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Dimethyl ether (DME) is an alternative to diesel fuel for use in compression-ignition engines with modified fuel systems and offers potential advantages of efficiency improvements and emission reductions. DME can be produced from natural gas (NG) or from renewable feedstocks such as landfill gas (LFG) or renewable natural gas from manure waste streams (MANR) or any other biomass. This study investigates the well-to-wheels (WTW) energy use and emissions of five DME production pathways as compared with those of petroleum gasoline and diesel using the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET®) model developed at Argonne National Laboratory (ANL).

This paper reports our efforts to develop an instrument, TG-1, to measure particulate emissions from diesel engines in real-time. TG-1 while based on laser-induced incandescence allows measurements at 10 Hz on typical engine exhausts. Using such an instrument, measurements were performed in the exhaust of a 1.7L Mercedes Benz engine coupled to a low-inertia dynamometer. Comparative measurements performed under engine steady state conditions showed the instrument to agree within ±12% of measurements performed with an SMPS. Moreover, the instrument had far better time response and time resolution than a TEOM® 1105. Also, TG-1 appears to surpass the shortcomings of the TEOM instrument, i.e., of yielding negative values under certain engine conditions and, being sensitive to external vibration.

An increase in spark-ignition engine efficiency can be gained by increasing the engine compression ratio, which requires fuels with higher knock resistance. Oxygenated fuel components, such as methanol, ethanol, isopropanol, or iso-butanol, all have a Research Octane Number (RON) higher than 100. The octane numbers (ON) of fuels are rated on the CFR F1/F2 engine by comparing the knock intensity of a sample fuel relative to that of bracketing primary reference fuels (PRF). The PRFs are a binary blend of iso-octane, which is defined to an ON of 100, and n-heptane, which represents an ON of 0. Above 100 ON, the PRF scale continues by adding diluted tetraethyl lead (TEL) to iso-octane. However, TEL is banned from use in commercial gasoline because of its toxicity. The ASTM octane number test methods have a “Fit for Use” test that validate the CFR engine’s compliance with the octane testing method by verifying the defined ON of toluene standardization fuels (TSF).

Recent advances in fuel-cell technology and low-emission, direct-injection spark-ignition and diesel engines for vehicles could significantly change the transportation vehicle power plant landscape in the next decade or so. This paper is a scoping study that compares total fuel cycle options for providing power to personal transport vehicles. The key question asked is, “How much of the energy from the fuel feedstock is available for motive power?” Emissions of selected criteria pollutants and greenhouse gases are qualitatively discussed. This analysis illustrates the differences among options; it is not intended to be exhaustive. Cases considered are hydrogen fuel from methane and from iso-octane in generic proton-exchange membrane (PEM) fuel-cell vehicles, methane and iso-octane in spark-ignition (SI) engine vehicles, and diesel fuel (from methane or petroleum) in direct-injection (DI) diesel engine vehicles.

Ethanol has received both positive and negative attention as a renewable fuel for spark ignition engines. Studies of ethanol have shown improved volumetric efficiency, knock tolerance, and favorable burn curves[1]. Nevertheless, little research has been published exploring the impact of ethanol blends on race engine performance coupled with the impact on well-to-wheels (WTW) greenhouse gases, emissions, and petroleum reduction. In this work, a circle track race vehicle powered by a GM Performance Parts 6.2L OHV CT-525 engine was tested using 100 octane race fuel and E85 over a matrix of configurations. Carburetion vs. fuel injection configurations were benchmarked with both fuels, with the addition of 100- and 300-cells-per-inch catalytic convertors. Testing involved both dynamometer testing and on-track testing utilizing a portable emissions measurement system.

Hydrogen is considered one of the most promising future energy carriers and transportation fuels. Because of the lack of a hydrogen infrastructure and refueling stations, widespread introduction of vehicles powered by pure hydrogen is not likely in the near future. Blending hydrogen with methane could be one solution. Such blends take advantage of the unique combustion properties of hydrogen and, at the same time, reduce the demand for pure hydrogen. In this paper, the authors analyze the combustion properties of hydrogen/methane blends (5% and 20% methane [by volume] in hydrogen equal to 30% and 65% methane [by mass] in hydrogen) and compare them to those of pure hydrogen as a reference. The study confirms that only minor adjustments in spark timing and injection duration are necessary for an engine calibrated and tuned for operation on pure hydrogen to run on hydrogen/methane blends.

Recovering metals from obsolete automobiles, home appliances, and other metal-containing obsolete durables and other scrap involves shredding these objects and separating the reusable metals from the shredded material by using magnets, eddy current separators, and metal detectors. Over 12 million automobiles are shredded annually in the United States alone, and almost all of the 4.5 million metric tonnes (5 million short tons) of the shredder residue produced in the United States annually is disposed of in landfills. Over 13.6 million tonnes (15 million tons) of shredder residue is generated worldwide every year. The rise in disposal costs is further exacerbated in that the percentage of shredder residue that must be disposed of, in comparison with the percentage of marketable recovered metals, is increasing because of the increasing content of polymers in automobiles and in home appliances.

Alternative fuels for internal combustion engines have been the subject of numerous studies. The new U.S. Renewable Fuel Standard has made it a requirement to increase the production of ethanol and advanced biofuels to 36 billion gallons by 2022. Because corn-based ethanol will be capped at 15 billion gallons, 21 billion gallons must come from the advanced biofuels category. A potential source to fill the gap may be butanol and its isomers as they possess fuel properties superior to ethanol. Recently, concerns have been raised about emission of currently non-regulated constituents, aldehydes in particular, from alcohol-based fuels. In an effort to assess the relative impact of the U.S. Renewable Fuel Standards on emissions from a modern gasoline engine, both regulated and non-regulated gas constituents were measured from the combustion of three different alcohol isomers in a modern direct-injected (DI) spark ignition (SI) gasoline engine.

Currently there is a significant research effort being made in gasoline spark/ignition (SI) engines to understand and reduce cycle-to-cycle variations. One of the phenomena that presents this cycle-to-cycle variation is combustion knock, which also happens to have a very stochastic behavior in modern SI engines. Conversely, the CFR octane rating engine presents much more repeatable combustion knock activity. The aim of this study is to assess the impact of fuel composition on the cycle to cycle variation of the pressure and timing of end gas autoignition. The variation of cylinder conditions at the timing of end-gas autoignition (knock point) for a wide selection of cycle ensembles have been analyzed for several constant RON 98 fuels on the CFR engine, as well as in a modern single-cylinder gasoline direct injection (GDI) SI engine operated at RON-like intake conditions.

Numerical simulations of soot formation were performed for n-dodecane spray using the transported probability density function (TPDF) method. Liquid n-dodecane was injected with 1500 bar fuel pressure into a constant-volume vessel with an ambient temperature, oxygen volume fraction and density of 900 K, 15% and 22.8 kg/m3, respectively. The interaction by exchange with the mean (IEM) model was employed to close the micro-mixing term. The unsteady Reynolds-averaged Navier-Stokes (RANS) equations coupled with the realizable k-ε turbulence model were used to provide turbulence information to the TPDF solver. A 53-species reduced n-dodecane chemical mechanism was employed to evaluate the reaction rates. Soot formation was modelled with an acetylene-based two-equation model which accounts for simultaneous soot particle inception, surface growth, coagulation and oxidation by O2 and OH.

Disposal of automobile shredder residue (ASR), remaining from the reclamation of steel from junked automobiles, promises to be an increasing environmental and economic concern. Argonne National Laboratory (ANL) is investigating alternative technology for recovering value from ASR while also, it is hoped, lessening landfill disposal concerns. Of the ASR total, some 20% by weight consists of plastics. Preliminary work at ANL is being directed toward developing a protocol, both mechanical and chemical (solvent dissolution), to separate and recover polyurethane foam and the major thermoplastic fraction from ASR. Feasibility has been demonstrated in laboratory-size equipment.

This paper presents the results of efficiency, emissions, and performance testing of a supercharged, hydrogen-powered, four-cylinder engine. Tests were run at various speeds, loads, and air/fuel ratios in order to identify advantageous operating regimes. The tests revealed that a maximum thermal brake efficiency of 37% could be achieved and that certain operating regimes could achieve NOx emissions as low as 1 ppm without aftertreatment. Measurement of cylinder pressure traces in all four cylinders allowed a detailed assessment of cylinder-cylinder deviation. Several measures to further increase hydrogen engine performance in order to reach the goals set by the U.S. Department of Energy are being discussed.

This paper reports an effort to measure particulate emissions from a modern light duty CIDI engine equipped with a common-rail fuel injection system, a closed loop EGR system and a state-of-the-art aftertreatment system. Particulate emissions both upstream and downstream of the catalyst were measured using an SMPS system and a TEOM while operating the engine at various steady-state conditions. The measurements upstream of the catalyst show that the particulate emissions are strongly dependent on the engine speed, load and EGR conditions. The measurements downstream of the catalyst show the effectiveness of the catalyst in reducing particulate mass emissions by 20-80%, with reductions in particulate mean diameters averaging about 10%. The trends observed are discussed in terms of previously established particulate formation and destruction mechanisms.

Many concepts of premixed diesel combustion at reduced temperatures have been investigated over the last decade as a means to simultaneously decrease engine-out particle and oxide of nitrogen (NO ) emissions. To overcome the trade-off between simultaneously low particle and NO emissions versus high "diesel-like" combustion efficiency, a new dual-fuel technique called Reactivity Controlled Compression Ignition (RCCI) has been researched. In the present study, particle size distributions were measured from RCCI for four gasoline:diesel compositions from 65%:35% to 84%:16%, respectively. Previously, fuel blending (reactivity control) had been carried out by a port fuel injection of the higher volatility fuel and a direct in-cylinder injection of the lower volatility fuel. With a recent mechanical upgrade, it was possible to perform injections of both fuels directly into the combustion chamber.

The limited spatial area in conventional diesel particulate filter (DPF) systems requires frequent regenerations to remove collected particulate matter (PM) emissions, consequently resulting in higher energy consumption and potential material failure. Due to the complex geometry and difficulty in access to the internal structure of diesel particulate filters, in addition, many important characteristics in filtration processes remain unknown. In this work, therefore, the geometry of DPF membrane channels was modified basically to increase the filtration areas, and their filtration characteristics were evaluated in terms of pressure drop across the DPF membranes, effects of soot loading on pressure drop, and qualitative soot mass distribution in the membrane channels. In this evaluation, an analytical model was developed for pressure drop, which allowed a parametric study with those modified membranes.

Gasoline compression ignition (GCI) using a single gasoline-type fuel for direct/port injection has been shown as a method to achieve low-temperature combustion with low engine-out NOx and soot emissions and high indicated thermal efficiency. However, key technical barriers to achieving low temperature combustion on multi-cylinder engines include the air handling system (limited amount of exhaust gas recirculation (EGR)) as well as mechanical engine limitations (e.g. peak pressure rise rate). In light of these limitations, high temperature combustion with reduced amounts of EGR appears more practical. Previous studies with 93 AKI gasoline demonstrated that the port and direct injection strategy exhibited the best performance, but the premature combustion event prevented further increase in the premixed gasoline fraction and efficiency.

This paper performs a parametric analysis of the influence of numerical grid resolution and turbulence model on jet penetration and mixture formation in a DI-H2 ICE. The cylinder geometry is typical of passenger-car sized spark-ignited engines, with a centrally located single-hole injector nozzle. The simulation includes the intake and exhaust port geometry, in order to account for the actual flow field within the cylinder when injection of hydrogen starts. A reduced geometry is then used to focus on the mixture formation process. The numerically predicted hydrogen mole-fraction fields are compared to experimental data from quantitative laser-based imaging in a corresponding optically accessible engine. In general, the results show that with proper mesh and turbulence settings, remarkable agreement between numerical and experimental data in terms of fuel jet evolution and mixture formation can be achieved.

It is beneficial but challenging to operate spark-ignition engines under highly lean and dilute conditions. The unstable ignition behavior can result in downgraded combustion performance in engine cylinders. Numerical approach is serving as a promising tool to identify the ignition requirements by providing insight into the complex physical/chemical phenomena. An effort to simulate the early stage of flame kernel initiation in lean and dilute fuel/air mixture has been made and discussed in this paper. The simulations are set to validate against laboratory results of spark ignition behavior in a constant volume combustion vessel. In order to present a practical as well as comprehensive ignition model, the simulations are performed by taking into consideration the discharge circuit analysis, the detailed reaction mechanism, and local heat transfer between the flame kernel and spark plug.

While sulfur in diesel fuels helps reduce friction and prevents wear and galling in fuel pump and injector systems, it also creates environmental pollution in the form of hazardous particulates and SO2 emissions. The environmental concern is the driving force behind industry's efforts to come up with new alternative approaches to this problem. One such approach is to replace sulfur in diesel fuels with other chemicals that would maintain the antifriction and antiwear properties provided by sulfur in diesel fuels while at the same time reducing particulate emissions. A second alternative might be to surface-treat fuel injection parts (i.e., nitriding, carburizing, or coating the surfaces) to reduce or eliminate failures associated with the use of low-sulfur diesel fuels. Our research explores the potential usefulness of a near-frictionless carbon (NFC) film developed at Argonne National Laboratory in alleviating the aforementioned problems.

Applying nanotechnology to thermal engineering, ANL has addressed the interesting and timely topic of nanofluids. We have developed methods for producing both oxide and metal nanofluids, studied their thermal conductivity, and obtained promising results: (1) Stable suspensions of nanoparticles can be achieved. (2) Nanofluids have significantly higher thermal conductivities than their base liquids. (3) Measured thermal conductivities of nanofluids are much greater than predicted. For these reasons, nanofluids show promise for improving the design and performance of vehicle thermal management systems. However, critical barriers to further development and application of nanofluid technology are agglomeration of nanoparticles and oxidation of metallic nanoparticles. Therefore, methods to prevent particle agglomeration and degradation are required.