The deviation of density and viscosity values of oil mixtures from those calculated according to the additivity rule has been examined. Mathematical models have been developed for determining the properties of mixtures with different compositions taking into account the group composition of the source components. Mixtures containing components with a high content of alkanes and a low content of arenes have been found to be characterized by extreme deviations of density towards the maximum and kinematic viscosity towards the minimum. The created models were validated and compared with existing methods of describing the oil physicochemical properties. An approach to the creation of optimal from a technological point of view formulation for compounding oil of different types is proposed.

The study is devoted to the determination of kinetic parameters of the process of asphalt-resin-paraffin deposits dissolution by oil fractions, solvents and compositions based on them. The study of the kinetics of deposits dissolution and the effect of additives on this process is relevant, as the use of solvents will reduce the cost of cleaning and repairing process equipment of refineries. A series of experiments was performed to determine the kinetic regularities of dissolution of different types of asphalt-resin-paraffin deposits in petroleum solvents of different fractional composition and the effect of dispersing agents on this process. Crude distilled oil fractions 110–1500С, 150–2000С and 140–2430С were shown to be the most effective for dissolving the asphalt-resin-paraffin deposits. The use of dispersant agents increases the degree of solubility of the components of the asphalt-resin-paraffin deposits. The kinetics of dissolution process obeys the Erofeyev-Kolmogorov equation.

We developed the methods for preparation of the following natural and biosynthetic surfactants of different composition based on rapeseed oil: diethanolamides, mono-, diglycerides of fatty acids, their sulfosuccinates and phosphatides. The completeness of chemical transformations and formation of target functional groups were confirmed by infrared spectroscopy. The influence of the addition of natural and biosynthetic surfactants on the low-temperature properties of oil fuels and tribological characteristics of lithium grease is analyzed. The feasibility of using these substances as depressant additives to oil fuels in the amount of 0.25–0.5 wt.% (it was achieved the reduction of the pour point of oil fuel of 7–80C) and as anti-emergency additives to lubricants (the diameter of the wear spot decreased from 0.8 to 0.38 mm when using additives) was experimentally confirmed.

The study examines the existing asphaltene flocculation inhibitors in oil dispersed systems — oil-soluble surfactants of various nature. It is proposed to use cheap surfactants of vegetable origin as flocculation inhibitors — phosphatide concentrate and sodium sulfosuccinate. The process of flocculation of asphaltenes on model mixtures of asphaltenes of different concentrations with toluene and precipitants, as well as the influence of the proposed inhibitors on the aggregative stability of the mixtures, was studied. The flocculation starting point (onset point) of each mixture was determined by the photocolorimetric method.