Model for the simulation of light naphtha cracking in an inverted cyclone reactor

Abstract

Light naphtha thermal cracking to produce ethylene and propylene in an inverted cyclone reactor has been proposed not only as an alternative for the cracked light naphtha recovery but also as a way to improve conventional cracking. A mathematical model was developed in order to assess the performan ce of this new process under changing operating conditions and design reactor parameters. A kinetic scheme for the naphtha cracking based on molecular reactions was selected and the mass and energy balances were performed. Rosenbrock's numerical method was used to find the numerical solutions to the model's equations. The simulation results allowed for a clear description of the light naphtha cracking behavior in an inverted cyclone reactor, showing that the heat exchange between solid and gas phases determines the conversion and product yields. Also, solid initial temperature and solid mass flow rate were found to be the operational parameters with the greatest impact on products formation while the steam temperature and steam/oil ratio are of lesser importance. In addition, injection angle determines the residence time, hence significantly affecting the overall performance.