EPA-453/R-95-011 United States Environmental Protection Agency Office of Air Quality Planning and Standards Research Triangle Park, NC 27711 EPA-453/R-95-011 September 1996 Air &EPA Flexible Polyurethane Foam Emission Reduction Technologies Cost Analysis ENVIRONMENTAL PROTECTION \ AGENCY DALLAS, TEXAS ------- FLEXIBLE POLYURETHANE FOAM EMISSION REDUCTION TECHNOLOGIES COST ANALYSIS ct a, Emission Standards Division U.S. ENVIRONMENTAL PROTECTION AGENCY - - Office of Air and Radiation -" Office of Air Quality Planning and Standards M Research Triangle Park, North Carolina 27711 O September 1996 ------- DISCLAIMER This report has been reviewed by the Emission Standards Division of the Office of Air Quality Planning and Standards, EPA, and has been approved for publication. Mention of trade names or commercial products is not intended to constitute endorsement or recommendation for use. 11 ------- ENVIRONMENTAL PROTECTION AGENCY Flexible Polyurethane Foam Emission Reduction Technologies Cost Analysis 1. The standards regulate hazardous air pollutant emissions from the production of flexible polyurethane foam. Only flexible polyurethane production facilities that are part of major sources under Section 112(d) of the Clean Air Act (Act) will be regulated. 2. For additional information contact: Mr. David Svendsgaard Organic Chemicals Group U.S. Environmental Protection Agency (MD-13) Research Triangle Park, NC 27711 Telephone: (919) 541-2380 3. Paper copies of this document may be obtained from: U.S. Environmental Protection Agency Library (MD-36) Research Triangle Park, NC 27711 Telephone: (919) 541-2777 National Technical Information Service (NTIS) 5285 Port Royal Road Springfield, VA 22161 Telephone: (703) 487-4650 ill ------- TABLE OF CONTENTS Page LIST OF TABLES vi LIST OF FIGURES ...... ........ viii 1.0 INTRODUCTION 1-1 1.1 PURPOSE OF DOCUMENT 1-1 1.2 DOCUMENT CONTENTS ...... 1-2 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 FOR CHAPTER 2.0 2-9 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 ...... 3-8 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 ..... 4-12 4.2.3 Water-based release agents ...... 4-12 4.3 ALTERNATIVE ADHESIVES 4-17 4.3.1 Hot-Melt Adhesives 4-17 4.3.2 Water-Based Adhesives ......... 4-18 4.3.3 Hydrofuse 4-21 4.4 REFERENCES FOR CHAPTER 4.0 4-23 IV ------- TABLE OF CONTENTS (continued) 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 or hydrocarbons with 5 carbons or less as ABA 5-2 5.1.2 Liquid CO2 as an ABA 5-5 5.1.3 Foaming in a Controlled Environment . . . 5-6 5.1.3.1 Variable Pressure Foaming (VPF) . . 5-8 5.1.3.2 Controlled Environment Foaming (CEF) 5-9 5.1.4 Forced-Cooling 5-13 5.1.5 Chemical Modifications 5-15 5.2 EQUIPMENT CLEANERS 5-18 5.2.1 Steam Cleaning 5-18 5.2.2 Non-HAP Cleaners 5-21 5.3 REFERENCES FOR CHAPTER 5.0 5-24 6.0 SUMMARY 6-1 6 .1 MOLDED FOAM 6-1 6.2 SLABSTOCK FOAM 6-4 6.3 REFERENCES FOR CHAPTER 6.0 6-7 v ------- LIST OF TABLES TABLE 2-1 SUMMARY OF HAP EMISSIONS FROM FLEXIBLE POLYURETHANE FOAM PRODUCTION - 1992 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 4-13 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 4-19 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™ . . . .5-7 TABLE 5-3 REPRESENTATIVE FACILITY COSTS FOR VARIABLE PRESSURE FOAMING ..... 5-10 VI ------- LIST OF TABLES (continued) TABLE 5-4 REPRESENTATIVE FACILITY COSTS FOR CONTROLLED ENVIRONMENT FOAMING 5-12 TABLE 5-5 REPRESENTATIVE FACILITY COSTS FOR ENVIRO-CURE® 5-16 TABLE 5-6 REPRESENTATIVE FACILITY CHEMICAL COSTS FOR CHEMICAL MODIFICATIONS 5-19 TABLE 5-7 REPRESENTATIVE FACILITY COSTS FOR CHEMICAL MODIFICATIONS 5-20 TABLE 5-8 REPRESENTATIVE FACILITY COSTS FOR NON-HAP CLEANERS 5-23 TABLE 6-1 SUMMARY OF REPRESENTATIVE FACILITY COSTS FOR MOLDED FOAM EMISSION REDUCTION TECHNOLOGIES . ... 6-3 TABLE 6-2 SUMMARY OF REPRESENTATIVE FACILITY COSTS FOR SLABSTOCK FOAM EMISSION REDUCTION TECHNOLOGIES 6-4 Vll ------- LIST OF FIGURES FIGURE 2-1 Polyurethane Foam Production Reactions . . . .2-4 Vlll ------- 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 EPA looked at many possible technologies, but narrowed this report to include only technologies that are currently being used, or those under investigation that are generally considered to be promising. The EPA also realizes that there are many technologies being developed that may later prove to be applicable to this industry. In no way does the EPA intend this document to be an endorsement of any one technology. The intent of this report is to examine some proven emission reduction technologies for this industry, and some of the costs associated with the installation, and use, of these technologies. 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 1-1 ------- 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. A preliminary draft of this document was distributed industry- wide for review. Any comments received were evaluated and incorporated where appropriate. Chapter 2 provides background on the industry. Chapter 3 describes the development of "representative" molded and 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 ------- 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.-1 Flexible polyurethane foam is used in furniture, bedding, automobiles, packaging materials, and carpet underlay.2 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 100 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. Another type of on-site operation at some slabstock facilities is rebond. Rebond is a process that combines ground scrap foam pieces and toluene diisocyanate (TDI) under steam and pressure to create a bonded material. This material is predominantly used to produce carpet underlay. The largest uses of slabstock foams are in furniture, carpet underlay, automotive, 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 2-1 ------- Total slabstock foam production in 1992 was approximately 550,000 tons. At the end of 1992, there were 25 companies 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. The molded producers identified tended 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. 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 50 square inches), and can range from 10 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 2-2 ------- 3 pounds per cubic foot, depending on quality and other 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 padding, 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 (C02) . 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 2-3 ------- {R}-N=C=O + H2O -> {R}-NH2 Isocyanate H H {R}-NH0 + {R2}-N=C=0 -» {R}~N, ,N~{R2} / \c/ O Reactions of isocyanate with water O {R}-N=C=0 + {P}-OH ->• (R)-N-C Isocyanate Polyol Reaction of isocyanate with polyol X0-{P} Figure 2-1. Polyurethane Foam Production Reactions thin membranes. At full foam rise, the cell membranes are 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 expressed by the number of parts (by weight) of each component 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 2-4 ------- section, one result of the isocyanate-water reaction is the liberation of C02 gas. The blowing action of this C02 is termed "water-blowing," because the C02 blowing agent is produced from the isocyanate-water reaction. Many grades of foam can be produced using only this C02 gas as a blowing agent. Increasing the amount of water in a formulation generally produces a lower-density foam, because additional C02 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 C02 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 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 2-5 ------- 14,500 tons. The second largest volume ABA in 1992 was 1,1,1-trichloroethane (TCA), at approximately 2,000 tons. Since the role of the ABA is simply to vaporize 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, compression set, and tear strength. These properties are determined using American Society for Testing and Materials (ASTM) Standard Test Methods for Flexible Cellular Materials - Slab, Bonded, and Molded Urethane Foams (D 3574-91) . 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 slabstock 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 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 2-6 ------- 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 ------- production lines occasionally produce bad batches, which are unsuitable even for rebonding. If this material contains free, unreacted TDI, it must be treated as a hazardous waste under the Resource Conservation and Recovery Act (RCRA). 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. Q — O ------- 2.7 REFERENCES FOR CHAPTER 2.0 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. 2-9 ------- 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 foam and molded foam 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 foam facility, Polyurethane Foam Association (PFA) members provided input that affected the representative facility foam formulations. Table 3-1 shows the representative slabstock foam facility, Table 3-2 shows formulation information for the representative slabstock foam facility, and the representative molded foam 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: (1) 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. 3-1 ------- TABLE 3-1. REPRESENTATIVE SLABSTOCK FOAM 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 4 hrs/day actual pouring 225 days/yr 1 (Maxfoam™) 15 feet/min 120 kW 325 tons/yr 5 tons/yr 2 55-gal drums/yr 3,520 tons/yr 10,679 gallons 70% 16 hours/day 225 days/yr ICR average ICR averages, plant visits plant visits, ICR plant visits provided by foamer calculated using formulations in Table 3-2 EPA assumption 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 $10.9 million/yr calculated from information provided by PFA chemical alternative informational work group calculated from information provided by PFA chemical alternative informational work group calculated using the total chemical cost and the PFA assumption that 80 percent of total costs are chemical costs provided by industry representatives vendor estimate $9 .88 million/yr $2.72 million/yr $0.40/lb $800 per 55-gal drum $8.5/gal 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 ------- TABLE 3-2. FORMULATION INFORMATION FOR THE REPRESENTATIVE SLABSTOCK FOAM FACILITY3 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 (25%) produced (pph polyol) (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 MeCl2 emitted 'tons/yr) 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. 3-3 ------- TABLE 3-3. REPRESENTATIVE MOLDED FOAM 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 total (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 1,688 gal/yr 75 345 gal/yr 70% $0.40/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 of used (remainder is waste) calculated calculated 3-4 ------- 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 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 fearners. 3-5 ------- TABLE 3-4. CONTRIBUTIONS TO TOTAL CAPITAL INVESTMENT DESCRIPTION Cost Factor Purchased Equipment Costs (PEC) Equipment Sales Tax Freight Total PEC Direct Installation Costs (DC) Handling and erection Electrical Piping Total DC Indirect Installation Costs (IDC) Start-up Contingencies Total IDC Total Capital Investment = PEC + DC + IDC 0.03*A 0.05*A B 0.14*B 0.04*B 0.02*B 0.20*B 0.02*B 0.03*B 0.05*B Equipment costs provided by vendor and/or foamer. 3-6 ------- 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 provided9 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 was provided by vendor and/or fearner. 3-7 ------- 3.3 REFERENCES FOR CHAPTER 3.0 1. B. Jordan, EPA:ESD, 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. 3-1 ------- 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 foam 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 also 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 responses, 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 4-1 ------- below and include non-HAP flushes, high-pressure mixheads, self-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 ------- 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 foam 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 $244, while costs of the non-HAP flushes range from $382 to $1,375 a drum.14'15-15 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 mixes the foam components by impingement of the high pressure streams within its mixhead at pressures up 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 4-3 ------- TABLE 4-1. REPRESENTATIVE FACILITY COSTS FOR NON-HAP MIXHEAD FLUSHES Capital Investment9 Total Capital Investment $0 Annual Costs Direct Costs3 Materials13 $4,770 Waste treatment0 $-7,700 Indirect Costs $0 Total Annual Cost $-2930 Emission Reductiond (tons/yr) 37.10 Cost Effectiveness ($/ton) $-79 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 @ $244/drum) = $32,940/yr cost of alternative = (45 drums @ $838/drum) = $37,710/yr $37,710 - $32,940 = $4,770 c Waste treatment costs were calculated as follows: MeCl2 treated: 13 drums @ $800/drum = $10,400/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 ------- $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 ------- 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 foam 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 foam 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 ICR responses 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 foam 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 4-6 ------- TABLE 4-2. REPRESENTATIVE FACILITY COSTS FOR HIGH PRESSURE MIXHEADS Capital Investment Purchased equipment costsa $315,900 Direct installation costsb $63,180 Indirect installation costsc $15,795 Total Capital Investment $394,875 Annual Costs Direct Costsd $0 Maintenancee $30,000 Materialsf $-32,940 Waste treatment9 $-10,400 Indirect Costs Capital Recovery11 $56,230 Administrative Charges1 $15,795 Total Annual Cost $28,685 Emission Reduction (tons/yr) 37.1 Cost Effectiveness ($/ton) $773 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 c $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 £ This technology eliminates any need for MeCl2, so there is a material cost savings of $32,940 9 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 = $15,795 4-7 ------- TABLE 4-3. REPRESENTATIVE FACILITY COSTS FOR SELF-CLEANING MIXHEADS Capital Investment Purchased equipment costs3 Direct installation costsb indirect installation costs0 Total Capital Investment Annual Costs Direct Costsd Materials6 Waste treatment* Indirect Costs Capital Recovery9 Administrative charges'1 Total Annual Cost Emission Reduction (tons/yr) Cost Effectiveness ($/ton) $108,450 $21, 690 $5,423 $135,563 $-32,940 $-10,400 $19,304 $5,423 $-18,613 37.1 $-502 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 a 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 $32,940 £ This technology eliminates any need for MeCl2, so there is a waste treatment savings of $10,400 g $135,563 * 0.1424 (7% for 10 yrs) = $19,304 h $135,563 * 0.04 = $5,423 4-8 ------- were 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 foam 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 $200.44 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 4-9 ------- TABLE 4-4. REPRESENTATIVE FACILITY COSTS FOR SOLVENT RECOVERY SYSTEMS Capital Investment Purchased equipment costs3 $35,640 Direct installation costsb $7,128 indirect installation costs0 $1,782 Total Capital Investment $44,550 Annual Costs Direct Costs Materials'3 $-24,705 Utilities6 Maintenance materials6 Replacement parts6 insufficient information ,, . . T i_ e to estimate Maintenance labor6 Operating laborf $9,600 Supervisory labor3 $1,440 Waste treatment11 $-6,000 Indirect Costs Capital Recovery1 $6,344 Overheadj 6,624 Administrative chargesk $1,782 Total Annual Cost $-4,915 Emission Reduction (tons/yr)1 27.8 Cost Effectiveness ($/ton) $-177 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 a Savings of 75 percent of MeCl2 costs due to recovery: $32,940 * 0.75 = $24,705 e 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. £ 2 hours/day * 240 days/yr * $20/hr = $9,600 g $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 4-10 ------- hold the solvent flush waste and to transport these bags to the 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 ICR responses, 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. 4-11 ------- The representative facility costs are presented in Table 4-5. The price per gallon of this reduced-VOC agent is over twice 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 was reported by two sources as ranging from $11.90 to $17.50 per gallon, so an average cost of $14 .70/gallon was used.55'56 Foam manufacturers have found that a smaller amount of mold release agent is needed when naphtha-based agents are substituted for HAP-based agents.57 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. One commenter stated that by using a low pressure, high volume gun in conjunction with a fluid regulator, they have been able to reduce consumption by 30 percent.58 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.59'60 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.61'62 However, one vendor commented that customers with multiple facilities can use the same product, and scale-up 4-12 ------- TABLE 4-5. REPRESENTATIVE FACILITY COSTS FOR REDUCED-VOC MOLD RELEASE AGENTS Capital Investment3 Total Capital Investment $0 Annual Costs Direct Costs3 Materials'3 $2,077 Indirect Costs $0 Total Annual Cost $2,077 Emission Reductionc (tons/yr) 4.6 Cost Effectiveness ($/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) 4-13 ------- TABLE 4-6. REPRESENTATIVE FACILITY COSTS FOR NAPTHA-BASED MOLD RELEASE AGENTS Capital Investment3 Total Capital Investment $0 Annual Costs Direct Costs3 Materials13 $15,443 Indirect Costs $0 Total Annual Cost $15,443 Emission Reduction0 (tons/yr) 4.6 Cost Effectiveness ($/ton) $3,359 a 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. b Material costs were calculated as follows: HAP-based: $4.82/gal * 1688 gal = $8,136/yr Naptha-based: $14.70/gal * 1604 gal = $23,579/yr $23,579 - $8,136 = cost $15,443/yr c HAP emissions will be replaced by an approximately equal level of VOC emissions. 4-14 ------- following implementation at one facility is greatly reduced as the product is implemented at the other facilities. This reduces the average facility scale-up costs for an individual customer.63 The developmental procedures can be costly in time, as well as in scrap foam, during the transitional period.64 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 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.65 Mold temperature changes may also be necessary when switching to some water-based agents, due to the higher evaporation temperature of water. One vendor was identified that stated that their technology does not require an increase in mold temperature, or increased drying time, which is another change discussed below.66 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.67'68 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.69 The cost of the water-based agents is higher per gallon than HAP-based agents, at $6.00 per gallon.70 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. 4-15 ------- TABLE 4-7. REPRESENTATIVE FACILITY COSTS FOR WATER-BASED MOLD RELEASE AGENTS Capital Investment3 Total Capital Investment $0 Annual Costs Direct Costsa Materials13 $1,992 Indirect Costs $0 Total Annual Cost $1,992 Emission Reduction (tons/yr) 4.6 Cost Effectiveness ($/ton) $433 a 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/yr Water-based: $6.0/gal * 1688 gal = $10,128/yr $10,128 - $8,136 = cost $l,992/yr 4-16 ------- 4.3 ALTERNATIVE ADHESIVES HAP-based adhesives are used in both slabstock and molded foam facilities. In slabstock foam 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.71 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 foam 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 the repair of voids and tears in the molded foam pieces. There were 26 tons of HAP emissions (less than 10 percent) reported at molded foam facilities from this source in the ICR responses.72 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.73 An additional problem is that hot melt adhesives tend to produce hard seams, which are not acceptable in a soft, flexible foam product. 4-17 ------- 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.74 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.75 There is a small electricity cost for the glue tanks.76 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. 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 $7.00 per gallon.77 The costs of this alternative for the representative slabstock and molded foam facilities are presented in Table 4-9. The increased utilities cost was not determined, but it is expected to be minimal. The usage was found to be the same for water-based adhesives as for HAP-based. It was assumed that no additional heat source was used at the representative facility, 4-18 ------- TABLE 4-8. REPRESENTATIVE FACILITY COSTS FOR HOT-MELT ADHESIVES Capital Investment Purchased equipment costsa Direct installation costs indirect installation costsb Total Capital Investment Annual Costs Direct Costs0 Materials'3 Utilities6 Indirect Costs Capital Recoveryf Administrative charges9 Recovery Credits Total Annual Cost Emission Reduction11 (tons/yr) Cost Effectiveness ($/ton) a $3,000 * 6 = $18,000 18,000 + [18,000 * (0.03 tax + 0.05 freight)] = Slabstock $19,440 0 $970 $20,410 $93,491 $149 $2,906 $816 $0 $97,362 43 $2,264 $19,400 Molded $6,480 0 $340 $6,820 $3,015 $50 $971 $273 $0 $4,309 1.34 $3,216 (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) c 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) e 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 £ $20,410 * 0.1424 (7% for 10 yrs) = $2,906 (slabstock) $6,820 * 0.1424 (7% for 10 yrs) = $971 (molded) g $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 4-19 ------- TABLE 4-9. REPRESENTATIVE FACILITY COSTS FOR WATER-BASED ADHESIVES Capital Investment Slabstock Molded Total Capital Investment3 $0 $0 Annual Costs3 Direct Costs Materials13 $-15,699 $-508 Utilities0 Indirect Costsd 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 ------- 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.78 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- 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.79 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.80 The usage for hydrofuse is less than for HAP-based adhesives, but the percentage difference was not quantified. 4-21 ------- TABLE 4-10. REPRESENTATIVE FACILITY COSTS FOR HYDROFUSE ADHESIVE Capital Investment Slabstock Molded Purchased equipment costs3 $16,200 $5,400 Direct installation costs $0 $0 indirect installation costsb $810 $270 Total Capital Investment $17,010 $5,670 Annual Costs Direct Costs0 Materials* $5,446 $176 Utilities6 Indirect Costs Capital Recovery£ $2,422 $807 Administrative charges9 $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) 9 $17,010 * 0.04 = $680 (slabstock) $5,670 * 0.04 = $227 (molded) 4-22 ------- 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 Polyurethane 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 ------- 18 19 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32, 33, 34 35 36 37 A. Williams, EC/R Inc., to D. Svendsgaard, EPA:ESD:OCG. May 27, 1994. Memorandum discussing information gathered from manufacturers of HP mixheads. 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. to M. Pritchard, Admiral to F. Solomon, Hennecke to M. Mangold, Foamex, LP. Telecon: A. Williams, EC/R Inc Corp. May 25, 1994. Telecon: A. Williams, EC/R Inc Machinery. May 25, 1994. Telecon: A. Williams, EC/R Inc April 12, 1994. Reference 20. Reference 21. Telecon: A. Williams, EC/R Inc., to R. Hogue, Krauss Maffei Corp. May 25, 1994. R. Hogue, Krauss-Maffei Corp., to A. Williams, EC/R Inc. June 1, 1994. Letter transmitting cost information . Reference 21. Reference 26. Reference 21. M. Mangold, Foamex, LP, to D. Svendsgaard, EPA:ESD:OCG. January 10, 1995. Telecon: A. Williams, EC/R Inc., to G. Lewis, Klockner Ferromatik Desma. May 18, 1994. Reference 31. Reference 22. Reference 19. Reference 31. Reference 31. Telecon: A. Williams, EC/R Inc., to G. Lewis, Klockner Ferromatik Desma. July 15, 1994. 4-24 ------- 38. 39. 40. 41. 42. 43 44, 45, 46 47, 48, 49, 50. 51, 52, 53, 54 55 56 Telecon: A. Williams, EC/R Inc., to D. Peck, Renosol Corp. June 7, 1994. Telecon: A. Williams, EC/R Inc., to S. Smoller, E-A-R Specialty Corporation. June 10, 1994. Reference 38. Reference 39. Telecon: A. Williams, EC/R Inc., to D. Majewski, Renosol Corp. June 10, 1994. Reference 42. Reference 42. 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. Reference 42. 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. Reference 1. Telecon: A. Williams, EC/R Inc. Products. April 21, 1994. Telecon: A. Williams, EC/R Inc. Products. July 11, 1994. Reference 49. Reference 50. Reference 50. Telecon: A. Williams, EC/R Inc, Corp. July 14, 1994. Reference 54. to J. Robinson, Air to J. Robinson, Air to M. Gromnicki, Swenson H. Mauersberger, Foam Design, to S. Wyatt, EPA:OAQPS:ESD. June 1, 1995. Letter transmitting comments on the May 1995 preliminary draft of the "Flexible Polyurethane Foam Emission Reduction Technologies Cost Analysis." 4-25 ------- 57. Telecon: A. Williams, EC/R Inc., to D. Majewski, Renosol Corp. July 19, 1994. 58. Reference 56. 59. Reference 49. 60. Telecon: A. Williams, EC/R Inc., to C. Asuncion, Air Products. April 20, 1994. 61. Reference 49. 62. Reference 60. 63. R. Santo, Air Products, to S. Wyatt, EPA:OAQPS:ESD. June 8, 1995. Letter providing additional comments on the May 1995 preliminary draft of the "Flexible Polyurethane Foam Emission Reduction Technologies Cost Analysis." 64. Reference 60. 65. 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. 66. Reference 63. 67. Reference 49. 68. Reference 60. 69. Reference 60. 70. 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. 71. Reference 1. 72. Reference 1. 73. H.B. Fuller Company, Technical Data Sheet on Hot Melt Adhesive (Product No. HL-6278). 74. Telecon: A. Williams, EC/R Inc., to D. Kehr, H.B. Fuller Company. June 22, 1994. 75. Reference 74. 76. Telecon: A. Williams, EC/R Inc., to D. Brauen, Nordson Corp. June 27, 1994. 4-26 ------- 77. Telecon: A. Williams, EC/R Inc., to M. Lechowicz, Midwest Industrial Chemical Co. June 22, 1994. 78. H.B. Fuller Company Technical Data Sheet for Hydrofuse (Product No. WC-0686-A 770). June 22, 1994. 79. Reference 74. 80. Telecon: P. Norwood, EC/R Inc., to A. Abraham, H.B. Fuller Co. July 28, 1994. 4-27 ------- 5.0 EMISSION REDUCTION TECHNOLOGIES AND COSTS: SLABSTOCK FOAM Information was obtained for emission reduction technologies for three HAP emission sources at slabstock foam 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 vaporize 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 responses, at over 14,600 tons, accounting for over 79 percent of the total HAP emissions from slabstock foam facilities.I 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, hydrocarbons with 5 carbons or less, such as pentane, or liquid CO2 as an ABA, foaming in a controlled environment, forced cooling, and chemical modifications. These alternatives are discussed in the following sections. The optimal solution for some facilities may be a combination of one or more of the above alternatives, however, the cost discussions will only address using individual alternatives. 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. It is the opinion of several foam manufacturers that certain technologies discussed in 5-1 ------- this chapter may diminish the quality of some foam grades. However, the best way to determine comparability of foam quality properties is through in-use testing, and no quantification data has ever been submitted by any industry members to reinforce this view. Therefore, due to a lack of test data comparing the foam properties of the same grades of foam made by different methods, the EPA's analysis assumes that foam properties are comparable, unless detailed information was provided that stated otherwise. 5.1.1 Acetone or hydrocarbons with 5 carbons or less as ABA In response to environmental concerns over the use of MeCl2, 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 foam manufacturers are $0.30/lb for acetone versus $0.40/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). 5-2 ------- 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 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, and has recently been delisted as a VOC (60 FR 31633). The costs of applying this system to the representative slabstock foam plant are presented in Table 5-1. All capital, labor, and licensing costs were provided by Hickory Springs.6 Hydrocarbons with 5 carbons or less, such as pentane or butane, are currently in use as an ABA alternative by at least one facility. These chemicals have similar properties as acetone, including increased flamability over MeCl2. However, it is important to note that these chemicals may be volatile organic compounds (VOC), which would reduce the environmental benefits of switching to them over other options. A detailed analysis of this technology was not done due to incomplete information. Retrofit installation costs were provided by one manufacturer as follows: Purchased equipment costs $250,000 Direct installation costs $300,000 Indirect installation costs $125,OOP Total capital investment $675,000 5-3 ------- TABLE 5-1. REPRESENTATIVE FACILITY COSTS FOR ACETONE AS AN ABA Capital Investment Purchased equipment costs3 $161,700 Direct installation costs3 $32,300 indirect installation costs3 Total Capital Investment $194,000 Annual Costs Direct Costs Materials13 $-152,600 Utilities0 $5,881 Maintenance materials6 $2,500 Licensing6 $46,460 Maintenance laborf $2,500 Indirect Costs Capital Recovery51 $27,626 Overhead11 $1,500 Administrative charges1 $7,760 Total Annual Cost $-58,373 Emission Reduction (tons/yr) 325 Cost Effectiveness ($/ton) $-180 a 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 (358,000 Ibs). 358,000 Ibs * $0.3/lb = $107,400 for acetone/yr 325 tons/yr MeCl2 = 650,000 Ibs 650,000 Ibs * $0.40/lb = $260,000 for MeCl2/yr. $107,400 - $650,000 = $-152,600 (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 D. Sullivan, Hickory Springs Manufacturing Co. e Licensing fee for 358,000 Ib/yr: 50,000 Ib * $0.16 = $8,000 75,000 Ib * $0.14 = $10,500 233,000 Ib * $0.12 = $27,960 total licensing fee = $46,460 £ Quoted by D. Sullivan, Hickory Springs Manufacturing Co. 9 $194,000 * 0.1424 (7% for 10 yrs) = $27,626 h $2,500 * 0.6 = $1,500 i $194,000 * 0.04 = $7,760 5-4 ------- 5.1.2 Liquid C02 as an ABA A procedure for using liquid C02 as the ABA in slabstock foam manufacture called CarDio™ has been developed by the Cannon Group, and is patented worldwide, available under license by Foaming Technologies Cardio B.V. There is currently one full scale CarDio™ unit in operation in the United States, and another four plants are planned to be installed and in operation by the end of the third quarter of 1995.7 The largest benefit of CarDio™ is that it completely eliminates HAP emissions.8 Another benefit is the chemical cost savings, as C02 is less expensive than MeCl2, and it only requires 33 percent as much C02 as MeCl2 to produce the same amount of ABA-blown foam.9 The CarDio™ system operates by adding liquid C02 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.10 The retrofit kit consists of:11 - CO2 metering pump assembly with mass flowmeter - Polyol/activator booster pump assembly - C02/polyol premixing unit - CarDio™ mixing head - Necessary pipework and valves - Flushing system - Laydown device - Controls 5-5 ------- The costs of applying this system to the representative slabstock foam plant, as provided by the vendor, are presented in Table 5-2. The cost of the retrofit kit for the representative facility is approximately $375,000, excluding installation. However, the EPA did receive a comment from one company using this system that stated they have found the capital costs to be higher.12 The liquid C02 costs approximately $85 to $120 per ton depending on usage, and the necessary tank can be rented for $500 per month.13 Not all foam formaulations can be made with the CarDio™ process, as there is a minimum C02 requirement to attain a stable froth. This amount will vary depending on the size of the machine, but for this analysis a cut-off point of 3 ppm MeCl2 was used to determine which foam grades at the representative facility could not be made using CarDio™14 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 C02 cool. There is a licensing fee, which is 1 percent of the chemical cost for Cardio™ made foam, which the industry representative stated was $0.72/lb.15 There were no increased labor or maintenance costs identified.16 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. 5-6 ------- TABLE 5-2. REPRESENTATIVE FACILITY COSTS FOR CARDIO™ Capital Investment Purchased equipment costs3 $405,000 Direct installation costsb $24,300 indirect installation costs0 $0 Total Capital Investment $429,300 Annual Costs Direct Costs Materials'* $-235,832 Utilities6 $3,600 Carbon dioxide tank rentalf $6,000 Licensing9 $66,528 Indirect Costs Capital Recovery11 $61,132 Administrative charges1 $17,172 Total Annual Cost $-81,400 Emission Reduction (tons/yr)j 309 Cost Effectiveness ($/ton) $-263 a $375,000 +[375,000 * (0.03 tax + 0.05 freight)] = $405,000 b $405,000 * 0.06 = $24,300 c Included in Cannon's licensing agreement d 325 tons MeCl2 * .33 = 107 tons CO2 107 tons C02 * $102.5/ton = $10,968 308.5 tons MeCl2/yr = 617,000 Ibs 617,000 Ibs * $0.40/lb = $246,800 for MeCl2/yr $10,968 - $246,800 = -$235,832 e Additional electricity costs: 100 kw * 900 hr = 90,000 kw-h 90,000 kw-h * $0.04/kw-h = $3,600/yr £ tank rental $500/month 9 (7,000 Ibs foam * .66) * 2000 = 9,240,000 Ibs foam $0.72/lb * 9,240,000 Ibs = $6,652,800 * 0.01 = $66,528 h $429,300 * 0.1424 (7% for 10 yrs) = $61,132 1 $429,300 * 0.04 = $17,172 3 HAP emission reduction replaced by around 108 tons/yr of CO2. Only 95 percent reduction as not all foam will be made using C02. 5-7 ------- 5.1.3.1 Variable Pressure Foaming (VPF) The VPF system technology is owned by Prefoam, and Foamex International is an equity holder in the company and has contributed a patent (U.S. 4,777,186) to Prefoam. The patent covers the use of foaming in a chamber with overpressure. The process is available for license from Prefoam. The system involves processing foam in an enclosed chamber under a controlled pressure. The pressure in the chamber is fixed before 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. 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 ICR responses) from the foaming process .17'18 The conversion of an existing facility to VPF will involve the installation of a new foaming chamber, revisions to the 5-8 ------- existing line, and an extended shutdown period. Cost information for VPF was obtained directly from Foamex.19'20 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. The higher end of the range would be for long block (200 ft) production. The cost can be reduced by shortening block length or lowering of overpressure or vacuum required.21 However, this is offset somewhat by a savings in chemical costs due to the elimination of the need for MeCl2 and for labor savings due to the increased automation.22 The costs of applying this system to the representative slabstock foam plant are presented in Table 5-3. Other potential cost savings for this system were identified but not included in the analysis due to insufficient information. For some facilities there would be a cost savings from the elimination of state and federal taxes imposed on ABA's. There may also be reduction or elimination of premium polyols such as high resilience and polymer grafted polyols. This may result a cost savings of $.20 per pound of polyol used. There is also a reduction in the top skin thickness when VPF is used, resulting in improved prime foam yield. The savings will vary with facility production.23 5.1.3.2 Controlled Environment Foaming (CEF) FOAM ONE company has developed and patented a polyurethane foam manufacturing process, which is called Controlled Environment Foaming (CEF). The CEF process is a discrete block production method which uses a containment vessel to control the pressure and temperature during foaming. The system consists of two molds (as large as 10 feet long by 9 feet wide by around 4 feet tall). One mold is inside a pressure-controlled containment vessel, and the other is outside this vessel. During production, foam is poured into the mold inside the containment vessel, which is lined with a flexible polyethylene film liner. The foam reaction is allowed to take place under the controlled conditions of the containment vessel. 5-9 ------- TABLE 5-3. REPRESENTATIVE FACILITY COSTS FOR VARIABLE PRESSURE FOAMING Total Capital Investment*1 Annual Costs Direct Costs Materials13 Utilities0 labord Indirect Costs Capital Recovery6 Overhead^ Administrative charges3 Total Annual Cost Emission Reduction (tons/yr) Cost Effectiveness ($/ton) $4,500,000 $-260, 000 $15, 600 $-23,100 $640,800 $-13,860 $180,000 $539,440 325 $1,660 a Provided by Foamex. Assumed to include all direct and indirect installation costs. b 325 tons MeCl2 * 2000 Ibs/ton * $0.40/lb = $260,000 c Provided by Foamex. d Provided by Foamex e $4,500,000 * 0.1424 (7% for 10 yrs) = $640,800 £ $-23,100 * 0.6 = $-13,860 9 $4,500,000 * 0.04 = $180,000 5-10 ------- 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.24 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.25 While there are low energy requirements and low maintenance expenses, the production rate is considerably slower than a traditional Maxfoam line.26 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 foam 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 foam facility are presented in Table 5-4. The estimated cost of the CEF equipment provided by the vendor was $250,000. In the annual cost calculations, it was assumed that 2 additional operators were needed, and that the energy requirements were approximately equal to a Maxfoam line.27 It is assumed that any additional maintenance costs for the CEF system would be offset by the reduced maintenance on the Maxfoam line due to the reduction in its use. 5-11 ------- TABLE 5-4. REPRESENTATIVE FACILITY COSTS FOR CONTROLLED ENVIRONMENT FOAMING Capital Investment Purchased equipment costs3 Direct installation costsb indirect installation costs0 Total Capital Investment Annual Costs Direct Costs'1 Materials6 Operating laborf Supervisory labor9 Utilities11 Indirect Costs Capital Recovery1 Administrative chargesj Total Annual Cost Emission Reduction (tons/yr) Cost Effectiveness ($/ton) $270, 000 $54, 000 $13,500 $337,500 $-260, 000 $144,000 $21,600 $12,960 $48,060 $13,500 $-19,880 325 $-61 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 a 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 £ 2 operators * 16 hrs/day * 225 days/yr * $20/hr = $144,000/yr 9 $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 1 $337,500 * 0.1424 (7 percent for 10 years) = $48,060 3 $337,500 * 0.04 = $13,500 5-12 ------- 5.1.4 Forced-Cooling The two primary functions of an ABA are to reduce the density of the foam and to provide cooling effects. Increasing the amount of water in the formulation will reduce the foam density, but increases the exothermicity of the reaction, which can lead to bun scorching or even auto-ignition after the bun exits the foam tunnel. The cooling of the bun by mechanical means can eliminate this potentially dangerous situation, while allowing the production of low density foams. Information was obtained and reviewed on two different patented types of forced-cooling techniques that are in full-scale operation: Enviro-Cure® by Grain Industries and Rapid-Cure® by General Foam. The EPA is also aware of other companies experimenting with similar forced cooling processes. Since the Enviro-Cure® technology is fully operational at several facilities across the United States, the following discussion focuses on this system. Many of the Enviro-Cure® systems in operation in the United States are installed on Vertifoam® lines. Vertifoam® is a vertical, rather than horizontal foam line.28 Grain is the only company currently using Vertifoam® in the United States. Grain has also retrofit a traditional Maxfoam system, designed and installed by Cannon USA, with Enviro-Cure® to produce foam blocks up to 60 feet long. This type of retrofit is described in the following section, but the general Enviro-Cure® principle is applicable to the Vertifoam® system as well. The Maxfoam Enviro-Cure® system is an enclosure with an associated conveyor system, which is put in place after the traditional slabstock foam pouring line. The cut blocks from the Maxfoam machine are transferred to the unit, where a special multi-slat conveyor system transports the block through the cooling enclosure.29 There is a slight delay before th$ 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.30 5-13 ------- 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.31 There are some differences in the forced cooling systems. The Enviro-Cure® system for Vertifoam® is limited to producing short blocks because of the Vertifoam® block length limitations. However, Enviro-Cure® can be used on a Maxfoam system for producing blocks of any given length as set prior to construction. Rapid-Cure® can be used both in-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 and the plant layout. 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 used, which in turn depends on production rates and amounts.32 No other detailed costs were provided. Enviro-Cure® provides no exhaust purification. The cost information used for the representative facility was obtained from a paper written by Cannon-Viking, the manufacturers of the Enviro-Cure® machine.33 The cost of the Enviro-Cure® system will depend upon the layout of the facility, and can range from $500,000 to 2.2 million dollars. The cost depends mainly upon facility layout and the length of the buns to be produced. For a complete Maxfoam conversion, the cost can range from 1 to 2.2 million dollars.34'35 A cost of $2 million was used for the representative facility, assuming that the retrofit would need to be extensive. 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 5-14 ------- 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 MeCl2.36 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.37 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. 5.1.5 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.38 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 formation of secondary crosslinkers such as allophanates and biurets. 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.39 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 5-15 ------- TABLE 5-5. REPRESENTATIVE FACILITY COSTS FOR ENVIRO-CURE® Capital Investment Purchased equipment costs3 $2,000,000 Total Capital Investment $2,000,000 Annual Costs Direct Costsb $0 Utilities0 $18,400 Materials6 $0 Licensing Fee6 $148,219 Indirect Costs Capital Recoveryf $284,800 Administrative chargesg $80,000 Total Annual Cost $531,419 Emission Reduction (tons/yr) 325 Cost Effectiveness ($/ton) $1, 635 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 Material cost savings of $260,000 is offset by increased polyol costs (see text) e 0.015 * $9,881,263 = $ 148,219 f $2,000,000 * 0.1424 (7% at 10 yrs) = $284,800 9 $2,000,000 * 0.04 = $80,000 5-16 ------- 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, 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 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.40 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 5-17 ------- 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 foam machine parts such as mixheads and foam troughs. This use resulted in six tons of emissions (less than 1 percent of total slabstock foam HAP emissions).41 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 (producing rebond foam), while the other had to purchase a generator specifically for steam production.42'43 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 5-18 ------- CO S o M B M CD H Q i W ft O CO CO o u a u ffi U a H I S W CO W H I in W CQ 4J CQ O U ~ M rH >, id ^ u > 0) U CQ O -H ~ CQ JH CQ >i -H \ g TO H C O 0) T) , U 0- rH (0 6 T) ^ (U e •o E 4J CQ 4J id g CQ 0) U id g T) rl G O id M-I CO T) g CQ a) 4J J3 H u id m g T3 rl C o id t-i 4-) CQ TJ ^ W (1) >i 3 3 CQ O Tf C ' 600 id ^i 4-) 4J — -H in CQ U G tt CO — Q cu •o VomOOOOOOOHfflVO'i'^OOOfflCNnCNHOOt^li) CD vo H H •W- H •w- 00 en 00 •W- 00 H in CN m in oooooooooooooooooooooo ooinooooooooooooooooooM o o in OHHH HHH HHHHHHOJ ooinoooooooooooooooooo OHHHHHHHHHHHHHHHHHHHH W 5-19 ------- TABLE 5-7. REPRESENTATIVE FACILITY COSTS FOR CHEMICAL MODIFICATIONS Capital Investment Purchased equipment costs3 $25,380 Direct Installation Costsb $5,076 Indirect Installation Costsc $1,269 Total Capital Investment $31,725 Annual Costsd Direct Costs Materials6 $270,397 Indirect Costs Capital Recovery^ $4,518 Administrative charges3 $1,269 Total Annual Cost $276,167 Emission Reduction11 (tons/yr) 147 Cost Effectiveness ($/ton) $1, 879 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 $11,168,420 - $10,898,023 = $270,397 (See Table 5-6) f $31,725 * 0.1424 (7% for 10 years) = $4,518 g $31,725 * 0.04 = $1,269 h 325 tons - 178 tons = 147 tons (see Table 5-6) 5-20 ------- hoses.44 The facility using a gas-fired mobile steam generator estimated their costs to be between $3,000 and $5,000.45 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 not HAP-based. The solvents they contain are furanone, cyclic amide, ethyl ester, other esters, N-Methylepyrrolidone (NMP), and D-limonene.46-47 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.48 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 foam 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 5-21 ------- 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).49 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. 5-22 ------- TABLE 5-8. REPRESENTATIVE FACILITY COSTS FOR NON-HAP CLEANERS Capital Investment3 Total Capital Investment $0 Annual Costs Direct Costs3 Materials13 $2,009 Waste treatment0 $-1,320 Indirect Costs $0 Total Annual Cost $689 Emission Reduction3 (tons) 4.5 Cost Effectiveness ($/ton) $153 a 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: (17 drums @ $244/drum) = $4,148/yr cost of alternative: (6.7 drums @ $919/drum) = $6,157/yr $6,157 - $4,148 = $2,009/yr c Waste treatment costs were calculated as follows: MeCl2 : (17 drums * .10) @ $800/drum = $l,360/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 5-23 ------- 5.3 REFERENCES FOR CHAPTER 5.0 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. 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. B. Collins, Cannon U.S.A., to A. Williams, EC/R Inc. June 9, 1995. Facsimile Transmitting Comments on the May 1995 preliminary draft of the "Flexible Polyurethane Foam Emission Reduction Technologies Cost Analysis." 8. 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. 9. B. Collins, Cannon USA, to A. Williams, EC/R Inc. June 15, 1994. Letter transmitting information on the CarDio™ Process. 10. Reference 8. 11. Reference 9. 12. S. Watson, Carpenter Co., to S. Wyatt, EPA:OAQPS:BSD. July 10, 1995. Letter transmitting comments on the May 1995 preliminary draft of the "Flexible Polyurethane Foam Emission Reduction Technologies Cost Analysis." 13. Reference 9. 14. Reference 7. 15. Reference 7. 16. Telecon: A. Williams, EC/R Inc., to B. Collins, Cannon USA. July 19, 1994. 17. L. Spellmon, Foamex, to B. Jordan, EPA:ESD. October 25, 1993. Letter discussing Variable Pressure Foaming (VPF). 5-24 ------- 18. R. Hay, Foamex International Inc., to A. Williams, EC/R Inc. June 1, 1995. Letter transmitting comments on the May 1995 preliminary draft of the "Flexible Polyurethane Foam Emission Reduction Technologies Cost Analysis." 19. L. Spellmon, Foamex, to A. Williams, EC/R Inc. July 7, 1994. Letter transmitting cost information on the variable pressure foaming technology. 20. Reference 18. 21. Reference 18. 22. Reference 18. 23. Reference 18. 24. S. Carson. Controlled Environment Foaming: Manufacturing a New Generation of Polyurethane Foam. Prepared for FOAM ONE. 25. Reference 24. 26. Telecon: D. Ramazzotti, Edge-Sweets Co., to A. Williams, EC/R Inc. July 1, 1994. 27. Telecon: A. Williams, EC/R Inc., to D. Ramazzotti, Edge- Sweets Co. July 20, 1994. 28. 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. 29. 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. 30. 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. 31. 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. 32. H. Stone, General Foam, to D. Svendsgaard, EPA:ESD:OCG. December 20, 1994. Letter transmitting comments on EPA's draft cost analysis. 5-25 ------- 33. 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. 34. 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. 35. M. Crawford, Grain Industries, to A. Williams, EC/R Inc. June 9, 1995. Letter transmitting comments on the May 1995 preliminary draft of the "Flexible Polyurethane Foam Emission Reduction Technologies Cost Analyis." 36. Reference 33. 37. Reference 33. 38. Flexible Polyurethane Foam (Slabstock) Assessment of Manufacturing Emission Issues and Control Technology, Polyurethane Foam Association, May 17, 1993. 39. Meeting notes from June 9, 1994 meeting between PFA-member chemical suppliers and the EPA, to discuss chemical alternatives to ABAs. 40. Reference 39. 41. Reference 1. 42. Telecon: A. Williams, EC/R Inc., to B. Janicek, Flexible Foam Products. May 17, 1994. 43. Telecon: A. Williams, EC/R Inc., to G. Williams, Nu-Foam Products. May 18, 1994. 44. Reference 43. 45. Reference 43. 46. 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. 47. C. McDaniel, Urethane Technologies, Inc., to A. Williams, EC/R Inc. April 28, 1994. Information sheet on Strip-TZ® biodegradable solvent. 48. Reference 47. 49. Reference 47. 5-26 ------- 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 (1) 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 ICR responses.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 6-1 ------- •H CQ ^ ,, -U CQ C •ft U Q) O n I) C 4-) ft 14-1 i ^^ U 4H (U <0- H > — CQ P'ra t> CQ •H 6 ° -H - CQ ^ >, •H ^ M £ In *-• rtii 1 ^^^ rj to 4-> ^ ^ 3 CQ >, fi c o > rt3 ' — ' rH C 1 _J d) rH to e fO 4-> P, *-~ 4->-H ^> H ITS JJ H O rH O 4-J <— ' i~* G Ui rCj fO U rH /i\ /^ .on Reduction Te representative i emissions) ri f~t CQ *-* CQ W ,-> J>, ^v, CQ a o H CQ rH T3 (I) -rl 2 CQ tn ti -H £> to CQ X o\° O O H H £ CQ tn G -H > to CQ O on-HAP flushes a ro F~ r- a (100%) H ro in 00 to ^ 00 CN in r- 00 - «* CM ro CQ T3 to (U 3 igh-pressure mi W CQ Cn -H > to CQ a o o H H r- ro CO tn £ •rl > 10 CQ ro yj in - in ro H CQ T) tO 0) A X elf-cleaning mi CO CQ tn ti •H J> tO CQ 53 0\<> in r- oo CN CQ tn pj •H J> (0 CQ O in in <. vjl *f olvent recovery CO elease Agent ons/yr) Ptf 4-> T3 ro rH • 0 H CN in ^f X o o H U> -* ^ r~ o *. CN O CQ educed-VOC agen P4 CM in ro >. ro X 0\° O O H kO * ro "vj* ^ •. in H 0 CQ 4J ti V tn to T) QJ CO ,Q a tO a ro ro <3< a o o H U> •* CN cr> CTl ^ H O CQ 4-) ater-based agen S . . >i CQ ti O 4J VO 10 OJ g tO O VD H CN .. ro tH o\o O O H ro H en 0 ro i* ^ 0 CN 00 .. U) 4J rH E i 4-1 O a CQ tn -rl £> (0 CQ a o o H ro H CQ tn rj •rl ^ tO CQ O ater-based £c ro o cr> a 0\<> 0 O H ro H o H CN «. H O [^ vo ^ in ydrofuse a o- U c o o CQ C O -H CQ 03 -H E 0) •H 4J CQ 0) CD O iH O C! ^! U (U 4J o -H 4J U o •H CO CQ -H s 0) 0) X! 4J CQ 0) O Q 6-3 ------- 1 cu _ 4-1 -H CO S CQ 4J CO H o u m -rl e w c** •H "I"} rH CQ T> >i _CQ g\ 10 g ^ 4J . rH ^ 7J rd 4J rH 5 3 DB^, rl d U > r5j • — 4-) r~i /ji i .w \L/ rH TO c rd 4J R -— 4J -H •£ */> 0 a$~- EH OS g U d H 4-1 _, d o rt W J -•-4 r^ r; a 3sion Reduct Technology •esentative emissions) •rl « p a la ^ rH — * 4J d cu 01 y Blowing A tons/yr) M in (0 O3 -H ro rH ' — ' •H 1 CO aving CQ X — o o H in O3 ro CO Oi a -rH > m CQ o 0 o V ^J) cr> rH 0) a o 4-1 cu u CQ aving CQ a CTl CTl O ro CO Oi a •H > rt CO o o ro •. CTl 03 •* (N 0 u •H tj1 -H i_I| O vo VD H * ~ O O H in 03 n o ^ ^f h. CT> ro in o o o .. o o m ^ cu rH iable Press ming rH (0 ro O > Cu CO aving CO a 0\° O O H in 03 ro CQ 01 c -H > rd CQ o 0 in >. r- ro ro 4-) d cu E d o rH •H trolled Env ming d rd o o O Cu in ro H a 0\° O O H in O3 ro m H ^ «. H ro in 0 0 o -. 0 o o 03 ck-Cooling -rl ^3 a oo H 53 in in P-J ^ VD H ^ v^ ^•s. 03 in O3 r> -. H ro CQ d O •H 4J rd 0 -H mical Modif (U C* U ^-, rH ^1 ^^ CQ d o 4-) d o -H 4J rd U -H rH A VD 03 CM X O 0 H ro CM vo ro «. c- CTl 0 H Sji •. 0 O3 CQ CU ^ •H -melt adhes 4J o W CQ aving CQ 8 o 0 H ro CQ Oi d •H [> rd CQ 0 CO cu -rH CQ CU T) fO 0) CQ rd rH CU 4-1 rd [2 CTl CTl H 8 0\° O O H ro 00 <3< in ^ 00 o H O .. r> H rofuse rrj J>^ ffi . — , rH ^^ CQ d o 4-) in Oi d •H d rd CU rH U i ro in H * o 0 H in CTl oo U) o CQ )H -HAP cleane d o o- U a o O CO fi O -H CQ CQ -H E cu d -H CQ CU SH O rH O a X! o cu a o •H -U U CU O -H CQ CQ -H CU CU CO 0) O Q 6-4 ------- limitations, due to product differences, that cannot be adequately included in a simplified 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 foam facility. For mixhead flushing, this analysis shows three options with cost-effectiveness values less than $800 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 ICR responses.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. 6-4 ------- The use of equipment cleaning technologies that use no HAP's 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 C02 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 6-5 ------- estimate of costs in this analysis. These costs take into 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. 6-6 ------- 6.3 REFERENCES FOR CHAPTER 6.0 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. Reference 1. 6-7 ------- TECHNICAL REPORT DATA (Please read Instructions on reverse before completing) 1. REPORT NO. EPA-453/R-95-011 2. 4. TITLE AND SUBTITLE Flexible Polyurethane Foam Emission Reductic Cost Analysis m Technologies 7. AUTHOR(S) 9. 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 ADDRESS Director Office of Air Quality Planning and Standards Office of Air and Radiation U.S. Environmental Protection Agency Research Triangle Park, NC 27711 3. RECIPIENT'S ACCESSION NO. 5. REPORT DATE September 1996 6. PERFORMING ORGANIZATION CODE 8. PERFORMING ORGANIZATION REPORT NO. 10. PROGRAM ELEMENT NO. 11. CONTRACT/GRANT NO. 68-D6-0008 13. TYPE OF REPORT AND PERIOD COVERED 14. SPONSORING AGENCY CODE EPA/200/04 15. SUPPLEMENTARY NOTES 16. ABSTRACT This document describes the costs of hazardous air pollutant emission reduction technologies for flexible polyurethane foam production facilities. The information in this document provides the background for the estimate of impacts for the proposed National Emission Standards for Hazardous Air Pollutant Emissions from Flexible Polyurethane Foam Production (40 CFR 63, Subpart III). 17. KEY WORDS AND DOCUMENT ANALYSIS a. DESCRIPTORS Ah- Pollution Hazardous air pollutants Emission reduction Flexible Polyurethane Foam 18. DISTRIBUTION STATEMENT Release Unlimited b. IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group Hazardous air pollutants 19. SECURITY CLASS (Report) 21. NO. OF PAGES Unclassified 86 20. SECURITY CLASS (Page) 22. PRICE Unclassified EPA Form 2220-1 (ReT. 4-77) PREVIOUS EDITION IS OBSOLETE ------- |