New characterization models for macroscopic chemical-hydrodynamic behavior of catalytic cracking riser-reactor with interactive patterns of severe operating conditions using CFD calculations

Abstract

Background

FCC is the core of refining technologies for production of high-valued chemicals including, light olefins, and fuels. Global capacity of catalytic cracking unites is projected to grow from 14.4 to 15.8 million barrels per day from 2022 to 2026. Moreover, global production of 57 % ethylene, 42 % propylene and 69 % butylene is based on deep/fluid catalytic cracking. Therefore, optimization of catalytic cracking process is our indispensable industrial approach.

Methods

This study is optimization of industrial catalytic cracking unit for maximizing the yield of light gases, gasoline and gasoil conversion using CFD calculations. Hydrodynamic behavior and performance of the riser-reactor was investigated at severe operating conditions, including feed temperature, catalyst temperature and catalyst to oil ratio (CTO) in the range of 788–903 K, 813–1013 K and 6–18, respectively. New characterization models were proposed for macroscopic chemical-dynamic behavior of the process. Models validated with ANOVA analysis, RSM methodology.

Significant findings

Results showed that the maximum products yield and gasoil conversion occur between 4 and 8 s. It was obtained that the maximum yield of nearly 12 wt% light gases, 38–39 wt% gasoline and 54 % conversion is possible for this geometry of industrial unit via optimization of operating conditions. Coefficients of obtained models and interactive patterns of operating conditions showed that CTO is the most influential parameter on riser-reactor performance.