Use of supercritical water (SCW) as a medium for oxidation reactions, conversion of organic
materials to gaseous or liquid products, and for organic and inorganic synthesis processes, has been
the subject of extensive research, development, and some commercial activity for over 25 years. A key
aspect of the technology concerns the identification of materials, component designs, and operating
techniques suitable for handling the moderately high temperatures and pressures and aggressive
environments present in many SCW processes. Depending upon the particular application, or upon the
particular location within a single process, the SCW process environment may be oxidizing, reducing,
acidic, basic, nonionic, or highly ionic. Thus, it is difficult to find any one material or design that can
withstand the effects of all feed types under all conditions. Nevertheless, several approaches have
been developed to allow successful continuous processing with sufficient corrosion resistance for an
acceptable period of time. The present paper reviews the experience to date for methods of corrosion
control in the two most prevalent SCW processing applications: supercritical water oxidation (SCWO)
and supercritical water gasification (SCWG).