NUMERICAL DESCRIPTION OF THE DISTRIBUTION OF n-PARAFFINS CONTENT IN VACUUM GAS OIL AND THEIR REACTIVITY IN THE HYDROCRACKING PROCESS

Currently, the process of hydrocracking of heavy petroleum feedstocks is one of the main processes that makes it possible to increase the depth of oil refining and to obtain high-quality motor fuel components, including diesel fuel components with improved low-temperature properties. In this paper, a review on the existing modelling approaches and models of the heavy oil feedstock hydrocracking process is presented. The object of the research is the process of vacuum gasoil hydrocracking. The work proposes the scheme of chemical transformations in the process of hydrocracking and the model of the process. The distinctive feature of the proposed chemical transformations scheme and a model is taking into account the hydrocracking reactions of individual n-paraffins. It is proposed to determine the content of individual n-paraffins in the feedstock of the process (vacuum gas oil) by the number of carbon atoms in the molecule based on the probability distribution, using the Gaussian function as a probability density function. The reactivity of individual n-paraffins in the hydrocracking reaction was taken into account via thermodynamic characteristics of the reactions of each individual n-paraffin determined using quantum-chemical methods. The calculation of the detailed composition of the target diesel product including the content of n-paraffins provides determination of cold filter plugging point, which is influenced by the content of n-paraffins to the most extent. The developed detailed model of vacuum gasoil hydrocracking process includes the equations for calculation of changes in concentrations of reacting component and change in the temperature of the process. The proposed approach to the modelling of the hydrocracking process makes it possible to optimize the process taking into account the detailed composition to get the maximum yield of low freezing diesel fuel. For citation: Belinskaya N.S. Numerical description of the distribution of n-paraffins content in vacuum gas oil and their reactivity in the hydrocracking process. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 11. P. 95-105. DOI: 10.6060/ivkkt.20246711.7039.