摘要:

In the conventional Hot Water Extraction Process bitumen is separated as a froth that is then diluted with naphtha and subjected to two stages of centrifugation. The resulting bitumen solution still contains residual water, dissolved salts and mineral solids. Before upgrading the solvent and other volatile components are removed by topping at 524°C. The salts and mineral solids remain with topped bitumen; their presence can lead to serious operational problems in the bitumen upgrading process. In the present work the solids associated with bitumen (BS) have been identified as mainly ultra-fine (nano sized) aluminosilicate clays coated with strongly bound toluene insoluble organic material having “asphaitene characteristics”. It is proposed that these ultra-fine clays with their strong tendency to collect at oil-water interfaces, are the key component responsible for the presence of intractable water and associated salts in bitumen froth.

ISSN:1091-6466    

DOI:10.1080/10916469808949769

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The distribution patterns of methylhomologs of naphthalene and phenanthrene in five crude oils from the southern part of the Gulf of Suez, Egypt, have been examined by quantitative capillary gas chromatography (GC) and computerized gas chromatography/mass spectrometry (GC/MS). In general, the relative abundance of individual naphthalenes and phenanthrenes were not significantly different in the five oil samples. Correlation between the source rock deposition and the abundance of specific methylnaphthalene and melhylphenanthrene isomers are consistent with a marine type source materials for the analyzed Gulf of Suez oils. Maturity parameters based on methylnaphthalene and methylphenanthrene isomers were almost identical and are consistent with an advanced stage of maturity. Further, calculated vitrinite reflectance (Re) confirmed that the sediments have a range of maturity within the “oil window”.

ISSN:1091-6466    

DOI:10.1080/10916469808949770

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The hydration of butene-1 over H-mordenite and H-mordenite composited with different amounts of zeolite-β has been investigated in a batch reactor. The products of the reaction were sec-butanol (SBA), diisobutylether (DIBE) and C8-oligmer. The reaction was carried out over H-mordenite at different operational conditions of a reaction temperature and built-up pressure. The maximum activity (46% of the thermodynamic equilibrium) of H-mordenhe was observed at 250°C and 180.27 atm with 88% selectivity of SBA and no formation of C« dimmer by-product. The structural characteristics of a H-form of the composited catalysts, containing 10, 15 and 45 wt% of zeolite-β, were studied by means of an electron dispersion system (EDS) technique in order to determine SiO2/Al2O3ratio and % degree of exchange. It was found that SiO2/Al2O3ratio ranges between 20.2 and 29.61 indicating that all the catalysts could be considered as siliceous zeolites. The acidic properties of the pure mordenites and those composited with zeolite-β were determined potentiometrically in an aqueous medium. From the results obtained, it is obvious that the catalysts, containing mordenite composited with 15 and 45 wt% of zeolite-β, possess stronger acidic -OH's than pure mordenites. Also, the hydration activity of zeolites seemed to be strongly correlated with their protonic acid strength. The activity and selectivity of the composited zeolites for the hydration reaction were studied at the optimum operational conditions and compared with those of pure mordenite. The binary composited zeolites, containing 15 and 45 wt% of zeolite-β were found to be more active and selective for the hydration of butene -1 than those of pure mordenite. It was suggested that the activity and selectivity of the binary zeolite catalyst system may be due to shape selectivity of β-zeolite, high surface acidity and hydrophobic nature exhibited by the two forms of zeolites.

ISSN:1091-6466    

DOI:10.1080/10916469808949771

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

In the present paper attempts have been made to study the phase transition temperatures in petroleum waxes by infrared spectroscopy and the resulting data were correlated with phase transition temperatures obtained by differential scanning calorimetry (DSC).

ISSN:1091-6466    

DOI:10.1080/10916469808949772

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The neat asphalt samples collected from the different asphalt producing refineries in the Gulf countries were subjected to two aging processes to simulate heating, mixing and compaction, and in service aging. The asphalt samples of the different aging stages were subjected to physical and chemical tests. The measured physical and consistency properties were used to calculate various temperature susceptibility indices. Corbett analysis, Ion exchange chromatography, HP-GPC, and FT-1R analysis were used to study the effect of aging on the molecular nature of asphalts.

ISSN:1091-6466    

DOI:10.1080/10916469808949773

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Moisture-induced damage in petroleum asphalt pavements, which results in a loss of pavement tensile strength, is a significant contributor to pavement performance problems such as rutting, shoving, flushing and cracking. Results of the present study provide fundamental information on some of the chemistries of moisture-induced damage. Model compounds containing polar chemical functional group types found in asphalts were used to simulate the adsorption-water displacement characteristics of asphalt molecules on mineral aggregate surfaces. A comparative and interpretative discussion of the model compound studies and earlier studies on actual asphalt-aggregate mixtures is presented. Carboxylic acids were confirmed as the functional type most strongly adsorbed on most mineral aggregate surfaces; however, they were also the functional type most easily water displaced. Pyridine-type functionality similar to that found in asphalts reduced the sensitivity of asphalt-aggregate mixtures to moisture damage. Results suggest that prior treatment of aggregates with antistripping agents rather than their prior addition to the asphalts should improve the moisture resistance of mixtures. The reaction of carboxylic acids with aggregate surfaces prior to the reaction of the aggregate surfaces with pyridine-type functionality greatly increased the sensitivity of the pyridine types to displacement by water. Also, the reaction of pyridine with carboxylic acid functionalities prior to their adsorption on aggregate surfaces also increased their sensitivity to water displacement. Results of the model compound studies provided further interpretation of the results of earlier fundamental studies on the adsorption and water displacement characteristics of actual asphalt components from aggregates typically used in paving mixtures. Results are interpreted with regard to their usefulness in finding pragmatic solutions to pavement pavement moisture damage problems. Further needed research is also suggested.

ISSN:1091-6466    

DOI:10.1080/10916469808949774

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The amount of paraffins influences the quality of petroleum products by change of physical properties as they are ductility, adhesion, cold resistance, temperature dependence of viscosity, and brittleness as well as processing behavior of bitumen. We present a method based on extraction with entrainer modified supercritical carbondioxid for quantitative separation of paraffins from heavy petroleum products. Limitations of the method were determined by use of model mixtures such as macrocrystalline, microcrystalline and pure straight chain Fischer-Tropsch wax representing different kinds of paraffins. The method prooved to be well suited for all samples under investigation. Identification of the extracted paraffins was performed by thin layer chromatography with flame ionization detection and by high temperature gas chromatography.

ISSN:1091-6466    

DOI:10.1080/10916469808949775

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Lubricating oil base stocks differ greatly in their chemical composition and consequently in their physical properties and applications. Influence of waxes and various hydrocarbon type constituents viz saturates and aromatic components on the viscosity and shear stress as a function of temperature in different lube oil base stocks has been studied in the present paper.

ISSN:1091-6466    

DOI:10.1080/10916469808949776

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Studies in the literature have reported correlations of Microcarbon Residue (MCR) either with hydrogen to carbon atomic ratio (H/C) or with the number average molecular weight (Mn). The MCR value can be an indication of die coke yield in a commercial coking process. In this work a single correlation of MCR widi both H/C and Mnhas been presented. Vacuum residue distillation fractions from hydroprocessing experiments were separated into five sub-fractions by preparative scale gel permeation chromatography, and characterized in terms of H/C, M„and MCR. In accordance with other correlations it was confirmed that increasing the H/C atomic ratio will decrease coke formation (MCR)- In addition this work has shown that for identical H/C ratio, molecules with smaller Mnvalues will produce less coke than those with larger Mn; values.

ISSN:1091-6466    

DOI:10.1080/10916469808949777

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

This study was conducted to compare the percentage of olefins in cracked naphthas determined by PONA, with that calculated from Bromine Number, according to ASTM D 1159-93 method. Olefins calculated from Bromine Number were comparable to those determined by PONA, except for cracked naphtha fractions in which aromatics are in large proportion. Furthermore, it was demonstrated that Bromine Number can be used to estimate the olefins/aromatics ratio.

ISSN:1091-6466    

DOI:10.1080/10916469808949778

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor