Modeling Wet Air Oxidation of Sodium Acetate in a Bubble Column

Abstract

Scale-up bubble columns for wet air oxidation (WAO) represent a novel solution to the growing problem of sodium acetate-containing waste discharge. This study used an axial dispersion model to simulate a reactor at a high temperature of 320 °C. By minimizing the structure size and gas fed into the system, the estimated optimal reactor dimensions were obtained. At the optimized reactor diameter, total height, initial oxygen partial pressure, and superficial gas velocity of 1 m, 7 m, 40 bar, and 0.07 m/s, respectively, a degradation efficiency of over 90% was obtained, at which the residual concentration of sodium acetate degraded from 700 mol/m3 to 70 mol/m3. The axial distributions of the dissolved oxygen, sodium acetate, and oxygen concentrations in the gas were nearly uniform. The bubble column reactor exhibited an intermediate state between well-mixed flow and plug flow for both liquid and gas.