Hydrocarbon Group Type Research Articles

Catalytic Selectivity and H-Transfer in the Hydroconversion of a Petroleum Residue Using Dispersed Catalysts

Hydroconversion of a deasphalted vacuum residue of a crude oil has been performed in the presence of various disposable, dispersed catalysts at low concentration (450 ppm of metal) under identical conditions : a plasma-prepared nickel-carbon catalyst, an oil-soluble molybdenum naphthenate, and a commercial nickel-molybdenum supported on alumina, in order to obtain some insight into their influence upon the mechanisms of hydrogen transfer, and to evaluate their selectivities toward the production of various hydrocarbon groups. For this last purpose, a quantitative, rapid and accurate method for hydrocarbon group type analysis (saturates ±0.5 wt %, alkylaromatics ±0.6 wt %, aromatics ±1.0 wt %, polars ±0.4 wt % and an uneluted asphaltenic group ±0.2 wt %) has been used, based on an improved system of thin-layer chromatography with flame ionization detection. The catalysts significantly affect the quantitative distribution of hydrocarbon groups without producing new chemical families. The total hydrogen consumption is only slightly increased in the presence of these kind of catalysts. However, a different distribution of the hydrogen is achieved depending on the catalyst. Molybdenum naphthenate exhibits the higher hydrogen incorporation to its derived distillates, which in turn present significantly higher number-average molecular weight and percentage of saturates than those obtained with the other catalysts. For every catalyst studied, the more the incorporation of hydrogen in the distillates, the less the production of coke and gas. Throughout this paper, the agreement between the data obtained from TLC-FID and hydrogen balance is evidenced and explained.

Quantitative Hydrocarbon Group Type Analysis of Petroleum Hydroconversion Products Using an Improved TLC-FID System

This work deals with the study of an improved thin-layer chromatographic-flame-ionization detection (TLC-FID) system (using the newer configuration of the detector, an automatic sample spotter, and a careful selection of the operating parameters) in the quantitative hydrocarbon group type analysis of a deasphalted heavy oil from petroleum and its derived hydrocracking products. The separation method proposed allows for the detection and quantitation of saturates, alkylaromatics, aromatics, polars, and an uneluted fraction. The repeatability of the experiments has always been better than that of the ASTM D2007 standard for each fraction. It is not affected by application volumes or concentration in the studied ranges. Results from the absolute calibration method and from a variety of the internal normalization procedures are comparable, although the latter is faster and allows a rapid determination of the linear range of the detector. Factors such as eluent development length or application spot size do not influence the FID response of our samples under the studied conditions. Likewise, the behavior of the detector is linear with mass in the range studied for each separated fraction.

NAPHTHALENE AND ITS PRECURSORS IN IOMEX

ABSTRACT Iomex, an aromatic rich concentrate from kerosene feedstock is a potential source for production of naphthalene which has a variety of industrial applications. Four analytical procedures were standardized for compositional study of iomex according to chemical class wise. Hydrocarbon group type separation ( saturates, mono-and diaromatics ) and quantitation was reported using column chromatography, gas chromatography, high performance liquid chromatography and mass spectrometry. Data generated by these techniques are in good agreement with each other. A diaromatic fraction containing naphthalene and its precursors was studied in detail by gas chromatography mass spectrometry (GC-MS). Capillary GC could resolve each and every component of the diaromatic fraction, whereas quantitation and characterization of 27 components were obtained by mass spectrometry.

APPLICATION OF HIGH PERFORMANCE LIQUID CHROMATOGRAPHY FOR HYDROCARBON GROUP TYPE ANALYSIS OF CRUDE OILS

ABSTRACT High performance liquid chromatography (HPLC) was applied to four commercial grade Saudi Arabian crude oils having API gravity in the range 28 to 38 for the determination of hydrocarbon group types namely asphaltenes, saturates, aromatics and polars. Each of these crude oils was separated into asphaltenes and maltenes using n-hexane as the precipitating solvent. The maltenes (n-hexane soluble) were fractionated into saturates, aromatics and polars fractions by n-hexane elution on a column packed with amino propylsilane chemically bonded to porous silica particles. The data obtained shows that the weight percent saturates increase whereas aromatics, polars and asphaltenes decrease from Arab Heavy to Arab Bern through Arab Medium and Arab Light crude oil. The results obtained from HPLC were in comparison with those obtained from ASTM method D2007. This method is easier, faster and offer good repeatability. This method can be applied to other crude oils.

Characterization of North Sea petroleum fractions: hydrocarbon group types, density and molecular weight

Les composes satures et aromatiques des fractions C 10 a C 19 ou C 29 de treize petroles bruts et condensats norvegiens sont separes par chromatographie en phase liquide et analyses par spectrometrie de masse et chromatographie en phase gazeuse. Des correlations entre la teneur en aromatiques et la densite sont developpes

Hydrocarbon group type analysis of petroleum products by high-performance liquid chromatography on organo-metallic donor/acceptor-bonded silica

The preparation of a new organosilver bonded phase is described. The capacity ratios of 24 polynuclear aromatic hydrocarbons were determined and showed a charge-transfer mechanism. The separation of olefins in several light petroleum products was resolved. The performance of the stationary phase in hydrocarbon group type analysis is discussed.

Paraffins, olefins, naphthenes and aromatics analysis of selected hydrocarbon distillates using on-line column switching high-performance liquid chromatography with dielectric constant detection

A novel analytical method is introduced that measures the volume fraction of paraffins, olefins, naphthenes, and aromatics (PONA) in hydrocarbon liquids having distillation endpoints (American Society for Testing and Materials, ASTM D 2887) of at least 300°C. The method uses on-line column switching high-performance liquid chromatography (HPLC) with dielectric constant detection (DCD), i.e., HPLC-DCD. A specially configured hydrocarbon group-type analyzer system is used. The PONA separations are achieved using an olefin-selective column, an unsaturate-selective column, three naphthene-selective columns, two six-port switching valves, and Envron 123 as the mobile phase. The HPLC-DCD system ensures a genuine uniformity of response (less than 2.5% relative standard deviation) independent of the carbon number distribution of the sample or the group type. Unity response factors are sufficient for accurate quantitation. On the basis of complex solutions of hydrocarbon standards, the accuracy for each structural group type is within 2% absolute. The chromatographic limit of detection of the present system for naphthenes is less than 4.0 vol.% ( ca. 40 μg), for a kerosene fuel containing a wide carbon number distribution of both mono- and di-cycloparaffins, and is approximately 1.0 vol.% ( ca. 10 μg) for olefins. Sample turnaround time is approximately one hour. The results of the PONA analysis scheme are compared to those of the standard fluorescent indicator adsorption (FIA) liquid displacement method (ASTM D 1319), an alternative to the FIA method developed in this laboratory using HPLC-DCD, and a mass spectrometric method (ASTM D 2789) on standard mixtures and real-world products. For determining total naphthenes and olefins in the gasolines and kerosenes selected for study, the HPLC-DCD system was superior.

Hydrocarbon Groups Type Analysis of Petroleum Products by HPLC on Specific Stationary Phases

Abstract The hydrocarbon group types analysis of a large number of petroleum products by HPLC equipped with columns of suitable selectivity is described. An effective approach to the factors influencing the specificity of the columns was developped and stationary phases were synthetised in fonction of the products to be separated. All new phases were characterized by elemental, 29Si and 13C NMR analyses. The potentialities of theses phases were illustrated by analysis of selected samples either of fundamental or of industrial interest.

Rapid determination of naphthenes in hydrocarbon distillates using on-line column switching high-performance liquid chromatography with dielectric constant detection

On-line column switching high-performance liquid chromatography (HPLC) with dielectric constant detection (DCD) can separate and accurately quantify the volume fraction of total cycloparaffins in gasolines and kerosenes having distillation endpoints (ASTM D 2887) of at least 300°C. The three hydrocarbon group-types reported are: acyclic paraffins, cycloparaffins, and unsaturates, i.e., aromatics plus olefins. The HPLC—DCD separations are achieved using an “unsaturate-selective” column, two “naphthenic-selective” columns, two six-port switching valves, and Freon 123 as the mobile phase. Incorporation of one or two additional naphthenic-selective columns could extend the range of samples that can be analyzed to include diesel fuels. The dielectric constant detector ensures a genuine uniformity of response [relative standard deviation < 2.5%] for each hydrocarbon group type independent of the carbon number distribution of the sample. Unity response factors are sufficient for accurate quantitation. On the basis of complex solutions of hydrocarbon standards, the accuracy for each structural group type is within two percent absolute. The chromatographic limit of detection for naphthenes is less than 4.0 vol. % ( ca.40 μg) for a kerosene fuel containing a wide carbon number distribution of both mono- and di-cycloparaffins. Sample turnaround time is approximately 40 min.

Hydrocarbon group type analyzer system for the rapid determination of saturates, olefins, and aromatics in hydrocarbon distillate products

A dielectric constant (DC) detector for high-performance liquid chromatography (HPLC) is the basis of a rapid and accurate hydrocarbon group type analysis. This novel method can determine saturates, olefins, and total aromatics in hydrocarbon liquids with distillation end points (ASTM D 2887) of at least 400 /sup 0/C. The HPLC separation is achieved by using a single, olefin-selective column, a backflush valve, and Freon 123 as the mobile phase. The DC detector ensures a genuine uniformity of response (less than 2.5% relative standard deviation) for each hydrocarbon group type independent of the carbon number distribution of the sample. Unity response factors are sufficient. On the basis of complex solutions of hydrocarbon standards, the accuracy for each structural group type is within 1% absolute. The chromatographic limit of detection is less than 0.5 vol % (800 ng) for the last eluting hydrocarbon group, i.e., the olefins.

Quantitative determination of hydrocarbons by structural group-type via high-performance liquid chromatography with dielectric constant detection

A dielectric constant (DC) detector for high-performance liquid chromatography (HPLC) is the basis of an accurate and versatile hydrocarbon group-type analysis. The method can determine saturates (+ olefins), alkylbenzenes, and polynuclear aromatics in hydrocarbon liquids boiling below 600/sup 0/C. The HPLC separation is achieved with three columns in series, i.e., two (2) 5-..mu..m Partisil PAC columns preceding a 10-..mu..m TENF column, and using n-butyl chloride as the mobile phase. A simple three-component standard mixture is all that is required to calibrate the method. The DC detector ensures a genuine uniformity of response (less than 2.5% relative standard deviation) for each hydrocarbon group type independent of the carbon-number distribution of the sample. On the basis of simple and complex hydrocarbon standard solutions, the accuracy for each structural group type is within 2% absolute with a chromatographic limit of detection of approximately 150 ng for a late eluting solute (biphenyl). 16 references, 4 figures, 7 tables.

Hydrocarbon Group-Type Analysis of Petroleum Distillates and Residua by High-Performance Liquid Chromatography (Part 1)

Hydrocarbon Group-Type Analysis of Petroleum Distillates and Residua by High-Performance Liquid Chromatography (Part 1)

Preparative hydrocarbon group type determination by automated medium pressure liquid chromatography

Preparative hydrocarbon group type determination by automated medium pressure liquid chromatography

Hydrocarbon Group Types in Gasoline-Range Materials by High Performance Liquid Chromatography

Hydrocarbon Group Types in Gasoline-Range Materials by High Performance Liquid Chromatography

Rapid Hydrocarbon Group-Type Analysis by High Performance Liquid Chromatography

We have developed a rapid high performance liquid chromatographic[HPLC] method to determine analytically hydrocarbon group types: saturates, aromatics, polar compounds, and n-hexane insolubles in liquid or solid hydrocarbons [natural or synthetic]. This basic method is applicable to total crude oils, gasolines, kerosenes, middle distillates, fuel oils, residuals, lubricating oils and synthetic crudes derived from coal liquids, shale oils and tar sands. Data are presented which include both calibration factors and the analyses of these materials.

Determination of hydrogen in titanium metal by hot extraction

The present work addresses the conversion of spent engine oil into reusable useful diesel like fuel via two stage pyrolysis. In the 1st stage pyrolysis, pre-baked clay was used as adsorbent in order to remove impurities and to get a clear distillate product. In the 2nd stage, the clear distillate fraction was further pyrolyzed using different amounts of natural magnetite (1–5 wt%). The catalyst was prepared in the laboratory, and characterized by scanning electron microscopy (SEM), energy dispersive x-ray (EDX), X-ray diffractometry (XRD), and surface area analysis. The yields of overall products, liquid, gas and solid residue as a function of catalyst concentration were investigated and 3 wt% catalyst (optimum) gave 97.09, 72.31, 24.77 and 2.91% yields, respectively. The liquid fraction obtained at the optimum catalyst concentration was further characterized by Fourier Transform Infra Red (FT-IR) and Gas Chromatrography–Mass Spectrometry (GC–MS) in order to determine its detailed composition in terms of hydrocarbon ranges, hydrocarbon group type’s distribution and individual hydrocarbons in comparison with the thermal run. The fuel properties of the derived liquid fraction were also investigated using ASTM/IP standard methods. The results showed that the natural magnetite exhibited good catalytic activity and selectivity towards formation of hydrocarbons having fuel value in conformity to the diesel fuel.