintenance costs for the CEF system would be offset
by the reduced maintenance on the Maxfoam line due to the
reduction in its use.
5.1.4 Forced-Cooling
The two primary functions of an ABA are to reduce the
density of the foam and to provide cooling effects. Increasing
the amount of water in the formulation will reduce the foam
density, but increases the exothermicity of the reaction, which
can lead to bun scorching or even auto-ignition (even well after
the bun exits the foam tunnel.) The cooling of the bun by
mechanical means can eliminate this potentially dangerous
situation, while allowing the production of low density foams.
Information was obtained and reviewed on two different
patented types of forced-cooling techniques that are in
full-scale operation: Enviro-Cure® by Grain Industries and
Rapid-Cure® by General Foam. The EPA is also aware of other
companies experimenting with similar forced cooling processes.
Since the Enviro-Cure® technology is fully operational at several
5-10
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TABLE 5-4. REPRESENTATIVE FACILITY COSTS FOR CONTROLLED
ENVIRONMENT FOAMING
Capital Investment
Purchased equipment costsa $270,000
Direct installation costsb $54,000
indirect installation costs0 $13,500
Total Capital Investment $337,500
Annual Costs
Direct Costs'1
Materials6 $-162,500
Operating laborf $144,000
Supervisory labor8 $21,600
Utilities11 $12,960
Indirect Costs
Capital Recovery1 $48,060
Administrative charges' $13,500
Total Annual Cost $77,620
Emission Reduction (tons/yr) 325
Cost Effectiveness ($/ton) $239
a $250,000 + [250,000 * (0.03 tax + 0.05 freight)] = $270,000
b $270,000 * (0.14 hardware and erection +0.04 electrical +
0.02 piping) = $54,000
c $270,000 * (0.02 start-up + 0.03 contingencies) = $13,500
d Any additional maintenance costs for the CEF system were
assumed to be offset by the reduced maintenance on the Maxfoam
line due to the reduction in its use
e Savings from the elimination of methylene chloride as ABA
f 2 operators * 16 hrs/day * 225 days/yr * $20/hr = $144,000/yr
8 $144,000 * 0.15 = $21,600/yr
h Additional electricity costs: 120 kw * 12 hr/day * 225 days/yr
= 324,000 kw-h/yr
324,000 kw-h * $0.04/kw-h = $12,960/yr
' $337,500 * 0.1424 (7 percent for 10 years) = $48,060
j $337,500 * 0.04 = $13,500
5-11
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facilities across the United States, the following discussion
focuses on this system.
Most of the Enviro-Cure® systems in operation in the United
States are installed on Vertifoam® lines. Vertifoam® is a
vertical, rather than horizontal foam line.20 Grain is the only
company currently using this technology in the United States.
Grain has also retrofit a traditional Maxfoam system with Enviro-
Cure®. This type of retrofit is described in the following
section, but the general Enviro-Cure® principle is applicable to
the Vertifoam® system as well.
The Maxfoam Enviro-Cure® system is an enclosure with an
associated conveyor system, which is put in place after the
traditional slabstock pouring line. The cut blocks from the
Maxfoam machine are transferred to the unit, where a special
multi-slat conveyor system transports the block through the
cooling enclosure.21 There is a slight delay before the foam
enters the enclosure to allow the block to stabilize prior to
cooling. Controlled air is passed through the block by means of
a vacuum process after the blocks are inside the enclosure. The
vacuum process cools the blocks by convection and conduction.22
The heat transfer to the cooling process air is handled by
exhausting some air to the atmosphere, and by recirculating some
back through the Enviro-Cure® process. Airflow is controlled
over the whole length of the block to ensure a consistent flow
through the block for even cooling. This air flow consistency
results in a foam bun that is more uniform, meaning that the
properties are more consistent between the outer portion of the
bun and the core.23
There are some differences in the forced cooling systems.
Enviro-Cure® is limited to producing short blocks. Rapid-Cure®
can be used on line to produce continuous blocks, or off-line to
produce blocks limited to the length of the off-line conveyor.
The basis for choosing one system over the other depends at least
partly on the type of business in a specific plant. General Foam
states that the projected capital costs for Rapid Cure® are less
than for Enviro-Cure®, varying mainly with the size of carbon bed
5-12
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used, which in turn depends on production rates and amounts.24
Enviro-Cure® provides no exhaust purification.
There are also drawbacks to the use of forced cooling
technology. A complete range of foam grades can be produced
using forced cooling, but it is generally agreed by industry
representatives that the quality of the some of the lower-
density, soft foam grades is not acceptable in the United States
foam market. Chemical alternatives can be used in connection
with forced cooling to improve foam quality. However, even with
this combination of technologies, the complete elimination of
ABAs is probably not possible without a degradation in foam
quality for certain grades.
The cost information used for the representative facility
was obtained from a paper written by Cannon-Viking, the
manufacturers of the Enviro-Cure® machine.25 The cost of the
Enviro-Cure® system will depend upon the layout of the facility,
but is in the region of 1 to 2.2 million dollars for a complete
Maxfoam conversion.26 A cost of $2 million was used for the
representative facility. This 2 million dollars included all
direct and indirect installation costs. EPA assumed that all the
foam requiring ABA would be made using the Enviro-Cure® system,
so there would also be material cost savings from the elimination
of MeCl2. However, the MeCl2 savings will be offset by increased
formulation costs in many cases. To maintain equal density in
the absence of MeCl2, additional water is used, which requires
the use of more TDI. The need for additional TDI is reduced
somewhat by either using a lower TDI index, or by adding other
additives to maintain the lower IFD associated with the use of
MeCl2.27 These additives are discussed in the next section of
this report. An industry representative indicated that analysis
has indicated that the increased formulation costs were
approximately equal to the savings in MeCl2 cost.28
As mentioned previously, the process is patented by Grain,
and its use will entail a licensing fee of 1.5 percent of the raw
material costs for all Enviro-Cured foams. The costs for the
representative facility are presented in Table 5-5.
5-13
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TABLE 5-5. REPRESENTATIVE FACILITY COSTS FOR ENVIRO-CURE®
Capital Investment
Purchased equipment costs8 $2,000,000
Total Capital Investment $2,000,000
Annual Costs
Direct Costsb $0
Utilities0 $18,400
Licensing Feed $146,756
Indirect Costs
Capital Recovery6 $284,800
Administrative chargesf $80,000
Total Annual Cost $529,956
Emission Reduction (tons/yr) 325
Cost Effectiveness ($/ton) $1,631
a Includes direct and indirect installation costs
b There were no additional labor or maintenance costs identified
c Based on Enviro-Cure® paper entitled "Cannon Enviro-Cure®
Equipment Applied to the Vertifoam and Maxfoam Processes."
d 0.015 * $9,783,743 = $ 146,756
e $2,000,000 * 0.1424 (7% at 10 yrs) = $284,800
f $2,000,000 * 0.04 = $80,000
5-14
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5.1.5 Chemical Modifications
Chemical modifications are demonstrated methods of reducing
ABA usage. The types of chemical modifications included in this
analysis can be separated into two groups: chemical additives,
and alternative or "soft" polyols. Additives are usually added
to the foam formulation at the mixhead. The alternative polyols
are substituted for a portion of the traditional polyols in the
foam formulations.
Chemical additives and alternative polyols have proven to be
successful in the reduction of the amount of ABA used for foam
softening.29 There are two basic methods by which these
technologies soften the foam. The most common method is by
reducing the TDI index, which reduces the number of diisocyanate
groups available to form urea linkages. One of the additives
studied softens foam by changing the reactivity of the
diisocyanate groups of the TDI isomers so that the resulting
polyurea segments of the foam are altered.30
These chemical modification technologies can allow the
elimination of ABA for foams with densities greater than
1.0 lb/ft3, and IFDs greater than 20 Ibs, although there will
likely be a deterioration in foam properties at densities less
than 1.5 Ibs and IFDs lower than around 25 Ibs. However, the use
of these chemical alternatives for the lower density/lower IFD
foams does allow a reduction in the amount of ABA needed, without
sacrificing foam property quality. The actual amount of
reduction will vary with the combination of density, IFD, and
other desired foam properties, but can be as high as 70 percent.
These technologies have not been as successful in the area
of density reduction. Unlike MeCl2, they do not directly
decrease the density by auxiliary "blowing" of the foam. They
also do not provide the necessary cooling effects to allow
increased water levels. However, as noted above in the section
on forced cooling, the combination of forced cooling and chemical
modification can allow further reduction in the ABA usage for
density reduction.
An advantage of chemical modifications is that their use
5-15
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does not change the production method for slabstock foam.
Capital improvements may be necessary, including a new storage
tank and associated plumbing, and new pump(s) and a metering
system. The specific needs will depend on the existing situation
at each facility. Estimates of purchased equipment costs for
these improvements ranged from $5,000 to $50,000. For the
representative facility costs, it was assumed that the following
improvements are necessary:
Storage tank $ 5,000
Plumbing $ 2,000
Pump $ 4,000
Metering system $12.500
TOTAL $23,500
The costs are based on information provided by the PFA-member
chemical suppliers.31
The annual costs will include the material cost of the
chemical alternative (minus the cost of the MeCl2 no longer
needed), and the capital recovery of the necessary improvements.
The chemical costs and ABA reduction potential of these chemical
technologies are different for each foam grade. Grade-specific
information provided by PFA-member chemical suppliers was used.
Table 5-6 compares the standard formulations and the
chemical alternative formulations. Arithmetic averages of the
information provided by the chemical suppliers were used to
calculate the totals in Table 5-6.
The chemical alternatives represented include Dow's
XUS15216.00 polyol, Arco's DP-1022 additive and F-1500 polyol,
OSi's GEOLITE®91 and 201 modifiers, and Goldschmidt's Ortegol®
modifier.
The total representative facility costs for using chemical
alternatives are shown in Table 5-7. Since much of the
information related to chemical alternatives was claimed as
confidential business information (CBI), there is not an
attachment related to this technology.
5.2 EQUIPMENT CLEANERS
Methylene chloride is used as a cleaner to rinse and/or soak
5-16
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-------
TABLE 5-7. REPRESENTATIVE FACILITY COSTS FOR CHEMICAL
MODIFICATIONS
Capital Investment
Purchased equipment costs* $25,380
Direct Installation Costsb $5,076
Indirect Installation Costs0 $1,269
Total Capital Investment $31,725
Annual Costsd
Direct Costs
Materials6 $314,506
Indirect Costs
Capital Recoveryf $4,505
Administrative charges8 $1,265
Total Annual Cost $320,276
Emission Reduction11 (tons/yr) 147
Cost Effectiveness ($/ton) $2,179
a $23,500 + [23,500 * (0.03 tax + 0.05 freight)] = $25,380
b $25,380 * (0.14 handling and erection +0.04 electrical +0.02
piping) = $5,076
c $25,380 * (0.02 start-up + 0.03 contingency) = $1,269
d There are no additional annual costs for operating labor,
maintenance, utilities, or waste treatment.
e $11,115,009 - $10,800,503 = $314,506 (See Table 5-6)
f $31,725 * 0.1424 (7% for 10 years) = $4,518
«$31,725 * 0.04 = $1,269
h 325 tons - 178 tons = 147 tons (see Table 5-6)
5-18
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foam machine parts such as mixheads and foam troughs. This use
resulted in six tons of emissions (less than 1 percent of total
slabstock HAP emissions),32 The two alternatives identified to
eliminate these HAP emissions were steam cleaning and non-HAP
cleaners. To make the costs as conservative as possible, it was
assumed that no effort is made to prevent the evaporation of the
MeCl2 used for cleaning. The portion that does not evaporate
(see Table 3-3) must be disposed of as hazardous waste.
5.2.1 Steam Cleaning
Three flexible polyurethane foam slabstock plants were
identified in the ICR database that use steam to flush hoses,
mixheads, and other pouring equipment. All three identified were
owned by Ohio Decorative Products, and it was indicated that this
is becoming a company-wide practice. The costs of switching
varied between the plants contacted, as one utilized steam
already produced on-site for another function (rebond), while the
other had to purchase a generator specifically for steam
production.33'34 The reacted foam scrap from both operations
was collected and shredded for use in either the on-site rebond
operation, or sent off-site to a rebond operation. For the
facility that already had a source of steam, the conversion cost
was only about $200, which was mostly for hoses.35 The facility
using a gas-fired mobile steam generator estimated their costs to
be between $3,000 and $5,000.36
The use of steam for equipment cleaning may be a cost
effective method of HAP emission reduction. However, no one was
able to provide any estimate of the additional energy costs
needed to generate the steam, the costs of maintenance materials,
labor, and replacement parts, or the amount of additional
operating labor needed. Since the items listed above could make
up a large portion of the total annual costs, and the fact that
no information, or statements that could lead to informed
assumptions, was available, representative facility costs were
not developed for steam cleaning.
5.2.2 Non-HAP Cleaners
There were several alternative cleaners identified that were
5-19
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not HAP-based. The solvents they contain are furanone, cyclic
amide, ethyl ester, other esters, N-Methylepyrrolidone (NMP), and
D-limonene.37'38
All three cleaners identified, Strip-TZ®, Foamflush, and
Dynasolve, are direct replacements for MeCl2, meaning that they
typically require no equipment or operational changes. This is
an advantage as there are no additional utility, maintenance, or
operational costs. However, the manufacturers discourage the use
of seals and o-rings made of certain materials such as PVC,
neoprene, and butyl rubber with non-HAP cleaners.39
All three non-HAP solvent-based cleaners eliminate HAP
emissions, but the solvents they contain may still be classified
as VOC. Like the non-HAP mixhead flushes discussed in the molded
foam section, all three products have low evaporation rates, and
can be reclaimed and reused. There are also savings in disposal
costs of the waste material, as none of the spent cleaner from
these products is classified as a hazardous waste, unlike MeCl2.
The costs of applying these products to the representative
slabstock plant are presented in Table 5-8. Approximately the
same volume of non-HAP cleaners is needed as would otherwise be
needed of MeCl2. These non-HAP products are more expensive than
MeCl2 on a volume basis. The three vendors of non-HAP cleaners
contacted provided costs ranging from $310 to $1,375 per 55-
gallon drum, while 55 gallons of MeCl2 costs approximately $175
(at $0.25 per pound).40 For the representative facility costs,
an average cost of $919 per drum of the non-HAP cleaner was used.
In calculating the representative facility costs, it is assumed
that the non-HAP products are reused 3 times, meaning only around
370 gallons (6.7 drums) are needed, as compared to the equivalent
of 20 drums of MeCl2.
5-20
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TABLE 5-8. REPRESENTATIVE FACILITY COSTS FOR NON-HAP CLEANERS
Capital Investment*
Total Capital Investment $0
Annual Costs
Direct Costs*
Materials'5 $2,657
Waste treatment0 $-1,560
Indirect Costs $0
Total Annual Cost $1,097
Emission Reduction41 (tons) 4.5
Cost Effectiveness ($/ton) $244
* As discussed above, since these products are direct
replacements for MeCl2, there were no capital (equipment or
installation) costs identified. There were no additional
annual costs for labor or maintenance identified.
b Material costs were calculated as follows:
cost of MeCl2: (20 drums @ $175/drum) = $3,500/yr
cost of alternative: (6.7 drums @ $919/drum) = $6,157
$6,157 - $3,500 = $2,657
c Waste treatment costs were calculated as follows:
MeCl2 : (20 drums * .10) @ $800/drum = $l,600/yr
altern. : (6.7 drums * .10) @ $60/drum = $40/yr
This assumes that 10% of these substances will be
non-recoverable, due to contamination, and will need
to be properly disposed of.
d HAP emissions will be replaced by a small amount of VOC
emissions from the use of these products
5-21
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5.3 REFERENCES
1. A. Williams, EC/R Inc., to D. Svendsgaard, EPA:ESD:OCG.
February 10, 1995. Non-confidential summary of Flexible
Polyurethane Foam Information Collection Request (ICR) Data.
2. Telecon: P. Norwood, EC/R Inc., to D. Sullivan, Hickory
Springs Manufacturing Co. July 14, 1993.
3. Telecon: A. Williams, EC/R Inc., to D. Sullivan, Hickory
Springs Manufacturing Co. May 7, 1994.
4. Reference 3.
5. Telecon: A. Williams, EC/R Inc., to D. Sullivan, Hickory
Springs Manufacturing Co. May 6, 1994.
6. Reference 3.
7. Florentine, C., T. Griffiths, M. Taverna, and B. Collins.
Auxiliary Blowing Agent Substitution in Slabstock Foams.
Paper produced by Cannon. Received by EC/R Inc. on June 15,
1994.
8. B. Collins, Cannon USA, to A. Williams, EC/R Inc. June 15,
1994. Letter transmitting information on the CarDio™
Process.
9. Reference 7.
10. Reference 8.
11. Reference 8.
12. Telecon: A. Williams, EC/R Inc., to B. Collins, Cannon USA.
July 19, 1994.
13. L. Spellmon, Foamex, to B. Jordan, EPArESD. October 25, 1993.
Letter discussing Variable Pressure Foaming (VPF).
14. L. Spellmon, Foamex, to A. Williams, EC/R Inc. July 7, 1994.
Letter transmitting cost information on the variable pressure
foaming technology.
15. Reference 14.
16. S. Carson. Controlled Environment Foaming: Manufacturing a
New Generation of Polyurethane Foam. Prepared for FOAM ONE.
17. Reference 16.
18. Telecon: D. Ramazzotti, Edge-Sweets Co., to A. Williams, EC/R
Inc. July 1, 1994.
5-22
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19. Telecon: A. Williams, EC/R Inc., to D. Ramazzotti, Edge-
Sweets Co. July 20, 1994.
20. B. Collins, and C. Fawley. Cannon Enviro-Cure® Equipment
Applied to the Vertifoam and Maxfoam Processes. Presented to
the Polyurethanes World Congress 1993 - October 10-13, 1993.
p. 176.
21. B. Collins, and C. Fawley. Cannon Enviro-Cure® Equipment
Applied to the Vertifoam and Maxfoam Processes. Presented to
the Polyurethanes World Congress 1993 - October 10-13, 1993.
p. 179.
22. B. Collins, and C. Fawley. Cannon Enviro-Cure® Equipment
Applied to the Vertifoam and Maxfoam Processes. Presented to
the Polyurethanes World Congress 1993 - October 10-13, 1993.
p. 180.
23. B. Collins, and C. Fawley. Cannon Enviro-Cure® Equipment
Applied to the Vertifoam and Maxfoam Processes. Presented to
the Polyurethanes World Congress 1993 - October 10-13, 1993.
p. 181.
24. H. Stone, General Foam, to D. Svendsgaard, EPA:ESD:OCG.
December 20, 1994. Letter transmitting comments on EPA's
draft cost analysis.
25. B. Collins, and C. Fawley. Cannon Enviro-Cure® Equipment
Applied to the Vertifoam and Maxfoam Processes. Presented to
the Polyurethanes World Congress 1993 - October 10-13, 1993.
26. B. Collins, and C. Fawley. Cannon Enviro-Cure® Equipment
Applied to the Vertifoam and Maxfoam Processes. Presented to
the Polyurethanes World Congress 1993 - October 10-13, 1993.
p. 182.
27. Reference 24.
28. Reference 24.
29. Flexible Polyurethane Foam (Slabstock) Assessment of
Manufacturing Emission Issues and Control Technology,
Polyurethane Foam Association, May 17, 1993.
30. Meeting notes from June 9, 1994 meeting between PFA-member
chemical suppliers and the EPA, to discuss chemical
alternatives to ABAs.
31. Reference 30.
32. Reference 1.
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33. Telecon: A. Williams, EC/R Inc., to B. Janicek, Flexible Foam
Products. May 17, 1994.
34. Telecon: A. Williams, EC/R Inc., to G. Williams, Nu-Foam
Products. May 18, 1994.
35. Reference 33.
36. Reference 34.
37. Dynaloy, Inc. Material Safety Data Sheet on Dynasolve CU-5
(XUS-5). Transmitted via facsimile to A. Williams, EC/R Inc.,
from S. Riddick, Dynaloy, Inc. July 20, 1994.
38. C. McDaniel, Urethane Technologies, Inc., to A. Williams, EC/R
Inc. April 28, 1994. Information sheet on Strip-TZ®
biodegradable solvent.
39. Reference 37.
40. Reference 37.
5-24
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6. 0 SUMMARY
Tables 6-1 and 6-2 summarize the representative facility
costs for the emission reduction technologies included in this
analysis for molded and slabstock foam, respectively.
Conclusions of this analysis are discussed in this section.
The technologies investigated can be grouped into three
basic categories: (1) chemical substitutions, (2) alternative
process equipment, and (3) combinations of (1) and (2). The
implementation of these types of technologies will result in
partial or total changes in the existing polyurethane foam
production methods.
There are special challenges in attempting to estimate the
costs of these changes. In general, the capital costs of
conversion were readily obtainable. However, several elements of
the annual cost were particularly difficult to obtain or
estimate. These include the operating labor, utility costs, and
maintenance and repair costs. Therefore, the level of
uncertainty in some of the annual cost estimates is relatively
high.
Two other considerations of these process-modifying
technologies that are extremely difficult to incorporate into
costs are (l) site-specific applicability problems, and
(2) changes in product quality. A process modification may not
be technically feasible for the products and processes at one
facility, while it may work quite well at a facility producing a
relatively similar foam product.
6.1 MOLDED FOAM
The three emission source types at molded foam facilities
studied in this analysis (mixhead flushing, mold release agents,
and foam repair) account for approximately 88 percent of the
total HAP emissions reported in the ICRs.1 This analysis shows
that there are cost-effective options for completely eliminating
HAP emissions from these three sources at molded foam facilities.
However, as noted above, there may be limitations, due to product
differences, that cannot be adequately included in a simplified
6-1
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cost analysis.
The telephone conversations with vendors and foamers
revealed that small molded foam facilities that continue to use
large amounts of HAP's tend to be extremely specialized. Each
has unique technical and economic considerations that must be
considered in the application of many of the technologies
studied. Therefore, a technology may be generally considered to
be cost-effective, but it may not be truly cost effective for a
specific molded facility.
For mixhead flushing, this analysis shows three options with
cost-effectiveness values less than $1,150 per ton that totally
eliminate the use of HAPs for mixhead flushing. However, two of
the three, non-HAP flushes and self-cleaning mixheads, are not in
widespread use in this industry. This could be an indicator that
there are technical problems in their application, or that there
are prohibitive costs that are not reflected in this analysis.
Another explanation offered by vendors was that these options are
relatively new and just have not had time to penetrate the
market. Also, while this analysis shows the high-pressure
mixheads to be cost-effective, there are technical limitations
for some product lines, and many small molded foam companies are
not able to bear the initial capital investment.
There are also many technical challenges associated with the
elimination of HAPs in foam repair adhesives and mold release
agents. However, the extensive utilization of non-HAP products
for these functions leads to the conclusion that the technical
hurdles can be overcome.
6.2 SLABSTOCK FOAM
The emission source types included in this analysis for
slabstock foam (ABA usage, equipment cleaning, and fabrication)
make up over 99 percent of the total HAP emissions reported in
the ICRs.2 This analysis shows that cost-effective solutions
exist to completely eliminate HAP emissions from these sources,
which would virtually eliminate all HAP emissions at slabstock
foam facilities.
The use of equipment cleaning technologies that use no HAP's
6-4
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is common. The use of non-HAP and water-based adhesives is also
widespread, although challenges remain in the production methods
for these products. For these two emission sources, the EPA
believes that it can be concluded that HAP's could be totally
eliminated with demonstrated, cost-effective technologies.
However, the total elimination of HAP ABA presents numerous
problems that are not reflected in the representative facility
costs. Many of these problems are associated with foam product
quality. For instance, a complete range of foam grades can be
produced using forced-cooling techniques without any ABA.
However, it is generally agreed that the low-density foams
produced in this manner would not be of an acceptable quality for
the United States market.
Proponents of variable pressure foaming, controlled
environment foaming, and liquid CO2 as an ABA maintain that the
foam quality of all grades will be acceptable. However, since
none of these technologies has been in full-scale operation in
the United States for an extended period of time, it is too early
to draw conclusions regarding the technical feasibility of
operation, or the acceptability of products in the United States
market.
Acetone as an ABA is the only alternative studied in this
analysis that (1) completely eliminates HAP ABAs, and (2) has
been demonstrated in full-scale production in the United States.
However, there are limitations in the application of this
technology. One is the increased safety hazard due to the
flammability of acetone. Another is that this is not a
"pollution prevention" option, since MeCl2 emissions are being
replaced by acetone emissions. This may be of less concern if
acetone is no longer considered to be photochemically reactive.
Pentane as an ABA has also been demonstrated in the United
States, but it was not included in this analysis.
Chemical alternatives have been widely demonstrated in the
reduction of HAP emissions from the use of ABAs. The costs for
chemical alternatives probably represent the most realistic
estimate of costs in this analysis. These costs take into
6-5
-------
account technical limitations and product quality, since the
formulations used are representative of actual formulations
currently used in the industry.
The fundamental conclusion that can be drawn from this
preliminary analysis is that cost-effective solutions that
essentially eliminate HAP emissions from flexible polyurethane
foam facilities are available. Technical feasibility and product
quality issues will need to be addressed, but they do not appear
to be insurmountable at this time.
6.3 REFERENCES
1. A. Williams, EC/R Inc., to D. Svendsgaard, EPA:ESD:OCG.
February 10, 1995. Non-confidential summary of Flexible
Polyurethane Foam Information Collection Request (ICR) Data.
2. Reference 1.
6-6
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TECHNICAL REPORT DATA
(Please read Instructions on reverse before completing)
i.
4.
7.
9.
REPORT NO.
EPA-453/D-95-004
2.
TITLE AND SUBTITLE
Flexible Polyurethane Foam Emission Reduction
Technologies Cost Analysis
AUTHOR(S)
PERFORMING ORGANIZATION NAME AND ADDRESS
Emission Standards Division (Mail Drop 13)
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
12. SPONSORING AGENCY NAME AND ADD
Director
Office of Air Quality Plann
Office of Air and Radiation
U.S. Environmental Protec
Research Triangle Park, N(
15
. SUPPLEMENTARY NOTES
RESS
ing and Standards
tion Agency
: 27711
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
May 1995
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANTNO.
68-D 1-0019
13. TYPE OF REPORT AND PERIOD COVERED
Preliminary Draft
14. SPONSORING AGENCY CODE
EPA/200/04
16. ABSTRACT
Under the authority of Section 1 12 of the Clean Air Act, the EPA is currently developing a Maximum
achievable control technology (MACT) standard for the manufacture of flexible polyurethane foam.
As part of this effort, the EPA initiated a study to allow the estimation of the costs of hazardous air
pollutant (HAP) emission reduction technologies for the flexible polyurethane foam industry. This
document describes this study and its results. Only technologies that are currently being used, or those
under investigation that are generally considered to be promising were included in the study.
Information on cost and emission reduction potential, as well as process and operational information,
was compiled for each technology. Information was collected from chemical manufacturers, product
vendors, trade associations, foam producers, and other sources. Once the information was collected,
it was analyzed and applied to "representative" facilities to evaluate the capital and operational costs,
as well as the emission reduction and cost effectiveness, of each alternative.
17
a.
DESCRIPTORS
Air Pollution
Hazardous air pollutants
Emission reduction
Polyurethane foam
18. DISTRIBUTION STATEMENT
Release Unlimited
KEY WORDS AND DOCUMENT ANALYSIS
b. IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group
Hazardous air pollutants
19. SECURITY CLASS (Report) 21 . NO. OF PAGES
Unclassified 80
20. SECURITY CLASS (Page) 22. PRICE
Unclassified
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U.S. Environmental Protection Agency
Region 5, Library (PL-12J)
77 West Jackson Boulevard, 12th Floor
Chicago, IL 60604-3590
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