THE QSPR MODEL FOR PREDICTION OF OCTANE NUMBERS OF HYDROCARBONS OF A SERIES OF ALKENES BY TOPOLOGICAL CHARACTERISTICS OF MOLECULES
Authors:   Ufa State Petroleum Technological University, Koledin O. S. , Dolomatov M. Yu. ,   Ufa State Petroleum Technological University, Kovaleva E. A. ,   Ufa State Petroleum Technological University, Garipov R. V. ,   Ufa State Petroleum Technological University, Valeev M. R. ,   Ufa State Petroleum Technological University
Published: March 2022

Relevance Modeling, optimization and design of processes in the technology of oil refining and organic synthesis, as well as the use of new chemical and technological processes involv ing hydrocarbon systems with the calculation of physical and chemical properties (РCS) of liquids and gases. The accuracy of calculations plays an observed role in the calculations of oil refining and organic synthesis processes, as well as approximate reactor processes, fractionation and heat exchange equipment. Despite the availability of РCS databases, the search for adequate initial data takes a long time at the stage of the entire development or design process, since the РCS of many hydrocarbons remains unknown. Aim of research To develop a quantitative Structure-Property Ratio (QSPR) model for octane hydrocarbons of a series of alkenes. Research methods To predict the octane numbers of normal and substituted alkenes — components of catalytic cracking, a nonlinear multivariate regression model Quantitative Structure-Property Relationship (QSPR) is proposed. The objects of the study were 30 hydrocarbons of a number of alkenes, selection in the basic and test samples, made randomly using computer data of physical and chemical properties. The model associates a set of descriptors with the octane numbers — the topological characteristics of their molecular graphs: the Wiener index, the Randich index and the magnitude of the quadratic dependence of bone structure, which affect the octane numbers and reflect the main structural and chemical factors, such as the length and branching of the carbon skeleton, and sensitive parameters. molecules. Results The adequacy of the models was confirmed by statistical data processing, so the coefficient of determining the models is 0.856. For the quality characteristics of the QSPR model, the multiple correlation coefficient r = 0.925 was calculated, which suggested a force relationship between the proposed topological characteristics of hydrocarbon molecules and their octane numbers. To assess the statistical stability of the model, a correlation correction was used. The maximum absolute and relative errors for octane number sampling tests are 4.0 units and 4.1 %, respectively. The statistical calculation, which makes it possible to judge the adequacy of the predicted indicators, their compliance with the reference data, is the standard regression error of 6.5 units. The small value of the standard error of the regression in comparison with the values of the dependence of the applicable adequacy of the proposed model. The model adequately uses the octane numbers of linear and branched alkenes and can be used to predict the octane numbers of gasoline components.