Modeling and optimization of phenol hydrothermal oxidation in supercritical water

Abstract

The hydrothermal oxidation is an efficient and clean way for wastewater treatment; it is also an energy self sufficient process under certain conditions, by the mean of the highly exothermic reaction of oxidation.In this present work, we studied the modeling of hydrothermal oxidation of phenol in polluted water using supercritical conditions. First we apply a simple mathematical model for tubular reactor, resulting from mass, momentum and energy balances, which is often difficult to solve in its general form. According to adequate simplifications, the profiles of temperature and concentration of chemical species are computed along the reactor. Finite differences numerical method was used to solve the obtained system of equations and a MathCAD program was developed for this purpose. The results are close to experimental works from the literature.To study the influence of some operating conditions on the efficiency of the treatment and the amount of heat generated by the reaction and which will be recovered to heat the inlet flows, we exploited the modeling results to perform a full factorial design of experiment (DOE). The results allow fixing the optimal conditions for the studied factors on the efficiency and energy recovery of the process treatment.