SUWOX - a facility for the destruction of chlorinated hydrocarbons

The supercritical water oxidation (SCWO) process is a promising method for the destruction of halogenated hydrocarbons. However, no suitable materials have been found yet to withstand the corrosive nature of the reaction media on a technical scale. To overcome this situation a novel reactor concept, SUWOX, based on well known materials has been developed in which the reactor resists the attack of hydrochloric acid under SCWO conditions. The facility is equipped with a 'floating type' acid-resistant reactor within a pressure vessel. Two coaxial streams are established inside the vessel: a corrosive central stream of halogenated hydrocarbons, oxygen and water inside an alumina reactor where the SCWO destruction takes place, and an inert annular stream of pure water between the inner wall of the pressure vessel and the external wall of the alumina reactor. A cumulative operation time of more than 1000 h has been attained in which the industrial solvent dichloromethane has been destructed. At residence times between 22 and 224 s, temperatures between 420 and 460 degrees C, and at a constant system pressure of 400 bar destruction rates of dichloromethane of >99.99% have been measured. (C) 1998 Elsevier Science B.V.