Nikolay A. Mironov

Features of the composition of vanadyl porphyrins in the crude extract of asphaltenes of heavy oil with high vanadium content

ABSTRACT Features of changes in the content of nickel and vanadium in heavy oils and their asphaltenes are shown for various fields of Volga-Ural region (Russia). The change in the content of vanadyl complexes in the studied asphaltenes upon increase of vanadium content was demonstrated. Several polar solvents (acetone, N,N-dimethylformamide, isopropanol, acetonitrile) are compared as extractants to obtain crude extracts of vanadyl porphyrins from asphaltenes with vanadium content of 0.44 wt%. The opportunity of more efficient extraction of vanadyl porphyrins from asphaltenes is shown by deposition extraction method, particularly when using N,N-dimethylformamide. Absorption spectra and matrix-assisted laser desorption/ionization (MALDI) mass spectra of the extracts obtained were analyzed. For extracts with maximum content of vanadyl porphyrins, the presence of mainly etio- and deoxophylloerythroetioporphyrins was revealed. It was shown that proportion of etio-type vanadyl porphyrins does not exceed 75% of the amount of porphyrins of DPEP-type. A maximum of molecular weight distribution in both types falls on a homologue of vanadyl porphyrin C31 containing nine carbon atoms in the alkyl substituents.

Vanadium and paramagnetic vanadyl complexes content in asphaltenes of heavy oils of various productive sediments

ABSTRACT Using the atomic absorption spectrometry and electronic paramagnetic resonance techniques, we have investigated the features of vanadium and vanadyl complexes content in asphaltenes of heavy oils of Permian and Carboniferous productive sediments in the Volga-Ural oil and gas basin deposits. The investigation has been carried out using the heavy oils example, where the asphaltene content ranges from 5.1 to 21.2 wt%, and vanadium content varies in the range of 0.009–0.165 wt%. The specificity of asphaltene–vanadium relationship has been found for heavy oils of various productive sediments. It has been demonstrated that vanadium and vanadyl complexes content in asphaltenes of heavy oils in separate productive sediments varies in the certain range limits.

Structural-group composition and properties of heavy oil asphaltenes modified with sulfuric acid

ABSTRACT Details of the change of structural-group composition of heavy oil asphaltenes modified with sulfuric acid and oleum depending on the process conditions have been determined. The effect of the amount and concentration of sulfuric acid, exposure time, and elevated pressure has been evaluated. The formation of sulfo-, sulfono-, phenolic hydroxyl, carboxylic, and carbonyl functional groups has been detected in Fourier transform infrared (FTIR) spectra for the obtained sulfonated asphaltenes. Spectral coefficients have been calculated for asphaltenes and products of their sulfonation according to the main absorption bands in FT-IR spectra. Analysis of spectral coefficients has indicated the relationship of the fraction of newly formed functional groups in sulfonated asphaltenes and process conditions of sulfuric acid modification. The obtained sulfonated asphaltenes have been analyzed as sulfocationites with the evaluation of sorption capacity. It has been shown that the successive modification of heavy oil asphaltenes with sulfuric acid and oleum gives sulfocationite with the static exchange capacity of 3.39 meq/g. The relationship of spectral coefficients and sorption characteristics of sulfonated asphaltenes has been determined.

Composition of the Products of Thermolysis of Heavy Oil with the Addition of Light Hydrocracked Naphtha

Abstract A series of experiments has been carried out on the thermolysis of heavy oil using 2.5–10.0% light hydrocarbon naphtha additive of vacuum gasoil prepared from conventional oil. It has been shown that the employment of the additive increases the conversion of heavy oil, avoids coke formation in the products of thermolysis as compared to the basic process without additive, and does not prevent the decrease in the viscosity of the products during thermolysis. It has been revealed on the example of the heavy oil of Ashal’chinskoe deposit (Russia) that the thermolysis with the addition of light naphtha gives a liquid product with the yield higher than 97% and the viscosity of less than 80u2009mm2/s.

Distribution of vanadium and vanadyl porphyrins during fractionation of resins of heavy sulfurous oils

ABSTRACT Features of the content and distribution of vanadium and vanadyl porphyrins in the fractions of resins, which were obtained by separation using column chromatography on silica, have been studied on heavy sulfurous oils of various deposits of the Volga–Ural basin (Russia). The difference of the vanadium and vanadyl porphyrin contents in the fractions of oils of various production complexes has been shown. Features of structural–group composition and predominant types of vanadyl porphyrins in the fractions of resins have been determined.

Composition and sorption properties of asphaltene sulfonates

ABSTRACT The sulfonation of the dissolved oil objects by concentrated sulfuric acid was carried out at 60, 80, 100 oC and the resulting products with a structural-group composition similar to sulfonated asphaltenes were obtained. Structural-group composition of sulfonated oil products was established by Fourier transform infrared spectroscopy and the relative contents of sulfo-, sulfono- and carboxyl ionogenic functional groups was determined on the basis of spectral coefficients. The sorption capacity of sulfonated oil products (10-13 mg/g for Ca2+ and 14–18 mg/g for Cu2+) was determined by atom-absorption spectroscopy. It was established that the sorption characteristics of sulfonated oil products are determined by the total contents of asphaltene-resin components in starting oil objects and temperature of the sulfonation process.