Development of a Two-Fluid Hydrodynamic Model for a Riser Reactor

ANSYS Fluent is used to examine the mixing of catalyst zeolite particles with petroleum feedstock and water vapor in a fluid catalytic cracking (FCC) riser. A two-fluid model is developed for tracking catalyst particles and gas mixture in a riser, modeling the granular and gaseous phases as two interpenetrating continua. The hydrodynamic flows are analyzed with the aim to single out the principal physical effects that determine the distribution of particles. The results are compared with a study that is based on a non-isothermal reactive model. It is demonstrated that the simplistic purely hydrodynamic model generates similar flow fields. The developed model is valuable for improvements of modern FCC risers. The model is applied for understanding the hydrodynamics of an S-200 KT-1/1 industrial unit

A Model of Catalytic Cracking: Product Distribution and Catalyst Deactivation Depending on Saturates, Aromatics and Resins Content in Feed

The problems of catalyst deactivation and optimization of the mixed feedstock become more relevant when the residues are involved as a catalytic cracking feedstock. Through numerical and experimental studies of catalytic cracking, we optimized the composition of the mixed feedstock in order to minimize the catalyst deactivation by coke. A pure vacuum gasoil increases the yields of the wet gas and the gasoline (56.1 and 24.9 wt%). An increase in the ratio of residues up to 50% reduces the gasoline yield due to the catalyst deactivation by 19.9%. However, this provides a rise in the RON of gasoline and the light gasoil yield by 1.9 units and 1.7 wt% Moreover, the ratio of residue may be less than 50%, since the conversion is limited by the regenerator coke burning ability

Development of a formalized scheme of hydrocarbon transformations in the catalytic cracking for forecasting the individual composition of gases

The work aims to create a formalized scheme of the hydrocarbons transformation in the catalytic cracking with the participation of high-molecular hydrocarbons of vacuum distillate in order to predict the gasoline group composition and the gases individual composition. Thermodynamic parameters of the most probable reactions of cracking gases formation under technological conditions of the process using the reference data and Density Functional Theory are determined; the features of the mechanism of hydrocarbon transformations on acid catalysts determining the high content of isoalkanes, alkenes, aromatic hydrocarbons in cracking products are taken into account