United States Environmental Protection Agency National Risk Management Research Laboratory Cincinnati, OH 45268 Research and Development EPA/600/SR-96/092 September 1996 AEPA Project Summary Waste Oil Reduction for Diesel Engines Todd Sigaty, Carl Reller, and Daniel Middaugh This project reduced waste oil from diesel engines at remote sites in Alaska by extending oil change intervals us- ing bypass filters and a closed-loop reblending process in connection with portable field monitors and laboratory analysis. Incidents of normal and ab- normal oil degradation were recorded and correlated between field and labo- ratory tests. A quality assurance pro- gram evaluated data precision and ac- curacy. Waste oil from diesel engines repre- sents the greatest environmental health problem in Alaska, especially in remote areas where disposal/recycling options are nonexistent. Results of this project showed that small, isolated communi- ties can reduce the amount of waste oil generated at the source with techniques that are easy to implement and inex- pensive. However, they depend prima- rily on operator interest in closely moni- toring the engine because degradation levels need to be determined individu- ally for each engine and oil type by establishing baseline data. This Project Summary was developed by EPA's National Risk Management Research Laboratory, Cincinnati, OH, to announce key findings of the re- search project that is fully documented in a separate report of the same title (see Project Report ordering informa- tion at back). Introduction This study was a cooperative effort be- tween EPA's National Risk Management Research Laboratory (NRMRL) and the Alaska Health Project (AHP), the central site of the project. The AHP, located in Anchorage, is a nonprofit organization of- fering technical assistance on pollution prevention and waste reduction. The goal of this project was to test different tech- nologies to reduce waste oil at remote sites in Alaska. The generation of energy is critical to remote villages, marine vessels and mili- tary bases throughout Alaska. The use of diesel generators to provide that energy results in large quantities of used oil, part of the more than one billion gallons of waste oil generated annually in the U.S. The U.S. Environmental Protection Agency (EPA) is concerned about the quantity of waste oil improperly disposed of each year because of its threat to the environment and its cost to remediate. Carefully managed, used oil retains its economic value, but many small commu- nities have neither the experience nor the knowledge to evaluate the condition of used oil or to determine a reasonable means of recycling. Consequently, much of the accumulated used oil is transported many miles at substantial cost, and indis- criminate dumping is common. Current filtration technology may be able to pro- cess used oil on site, providing a re- cycled oil that meets specifications for burning. Objectives for this project were to determine (1) whether engine manufacturer's recommendations for oil change intervals (OCIs) could be in- creased with field and laboratory mea- surements of oil degradation; (2) whether bypass filters are effective in extending oil drain intervals; (3) whether the closed-loop process is efficient and af- fordable in eliminating waste oil; and (4) whether these technologies can be easily implemented by small, isolated communi- Printedon Recycled Paper ------- ties. The project also evaluated whether technologies for extending oil life would concentrate polynuclear aromatic hydro- carbons (PAHs) at levels hazardous to the health of oil handlers. Procedure The sites selected for this project were stationary electric generating plants located in rural areas ranging from the Arctic north, through the Aleutian Islands, to the tem- perate rain forests of Southeastern Alaska. Other participants were a marine vessel and a federal hydroelectric facility. Phase I—extension of oil change intervals using analysis alone—was conducted over an 11-month period at 13 Alaskan sites on 20 diesel engines ranging from 23 to 3,000 hp. Participants were asked to gradually extend OCI based on field monitoring and laboratory analysis alone. In Phase II—extension of OCls through the use of bypass filters—data was com- plied from nine diesel engines at four sites. Filtration is defined for this project as the physical separation of liquids and solids by means of centrifuges and media filters, the two technologies commonly used in bypass filters. Oil is commonly filtered be- tween oil pump and engine by diverting 100% of the oil through a "full flow" filter able to remove large particles (greater than 20 microns). Full flow filters are inef- ficient at removing liquids (such as water, unbumed fuel or acids) and small metal contaminants below 20 urn. Bypass filters remove particles in the below-20-micron range by intercepting about 10% of the main flow of oil. The following filter sys- tems were selected for this project based on product quality and information, expe- rience and cost: Gulf Coast, Spinner, Purifiner, Harvard and Power Plus. Used oil samples were taken from the engines as often as every two days and tested by the engine operator onsite and by the project manager at the AHP office. To monitor oil quality in the field a portable battery-powered comparative dielectric analyzer (CDA) was used. This equipment determines the deterioration in motor oil from continued use. By measuring any deviation of the dielectric constant between fresh and used oil, it indicates the overall condition of the oil and helps determine the optima) oil change interval. For this project, the LubriSensor Model N1-2B was selected based on its cost, usability and documentation ability. After each sample was tested in the field it was sent to Ana- lysts Laboratory in Oakland, CA, for analy- sis of the physical and chemical proper- ties of the oil. This lab was chosen after a national search on the basis of its quality manuals, experience and commercial avail- ability. For this project, Analysts tested each sample for 21 metals and the total base number (TBN). TBN is an indicator of oil buffering quality, i.e., the quantity of hydrochloric acid, expressed in terms of the equivalent number of milligrams of potassium hydroxide required to neutral- ize all the basic constituents present in a one-gram sample of oil. The TBN indi- cates relative change in oil regardless of color or other properties. This project chose to analyze TBN and CDA as the best indicators of oil quality. Lab results were sent to AHP and then to the engine op- erator. With every fifth used oil sample, a quality control sample was sent to the lab. In Phase III—the elimination of waste oil through reblending and recycling—a closed-loop process was used on a sta- tionary engine and a marine engine at two different sites. The closed-loop process is one in which the oil is removed from the engine at a set rate and blended in the fuel tank at a varied ratio of oil to fuel. In addition to eliminating the need to dis- pose of v/aste oil, the quality of the fuel is increased. For this project, the Power Plus Smart Tank Model ED3500S was selected for the stationary engine; the Volvo MD11C marine engine used its own blending sys- tem constructed onsite. Oil was removed at the rate of 1.3 oz/engine hr and blended in the fuel tank at 2% oil : fuel. This removal rate uses the same amount of oil as changing the oil once every 150 hr. Upon good analysis, the removal rate was reduced by 50% to .65 oz/hr, and the blend to 1% oil : fuel, a removal rate equal to changing the oil once every 300 hr. During the project, the methods or inde- pendent variables were oil analysis and filtration systems. Dependent variables were oil change intervals and cost. Re- sults from samples collected at each site were compiled on data sheets and en- tered into a database. To ensure accu- racy, the data were entered twice by two separate individuals. Each data set was cross checked for discrepancies. All mea- surements, data gathering equipment and data generation activities were routinely assessed for precision, accuracy, com- pleteness and detection limits. Results; and Discussion Results of the data were plotted on graphs; several examples are shown here. Figure 1 shows the CDA readings against engine hours on oil for each of the bypass filters on engine No. 5. A higher CDA rating can be an indication of possible oil contamination. The control plot is an ex- tension of oil drain interval without a by- pass filter. On this engine the control samples had lower CDA readings than samples from the Spinner filter. The samples from the Purifiner filter had a lower CDA reading than the Spinner or control samples. All samples on this en- gine were able to extend their OCI to over 800 hr without any CDA readings indicat- ing oil contamination. Figure 2 shows CDA readings against engine hours for the con- trol used-oil samples and the Gulf Coast used-oil samples on engine No. 8. A higher CDA reading can be an indication of pos- sible oil contamination. The control plot is an extension of oil drain interval without a bypass filter. This figure shows that on this engine the control samples had lower CDA readings than the Gulf Coast samples, but that both sets of used-oil samples were able to be extended to over 1200 hr without any CDA readings indi- cating oil contamination. Figure 3 shows the CDA readings against engine hours for the control used oil samples and the 1.5% oil: fuel blend samples on the Volvo MD11C engine within a 95% confidence level. A higher CDA reading can be an indication of possible oil contamination. The control plot is an -extension of oil drain interval without a by-pass filter. The blend is a closed-loop process where used oil is blended with incoming fuel. This figure shows lower CDA ratings than the control samples on this engine. The blend samples were extended to over 200 hr without CDA readings indicating any oil contamination. (Manufacturer's recommen- dation is 50 hr.) The control samples were able to extend the oil to over 350 hr but had CDA readings indicating possible oil contamination. Figure 4 plots the com- plete range of data points and extends the data to the point where TBN level would reach zero on the Volvo MD11C engine. The figure shows a direct relation- ship between CDA and TBN readings with a 95% confidence level extended to over 1000 hr. This ability to predict the TBN level aids the engine operator because lab analyses take time and are costly. Conclusions This study focused on answering the objectives stated in the Introduction. The study finds that: 1. Oil change intervals can be extended beyond engine manufacturers' warranty recommendations without oil degrada- tion. To ensure protection of the engine while extending the OCI, field monitor- ing of oil condition is recommended. CDA data collection is easy, inexpen- ------- o> T3 o 200 400 600 800 1000 1200 Hours on Oil Figure 1. Bypass filter vs. control samples CAT 3512, engine No. 5. 0.0 200 400 600 800 1000 1200 1400 Hours on Oil Figure 2. Bypass filter vs. control samples CAT 3516, engine No. 8. ------- 3.0 2.5 2.0 I 8 oc O 1.5 1.0 0.5 ,''/' ^ 95% Confidence 0 50 Figure 3. 1.5% all: fuel blend engine, Volvo MD11C. 10 100 150 200 250 300 350 Hours on Oil 4| z & I 200 400 600 800 1000 1200 1400 1600 1800 2000 Hours on Oil Figure 4. Control extended to zero TBN engine, Volvo MD11C. ------- sive and a good indicator of oil degra- dation. There is a consistent relation between CDA readings and TBN levels in measuring oil degradation. However, each engine and situation is unique. Therefore, OCI extensions based on CDA response should be correlated with laboratory analysis for each engine, lu- bricating oil and fuel type. The prob- ability of oil decreasing TBN increases between 800-2000 hr and at a CDA reading of 3.0-6.0 for the engines tested in this study. 2. Oil samples from stationary diesel en- gines that used bypass filters showed no less oil contamination than control samples. Other studies have revealed that oil change intervals can be ex- tended when using bypass filters, but they had no control data. The Power Plus used-oil blend unit limits oil degra- dation and eliminates waste oil for sta- tionary diesel engines. The Power Plus unit is efficient, effective and afford- able. Based on a 5,000 hr/yr opera- tional period, engines at one site (Unalaska) saved over 2,000 gal/yr. One engine at Unalaska, and the engine at Seward, eliminated waste oil while us- ing the Power Plus re-blend technol- ogy. Based on a 5,000 hr/yr opera- tional period, engines at one site (Unalaska) saved over 2,000 gal/yr of lubricating oil. 3. Small isolated communities can reduce the amount of waste oil they generate. However, the ability to do so is based primarily on operator interest and de- sire to closely monitor the engine. This increased attention is needed because degradation levels need to be deter- mined individually for each engine and oil by establishing baseline data. The study further found no significant health hazard from PAHs in the used oil sampled resulting from oil exchange inter- vals or burning used oil. The full report was submitted in partial fulfillment of Contract Number CR-817011-01-0 by the Alaska Health Project under the sponsorship of the U.S. Environmental Protection Agency. •&U.S. GOVERNMENT PRINTING OFFICE: 1996 - 750-001/41051 ------- ------- ------- Todd Slgaty, Cart Reller, and Daniel Middaugh are with Alaska Health Project, Anchorage, AK 99501. Paul Randall is the EPA Project Officer (see below). The complete report, entitled "Waste Oil Reduction for Diesel Engines," (Order No. PB96-196779; Cost: $28.00, subject to change) 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: National Risk Management Research Laboratory U.S. Environmental Protection Agency Cincinnati, OH 45268 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-96/092 ------- |