Catalytic oxidation in supercritical water

Recently, catalytic oxidation in supercritical water (SCW) has received considerable research attention. The major thrust of this current research effort is attributable to the rapid development of supercritical water oxidation (SCWO) as an innovative wastewater treatment technology. The incentives of catalyst-enhanced processes may include increased reaction rates, reduced residence times and temperatures, and optimized reaction pathways that are otherwise difficult to achieve through noncatalytic processes. However, the databases associated with the use of catalysts in SCWO are limited. The purpose of this paper is to (1) review catalytic enhancement and technology as related to SCWO; (2) analyze effects of SCW on catalysts and catalytic SCWO processes; and (3) present a catalyst development strategy for SCWO-related applications. Catalyst activity and stability (in terms of reaction kinetics, surface phenomena, and phase behavior of catalysts in SCW) are emphasized. The paper presents a useful database, provides guidelines for catalyst selection, and illustrates how effective use of catalyst may enhance SCWO process development.