Hydrocarbon Group Composition Research Articles

Calibration of GC-FID and IR Spectrometric Methods for Determination of High Boiling Petroleum Hydrocarbons in Environmental Samples

Calibration problems connected with the determination of C20-C44 petroleum hydrocarbons by gas chromatography – flame ionization detection (GC-FID) and IR spectrometric methods were studied in this paper. It has been found that the mass responses and mass response factors of FID determined by capillary GC-FID as well as by IR spectrometry, at wave number 2959 and 2924 cm-1, of high boiling petroleum distillation fractions (in the range C20-C46) are not constant. Moreover, it was found that mass response factors for differentpetroleum oils that have the same boiling temperature interval might differ up to 1.5 fold both for FID and IRD methods, dependingon their hydrocarbon group composition. However, calibration of the IR spectrometric method using the empirical equations proposed in DIN 38 409, Part 18, norm (for the determination of total petroleumhydrocarbons in waters polluted with high boiled petroleum fractions)gave results which overlapped within ±10% of the expected values.

Thermodiffusion separation of hydrogenated mineral oil

Hydrogenated mineral oil was separated in steady-state conditions and in a solvent stream by thermodiffusion. In thermodiffusion separation, isoparaffins are concentrated at the top of the tower and naphthenes are concentrated at the bottom. Solvent stream separation ensures more efficient separation of alkanes from naphthenes: fractions with a higher content of isoalkanes than in separation in steady-state conditions are obtained at the top of the tower. The dependence of the viscosity-temperature properties of thermodiffusion fractions of hydrogenated mineral oil on their group hydrocarbon composition is investigated.

Effect of surfactants on colloidal structure of lube distillates

The use of NMR makes it possible to register fine effects at the micro level due to changes, caused by the presence of the surfactant, in the diffusional mobility of the molecules of disperse phase and dispersion medium in the lube fraction. Additional information on the influence of surfactants on the colloidal structure of lube fractions can be obtained by dielectric spectroscopy, since these fractions are dielectrics. In our work, the molecules of the oil fractions and their associates were subjected to polarization with subsequent reorientation under the influence of an ac electric field. The 350-420~ lube distillate that we investigated had been obtained from a 1:2 mixture of Tuimazy and West Siberian crudes. The physicochemical characteristics of the distillate were as follows: density 913 kg/m 3 at 20~ molecular weight 285, melting point 25~ refractive index 1.495 at 50~ viscosity 20 mm2/sec at 50~ hydrocarbon group composition (% by weight): paraffinic/naphthenic 33.7, monocyclic aromatics 21, bicyclic aromatics 13.4, polycyclic aromatics 28.7, resins 3.2; elemental composition (wt. %): H 13.3, C 85.4, S i.i. The additive used in this work, PMS-200A [methyl silicone], was added to the distillate at concentrations in the interval 0.005-0.02% by weight. This additive is used widely at concentrations from 0.002% to 0.005% as an antifoam additive in lube base stocks [2]. The test procedure consisted essentially of measuring the amplitude value and delay time of current passing through a sample when a sinusoidal voltage with an amplitude up to I0 V and a frequency of 20 to l0 s Hz was impressed on the sample, at temperatures from 30 ~ to 80~ The samples were thermostatted for 20 min before any measurements were made. On the basis of the results obtained in these measurements, calculations were performed in an ~lektronika DZ-28 microcomputer to determine the real E' and imaginary E" parts of the complex permittivity e* = e' + je", according to the formulas

Mathematical Models of Interconnections Between Composition and Properties of Oils in the Apsheron Oil- and Gas-Bearing Region of Azerbaijan

Abstract On the example of oils in the Apsheron oil- and gas-bearing region and Apsheron archipelago located in the western part of the Southern Caspian depression, the authors have developed mathematical models of a group hydrocarbon composition; interconnections between oil density and content of asphalt-resin materials, benzine, and ligroin; interconnections between oil density and viscosity and temperature; and interconnections between content of asphalt-resin properties and low-temperature fractions. The models obtained enabled us to extrapolate factual data on composition and properties of oils beyond the limits of fixed depths of burial of oil-saturated reservoirs both to a zone of great depths and increased temperatures where hydrocarbons were in a gaseous or oil and gaseous state, and to a zone of near-surface conditions where oils acquire the consistency of asphalts.

Effect of the group hydrocarbon composition of petroleum oils on the properties of polyurea lubricants

Effect of the group hydrocarbon composition of petroleum oils on the properties of polyurea lubricants

Influence of the hydrocarbon group composition of base oils on their scale-forming properties

Influence of the hydrocarbon group composition of base oils on their scale-forming properties

Solubility problems with sulphurized sperm oil replacement extreme pressure additives II: Solubility of additives in mineral base oil hydrocarbon constituents

The state of additives in lubricating fluids is very important for a better understanding of the lubrication process and the tribological stability of lubricants. This paper presents results on the influence of mineral oil hydrocarbon constituents on the state of sulphurized sperm oil replacement extreme pressure additives in hydrocarbon solutions. The hydrocarbon and structural group composition of five conventionally refined paraffinic mineral base oils was determined by well-known techniques (column chromatography and the n-d-M method). Chromatography-derived hydrocarbons and aromatic concentrates were used in model mixtures to estimate the influence of hydrocarbon groups on the state of sulphurized tall oil fatty acid esters in hydrocarbon media. The experimental results showed that the additive is not soluble in paraffinonaphthenic hydrocarbons. The sludge-forming substances are dispersible in light (monocyclic hydrocarbons) but deplete after a limited period of time. The sludge is eventually dissolved in bi- and polycyclic aromatic hydrocarbons. The latter may be used to improve the storage stability of such compositions. It is suggested that the additive is in the form of a microdispersion, solubilized by heavy aromatics in the lubricating fluid. The importance of the experimental results for the state of the additives in the hydrocarbon fluid and their relevance to lubricating performance and tribology is discussed.

Chromatographic determination of group hydrocarbon composition of automobile gasolines

Chromatographic determination of group hydrocarbon composition of automobile gasolines

Gas condensate and oil from Verkhnechonsk field of Eastern Siberia

Two condensates and three crudes from different sectors and depths of the Verkhnechonsk oil and gas field were assessed for their viscosities, molecular weights, densities, flash and solid and boiling points, cetane and octane numbers, and chemical compositions, including sulfur, nitrogen, nickel, vanadium, wax, resin, and asphaltene contents. The samples were distilled into 10-20 C fractions, reblended in proportion to their contents in the original feedstock, and analyzed by gas-liquid chromatography for product quality and hydrocarbon group composition. Distillation requirements were calculated for generating kerosene, gasoline, and diesel, jet engine, and boiler fuels from the feedstocks. Potential yields of these cuts, as well as yields of lubricating oils and paving asphalts, were evaluated for the five samples.

Crude oil from the Zaburun'e field

In order to work up recommendations for the directions to be taken in processing oil from the new Zaburun'e field in the Ural-Volga interfluvial district, a complete, unified program was used to investigate oil samples taken from depths of 905-913 and 895-903 meters from the Lower Cretaceous deposits. Density, viscosity, medium-resin content, flash point, and other processing-relevant properties were derived. The hydrocarbon group composition was assessed. Fractions distilling below 350/sup 0/C consisted mainly of high-energy isoparaffinic and naphthenic hydrocarbons. Characteristics of the diesel fuel cuts were derived. All cuts had low-temperature properties and cloud points below minus 60/sup 0/C. Lube stocks were analyzed and showed high viscosity indices, low solid points, and low sulfur contents. Straight-run resids were also evaluated.

Estimation of jet fuel coking tendency by calculation

The proposed calculation method for estimating the smoking tendency of jet fuels was developed on the premise that this property is determined primarily by the elemental and hydrocarbon-group composition of the fuel and also the density and viscosity of the fuel. In order to test this hypothesis, they obtained experimental data in a model gas turbine engine combustion chamber that is ordinarily used in determining the completeness of combustion of jet fuels by an interdepartmental method (flame tube diameter 100 mm, length 350 mm).

Influence of group composition of dispersion medium on volatility of lithium greases

The rate of evaporation of the dispersion medium in lubricating greases depends on the hydrocarbon group composition of the lube oil base stock [I]~ The paraffinic--naphthenic hydrocarbons of petroleum oils evaporate at higher rates than the aromatic hydrocarbons [2, 3]. Lithium greases formulated with oils from naphthenic-base crudes are characterized by higher volatility than greases prepared with oils from paraffinic-base crudes [4].

Crude oil from Pechanoe Ozero field of Arkhangsl'sk oblast

The crude oil sample was taken at a depth of 1558-1561 m in triassic deposits; it is light, low-sulfur, low-resin, and medium-wax, and it is distinguished by a high yield of light distillates. The characteristics of this crude are analyzed. The naphtha cuts are good feedstocks for catalytic reforming, as they contain considerable quantities of naphthenes. Analysis of the hydrocarbon group composition of 50 C cuts by adsorption on ASK silica gel showed that paraffins and naphthenes predominate in the cuts. The light kerosine cuts are characterized by good burning quality and the diesel fuel cuts have high cetane numbers, owing to the predominance of paraffinic hydrocarbons. The lube stocks recovered from the 350 degrees + has a low sulfur content, low carbon residue, and high solid point. The Pechanoe Ozero crude cannot be recommended for the production of paving asphalts.

Production of petroleum pitches from heavy cracked tars

The influence of the vacuum distillate recycle ratio on the yield of pitch from the Groznyi cracked tar, on the quantity of coke deposits, and on the time of polycondensation of volatile matter in the pitch to 65% by weight is shown. The following properties of the cracked tar are given: density; carbon residue; ash by weight; sulfur content by weight; and hydrocarbon group composition by weight which includes paraffins, naphthenes, moni-, bi-, and polycyclic aromatics, resins, asphaltenes, and carboids. The authors propose a process flow plan for a high-rate process of pitch manufacture from cracked tars on the basis of the results obtained in these studies. The process can be recommended for evaluation on an experimental-commercial scale.

Variation of hydrocarbon group composition of products from catalytic cracking of a vacuum distillate feed

The relationships in the conversion of various groups of hydrocarbons of a vacuum distillate from a medium-sulfur crude of the Romashkino type by cracking on a powdered zeolitic catalyst was investigated in a continuous pilot unit in reactors of three types: with a fluidized bed of catalyst, cocurrent-flow with a final fluidized bed of catalyst, and cocurrent-flow. A simultaneous investigation was made of the relationships in the accumulation of various groups of hydrocarbons in the craced products.

Organo-sulphur compounds and hydrocarbons of 65°–200°C distillates of Usino petroleum

1. 1. The structural group composition of hydrocarbons and organosulphur compounds of a 65°-200°C distillate of Usino petroleum was studied by mass-spectrometry together with extraction, complex-formation and adsorption chromatography. 2. 2. Organo-sulphur compounds of a low-boiling distillate are represented by saturated sulphides (0·59 wt.%), with the predominance of alkylthiamonocycloparaffins (0·43 wt.%) and thiophene compounds, mainly alkylthiopenes (0·09 wt.%) and alkylbenzothiophenes (0·05 wt.%). Thiaindane content in the distillate is 0·11 wt.%. 3. 3. The main groupes of hydrocarbons in the distillate are: naphthenes (58·5% wt.%) mainly mono- and bicyclic, paraffins (37,4 wt.%) those with an isooctane structure (63%) and aromatics (5%).

Calculational method for predicting tendency of hydrocarbon fuels to form carbon deposits

This article attempts to derive a new empirical formula for the prediction of the tendency of fuels to form carbon deposits in the combustion chambers of air-breathing jet engines. Heavy deposition of carbon in the combustion chamber of a gas turbine engine may lead to warping and in some cases burnout of the flame tube, greater nonuniformity of the temperature field ahead of the turbine, and a reduction of the turbine efficiency and a shortening of the engine life as a result of failure of the nozzle vanes and blades of the turbine. The formation of carbon deposits depends primarily on the hydrocarbon group composition and distillation curve on the fuel. Viscosity, density, surface tension, and other properties also have some influence.

Influence of dispersion medium on properties of complex lithium greases

This article investigates the properties of complex lithium (cLi) greases prepared by thickening various dispersion media, differing in hydrocarbon composition, with cLi soap (10% by weight). Distillate and residual oils produced in the USSR were used as the dispersion media. It is determined that the viscosity level of the dispersion medium does not determine the properties of the cLi greases. The presence of aromatic hydrocarbons in the distillate oils, as the content of aromatics is increased, tends to increase the viscosity-strength characteristics, increase the colloidal stability (lower the oil bleeding), reduce the heat-hardening, and give lower values of the viscosity-temperature characteristics of the greases. The quality of cLi greases based on distillate oils depends to a considerable degree on the hydrocarbon group composition of the oil and on the hydrocarbon structure. The greases based on residual oils have better rheological properties and serviceability at high temperatures than the greases based on distillate oils. It is recommended that residual oils be used as the dispersion medium for cLi greases operating at high temperatures. Includes 3 tables.

Fluid coking of heavy resids

The influence of feedstock quality on the product yields of fluid coking of heavy resides is studied. Several FC runs of types of feeds are made, by various means. Recoking, and the influence of IBP (initial boiling point) on it, is studied. Data on product yields are given. These indicate that as carbon residue, density, and c/h ratio of resid increase, liquid yield drops off, coke and gas yields increase. The only relationship found, in comparing feeds to yields, was that between product yields and carbon residue of feedstock. This behavior is due to the hydrocarbon group composition of heavy resids, where the polycyclic core is freed from a loose periphery of molecules during FC, forming gas and liquid fractions. This correlation can be used to estimate product yield from resids with carbon residue of 12-47%.

Evaluation of thickening power of V.I. improvers

This article reports on tests of a broad group of additives and oils differing in hydrocarbon group composition with regard to whether viscosity varies exponentially with the additive content. Finds that the dependence of the compounded oil viscosity on the additive content follows an exponential equation where K is the coefficient of thickening power and C is the additive content. Thus, in developing additive oil formulations, the effectiveness of the V.I. additives can be evaluated on the basis of the coefficient K. Points out that the influence of polar components such as aromatic hydrocarbons present in the oils may be so significant that the thickening power of additives with 20,000 and 60,000 molecular weight in I-40A oil may be lower than in the naphthenic white oil NKM-40.