CFD MODELING AND SIMULATION OF AN INDUSTRIAL RESIDUE FLUID CATALYTIC CRACKING (RFCC) RISER

A multi-fluid Eulerian model is applied to simulate the flow behavior and
catalytic cracking reactions in the riser of an industrial Residue Fluid Catalytic
Cracking (RFCC) unit in Khartoum Refinery Company (KRC), Sudan. In this riser
atmospheric residue is cracked into diesel, gasoline, lighter gases and coke over
Zeolite catalyst surface. 2D and 3D CFD models are developed for the solid - gas
flow in the riser and solved using ANSYS FLUENT in Workbench 14. The
quadrilateral mesh for 2D model and the hexahedral mesh for the 3D model are sized
in a grid independent test. In the hydrodynamic model, the k-e gas-solid turbulent
flow per phase model is used, and the particle-level fluctuations are modeled in the
framework of the kinetic theory of granular flow (KTGF) to simulate the flow in the
riser. On validating this hydrodynamic model, the particle volume fraction and
velocity profiles show very good agreement with the published experimental data.