Case Studies of Optimizing and Troubleshooting FCC Reactors and Regenerators

Presented By

- CPFD (Computational Particle Fluid Dynamics)

Conference: Galveston 2013

The optimal design and operation of FCC reactors and regenerators is based on ensuring the reacting gas-particle flow within these major components of the FCC are optimal. An FCCU optimized though a better understanding of these flows will exhibit better spent cat distribution, improved mixing, more uniform temperature distribution, lower cat losses, and improved service life through reduction of erosion. Regenerators in particular are responsible for the majority of the emission from the FCCU, so improving regenerator operation can lead to reduced NOx and SOx levels plus eliminate conditions such as afterburning.

Measurements to determine fluidization behavior are notoriously difficult to obtain in FCCU equipment. Meanwhile, it has historically been impossible to model the reacting gas-particle physics with sufficient accuracy to make design and operational decisions in a practical time frame. However, advances in computational modeling for multiphase, reacting gas-solid flows now make it practical  to model FCC reactors and regenerators at full scale and in a practical time frame. This proprietary technology is called Computational Particle Fluid Dynamics (CPFD®) and is incorporated in the Barracuda VR software package. Accurate simulations of 3D, time-transient, reacting gas-particle flows now allow engineers to quickly and cost-effectively analyze multiple FCC design or operational scenarios. Using the insight gained from these computational models, plant designers and operations personnel can optimize plant performance, increase reliability, stretch operational periods, and extend overall plant operating life while at the same time reducing emissions and saving operating costs (e.g., reducing makeup cat requirements).

The presentation will highlight multiple case studies showing successful use of these complex 3D gasparticle flow models for FCC equipment. The modeling technology described has been in commercial use for some time by operators such as Marathon Petroleum, Total S.A., and LyondellBasell and by FCC technology licensors such as UOP, Shell, IFP, Idemitsu and Technip USA, plus catalyst manufacturers such as Johnson Matthey INTERCAT and BASF. Principle applications are design, troubleshooting, and operational optimization of FCC units, including reactors, regenerators, and downstream gas clean-up equipment.

The purpose of this presentation is to demonstrate that it is possible today to achieve more optimal design and operation of FCC fluidized beds through the insight gained from low-cost, detailed computational modeling of the core equipment, whether reactors or regenerators. This is possible because engineering-grade simulations can now be done using a full 3D model of the primary gasfluidized beds, with millions of discrete particles (catalyst), each undergoing chemical reactions (combustion).

CPFD and Barracuda VR represent an enabling technology for meeting ever increasing economic and regulatory demands on refinery operations while reducing the risk associated with making changes to critical refinery equipment.

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