| 1. |
- Hermann, Fredrik, et al.
(författare)
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Chemical analysis of combustion products from a high-pressure gas turbine combustor rig fueled by jet A1 fuel and a Fischer-Tropsch-based fuel
- 2006
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Ingår i: Proceedings of the ASME Turbo Expo. - 0791842363 ; 1, s. 523-532
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Konferensbidrag (refereegranskat)abstract
- A comparative experimental investigation has been performed, comparing the emissions from a synthetic jet fuel and from Jet AI. In the investigation, the unburned hydrocarbons were analyzed chemically and the regulated emissions of NOX, CO and HC were measured. All combustion tests were performed under elevated pressures in a gas turbine combustor rig. A Swedish company, Oroboros AB, has developed a novel clean synthetic jet fuel, LeanJet [registered trademark] . The fuel is produced synthetically from synthesis gas by a Fischer-Tropsch process. Except for the density, the fuel conforms to the Standard Specification for Aviation Turbine Fuels. The low density is due to the lack of aromatics and polyaromatics. Organic emissions from the gas turbine combustor rig were collected by adsorption sampling and analyzed chemically. Both the fuels and the organic emissions were analyzed by gas chromatography/flame ionization (GC/FlD) complemented with gas chromatography/mass spectrometry (GC/MS). Under the operating conditions investigated, no significant differences were found for the regulated emissions, except for emission of CO from the synthetic fuel, which, at leaner conditions, was one-quarter of that measured for Jet Al. Detailed analysis of the organic compounds showed that the emissions from both fuels were dominated by fuel alkanes and a significant amount of naphthalene. It was also found that Jet Al produced a much higher amount of benzene than the synthetic fuel. Copyright
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| 2. |
- Hermann, Fredrik, et al.
(författare)
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Chemical analysis of combustion products from a high-pressure gas turbine combustor rig fueled by jet A1 fuel and a flscher-tropsch-based fuel
- 2006
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Ingår i: Proceedings of the ASME Turbo Expo 2006 - Power for Land, Sea, and Air. - 0791842363 - 9780791842362 - 0791837742 ; 1, s. 523-532
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Konferensbidrag (refereegranskat)abstract
- A comparative experimental investigation has been performed, comparing the emissions from a synthetic jet fuel and from Jet AI. In the investigation, the unburned hydrocarbons were analyzed chemically and the regulated emissions of NOX, CO and HC were measured. All combustion tests were performed under elevated pressures in a gas turbine combustor rig. A Swedish company, Oroboros AB, has developed a novel clean synthetic jet fuel, LeanJet®. The fuel is produced synthetically from synthesis gas by a Fischer-Tropsch process. Except for the density, the fuel conforms to the Standard Specification for Aviation Turbine Fuels. The low density is due to the lack of aromatics and polyaromatics. Organic emissions from the gas turbine combustor rig were collected by adsorption sampling and analyzed chemically. Both the fuels and the organic emissions were analyzed by gas chromatography/flame ionization (GC/FlD) complemented with gas chromatography/mass spectrometry (GC/MS). Under the operating conditions investigated, no significant differences were found for the regulated emissions, except for emission of CO from the synthetic fuel, which, at leaner conditions, was one-quarter of that measured for Jet Al. Detailed analysis of the organic compounds showed that the emissions from both fuels were dominated by fuel alkanes and a significant amount of naphthalene. It was also found that Jet Al produced a much higher amount of benzene than the synthetic fuel.
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| 3. |
- Owrang, Farshid, 1972, et al.
(författare)
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A method for in-situ quantification of oxygen in oil using fast neutron activation analysis
- 2004
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Ingår i: Kerntechnik. - 0932-3902. ; 69:1-2, s. 51-57
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Tidskriftsartikel (refereegranskat)abstract
- The feasibility of an experimental methodology for in-situ quantification of oxygen in bulk oil using fast neutron activation analysis (FNAA) has been studied. The method was applied for determination of oxygen in 100 ml (~90 g) rapeseed oil. The amount of oxygen in the rapeseed oil using the in-situ FNAA was estimated to 10.6 ± 2.6 weight %. Using cyclic fast neutron activation analysis (cFNAA), the amount of oxygen in the oil was determined in average 9.9 ± 0.4 weight %. Based on Monte Carlo calculations on water, the optimal radius and height of a cylindrical container where the activity is distributed through stirring of the water would be about 10 cm and 44 cm, respectively. These dimensions give a volume of about 14 liters, which is suitable for any type of oil. The accuracy in the in-situ FNAA can be increased by a more precise determination of oxygen in rapeseed oil in the beginning of a dynamic process using cFNAA or alternatively by a better background subtraction.
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| 4. |
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| 5. |
- Owrang, Farshid, 1972, et al.
(författare)
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Chemical analysis of combustion products from an engine power plant fuelled with natural gas
- 2004
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Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627.
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Konferensbidrag (refereegranskat)abstract
- Combustion products, exhaust emissions and engine exhaust deposits formed on thermocouples, positioned after the heat exchanger of an engine power plant, were analyzed chemically. The engine was a lean burn 18W28SG 50 Hz (Wärtsilä NSD, Trollhättan Sweden) fuelled with natural gas equipped with a catalyst (Süd-Chemie NMHC catalyst). The exhaust emissions were sampled using the off-line bottle-in-bag (BiB) method and were analyzed by gas chromatography/flame ionization (GC/FID). Heavier organic compounds and aldehydes were separately collected using adsorption cartridges. The combustion products measured in the emissions were mainly ethene, propene and formaldehyde indicating normal combustion of the fuel in the engine. Organics contained in the engine exhaust deposits were extracted using three different extraction methods: thermal desorption (TD), liquid extraction (LE) and super critical fluid extraction (SFE). The extracts were analyzed by GC/MS. The chemical composition of the deposits before and after TD and LE was characterized using solid-state 13C NMR. The amount of oxygen in the deposits was measured using cyclic fast neutron activation analysis (cFNAA). A substantial part of the deposits (77 weight %) consisted of extractable organics. The remaining part of the deposits consisted of a carbon structure rich in aromatics and aliphatics. The amount of oxygen in the deposits was about 17 weight %. As expected, the results demonstrated that the deposits originated from engine oil. This was shown clearly using GC/MS analysis of components desorbed or extracted from the deposits combined with NMR of deposits.
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| 6. |
- Owrang, Farshid, 1972
(författare)
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Chemistry of Combustion Products Investigation of Combustion Chamber Deposits Formed in a Gasoline Direct Injection Stratified Charge SI Engine
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this work was to characterize deposits formed in the combustion chambers of a gasoline direct injection stratified charge SI engine. The engine was run with several types of gasoline fuels and a special reference engine oil. The deposits were analyzed in several ways: thermal desorption (TD) and liquid extraction followed by gravimetric analysis, gas chromatography/mass spectrometry (GC/MS), cyclic fast neutron activation analysis (cFNAA), solid state 13C nuclear magnetic resonance (NMR) spectroscopy and solid state 1H inverse recovery NMR spectroscopy (measuring the spin-lattice relaxation constant, T1). Combustion chamber deposits consisted of a volatile and a solid part. TD followed by GC/MS showed that up to 50 weight % of the deposits consisted of the volatiles. The volatiles were dominated by higher n-alkanes originating from the engine oil and contained small amounts of aromatics from gasoline. The results of solid state 13C NMR showed that the solid part of the deposits contained a substantial amount of polyaromatics. T1, from solid state 1H inverse recovery NMR, of the aliphatics contained in the deposits was measured to be about 0.2 s. As a comparison, the T1 of the engine oil was measured to be 0.46 s. The results indicate, in agreement with TD and GC/MS, that deposits contain a liquid phase derived from engine oil components. Up to 30 weight % of the combustion chamber deposits consisted of oxygen. The oxygen in the deposits was bound to different types of carbon compounds as oxygenated aliphatics, carboxyls and carbonyls. The fuels used in this study did not significantly affect the oxygen content and the organic composition of the deposits. Two methods were developed to study the oxidation of the engine oils. First, soot produced by the oxidation of oils in a thermal reactor was analyzed. The results showed that the reference engine oil degraded via formation of oxidized aliphatics. Soot produced by the reference oil at 550 °C was similar to deposits with respect to organic chemical composition and oxygen content. Second, in situ measurement of the amount of oxygen in oil in a sample container was carried out using fast neutrons. The sample size can be in the volume range of a few hundred milliliters up to several liters. Monte Carlo calculations showed that the optimal radius and height of the sample container were about 10 cm and 44 cm, respectively. This method could be used for quantification of oxygen in oil during a slow oxidation process.
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| 7. |
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| 8. |
- Owrang, Farshid, 1972, et al.
(författare)
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Solid-state 1H NMR spin-lattice relaxation in combustion chamber deposits from a gasoline direct injection engine
- 2004
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Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627.
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Konferensbidrag (refereegranskat)abstract
- Combustion chamber deposits from a gasoline direct injection stratified charge SI engine were analyzed using solid-state1H inverse recovery NMR spectroscopy, before and after thermal desorption (TD). The engine was run with a typical European base fuel, containing 9.8% MTBE. Before TD, solid-state1H NMR showed two broad peaks representing aliphatics and aromatics. The results showed that T1 (the relaxation time) of the aliphatics was significantly longer than T1 of the aromatics in the deposits. Deposits taken from the piston bowl, with the lowest volatility content, showed the shortest T1. In comparison, piston squish and piston bowl deposits, with higher volatility content showed a longer T 1. After TD, T1 of the aliphatics was shorter than the corresponding T1 of the aromatics. A decreasing T1 of aliphatics may be used for following a transition from a liquid (engine oil), via a semi-solid deposit to a solid carbon backbone. This may give a rough measure of the engine oil content of the deposits. Copyright © 2004 SAE International.
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