Kinetics of Supercritical Water Oxidation of Methanol Studied in a CSTR by Means of Raman Spectroscopy

A newly devised continuous flow stirred tank reactor (CSTR) was employed for the study of kinetics of supercritical water oxidation (SCWO) of methanol near the critical point (390−430 °C, 24.7 MPa), where the reaction progress was analyzed by means of Raman spectroscopy. The production of CH2O, CO, and CO2 through the oxidation reaction was directly detected. Methanol conversion as a function of residence time could be analyzed on the basis of a simple first-order CSTR reaction model including phenomenological induction time. The overall reaction rate thus obtained was well-reproduced through simulation by a detailed chemical kinetics model, which supports the belief that the radical chain reaction mechanism is responsible for methanol SCWO even near the critical point.