Browse Topic: Biofuels

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Test Publishing DocumentARP090824B (Current)10/13/2025
Test Publishing Document6667
A-6 Aerospace Actuation, Control and Fluid Power Systems
Ducted Fuel Injection Provides Consistently Lower Soot Emissions in Sweep to Full-Load Conditions03-19-01-00017/14/2023
Abstract Earlier studies have proven how ducted fuel injection (DFI) substantially reduces soot for low- and mid-load conditions in heavy-duty engines, without significant adverse effects on other emissions. Nevertheless, no comprehensive DFI study exists showing soot reductions at high- and full-load conditions. This study investigated DFI in a single-cylinder, 1.7-L, optical engine from low- to full-load conditions with a low-net-carbon fuel consisting of 80% renewable diesel and 20% biodiesel. Over the tested load range, DFI reduced engine-out soot by 38.1–63.1% compared to conventional diesel combustion (CDC). This soot reduction occurred without significant detrimental effects on other emission types. Thus, DFI reduced the severity of the soot–NOx tradeoff at all tested conditions. While DFI delivered considerable soot reductions in the present study, previous DFI studies at low- and mid-load conditions delivered larger soot reductions (>90%) compared to CDC operation at the same conditions. Therefore, the DFI configuration used here has been deemed nonoptimal (in terms of parameters such as the injector-spray and piston geometries), and several improvements are recommended for future studies with high-load DFI. These improvements include employing better spray-duct alignment, a deeper piston bowl with a smaller injector umbrella angle, and a fuel injector that opens and closes faster. The study also suggests future research to make DFI ready for commercialization, such as metal-engine tests to ensure desirable DFI performance over an engine’s complete speed/load map. Overall, this study supports the continued development and commercialization of DFI to meet upcoming emissions regulations for heavy-duty vehicles. Specifically, multicylinder engine experiments and CFD simulations should be utilized to optimize the performance and clarify the full potential of DFI.
Buurman, Noad J., Nyrenstedt, Gustav, Mueller, Charles J.
Assembly and Soldering Criteria for High Quality/High Reliability Soldering Wire and Cable Termination in Aerospace VehiclesAS4461D (Current)7/23/2021
This standard is applicable to manual soldering and machine soldering processes utilizing controlled soldering devices, for electrical connections for wiring and cabling used in aerospace vehicles. Description of a component or device herein is not to be construed as authorizing the use of the component or device.
AE-8A Elec Wiring and Fiber Optic Interconnect Sys Install
Oxygen System and Component CleaningARP1176B (Current)10/19/2020
This SAE Aerospace Recommended Practice (ARP) provides recommended practices for the cleaning of aircraft oxygen equipment, both metallic and non-metallic articles, such as oxygen lines (tubes, hoses, etc.), components (including regulator and valve parts), cylinders, and ground-based equipment that may be used to support aircraft oxygen systems. This document also specifies work area details, methods for selecting suitable cleaning agents, cleaning methods, and test methods for verifying levels of cleanliness. The cleanliness coding scheme specified in this document provides a method for documenting minimum cleanliness level requirements and for identifying compliance.
A-10 Aircraft Oxygen Equipment Committee
Dragonfly : Defining Environments for Rotorcraft Flight on TitanF-0076-2020-1630110/5/2020
Dragonfly is an X-8 octocopter designed to explore Saturn's moon Titan, and is currently under development for launch in 2026. Titan is a uniquely favorable body for atmospheric flight, in that it has a low gravity (1/7 Earth's) and a dense atmosphere (4x Earth's) which reduce the energetic requirements for heavier-than-air flight. Dragonfly will make multiple (autonomous) flights over several years with ranges of the order of 10km to explore different sites on Titan. The key features of the Titan environment are reviewed. These include the characteristics of the landing site terrain, resembling dune fields in terrestrial deserts. Winds are generally very low, ∼ 1m/s. Stronger winds, and methane rainfall, can occur in rare rainstorms, but these are not expected at the latitude and season of Dragonfly's arrival. Brownout and triboelectric charging due to surface dust lofted by rotor downwash is possible, and these hazards and their mitigations are discussed.
Lorenz, Ralph
Breathalyzer Detects MarijuanaTBMG-359712/1/2020
As recreational marijuana legalization becomes more widespread in the U.S., so has concern about what that means for enforcing driving-under-the-influence (DUI) laws. Unlike a breathalyzer used to detect alcohol, police do not have a device that can be used in the field to determine if a driver is under the influence of marijuana.
In-Situ Resource Utilization (ISRU): Methylotrophic Microorganisms Expressing Soluble Methane Monooxygenase ProteinsTBMG-358121/1/2020
Long-duration missions to planetary bodies and deep space will require new technological developments that support human habitation in transit and on distant bodies. Microorganisms are unique from the standpoint that they can be employed as self-replicating bio-factories to produce both native and engineered mission-relevant bio-products. Methane (CH4) usage in In-Space Manufacturing (ISM) platforms has been discussed previously for human exploration and has been proposed to be used in physicochemical systems as a propulsion fuel, supply gas, and in fuel cells.
A Study of a Lean Homogeneous Combustion Engine System with a Fuel Reformer Cylinder2019-01-217712/19/2019
The Dual-Fuel (DF) combustion is a promising technology for efficient, low NOx and low exhaust particulate matter (PM) engine operation. To achieve equivalent performance to a DF engine with only the use of conventional liquid fuel, this study proposes the implementation of an on-board fuel reformation process by piston compression. For concept verification, DF combustion tests with representative reformed gas components were conducted. Based on the results, the controllability of the reformed gas composition by variations in the operating conditions of the reformer cylinder were discussed.
Asai, Go, Tokuoka, Yuki, Bayer, Thomas, Ishiguro, Shuntaro, Shibata, Gen, Ogawa, Hideyuki, Kobashi, Yoshimitsu, Watanabe, Yusuke
Oxidation of Soybean Biodiesel Fuel in Diesel Engine Oils04-12-03-001512/5/2019
Abstract During diesel engine operation, some fuel is entrained in engine oil, particularly as a consequence of strategies to regenerate NOx traps or particle filters. This “fuel dilution” of oil can adversely affect engine oil properties and performance. Compared to diesel fuel, biodiesel is more prone to fuel dilution and more susceptible to oxidation. Oxidation stability experiments were conducted at 160°C using a modified Rapid Small-Scale Oxidation Test (RSSOT) and a Rancimat instrument with 0, 5, 10, and 20 wt% biodiesel in four fully formulated engine oils, two partially formulated engine oils, and two base oils. These experiments showed decreasing oxidation stability with increasing biodiesel content. An exception was noted with the least stable oils (two base oils and one engine oil) in which 5 wt% biodiesel improved the oxidation stability relative to oil without biodiesel. Experiments with biodiesel distillation fractions identified this stability enhancement within the least volatile biodiesel fraction, consistent with natural antioxidants in the biodiesel. Omission of two engine oil additives, antioxidants and zinc dialkyldithiophosphates (ZDDP), led to an unexpected increase in oxidation stability (with and without biodiesel). Time-series oxidation experiments at 160°C with one of the fully formulated engine oils, with and without 20 wt% biodiesel, demonstrated that the biodiesel caused greater oxidation instability and extent of oxidation, greater formation of peroxides and reduction in total base number (TBN), increased ester content, and higher density. Kinematic viscosity increased with aging time and eventually surpassed that of the engine oil aged without biodiesel. With extended aging time, the fully formulated engine oil containing biodiesel “broke,” forming black tar-like materials with high viscosity.
Ball, James C., Anderson, James E., Duckworth, Jacob A., Uy, Dairene, Wallington, Timothy J.
New Silk Materials Can Wrinkle into Detailed Patterns, Then Unwrinkle to Be “Reprinted”TBMG-3562012/1/2019
Researchers at Tufts University School of Engineering have developed silk materials that can wrinkle into highly detailed patterns — including words, textures, and images as intricate as a QR code or a fingerprint. The patterns take about one second to form, are stable, but can be erased by flooding the surface of the silk with vapor, allowing the researchers to “reverse” the printing and start again. In an article published in the Proceedings of the National Academy of Sciences, the researchers demonstrate examples of the silk wrinkle patterns, and envision a wide range of potential applications for optical electronic devices.1
A Mathematical Expression to Predict the Influence of Ethanol Concentration on Distillation Behavior of Gasoline-Ethanol Fuel Blend and Impact of Non-Ionic Surfactant on E20 Fuel2019-28-238611/21/2019
Blending of primary alcohol in gasoline surges the vapour pressure significantly and exhibits azeotrope behaviour that effect severely on the atmospheric distillation yields. In this experiment, primary alcohol (Ethanol) were blended in varied volumetric proportion (5%, 10%, 15%, 20%, 25%) with hydrocracked gasoline, influence on volatility behaviour and distillation properties were investigated. Physical properties of this blends were investigated for vapour pressure (VP), VLI, DI and distillation which were selected to evaluate the influence of alcohol in azeotrope behaviour of the fuel mix reflected through pattern of distillation curve (temperature vs % recovery range). This fuel mix exhibited rise in recovery at 700C (E70), VP, VLI and area of azeotrope with increase in % of alcohol volume in gasoline blend. A linear equation is established from the distillation data to predict the impact of % ethanol on % volume recovery and maximum temperature drop in distillation test of gasoline-ethanol fuel blends. Addition of non-ionic surfactant in ethanol blended gasoline (E20) reduces the azeotrope behaviour significantly and flattens the distillation curve. E70, vapour lock index (VLI), driveability index (DI) and area of azeotrope reduces proportionately with the increment of surfactant dosage (%) in E20. This provides a useful information for designing a suitable ethanol blended gasoline fuel, dedicated to spark ignition engine for all weather conditions.
Mitra, Siddhartha, Adimoolam, Rajendiran, Sutar, Kashinath, Ganguli, Debashis
Influence of Addition of Ethanol into Non-Edible Biodiesel from Rice Bran Oil on the Properties and Performance - An Experimental Study in Direct Injection VCR Diesel Engine2019-28-016010/11/2019
Non-edible oil biodiesels and alcohols are the two major liquid fuel sources available to replace diesel to fuel compression ignition engine. This study is to investigate the solubility, properties and performance of biodiesel from non-edible rice bran oil and ethanol. Solubility test was conducted in three different temperatures 50C, 150C& room temperature (300C approximately). The stable blends were tested for essential properties such as energy content, cetane number, kinematic viscosity, heat of vaporisation, flash point and oxygen content as per ASTM standards. Biodiesel- ethanol blends containing 30% of ethanol was found stable up to 50C. This blend also met the minimum requirement with respect to properties to fuel compression ignition engine. These blends were tested in compression ignition engine for performance, combustion and emission characteristics in various load conditions under two compression ratios (17,1 & 18,1). Results showed that the compression ratio 18:1 was found suitable for the optimal blend. This blend produced brake thermal efficiency, peak incylinder pressure, peak heat release rate, hydrocarbon, carbon monoxide, and smoke similar to that of diesel. However, ignition delay & emission of oxides of nitrogen produced by this blend was found slightly higher compared to diesel.
Balasubramanian, Prabakaran, Shanmuga Sundaram, Padmanaba Sundar, Manoharan, Hemakumar
Methane Detector Sniffs Out LeaksTBMG-351569/1/2019
Methane is everywhere on Earth. It’s the main ingredient in the natural gas that powers heating, cooking, and electricity. It’s also a potent greenhouse gas. The presence of methane is also interesting for a different reason: because the biggest source of the gas on Earth is bacterial life. That means when NASA planetary scientists caught a glimpse of it on Mars, it merited a closer look.
Mobile, Dual-Comb Device for Methane Leak DetectionTBMG-351459/1/2019
Accurately detecting, locating, and quantifying leaks of methane — the main component of natural gas and a major fuel source worldwide — is critically important for both environmental and economic reasons. Unfortunately, traditional methods are slow, labor-intensive, limited to small coverage areas, and expensive to operate over time.
Process Directly Converts Methane to MethanolTBMG-349348/1/2019
Methanol is a key feedstock for the production of chemicals, some of which are used to make products such as plastics, plywood, and paints. Methanol also can fuel vehicles or be reformed to produce high-grade hydrogen for fuel cells. The current method for producing methanol from methane- or coal-derived synthesis gas involves a multi-step process that is neither efficient nor economical in small-scale applications. As a result, methane emissions from oil wells — accounting for 210 billion cubic feet of natural gas annually — are being vented and flared, according to the U.S. Energy Information Administration.
Etching of Fluoropolymer InsulationsARP6167 (Current)6/11/2019
This SAE Aerospace Recommended Practice (ARP) describes the etching of fluoropolymer electrical wire insulations to ensure that all facets of the process from the chemistry to the processing, to the storage and handling are well defined.
AE-8A Elec Wiring and Fiber Optic Interconnect Sys Install
Testing of Elastomer Icephobic Coatings in the AIWT: Lessons Learned2019-01-19946/10/2019
A study has been conducted into icephobic properties of some highly durable “off-the-shelf” elastomer materials using a rotating ice adhesion test rig installed in the NRC’s Altitude Icing Wind Tunnel. This enabled the formation of ice at environmental conditions similar to those experienced during in-flight icing encounters. Initially, the tests indicated some very positive results with ice adhesion shear stress as low as 8KPa. On further examination, however, it became apparent that the test preparation process, in which the samples were cleaned with an ethanol alcohol solution, influenced the results due to absorption and prolonged retention of the cleaning fluid. The uptake of the ethanol alcohol solution by the elastomer was found to be a function of the surface temperature and remained absorbed into the coating during the ice accretion process changing the characteristics of the coating in such a way that led to a reduction in the ice/surface bond strength.
Orchard, David, Chevrette, Gislain, Maillard, Damien, Khoun, Lolei
Stretchable Interlaced-Nanowire Film for Ultraviolet Photodetectors with High Response SpeedTBMG-345886/1/2019
Stretchable electronics, which can be stretched, deformed and wrapped onto nonplanar curved surfaces, have attracted much attraction due to their potential applications in wearable electronics, implantable biomedical devices, and artificial electronic skin. So far, many types of stretchable electronic devices have been developed including stretchable transistors, light-emitting diodes (LEDs), supercapacitors, photodetectors and sensors. Ultraviolet (UV) photodetectors have wide applications in crime investigation, biological analysis, fire monitoring, UV irradiation detection and many other applications as well.
A Computational Study on Laminar Flame Propagation in Mixtures with Non-Zero Reaction Progress2019-01-09464/2/2019
Flame speed data reported in most literature are acquired in conventional apparatus such as the spherical combustion bomb and counterflow burner, and are limited to atmospheric pressure and ambient or slightly elevated unburnt temperatures. As such, these data bear little relevance to internal combustion engines and gas turbines, which operate under typical pressures of 10-50 bar and unburnt temperature up to 900K or higher. These elevated temperatures and pressures not only modify dominant flame chemistry, but more importantly, they inevitably facilitate pre-ignition reactions and hence can change the upstream thermodynamic and chemical conditions of a regular hot flame leading to modified flame properties. This study focuses on how auto-ignition chemistry affects flame propagation, especially in the negative-temperature coefficient (NTC) regime, where dimethyl ether (DME), n-heptane and iso-octane are chosen for study as typical fuels exhibiting low temperature chemistry (LTC). The computation of laminar flame speed of lean and stoichiometric mixtures of fuel/air was performed at different ignition reaction progress, by selecting the thermal chemical states corresponding to different residence times during auto-ignition as the flame upstream condition. Using scaling and budget analysis, it is shown that a well-defined flame speed for such a partially reactive mixture in the classical diffusion-reaction limit could still be feasible in the appropriate computational domain, especially with a sufficiently reduced induction length. The comparison of flame speed against different types of progress variables indicates a nearly linear relationship between the flame speed and progress variables based on the fuel mass fraction and temperature. Thermal and chemical effect of a cool-flame upstream has been isolated by comparing the flame speed of the initial mixture and that of the instantaneous mixture under the same thermodynamic conditions. It is found that the enhanced propagation is shown to be largely a thermodynamic effect, while chemistry nevertheless plays an overall retarding role. Sensitivity analysis has been performed to identify the key species which most influence flame propagation at different reaction progress. A general scheme of simplified mixture was constructed to describe flame propagation in a partially reactive mixture, for both lean and stoichiometric, as well as high pressures conditions. This study provides useful insights into flame propagation in practical engine conditions.
Lin, Han, Zhao, Peng, Ge, Haiwen
Contaminants Affecting the Formation of Soft Particles in Bio-Based Diesel Fuels during Degradation2019-01-00161/15/2019
Renewable fuels are essential in the field of heavy duty transportation if we are to reach a fossil-free society in the foreseeable future. However renewable diesel fuels based on fatty acid methyl ester (FAME) might face problems with degradation and with cold flow properties. From the perspective of an engine, this may cause problems in the fuel injection system, such as fuel filter clogging and injector deposits. These phenomena, especially fuel filter clogging, can be connected to gel-like soft particles, which could originate from degradation products as well as from byproducts created during biodiesel refining. In this study, soft particles from the degradation of bio-based diesel fuel were examined. The tested fuels included hydrogenated vegetable oils (HVO), rapeseed methyl ester (RME) and 10% blend of rapeseed methyl ester with standard diesel (B10). To test their potential to increase the formation of soft particles, contaminants such as water, metals and engine oil were included in the degradation methods. The formed insoluble products were analyzed with gravimetric means, scanning electron microscopy (SEM/EDX) and spectroscopy methods (FTIR). The results showed different behavior for each of the tested fuels. B10 was shown to be the most problematic, with the creation of gel-like soft particles. RME was less prone to create particles, probably due to its good solubility properties. HVO created the least sediments, possibly due to its high stability. According to the FTIR measurements, the captured insoluble sediments mainly consisted of polymerized oxidation products, acids and metal carboxylic ions. The type of metal influenced the chemical composition and the amount of insoluble sediment. Engine oil caused an increase in the amount of sediments. However the results also suggest that oil has a dampening effect for reactions between metals, water and fuels.
Csontos, Botond, Alim, Richard, Bernemyr, Hanna, Hittig, Henrik, Pach, Mayte
Heat of Vaporization and Species Evolution during Gasoline Evaporation Measured by DSC/TGA/MS for Blends of C1 to C4 Alcohols in Commercial Gasoline Blendstocks2019-01-00141/15/2019
Evaporative cooling of the fuel-air charge by fuel evaporation is an important feature of direct-injection spark-ignition engines that improves fuel knock resistance and reduces pumping losses at intermediate load, but in some cases, may increase fine particle emissions. We have reported on experimental approaches for measuring both total heat of vaporization and examination of the evaporative heat effect as a function of fraction evaporated for gasolines and ethanol blends. In this paper, we extend this work to include other low-molecular-weight alcohols and present results on species evolution during fuel evaporation by coupling a mass spectrometer to our differential scanning calorimetry/thermogravimetric analysis instrument. The alcohols examined were methanol, ethanol, 1-propanol, isopropanol, 2-butanol, and isobutanol at 10 volume percent, 20 volume percent, and 30 volume percent. The results show that total heat of vaporization of the alcohol gasoline blends is in line with the decreasing heat of vaporization in kilojoules per kilogram with increasing alcohol carbon number, as expected. Mass spectrometer results show that methanol fully evaporates at significantly lower fraction evaporated relative to other alcohols even though it is present at higher molar concentration at a fixed volumetric concentration. Certain alcohols, especially methanol and ethanol, can suppress the evaporation of aromatic compounds such as cumene during the evaporation process in some samples. While the use of mass spectrometry to analyze the composition of the evolving gas mixture provided useful results for a relatively simple research gasoline (FACE B), additional research is required to practically apply this methodology to more complex commercial gasolines.
Fioroni, Gina M., Christensen, Earl, Fouts, Lisa, McCormick, Robert
Estimation of the Fuel Efficiency Potential of Six Gasoline Blendstocks Identified by the U.S. Department of Energy’s Co-Optimization of Fuels and Engines Program2019-01-00171/15/2019
Six blendstocks identified by the Co-Optimization of Fuels & Engines Program were used to prepare fuel blends using a fixed blendstock for oxygenate blending and a target RON of 97. The blendstocks included ethanol, n-propanol, isopropanol, isobutanol, diisobutylene, and a bioreformate surrogate. The blends were analyzed and used to establish interaction factors for a non-linear molar blending model that was used to predict RON and MON of volumetric blends of the blendstocks up to 35 vol%. Projections of efficiency increase, volumetric fuel economy increase, and tailpipe CO2 emissions decrease were produced using two different estimation techniques to evaluate the potential benefits of the blendstocks. Ethanol was projected to provide the greatest benefits in efficiency and tailpipe CO2 emissions, but at intermediate levels of volumetric fuel economy increase over a smaller range of blends than other blendstocks. A bioreformate surrogate blendstock was projected to provide the greatest increase in volumetric fuel economy and the lowest increase in efficiency. Tailpipe CO2 emissions for blends of the bioreformate surrogate were higher at all blend levels compared to the baseline E10 fuel.
Sluder, C. Scott
Assessing the Impact of FAME and Diesel Fuel Composition on Stability and Vehicle Filter Blocking2019-01-00491/15/2019
In recent years, there has been an impetus in the automotive industry to develop newer diesel injection systems with a view to reducing fuel consumption and emissions. This development has led to hardware capable of higher pressures, typically up to 2500 bar. An increase in pressure will result in a corresponding increase in fuel temperature after compression with studies showing changes in fuel temperatures of up to 150 °C in 1000-2500 bar injection systems. Until recently, the addition of Fatty Acid Methyl Esters, FAME, to diesel had been blamed for a number of fuel system durability issues such as injector deposits and fuel filter blocking. Despite a growing acceptance within the automotive and petrochemical industries that FAME is not solely to blame for diesel instability, there is a lack of published literature in the area, with many studies still focusing on FAME oxidation to explain deposit formation and hardware durability. The majority of studies into diesel degradation are conducted under non-representative laboratory conditions, or are extrapolated from the deposits found in filters from vehicles with failed injectors. In this study, the cause of this degradation was investigated by using a novel High Pressure Common Rail (HPCR) non-firing rig designed to mimic a diesel common rail system, simulating realistic, albeit accelerated, operating conditions. The degree of deposition on the system fuel filter was monitored, for both petroleum diesel (B0), RF79 (B0), Bx (where x is percentage volume/volume of FAME) and surrogate diesel fuel components. A systematic study of synthetic surrogates demonstrated that, as well as FAME, any base fuel component, under sufficiently high pressures and temperatures experienced in the HPCR are prone to degradation irrespective of the concentration of the component in the original fuel. The most unstable component acts as the instigator, thus promoting fuel oxidation. The other components in the fuel such as FAME, aromatic and cycloalkane portions will also oxidise and eventually polymerise to form solids blocking the filter. This also demonstrates that while a large body of work on the oxidative instability of biodiesel in the chemical laboratory is indicative of instability this does not mimic what is seen under more realistic vehicle conditions and the focus on FAME instability is misleading.
Gopalan, Kesavan, Chuck, Christopher J., Roy-Smith, Christopher, Bannister, Christopher D.
Combustion Characteristics of Cottonseed Biodiesel and Chicken Fat Biodiesel Mixture in a Multi-Cylinder Compression Ignition Engine2019-01-00151/15/2019
Although waste animal fats such as chicken fat are promising alternative energy sources, biodiesels produced from these type of feedstocks hardly satisfies the EN14214 biodiesel standards. In this study, biomixtures were prepared by blending cottonseed biodiesel and chicken rendering fat biodiesel which were produced via transesterification method. Biodiesels were blended with each other at 60/40, 50/50 and 30/70 volume ratios to produce CO60CH40, CO50CH50 and CO30CH70 fuels. First, fuel properties of the neat biodiesels and novel biomixtures were measured and compared to European biodiesel standards and diesel. Then, the engine performance, combustion characteristics and exhaust emissions of these novel biomixture fuels were measured in a three-cylinder indirect injection diesel engine under various engine loads and at constant speed of 1500 rpm. The fuel characterisation showed that CO60CH40 and CO50CH50 biomixtures met the European standards. The Brake Specific Energy Consumption (BSEC) and Brake Thermal Efficiency (BTE) of all biomixtures were comparable with CO100, CH100 and diesel at the full engine load. The combustion results revealed that the maximum in-cylinder pressure and energy release values of the CO50CH50 were 4.2% and 4.4% higher than the diesel at full engine load because of optimised fuel properties of biomixture such as molecular structure, viscosity, cetane number and iodine value. CO50CH50 had 2.9% reduced CO2 and comparable CO emission compared to diesel, which were also 5.6% and 13% lower than cottonseed biodiesel respectively. However, NO emission of CO50CH50 was found 3.8% and 5.8% higher than diesel and cottonseed biodiesel. A 6.5% reduction on NO emission was observed when CO60CH40 biomixture fuel was used instead of diesel. To conclude, this research showed that blending of cottonseed and chicken fat biodiesels is a promising approach to meet the EN14214 standards, improve in-cylinder pressure, optimise energy release and reduce exhaust emissions. Blending of different biodiesels will be tested as a future work.
Masera, K., Hossain, A. K.
Integrated AHP and WED Based Approach to Select Optimal Combination of Operating Parameters on Spark Ignition Engine2019-01-00251/15/2019
The influence of operating parameters on the performance of spark ignition engine has attracted the interest of engine manufacturers and researchers. In this instance, selection of optimum criteria of operating parameters based on experimental results is expressed as a multi attribute decision making (MADM) problem. In this study, a mathematical model which is an integration of Analytic hierarchy process (AHP) and Weighted Euclidean distance based approach (WED) is proposed to select optimal combination of operating parameters. The parameters chosen are compression ratio (6,7,8,9), fuel blends (E10, E20, E30, E40) and load (25%, 50%, 75%, 100%). Consistency check of weights of attributes was carried out by AHP and the weighted distance of attributes from the most and least favorable situations was evaluated using WED. Optimum criteria with the combination of compression ratio of 8, fuel blend of E20 at load of 100% was found to be optimum. The results of proposed mathematical model were compared with another MCDM tool, Graph theory matrix approach. The proposed model allows the decision maker to analyze and evaluate the weights of attributes logically and systematically to make decision.
Geetha, Narayanan Kannaiyan, Pappula, Bridjesh
Future Fuels for DISI Engines: A Review on Oxygenated, Liquid Biofuels2019-01-00361/15/2019
Global warming and climate change have led to a greater interest in the implementation of biofuels in internal combustion engines. In spark ignited engines, biofuels have been shown to improve efficiency and knock resistance while decreasing emissions of unburned hydrocarbons, carbon monoxide and particles. This study investigates the effect of biofuels on SI engine combustion through a graphical compilation of previously reported results. Experimental data from 88 articles were used to evaluate the trends of the addition of different biofuels in gasoline. Graphs illustrating engine performance, combustion phasing and emissions are presented in conjunction with data on the physiochemical properties of each biofuel component to understand the observed trends. Internal combustion engines have the ability to handle a wide variety of fuels resulting in a broad range of biofuel candidates. Three groups of oxygenated liquid biofuels were investigated in this review: alcohols, ethers and furans. While the investigated alcohols showcase properties associated with increased engine efficiencies (such as higher chemical knock resistance, greater charge cooling and faster laminar flame speeds). They also pose the challenge of greater fuel consumption due to lower energy densities than gasoline. Ethers and furans, on the other hand are favored by current engine designs as they exhibit properties (such as the energy density) closer to gasoline alongside increased chemical knock resistance. The compiled data summarizes the possibilities to improve efficiency and fuel economy for biofuel and binary blends in SI engines. However, the results also, show that some of the trends are more complex than anticipated. The effect of biofuels on combustion speed, regulated emissions and exhaust temperatures are not proven to be as self-evident as reported in previous studies. Results on multiple blends with focus on the effect of blending on properties would help improve the picture of the effect of future fuels on SI combustion.
Larsson, Tara, Stenlaas, Ola, Erlandsson, Anders
Are Internal Diesel Injector Deposits (IDID) Mainly Linked to Biofuel Chemical Composition or/and Engine Operation Condition?2019-01-00611/15/2019
The increased use of alternative fuels has been linked to performance deterioration of injectors and engines as a result of internal diesel injector deposits (IDID). The present paper investigates fuel composition impact on injector tendency to blockage. Three main areas were investigated : (1) deposits linked to paraffins and aromatics content; (2) deposits linked to biodiesel composition using fatty acid methyl esters (FAME) and hydrotreated vegetal oil (HVO); and (3) deposits linked to the presence of additives (Dodecenylsuccinic anhydride DDSA, Dodecenyl Succinimid DDSI and Sodium Naphthenate). A deposit formation method was developed for the injection bench in order to discriminate the impact of fuels on system performance in terms of fuel volume injected, injection duration and stability. Three operation conditions were tested to represent low, intermediate and high load. In addition, the influence of soaking time and injector heating temperature was evaluated. The nature of the deposit was studied based on its morphology and chemical composition determined using Scanning Electron Microscopy coupled with Energy Dispersive X-ray (SEM/EDX) Spectroscopy. Deposits were observed for all fuels, even the highly paraffinic biofuel like HVO. Two main results are presented: Firstly, the main impact of fuel soaking period and high load operation on the occurrence of IDID, it was observed that deposit formation can be controlled by the time the fuel remains in contact with the hot metallic surface of the injector; Secondly, the complex correlation between deposit nature and characteristics and the injector’s tendency to blockage, for example, there is no straightforward link between deposit thickness and injector blockage, other parameters seem to be more appropriate to predict injector blockage. These are discussed in more detail in this study.
Alves Fortunato, Maira, Lenglet, Francis, Ben Amara, Arij, Starck, Laurie
Effect of EGR and Premixed Mass Percentage on Cycle to Cycle Variation of Methanol/Diesel Dual Fuel RCCI Combustion2019-26-00901/9/2019
Reactivity controlled compression ignition has been a proven combustion strategy for better reduction of NOx and PM emissions without compromising the fuel economy. However, the combustion strategy still need more investigation to overcome its operational stability. In this study, the influence of hot/cooled exhaust gas recirculation and premixed mass percentage and there cyclic variation of Methanol/Diesel dual fuel reactivity controlled compression ignition (RCCI) combustion was investigated in a modified 3 cylinder light duty, turbocharged, CRDI diesel engine. Methanol/Diesel RCCI combustion was achieved by premixing methanol with intake air in the intake port and injecting diesel directly into the cylinder by flexible common rail direct injection system. The intake manifold was altered to adopt port fuel injection of methanol and EGR. Experiments were conducted at 3.4 bar and 5.1 bar BMEP at 1500 rpm by varying EGR and premixed mass percentage. Overall, the results shows that 26% cooled EGR resulted in less cycle to cycle variation, better reduction in NO, and smoke emissions with improved thermal efficiency at both loads with methanol mass percentage 76% and 81% respectively. At hot EGR operation the higher cyclic variation, higher pressure rise rate and higher NOx and smoke emissions observed than cooled EGR operation. It is also observed that 5.1 bar BMEP operation exhibited a lesser cycle to cycle variation and emissions compared to 3.4 bar BMEP operation.
Duraisamy, Ganesh, Rangasamy, Murugan, Nagarajan, Govindan
Assessment on Performance, Combustion and Emission Characteristics of Diesel Engine Fuelled with Blends of Diesel, Algae Biodiesel and Heptanol2019-26-00911/9/2019
Because of higher NOx and PM emissions Compression Ignition (CI) engines are slowly being replaced by gas engines in metro cities though CI engine have better thermal efficiency and emit less Carbon monoxide (CO) and Unburned Hydrocarbons (UHC) emission than SI engines. Pollutants formed during combustion, depleting fossil fuels and continuous raising fuel price pushes the research community to find new alternative fuels which can be used along with diesel or replace the diesel without making major modifications in the current engine. The objective of this research work is to derive bio-diesel fuel from the source of algae and use it as a fuel by blending with commercially available diesel fuel. Heptanol is added along with algae bio-diesel and diesel blend to improve the ignition quality of the blend. Tests were conducted on a single cylinder constant speed, water cooled stationary diesel engine with different blends proportions of heptanol-biodiesel-diesel. The experimental results obtained for seven different types of blend proportions were compared with baseline diesel values. This research study reveals significant decrease in HC, CO, CO2 and NOx emission with marginal rise in smoke level. Amongst these seven samples, maximum of 14.7% NOx emission was reduced with S6 blend. At full load maximum Brake Thermal Efficiency (BTE) of 34.96% is also achieved with the same S6 blend which is a combination of 10% heptanol, 20% biodiesel and rest diesel. On overall comparison, sample S6 found to be better to operate in conventional diesel engine without any prior modification.
Saravanan, Supramani, Gupta, Sagar, Chidambaram, Rameshkumar, Jain, Aatmesh, Vora, Kamalkishore
Sugar-Powered Sensor Detects, Prevents DiseaseTBMG-3326411/1/2018
Researchers at Washington State University have developed an implantable, biofuel-powered sensor that runs on sugar and can monitor a body's biological signals to detect, prevent and diagnose diseases.
Influences of Butanol Blends on Combustion and Emissions of a Small SI Engine2018-32-005810/30/2018
In the general efforts to replace the fossil fuels in transportation by renewable fuels the bioalcohols are an important alternative. The global share of Bioethanol used for transportation is continuously increasing. Butanol, a four-carbon alcohol, is considered in the last years as an interesting alternative fuel, both for Diesel and for Gasoline application. Its advantages for engine operation are: good miscibility with gasoline and diesel fuels, higher calorific value than Ethanol, lower hygroscopicity, lower corrosivity and possibility of replacing aviation fuels. In the present work research with different nButanol portions in gasoline (BuXX)* was performed on the 2-cylinder SI engine with variations of several parameters on engine dynamometer. At different steady state operating points were varied: spark timing (αz), air excess factor (λ) and EGR-rate. Furthermore, the conversion rates and light-off of a 3-way-catalyst were investigated. As research tools the combustion pressure indication and the exhaust gas analysis were used. In the steady state operation, it was found that Bu-blends generally reduce the emissions of CO, HC, NOx in untreated exhaust gas and have a very little influence on catalytic conversion rates of the 3-way-catalyst. At lower engine part load, “Bu” shortens the inflammation lag and reduces the cyclic dispersion of combustion. Nevertheless, this advantage disappears at higher engine loads and with higher “Bu” portions. The present paper shows some examples of the most important results.
Czerwinski, Jan, Güdel, Martin, Engelmann, Danilo, Pechout, Martin
Waste Frying Oil Conversion to Biodiesel in Presence of Advanced Alumina Heterogeneous Catalyst2018-01-17509/10/2018
This paper reports experimental conversion of spent vegetable oil with bio-ethanol to long chain biodiesel fuel in presence of a new developed solid K3PO4 heterogeneous catalyst. Examined catalyst was synthesized following dipping impregnation of γ-Al2O3 solid support in an aqueous solution of potassium phosphate tri-basic K3PO4. K3PO4/γ-Al2O3 catalyst samples were distinguished based on their percentage loadings of K3PO4 (CK3PO4) and averaged particle size (dp). Produced catalyst samples were characterized in terms of their textural and surface properties using nitrogen adsorption-desorption isotherms and carbon dioxide & ammonia temperature programmed desorption techniques respectively. While the liquid phase of the product was analyzed using a GC-Mass spectroscopy technique. Ethanolysis runs were carried out following surface response methodology, central composite design (CCD). Parameters including catalyst percentage loading (CK3PO4), catalyst particle size (dp) as well as catalyst reactor weight (cat) were simulated the design factors. While percentage of ethyl ester yield (EEY%) was used as design response. Experimental results revealed an optimal measured EEY% of 92% achieved at 15:1 reactants molar ratio, 70 °C reaction temperature, 1000r.min−1 agitation speed, 25% percentage loading, 115 μm catalyst average particle size and 10 g/200 ml of catalyst weight in the reaction mixture. A high accuracy mathematical model was established for predicting the examined EEY% response results in terms of the above indicated operating parameters. Optimal EEY% of 95.43% was predicted under same operating conditions. The used catalyst was approved to be highly active, reliable and steady available solid heterogeneous catalyst that may promote the future of a more environmentally friendly biodiesel fuel.
Al-Zaini, Essam O., Abdullah, Ali A., Adesina, Adesoji
An Optical Study on the Combustion of Gasoline/PODEn Blends in a Constant Volume Vessel2018-01-17489/10/2018
Polyoxymethylene dimethyl ethers (PODEn) have high cetane number, high oxygen content and high volatility, therefore can be added to gasoline to optimize the performance and soot emission of Gasoline Compression Ignition (GCI) combustion. High speed imaging was used to investigate the spray and combustion process of gasoline/PODEn blends (PODEn volume fraction 0%-30%) under various ambient conditions and injection strategies in a constant volume vessel. Results showed that with an increase of PODEn proportion from 10% to 30%, liquid-phase penetration of the spray increased slightly, ignition delay decreased from 3.8 ms to 2.0 ms and flame lift off length decreased 29.4%, causing a significant increase of the flame luminance. For blends with 20% PODEn, when ambient temperature decreased from 893 K to 823 K, the ignition delay increased 1.3 ms and the flame luminance got lower. When increasing the injection pressure, the liquid phase length and the ignition delay got a little longer and the flame luminance and flame duration decreased. Long spray results showed that soot formed in higher PODEn flames oxidized earlier and quicker. The parameter changes that can extend the ignition delay all gave rise to the decrease of flame luminance because of the increase of the proportion of premixed combustion.
Ma, Yue, Cui, Longxi, Ma, Xiao, Wang, Zhi, Shuai, Shi-Jin
Dual Fuel Injection (DI + PFI) for Knock and EGR Dilution Limit Extension in a Boosted SI Engine2018-01-17359/10/2018
Combined direct and port fuel injection (i.e., dual injection) in spark ignition engines is of increasing interest due to the advantages for fuel flexibility and the individual merits of each system for improving engine performance and reducing engine-out emissions. Greater understanding of the impact of dual injection will enable deriving the maximum benefit from the two injection systems. This study investigates the effects of dual injection on combustion, especially knock propensity and tolerance to exhaust gas recirculation (EGR) dilution at different levels of EGR. A baseline for comparison with dual injection results was made using direct injection fueling only. A splash blended E20 fuel was used for the direct injection only tests. For the dual injection tests, gasoline, representing 80% by volume of the total fuel, was injected using the direct injector, and ethanol, representing 20% by volume of the total fuel, was injected using the port fuel injector. EGR mass fraction was varied from 0% to 21%, under boosted intake air pressure of 1.25 bar for both injection strategies. The results showed dual injection was beneficial to shorten the burn duration and improve combustion stability. Dual injection was more sensitive to knock than direct injection primarily due to increased unburned gas temperature. The overall thermal efficiency for the two injection types was comparable. The particulate matter emissions from dual injection showed slightly lower values, and the gaseous emissions showed lower total hydrocarbons and similar nitrogen oxides compared with only using direct injection of E20.
Han, Taehoon, Lavoie, George, Wooldridge, Margaret, Boehman, André
The Use of Ozone in Low Temperature Methane Control for Natural Gas Applications2018-01-17029/10/2018
Lean operating natural gas heavy duty applications have advantages in terms of lower CO2 and PM compared to Diesel applications. This makes operating heavy duty applications on natural gas attractive and currently, they do not have to implement an exhaust particulate filter. However, the challenge is controlling methane emissions over a range of vehicle operating conditions. Methane is extremely stable and light off occurs at temperatures above 400 °C, with high efficiency occurring >500 °C and requires high precious metal loaded catalysts in the range of 150 - 200 g/ft3. Under stoichiometric conditions, 500 °C can be met in many engine operating points however, for lean operating applications, the exhaust temperature can be significantly lower than 500 °C posing a significant challenge for exhaust catalytic CH4 control. This paper will discuss synthetic gas reactor study results using ozone in the feed gas to perform low temperature methane control. A range of catalysts were characterised for the development of low temperature methane control and a non-precious metal catalyst was found to give high efficiency at low temperatures. The best catalyst screened did not contain PGM and was a current production catalyst that gave >60% CH4 control at 220 °C, in the presence of water. All other catalysts screened gave no significant methane control activity at low temperatures. The feed gas composition played a key role in the peak efficiency obtained. The data shows a significant improvement in ozone enhanced catalysis compared to more traditional precious metal based CH4 control routes.
Keenan, Matthew, Nicole, Jacques, Poojary, Damodara
Effects of Injection Rate Profiles on Auto-Ignition in Ignition Quality Tester2018-01-16959/10/2018
Ignition quality tester (IQT) is a standard experimental device to determine ignition delay time of liquid fuels in a controlled environment in the absence of gas exchange. The process involves fuel injection, spray breakup, evaporation and mixing, which is followed by auto-ignition. In this study, three-dimensional computational fluid dynamics (CFD) is used for prediction of auto-ignition characteristics of diethyl ether (DEE) and ethanol. In particular, the sensitivity of the ignition behavior to different injection rate profiles is investigated. Fluctuant rate profile derived from needle lift data from experiments performs better than square rate profile in ignition delay predictions. DEE, when used with fluctuant injection rate profile resulted in faster ignition, while for ethanol the situation was reversed. The contrasting results are attributed to the difference in local mixing. The fluctuant injection profile yields larger spray velocity variations promoting fuel evaporation and local turbulent mixing. The suitable ignition conditions were reached earlier for DEE with fluctuant injection profile, whereas ethanol exhibits pseudo-homogeneous mixing due to its lower cetane number. Ignition was faster for square rate profile due to ignition in end tube for ethanol. The fluctuant injection leads to a better homogeneity for ethanol due to longer time available for mixing. The nature of heat release rate, auto-ignition and combustion were altered by the fluctuant injection rate profile when compared to square rate injection profile.
Luo, Yueqi, Mubarak Ali, Mohammed Jaasim, Huang, Zhen, Im, Hong
Experimental Investigation of the Effect of Karanja Oil Biodiesel with Cerium Oxide Nano Particle Fuel Additive on Lubricating Oil Tribology and Engine Wear in a Heavy Duty 38.8L,780 HP Military CIDI Diesel Engine2018-01-17539/10/2018
Biodiesel fuels are an alternative to diesel fuel. Biodiesel is an oxygenated, sulphur free, non-toxic, biogradable and renewable fuel. It is derived from vegetable oils. Since straight vegetable oils have quite high viscosity compared to mineral diesel, they have to be modified to bring their combustion-related properties and viscosity closer to mineral diesel. This is done by modifying their molecular structure through a transesterification process. In the present study, a military heavy duty 38.8 liter, 585 kW supercharged, compression ignition diesel injection (CIDI) engine was fuelled with diesel, Karanja oil methyl ester (KOME) biodiesel, and KOME biodiesel with cerium oxide fuel additive, respectively. These were subjected to 100 hours long term endurance tests. Lubricating oil samples, drawn from the engine fuelled with these fuels after a fixed interval of 20 hours, were subjected to elemental analysis. Atomic absorption spectroscopy was done for quantification of various metal debris concentrations. Lubricating oil samples were also subjected to ferrography test which indicated lower wear debris concentrations for a biodiesel with fuel additive operated engine. Number of tests was conducted in order to evaluate the comparative performances of these fuels such as lubrication measurement, density measurement, viscosity measurement, total base number etc. The experimental result showed that engine performance with Karanja oil biodiesel with fuel additive increased by 5%, along with lower gaseous emission including 14% - 25% lower NOx emission, and lower total particulate number concentration, as compared to diesel fuel The performance of biodiesel fuel is found to be superior to that of diesel oil. Also, the lubricating oil life is found to be longer while operating the engine on biodiesel with fuel additive. Engine metals wear were found 26% lower for a KOME biodiesel with cerium oxide fuel additive operated engine.
Pandey, Anand Kumar, Nandgaonkar, Milankumar, Pandey, Umang, Suresh, S
The Effect of Cerium Oxide Nano Particles Fuel Additive on Performance and Emission of Karanja Biodiesel Fueled Compression Ignition Military 585kW Heavy Duty Diesel Engine2018-01-18189/10/2018
Global warming with stringent emission legislation along with the depletion of fossil fuel has given us an opportunity to find biodiesel as alternative to diesel fuel. Biodiesel has been widely accepted as comparable fuel to diesel in diesel engine. This is due to its renewable property, better lubricity, along with lesser gaseous emission as compared to diesel fuel. However, there is a major disadvantage in the use of biodiesel as it increases NOx emission. Fuel additive becomes one of the essential tools to overcome the drawback of biodiesel required to meet the international standard of performance and emission. In this study, the performance, combustion, and gaseous emission of CO, CO2, HC, NOx and PM including particle size number distribution characteristics, were compared for diesel, Karanja oil biodiesel, and Karanja oil biodiesel with Cerium Oxide Nano particles fuel additive, in a 12 cylinder, 585 kW, CIDI military diesel engine. The experimental result showed that engine performance with Karanja oil biodiesel with fuel additive increased by 5%, along with lower gaseous emission including 14% - 26% lower NOx emission, lower particulate size number distribution, lower particle size surface area distribution, and lower total particulate number concentration, as compared to diesel fuel.
Pandey, Anand Kumar, Nandgaonkar, Milankumar, Pandey, Umang, Suresh, S, Varghese, Anil
Experimental Investigation on the Stabilizing Effect of n-Butanol on Diesel-Bioethanol Blends2018-01-17449/10/2018
In accordance to the current environmental policy of the European Union by 2020, 10% of the transport fuel in every country comes from renewable sources such as biofuels. One of the most popular biofuels, (bio) ethanol is a probable suitable candidate for addition in diesel fuel because of its cleaner combustion and the ability to reduce emissions of gaseous pollutants. However, its use presents some important problems, attributed mainly to its incompatibility with diesel fuel during mixing due to the difference in the polarity. For this reason, substances that act as stabilizers of these mixtures are used, one of the most suitable being butanol. This substance is compatible with diesel fuel and ethanol, acting as a chemical bridge between the two, but also exhibits positive combustion behavior, as it is also an oxygenate that can be produced from renewable sources as well. The aim of this work was to investigate the behavior of diesel-ethanol mixtures using butanol as co-solvent. Different ultra low sulfur diesel (ULSD) samples, as well as a renewable paraffinic fuel derived from hydrotreatment of vegetable oils (HVO) were used as base fuels for the preparation of diesel - ethanol blends, with the addition of n-butanol as co-solvent. The main idea was to produce stable blends that can be used as fuel in diesel engines. The results showed that the production of stable diesel - bioethanol - butanol ternary blends is feasible. The amount of butanol that is required depends on the composition of the main fuel, with the aromatic content of the base fuel to be a critical parameter. Oxidation stability of the stable ternary blends was also evaluated in a Rapid Small Scale Oxidation Test unit, while other properties, such as ignition quality, were also measured. The results showed that the addition of the two oxygenates affect the oxidative characteristics of the base fuel, whereas a decrease in cetane number was observed.
Karonis, Dimitrios, Zahos Siagos, Iraklis, Pavlopoulos, Spyridon, Dodos, George S.
Comparison of Primary Sensitive Reactions on Fuel Reactivity between Detailed and Skeletal Mechanisms of Gasoline Surrogate2018-01-17379/10/2018
Combustion simulation is of great importance for internal combustion engine development. With the advance of fundamental combustion experiments and theoretical computation, detailed combustion mechanisms of gasoline surrogates have been enhanced with introduction of new reactions and updated reaction rate constants recently. However, detailed combustion mechanisms with tens of thousands of reactions are still not practical for engineering use in view of massive computation cost. As a practical alternative, skeletal mechanisms are usually developed to couple with three dimensional engine combustion simulations. As for skeletal mechanisms, rate constants of some important reactions have to be tuned to reproduce the experimental data due to the omission of intermediate reaction steps, thus are different from those applied in detailed mechanisms. However, whether the skeletal mechanism reproduces the combustion reaction process with similar major reactions as the detailed mechanisms is rarely studied. Therefore, the aim of this study is to investigate the different sensitive reactions between the detailed and skeletal mechanisms that affect the fuel reactivity with brute force sensitivity analysis. Results show that the detailed mechanism predicts more strong negative temperature coefficient behavior than the skeletal mechanism. Similar ignition delays were predicted by both mechanisms around 700 K, while the significant difference occurred around 825 K. For the skeletal mechanism, reactions with rate constants altered by one to three orders could change their role of controlling the fuel reactivity as in the detailed mechanism, and also substantially affect the first stage ignition process. Therefore, procedure for reaction rate constant tuning with optimization directions should be proposed in the future for constructing skeletal mechanisms that could reproduce the combustion characteristics of fuels with similar reactivity controlling reactions as in the detailed mechanisms.
Meng, Xiangzan, Meng, Yi
Combustion Characteristics of PRF and TSF Ethanol Blends with RON 98 in an Instrumented CFR Engine2018-01-16729/10/2018
The CFR F1 engine is the standard testing apparatus used for rating the research octane number (RON) of gasoline fuels. Unlike the motor octane number (MON) method, where the intake port temperature after the carburetor is controlled by an electric heater, the mixture temperature can vary during the RON test due to the heat of vaporization (HoV) of the fuel. Ethanol is receiving increasing attention as a high octane and high HoV fuel component. This work presents an analysis of the combustion characteristics during the RON rating of ethanol fuel blends according to the standard ASTM D2699 method, highlighting the effects of ethanol concentration and base fuel composition. All fuels were blended to a constant RON of 98. Ethanol levels varied from 0 to 50 vol% and the base fuels were surrogate blends composed of primary reference fuels (PRF), toluene standardization fuels (TSF), and a four component gasoline surrogate. These were compared against two full boiling range gasolines, also having a RON of 98. Through the use of detailed cylinder pressure analyses, this paper provides insights into the combustion behavior of various RON 98 fuels which are commonly not captured by the standard RON knock rating method. Ethanol was found to significantly reduce the pressure transducer based knock intensity of PRF fuel blends up to a level of 30 vol%, despite all fuels having the same RON. Meanwhile, the knock intensity of the equivalent TSF fuel blends was found to be relatively insensitive to ethanol concentration. For ethanol concentrations beyond 30 vol%, the pressure transducer based knock intensity behavior did not appear to be affected by the base fuel composition.
Hoth, Alexander, Kolodziej, Christopher P., Rockstroh, Toby, Wallner, Thomas
Characterization of Hydroprocessed Used Cooking Oils as High Cetane Number Blending Component for Automotive Diesel2018-01-17459/10/2018
Renewable substitutes for transportation fuels have had an important role in the recent years. Hydrotreated vegetable oils (HVO) are produced from two stage hydrotreating process of vegetable oils. The second stage of this hydroteating process is used to convert normal paraffins to isoparaffins in order to improve cold flow properties of these fuels. As this stage is a high energy consuming process, it is of interest to investigate the characteristics and the usability of the first stage of hydrotreatment of lipids. This paper examines the properties of alternative fuel derived from the hydrotreatment of used cooking oil (UCO). Used cooking oil is a difficult feedstock for biodiesel production. The hydrotreating of UCO converts triglycerides mainly into normal paraffins within the diesel fuel range. The hydrotreated UCO (HUCO) has an excellent cetane number and cetane index (>90), but very poor cold flow properties. As the amount of the produced HUCO is limited, the main idea is to use it in blends with petroleum diesel fuel. For this reason, the HUCO was blended with ultra-low diesel fuel (ULSD) and low cetane number high aromatic middle distillate. The results showed that ternary blends of these fuels can produce fuel that meets the specifications set by EN 590 standard, mainly summer grade fuel, as the poor cold flow properties of the HUCO affect negatively the cold flow properties of the blend. The lubricity of the HUCO does not meet EN 590 standards, but the blends have improved lubricating characteristics, within specification limits.
Karonis, Dimitrios, Zahos Siagos, Iraklis, Bezergianni, Stella
Critical Analysis of PM Index and Other Fuel Indices: Impact of Gasoline Fuel Volatility and Chemical Composition2018-01-17419/10/2018
Among the challenges for the future facing the development of gasoline engines, one of the most important is the reduction of particles emissions. This study proposes a critical and objective evaluation of the influence of fuel characteristics on gasoline particles emission through the use of Fuel Particle Indices. For this, a selected fuel matrix composed of 22 fuels was built presenting different volatility and chemical composition (content in total aromatics, heavy cuts and ethanol). To represent the fuel sooting tendency, seven Fuel Particle Indices were selected based on a literature review, namely, Particulate Matter Index (PMI), Particulate Number index (PNI), Threshold Sooting index (TSI), Smoke point (SP), Oxygen Extended Sooting Index (OESI), Simplified index 1 and 2 (sPMI 1, sPMI 2). These indices were computed on the fuel matrix and compared on the basis of three main axes. First, the sensitivity to fuel variation. Second, the agreement with engine particles emissions measured on vehicle on three vehicles. Third, the ease to compute with respect to the data availability in the European standard EN228. The comparison of fuel particles indices revealed different sensitivities to fuel variation: PMI, sPMI 1 and sPMI 2 represent well the effects of heavy aromatics, PNI is highly sensitive to the DVPE whereas SP, OESI and TSI were found well representative of the total aromatic content but represent weakly the effect of heavy aromatics. The comparison of the fuel particles indices with engine data indicates a good agreement of all indices, except for PNI. Finally, sPMI 1, sPMI 2 and calculated SP were found to be much easier to compute because they need simple data as input. This work highlights the importance of fuel quality on the reduction of particles emissions and suggests relevant Fuel Particles Indices that allow to capture fuel variation.
Ben Amara, Arij, Tahtouh, Toni, Ubrich, Elisabeth, Starck, Laurie, Moriya, Hidenori, IIda, Yutaka, KOJI, Nagata
Effects of Bio-Alcohol Fuel Blends on the Aging of Engine Lubricating Oil2018-01-17469/10/2018
Bio-alcohol fuel blends will gain in importance for future mobility. The driving force is the necessary reduction of greenhouse gases and harmful exhaust gas components. The new fuels offer advantages in engine combustion and resulting exhaust emissions because of the short-chained molecules and resulting low C/H ratio as well as the higher oxygen content. The aim of the project is a systematic analysis and evaluation of the effects of two bio-alcohol blends on the lubrication oil ageing of a gasoline-driven Euro 6 passenger car engine. For this reason a test engine was operated with three different fuels: a fossil gasoline (E0) without bio-alcohol components, a blend containing 30% vol ethanol (E30) and a blend containing 15% vol methanol (M15). During the engine test, gas of the cylinder charge and blow-by has been sampled and analyzed by ion chromatography regarding short-chained organic and inorganic acids. Based on these results the acid entries in lubricating oil were determined. In addition to the acid entries the entry of fuel into the lubricating oil were determined and compared for different engine operation points and test fuels. The causes of the fuel entries are discussed, based on the different fuel compositions and the resulting properties of bio-alcohol fuel blends. The results of the project provide detailed insights in the influence of the bio-alcohol fuel blends lubricity and aging of engine lubricating oil. This knowledge is prerequisite for a successful introduction of fuels with higher amounts of bio-alcohol in the market to meet the target for carbon dioxide reduction in the future mobility sector.
Prehn, Sascha, Vogel, Christine, Buchholz, Bert
Diesel Fuel Improvers and Their Effect on Microbial Stability of Diesel/Biodiesel Blends2018-01-17519/10/2018
Additives that enhance properties, such as cetane number or cold flow, are introduced in diesel-biodiesel blends in order to upgrade its performance as well as to aid its handling and distribution. Furthermore, in order to protect the engine and fuel operating system equipment, diesel fuel may be treated with corrosion inhibitors and detergents. However, additives could also have an impact on other parameters beyond those that they are intended to boost. In the present study the effect of diesel fuel improvers on fuel’s microbial stability is examined. An additive-free ultra low sulfur diesel (ULSD) was blended with Soybean Fatty Acid Methyl Esters (FAME) and the resulting blend was treated separately with a series of commercially available diesel fuel additives. Specific products belonging to the groups of cold-flow improvers, cetane improvers, metal deactivators and corrosion inhibitors were employed and were added both at the recommended treating rate as well as in a range of concentrations (1000, 250 and 500 ppm). Following to this, the impact of those agents on microbial proliferation in diesel fuel was studied under certain testing protocols for detecting and evaluating substances that could inhibit fuel biodeterioration. Overall, the results demonstrate that certain additives primarily added to diesel fuel in order to improve its performance contain substances that are non-supportive to bacterial proliferation.
Tsesmeli, Chrysovalanti, Dodos, George S., Zannikos, Fanourios
The Choice of a Rational Type of Fuel for Technological Vehicles2018-01-17599/10/2018
The article deals with the results of experimental and theoretical studies of the technological vehicle during its work on various types of fuel. The purpose of the work is to choose a rational type of fuel or an energy source for vehicles according to one general criterion. The feature of the proposed methodology is that the indicators of fuel and engine are estimated by the criterion of adaptability of technique to a particular type of fuel. A new approach to environmental safety assessment of technological vehicles while working on different fuels by environmental criterion taking into account the amount of emissions of harmful substances, their maximum permissible concentrations and hazard class. The economic efficiency in the operation of vehicles on alternative fuels is estimated by the criterion of economic efficiency. Fuel consumption and emissions of harmful substances of the engine 4FS 11.0/12.5 at various speed and loading modes when working on different fuels were determined in the experimental method. The obtained characteristics of the engine for their use in the mathematical model of motion of the vehicle were described by polynomial dependencies. Quantitative values of fuel consumption and emissions of harmful substances in the process of moving a technological vehicle for a ride cycle using various types of fuels were obtained by method of mathematical modeling. The analysis helps to define the efficient type of the fuel in accordance with the above mention criteria. Natural gas has the greatest value for choosing the appropriate fuel type. Less criterion is used for biodiesel fuel, the lowest value criterion is appropriate for petroleum diesel fuel.
Zaharchuk, Victor, Gritsuk, Igor V., Zaharchuk, Oleg, Golovan, Andrii, Korobka, Sergey, Pylypiuk, Larisa, Rudnichenko, Nickolay
A Computational Study of Lean Limit Extension of Alcohol HCCI Engines2018-01-16799/10/2018
The purpose of present numerical study was to extend the operating range of alcohol (methanol and ethanol) fueled Homogeneous Charge Compression Ignition (HCCI) engine under low load conditions. Ignition of pure methanol and ethanol under HCCI mode of operation requires high intake temperatures and misfires at low loads are common in HCCI engines. Three methods have been adapted to optimize the use of methanol and ethanol for HCCI operation without increasing the intake temperature. First, blending methanol and ethanol with ignition improver, namely di-methyl ether (DME) and di-ethyl ether (DEE), was used to increase the cetane number and ignitability of premixed charge. Second, based on the blended fuels, the spark assistance was used to reduce required intake temperature for auto-ignition. Third, DME and DEE were directly injected to methanol and ethanol operated HCCI engine, in the form of Reactivity Controlled Compression Ignition (RCCI) combustion. Negligible improvement in reducing intake temperature was observed in spark-assisted HCCI combustion due to the slow flame propagation speed under the lean premixed condition with blended fuels. In all three methods, it was found that RCCI combustion was more effective at reducing the required intake temperature compared to HCCI and spark assisted combustion, in spite of the fact that they are operated at same lambda (3.3) operating conditions.
Zhou, Qiyan, Mubarak Ali, Mohammed Jaasim, Mohan, Balaji, Lu, Xing-Cai, Im, Hong
Crank-Angle Resolved Exergy Analysis of Ethanol Fueled HCCI Engine Using Newly Reduced Ethanol Oxidation Mechanism2018-01-16839/10/2018
Ethanol fuelled homogenous charge compression ignition engine (HCCI) offers a better alternative to tackle the problems of achieving higher engine efficiency and lower emissions. Numerical simulations were carried out for a HCCI engine fueled with ethanol by stochastic reactor model using newly developed reduced ethanol oxidation mechanism consists of 47 species and 272 reactions. Reduced mechanism used in this study is validated by measured engine cylinder pressure curves and measured ignition delays in constant volume reactors in the previous study. Simulations are conducted for engine speeds ranging from 1000 to 3000 rpm at different intake temperatures (range 365-465 K) by varying the air-fuel ratio. Parametric study for combustion and emission characteristics is conducted and engine maps are developed at most efficient inlet temperatures. The HCCI operating range is defined using combustion efficiency (>85%) and maximum pressure rise rate (<5 MPa/ms). Areas of operation where excessive exergy destruction occurred were recognized using analyses of availability losses from exhaust, heat transfer, unburnt species and destruction due to combustion using engine operating maps. Availability destruction due to combustion is found to be maximum at high engine loads and high engine speeds. The maxima of losses of availability due to heat transfer and unburnt species are observed at low engine speeds and loads. In contrast to the mentioned losses, exhaust based loss of availability has its vertex at the highest achieved engine loads.
Maurya, Rakesh Kumar, Jaggi, Parth, Saxena, Mohit Raj
Blending Octane Number of 1-Butanol and Iso-Octane with Low Octane Fuels in HCCI Combustion Mode2018-01-16819/10/2018
Due to their physical and chemical properties, alcohols such as ethanol and methanol when blended with gasoline provide high anti-knock quality and hence efficient engines. However, there are few promising properties of 1-butanol similar to conventional gasoline which make it a favorable choice for internal combustion engines. Previously the author showed that by blending ethanol and methanol with low octane fuels, non-linear increase in the HCCI fuel number occurs in HCCI combustion mode. Very few studies have been conducted on the use of 1-butanol in HCCI combustion mode, therefore for this work, 1-butanol with a RON 96 was selected as the high octane fuel. Three low octane fuels with octane number close to 70 were used as a base fuel. Two of the low octane fuels are Fuels for Advanced Combustion Engines (FACE gasolines), more specifically FACE I and FACE J and also primary reference fuel (PRF 70) were selected. In addition, iso-octane, which has a different chemical structure than 1-butanol but an octane number (100) close to 1-butanol, was also selected as high octane fuel. A Cooperative Fuel Research (CFR) engine was used to conduct the experiments in HCCI combustion mode. HCCI fuel number was used for the octane rating similar to RON and MON in SI engine. 1-butanol and iso-octane were added in volume percentage 0, 5, 10, 15 and 20% to each of the base fuels. It was found that the increase of HCCI fuel number of 1-butanol was not linear with percentage added. For most of the operating conditions, non-linear synergistic blending behavior was observed when 1-butanol was blended with the three base fuels. The base fuel composition played a significant role for the blending octane number of 1-butanol. A weaker octane enhancement effect was observed when iso-octane was blended with the three base fuels.
Waqas, Muhammad Umer, Mohammed, Abdulrahman, Masurier, Jean-Baptiste, Johansson, Bengt
Heat Loss Analysis for Various Piston Geometries in a Heavy-Duty Methanol PPC Engine2018-01-17269/10/2018
Partially premixed combustion (PPC) in internal combustion engine as a low temperature combustion strategy has shown great potential to achieve high thermodynamic efficiency. Methanol due to its unique properties is considered as a preferable PPC engine fuel. The injection timing to achieve methanol PPC conditions should be set very close to TDC, allowing to utilize spray-bowl interaction to further improve combustion process in terms of emissions and heat losses. In this study CFD simulations are performed to investigate spray-bowl interaction for a number of different piston designs and its impact on the heat transfer and the overall piston performance. The validation case is based on a single cylinder heavy-duty Scania D13 engine with a compression ratio 15. The operation point is set to low load 5.42 IMEPg bar with SOI -3 aTDC. After satisfactory agreement with experiments in terms of combustion phasing, in-cylinder pressure and heat release rate, the effect of piston bowl geometry is investigated by performing several CFD simulations with modified piston bowl geometry while keeping the compression ratio, CA50 and injection conditions the same as the baseline case. The influence of the wall temperature gradient, the near wall effective conductivity and the piston bowl area on the heat transfer is studied. It was observed that the flow structures that re-direct the hot vapor away from the in-cylinder walls will reduce the wall area that actively transfer the heat. The final piston performance comparison showed that piston bowl designs with a reduced area to volume ratio does not guarantee lower heat loss. Therefore, the mixing process as the result of the spray-bowl interaction and the resulting fuel distribution are considered as the main mechanisms to minimize the total heat losses.
Pucilowski, Mateusz, Jangi, Mehdi, Shamun, Sam, Tuner, Martin, Bai, Xue-Song
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