Investigation of multi-field coupling performance in a binary-mixture fluidized bed reactor for FCC-PDH coupling process: Effects of key process parameters

Abstract

The multi-field coupling performance of a binary-mixture fluidized bed reactor was investigated for the novel FCC-PDH coupling process, focusing on key process parameters. A validated numerical model demonstrated deviations within ±10 % for flow and reaction simulations. Results revealed favorable temperature profiles and reaction equilibrium, with a 113.15 K reduction in catalyst circulation temperature under an initial packing temperature of 773 K and a regeneration temperature of 873 K. This reduction optimized FCC reaction conditions by lowering the oil-catalyst contact temperature. Propane conversion exceeded 70 %, with a distinct “secondary plateau period” observed in axial reaction intensity, highlighting the interplay between heat transfer and reaction kinetics. Increasing the catalyst packing temperature from 773 K to 873 K reduced the thermal equilibrium height from 3200 mm to 2500 mm and boosted propane conversion from 80.11 % to 99.51 %, despite a decrease in the temperature drop of the circulating catalyst from 195.1 K to 89.9 K. Lower regeneration temperatures improved temperature uniformity and reduced catalyst temperature drops. At a flotsam packing ratio of 0.28, the optimal conversion of 81.63 % was achieved, ensuring efficient mixing and continuous endothermic dehydrogenation. These findings provide valuable insights for optimizing FCC-PDH industrial designs, emphasizing the importance of parameter tuning to enhance process performance and energy efficiency.