Thesis (M.S.)--Mechanical Engineering, Georgia Institute of Technology, 2005. / Jiri Janata, Committee Member ; Shreyes Melkote, Committee Member ; Steven Danyluk, Committee Chair. Includes bibliographical references.

M.Sc. / It is estimated that there are approximately 6.9 million vehicles operating on South African roads, four million (58%) of which represent passenger cars. (Mbendi, 2002a). The number of vehicles operating on national roads increase annually. For motor vehicle engines to perform optimally, among other components, they require engine oil. Nationally in 2002, approximately 40 million litres of motor oil were sold at service station forecourts. For the same period, Gauteng motor oil sales exceeded 17.5 million litres while 76% of these sales occurred in Johannesburg (Maneveld, 2003b). When motor oil is poured into an engine there is always an amount of oil that remains in the container. In this study the author quantifies the amount of unused motor oil that is discarded into the environment via the containers that carry it and makes an assessment of the associated environmental implications. In the South African context, no documented data regarding this problem exists. Chapter one provides the background and motivation to the study, an explicit description of the problem being researched, objectives of the research, the study area and a brief description of the research methodology. This chapter defines the parameters within which the research took place. Chapter two briefly describes the South African oil and lubricants industry. It also focuses on lubricant manufacture, blending, composition, use and properties of lubricants. Chapter three details the research methodology and data collection procedures. This is followed by an analysis of the pilot and main study encompassing statistical interpretation and synthesis. Graphical and photographic illustrations are used. Conclusions were reached on the basis of factual information. Chapter four collates the information from previous chapters, which enables the author to make projections and quantify the amount of unused oil discarded into the environment. An assessment of the associated environmental implications is then determined. In the last chapter, limitations of the study are discussed. This is followed by concluding statements, proposals for further research and recommendations to address the research problem.

Bibliography: pages 46-50. / A sequential atomic emission spectrometer, using a low power (1,7 kW) argon-cooled inductively coupled plasma (ICP) system, was used for the determination of wear metals and additives in lubricating oils with xylene as solvent. The modified Simplex method was applied to establish the optimum experimental parameters for 21 individual spectral lines. The optimization was applied to single element analysis on the basis of net signal-to-background ratio (SBR) using the standard cross flow nebulizer and then repeated using the high solids Babington-type nebulizer. Weighted compromise conditions were calculated resulting in a maximum loss of 50% in the SBRs of the individual elements. These conditions result in an analytically useful plasma that gives low detection limits and high sensitivities for the analysis of metals in lubricating oils. Analytical parameters such as detection limit and analytical range for the analysis of 17 elements present in lubricating oil as wear metals or contaminants and 4 other elements present in the most common lubricating oil additives were determined. The detection limits reported here for oil in xylene are of the same order as the published limits for aqueous and for oil-in-MIBK solutions. However, the most valuable property of the ICP-AES was found to be the astounding analytical range which allows determinations to be made over a large concentration range without the need for serial dilutions. The effect of sample preparation was investigated by employing ultrasonic agitation prior to withdrawing the used oil from the sample vial. An upward trend was found in the element concentrations from manual shaking of the oil to ultrasonic agitation, indicating a particle distribution effect. Finally, the technique was tested successfully by analysing an NBS reference standard and by participating in several "round robin" used oil analyses. ICP-atomic emission spectrometry can be successfully applied to the analysis of metals in lubricating oils with a speed, accuracy and precision which at least equals, and even improves upon any other of the established techniques.

M.S.

The object of this thesis was to investigate some of the factors that night effect the oil film performance between piston rings and cylinder walls. An apparatus was constructed to measure the instantaneous changes in resistance across the oil film. A piston ring of an air-cooled single cylinder engine was insulated from the rest of the piston using Teflon. A bridge circuit was used to feed the unbalanced signals to an oscilloscope. The traces on the oscilloscope were recorded by means of an Polaroid-Land recording camera. An external motor having a speed control system was used to drive the engine. It was found from this investigation that the lubrication could be improved by increasing the engine speed and oil viscosity. More metallic contact was found when the engine was under its own power. The results also showed that the breakdown of oil film occurred when the oil temperature was increased. The experimental results indicated that the piston ring and the cylinder wall were never separated by lubricating oil at dead centers. The breakdown of oil film occurred at these positions in every case. / Master of Science

M.Tech. (Mechanical Engineering) / This study investigated process development of recovering base oils from waste lithium based lubricating grease using a novel combination of thermal degradation in an aqueous caustic solution and solvent extraction. Lubricating greases consist of a thickening agent dispersed in mineral or synthetic oil, forming a colloidal suspension [1]. Large and increasing volumes of used lubricating oil and grease are produced each year and are considered hazardous wastes. During operation, grease suffers mechanical and thermal degradation [2]. Subsequently, it is regarded as waste and it must be disposed. The waste oil should be collected and recycled not only to prevent the environmental pollution but also to preserve natural resources. Solvent extraction is the preferred method to recycle waste lubricants as it is cost-effective and requires no further purification of the product [3]. The influence of extraction temperature, agitation strength, extraction time, degrading agent concentration, degrading agent-to-grease and solvent-to-sludge mixing ratios on base oil recovery from waste lubricating grease was investigated. This study further optimised the process by studying the influence of various degrading agents (LiOH, NaOH and KOH) and solvents (n-hexane, toluene, heptane, butane, hexanol and acetone) on oil recovery. Oil recovery was enhanced by increase in both extraction temperature, time and agitation speed. The optimum extraction time was found to be 12 minutes. KOH was found to be the optimum degrading agent compared to LiOH and NaOH. Oil recovery also increased from 8.04% to 36.87% with increase in KOH m/m from 5% to 30%. The recovery also increased with an increase of solvent-to-sludge ratio up to 1:6. n-Hexane gave the highest recovery of 74.39% while acetone gave the lowest of 7.43%. A solvent recovery of 82.6% to 88% was obtained through fractional distillation. The study also investigated the differences between virgin and recycled oil using atomic absorption (AA), inductively coupled plasma (ICP) and Fourier transform infrared radiation (FTIR). Rheological studies of waste grease derived oil (WGDO) were also performed. ICP results showed traces of some elements such as Fe, Cu, Si, Ni and Al at a concentration of less than 0.9 mg/L. Oxidation was observed to occur at a band length of 1716 cm-1 while additives were identified at 1670 - 1725 cm-1. The oil viscosity slightly increased with increasing shear rate at temperatures between 60°C and 120°C. The shear rate was varied from 200 to 1000 1/s, with a viscosity convergence at 100°C. A financial economic model was applied to investigate the feasibility of the recycling technology. For 800 kg/day treatment plant, an investment of R 6,031,304.27 is required with a potential return on investment of 40%. Recovery was found to be favourable option compared to landfilling as it offers both economic and environmental benefits.

Thesis (M.S.)--University of Akron, Dept. of Mechanical Engineering, 2008. / "December, 2008." Title from electronic thesis title page (viewed 12/9/2009) Advisor, Jiang John Zhe; Faculty Readers, Joan Carletta, Dane Quinn; Department Chair, Celal Batur; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.

M. Tech. Chemistry. / Methods developed for the analysis of used oil can play a vital role in monitoring the condition of engines and may help to improve overall equipment effectiveness. Quantification of trace elements in used lubricating oil forms a vital part in monitoring engine conditions and impact on the environment. The main objective of this work is to investigate methods used for the accurate determination of trace elements in lubricating oils. In this study, inductively coupled plasma-optical emission spectrometry (ICP-OES) was used for the determination of trace elements (Ag, Ba, Cu, Mn and Ni) in lubricating oils.

Investigations of new applications of the inductively coupled plasma (ICP) for analytical atomic emission spectroscopy are performed. Research efforts are focused in three major areas: emissions below 185 nm, analysis of wear metals in lubricating oils and use of the ICP as a selective detector for high performance liquid chromatography (HPLC). A unique plasma coolant tube containing a side arm which allows direct observation of the discharge is used to investigate emissions in the vacuum ultraviolet (VUV) spectral region between 120 and 185 nm. Emissions from elements which do not emit radiation in the visible region are observed. Oxygen emissions at 130 nm, nitrogen at 149 and 174 nm and carbon at 155 and 165 nm make up the background spectrum. These elements are present as impurities in the argon gas used to sustain the ICP discharge. Fifteen emission lines from bromine are observed. Those at 153 and 163 nm are the most intense. Sulfur also has fifteen emission lines and chlorine has nine in this region of the spectrum. The VUV region is found useful for observation and potential analysis of many elements. A heated sample introduction system attached to a Babington nebulizer is investigated as a means to aerosolize lubricating oils for introduction into the ICP. This allows direct analysis of wear metals in oil samples without requiring the usual sample dilutions. Several commercial brands and weights of motor oil are spiked with iron in order to evaluate this system. Heating the oil as it enters the nebulizer is found to increase the nebulization efficiency as much as sixtyfold in some cases. Differences in nebulization efficiency due to viscosity are almost entirely eliminated through the application of heat. A linear calibration curve extending three orders of magnitude from a detection limit of one ppm iron is determined. The ICP is used as a selective detector for HPLC. Nucleotides separated by anion exchange chromatography are determined in the ICP by observing phosphorus emissions. Methanol and acetonitrile used for reverse phase HPLC are successfully run in the IPC. The method is evaluated by using the ICP to determine phosphorus in compounds separated by using reverse phase conditions. The HPLC is used to separate organic interferences from several silicone samples using reverse phase conditions allowing the ICP to accurately analyze silicon content.

Thesis (M.S.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains xi, 150 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 97-101).