Numerical Simulation of the Gas-Solid Two-Phase Flow-Reaction Process in a Maximizing Isoparaffin Process Reactor

Area of Science:

• Chemical Engineering
• Multiphase Flow Dynamics
• Catalysis

Background:

• Fluid catalytic cracking (FCC) processes involve complex reactions and phase transitions.
• Optimizing FCC, specifically the maximizing isoparaffin process (MIP), is crucial for efficient, low-pollution, and cost-effective catalytic device design and operation.

Purpose of the Study:

• To develop and validate a coupled flow-reaction model for an industrial MIP riser reactor.
• To investigate the impact of operating variables on the gas-solid two-phase flow-reaction process in MIP.

Main Methods:

• Employed an Eulerian-Eulerian model coupled with an 11-lump kinetic model.
• Integrated a drag model based on the energy-minimization multiscale model into FLUENT via a user-defined function (UDF).
• Validated the model against industrial data for catalyst temperature and product component concentrations.

Main Results:

• The coupled model accurately predicted catalyst temperature distribution and outlet product concentrations, confirming its reliability.
• Analyzed catalyst particle velocity profiles in different riser zones (prelifting, first, and second reaction zones).
• Determined that increasing catalyst-to-oil ratio affects product yields (e.g., decreases diesel, increases gasoline and light gases).

Conclusions:

• The established coupled flow-reaction and drag models are effective for simulating industrial MIP riser reactors.
• Operating variables like catalyst-to-oil ratio and catalyst inlet temperature significantly influence product distribution.
• The findings offer important guidance for optimizing MIP process design and operation.