Rankovic N.,Aramco Fuel Research Center |
Bourhis G.,French Institute of Petroleum |
Loos M.,French Institute of Petroleum |
Dauphin R.,French Institute of Petroleum
Fuel | Year: 2015
Most of the time, spark ignition (SI) engine performance is limited by knock phenomena (especially for turbocharged engines), which are linked to fuel resistance to auto-ignition, quantified by its octane number (Research Octane Number - RON and Motor Octane Number - MON). If high octane numbers are crucial for efficient high load operating points, they are less necessary at low load. Thus, if the octane number of the fuel could be tuned as any other engine setting parameter, the engine efficiency and CO2 emissions could be improved, leading to an "Octane on Demand" concept, using for instance a dual fuel strategy. This requires understanding the behavior of dual fuel combustions with lower/higher octane fuels, and more particularly the evolution of RON when blending high RON fuels with low RON ones. Developing an Octane on Demand concept requires to choose appropriate octane enhancers and understand their blending behavior. For this purpose, RON measurements were performed on a CFR engine using a wide range of mixtures of low-octane base fuels with various boosters capable of increasing the antiknock resistance of the blends. The chemical composition of booster streams was chosen to assess the potential of using alternative refinery products for improving fuel resistant auto-ignition properties when added to a whole-range naphtha and RON 91 gasoline. The study covers five octane boosters: ethanol, reformate, di-isobutylene, 2-butanol, and a mixture of butanols. The experimental results show a non-linear behavior of RON values with respect to volumetric incorporation rates of octane boosters. In the cases when the booster is an alcohol (C2 or C4), linear by-mole blending rules can be applied with an acceptable prediction error. For boosters rich in olefins and aromatics, molar blending becomes less accurate. Ethanol shows the strongest boosting effect among all the octane boosters on the one hand, and on the other hand, the octane enhancing effect is stronger for the base fuel of lower starting RON value. Experimental results of the current study represent a comprehensive database for tailoring fuel RON properties aimed to explore combustion behavior of low-octane fuels enhanced through an addition of an external booster. © 2015 Elsevier Ltd.
Rankovic N.,French Institute of Petroleum |
Rankovic N.,University Pierre and Marie Curie |
Rankovic N.,Aramco Fuel Research Center |
Chizallet C.,French Institute of Petroleum |
And 2 more authors.
Industrial and Engineering Chemistry Research | Year: 2013
The present paper presents a multiscale (DFT to mean-field) modeling approach for describing barium sulfate formation through the adsorption of sulfur oxides on BaO. Sulfur oxide emissions, a major environmental concern, also represent one of the technological issues for a large-scale implementation of alkaline-earth oxides as NOx abatement techniques for vehicle exhaust depollution. SOx adsorption was studied at the atomic level on various BaO sites (terraces, surface defects, and bulk) for a closer description of a real storage material. Ab initio data were used to conceive a kinetic model for SOx adsorption that allows us to follow species adsorption and desorption dynamics. Our results confirm that sulfur oxides interact strongly with the NOx trapping material to form thermodynamically favored sulfate species, consequently leading to the blockage of NOx sorption sites and altering the storage properties. © 2013 American Chemical Society.
Morel V.,Aramco Overseas Company |
Morel V.,Aramco Fuel Research Center |
Francqueville L.,French Institute of Petroleum |
Laget O.,French Institute of Petroleum |
And 2 more authors.
SAE Technical Papers | Year: 2016
Recent work has demonstrated the potential of gasoline-like fuels to reduce NOx and particulate emissions when used in Diesel engines. In this context, straight-run naphtha, a refinery stream directly derived from the atmospheric crude oil distillation process, has been identified as a highly valuable fuel. The current study is one step further toward naphtha-based fuel to power compression ignition engines. The potential of a cetane number 25 fuel (CN25), resulting from a blend of hydro-treated straight-run naphtha CN35 with unleaded non-oxygenated gasoline RON91 was assessed. For this purpose, investigations were conducted on multiple fronts, including experimental activities on an injection test bed, in an optically accessible vessel and in a single cylinder engine. CFD simulations were also developed to provide relevant explanations. Among multiple results, evaluation of full-load performance on the single cylinder engine showed that with a conventional nozzle configuration designed for Diesel fuel, CN25 was able to meet the maximum low-end torque target. However, at maximum power rate, a 15% power loss was noted. CFD results revealed a poor fuel distribution between the piston bowl and the squish area, a difficulty that was overcome by increasing the hydraulic flow of the nozzle along with the number of injector holes. At part load, an optimization was carried out on six operating points, and dedicated injection strategies were established to properly manage the combustion. Finally, global assessments performed on the WLTC cycle showed encouraging results: 5% CO2 emission reduction was measured compared to Diesel while achieving an engine-out NOx and particulates level compliant with Euro 6 standard (no NOx after treatment but DPF requested). Excessive UHC and CO emissions were nevertheless measured (UHC∗2.5 and CO∗1.1). Dedicated efforts are still in progress to further reduce these, mainly by adapting the cetane number of the fuel to within the range 30-35. © Copyright 2016 SAE International.
News Article | November 14, 2015
« 2016 Hyundai Sonata Plug-In Hybrid coming to market with EPA-estimated 27-mile electric range; starts at $34,600 | Main | VW: 430,046 MY 2016 vehicles in Europe affected by “CO2 issue” » The Aramco Research Center-Detroit was inaugurated as one of three US-based research and development (R&D) centers aimed at expanding the global research capabilities of Saudi Aramco, the leading global integrated energy and chemicals company. The new facility, located in Novi, Mich., and owned and operated by US subsidiary Aramco Services Company, further strengthens the company’s global fuels research program. Aramco’s fuels technology program is focused on reducing the overall environmental impact, cost and complexity of both current and future fuel-engine systems. With a global refining presence, Aramco brings a perspective into how fuels can be designed and matched to engines for higher performance and lower emissions. A planned outcome of Aramco’s research is to generate vehicle and fleet demonstrations to showcase the benefits of novel fuel/engine systems. Specific areas of research being conducted at Aramco’s new Detroit center include fuel combustion and emissions, technology integration and strategic transport studies. The research center is tasked with developing, demonstrating and showcasing low-carbon-footprint transportation technologies, in support of reducing CO emissions from transport sources. The 50,000-square-foot Detroit research center is equipped with four state-of-the-art engine dynamometer labs, and in mid-2016, a vehicle integration lab featuring a chassis dynamometer for evaluating engine performance and identifying solutions to all types of system integration challenges. This includes ensuring that new technologies will meet vehicle performance and emissions specifications in a wide range of certification cycles under cold (20°F) and hot (120°F) conditions. Substantial flexibility has been built into the lab’s capabilities surrounding fuel design, fuel procurement and specialty fuel distribution, including providing 12 independent fuel lines to the labs—which allows back-to-back advanced fuel testing and blending. The facility’s research capacity encompasses very small engines such as a single-cylinder research engine to 1,000 horsepower heavy-duty on-road and stationary engines. Aramco’s global fuels research network encompasses Aramco’s Research & Development Center in Dhahran, Saudi Arabia; a partnership with the Clean Combustion Research Center at the King Abdullah University of Science and Technology in Thuwal, Saudi Arabia; and the Aramco Fuel Research Center, Paris, with the French petroleum research institute IFPEN. US subsidiary Aramco Services Company’s other research centers are: the Aramco Research Center-Boston, in Cambridge across the street from MIT; and the Aramco Research Center-Houston, in the city’s northwest area Energy Corridor. Aramco’s other research facilities are located in Aberdeen; Delft, The Netherlands; Daejeon, Korea; Paris; and Beijing; as well as Dhahran and Thuwal, Saudi Arabia. The research centers are closely aligned with the company’s award-winning research organizations: the Exploration and Petroleum Engineering Center’s Advanced Research Center and the Research & Development Center located in Dhahran, Saudi Arabia.