An Algorithm for Pseudocompound Delumping and Lumping into Homologous Groups

Abstract

An algorithm for pseudocompound delumping and lumping into homologous groups is developed. This algorithm is useful for modeling refineries when using commercial simulators and detailed reactor models. Generally, commercial simulators represent petroleum fractions using pseudocompounds; however, reactor models and their kinetics are based on known compounds. This algorithm delumps the pseudocompounds into homologous groups that are represented by model compounds, which are then used by a detailed reactor model. After the reaction, the outlet stream is lumped again to pseudocompounds that are used in the remaining operations of the commercial simulator. The lumping operations are based on mass balance principles and fundamental properties of the hydrocarbon mixture. This algorithm is applied to the modeling of a hydrotreatment unit that belongs to the Mexican System of Refineries which uses a detailed three phase trickle bed reactor. The problem is to delump and lump the pseudocompounds, which represent light gas oil, into paraffins, naphthenes, and mono and polyaromatics. Results show a good agreement with industrial data.