A fluorescence depolarization technique was used to determine the molecular size of asphaltene solubility fractions a petroleum resid asphaltene. The determined at different emission wavelengths for each fraction. For subfraction range found vary considerably. However, given wavelength, sizes subfractions are very similar, that is differ from other by population distributions same set molecules. variation among due constituent components. distribution estimated published LDMS results.

Thermal decomposition of C10−C14 n-alkanes was studied under near-critical and supercritical conditions. The primary products were C1−Cm-2 C2−Cm-1 1-alkenes, the secondary cis- trans-2-alkenes, n-Cm-1, n-Cm+1, Cm+2−C2m-2 normal branched alkanes, where m is number carbon atoms in reactant. relative yields dependent upon reaction Product distributions exhibited large pressure dependence region. observed product changes composition with conditions explained by a modified free radical mechanism.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPyrolytic degradation studies of a coal-derived and petroleum-derived aviation jet fuelChunshan Song, Semih Eser, Harold H. Schobert, Patrick G. HatcherCite this: Energy Fuels 1993, 7, 2, 234–243Publication Date (Print):March 1, 1993Publication History Published online1 May 2002Published inissue 1 March 1993https://pubs.acs.org/doi/10.1021/ef00038a013https://doi.org/10.1021/ef00038a013research-articleACS PublicationsRequest reuse permissionsArticle...

Kinetics of thermal decomposition C10−C14 n-alkanes and their mixtures was studied under near-critical supercritical conditions. Supercritical-phase can be represented well by an apparent first-order kinetics, even though the not a true process. A generalized expression developed to predict rate constants for C8−C16 at 425 °C. Pressure had significant effect on constant in region. This large pressure attributed changes density possibly elementary reactions with this Individual compounds...

Thermal stressing of a JP-8 fuel was carried out in an isothermal flow reactor using nickel, stainless steel (316 and 304), Silcosteel, glass-lined tubes at 500 °C wall temperature 34 atm (500 psig) for 5 h liquid rate 1 mL/min. Different length segments along the sample were analyzed to observe deposit distribution throughout test section. Temperature-programmed oxidation (TPO) analysis SEM examination stressed showed differences amount nature solid deposits obtained on different...

Mesophase development during the carbonization of needle coke feedstocks in delayed coking affects microstructural anisotropy (or graphitizability) resulting coke. Previous work has employed gas chromatography/mass spectrometry (GC/MS) to study relationships between molecular composition fluid catalytic cracking decant oil (FCC DO) and mesophase development. In this study, principal emphasis was placed on analyzing non-GC amenable fraction DO samples using a combination analytical...

Thermal decomposition of two jet fuel model compounds, Decalin and Tetralin, was studied under near-critical supercritical conditions. Under high-pressure conditions, the thermal both compounds dominated by isomerization reactions. This is different from results obtained low-pressure high-temperature conditions where cracking reactions (for Decalin) or dehydrogenation Tetralin) dominate. The major liquid products were spiro[4,5]decane, 1-butylcyclohexene, 1-methylcyclohexene,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of Critical Properties (Tc, Pc) Some Jet FuelsJian Yu and Semih EserCite this: Ind. Eng. Chem. Res. 1995, 34, 1, 404–409Publication Date (Print):January 1995Publication History Published online1 May 2002Published inissue 1 January 1995https://pubs.acs.org/doi/10.1021/ie00040a045https://doi.org/10.1021/ie00040a045research-articleACS PublicationsRequest reuse permissionsArticle Views791Altmetric-Citations52LEARN ABOUT THESE...

In the delayed coking process, actual feed to drum consists of a high-boiling fraction feedstock, fluid catalytic cracking decant oil (FCC-DO), and end liquid products produced by (recycle). As distinct from parent feed, molecular composition behavior samples (CF) are reported for first time in this paper. This study examines commercial pretreatment approach where feedstock fractionator column includes hydrotreated (HYD) vacuum tower bottom (VTB) oil. Samples two sets oils including...

Two decant oils with different sulfur contents and their vacuum distillation fractions were hydrotreated in a fixed-bed flow reactor to produce feed sufficiently low content for needle coke production. Products from hydrotreatment subsequently carbonized tubing bomb characterize the carbonaceous mesophase development seen resulting semicoke. Although purpose of is reduce content, hydrogenation aromatic compounds also takes place during treatment, thus increasing hydrogen consumption. Modest...

Carbon deposition from jet fuel on metal surfaces will create problems for the operation of future aircraft. Two samples (Jet A and JP-8) were heated in a glass-lined flow reactor presence nonmetal substrates placed path. The solid deposits collected examined using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) by temperature-programmed oxidation (TPO). nature amount carbonaceous thermal decomposition determined to be dependent substrate properties...

Thermal stressing of Jet-A was conducted in a flow reactor on iron- and nickel-based metal surfaces at fuel rate 1 mL/min for 5 h wall temperature 350 °C 3.5 MPa (500 psig) so that both liquid-phase autoxidation thermal decomposition products contribute to the formation carbonaceous deposits. The deposits produced were characterized by field emission scanning electron microscopy (FESEM) programmed oxidation (TPO). effect surface deposit increases following order: AISI316 < AISI 321 ≈ 304...

This study investigates the hydrodesulfurization (HDS) of fluidized catalytically cracked decant oils used as feedstock for needle coke production. Three oils, representing a high (4.0 wt %), medium (2.5 and low (0.9 %) sulfur content, were hydrotreated in fixed-bed flow reactor. Removing from larger ring systems is most effective way reducing because large aromatics are significant contributors to product obtained delayed coking. Two commercial catalysts with different pore size...

A flow reactor study was carried out to investigate the carbon deposition on nickel-, cobalt-, molybdenum-, and iron-based alloy foils during thermal stressing of a JP-8 fuel at 500 °C wall temperature 34 atm (500 psig), for 5 h rate 4 mL/min. Temperature-programmed oxidation (TPO) analysis SEM examination showed that amount nature carbonaceous deposits depend strongly chemical composition foil surface. The deposited metal decreased in order Inconel 600 > Havar Fecralloy Waspaloy Hastelloy-C...

Flow reactor experiments were conducted to study carbon deposit formation from decomposition of a jet fuel (JP-8) at 500 °C and psig for 5 h on the surface two superalloys, Inconel 600 X. The deposits collected superalloy surfaces characterized by temperature-programmed oxidation, size exclusion microscopy, energy-dispersive X-ray spectroscopy. Significantly lower deposition X compared that was attributed presence minor elemental components, such as Al, Ti, Nb, Ta in alloy.

Temperature-programmed oxidation (TPO) is used to determine the reactivity of carbonaceous deposits formed on different substrates via thermal stressing jet fuel samples. The multiple CO2 peaks in TPO profiles are attributed differences deposits, which related their structural characteristics. This study investigates whether relate characteristics during stressing, or if they result from chemical alterations original analysis. question important for understanding substrate effects carbon...

Thermal decomposition of n-butylbenzene and n-butylcyclohexane was studied under near-critical supercritical conditions in relation to future jet fuel thermal stability problems. The reactions can be explained by free-radical mechanisms, dominated side-chain cracking. major liquid products from were styrene toluene. Toluene the product far region while dominant low-pressure subcritical region. main 1-methylcyclohexene cyclohexane. a secondary which derived methylenecyclohexane. This...