Mathematical Modeling of the Process Hydrotreatment of Diesel Fuel Based on the Kinetic Characteristics of Its Fractions

Abstract

The principles of mathematical modeling of the diesel fuel hydrotreatment process as a multicomponent reaction system are considered. Feedstock containing a large number of organosulphuric components from the standpoint of increasing the level of model adequacy and calculation accuracy can be characterized by the total sulfur content in the raw material as a whole (1), the total sulfur content in pseudocomponents in the feedstock or its narrow fractions (2), the concentration of individual organosulphuric substances (3). It is shown that in cases 1 and 2, the concept of the reaction rate constant as a constant that characterizes the physico-chemical process is degenerate, and in calculations it should be considered as a kinetic characteristic that takes into account the inhomogeneity of the chemical process over time. As the hydrogenated feedstock comes into contact with the hydrogen-containing gas, the most active organosulfuric components with a high reaction rate constant are first hydrogenated on the catalyst, and at the final stage of the process, the less active components with a low reaction rate constant are hydrogenated. Examples of calculating the dependence of the kinetic characteristic and the total sulfur content in the hydrogenate in two broad fractions of diesel fuel on the time of contact of the reaction medium with the catalyst and the subsequent compounding of the fractions into diesel fuel.