United States Environmental Protection Agency Air and Energy Engineering Research Laboratory Research Triangle Park, NC 27711 Research and Development EPA/600/SR-93/044 May 1993 &EPA Project Summary Characterization of Emissions from the Simulated Open-Burning of Non-Metallic Automobile Shredder Residue Jeffrey V. Ryan and Christopher C. Lutes The reclamation process for recy- clable ferrous and non-ferrous metals from scrap automobiles generates a non-metallic waste product called "fluff," consisting of a combination of plastics, rubber, glass, wood products, and electrical wiring. The waste prod- uct is often stockpiled or landfilled. A number of these stockpiles have caught fire, resulting in the emission of nu- merous air pollutants. To gain insight into the types and quantities of these air pollutants, a study was conducted in which the open combustion of fluff was simulated and the resulting emis- sions collected and characterized. Samples were collected and analyzed for volatile and semivolatile organics, particulate, and metal aerosols. Typical combustion process gases—carbon di- oxide, carbon monoxide, nitric oxide, oxygen, and unburned hydrocarbons— were monitored continuously. The samples were analyzed using gas chro- matography (GC)/mass spectroscopy, GC/flame ionization detection, gravimet- ric, and atomic emission methodolo- gies to identify and quantify the types of compounds present in the open com- bustion process emissions. The result- ing mass/volume concentrations were related to the measured net mass of material consumed through combus- tion and known dilution air volume to derive an estimate of overall emissions. Volatile and semivolatile organics char- acterized included mono- and polyaro- matic hydrocarbons, substituted alkanes and alkenes, aldehydes, nitrites, phenols, chlorinated aromatics, hetero- cycles, and polychlorinated dibenzodi- oxins and furans. Of the 11 metal aero- sols characterized, cadmium, copper, lead, and zinc were found in significant quantities. The emission characteriza- tions performed indicated that substan- tial quantities of air pollutants are emitted. For the organic pollutants alone, the emission of more than 200 g/kg of fluff combusted was observed. This Project Summary was devel- oped by EPA's Air and Energy Engi- neering Research Laboratory, Research Triangle Park, NC, to announce key find- ings of the research project that is fully documented in a separate report of the same title (see Project Report ordering information at back). Introduction The reclamation process for ferrous and non-ferrous metals from scrap automo- biles generates a non-metallic waste prod- uct called "fluff." For the most part, fluff consists of a combination of plastics such as polyethylene, polypropylene, acryloni- trile-butadiene-styrene, polyurethane foam, polyvinylchloride, rubber, glass, wood prod- ucts, cloth, paper, dirt, and electrical wir- ing. Conservatively, it can be estimated that 9.1 x 108 kg (2 x 109 Ib) of fluff is produced annually. The automobile fluff is discarded at land- fills or, more commonly, stockpiled on site. At several automobile reclamation facili- ties, these stockpiles have caught fire. One such stockpile fire, in Montvale, VA, burned for 38 days emitting unknown quan- tities of potentially harmful air pollutants. It was estimated that 13,000-16,000 bales Printed on Recycled Paper ------- of fluff, weighing approximately 1,360 kg (3,000 Ib) each, were burned in the fire. During the fire, several attempts were made both to extinguish it and to acceler- ate combustion. The Commonwealth of Virginia's Department of Air Pollution Con- trol contacted EPA's Control Technology Center (CTC) requesting emissions data on combustion of this material. Unfortu- nately, data pertaining to the open burn- ing of fluff or any similar material were extremely limited. As a result, the CTC felt that a study characterizing the emissions resulting from the open combustion of fluff was warranted. Under contract to EPA's Air and Energy Engineering Research Laboratory (AEERL), Acurex Environmen- tal performed a study which identified and quantified organic and inorganic emission products produced during the simulated open combustion of fluff. The study was designed to roughly estimate emission rates (within an order of magnitude) for volatile arid semivolatile organics, particu- late, and selected metal aerosols identi- fied in combustion emissions. Emphasis was placed on gaining a broad overview of the pollutants produced. Experimental The project consisted of replicate tests to collect and qualitatively and quantita- tively characterize organic and inorganic emissions resulting from the simulated open combustion of actual automobile fluff waste. Small quantities (9-11 kg, 20-25 Ib) of fluff, obtained from an automobile rec- lamation facility, were combusted in a test facility designed for simulation of open combustion conditions (see Figure 1). A representative air sample from the burn hut environment is delivered to a sam- pling facility, adjacent to the burn hut. The sampling facility contains most of the associated sampling equipment: the volatile organic sampling train (VOST) sys- tem, the semivolatile organics/particulate sample collection systems, and the par- ticulate removal system for the continuous emission monitors (CEMs). Fixed combustion gases—carbon mon- oxide (CO), carbon dioxide (CO2), nitric oxide (NO), oxygen (02), and unburned hydrocarbons (THC)—were measured con- tinuously using on-line process analyzers. Volatile organics were collected using the VOST system. Semivolatile organics and particulate were collected using a sample system modified for use in this study. Two separate semivolatile organic/particulate collection systems were operated simulta- neously during the test period. One sample system was used to collect samples for general semivolatile organic and particu- Sample Duct Fluff Combustion Container Air Inlet Air Inlet Weighing Platform Figure 1. Diagram of burn hut. late characterization, while the remaining system was used to collect samples for polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) analyses. A separate particulate sampling system was used to collect metal aero- sols. A medium volume (4 cfm, 0.00189 m3s) ambient particulate sampler was used to collect particulate 10-um in diameter and less. The VOST samples were analyzed by gas chromatography/mass spectroscopy/ flame ionization detection (GC/MS/FID) on a purge-and-trap thermal desorption sys- tem. Compounds were identified using multi-component calibration standard com- parisons, mass spectral library searches, and investigator interpretation. Identified analytes were quantified using a combi- nation of GC/MS and GC/FID system re- sponses based on the characteristics of the identified compound. The semivolatile organics from the gen- eral organics samples were retrieved from the collection media by soxhlet extraction using dichloromethane. The XAD-2 was extracted separately from the particulate fraction. Both the particulate extracts and the XAD-2 extracts were analyzed indi- vidually for total chromatographable or- ganics (TCO)—(organic compounds with boiling points of 100-300 °C)—and total gravimetric organics (GRAV)—(organic compounds with boiling points > 300 °C). Individual semivolatile organic com- pounds were identified and quantified us- ing an approach similar to that used for the volatile organics. The XAD-2 and par- ticulate extracts were analyzed separately by GC/MS to obtain mass spectral infor- mation. The mass spectra of acquired data were compared to mass spectra of multi- component standard mixes as well as the mass spectral database to assign com- pound identification. Identified analytes were quantified using a combination of GC/MS and GC/FID system responses based on the characteristics of the com- pound identified. The PCDD/PCDF samples were ana- lyzed by low resolution GC/MS. Isotopi- cally labeled homologues for all congeners were used for qualitative and quantitative purposes. Metals potentially present in fluff were chosen for characterization. The samples were analyzed by inductively coupled ar- gon plasma-atomic emission (ICAP) for aluminum (Al), arsenic (As), barium (Ba), ------- cadmium (Cd), total chromium (Cr), cop- per (Cu), lead (Pb), magnesium (Mg), se- lenium (Se), and zinc (Zn). Results and Discussion Nominally, 11 kg (25 Ib) of fluff was evaluated for each test. Not all of the material tested was actually combusted during the testing. Only about 45% of the mass of fluff placed in the combustion apparatus was actually combusted during the 200 min test. The remaining ash and incombustible material was not character- ized. Maximum burn rates were observed within 20 min of material ignition. After this time, burn rates gradually decreased throughout the burn. Peak temperatures, observed by a thermocouple placed di- rectly over the combustion apparatus, cor- relate well with peak burn rates. Similarly, peak concentrations for CO, CO2, and NO emissions, correlate reasonably well with peak burn rates. During the burns, O2 concentrations remained greater than 19%. GC/MS analysis of the collected VOST samples identified more than 50 com- pounds. However, for the range of volatile compounds characterized, more than 100 peaks were evident in the GC/FID chro- matograms. Most of the compounds iden- tified were alkanes, alkenes, cycloalkanes, and alkyl substituted aromatics. However, aldehydes, ketones, alcohols, nitriles, and chlorinated aromatics were also identified. The types of volatile compounds identified are consistent with compounds identified during thermal decomposition studies of individual plastics. Figure 2 depicts estimated emissions for volatile organic compounds (VOCs) common to Title III of the Clean Air Act Amendments' (CAAA) Hazardous Air Pol- lutants (HAP) list. Benzene represents the largest single VOC emitted, generating nearly 10 g for every kg of fluff consumed in combustion. The compounds identified in the XAD-2 and particulate fractions are similar to the types of compounds identified in the VOST samples. In addition, phenols, polycyclic aromatic hydrocarbons (PAHs), phthalates, and heterocycles were identified. Again, the types of compounds identified were consistent with the types of organics iden- tified in various studies of the thermal decomposition of plastics. Many of the compounds identified common to the HAP list were PAHs. Table 1 presents estimated emissions data for selected individual compounds present in the XAD-2 and particulate frac- tions. Because of the complexity of the sample and its components, identifying all Uj 40 35 30 25 20 S 15 .^ "w Uj 10 Benzene Toluene Chlorobenzene T77\ Ethyl Benzene I 1 M/PXylene 1 ' I ' I Test 1, Sample 1 ' Test 2, Sample 1 ' Test 3, Sample 2 ' Test 1, Sample 3 Test 2, Sample 2 Test 3, Sample 3 Figure 2. Estimated emissions for volatile HAPs. compounds present in the organic frac- tions was not within the scope of this study. Separate samples were also collected for characterization of PCDD/PCDF emis- sions. Separate analyses were performed on the XAD-2 and particulate filter samples. The total PCDD/PCDF emission results are summarized in Figure 3, Overall, the resulting emissions favored the formation of the less-substituted chlo- rinated dibenzofurans. The tetrachloro and pentachloro dibenzofurans (TCDF/PeCDF) were roughly an order of magnitude greater in concentration than the dioxin homo- logues. These profiles are similar to those observed from soil samples collected from scrap automobile incineration sites in the Netherlands. Of the 11 metals targeted, only Cd, Cu, Pb, and Zn were detected in the samples collected. Figure 4 presents the emission rates for these metals. It is interesting that Cu is present in relatively large concentra- tions; Cu compounds have been investi- gated as catalysts in the formation of PCDDs/PCDFs in municipal waste incin- eration processes. Particulate matter was collected by sev- eral different sampling systems: the semi- volatile organics systems, the metal aerosol system, and the PM10 (airborne particles with diameters < 10 urn) ambient sampler. A comparison of the PM10 to total particulate, based on total averaged values, indicates that PMin consists of about 40% of the total particulate matter collected. To assess the overall organic emissions, the volatile and semivolatile organics emis- sion data were summarized. The total or- ganics emitted (volatile, vapor-phase semivolatile, and particulate-bound semi- volatile) averaged more than 200 g/kg fluff combusted. The actual mass contribution from each fraction is summarized in Table 2. As a measure of the quality of esti- mated mass emissions, a total mass bal- ance was performed. The diversity of the measurements performed during testing enabled the determination of total mass emissions: they included most classes of observed products of incomplete combus- tion as well as several common gaseous products of complete combustion. The ac- tual mass balances, based on individual and overall test average emission rate values, are presented in Table 3. Summary and Conclusions The primary objective of this study was to characterize, as completely as possible, the emissions resulting from the simulated open combustion of fluff. This necessi- tated an approach where qualitative infor- mation was given greater emphasis than quantitative information. This approach pro- vided the data and insight to direct subse- quent, specialized, and more quantitatively detailed investigations. An attempt was made to characterize the diversity of the emissions as efficiently as possible. ------- Table 1. Estimated Emissions for Selected Pollutants (g/kg) Compound Ethyl Benzene m- or p-Xylene Ethynyl Benzene Styrene Benzaldehyde Phenol 1,2 Dichlorobenzene Naphthalene Methylethylphenol Biphenol Acenaphthylene Caprolactam Phenanthrene Fluoranthrene Pyrene Terphenyl Bis(-2Ethylhexyl)- phthalate XAD Test 1 2.26 1.03 0.38 6.27 1.20 1.39 ND 0.90 0.49 0.29 0.20 ND 0.211 ND ND ND ND XAD Test 2 2.05 1.11 0.39 6.49 1.53 1.59 0.17 0.95 ND 0.30 0.18 ND 0.177 ND ND ND ND XAD Average 2.16 1.07 0.38 6.38 1.36 1.49 0.09 0.92 0.24 0.29 0.19 0.000 0.194 0.000 0.000 0.000 0.000 Particulate Particulate Test 1 Test 2 ND ND ND ND ND ND ND ND ND ND ND ND 0.068 ND 0.110 0.050 0.761 ND ND ND ND ND ND ND ND ND ND ND 0.380 0.129 0.109 0.118 0.070 1.995 Particulate Average 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.190 0.099 0.055 0.114 0.060 1.378 ND = Not Detected The diversity of data produced from this study is sufficiently comprehensive to pro- vide a semiquantitative characterization of the emissions resulting from the simulated open combustion of automobile recycling fluff. While the data may be adequate from a physical and chemical character- ization standpoint, data are lacking as to the toxic effects from these emissions. The relationship of this experiment to ac- tual uncontrolled fluff combustion has not been established. 0.0032 0.003 0.0028 0.0026 oi 0.0024 S 0.0022 0.002 0.0018 0.0016 0.0014 0.0012 0.001 0.0008 0.0006 0.0004 0.0002 0 TCDDs PeCDDs ^H First Fluff Test ES8SSI Second Fluff Test Third Fluff Test I I Average HxCDDs TCDFs PeCDFs HpCdds OCDDs HxCDFs HpCDFs OCDFs Figure 3. Total estimated PCDD/PCDF emissions. ------- Only Detected Metals Shown g o w .w 1 1 CO .w LU First Fluff Test Second Fluff Test Third Fluff Test I I Average Cadmium Copper Figure 4. Estimated emissions for selected metals. Zinc Table 2. Estimated Emissions for Classes of Pollutants (g/kg) Day 1 Day 2 Table 3. Mass Balance for Combustion Emissions (g/kg) Day 1 Day 2 Day 3 Day 3 Average Volatiles: Early in test 5.93 43.06 25.73 24.91 Mid-test 17.28 69.16 70.87 52.44 Late in test 62.54 NA 58.44 60.49 Semivolatiles: XAD-2 TCO 56.99 50.05 90.72 65.92 XAD-2GRAV 6.68 10.12 23.58 13.46 Paniculate TCO 0.61 1.27 0.85 0.91 Particulate GRAV 53.78 69.11 113.71 78.87 Particulates: General Organic Train 91.25 116.17 183.44 130.29 Dioxin Train 85.82 115.68 188.63 130.04 Metals Train 81.55 89.93 174.49 115.32 Average (3 trains) 86.20 107.26 182.19 125.22 PM 66.03 NA 41.11 53.57 Average Volatiles 28.58 56.11 51.68 45.46 Vapor-phase Semivolatiles 63.67 60.17 114.30 79.38 Particulate 86.20 107.26 182.19 125.22 (Average 3 trains) COasC 67.93 71.54 72.09 70.52 CO asC 915.71 746.30 771.93 811.31 NO2asN NA 2.54 2.43 2.49 Sum 1162.10 1043.92 1194.62 1134.37 NA = Not Available •U.S. Government Printing Office: 1993 — 750-071/60246 ------- ------- ------- J.V. Ryan and C.C. Lutes are with Acurex Environmental Corporation, Research ' Triangle Park, NC 27709. Paul M. Lemieux is the EPA Project Officer (see below). The complete report, entitled "Characterization of Emissions from the Simulated Open-Burning of Non-Metallic Automobile Shredder Residue," (Order No. PB93- 172914; Cost: $19.50), will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Air and Energy Engineering Research Laboratory U.S. Environmental Protection Agency Research Triangle Park, NC27711 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati, OH 45268 Official Business Penalty for Private Use $300 BULK RATE POSTAGE & FEES PAID EPA PERMIT No. G-35 EPA/600/SR-93/044 ------- |