ANÁLISE HIDRODINÂMICA DE UM REATOR ELETROQUÍMICO DE LEITO POROSO A PARTIR DOS MODELOS DE DISPERSÃO AXIAL E DE RECIRCULAÇÃO DO FLUIDO EM LOOP

Abstract

Wastewater contaminated with hydrogen sulfide can be treated using electrochemical oxidation reactors. The residence time of the contaminant inside the reactor must be adequate for desirable conversions to be achieved. The flow pattern and the non-idealities of a reticulated vitreous carbon porous bed electrochemical reactor were investigated and characterized using experimental residence time determination tests. The pulse disturbance methodology was used to obtain residence time distribution curves using sodium chloride as a tracer for three distilled water flow rates: 3 L·h^-1, 4 L·h^-1, and 5 L·h^-1. The axial dispersion theoretical models and the loop recirculation model were evaluated to define the most appropriate configuration regarding the experimental curve of residence time distribution. The models that best described the experimental data were the axial dispersion models with closed-open boundary condition, and the loop fluid model with three stages of ideal mixing. The theoretical results confirm that both models represent a reactor flow behavior close to that of a continuous-stirred tank reactor. Both models may be used to predict the hydrodynamic behavior of the reactor, to evaluate the degree of dispersion of the reagent and the mean residence time of the reactor.