This study reports on the pathways and kinetics of individual gaseous species involved in the partial oxidation of phenol in supercritical water. The pathway is a combination of supercritical water oxidation (SCWO) and supercritical water gasification (SCWG) processes. A kinetic model that involves oxygen is proposed that fits the experimental data and accurately predicts the effects of the O/phenol ratio on the decomposition of phenol. Specifically, at lower O/Phenol ratios, the gasification of acids and the water gas shift reaction predominated, increasing the amount of H(2) in the gaseous products. At higher O/Phenol ratios, on the other hand, the oxidation of acid intermediates and CO oxidation predominated, thereby increasing the amount of CO(2), while H(2) decreased. (C) 2011 Published by Elsevier B.V.