scholarly journals The Effects of Different Sulfur Compounds on Jet Fuel Oxidation and Deposition

1995 ◽  
Author(s):  
Robert E. Kauffman
Keyword(s):  
Jet Fuel ◽  
Sulfur Compounds ◽  
Oxidation Products ◽  
Jet Fuels ◽  
Acid Base ◽  
Deposition Mechanism ◽  
Fuel Oxidation ◽  
Basic Nitrogen ◽  
Elemental Analyses ◽  
Steel Surfaces

This paper presents research which supports a proposed fuel oxidation/deposition mechanism involving acid: base reactions between “oxidizable” sulfur compounds, “basic” nitrogen compounds, and oxygen containing polymers. The reported research presents experiments which study the effects of different sulfur compounds on the high temperature (160–220°C) oxidation products and deposition tendencies of jet fuel. Surface analyses incorporating elemental analyses and depth profiles of deposits formed on steel surfaces were performed to identify the species involved in the initial stages of deposition by jet fuels. Experiments to study the effects of acid neutralizing compounds on the deposition tendencies of jet fuels are also presented.

The Effects of Different Sulfur Compounds on Jet Fuel Oxidation and Deposition

1997 ◽  
Vol 119 (2) ◽  
pp. 322-327 ◽  
Author(s):  
R. E. Kauffman
Keyword(s):  
Jet Fuel ◽  
Sulfur Compounds ◽  
Oxidation Products ◽  
Jet Fuels ◽  
Deposition Mechanism ◽  
Fuel Oxidation ◽  
Depth Profiles ◽  
Basic Nitrogen ◽  
Elemental Analyses ◽  
Steel Surfaces

This paper presents research that supports a proposed fuel oxidation/deposition mechanism involving acid:base reactions between “oxidizable” sulfur compounds, “basic” nitrogen compounds, and oxygen-containing polymers. The reported research presents experiments that study the effects of different sulfur compounds on the high-temperature (160–220°C) oxidation products and deposition tendencies of jet fuel. Surface analyses incorporating elemental analyses and depth profiles of deposits formed on steel surfaces were performed to identify the species involved in the initial stages of deposition by jet fuels. Experiments to study the effects of acid neutralizing compounds on the deposition tendencies of jet fuels are also presented.

scholarly journals Aspects of Jet Fuel Oxidation

1997 ◽  
Author(s):  
Steven Zabarnick ◽  
Shawn D. Whitacre
Keyword(s):  
Oxidation Rate ◽  
Oxygen Sensor ◽  
Jet Fuel ◽  
Jet Fuels ◽  
Surface Deposition ◽  
Fuel Oxidation ◽  
Headspace Oxygen ◽  
Sensor Technique ◽  
Metal Deactivator ◽  
Alkylperoxy Radicals

A quartz crystal microbalance (QCM)/Parr bomb system with a headspace oxygen sensor is used to measure oxidation and deposition during thermal oxidative stressing of jet fuel. The advantages of the oxygen sensor technique in monitoring fuel oxidation is demonstrated. Simultaneous measurement of deposition using the QCM shows a strong correlation between oxidation and deposition in jet fuels. Studies performed over the temperature range 140 to 180°C show that surface deposition peaks at an intermediate temperature, while bulk deposition increases with temperature, in studies of jet fuel antioxidants, we find that rapid increases in oxidation rate occur upon consumption of the antioxidant. The antioxidant appears to be consumed by reaction with alkylperoxy radicals. In studies of metal deactivator (MDA) additives, we find that MDA is consumed during thermal stressing, and this consumption results in large increases in the oxidation rate of metal containing fuels. Mechanisms of MDA consumption are hypothesized.

Aspects of Jet Fuel Oxidation

1998 ◽  
Vol 120 (3) ◽  
pp. 519-525 ◽  
Author(s):  
S. Zabarnick ◽  
S. D. Whitacre
Keyword(s):  
Oxidation Rate ◽  
Oxygen Sensor ◽  
Jet Fuel ◽  
Jet Fuels ◽  
Surface Deposition ◽  
Fuel Oxidation ◽  
Headspace Oxygen ◽  
Sensor Technique ◽  
Metal Deactivator ◽  
Alkylperoxy Radicals

A quartz crystal microbalance (QCM)/Parr bomb system with a headspace oxygen sensor is used to measure oxidation and deposition during thermal oxidative stressing of jet fuel. The advantages of the oxygen sensor technique in monitoring fuel oxidation is demonstrated. Simultaneous measurement of deposition using the QCM shows a strong correlation between oxidation and deposition in jet fuels. Studies performed over the temperature range 140 to 180°C show that surface deposition peaks at an intermediate temperature, while bulk deposition increases with temperature. In studies of jet fuel antioxidants, we find that rapid increases in oxidation rate occur upon consumption of the antioxidant. The antioxidant appears to be consumed by reaction with alkylperoxy radicals. In studies of metal deactivator (MDA) additives, we find that MDA is consumed during thermal stressing, and this consumption results in large increases in the oxidation rate of metal containing fuels. Mechanisms of MDA consumption are hypothesized.

Ignition Characteristics of a Fischer-Tropsch Synthetic Jet Fuel

2008 ◽  
Author(s):  
P. Gokulakrishnan ◽  
M. S. Klassen ◽  
R. J. Roby
Keyword(s):  
Kinetic Model ◽  
Ignition Delay ◽  
Flow Reactor ◽  
Kinetic Mechanism ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Jet Fuels ◽  
Ignition Delay Times ◽  
Delay Times ◽  
Ignition Characteristics

Ignition delay times of a “real” synthetic jet fuel (S8) were measured using an atmospheric pressure flow reactor facility. Experiments were performed between 900 K and 1200 K at equivalence ratios from 0.5 to 1.5. Ignition delay time measurements were also performed with JP8 fuel for comparison. Liquid fuel was prevaporized to gaseous form in a preheated nitrogen environment before mixing with air in the premixing section, located at the entrance to the test section of the flow reactor. The experimental data show shorter ignition delay times for S8 fuel than for JP8 due to the absence of aromatic components in S8 fuel. However, the ignition delay time measurements indicate higher overall activation energy for S8 fuel than for JP8. A detailed surrogate kinetic model for S8 was developed by validating against the ignition delay times obtained in the present work. The chemical composition of S8 used in the experiments consisted of 99.7 vol% paraffins of which approximately 80 vol% was iso-paraffins and 20% n-paraffins. The detailed kinetic mechanism developed in the current work included n-decane and iso-octane as the surrogate components to model ignition characteristics of synthetic jet fuels. The detailed surrogate kinetic model has approximately 700 species and 2000 reactions. This kinetic mechanism represents a five-component surrogate mixture to model generic kerosene-type jets fuels, namely, n-decane (for n-paraffins), iso-octane (for iso-paraffins), n-propylcyclohexane (for naphthenes), n-propylbenzene (for aromatics) and decene (for olefins). The sensitivity of iso-paraffins on jet fuel ignition delay times was investigated using the detailed kinetic model. The amount of iso-paraffins present in the jet fuel has little effect on the ignition delay times in the high temperature oxidation regime. However, the presence of iso-paraffins in synthetic jet fuels can increase the ignition delay times by two orders of magnitude in the negative temperature (NTC) region between 700 K and 900 K, typical gas turbine conditions. This feature can have a favorable impact on preventing flashback caused by the premature autoignition of liquid fuels in lean premixed prevaporized (LPP) combustion systems.

Characterization of Fuel Composition and Altitude Impact on Gaseous and Particle Emissions From a Turbojet Engine

2017 ◽  
Author(s):  
Tak W. Chan ◽  
Pervez Canteenwalla ◽  
Wajid A. Chishty
Keyword(s):  
Co2 Emissions ◽  
Nox Reduction ◽  
Cetane Number ◽  
Combustion Efficiency ◽  
Jet Fuel ◽  
Jet Fuels ◽  
Fuel Composition ◽  
Worst Case ◽  
Particle Emissions ◽  
Turbojet Engine

The effects of altitude and fuel composition on gaseous and particle emissions from a turbojet engine were investigated as part of the National Jet Fuels Combustion Program (NJFCP) effort. Two conventional petroleum based jet fuels (a “nominal” and a “worst-case” jet fuel) and two test fuels with unique characteristics were selected for this study. The “worst-case” conventional jet fuel with high flash point and viscosity resulted in reduced combustion efficiency supported by the reduced CO2 emissions and corresponding increased CO and THC emissions. In addition, increased particle number (PN), particle mass (PM), and black carbon (BC) emissions were observed. Operating the engine on a bimodal fuel, composed of heavily branched C12 and C16 iso-paraffinic hydrocarbons with an extremely low cetane number did not significantly impact the engine performance or gaseous emissions but significantly reduced PN, PM, and BC emissions when compared to other fuels. The higher aromatic content and lower hydrogen content in the C-5 fuel were observed to increase PN, PM, and BC emissions. It is also evident that the type of aromatic hydrocarbons has a large impact on BC emissions. Reduction in combustion efficiency resulted in reduced CO2 emissions and increased CO and THC emissions from this engine with increasing altitudes. PN emissions were moderately influenced by altitude but PM and BC emissions were significantly reduced with increasing altitude. The reduced BC emissions with increasing altitude could be a result of reduced combustion temperature which lowered the rate of pyrolysis for BC formation, which is supported by the NOx reduction trend.

scholarly journals Production Cost and Carbon Footprint of Biomass-Derived Dimethylcyclooctane as a High Performance Jet Fuel Blendstock

2021 ◽  
Author(s):  
Nawa Raj Baral ◽  
Minliang Yang ◽  
Benjamin G. Harvey ◽  
Blake A Simmons ◽  
Aindrila Mukhopadhyay ◽  
...  
Keyword(s):  
Production Cost ◽  
High Performance ◽  
Jet Fuel ◽  
Liquid Fuels ◽  
Jet Fuels ◽  
Selling Price ◽  
Low Carbon ◽  
Hydrogenation Catalysts ◽  
Raney Nickel Catalyst ◽  
Biomass Sorghum

<div> <div> <div> <p>Near-term decarbonization of aviation requires energy-dense, renewable liquid fuels. Biomass- derived 1,4-dimethylcyclooctane (DMCO), a cyclic alkane with a volumetric net heat of combustion up to 9.2% higher than Jet-A, has the potential to serve as a low-carbon, high- performance jet fuel blendstock that may enable paraffinic bio-jet fuels to operate without aromatic compounds. DMCO can be produced from bio-derived isoprenol (3-methyl-3-buten-1- ol) through a multi-step upgrading process. This study presents detailed process configurations for DMCO production to estimate the minimum selling price and life-cycle greenhouse gas (GHG) footprint considering three different hydrogenation catalysts and two bioconversion pathways. The platinum-based catalyst offers the lowest production cost and GHG footprint of $9.0/L-Jet-Aeq and 61.4 gCO2e/MJ, given the current state of technology. However, when the conversion process is optimized, hydrogenation with a Raney nickel catalyst is preferable, resulting in a $1.5/L-Jet-Aeq cost and 18.3 gCO2e/MJ GHG footprint if biomass sorghum is the feedstock. This price point requires dramatic improvements, including 28 metric-ton/ha sorghum yield and 95-98% of the theoretical maximum conversion of biomass-to-sugars, sugars-to-isoprenol, isoprenol-to-isoprene, and isoprene-to-DMCO. Because increased gravimetric energy density of jet fuels translates to reduced aircraft weight, DMCO also has the potential to improve aircraft efficiency, particularly on long-haul flights. </p> </div> </div> </div>

Impact of deep hydrogenation on jet fuel oxidation and deposition

Fuel ◽  
2020 ◽  
Vol 264 ◽  
pp. 116843 ◽  
Author(s):  
Tinghao Jia ◽  
Si Gong ◽  
Lun Pan ◽  
Chuan Deng ◽  
Ji-Jun Zou ◽  
...  
Keyword(s):  
Jet Fuel ◽  
Fuel Oxidation

Experimental and Modeling Study of the Combustion of Synthetic Jet Fuels: Naphtenic Cut and Blend With a GtL Jet Fuel

2016 ◽  
Author(s):  
Philippe Dagaut ◽  
Pascal Diévart
Keyword(s):  
Air Transportation ◽  
Chemical Kinetic ◽  
Jet Fuel ◽  
Synthetic Jet ◽  
Sensitivity Analyses ◽  
Jet Fuels ◽  
Kinetic Reaction ◽  
Experimental Database ◽  
Initial Fuel ◽  
Kinetics Of

Research on the production and combustion of synthetic jet fuels has recently gained importance because of their potential for addressing security of supply and sustainable air transportation challenges. The combustion of a 100% naphtenic cut that fits with typical chemical composition of products coming from biomass or coal liquefaction (C12.64H23.64; M=175.32 g.mol−1; H/C=1.87; DCN=39; density=863.1 g.L−1) and a 50% vol. mixture with Gas to Liquid from Shell (mixture: C11.54H23.35; M=161.83 g.mol−1; H/C=2.02; DCN=46; density=800.3 g.L−1) were studied in a jetstirred reactor under the same conditions (temperature, 550–1150 K; pressure, 10 bar; equivalence ratio, 0.5, 1, and 2; initial fuel concentration, 1000 ppm). Surrogate model-fuels were designed based on fuel composition and properties for simulating the kinetics of oxidation of these fuels. We used new model-fuels consisting of mixtures of n-decane, decalin, tetralin, 2-methylheptane, 3-methylheptane, n-propyl cyclohexane, and n-propylbenzene. The detailed chemical kinetic reaction mechanism proposed was validated using the entire experimental database obtained in the present work and for the oxidation of pure GtL, we used previous results. Kinetic computations involving reaction paths analyses and sensitivity analyses were used to interpret the results.

Use Differential Pulse Voltammetry for Determining the 2,6-Ditertbutyl-4-Methylphenol in Jet Fuels

2012 ◽  
Vol 455-456 ◽  
pp. 716-720 ◽  
Author(s):  
Yong Gang Shi ◽  
Bin Su ◽  
Hai Feng Gong ◽  
Yan Xue
Keyword(s):  
Differential Pulse Voltammetry ◽  
Standard Addition ◽  
Differential Pulse ◽  
Jet Fuel ◽  
Jet Fuels ◽  
Addition Method ◽  
Electrolytic Solution ◽  
Voltammetric Characteristics ◽  
Pulse Voltammetry

A new method for determination of antioxidants in jet fuels, which is based on the differential pulse voltammetric characteristics of the antioxidant 2,6-ditertbutyl-4-methylphenol in the solution of saturated KOH anhydrous ethyl alcohols, is established. The experimental results have shown that there is a linear relationship between the content of 2,6-ditertbutyl-4-Methyl-phenol in the jet fuel and the differential pulse voltammetry response in the electrolytic solution. It has also been shown that the antioxidant contents can be reliably and simply determined with the help of the standard addition method. The largest relative error of the determination is 6.70 %, the biggest confidence for 5 samples is 1.95 mg/L (n=5, 95% confidence level).

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