Two-phase model for a catalytic turbulent fluidized-bed reactor: Application to ethylene synthesis

A turbulent fluidized-bed (TFB) reactor for the ethylene synthesis by catalytic oxidation of natural gas was simulated employing a two-phase model, and the hydrodynamic structure of the TFB was characterized for the MgO catalyst particles. The overall gas phase distribution in bubbles and emulsion phases was estimated by using the probability distribution function of local voidage fluctuations in the bed. The mean voidage corresponding at the bubble phase increased with gas superficial velocity according to a first-order model, and the mean voidage in emulsion phase rose proportionally with gas superficial velocity. Moreover, the emulsion/bubble voidage ratio at the center of the bed was almost constant in the turbulent regime, and radial profiles of the phase distribution ratio were observed in the turbulent bed. The two-phase model developed predicted satisfactorily the experimental data and can be used to quantify the influence of homogeneous and catalytic reaction in the TFB for the oxidative coupling of methane. (C) 1999 Elsevier Science Ltd. All rights reserved.