In this study, we present the development of a three-dimensional CFD model for a lab-scale FBR performing ethylene epoxidation. The governing equations were solved using the Finite Volume Method in ANSYS Fluent (2024R2) under transient conditions. The Eulerian-Eulerian multiphase framework was used to model gas-solid hydrodynamics, reaction kinetics, and interphase mass transfer. Two parallel reactions were included: ethylene epoxidation and total combustion, implemented via volumetric source terms. Catalyst properties and drag models were defined based on industrial formulations, and solid recovery was maintained at 100% to represent a realistic fluidized environment.
The model investigates the influence of key operating and design parameters, including superficial gas velocity (spanning different fluidization regimes), catalyst particle diameter, bed height, and reactor pressure, on EO conversion and selectivity. A major focus is also placed on the prediction and mitigation of thermal hotspots using isothermal and energy-coupled configurations. The temperature distribution will be analyzed in relation to selectivity loss and safety limits.
To complement the CFD work, a steady-state process simulation of the EO production loop is being developed in Aspen HYSYS, allowing for upstream-downstream integration, energy targeting, and utility analysis. Process data will serve as boundary conditions and validation points for the CFD model.
This integrated digital framework aims to guide future experimental investigations and contribute to the design of safer, more selective, and scalable EO production systems.