Jet fuel

This review discusses the problems of sulfur reduction in highway and non-road fuels and presents an overview of new approaches and emerging technologies for ultra-deep desulfurization of refinery streams for ultra-clean (ultra-low-sulfur) gasoline, diesel fuels and jet fuels. The issues of gasoline and diesel deep desulfurization are becoming more serious because the crude oils refined in the US are getting higher in sulfur contents and heavier in density, while the regulated sulfur limits are becoming lower and lower. Current gasoline desulfurization problem is dominated by the issues of sulfur removal from FCC naphtha, which contributes about 35% of gasoline pool but over 90% of sulfur in gasoline. Deep reduction of gasoline sulfur (from 330 to 30 ppm) must be made without decreasing octane number or losing gasoline yield. The problem is complicated by the high olefins contents of FCC naphtha which contributes to octane number enhancement but can be saturated under HDS conditions. Deep reduction of diesel sulfur (from 500 to <15 ppm sulfur) is dictated largely by 4,6-dimethyldibenzothiophene, which represents the least reactive sulfur compounds that have substitutions on both 4-and 6-positions. The deep HDS problem of diesel streams is exacerbated by the inhibiting effects of co-existing polyaromatics and nitrogen compounds in the feed as well as H 2 S in the product. The approaches to deep desulfurization include catalysts and process developments for hydrodesulfurization (HDS), and adsorbents or reagents and methods for non-HDS-type processing schemes. The needs for dearomatization of diesel and jet fuels are also discussed along with some approaches. Overall, new and more effective approaches and continuing catalysis and processing research are needed for producing affordable ultra-clean (ultra-low-sulfur and low-aromatics) transportation fuels and non-road fuels, because meeting the new government sulfur regulations in 2006-2010 (15 ppm sulfur in highway diesel fuels by 2006 and non-road diesel fuels by 2010; 30 ppm sulfur in gasoline by 2006) is only a milestone. Desulfurization research should also take into consideration of the fuel-cell fuel processing needs, which will have a more stringent requirement on desulfurization (e.g., <1 ppm sulfur) than IC engines. The society at large is stepping on the road to zero sulfur fuel, so researchers should begin with the end in mind and try to develop long-term solutions.

Sustainable non-food energy biomass and cost-effective ways to produce renewable energy technologies from this biomass are continuously emerging. Algae are capable of producing lipids and hydrocarbons quickly and their photosynthetic abilities make them a promising candidate for an alternative energy source. In addition, their favorable carbon life cycle and a renewed focus on rural economic development are attractive factors. In this review the focus is mainly on the integrated approach of algae culture for bioremediation and oil-based biofuel production with mention of possible other value-added benefits of using algae for those purposes.

Hydrogen is a very promising alternative fuel for road transport sector in order to reduce emissions of carbon dioxide and other pollutants which are increasingly affecting the health of the planet and citizens. Certainly, it is believed that the simplest employment of hydrogen is as a fuel into internal combustion engines (ICEs) due to the enormous experience that ICEs technology has gained in the last century. However, hydrogen properties determine some drawbacks when used in ICEs. These  drawbacks can be overcome by using the direct-injection strategy. Therefore, a comprehensive study of hydrogen jets is needed both to evaluate the feasibility of such engines and to provide guidance for the development of new strategies in order to improve their performance
and efficiency.
This work examines fundamental problems related to the fluid dynamic structure of turbulent compressible hydrogen jets by using High Performance Computing (HPC) methodologies.
The first aim is to untangle the question whether it is necessary to include the real gas assumption dealing with hydrogen jets. The answer to this question is needed in order to guarantee accurate numerical simulations of such jets in practical engineering applications, such as direct-injection hydrogen engines. An axial symmetric turbulent flow model, which solves the Favre-averaged Navier-Stokes equations for a multicomponent
gas mixture, has been implemented and validated. The flow model has been assessed by comparing spreading and centerline property decay rates of subsonic jets at different Mach numbers with those obtained by both theoretical considerations and experimental measurements. Besides, the Mach disk structure of underexpanded jets has been recov-
ered, thus confirming the suitability and reliability of the computational model. To take into account the effects of real gases, both van der Waals and Redlich-Kwong equations of state have been implemented. The analysis of highly underexpanded hydrogen jets with three different values of total pressure, i.e. 75 MPa, 50 MPa and 25 MPa, issuing
into nitrogen at 5 MPa, shows that the use of real gas equations of state affects significantly the jet structure in terms of temperature, pressure and Mach number profiles along the jet centerline and also in terms of jet exit conditions, with differences up to 38 %.
Dealing with hydrogen jets another fundamental issue is to understand if the high density ratio that characterizes such jets affects the mixing properties in terms of spreading rate. This concern has been investigated by using a Large Eddy Simulation (LES) model which uses a sixth-order compact finite difference scheme to discretize the governing equations
and a very recent Localized Artificial Diffusivity (LAD) scheme in order to remove the numerical instabilities that are not dumped by the high-order non-dissipative numerical scheme. The simulations of a subsonic hydrogen jet, at Mach number 0.8, have shown that the model is able to correctly predict the velocity decay rate. Moreover they have shown that the spreading rate is strongly affected by the density ratio and is less
influenced by the compressibility effects.

On the quest for reducing the fuel consumption per passenger per flight for economical and environmental reasons, commercial aircraft manufacturers are implementing new strategies for optimising aircraft performance by using new lighter and stronger materials and enhancing engines' efficiencies in terms of fuel consumption and maintenance requirements. With the rising and falling of economies, whether in the Organization for Economic Cooperation and Development (OECD) countries or other developing countries, the aviation industry has been affected by multiple factors such as passenger traffic, freight traffic, airport capacities and oil prices. Aircraft manufacturers have worked on improving the engine efficiency of their newly built airplanes (e.g. Airbus's A-380 and Boeing's B-787), and many airports in the world have increased the number of their runways to face the increasing demand for air traffic in the world. Aviation efficiency can also be achieved through better load management, which in return enables airliners to cope with higher oil prices or rising costs. Aviation fuel demand is modelled in OECD North America, Europe and Pacific regions and some selected developing countries. Price elasticities of fuel demand in all regions are low, while income elasticities are high. The elasticity of aviation fuel demand on passenger kilometre performed (PKP) is considerably low. One per cent increase in PKP leads to less than half a per cent increase in aviation fuel demand, confirming an ongoing fuel efficiency in aviation industry.

Corresponding author sarathy1@llnl.gov 925.423.6011 Conventional petroleum jet and diesel fuels, as well as alternative Fischer-Tropsch (FT) fuels and hydrotreated renewable jet (HRJ) fuels, contain high molecular weight lightly branched alkanes (i.e., methylalkanes) and straight chain alkanes (n-alkanes). Improving the combustion of these fuels in practical applications requires a fundamental understanding of large hydrocarbon combustion chemistry.

The major concern with aspects of sustainability, particularly the reduction of environmental impacts, have opened the way for a new market of fuels, including aviation fuel. Air transport accounts for 2% of annual carbon emissions caused by man. In 2009, the aviation industry within the International Civil Aviation Organization (ICAO), signed the reduction commitment carbon emissions as a way to reduce that share of contribution, based on three objectives: 1) improving fuel efficiency on average by 1.5% per year by 2020; 2) Level the net emissions through a carbon neutral growth from 2020; and 3) cut net emissions in half by 2050 compared to 2005 (IATA, 2015). To reach the ambitious goals, it has been created several initiatives to develop the sector and leverage the use of Aviation Biokerosene as the Brazilian initiative "Brazilian Alliance for Aviation Biofuels (ABRABA)," European "European Advanced Biofuels Flight Path"; American "Commercial Aviation Alternative Fuels Initiative (CAAFI)"; and the International “Initiative Sustainable Aviation Fuel Users Group (SAFUG)”. In this line, this paper aims to present and compare these global initiatives with Brazil in order to discern possible suggestions for improvements to the Brazilian case. All evaluated initiatives seek to generally promote sustainable development of the production and use of aviation biofuels chain, reducing emissions of gases causing the greenhouse effect, but there are peculiarities in initiatives that deserve attention and that can be harnessed to the case Brazilian in order to position it as a true global player in the development of the sector. It is suggested to set specific goals for production and use of aviation biofuels, such as the European Advanced Biofuels Flight Path. Promote study group to assess the sustainability of aviation fuel, considering it is also for the the indirect effect of land use changes in English Indirect Land Use Change (ILUC), like the group of sustainable fuel users, Sustainable Aviation Fuel Users Group (SAFUG). Seek the effective participation of government officials, decision makers, the initiatives, similar to what is done in the Commercial Aviation Alternative Fuels Initiative (CAAFI). Thus, the aviation bio-kerosene use in Brazil and the world can contribute essential way to achieve the sustainability goals set by ICAO.

An experimental study is conducted for the laminar, atmospheric pressure, sooting, coflow diffusion flames of prevaporized Jet A-1 and four synthetic jet fuels to compare their sooting characteristics and flame structures. Soot volume fraction, species concentration, and temperature profiles are measured, using the laser extinction measurement method, gas chromatography, and fine wire thermocouples, respectively. To evaluate the sooting tendency of the fuels, their smoke point heights are measured using the ASTM D1322 method and compared. The synthetic jet fuels under investigation are (1) Fully Synthetic Jet Fuel (FSJF), which is a coal-to-liquids (CtL) kerosene plus some coal tar derived material from Sasol, (2) FischerÀTropsch Synthetic Paraffinic Kerosene (FT-SPK), which is a gas-to-liquids (GtL) product from Shell, (3) SPK plus naphthenic cut (50% by volume), and (4) SPK plus hexanol (20% by volume). The threshold sooting index (TSI) of the proposed surrogate mixtures for the fuels are calculated and compared to the TSI of the real fuels to evaluate the performance of the surrogates in predicting the sooting behavior of the actual fuels. The surrogate mixtures underpredict the sooting tendency of the Jet A-1, FSJF, and SPK + naphthenic cut, although they correctly capture the trend. It is shown that the soot concentration and the TSI values are strongly dependent on the aromatic content of the fuels. Fuels with the largest soot concentrations and sooting indexes, in decreasing order, are Jet A-1, FSJF, SPK + naphthenic cut, FT-SPK, and SPK + hexanol. There are minor differences between the species concentration and temperature profiles of the heavily sooting flames (Jet A-1, FSJF, and SPK + naphthenic cut) and the lightly sooting flames (FT-SPK and SPK + hexanol), caused by the lower contribution of aromatics to the formation of light aliphatic species and the higher radiative heat transfer by soot particles in the heavily sooting flames. It is demonstrated that the soot levels in flames are proportional to benzene concentrations but not to acetylene levels. Thus, only aromatic-based inception models can capture the differences in soot formation for jet fuels.

A turbulent lifted slot-jet flame is studied using direct numerical simulation (DNS). A one-step chemistry model is employed with a mixture-fraction dependent activation energy which can reproduce qualitatively the dependence of laminar burning rate on equivalence ratio that is typical of hydrocarbon fuels. The basic structure of the flame base is first examined and discussed in the context of earlier experimental studies of lifted flame. Several features previously observed in experiments are noted and clarified. Some other unobserved features are also noted. Comparison with previous DNS modelling hydrogen flames reveals significant structural differences. The statistics of flow and relative edge-flame propagation velocity components conditioned on the leading edge locations are then examined. The results show that on average, the streamwise flame propagation and streamwise flow balance, thus demonstrating that edge-flame propagation is the basic stabilisation mechanism. Fluctuations of the edge locations and net edge velocities are, however, significant. It is demonstrated that the edges tend to move in an essentially two-dimensional elliptical pattern (laterally outwards towards the oxidiser, then upstream, then inwards towards the fuel, then downstream again). It is proposed that this is due to the passage of large eddies, as outlined in Su et al. (2006). However, the mechanism is not entirely two-dimensional, and out-of-plane motion is needed to explain how flames escape the high velocity inner region of the jet. Finally, the time-averaged structure is examined. A budget of terms in the transport equation for product mass fraction is used to understand the stabilisation from a time-averaged perspective. The result of this analysis is found to be consistent with the instantaneous perspective. The budget revealed a fundamentally two-dimensional structure , involving transport both in streamwise and transverse directions, as opposed to possible mechanisms involving a dominance of either one direction of transport. It featured upstream transport balanced by entrainment into richer conditions, while on the rich side, upstream turbulent transport and entrainment from leaner conditions balances the streamwise convection.

Considering liquid fuels from a variety of feedstocks and refinement processes, evaporating sprays of various fuels are investigated in a constant-volume chamber at ambient and injection conditions typical of a diesel engine. For diesel sprays, the liquid phase of the spray reaches a maximum penetration distance soon after the start of injection, while the vapor phase of the spray continues to penetrate downstream. This liquid-phase penetration distance or in short, the ''liquid length'', depends upon the ambient and fuel-injector conditions. To clarify fuel effects on liquid length and vapor penetration, in this study we performed simultaneous high-speed imaging of Mie-scattering and schlieren at approximately 50-kHz framing rates. Experiments were performed at specified ambient gas temperature and density in an environment with 0% oxygen. This non-reacting condition was selected intentionally to isolate the mixing and vaporization processes from more complex effects of combustion. Fuels with a wide range of boiling points and densities were examined, including a conventional No. 2 diesel, low-aromatics jet fuel, worldaverage jet fuel, Fischer-Tropsch synthetic fuel, coal-derived fuel, and a two-component surrogate fuel. Results show that the liquid length increases with increasing fuel density for fuels of similar boiling-point temperature. Considering a mixing-limited vaporization process, entrained ambient mass per fuel mass is inversely proportional to the fuel density, and thereby, high fuel density causes a decrease in ambientto-fuel ratio, which increases liquid length. Consequently, both boiling point and density of fuel affect liquid length. In contrast to the liquid-length result, no correlation between fuel density and vapor penetration was found. This is because the momentum flux, which governs the jet penetration, is not a function of the fuel density. Although the liquid length varies, the similarity in vapor penetration for all fuels investigated shows that the fuel density and boiling point do not significantly affect the total entrainment and mixing into the spray.

In order to further reduce the sulfur content in liquid hydrocarbon fuels (gasoline, diesel fuel and jet fuel) for producing ultra-clean transportation fuels and for fuel cell applications, we explored a new desulfurization process by selective adsorption for removing sulfur (SARS). An adsorbent was developed and used for adsorption desulfurization of diesel fuel, gasoline and jet fuel at room temperature. The results indicate that the transition metal-based adsorbent developed in this work is effective for selectively adsorbing the sulfur compounds, even the refractory sulfur compounds in diesel fuels. The SARS process can effectively remove sulfur compounds in the liquid hydrocarbon fuels at ambient temperature under atmospheric pressure with low investment and operating cost. On the basis of the present study, a novel integrated process is proposed for deep desulfurization of the liquid hydrocarbon fuels in a future refinery, which combines a selective adsorption (SARS) of the sulfur compounds and a hydrodesulfurization process of the concentrated sulfur fraction (HDSCS). The SARS concept may be used for on-site or on-board removal of sulfur from fuels for fuel cell systems.

単純だが包括的にジェットの幅広い種類のダイナミクスを記述する二相流体モデルを提案する。基本的な仮定は①ジェットは軸対称であり、②動的平衡にある液体と気体の混合状態として近似することができる。質量と運動量流束を全体的または部分的な保存のいずれかを課すことによって、4つのモデルを導出し、解析解・半解析解そして数値解を求めた。主な結果は、ノズルからの軸方向距離の関数として、二相流体の混合平均密度及び速度を予測することが出来、そこから動圧が計算出来る。また、文献に広く用いられている平衡速度係数の実験式を理論的に導出する。各モデルの結果を比較し、その予測は実験データとよく比較することを示す。
　液体ジェットは産業応用が多様で盛んに用いられている。例えば、スプレー、燃料噴射、水カッター等はもちろん、医療や環境問題でも活躍する。二相流体を構成する霧化液体ジェットの応用範囲は非常に大きい。しかしながら、噴霧プロセスの複雑さ、多数の物理現象と多くの変数を含む噴霧過程、ジェットが飛ぶ環境との相互作用とノズル内の状態（またはある他の発生源）に至るまで、数多くの物理現象の数学的モデリングの課題として残されている。いくつかの数学的モデルは、この領域でジェットのさまざまな側面を記述するためにたてられた。我々の知る限り、従来のモデルは、液体・気体混合ジェットの平均密度やスプレーの動的な圧力などの物理量を説明できない。

Low-temperature fuel cells offer the potential for long mission duration when coupled to a highenergy-density fuel in an auxiliary fuel tank. Candidate high-energy-density fuels include methanol, diesel, and jet fuels. However, all of these fuels must be reformed into hydrogen which is subsequently consumed by the fuel cell to generate electrical power. Thus, a fuel processor becomes a necessary component in the overall fuel cell system.

Fires are important responsible factors to cause catastrophic events in the process industries, whose consequences usually initiate domino effects. The artificial neural network has been shown to be one of the rapid methods to simulate processes in the risk analysis field. In the present work, experimental data points on jet fire shape ratios, defined by the 800 K isotherm, have been applied for ANN development. The mass flow rates and the nozzle diameters of these jet flames have been considered as input dataset; while, the jet flame lengths and widths have been collected as output dataset by the ANN models. A Bayesian Regularization algorithm has been chosen as the three-layer backpropagation training from Multi-layer perceptron algorithm. Then it has been compared with a Radial based functions algorithm, based on single hidden layer. The optimized number of neurons in the first and second hidden layers of the MLP algorithm, and in the single hidden layer of the RBF algorithm has been found to be twenty and fifteen, respectively. The best MSE validation performance of MLP and RBF networks has been found to be 0.00286 and 0.00426 at 100 and 20 epochs, respectively.

In this paper we test for the most effective cross hedging instrument for the Singapore spot market in jet fuel over the period February 4, 1997 to August 21, 2001. Our results are mixed. We find that the heating oil contract is the best in-sample cross-hedging instrument. It has the ...

The global combustion characteristics of 2,6,10-trimethyl dodecane (trimethyl dodecane), a synthetic fuel candidate species, have been experimentally investigated by measuring extinction limits for strained laminar diffusion flames at 1 atm and reflected shock ignition delays at 20 atm. The Derived Cetane Number (DCN) of trimethyl dodecane, (59.1) and Hydrogen/Carbon (H/C) ratio (2.133) are very close to the DCN and H/C ratio of a previously studied synthetic aviation fuel, S-8 POSF 4734 (S-8) and its surrogate mixture composed of n-dodecane/iso-octane (58.9 and 2.19, respectively). Identical high temperature global kinetic reactivities are observed in all experiments involving the aforementioned compounds. However, at temperatures below $870 K, the S-8 surrogate mixture has ignition delay times approximately a factor of two faster. A chemical functional group analysis identifies that the methylene (CH 2 ) to methyl (CH 3 ) ratio globally correlates the low temperature alkylperoxy radical reactivity for these large paraffinic fuels. This result is further supported experimentally, by comparing observations using a surrogate fuel mixture of n-hexadecane (n-cetane) and 2,2,4,4,6,8,8-heptamethyl nonane (iso-cetane) that shares the same methylene-to-methyl ratio as trimethyl dodecane, in addition to the same DCN and H/C ratio. Measurements of both diffusion flame extinction and reflected shock ignition delays show that the n-cetane/iso-cetane model fuel has very similar combustion behavior to trimethyl dodecane at all conditions studied. A kinetic modeling analysis on the model fuel suggests the formation of alkylhydroperoxy radicals (QOOH) to be strongly influenced by the absence or presence of the methyl and methylene functional groups in the fuel chemical structure. The experimental observations and analyses suggest that paraffinic based fuels having high DCN values may be more appropriately emulated by further including the CH 2 to CH 3 ratio as an additional combustion property target, as DCN alone fails to fully distinguish the relative reaction characteristics of low temperature kinetic phenomena.

Fires are important responsible factors to cause catastrophic events in the process industries, whose consequences usually initiate domino effects. The artificial neural network has been shown to be one of the rapid methods to simulate processes in the risk analysis field. In the present work, experimental data points on jet fire shape ratios, defined by the 800 K isotherm, have been applied for ANN development. The mass flow rates and the nozzle diameters of these jet flames have been considered as input dataset; while, the jet flame lengths and widths have been collected as output dataset by the ANN models. A Bayesian Regularization algorithm has been chosen as the three-layer backpropagation training from Multi-layer perceptron algorithm. Then it has been compared with a Radial based functions algorithm, based on single hidden layer. The optimized number of neurons in the first and second hidden layers of the MLP algorithm, and in the single hidden layer of the RBF algorithm has been found to be twenty and fifteen, respectively. The best MSE validation performance of MLP and RBF networks has been found to be 0.00286 and 0.00426 at 100 and 20 epochs, respectively.

Leakage of jet fuel from an oil skimmer has resulted in soil and groundwater contamination at the fire fighting training site of the Oslo international airport. The site is located on an unconfined sandy aquifer formed by the Gardermoen ice contact delta. A strong relationship between hydrogeological settings and spatial distribution of the hydrocarbons has been observed. Leaching hydrocarbons constitute a source of dissolved BTEX and naphthalene. Concentration of the dissolved hydrocarbons, electron acceptors and metabolic by-products has revealed concomitant changes in space and in time, in response to groundwater fluctuations. Correlation between high concentrations of hydrocarbons, elevated alkalinity and depleted electron acceptors supports the hypothesis that intrinsic bioremediation has been taking place at the site. Naphthalene, however, has been found persistent under anoxic conditions. Calculations of biodegradation potential indicates that Fe(III) reduction, methanogenesis, nitrate and sulphate reduction are the main factors controlling biodegradation.

In recent years, civilian and military users of aviation kerosene have been interested in expanding the scope of fuel feed stocks to include nonpetroleum sources. There are many reasons for this, the most important of which are the potential minimization of supply disruptions, the minimization of dependence on foreign sources of petroleum, the vulnerability of large centralized refineries, and the rising costs of current fuel streams. It is unlikely that a completely new, drop-in replacement fuel will be successful in the foreseeable future. In the meantime, however, the goal is to extend or enhance present petroleum-derived stocks. For this to be done on a rational basis, careful attention must be paid to fuel design parameters, one of the most important of which is the fluid volatility as expressed by the distillation curve. We have recently introduced several important improvements in the measurement of distillation curves of complex fluids. The modifications to the classical measurement provide for (1) a composition explicit data channel for each distillate fraction (for both qualitative and quantitative analysis); (2) temperature measurements that are true thermodynamic state points that can be modeled with an equation of state; (3) temperature, volume, and pressure measurements of low uncertainty suitable for equation of state development; (4) consistency with a century of historical data; (5) an assessment of the energy content of each distillate fraction; (6) trace chemical analysis of each distillate fraction; and (7) a corrosivity assessment of each distillate fraction. The composition explicit channel is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to the measurement of rocket propellant, gasolines, jet fuels, and hydrocarbon crude oils. In this paper, we present the application of the technique to compare the characteristics of several new synthetic isoparaffinic kerosenes that are being used or tested as turbine fuels. These fuels include synthetics made from natural gas, coal, and waste greases. . (1) Muzzell, P. S. L.; Freerks, R.; McKay, B.; Terry, A.; Sattler, E. Properties of Fischer-Tropsch (FT) blends for use in military equipment. Kinder, J D.; Henry, M.; Crenfeldt, G.; LeDuc, G. F.; Zombanakis, G. P.; Abe, Y.; Lambert, D. M.; Lewis, C.; Juenger, J. A.; Andac, M. G.; Reilly, K. R.; Holmgren, J.; McCall, M. J.; Bozzano, A. G. Sustainable bio-derived synthetic paraffinic kerosene (bio-SPK) jet fuel flight tests and engine program results. In 9th AIAA

Fuel composition can have a significant effect on soot formation during gas turbine combustion. Consequently, this paper contains a comprehensive review of the relationship between fuel hydrocarbon composition and soot formation in gas turbine combustors. Two levels of correlation are identified. First, lumped fuel composition parameters such as hydrogen content and smoke point, which are conventionally used to represent fuel sooting tendency, are correlated with soot formation in practical combustors. Second, detailed fuel hydrocarbon composition is correlated with these lumped parameters. The two-level correlation makes it possible to predict soot formation in practical combustors from basic fuel composition data. Threshold sooting index (TSI), which correlates linearly with the ratio of fuel molecular weight and smoke point in a diffusion flame, is proposed as a new lumped parameter for sooting tendency correlation. It is found that the TSI model correlates excellently with hydrocarbon compositions over a wide range of fuel samples. Also, in predicting soot formation in actual combustors, the TSI model produces the best results overall in comparison with other previously reported correlating parameters, including hydrogen content, smoke point, and composite predictors containing more than one parameter.

We analyzed protein expression in preparations from whole testis in adult male Sprague-Dawley rats exposed for 6 h/d for 91 consecutive days to jet propulsion fuel-8 (JP-8) in the vapor phase (0, 250, 500, or 1000 mg/m3 ± 10%), simulating a range of possible human occupational exposures. Whole body inhalation exposures were carefully controlled to eliminate aerosol phase, and subjects were sacrificed within 48 h postexposure. Organ fractions were solubilized and separated via large-scale, high resolution two-dimensional electrophoresis, and gel patterns scanned, digitized and processed for statistical analysis. Seventy-six different testis proteins were significantly increased or decreased in abundance in vapor-exposed groups, compared to controls, and dose-response profiles were often nonlinear. A number of the proteins were identified by peptide mass fingerprinting and related to histopathological or physiological deficits shown in previously published studies to occur with repeated exposure to hydrocarbon fuels or solvents. These results demonstrate a significant effect of JP-8 exposure on protein expression, particularly in protein expression in the rodent testis, and suggest that a 91 d exposure to jet fuel vapor induces changes of equal or greater magnitude to those reported previously for shorter duration JP-8 aerosol exposures.

VULCAN Series Xc 300 - Jet Fuel Treating Technology
CONTENTS
Introduction – VULCAN Series Xc 300
Process Benefits
Catalyst Benefits
Catalyst Properties
Principal Applications

Kerosene Sweetening
Chemistry
Process Requirements
Bender History
Lead Health Hazard Information

Process Objectives
Process Improvement Summary
GBHE Commercial Experience

In this paper we report a novel four-step process for the production of jet and diesel fuel range alkanes from hemicellulose extracts derived from northeastern hardwood trees. The extract is representative of a byproduct that could be produced by wood-processing industries such as biomass boilers or pulp mills in the northeastern U.S. The hemicellulose extract tested in this study contained mainly xylose oligomers (21.2 g/l xylose after the acid hydrolysis) as well as 0.31 g/l glucose, 0.91 g/l arabinose, 0.2 g/l lactic acid, 2.39 g/l acetic acid, 0.31 g/l formic acid, and other minor products. The first step in this process is an acid-catalyzed biphasic dehydration to produce furfural in yields up to 87%. The furfural is extracted from the aqueous solution into a tetrahydrofuran (THF) phase which is then fed into an aldol condensation step. The furfural-acetone-furfural (F-Ac-F) dimer is produced in this step by reaction of furfural with acetone in yields up to 96% for the F-Ac-F dimer. The F-Ac-F dimer is then subject to a low-temperature hydrogenation to form the hydrogenated dimer (H-FAF) at 110-130 • C and 800 psig with a 5 wt% Ru/C catalyst. Finally the H-FAF undergoes hydrodeoxygenation to make jet and diesel fuel range alkanes, primarily C 13 and C 12 , in yields up to 91%. The theoretical yield for this process is 0.61 kg of alkane per kg of dry xylose derived from the hemicellulose extract. Experimentally we were able to obtain 76% of the theoretical yield for the overall process. We estimate that jet and diesel fuel range alkanes can be produced from between $2.06/gal to $4.39/gal depending on the feed xylose concentration, the size of the biorefinery, and the overall yield. Sensitivity analysis shows that the prices of raw materials, the organic-to-aqueous mass ratio in the biphasic dehydration, and the feed xylose concentration in the hemicellulose extract significantly affect the product cost.

Operational and commercial efficiency at a jet fuel depot are vital indices for a jet fuel marketer toward ensuring maximum business productivity. In Nigeria, jet A-1 aviation fuel scarcity is a yearly challenge that periodically triggers jet fuel price increase, air fare price hike and flight cancellation. The causes of the scarcity have been ascribed to the challenges facing jet fuel supply process. In this study, the significance of each of the seven jet fuel depots of a fuel marketer to the overall business performance is analysed using structural equation modelling to evaluate the historical sales and stock data. Historical stock data contain hidden patterns and knowledge that can be acquired and applied in operational decision-making processes. The effect of each depot on business performance is classified using the significance and path coefficient result obtained from the partial least squares model implemented on historical stock data. The analysis reveals the significance of adequate stock level via supply chain management, and this creates an opportunity for directing management policies and decisions at less significant depots based on the data-mined knowledge acquired. An overall model R 2 value of 0.902 was achieved. This study emphasises the relevance of quality data even in the aviation fuel industry.

In this work, we investigate the utility of the smoke lamp for evaluating the soot-reducing potential of additives, by comparing it to a more complex liquid-fed laminar diffusion flame. The additives, ferrocene (bis(cyclopentadienyl) iron-Fe(C 5 H 5 ) 2 ), ruthenocene (bis(cyclopentadienyl)ruthenium-Ru(C 5 H 5 ) 2 ), iron naphthenate (a 12% iron salt of naphthenic acid, which is a mixture of fatty carboxylic acids, some of which may include a cyclopentane ring), and MMT (Methylcyclopentadienyl manganese tricarbonyl-CH 3 C 5 H 4 Mn(CO) 3 ) are evaluated at various concentrations in the jet fuel JP-8. Although the smoke lamp is a simple, inexpensive, and widely-available test for evaluating the sooting potential of liquid fuels, it does not provide an effective measure of soot suppression by metal-containing additives. The drop-tube reactor more accurately captures the physical conditions and processes-droplet vaporization, ignition, and rich vs. lean operation-typically found in more complex systems. We find in the smoke lamp that ferrocene, and to a lesser degree ruthenocene, are effective soot suppressors when used in JP-8, and that their effectiveness increases with increasing concentration. In the smoke lamp, MMT and iron naphthenate have minimal effect. On the other hand, in the drop-tube reactor, all four additives are quite effective, especially at fuel lean conditions, where soot suppression reaches 90-95%. Under fuel-rich conditions, where in some cases the additives elevate the yield of soot aerosol slightly, we find a significant increase in the production of the soluble organic fraction of the aerosol, i.e., tar. In order to understand why the smoke lamp sometimes fails to indicate a soot suppressing potential (i.e., from MMT and iron naphthenate), soot samples were collected from a wick lamp burning ferrocene and iron naphthenate additives in JP-8. These samples, as well as several from the drop-tube reactor, were analyzed by X-Ray Fluorescence (XRF) in order to determine their metal content, and we find that the soot aerosol produced by the wick lamp using ferrocene-containing fuel had roughly 30 times the iron content of the soot aerosol produced by the wick lamp using iron-naphthenatecontaining fuel. This difference in metal content is not found in samples produced in the drop-tube reactor. We conclude that the poor performance of iron naphthenate in the smoke lamp is likely the result poor vaporization of the additive from the wick, a consequence of its high molecular weight (average 465).

We report on the transient and persistent effects of JP-8 jet fuel exposure on auditory function in rats. JP-8 has become the standard jet fuel utilized in the United States and North Atlantic Treaty Organization countries for military use and it is closely related to Jet A fuel, which is used in U.S. domestic aviation. Rats received JP-8 fuel (1000 mg/m 3 ) by nose-only inhalation for 4 h and half of them were immediately subjected to an octave band of noise ranging between 97 and 105 dB in different experiments. The noise by itself produces a small, but permanent auditory impairment. The current permissible exposure level for JP-8 is 350 mg/m 3 . Additionally, a positive control group received only noise exposure, and a fourth group consisted of untreated control subjects. Exposures occurred either on 1 day or repeatedly on 5 successive days. Impairments in auditory function were assessed using distortion product otoacoustic emissions and compound action potential testing. In other rats, tissues were harvested following JP-8 exposure for assessment of hydrocarbon levels or glutathione (GSH) levels. A single JP-8 exposure by itself at 1000 mg/m 3 did not disrupt auditory function. However, exposure to JP-8 and noise produced an additive disruption in outer hair cell function. Repeated 5-day JP-8 exposure at 1000 mg/m 3 for 4 h produced impairment of outer hair cell function that was most evident at the first postexposure assessment time. Partial though not complete recovery was observed over a 4-week postexposure period. The adverse effects of repeated JP-8 exposures on auditory function were inconsistent, but combined treatment with JP-8 + noise yielded greater impairment of auditory function, and hair cell loss than did noise by itself. Qualitative comparison of outer hair cell loss suggests an increase in outer hair cell death among rats treated with JP-8 + noise for 5 days as compared to noise alone. In most instances, hydrocarbon constituents of the fuel were largely eliminated in all tissues by 1-h postexposure with the exception of fat. Finally, JP-8 exposure did result in a significant depletion of total GSH that was observable in liver with a nonsignificant trend toward depletion in the brain and lung raising the possibility that the promotion of noise-induced hearing loss by JP-8 might have resulted from oxidative stress.

In the present study, experiments as well as numerical computations based on finite volume method have been carried out to investigate the entrainment of ambient air into a laboratory-scale louvred funnel, which are mostly used in naval warships and cargo ships to suppress infrared emissions. Conservation equations for mass, momentum and energy are solved in a three-dimensional domain by employing eddy viscosity based two equation k − ε turbulence model with log-law wall functions. Reynolds number, louvred opening area as well as nozzle protruding length are varied in the range of 3250 ≤R e ≤ 6600, 116.7 ≤ A L /D 2 nz ≤ 584, and 0 < L p /D nz < 12, respectively. It is observed that the mass suction increases with the Reynolds number, louvred opening area and nozzle protruding length. The louvred openingarea is the most important parameter in the entrainment process and then, the nozzle protruding length is the second most affecting parameter on air suction. Experiments using hot nozzle fluid are conducted to establish the fact that hotter fluid will always entrain more surrounding air compared to the cold nozzle fluid because of buoyancy. It is also observed that the computed and experimental values of mass entrainment rates agree well with each other.

A common problem associated with subsurface contamination is the leaking of light nonaqueous phase liquids (LNAPLs) such as gasoline from underground storage tanks and other facilities. A model developed by Corapcioglu et al. (1996) to describe LNAPL transport on the water table was solved numerically, by accounting for residual NAPL retained by capillary forces. The model was exercised to simulate LNAPL mound formation and migration of an established mound. The results show that the ambient groundwater velocity has major effects on both the formation and migration of LNAPL mounds, although the degree of residual saturation affected only migration. Model results provide distributions of the NAPL phase and contaminated soil. The model and the solution method developed in this study can be used as a screening tool to assess the impact of NAPL contamination and to estimate remediation costs.

Conventional petroleum jet and diesel fuels, as well as alternative Fischer-Tropsch (FT) fuels and hydrotreated renewable jet (HRJ) fuels, contain high molecular weight lightly branched alkanes (i.e., methylalkanes) and straight chain alkanes (n-alkanes). Improving the combustion of these fuels in practical applications requires a fundamental understanding of large hydrocarbon combustion chemistry. This research project presents a detailed and reduced chemical kinetic mechanism for singly methylated iso-alkanes (i.e., 2-methylalkanes) ranging from C 8 to C 20. The mechanism also includes an updated version of our previously published C 8 to C 16 n-alkanes model. The complete detailed mechanism contains approximately 7,200 species 31,400 reactions. The proposed model is validated against new experimental data from a variety of fundamental combustion devices including premixed and nonpremixed flames, perfectly stirred reactors and shock tubes. This new model is used to show how the presence of a methyl branch affects important combustion properties such as laminar flame propagation, ignition, and species formation.

We report on the transient and persistent effects of JP-8 jet fuel exposure on auditory function in rats. JP-8 has become the standard jet fuel utilized in the United States and North Atlantic Treaty Organization countries for military use and it is closely related to Jet A fuel, which is used in U.S. domestic aviation. Rats received JP-8 fuel (1000 mg/m 3 ) by nose-only inhalation for 4 h and half of them were immediately subjected to an octave band of noise ranging between 97 and 105 dB in different experiments. The noise by itself produces a small, but permanent auditory impairment. The current permissible exposure level for JP-8 is 350 mg/m 3 . Additionally, a positive control group received only noise exposure, and a fourth group consisted of untreated control subjects. Exposures occurred either on 1 day or repeatedly on 5 successive days. Impairments in auditory function were assessed using distortion product otoacoustic emissions and compound action potential testing. In other rats, tissues were harvested following JP-8 exposure for assessment of hydrocarbon levels or glutathione (GSH) levels. A single JP-8 exposure by itself at 1000 mg/m 3 did not disrupt auditory function. However, exposure to JP-8 and noise produced an additive disruption in outer hair cell function. Repeated 5-day JP-8 exposure at 1000 mg/m 3 for 4 h produced impairment of outer hair cell function that was most evident at the first postexposure assessment time. Partial though not complete recovery was observed over a 4-week postexposure period. The adverse effects of repeated JP-8 exposures on auditory function were inconsistent, but combined treatment with JP-8 + noise yielded greater impairment of auditory function, and hair cell loss than did noise by itself. Qualitative comparison of outer hair cell loss suggests an increase in outer hair cell death among rats treated with JP-8 + noise for 5 days as compared to noise alone. In most instances, hydrocarbon constituents of the fuel were largely eliminated in all tissues by 1-h postexposure with the exception of fat. Finally, JP-8 exposure did result in a significant depletion of total GSH that was observable in liver with a nonsignificant trend toward depletion in the brain and lung raising the possibility that the promotion of noise-induced hearing loss by JP-8 might have resulted from oxidative stress.

Laminar flame speeds of practical fuels including Jet-A1, diesel, palm methyl esters (PME) and blends of PME with diesel and Jet-A1 fuels are determined using the jet-wall stagnation flame configuration and particle imaging velocimetry (PIV) technique. The PME/Jet-A1 and PME/diesel blends are prepared by mixing 10%, 20% and 50% of PME with Jet-A1 and diesel fuels by volume respectively. The experiments are performed over a range of stoichiometries at elevated temperature of 470 K and atmospheric pressure under premixed conditions. The reference flame speed and imposed strain rates are determined from the two dimensional velocity profiles. Subsequently, laminar flame speeds are derived by extrapolating the reference flame speed back to zero strain rates. Experimental results are compared to experimental and simulation data from the literature for large n-alkanes and practical fuels. The results show that laminar flame speeds of Jet-A1 fuel are similar to those of n-decane and n-dodecane, indicating their potential use as surrogate fuels. Peak laminar flame speeds for diesel/air and PME/air mixtures at 470 K are similar, around 86.7 and 86.5 cm/s at equivalence ratios around 1.10 and 1.14 respectively, and that both mixtures exhibit lower flame speeds compared to n-decane and n-dodecane at fuel-leaner and stoichiometric conditions. Blending PME with Jet-A1 and diesel leads to reduced laminar flame speeds on the lean side but increased on the rich side.

This study was designed to characterize and compare the pulmonary effects in distal lung from a low-level exposure to jet propellant-8 fuel (JP-8) and a new synthetic-8 fuel (S-8). It is hypothesized that both fuels have different airway epithelial deposition and responses. ...

No current studies have systematically examined pulmonary health effects associated with Syntroleum S-8 synthetic jet fuel (S-8). In order to gain an understanding about the threshold concentration in which lung injury is observed, C57BL/6 male mice were nose-only exposed to S-8 for 1 h/day for 7 days at average concentrations of 0 (control), 93, 352, and 616 mg/m 3. Evaluation of pulmonary function, airway epithelial barrier integrity, and pathohistology was performed 24 h after the final exposures. Significant decreases were detected in expiratory lung resistance and total lung compliance of the 352 mg/m 3 group, for which no clear concentration-dependent alterations could be determined. No significant changes in respiratory permeability were exhibited, indicating that there was no loss of epithelial barrier integrity following S-8 exposure. However, morphological examination and morphometric analysis of distal lung tissue, by using transmission electron microscopy, revealed cellular damage in alveolar type II epithelial cells, with significant increases in volume density of lamellar bodies/vacuoles at 352 and 616 S-8 mg/ m 3. Moreover, terminal bronchiolar Clara injury, as evidenced by apical membrane blebs, was observed at relatively low concentrations, suggesting if this synthetic jet fuel is utilized, the current permissible exposure limit of 350 mg/m 3 for hydrocarbon fuels should cautiously be applied.