Recent Developments of Supercritical Water Oxidation: A Patents Review

Supercritical Water Oxidation is a technique for the complete oxidation of organic wastes, based on the physical properties of water in supercritical conditions: complete miscibility with organics and with oxygen. This technology allows very high efficiency of oxidation to be achieved with very short residence times in the reactor (< 5 min) and a single- step treatment process. However, there are also some limitations for the application of this technology, particularly for the treatment of feeds with high concentrations of salts that can precipitate and clog the equipment, or in the treatment of highly corrosive materials. In this review, several patents are presented which describe inventions for dealing with these difficulties, including new reactor designs, construction materials or operation methods. Additionally, the peculiarities of SCWO treatment can be exploited to develop new processes with economic advantages such as the production of energy or the recovery of precious materials from wastes.