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Environmentally friendly fuels and lubricants research on hydraulic fluids, engine oils, greases and industrial applications is of interest to government agencies and manufacturers of equipment, engines and vehicles. The key to increasing the use of renewable natural resources is developing fluids of equivalent performance to petroleum base products, at an acceptable product cost. The well known drawbacks of vegetable oils are oxidation stability and low temperature properties. This study compares commercial fluids and laboratory formulations as to their rheological properties and uses different approaches to solve both the low temperature and the oxidative stability problems. Frictions and wear characteristics of the fluids are evaluated and several fluids are compared laboratory bench tests.

Interlaboratory comparisons of extraction and chemical characterization are reported for exhaust particulate from heavy-duty diesel engines, typical of the 1980s. This study is the final of a series conducted by member companies of the Coordinating Research Council on methods and measurements to expand knowledge about unregulated constituents of diesel-engine exhaust. Exhaust particulate from heavy-duty diesel engines of the 1980s averaged about 25 wt% extractable by methylene chloride. In engine-to-engine comparisons, the extractable fraction correlated with the ratio of total engine hydrocarbon to nonextractable carbon particulate. These comparative studies demonstrate methods for monitoring changes in the composition of diesel particulate that may occur as stringent emission standards are implemented in the 1990s.

A four-ball wear test has been designed and tested with a series of petroleum based hydraulic fluids. This test procedure comprises a sequence of three 30 minute test segments designed to evaluate “wear in,” steady state wear and the effect of antiwear films produced in the first two parts of the test. Excellent repeatability of this sequential testing has been established. The wear properties of formulated fluids have been shown to be a function of system temperature and bearing load. A series of formulated mineral oil base lubricants that have been evaluated extensively in heavy-duty industrial hydraulic equipment have also been evaluated in a laboratory pump test system and the sequential four-ball wear test. A correlation developed for the heavy-duty industrial hydraulic systems with the laboratory pump test system has been extended to the four-ball wear tester sequential runs under specific load and temperatures.

The CRC-APRAC CAPI-1-64 Odor Panel was formed in 1973 to assess an instrumental measurement system for diesel exhaust odor (DOAS) developed under CRC-APRAC CAPE-7-68 by Arthur D. Little, Inc. Four cooperative studies were conducted by nine participating laboratories using common samples. The objectives of these studies were to define the DOAS system variables and to validate and improve the sampling and collection procedures. A fifth study, serving as a review of each analysis step, showed that analysis of common derived odorant samples could be conducted within acceptable limits by the participating laboratories. Three in-house sampling system design and operating parameter studies were conducted simultaneously with the cooperative work. The combined findings from the in-house and cooperative studies led to a tentative recommended procedure for measuring diesel exhaust odor.

This is the fourth in a series of tests conducted as a Coordinating Research Council cooperative program to evaluate the measurement methods used to analyze diesel exhaust gas constituents. A multi-cylinder engine was circulated to 15 participants who measured emissions at three engine conditions. All 15 participants measured nitric oxide and carbon monoxide with several laboratories measuring nitric oxide by both NDIR (Non-Dispersive Infrared) and CHEMI (Chemiluminescence). Some participants also measured carbon dioxide, nitrogen dioxide, oxygen, and unknown span gases. The test results are compared with the Phase III cooperative tests which involved simultaneous measurement of emissions by participants. The precision of the results was poorer in Phase IV than Phase III.

A Coordinating Research Council cooperative program was conducted to evaluate the measurement methods used to analyze nitric oxide and carbon monoxide in diesel exhaust. Initially, a single-cylinder test engine was circulated among participants with poor results. Tests were then conducted at one site using a multicylinder diesel engine. Six organizations participated in the program. Exhaust analyses were conducted at steady-state engine conditions and on a 3 min cycle test. Span gases of unknown concentration were also analyzed. The participants results varied but averaged less than ±5% standard deviation both within (repeatability) and among (reproducibility) the instruments. The short cycle test was in good agreement with the steady-state measurements. No significant difference in the use of Drierite, nonindicating Drierite, or Aquasorb desiccants was evident in sampling system tests.

A cooperative test program was conducted by the CRC-APRAC CAPI-1-64 Composition of Diesel Exhaust Program Group to evaluate the technical aspects of a proposed EPA recommended Heavy Duty Diesel Emission Measurement and Test Procedure. The proposed changes affected the sampling configurations and the types of instruments used. Six participants studied the effects of a number of variables on the proposed changes and evaluated some alternative systems that included both CHEMI and NDIR instruments. The tests were conducted at one site using a multi-cylinder engine operating on the 13-Mode Cycle. Equivalency of systems was demonstrated and the best performance was obtained with a special NDIR system.

The Perm State Microoxidation Test has been used previously to rate the thermal and oxidative stabilities of III C and III D automotive engine sequence reference oils. These ratings show good correlation with the results in the actual engine tests. In this paper, the oxidative and thermal stabilities of a series of heavy duty diesel engine oils are compared with III C and III D reference oils in the PSU microoxidation test using deposit level and overall production of high molecular weight condensation polymers (sludge precursors). These data show the heavy duty diesel engine oils to be more stable than typical III C and III D reference oils. The ratings of the heavy duty diesel engine oils in the PSU microoxidation test based on high molecular weight condensation polymer (sludge precursor) or deposit show excellent correlation with the ratings of the same oils in a 250 hour test in a heavy duty diesel engine.

There is projected to be an increasing demand for the middle distillate (350-640°F) boiling range portion of the crude oil barrel. This is due to increased vehicle dieselization and increased demand for kerosine type jet fuel. To improve jet fuel supply, specifications have been relaxed permitting the use of diesel fuel boiling range material. Since no similar change has been made in diesel fuel specifications, its potential availability is reduced. Increases in the 90% recovery temperature to 680°F to improve diesel fuel supply in Europe have already been made. Similar changes should be made in the U.S. A review of the performance of fuels indicates that there should be no substantial adverse effects when these higher boiling fuels are used. This change could provide as much as 4-1/2% (on crude) more distillate.

A cooperative research program has been completed evaluating the relative impact of fuel composition and engine design features on the emissions and fuel economy of a Toyota light-duty diesel truck. The fuel set was blended from commercially available refinery stocks and consisted of eight fuels with independently varying 10% and 90% distillation temperatures and aromatic content. The engine design variables included two compression ratios and three injector types with different fuel flow characteristics, and three injection timings. The main fuel effects observed were increasing hydrocarbon and particulate emissions with increasing aromatic content and, to a much lesser degree, increasing emissions with increasing 10% and 90% point. Changing from the standard fuel injectors to the reference injectors, which had both a higher nozzle opening pressure and a higher initial fuel flow rate, resulted in a substantial reduction in all emissions and improvements in fuel economy.

This paper presents an approach to modeling the United States truck and bus population. A detailed model is developed that utilizes domestic factory sales figures combined with a scrappage factor as a building block for the total population. Comparison with historical data for 1958-1970 shows that the model follows trends well for intermediate parameters such as total vehicle miles per year, total fuel consumption, scrappage, etc. Fuel consumption and HC, CO, NO2, CO2 and particulate matter emissions for gasoline and diesel engines are of primary interest. The model details these parameters for the time span 1958-2000 in one-year increments. For HC and CO, truck and bus emissions could equal or exceed automobile emissions in the early 1980s, depending on the degree of control. Three population control strategies are analyzed to determine their effects on reducing fuel consumption or air pollution in later years.

Diesel engine exhaust emission characteristics vary considerably with the overall design of the combustion and fuel injection systems. Emission measurements were made on total hydrocarbons, nitrogen oxides, carbon monoxide, carbon dioxide, and smoke. The hydrocarbon measurements of the precombustion chamber engine are considerably lower than the direct injection engine. Less than five pounds of total hydrocarbons per 1000 gal of fuel are produced at rated conditions by all precombustion chamber engines studied. Precombustion chamber engines produce smaller quantities of the oxides of nitrogen when compared to direct injection engines. All diesels produced low carbon monoxide emissions. A novel technique for qualitative and quantitative evaluation of diesel exhaust odors is introduced. Exhaust odor intensity from the precombustion chamber engine is much less than that from the direct injection engine.

A cooperative research program has been completed evaluating the impact of fuel composition (volatility, aromatics and sulfur) on the combustion and emissions performance of a Caterpillar 3406B turbo-charged diesel engine, which is representative of diesel truck engines of the late 1980s. Tests included both steady-state and transient operation measuring regulated and unregulated emissions. The fuel set was blended using only commercially available refinery stocks typical of those which could be considered for use in distillate fuel. The compositions of the blends were selected so that direct measurements of the individual effects of 10% and 90% distillation temperatures, aromatic content, and sulfur content could be made independently. Engine combustion performance data indicated that all fuels operated satisfactorily; aromatic content was as high as 50% and cetane number as low as 39. Further, the cetane number did not predict the engine measured ignition delay in this program.

Studies have been carried out to determine the extent of damage to petroleum and synthetic lubricants resulting from the exposure to various types of nuclear radiation. Means to reduce this damage have also been studied. Three types of exposures have been used, namely, high energy electrons from a Van de Graaff Accelerator, gamma photons from Cobalt 60 and mixed neutrons and gamma particles from a nuclear reactor. Results indicate that radiation damage to lubricating oil base stocks and finished products involves viscosity change, loss of oxidation stability and development of corrosive tendencies. To evaluate lubricants for nuclear reactor systems, preliminary work indicates that static radiation is a useful technique. However, on an equal energy absorbed basis, there appear to be some differences in product damage caused by electrons and gamma rays and indirectly by neutrons.

Paraffinic resins derived from Pennsylvania crude oil are evaluated as viscous lubricants and as blending materials with mineral oils in the preparation of hydraulic fluids and lubricants. The oxidative, thermal, and shear stabilities of the resins and of blends of the resins in mineral oil base stocks have been studied in various rigorous tests from the stand-point of service applications. While the resins provide thickening, the low temperature characteristics of blends show improvement over those prepared with synthetic polymeric additives in that viscosities can be closely approximated on an ASTM viscosity-temperature chart and are unaffected by shearing stresses.

Development and efficient utilization of our natural energy resources are receiving national attention. One major user of energy is the transportation industry. In 1975, the United States Government enacted the Energy Policy and Conservation Act which has a section aimed at improving automobile efficiency. One approach being considered to reduce passenger car energy demand is the use of diesel engines instead of gasoline engines. This paper presents the results of a study exploring the potential passenger car demand for diesel fuel and the implication of this demand on the petroleum industry processing requirements. In addition, an evaluation of the relative economy, performance and emissions of diesel-powered cars versus gasoline-powered cars is presented. An estimate of the net energy utilization in terms of both miles traveled per barrel of crude and crude savings for various degrees of diesel engine penetration in the automobile market is given.

Chromatographic analysis of diesel exhaust indicates a number of low molecular weight hydrocarbons, below C6. Using reactivity index as a criterion, much of the diesel exhaust reactivity can be attributed to ethylene and propylene caused by the thermal decomposition of the fuel. Hydrocarbons in the C4-C7 range, including high relative reactivity olefins, are generally low in volume concentration and therefore contribute little to the overall exhaust reactivity. Hydrocarbons, in terms of parts per million carbon above C7 are low in present diesel engine designs, so individual volume concentrations are generally fractional parts per million. Reactivity per horsepower-hour from diesel engine exhaust is less than that from the one small industrial gasoline engine tested by the heavy-duty truck diesel engine cycle.

One of the more objectionable aspects of the use of the diesel engine is its emission of particulate matter. Methods for collecting particulate matter samples in the undiluted exhaust gases with an Andersen Impactor for gravimetric and electron microscopy analysis are developed. A direct injection Vee-eight naturally aspirated diesel engine was used in the study. This paper presents the results of an in-depth study of the physical characteristics of diesel particles. The size distribution of the particulate matter was obtained using an Andersen Inertial Impactor for the engine conditions applicable to the SAE 13-mode cycle. The particulate matter was analyzed using both scanning and transmission electron microscopes and was found to be comprised of individual spherical particles ranging from 100 ņ to 800 Å with a mean size of approximately 260 Å. The particulate matter was analyzed for carbon, hydrogen and nitrogen.

The techniques used to characterize the chemical and physical nature of particulates in diesel exhaust emissions are reviewed. The emphasis is on understanding the broader aspects of the fundamental nature of not only diesel particulates, but particulate systems in general. Consideration is given to the special nature of particulates which make them significant pollutants and to the relative place of the diesel in the formation of man-made particles. The underlying combustion processes leading to carbon and sulfur based particulates are reviewed. The important variables in steps of the combustion processes which lead to particulate formation are considered, as well as major fuel and engine factors. Collection methods are examined with examples given from current diesel dilution techniques. Probes, sampling lines, and instrumentation are considered.