A Computational fluid dynamics (CFD) comparison of 3-Lump and 4-Lump kinetic models for predicting gasoline, light gases and coke yield in fluid catalytic cracking (FCC) riser

School of Chemical & Materials Engineering, National University of Sciences &, Technology Islamabad 44000, Pakistan

^a Corresponding author: ahsan@scme.nust.edu.pk

Received: 18 July 2014
Accepted: 11 December 2014

Abstract

In this study a comparison of 3-lump and 4-lump kinetic models predicting the yield of gasoline, light gases and coke in FCC riser has been done. Commercial CFD software with K-epsilon turbulence model is used to investigate the reactions occurrence between fluid and solids in a fluidized bed. An important feature of this model is that its kinetics includes partial differential equations. This provides accurate predictions of product yields in the FCC riser. In this simulation different process variables such as temperature and feed rate are changed to investigate the effect on product yields. Time accurate transient problem is solved with the prediction of yield profiles of gas oil, gasoline, light gas and coke. The output curves demonstrate the breaking of heavy hydrocarbon in the presence of catalyst. An approach proposed in this study shows good agreement with the experimental and numerical data available in literature.