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THE PURPOSE. The purpose of this work was to use the associated paradigm for a correct quantum-chemical description of non-catalytic and catalytic supercritical fluid processes of transesterification of triglycerides with alcohols and hydrolysis of triglycerides and to model a one-stage process for obtaining biodiesel fuel, carried out under supercritical fluid conditions with its subsequent scaling to the commercial level.METHODS. The Gaussian09 software product was used to describe quantum chemical studies. The process modeling was carried out using the ASPEN Plus® v2006 software product. The behavior of thermodynamic systems at high temperatures and pressures is modeled using "RK ASPEN EOS". For modeling processes carried out at low pressures, mathematical models UNIQUAC and UNIFAC-LL were used. The scaling of the process was carried out in the VMGSim program.RESULTS. The third part of the review focuses on the quantum-chemical modeling of the transesterification reaction carried out under supercritical fluid conditions. It is shown that taking into account the associative paradigm makes it possible to obtain calculated reaction rate constants that agree in order with the experimental values. And also an analysis was carried out and the results of modeling the process of obtaining biodiesel fuel and scaling it to a commercial level, with a capacity of up to 9000 tons / year, were presented.CONCLUSION. The conducted analysis showed that biodiesel fuel can be a competitive fuel in our and the world market.

THE PURPOSE. The purpose of the work was to systematize the results of the work of domestic and foreign authors on the thermophysical properties of media and substances involved in the process of obtaining biodiesel fuel. METHODS. To measure the isobaric heat capacity, the predominant use is given to the methods of heat-conducting and scanning calorimeters, the measurement of the thermal conductivity by the heated filament method. Kinematic and dynamic viscosities are measured, respectively, on standard glass viscometers at atmospheric pressure and by the drop weight method. RESULTS. The results of a study of a wide range of thermophysical properties of thermodynamic systems involved in the process of obtaining biodiesel fuel under supercritical fluid conditions are presented. Attention is paid to the density, isobaric heat capacity, thermal conductivity, dynamic and kinematic viscosity of both the feedstock and the resulting biodiesel fuel, presented in a wide range of temperature and pressure changes, including nearcritical, as well as taking into account the thermal effects caused by the dissolution and change in the structures of substances under the influence of fluid reagent. CONCLUSION. The presented data will be necessary at the stages of designing and scaling a particular technology for the production of biodiesel fuel, both on a laboratory scale and at an industrial level.

THE PURPOSE. The presented work aims to analyze the realities and prospects for the use of working media in the production of biodiesel fuel, including the supercritical fluid state. METHODS. Methods for obtaining biodiesel fuel are considered, including the method of transesterification, as the most common, as well as methods of pyrolysis and the combined process of hydrolysis and esterification. RESULTS. Traditional (industrially used methods for producing biodiesel fuel), as well as methods involving supercritical fluid media at their core, are considered. Along with a description of the state of affairs on the issues under discussion in the world, the results of our own research carried out by the team of authors of this article are also presented. Attention is drawn to the prospects of ultrasonic emulsification of the reaction mixture and the use of heterogeneous catalysts in order to mitigate supercritical fluid conditions for the process of obtaining biodiesel fuel and save energy. The conditions for obtaining biodiesel fuel without free glycerol and converting it into a fuel component are also discussed. CONCLUSION. Transesterification carried out under supercritical fluid conditions provides significant advantages over the traditional process and, especially in terms of the possibility of using a variety of raw materials, including low-quality ones, facilitates the procedure for isolating the final product and, finally, makes it possible to switch from relatively small-scale implementations with batch reactors to high-performance plants with flow reactors.