High-Temperature Stabilizers for Jet Fuels and Similar Hydrocarbon Mixtures. 1. Comparative Studies of Hydrogen Donors

Yoon, Emily M.; Selvaraj, Leena; Chen, Song; Stallman, John B.; Coleman, Michael M.

doi:10.1021/ef950228l

Cited by 66 publications

(73 citation statements)

References 9 publications

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“…In general, radical formation can be stabilized by the aromatic ring of a molecule such as 1,2,4-trimethylbenzene, which enhances the stability of the molecule compared to alkanes [50]. For fuel conservation in the military aircraft sector, additives with high thermal stability show a similar radical stabilization [51][52][53]. Due to this enhanced stability of the C-C-bonding, dodecane is more reactive towards CPOX compared to 1,2,4-trimethylbenzene and is therefore consumed at a higher rate.…”

Section: Influence Of Aromatic and Sulfur Contentmentioning

confidence: 99%

“…With a slower rate in steam reforming, there will be a higher by-product concentration at the catalyst outlet as a lower amount of the remaining hydrocarbons including reactants and by-products are consumed. stability show a similar radical stabilization [51][52][53]. Due to this enhanced stability of the C-C-bonding, dodecane is more reactive towards CPOX compared to 1,2,4-trimethylbenzene and is therefore consumed at a higher rate.…”

Section: Influence Of Aromatic and Sulfur Contentmentioning

confidence: 99%

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Spatial Concentration Profiles for the Catalytic Partial Oxidation of Jet Fuel Surrogates in a Rh/Al2O3 Coated Monolith

et al. 2016

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Abstract:The catalytic partial oxidation (CPOX) of several hydrocarbon mixtures, containing n-dodecane (DD), 1,2,4-trimethylbenzene (TMB), and benzothiophene (BT) as a sulfur compound was studied over a Rh/Al 2 O 3 honeycomb catalyst. The in-situ sampling technique SpaciPro was used in this study to investigate the complex reaction system which consisted of total and partial oxidation, steam reforming, and the water gas shift reaction. The mixtures of 83 vol % DD, 17 vol % TMB with and without addition of the sulfur compound BT, as well as the pure hydrocarbons were studied at a molar C/O-ratio of 0.75. The spatially resolved concentration and temperature profiles inside a central channel of the catalyst revealed three reaction zones: an oxidation zone, an oxy-reforming zone, and a reforming zone. Hydrogen formation starts in the oxy-reforming zone, not directly at the catalyst inlet, contrary to methane CPOX on Rh. In the reforming zone, in which steam reforming is the predominant reaction, even small amounts of sulfur (10 mg S in 1 kg fuel) block active sites.

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Section: Influence Of Aromatic and Sulfur Contentmentioning

confidence: 99%

Section: Influence Of Aromatic and Sulfur Contentmentioning

confidence: 99%

Spatial Concentration Profiles for the Catalytic Partial Oxidation of Jet Fuel Surrogates in a Rh/Al2O3 Coated Monolith

et al. 2016

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“…It has a three dimensional structure with orthorhombic symmetry [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. These materials are characterized by a 1-dimensional channel system parallel to c-axis with elliptical 10-membered ring with pore dimension of 0.39 x 0.63 nm [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The magnesium substituted MAPO-11, which has the acidic version of AEL structure might exhibit shape-selective catalysis of methylation of naphthalene.…”

Section: Modification Of Zsm 5 Using Ironmentioning

confidence: 99%

“…The magnesium substituted MAPO-11, which has the acidic version of AEL structure might exhibit shape-selective catalysis of methylation of naphthalene. reduces the consumption of structure-directing agents, and involves minimization of waste disposal and reduction of reactor volume [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. The uniform crystals with smaller particle size and also improvement of catalytic activity can be obtained by this method .…”

Section: Modification Of Zsm 5 Using Ironmentioning

confidence: 99%

Refinery Integration of By-Products from Coal-Derived Jet Fuels

Clifford¹,

Boehman²,

Chen³

et al. 2008

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The final report summarizes the accomplishments toward project goals during length of the project. The goal of this project was to integrate coal into a refinery in order to produce coalbased jet fuel, with the major goal to examine the products other than jet fuel. These products are in the gasoline, diesel and fuel oil range and result from coal-based jet fuel production from an Air Force funded program.The main goal of Task 1 was the production of coal-based jet fuel and other products that would need to be utilized in other fuels or for non-fuel sources, using known refining technology. The gasoline, diesel fuel, and fuel oil were tested in other aspects of the project.Light cycle oil (LCO) and refined chemical oil (RCO) were blended, hydrotreated to removed sulfur, and hydrogenated, then fractionated in the original production of jet fuel. Two main approaches, taken during the project period, varied where the fractionation took place, in order to preserve the life of catalysts used, which includes 1) fractionation of the hydrotreated blend to remove sulfur and nitrogen, followed by a hydrogenation step of the lighter fraction, and 2) fractionation of the LCO and RCO before any hydrotreatment. Another aspect was to hydrotreat decant oil for testing of the delayed coker. The yield and quality of jet fuel and the quality of all fuels were better when hydrotreating the whole blend to remove sulfur and nitrogen and fractionating gasoline and jet fuel for further hydrogenation. When fractionating the RCO and LCO before any hydrotreatment, the yield of jet fuel and diesel fuel decreased, and the yield of the fuel oil increased and was a low quality.Task 2 involved assessment of the impact of refinery integration of JP-900 production on gasoline and diesel fuel. Fuel properties, ignition characteristics and engine combustion of model fuels and fuel samples from pilot-scale production runs were characterized. The model fuels used to represent the coal-based fuel streams were blended into full-boiling range fuels to simulate the mixing of fuel streams within the refinery to create potential "finished" fuels. The representative compounds of the coal-based gasoline were cyclohexane and methyl cyclohexane, and for the coal-base diesel fuel they were fluorine and phenanthrene. Both the octane number (ON) of the coal-based gasoline and the cetane number (CN) of the coal-based diesel were low, relative to commercial fuels (~60 ON for coal-based gasoline and ~ 20 CN for coal-based diesel fuel). Therefore, the allowable range of blending levels was studied where the blend would iv achieve acceptable performance. However, in both cases of the coal-based fuels, their ignition characteristics may make them ideal fuels for advanced combustion strategies where lower ON and CN are desirable. The ignition characteristics and reaction pathways were examined for these fuels in a modified octane rating engine used as a form of rapid compression machine and in an ignition quality tester (IQT). Methyl cyclohexane was observed to...

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“…Previous studies at Pennsylvania State University have demonstrated that during the pyrolytic degradation of coal-and petroleumderived jet fuels, hydrogen transfer form hydrogen-donors, such as those present in coal-derived JP-8C jet fuel, could play an important role in suppressing thermal solid formation [10,14]. In previous papers [15][16][17][18], it has been reported that the formation of carbonaceous materials in jet fuel can be retarded by hydrogen donors such as tetrahydronaphthalene (THN), tetrahydroquinoline (THQ), and tetrahydronaphthol (THNol); and aromatic alcohol-type molecules such as benzyl alcohol and benzenedimethanol. More recent work at Pennsylvania State University has shown that THNol (especially the 1,2,3,4-isomer) and THN as well as benzyl alcohol are effective hydrogen donors for capping aliphatic radicals formed at temperatures > 400 °C while being transformed into relatively stable products [19].…”

Section: Introductionmentioning

confidence: 99%