Experimental Performance and Modeling of a New Cooled-Wall Reactor for the Supercritical Water Oxidation

For the commercial application of the supercritical water oxidation (SCWO), new reactors that are able to withstand the harsh operational conditions of the process must be developed. In this work, a new scaled-up design of the cooled-wall reactor (CWR) is presented, which isolates the temperature and pressure stresses caused by SCWO processes. The new reactor consists of a series of chambers designed as a heat exchanger to maximize the residence time and minimize the temperature gradient inside the reactor, allowing a better thermal protection of the pressure shell. This reactor has been implemented in a demonstration scale plant located in the industrial site of a waste management company. Experimental results obtained in this plant with five prototypes of the reactor are presented, explaining the strong and weak points of the designs and the modifications proposed to overcome the operational problems. Experimental results obtained working with oxygen and air as an oxidant and feeds containing isopropyl alcohol and mixtures of isopropyl alcohol/ammonia are thoroughly examined and compared. To have a better understanding of the behavior of the reactor a mathematical model specifically developed for the new reactor is presented.