Sensitivity analysis of the mathematical model of catalytic reforming of gasoline

Abstract

Detailed kinetic model is required to study one of the most important oil refining processes, which is catalytic reforming. The difficulty arises in connection with a large number of components of the reaction mixture and a large number of stages of chemical transformations in developing the kinetic model. The conversion scheme of catalytic reforming of gasoline includes 171 stages. The individual components are combined in 37 groups belonging to the following classes: normal paraffins, isoparaffins, five-membered naphthenes, six-membered naphthenes and aromatic hydrocarbons. An alternative may be reduced reaction mechanisms that are applicable to solve the problem and provide realistic description of the process. In this paper, the sensitivity analysis technique of the mathematical model was used. It was developed by the authors to obtain a reduced mechanism. The new technique has been developed for analyzing complex kinetic schemes and reducing kinetic models to sizes acceptable from the point of view of accuracy of description and ease of practical use. In this work, the global Sobol method was used to obtain a reduced model of catalytic reforming of gasoline. The model parameters were determined by a global analysis of the sensitivity of the functional of the mathematical model to the variation of the rate constants of the stages. The least influential stages of catalytic reforming of gasoline were revealed. The influence of the exclusion of these stages on the kinetics of the process from the chemical point of view is investigated. The reduced scheme for the catalytic reforming of gasoline is proposed. It provides quite satisfactory agreement both in temperature profiles and in concentration profiles of significant substances.