National Bureau of Standards Special Publication 556. Proceedings of CURRENT EPA VIEWS ON AMBIENT AIR LEAD STANDARDS J. S. Cooper Strategies and Air Standards Division U.S. Environmental Protection Agency Because the author's written presentation was not received by the specified publication deadline, it will not be included in these proceedings. National Bureau of Standards Special Publication 556. Proceedings of a Workshop on Measurements and Standards for Recycled Oil – II held at NBS, Gaithersburg, Maryland, November 29 and 30, 1977. (Issued September 1979) AN UPDATED LOOK AT THE FUEL POTENTIAL OF WASTE AUTOMOTIVE OIL Peter D. Spawn and Paul F. Fennelly GCA/Technology Division Bedford, Massachusetts 01730 Abstract 1 Cer Under an Environmental Protection Agency contract, GCA/Technology Division evaluated the technical, economic, and environmental feasibility of reusing automotive waste oil as a fuel [1] The study found that the total quantity of automotive waste oil generated annually represents slightly less than 0.5 percent of total U.S. fossil fuel production. tain precautions are necessary to prevent potential problems with boiler operation and increased levels of stack emissions, notably particulates and lead. Blending small quantities of untreated waste oil with virgin stocks appears feasible for large utility and industrial boilers, while some pretreatment of oil was found desirable for smaller boilers. The first portion of the paper discusses major findings of this study. The second portion of the paper addresses methods which can be used to evaluate local or Statewide barriers and problems which hinder effective reuse of waste oil. Such a program is an essential step towards establishing an effective local or regional policy for reuse of waste oil. Potential Supply and Marketability of Waste Oil as Fuel The quantity of waste lubricating oil potentially available for reuse as fuel was estimated by GCA based on regional per capita consumption figures [2]. Table 1 indicates that nationwide approximately 715 million gallons of automotive and 330 million gallons of industrial oils are potentially available for reuse. Industrial lubricants, roughly 30 percent of potential waste oil supply, were found to vary widely in physical properties and are not as readily reprocessed to fuel as automotive waste oil. For this reason, GCA focused on reuse of waste automotive lubricants as fuel. Underlined numbers in brackets indicate the literature references at the end of this 1 paper. The quantity of waste automotive oil available for reuse represents less than 0.5 percent of domestic fossil fuel production, and about 5 percent of total oil consumed by domestic steam-electric power plants. Although the waste oil supply is concentrated in high-density population centers, the regularity and quality of this supply is variable. Consequently, it will be most effective to reuse waste oil as supplemental or reserve fuel until longer-term systems are developed to promote supply regularity through improved collection, storage, and distribution. To assess the demand for waste oil as fuel, questionnaires were distributed to potential electric utility and industrial users. These data were supplemented by field site visits and personal interviews. Electric power generation consumes about 25 percent of domestic energy production and represents a significant potential market for waste oil fuels. Several power plants were found to be combusting waste oil routinely or testing waste oils for routine use. Eighty-six percent of the 68 electric utilities responding to the GCA survey felt some form of waste oil could be used at their facilities. Response to GCA's survey by industry was less positive towards waste oil reuse as fuel. Industrial sources are diverse in fuel requirements and requested a more detailed analysis of fuel composition and potential adverse affects on a particular process. In most regions of the country, a network of private waste oil collection firms is currently collecting waste oils from automotive service stations. A recent GCA study of hazardous waste generation [3] found that roughly 50 percent of waste oil collected in Massachusetts is reused as fuel, while 23 percent is re-refined as lube oil. Waste oil collectors are currently paying service stations $0.02 to $0.07 per gallon for the oil and selling untreated or minimally treated oil to commercial boiler facilities for about $0.20 to $0.30 per gallon. This price structure compares locally to $0.35 to $0.40 for distillate and $0.30 to $0.35 for residual fuel oils. Institutional/Legal Factors Influencing Waste Oil Reuse Institutional and legal factors also influence reuse of waste oil as supplemental fuel. State waste oil management programs may either aid or hinder reuse as fuel. For example, Nebraska stipulates a maximum water and solids content and prohibits presence of highly flammable aromatic hydrocarbons in any waste oil reused as fuel. Local and Federal air pollution standards may limit quantity of waste oil combusted. Relatively high ash content of untreated waste oil can increase particulate emissions. Blending waste oil with residual oil can result in decreased sulfur oxide emissions since waste oil is relatively free of sulfur. Most power plants are restricted in percent sulfur allowed in fuel, and blending with waste oil could help meet sulfur regulations. Waste Oil Composition and Technical Feasibility of Reuse as Fuel Waste automotive oils also contain small amounts of transmission fluids, differential gear lubricants, hydraulic oils, and solvents. In addition, some or all of the following substances are commonly present in the waste oil mixture: (1) functiona oil additives; (2) iron "fines" from engine fretting and wear; (3) gasoline components oxidized materials, atmospheric dust, and combustion products transferred to the oil via piston "blowby;" (4) sedimentary materials which were formerly internal engine deposits; and (5) water and other contaminants introduced to storage tanks. GCA summarized physical and chemical properties of waste oil and waste oil/virgin oil blends, based on published and in-house data. Tables 2 and 3 summarize physical and chemical properties of untreated waste oil, virgin distillate and residual oils, and various blends of waste and virgin oils. Technical impacts of using blended oils as a boiler fuel were assessed based on these data, results of the survey questionnair and interviews with potential utility and industrial users of waste oil products. Viscosity of a 10-percent waste oil/distillate oil blend was found to be three times that of virgin distillate oil. However, centrifugal pumps normally used for distillate oil are capable of handling the 340 centis toke viscosity of a 10-percent waste oil/distillate oil blend. Waste oil/residual oil blends of 10 percent are somewhat less viscous than virgin residual oil. Pour point of 10-percent waste oil/distillate oil and waste oil/residual oil blends is slightly less than pour points of the respective virgin fuels. Waste oils contain pour point depressants to prevent solidification at cold temperatures. |