EFFECT OF HYDRODYNAMIC CONDITIONS IN AN I NDUSTRIAL-SCALE FLUIDIZED-BED REACTOR ON SELECTIVITY AND YIELD TO ACRYLNITRIL BY AMMOXYDATION OF PROPYLENE

Ammoxidation of propylene to acrylnitril (Sohio process) was selected as a model reaction in order to study the effect of the hydrodynamic c onditions in an industrial-scale fluidized-bed reactor on the selectiv ity and yield to an intermediate product. The fluidized-bed reactor wa s simulated applying a two-phase model. For describing chemical reacti ons a global kinetics determined for the Bi-Mo-O catalyst was chosen f rom the literature. The simulation results indicate that the mass tran sport limitation between bubbles and the emulsion phase as well as bac k-mixing of gas in the emulsion phase results in the drop of selectivi ty and yield to acrylnitril compared to the plug-flow and CSTR reactor . The possibility of the improvement of the reactor performance by var ying particle diameter or by applying a multistage fluidized bed was a lso studied in the paper.