Search Results

Recent work has demonstrated the potential of gasoline-like fuels to reduce NOx and particulate emissions when used in compression ignition engines. In this context, low research octane number (RON) gasoline, a refinery stream derived from the atmospheric crude oil distillation process, has been identified as a highly valuable fuel. In addition, thanks to its higher H/C ratio and energy content compared to diesel, CO2 benefits are also expected when used in such engines. In previous studies, different cetane number (CN) fuels have been evaluated and a CN 35 fuel has been selected. The assessment and the choice of the required engine hardware adapted to this fuel, such as the compression ratio, bowl pattern and nozzle design have been performed on a single cylinder compression-ignition engine.

Fuels from crude oil are the main energy vector used in the worldwide transport sector. But conventional fuel and engine technologies are often criticized, especially Diesel engines with the recent “Diesel gate”. Engine and fuel co-research is one of the main leverage to reduce both CO2 footprint and criteria pollutants in the transport sector. Compression ignition engines with gasoline-like fuels are a promising way for both NOx and particulate emissions abatement while keeping lower tailpipe CO2 emissions from both combustion process, physical and chemical properties of the low RON gasoline. To introduce a new fuel/engine technology, investigation of pollutants and After-Treatment Systems (ATS) is mandatory. Previous work [1] already studied soot behavior to define the rules for the design of the Diesel Particulate Filter (DPF) when used with a low RON gasoline in a compression ignition engine.

Reducing the CO2 footprint, limiting the pollutant emissions and rebalancing the ongoing shift demand toward middle-distillate fuels are major concerns for vehicle manufacturers and oil refiners. In this context, gasoline-like fuels have been recently identified as good candidates. Straight run naphtha, a refinery stream derived from the atmospheric crude oil distillation process, allows for a reduction of both NOx and particulate emissions when used in compression-ignition engines. CO2 benefits are also expected thanks to naphtha’s higher H/C ratio and energy content compared to diesel. In previous studies, wide ranges of Cetane Number (CN) naphtha fuels have been evaluated and CN 35 naphtha fuel has been selected. The assessment and the choice of the required engine hardware adapted to this fuel, such as the compression ratio, bowl pattern, nozzle design and air-path technology, have been performed on a light-duty single cylinder compression-ignition engine.

Adaptation of both oil based fuel and engine technologies are key enablers to reduce CO2 footprint as well as pollutant emissions. Recent work has demonstrated the potential of gasoline-like fuels to reduce NOX and particulate emissions when used in compression ignition engines. In addition, properties of naphtha produced directly from the atmospheric crude oil distillation process in a refinery offer significant CO2 benefits. When introducing such innovative fuel and engine, after-treatment investigations are mandatory to meet pollutant regulations. In that respect, this work focuses on investigating structure and properties of the particulates produced with naphtha fuel to validate Diesel Particulate Filter (DPF) design requirements. First, soot mass measurement techniques are detailed. Then, characterization of soot is performed through DPF pressure drop, soot oxidation rates with and without Fuel Borne Catalyst (FBC), composition & structure analysis.

Gasoline-like fuels have been recently identified as good candidates to reduce NOX and particulate emissions when used in compression-ignition (CI) engines. In this context, straight-run naphtha, a refinery stream directly derived from the atmospheric crude oil distillation process, was identified as a highly valuable fuel. In addition, thanks to its higher H/C ratio and energy content (LHV) compared to diesel, CO2 benefits are also expected when using naphtha in such engines. In a previous study, wide ranges of Cetane Number naphtha fuels (CN 20 to 35) were evaluated to optimize CI combustion, with different bowls and nozzle designs. CN 35 naphtha fuel has been selected for its better robustness and lower HC and CO emissions. The purpose of the current study is to investigate the potential of CN 35 naphtha fuel on a light duty single-cylinder compression-ignition engine as well as the minimum required hardware modifications needed to properly run this fuel.

Recent work has demonstrated the potential of gasoline-like fuels to reduce NOX and particulates emissions when used in diesel engines. Indeed, fuels highly resistant to auto-ignition provide more time for fuel and air mixing prior to the combustion and therefore a more homogeneous combustion. Nevertheless, major issues still need to be addressed, particularly regarding UHC and CO emissions at low load and particulate/noise combustion trade-off at high load. The purpose of this study is to investigate how an existing modern diesel engine could be operated with low-cetane fuels and define the most appropriate Cetane Number (CN) to reduce engine-out emissions. With this regard, a selection of naphtha and gasoline blends, ranging from CN30/RON 57 to CN35/RON 41 was investigated on a Euro 5, 1.6L four-cylinder engine. Results were compared to the conventional diesel running mode using a minimum NOX level oriented calibration, both in steady state and transient conditions.