Low power static-heating start-up procedure for supercritical water oxidation plants

Abstract

One of the factors against the upscaling of SCW plants is the enormous amount of energy demanded during the start-up phase to reach the stationary state and the autothermic operation phase. This work proposes a new strategy with a lower energy cost and, consequently, with a smaller initial investment. It consists on statically heating up different sections in an SCWO plant by means of electric heaters distributed throughout the plant. A constant temperature of 400 °C can be reached in a plant containing a mixture of water and ethanol at near critical pressure. Then, when the feed and the oxidant are pumped, the oxidation reactions starts. Such reaction, in turn, releases the heat required for autothermal operation. The experiments that have been carried out have confirmed that the Low Power Static-heating Start-up Procedure (LPSSP) proposed would mean a saving of 46.4% in power consumption when compared to a conventional startup procedure.