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 th e reaction media on a technical scale. To overcome this situation a no vel reactor concept, SUWOX, based on well known materials has been dev eloped in which the reactor resists the attack of hydrochloric acid un der SCWO conditions. The facility is equipped with a 'floating type' a cid-resistant reactor within a pressure vessel. Two coaxial streams ar e established inside the vessel: a corrosive central stream of halogen ated hydrocarbons, oxygen and water inside an alumina reactor where th e SCWO destruction takes place, and an inert annular stream of pure wa ter between the inner wall of the pressure vessel and the external wal l of the alumina reactor. A cumulative operation time of more than 100 0 h has been attained in which the industrial solvent dichloromethane has been destructed. At residence times between 22 and 224 s, temperat ures between 420 and 460 degrees C, and at a constant system pressure of 400 bar destruction rates of dichloromethane of >99.99% have been m easured. (C) 1998 Elsevier Science B.V.