A design kinetic and hydrodynamic study of a coupled dual fluidized bed MTO reactor-regenerator system

Abstract

The methanol-to-olefin (MTO) process, employing a dual-fluidized bed system, has introduced a new and reliable route for producing light olefins. This study intends to employ a comprehensive approach to simultaneously design and evaluate the reactor and regenerator performance. Namely, an inclusive design for a pilot-scale MTO system, encompassing the reactor, regenerator, interconnected catalyst transfer pipelines, and other critical operational aspects, is presented. The computational fluid dynamics (CFD) method using the Eulerian-Eulerian model was used to evaluate hydrodynamics, while the coupled reactor-regenerator kinetic model was developed by combining reaction kinetics with the two-phase model. The models were validated against experimental data and demonstrated a promising agreement. More importantly, an innovative procedure was devised to apply these modelling techniques to design this dual-fluidized bed system—the final design for the 10 kg catalyst inventory in the reactor at the pilot scale. The system achieves methanol conversion of 98.87 %, with ethylene and propylene product mass fractions of 45.51 % and 37.79 %, respectively.