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Energy conservation through recycling of used oil
Ecological Engineering 36 (2010) 1761–1764
Contents lists available at ScienceDirect
Ecological Engineering journal homepage: www.elsevier.com/locate/ecoleng
Energy conservation through recycling of used oil Zenon Pawlak a,b,∗ , Wieslaw Urbaniak b , Tadeusz Kaldonski c , Michal Styp-Rekowski d a
Tribochemistry Consulting, Salt Lake City, UT 84117, USA Biotribology Laboratory, University of Economy, Garbary 2, 85-229 Bydgoszcz, Poland c Military University of Technology, Mechanical Engineering, Department of Tribology, Warsaw, Poland d University of Natural Sciences, Department of Mechanical Engineering, 85-789 Bydgoszcz, Poland b
a r t i c l e
i n f o
Article history: Received 14 February 2010 Received in revised form 8 August 2010 Accepted 23 August 2010
Keywords: Oil collection Recycling Ecological conservation Hazardous metals
a b s t r a c t This study concentrates on the investigation of energy and environmental benefits for used oil pertaining to its reuse through: (i) recovering the heating value of used oils in a combustion process and (ii) re-refining of used oil to produce fresh lube oil products. Tests were made with the used oil samples by ICP technique and the results were compared with standard requirements. We have found that the problems could successfully be solved through used oil management practices including collection centers, transporters, and processors by providing encouragement and financial support towards the re-refining industry. The novelty and value of our work lies in the conclusion that reformulation of motor oil results in lower levels of hazardous elements in used oils. © 2010 Elsevier B.V. All rights reserved.
1. Introduction The collection and recycling of used motor oil from our cars, trucks, motorcycles, boats, RVs, or lawnmowers is the best way to protect the environment from this hazard and conserve energy resources (Mitsch and Jorgensen, 2003, 2004). A used lubricant is not ecologically safe, but by its technical and physical properties corresponds to the requirements of beneficial reuse. Recycling keeps oil out of our groundwater supplies, thus protecting drinking water resources. Used motor oil can be reprocessed into fuel that can be used in furnaces for heat, or in power plants to generate electricity for homes, schools and businesses. Used motor oil can also be re-refined into lubricating oils that meet the same API specifications as virgin motor oil (American Petroleum Institute, www.recycleoil.org; Pawlak, 2003). The recycling (reprocessing, re-refining) allows recovery of mineral base oil, which is a valuable part in the production of lubricating oil used as a clean fuel and to create many petroleum-based products. One gallon (3.8 kg) of used oil can be re-refined into 2.3 kg of lubricating oil. For comparison, a 42-gallon (150 kg) barrel of crude oil typically contains only 1/2 gallon (1.9 kg) of lubricant-quality base oil (Lin and Mendelssohn, 1998). The composition of new lubricating oil consists primarily of a base oil which is a heavy end distillate of crude oil with the
boiling range of 325–600 ◦ C. It contains approximately 44% of straight chain and branched chain alkanes (primary C18 through C34 , 29% of cycloalkanes, 22% of aromatics, 4.2% of total aromatics and 3.2% of total naphthalene. Major additive classes (10–20 vol%) include corrosion and rust inhibitors, antioxidants, emulsifiers, detergents and dispersants, viscosity and color stabilizers, and anti-wear additives. The additives usually contain calcium, zinc, magnesium, molybdenum, phosphorus, sulfur and bromine compounds (Pawlak, 2003). The US federal government does not consider used oil that is destined for recycling a hazardous waste. There are three states, however, that have classified used oil as a hazardous waste (California, Massachusetts, and Rhode Island). These three states require a special handling of used oil. In all other states, used oil is handled like a typical household hazardous waste such as paints, varnishes, pesticides, and many cleaning products. Used oil in the USA is defined in Title 40 of the Code of Federal Regulations (CFR) part 279 as “any oil that has been refined from crude oil, or any synthetic oil, that has been used and as a result of such use is contaminated by physical or chemical impurities” (ATSDR, 1997). The following are examples of used oil: used lubricants, synthetic oils, transmission and brake fluids, refrigeration oils, compressor oils, hydraulic fluids, and heat transfer fluids. 1.1. Used oil specification
∗ Corresponding author at: Tribochemistry Consulting, Salt Lake City, UT 84117, USA. Tel.: +1 801 277 3936. E-mail addresses: [email protected], g.c.dotro@cranfield.ac.uk (Z. Pawlak). 0925-8574/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.ecoleng.2010.08.007
Used oil that has a flash point less than 38 ◦ C, dilution of contaminated used oil that contains PCBs or organic halogen compounds in excess of the maximum allowable concentrations
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Z. Pawlak et al. / Ecological Engineering 36 (2010) 1761–1764
Table 1 Used oil property and constituent limits. Property/constituent
Maximum allowable level, ppm
Arsenic Cadmium Chromium Lead Sulfur Polychlorinated biphenyls (PCBs)a Total organic halogens as chlorineb Flash point
5.0 2.0 10.0 100.0 Variable, mostly 1.0% Variable, mostly 2.0 1000 or 4000 38 ◦ C
a “Polychlorinated biphenyls” or “PCBs” means chlorobiphenyls that have the molecular formula C12 H10−n Cln in which “n ” is greater than 2. b “Organic halogen compound” means an organic chemical compound in which one or more halogen elements are incorporated.
prescribed in Table 1 is regulated (ATSDR, 1997; Magiera et al., 2003). The burning and marketing of used oil is subject to state and federal environmental regulations. Each state has adapted the federal EPA used oil management rules in Title 40 of the Code of Federal Regulations (CFR), part 279 and additional state used oil management requirements (Padma et al., 2004). The combustion conditions in most cement kilns can provide the safe incineration conditions for PCBs at a temperature exceeding 1200 ◦ C and the residence time of 4 s. Under federal regulations, used oil or fuel produced from used oil exceeding the limits set by US EPA can be burned for energy recovery only in industrial and utility boilers, industrial furnaces, hazard waste incinerators, and used oil-fired space heaters that meet specified provisions [CFR, section 279.11]. California regulates used oil as a hazardous waste. California generates more than 150 million gallons (495 million kg) of used oil annually and recycles just 59%. In California, US EPA allows the burning of used oil that is generated by the owner or operator of the unit or received from do-it-yourselfers in used oil-fired space heaters (ATSDR, 1997; Boughton and Horvath, 2004). This paper will discuss the most recent quality management of used oil collectors, re-recyclers and current trends, with suggestion on how to remove the major impediment in the way of achieving higher levels of lube oil re-refining in the US, EU and Australia. The used oil samples were tested and results compared with standards requirements.
2. Materials and methods 2.1. Analysis of used oil content in the United States of America Oil samples were collected from petroleum refinery and petrol stations in the years 2000 and 2009. Samples were digested with nitric acid and hydrogen peroxide using the hot block digestion procedure and EPA method was used to quantify metals (U.S. SW846, 1986; Rauckyte et al., 2006; Keith, 1994). Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used for analysis of total metals. A calibration standard was prepared from a multi-element standard. Three standards and one blank were used for calibration. The standard samples were prepared in a nitric acid/hydrochloric acid matrix, as specified in method 6010 (U.S. SW-846, 1986). The performance of the instrument was evaluated by determining the detection limit (DL) for each metal and several quality control (QC) parameters. The results of method reported level (MRL) values are (ppm): arsenic 0.5, cadmium 0.5, chromium 0.06, lead 0.30. During the analysis, several QC checks were performed to ensure that the ICP spectrometer was operating properly (see Table 2).
Table 2 Analytical data for used oil samples: halogen, pH, total metal concentrations and flash point values collected in the years 2000a and 2009b . Halogens, ppm
pH
520a 370a 480a 470a 390a 370b 343b 370b
8.6 7.3 8.5 7.9 8.1 8.2 8.4 7.8
Zn, ppm 1040 1110 1140 980 1230 820 677 690
Cd, ppm
Cr, ppm
2.8 3.0 3.3 4.2 5.9 2.1 2.8 2.7
3.9 4.2 5.8 3.4 6.9 2.7 2.9 3.1
Pb, ppm 102 70 140 105 93 53 33 47
Flash point, ◦ C 46 53 59 52 49 43 49 47
Quality control parameters: Standard reference material, SRM (95–104% recovery), continuing standard, CSTD (94–104%), lab spike blank, LSB (96–103%), lab spike blank duplicate, LSBD (95–104%), lab spike matrix, LSM (94–107%), lab spike matrix duplicate, LSMD (95–106%) were used as references for categorizations. Accuracy (% recovery) was determined as a ratio of LSB(found) and LSB(true) (96–104%), and precision (relative % difference (LSB − LSBD)/1/2(LSB + LSBD)); (3–8%).
3. Results and discussion 3.1. A review of used oil management practices in three regions of the world 3.1.1. Used oil program in the US The used oil program in the US has been decentralized and is under each state’s management and supervision. In Utah, for example, the state Department of Environmental Quality (DEQ) implemented effectively a program of collection and disposal of do-it-yourselfer (DIYer) used oils. Utah DIYer used oil collection represents only 4.5% (520,614 gallons) (1.7 million kg) of the total used oil collection in the US. The total quantity of used oil collected in Utah by registered used oil transporters in 2005 was 11,515,729 gallons (49 million kg) (State of Utah, 1997, 2005). Oil samples were analyzed for total metal content and halogens (see Table 2). Eight oil samples have surpassed regulatory limit for cadmium, which is 2.0 ppm. The good situation is in the case with chromium with a limit of 10 ppm. Three oil samples surpassed regulatory limit for lead which is 100 ppm. The lead concentrations determined in samples collected in 2009 (Table 2) are much lower than those reported in earlier studies (in the 1980s and 1990s) (Table 3) due to the change of unleaded gasoline standard in 1996. Lead has been blended with gasoline since the early 1920s. The EPA began working to reduce lead emission in 1973, gradually to one tenth of a gram per gallon by 1986. The average lead content in gasoline in 1973 was 2–3 g per gallon, or about 200,000 tonnes of lead per year (ATSDR, 1997). The used oil should not exhibit any hazardous characteristics (ignitability, corrosivity, toxicity and reactivity) that render waste hazardous. In addition, used oil must not contain polychlorinated biphenyls (PCBs) at a concentration at or above 5 parts per Table 3 Concentration of potential hazardous heavy metals, total halogens in used oils burned as a fuel in the 1980s and 1990s in the United States (Vermont Agency, 1996). Analyte
Mean concentration (ppm) in the 1980s
Concentration range (ppm) in the 1990s
Virgin fuel oil (ppm)
Arsenic Barium Cadmium Chromium Lead Zinc Halogens
20 137 4.0 38 555 707 5500
Not analyzed 1–7 0.3–7 2–7 20–146 570–2370 100–440
0.06 13 1.0 4.1 4.1 2.0 5.7–7.8
Z. Pawlak et al. / Ecological Engineering 36 (2010) 1761–1764 Table 4 Production of lubricating oil, its collection and loss to the environment in the US, EU and Australia. Country
Production
Used oil collection
Loss to the environment
USA
4.5 billion kg
Australia
465 million kg
EU
5 billion kg
780 million gallon, or 2.6 billion kg 180 million kg 2.5 billion kg
200 million gallons, or 660 million kg 54–88 million kg 100 million kg
million (ppm), or halogens (e.g., compounds containing chlorine, bromine, and fluorine) above 1000 ppm. Used oil containing more than 1000 ppm halogens is presumed to be mixed with halogenated hazardous wastes and must be managed as such, unless the generator of the waste can demonstrate otherwise (Vermont Agency of Natural Resources, 1996), (see Table 3). Table 3 shows the distinct decrease in barium, chromium, lead and halogens content for used engine oils for the last two decades. 3.1.2. Oils collections in the European Union The EU15 Waste Oil Directive 75/439/EEC, as last amended by Directive 2000/76/EC, is designed to create a harmonized management for used oils. The Directive also aims to protect the environment against the harmful effects of illegal dumping and of treatment operations. The EU consumed in 2003 roughly 5 billion tonnes of lubricating oils a year (see Table 4). Some half of that quantity purchased would become waste oils (the rest is lost either during use or through leakages, etc.) That leaves us with approximately 2.5 million tonnes of waste oil to manage every year in the EU. The average collection rate in the EU15 is around 81% (Magiera et al., 2003; Kajdas, 2000; Environment, www.ec.europe; Hein, 2005; Prado-Jatar and Brown, 1997). 3.1.3. Used oil recycling across Australia Australian lubricants are manufactured from crude oil imported from the Middle East, because domestic crude oils are not suitable for making base stock. Australia’s annual consumption of virgin lubricant is around 465 million kg, while about 180 million kg of used oil is recovered. Around 27–36 million kg of used oils are stockpiled across Australia (Used Oil Recycling, 2009; CPSS, 1999; Stachowiak, 2007). More than 400 oil collection points have been set up in Australia and further 300 are under construction. Around 75% of collected
Fig. 1. Comparison of used oil collection and lost to environment.
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used oils are reused as a burner fuel in cement and lime kilns, furnaces and industrial burners. At present, only one company, Environmental Oil in Victoria state, converts around 20% of used oil into a product that meets the current specification for diesel. Less than 3% of the recovered used oils are re-refined to base lubricating oils (CPSS, 1999). The Product Stewardship for Oil Program (PSOP) was introduced in 2001 by Australian Government to provide incentives to increase used oil recycling. The Government has spent AU$34.7 million over 7 years to support the implementation the PSOP. The additional benefit ceased after 30 June 2009 (DeMarco, 2005; CPSS, 1999; Product Stewardship, 2000, www.austlli.au; Robinson et al., www.aspo-australia.org.au). 4. Conclusions The US, EU and Australia provide financial incentives to motivate the re-refinery industry to gain the number of operators to increase production capacity. The study identified an option to integrate various industry representatives including used oil collectors and transporters, used oil processors, including used oil refiners, representatives of the used oil consuming group, and automotive dealers associations. The study of energy and environmental requirements for used oil concerns deals with the heating value in the combustion process, and re-refining of used oil. The oil can therefore be reused in producing fresh lube oil products. Currently in the USA, 780 million gallons (2.6 billion kg) of used oil are estimated to be recycled each year. Approximately 83% of this amount is burned and 17% is re-refined, while in the European Union these figures are 77% and 33%, and in Australia 97% and 3%, respectively. A comparison of used oil collection and of oil lost to the environment in the US, EU and Australia is shown graphically in Fig. 1. Compared to the USA, it appears that most European countries are more advanced in the area of used oil recycling and reuse, with two to three times as great processing capacity. Acknowledgement This work was partially funded by the University of Economy in Bydgoszcz. References American Petroleum Institute (API), 2010. Used Motor Oil—Collection and Recycling, www.recycleoil.org. ATSDR, 1997. Agency for Toxic Substances and Disease Registry. Toxicological Profile for used Mineral-based Crankcase Oil. U.S. Department of Health and Human Services, Atlanta, GA. Boughton, B., Horvath, A., 2004. Environmental assessment of used oil management methods. Environ. Sci. Technol. 8, 353–358. CPSS, 1999. Comprehensive Product Stewardship System (CPSS) for Waste Oil—Discussion Paper, Environment Australia, www.oilrecycling.gov.au/cpss. DeMarco, N., 2005. UK, Canada lead in used oil collection. In: Lube Report: Industry News from Lubes’n’Greases, No. 5. Environment. Waste Oils. www.ec.europe/environment/waste/oil index.htm. EPA, 1989. How to Set up a Local Program to Recycle Used Oil, Publication 530-SW89-039A. Hein, K.R.G., 2005. Future energy supply in Europe—challenge and chances. Fuel 84, 1189–1194. Kajdas, C., 2000. Major pathways for used oils disposal and recycling, part 1. Tribotest 7, 61–74. Keith, F. (Ed.), 1994. Handbook of Solid Waste Management. McGrow-Hill, Inc., New York. Lin, Q., Mendelssohn, I.A., 1998. The combined effects of phytoremediation and biostimulation in enhancing habitat restoration and oil degradation of petroleum contaminated wetlands. Ecol. Eng. 10, 263–274. Magiera, J., Markiewicz, M., Komorowicz, T., Gluszek, A., 2003. Used oils—a hazardous waste. Chem. Inz. Ecol. 10, 51–66 (in Polish). Mitsch, W.J., Jorgensen, S.E., 2003. Ecol. Eng.: a field whose time has come. Ecol. Eng. 20, 363–377.
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Mitsch, W.J., Jorgensen, S.E., 2004. Ecological Engineering and Ecosystem Restoration. Wiley, New York. Padma, S., Rao, A.G., Gavane, S.S., Ankam, M.F., Ansari, V.I., Nema, P.P., 2004. Performance evaluation of a green belt in a petroleum refinery: a case study. Ecol. Eng. 23, 77–84. Pawlak, Z., 2003. Tribochemistry of Lubricating Oils. Elsevier, Amsterdam. Prado-Jatar, M.A., Brown, M.T., 1997. Interfacial ecosystem with an oil spill in a Venezuelan tropical Savannah. Ecol. Eng. 8, 49–78. Product Stewardship (Oil) Regulations, 2000. Schedule 2. www.austlli.au. Rauckyte, T., Hargreaves, D.J., Pawlak, Z., 2006. Determination of heavy metals and volatile aromatic compounds in used engine oils and sludges. Fuel 85, 481– 485.
Robinson, B.W., Fleay, B.J., Mayo, S.C., 2010. The Impact of the Oil Depletion on Australia, www.aspo-australia.org.au/References/Abstract Lisbon Robinson.pdf. Stachowiak, G.W., 2007. Tribology in Australia. Tribology Online 2, 14–18. State of Utah, 1997. Department of Environmental Quality, Division of Solid Hazardous Waste, Used Oil Management Rules, October 16 (revised). State of Utah, 2005. Winter. DEQ, The Used Oil Drip. Used Oil Recycling, 2009. May18. www.oilrecycling.gov.au. U.S. SW-846, 1986. Test Methods for Evaluating Solids Waste, Physical and Chemical Methods. Vermont Agency of Natural Resources, 1996. Used Oil Analysis and Waste Oil Furnace Emissions Study. Vermont Department of Environmental Conservation, Waterbury, Vermont.
Contents lists available at ScienceDirect
Ecological Engineering journal homepage: www.elsevier.com/locate/ecoleng
Energy conservation through recycling of used oil Zenon Pawlak a,b,∗ , Wieslaw Urbaniak b , Tadeusz Kaldonski c , Michal Styp-Rekowski d a
Tribochemistry Consulting, Salt Lake City, UT 84117, USA Biotribology Laboratory, University of Economy, Garbary 2, 85-229 Bydgoszcz, Poland c Military University of Technology, Mechanical Engineering, Department of Tribology, Warsaw, Poland d University of Natural Sciences, Department of Mechanical Engineering, 85-789 Bydgoszcz, Poland b
a r t i c l e
i n f o
Article history: Received 14 February 2010 Received in revised form 8 August 2010 Accepted 23 August 2010
Keywords: Oil collection Recycling Ecological conservation Hazardous metals
a b s t r a c t This study concentrates on the investigation of energy and environmental benefits for used oil pertaining to its reuse through: (i) recovering the heating value of used oils in a combustion process and (ii) re-refining of used oil to produce fresh lube oil products. Tests were made with the used oil samples by ICP technique and the results were compared with standard requirements. We have found that the problems could successfully be solved through used oil management practices including collection centers, transporters, and processors by providing encouragement and financial support towards the re-refining industry. The novelty and value of our work lies in the conclusion that reformulation of motor oil results in lower levels of hazardous elements in used oils. © 2010 Elsevier B.V. All rights reserved.
1. Introduction The collection and recycling of used motor oil from our cars, trucks, motorcycles, boats, RVs, or lawnmowers is the best way to protect the environment from this hazard and conserve energy resources (Mitsch and Jorgensen, 2003, 2004). A used lubricant is not ecologically safe, but by its technical and physical properties corresponds to the requirements of beneficial reuse. Recycling keeps oil out of our groundwater supplies, thus protecting drinking water resources. Used motor oil can be reprocessed into fuel that can be used in furnaces for heat, or in power plants to generate electricity for homes, schools and businesses. Used motor oil can also be re-refined into lubricating oils that meet the same API specifications as virgin motor oil (American Petroleum Institute, www.recycleoil.org; Pawlak, 2003). The recycling (reprocessing, re-refining) allows recovery of mineral base oil, which is a valuable part in the production of lubricating oil used as a clean fuel and to create many petroleum-based products. One gallon (3.8 kg) of used oil can be re-refined into 2.3 kg of lubricating oil. For comparison, a 42-gallon (150 kg) barrel of crude oil typically contains only 1/2 gallon (1.9 kg) of lubricant-quality base oil (Lin and Mendelssohn, 1998). The composition of new lubricating oil consists primarily of a base oil which is a heavy end distillate of crude oil with the
boiling range of 325–600 ◦ C. It contains approximately 44% of straight chain and branched chain alkanes (primary C18 through C34 , 29% of cycloalkanes, 22% of aromatics, 4.2% of total aromatics and 3.2% of total naphthalene. Major additive classes (10–20 vol%) include corrosion and rust inhibitors, antioxidants, emulsifiers, detergents and dispersants, viscosity and color stabilizers, and anti-wear additives. The additives usually contain calcium, zinc, magnesium, molybdenum, phosphorus, sulfur and bromine compounds (Pawlak, 2003). The US federal government does not consider used oil that is destined for recycling a hazardous waste. There are three states, however, that have classified used oil as a hazardous waste (California, Massachusetts, and Rhode Island). These three states require a special handling of used oil. In all other states, used oil is handled like a typical household hazardous waste such as paints, varnishes, pesticides, and many cleaning products. Used oil in the USA is defined in Title 40 of the Code of Federal Regulations (CFR) part 279 as “any oil that has been refined from crude oil, or any synthetic oil, that has been used and as a result of such use is contaminated by physical or chemical impurities” (ATSDR, 1997). The following are examples of used oil: used lubricants, synthetic oils, transmission and brake fluids, refrigeration oils, compressor oils, hydraulic fluids, and heat transfer fluids. 1.1. Used oil specification
∗ Corresponding author at: Tribochemistry Consulting, Salt Lake City, UT 84117, USA. Tel.: +1 801 277 3936. E-mail addresses: [email protected], g.c.dotro@cranfield.ac.uk (Z. Pawlak). 0925-8574/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.ecoleng.2010.08.007
Used oil that has a flash point less than 38 ◦ C, dilution of contaminated used oil that contains PCBs or organic halogen compounds in excess of the maximum allowable concentrations
1762
Z. Pawlak et al. / Ecological Engineering 36 (2010) 1761–1764
Table 1 Used oil property and constituent limits. Property/constituent
Maximum allowable level, ppm
Arsenic Cadmium Chromium Lead Sulfur Polychlorinated biphenyls (PCBs)a Total organic halogens as chlorineb Flash point
5.0 2.0 10.0 100.0 Variable, mostly 1.0% Variable, mostly 2.0 1000 or 4000 38 ◦ C
a “Polychlorinated biphenyls” or “PCBs” means chlorobiphenyls that have the molecular formula C12 H10−n Cln in which “n ” is greater than 2. b “Organic halogen compound” means an organic chemical compound in which one or more halogen elements are incorporated.
prescribed in Table 1 is regulated (ATSDR, 1997; Magiera et al., 2003). The burning and marketing of used oil is subject to state and federal environmental regulations. Each state has adapted the federal EPA used oil management rules in Title 40 of the Code of Federal Regulations (CFR), part 279 and additional state used oil management requirements (Padma et al., 2004). The combustion conditions in most cement kilns can provide the safe incineration conditions for PCBs at a temperature exceeding 1200 ◦ C and the residence time of 4 s. Under federal regulations, used oil or fuel produced from used oil exceeding the limits set by US EPA can be burned for energy recovery only in industrial and utility boilers, industrial furnaces, hazard waste incinerators, and used oil-fired space heaters that meet specified provisions [CFR, section 279.11]. California regulates used oil as a hazardous waste. California generates more than 150 million gallons (495 million kg) of used oil annually and recycles just 59%. In California, US EPA allows the burning of used oil that is generated by the owner or operator of the unit or received from do-it-yourselfers in used oil-fired space heaters (ATSDR, 1997; Boughton and Horvath, 2004). This paper will discuss the most recent quality management of used oil collectors, re-recyclers and current trends, with suggestion on how to remove the major impediment in the way of achieving higher levels of lube oil re-refining in the US, EU and Australia. The used oil samples were tested and results compared with standards requirements.
2. Materials and methods 2.1. Analysis of used oil content in the United States of America Oil samples were collected from petroleum refinery and petrol stations in the years 2000 and 2009. Samples were digested with nitric acid and hydrogen peroxide using the hot block digestion procedure and EPA method was used to quantify metals (U.S. SW846, 1986; Rauckyte et al., 2006; Keith, 1994). Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used for analysis of total metals. A calibration standard was prepared from a multi-element standard. Three standards and one blank were used for calibration. The standard samples were prepared in a nitric acid/hydrochloric acid matrix, as specified in method 6010 (U.S. SW-846, 1986). The performance of the instrument was evaluated by determining the detection limit (DL) for each metal and several quality control (QC) parameters. The results of method reported level (MRL) values are (ppm): arsenic 0.5, cadmium 0.5, chromium 0.06, lead 0.30. During the analysis, several QC checks were performed to ensure that the ICP spectrometer was operating properly (see Table 2).
Table 2 Analytical data for used oil samples: halogen, pH, total metal concentrations and flash point values collected in the years 2000a and 2009b . Halogens, ppm
pH
520a 370a 480a 470a 390a 370b 343b 370b
8.6 7.3 8.5 7.9 8.1 8.2 8.4 7.8
Zn, ppm 1040 1110 1140 980 1230 820 677 690
Cd, ppm
Cr, ppm
2.8 3.0 3.3 4.2 5.9 2.1 2.8 2.7
3.9 4.2 5.8 3.4 6.9 2.7 2.9 3.1
Pb, ppm 102 70 140 105 93 53 33 47
Flash point, ◦ C 46 53 59 52 49 43 49 47
Quality control parameters: Standard reference material, SRM (95–104% recovery), continuing standard, CSTD (94–104%), lab spike blank, LSB (96–103%), lab spike blank duplicate, LSBD (95–104%), lab spike matrix, LSM (94–107%), lab spike matrix duplicate, LSMD (95–106%) were used as references for categorizations. Accuracy (% recovery) was determined as a ratio of LSB(found) and LSB(true) (96–104%), and precision (relative % difference (LSB − LSBD)/1/2(LSB + LSBD)); (3–8%).
3. Results and discussion 3.1. A review of used oil management practices in three regions of the world 3.1.1. Used oil program in the US The used oil program in the US has been decentralized and is under each state’s management and supervision. In Utah, for example, the state Department of Environmental Quality (DEQ) implemented effectively a program of collection and disposal of do-it-yourselfer (DIYer) used oils. Utah DIYer used oil collection represents only 4.5% (520,614 gallons) (1.7 million kg) of the total used oil collection in the US. The total quantity of used oil collected in Utah by registered used oil transporters in 2005 was 11,515,729 gallons (49 million kg) (State of Utah, 1997, 2005). Oil samples were analyzed for total metal content and halogens (see Table 2). Eight oil samples have surpassed regulatory limit for cadmium, which is 2.0 ppm. The good situation is in the case with chromium with a limit of 10 ppm. Three oil samples surpassed regulatory limit for lead which is 100 ppm. The lead concentrations determined in samples collected in 2009 (Table 2) are much lower than those reported in earlier studies (in the 1980s and 1990s) (Table 3) due to the change of unleaded gasoline standard in 1996. Lead has been blended with gasoline since the early 1920s. The EPA began working to reduce lead emission in 1973, gradually to one tenth of a gram per gallon by 1986. The average lead content in gasoline in 1973 was 2–3 g per gallon, or about 200,000 tonnes of lead per year (ATSDR, 1997). The used oil should not exhibit any hazardous characteristics (ignitability, corrosivity, toxicity and reactivity) that render waste hazardous. In addition, used oil must not contain polychlorinated biphenyls (PCBs) at a concentration at or above 5 parts per Table 3 Concentration of potential hazardous heavy metals, total halogens in used oils burned as a fuel in the 1980s and 1990s in the United States (Vermont Agency, 1996). Analyte
Mean concentration (ppm) in the 1980s
Concentration range (ppm) in the 1990s
Virgin fuel oil (ppm)
Arsenic Barium Cadmium Chromium Lead Zinc Halogens
20 137 4.0 38 555 707 5500
Not analyzed 1–7 0.3–7 2–7 20–146 570–2370 100–440
0.06 13 1.0 4.1 4.1 2.0 5.7–7.8
Z. Pawlak et al. / Ecological Engineering 36 (2010) 1761–1764 Table 4 Production of lubricating oil, its collection and loss to the environment in the US, EU and Australia. Country
Production
Used oil collection
Loss to the environment
USA
4.5 billion kg
Australia
465 million kg
EU
5 billion kg
780 million gallon, or 2.6 billion kg 180 million kg 2.5 billion kg
200 million gallons, or 660 million kg 54–88 million kg 100 million kg
million (ppm), or halogens (e.g., compounds containing chlorine, bromine, and fluorine) above 1000 ppm. Used oil containing more than 1000 ppm halogens is presumed to be mixed with halogenated hazardous wastes and must be managed as such, unless the generator of the waste can demonstrate otherwise (Vermont Agency of Natural Resources, 1996), (see Table 3). Table 3 shows the distinct decrease in barium, chromium, lead and halogens content for used engine oils for the last two decades. 3.1.2. Oils collections in the European Union The EU15 Waste Oil Directive 75/439/EEC, as last amended by Directive 2000/76/EC, is designed to create a harmonized management for used oils. The Directive also aims to protect the environment against the harmful effects of illegal dumping and of treatment operations. The EU consumed in 2003 roughly 5 billion tonnes of lubricating oils a year (see Table 4). Some half of that quantity purchased would become waste oils (the rest is lost either during use or through leakages, etc.) That leaves us with approximately 2.5 million tonnes of waste oil to manage every year in the EU. The average collection rate in the EU15 is around 81% (Magiera et al., 2003; Kajdas, 2000; Environment, www.ec.europe; Hein, 2005; Prado-Jatar and Brown, 1997). 3.1.3. Used oil recycling across Australia Australian lubricants are manufactured from crude oil imported from the Middle East, because domestic crude oils are not suitable for making base stock. Australia’s annual consumption of virgin lubricant is around 465 million kg, while about 180 million kg of used oil is recovered. Around 27–36 million kg of used oils are stockpiled across Australia (Used Oil Recycling, 2009; CPSS, 1999; Stachowiak, 2007). More than 400 oil collection points have been set up in Australia and further 300 are under construction. Around 75% of collected
Fig. 1. Comparison of used oil collection and lost to environment.
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used oils are reused as a burner fuel in cement and lime kilns, furnaces and industrial burners. At present, only one company, Environmental Oil in Victoria state, converts around 20% of used oil into a product that meets the current specification for diesel. Less than 3% of the recovered used oils are re-refined to base lubricating oils (CPSS, 1999). The Product Stewardship for Oil Program (PSOP) was introduced in 2001 by Australian Government to provide incentives to increase used oil recycling. The Government has spent AU$34.7 million over 7 years to support the implementation the PSOP. The additional benefit ceased after 30 June 2009 (DeMarco, 2005; CPSS, 1999; Product Stewardship, 2000, www.austlli.au; Robinson et al., www.aspo-australia.org.au). 4. Conclusions The US, EU and Australia provide financial incentives to motivate the re-refinery industry to gain the number of operators to increase production capacity. The study identified an option to integrate various industry representatives including used oil collectors and transporters, used oil processors, including used oil refiners, representatives of the used oil consuming group, and automotive dealers associations. The study of energy and environmental requirements for used oil concerns deals with the heating value in the combustion process, and re-refining of used oil. The oil can therefore be reused in producing fresh lube oil products. Currently in the USA, 780 million gallons (2.6 billion kg) of used oil are estimated to be recycled each year. Approximately 83% of this amount is burned and 17% is re-refined, while in the European Union these figures are 77% and 33%, and in Australia 97% and 3%, respectively. A comparison of used oil collection and of oil lost to the environment in the US, EU and Australia is shown graphically in Fig. 1. Compared to the USA, it appears that most European countries are more advanced in the area of used oil recycling and reuse, with two to three times as great processing capacity. Acknowledgement This work was partially funded by the University of Economy in Bydgoszcz. References American Petroleum Institute (API), 2010. Used Motor Oil—Collection and Recycling, www.recycleoil.org. ATSDR, 1997. Agency for Toxic Substances and Disease Registry. Toxicological Profile for used Mineral-based Crankcase Oil. U.S. Department of Health and Human Services, Atlanta, GA. Boughton, B., Horvath, A., 2004. Environmental assessment of used oil management methods. Environ. Sci. Technol. 8, 353–358. CPSS, 1999. Comprehensive Product Stewardship System (CPSS) for Waste Oil—Discussion Paper, Environment Australia, www.oilrecycling.gov.au/cpss. DeMarco, N., 2005. UK, Canada lead in used oil collection. In: Lube Report: Industry News from Lubes’n’Greases, No. 5. Environment. Waste Oils. www.ec.europe/environment/waste/oil index.htm. EPA, 1989. How to Set up a Local Program to Recycle Used Oil, Publication 530-SW89-039A. Hein, K.R.G., 2005. Future energy supply in Europe—challenge and chances. Fuel 84, 1189–1194. Kajdas, C., 2000. Major pathways for used oils disposal and recycling, part 1. Tribotest 7, 61–74. Keith, F. (Ed.), 1994. Handbook of Solid Waste Management. McGrow-Hill, Inc., New York. Lin, Q., Mendelssohn, I.A., 1998. The combined effects of phytoremediation and biostimulation in enhancing habitat restoration and oil degradation of petroleum contaminated wetlands. Ecol. Eng. 10, 263–274. Magiera, J., Markiewicz, M., Komorowicz, T., Gluszek, A., 2003. Used oils—a hazardous waste. Chem. Inz. Ecol. 10, 51–66 (in Polish). Mitsch, W.J., Jorgensen, S.E., 2003. Ecol. Eng.: a field whose time has come. Ecol. Eng. 20, 363–377.
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