Hydrothermal decomposition of thiodiglycol in supercritical water

The hydrothermal decomposition of thiodiglycol in supercritical water is examined. Experiments were performed in an isothermal, plug-flow reactor at temperatures from 425 to 525°C, pressures from 22 to 30 MPa, and reactor residence time from 0.6 to 63.2 s. The thiodiglycol degraded very rapidly at these supercritical conditions. The products include methane, carbon monoxide, carbon dioxide, ethylene, hydrogen, ethanol, acetaldehyde, hydrogen sulfide and sulfur. Increasing residence time, temperature and pressure increased the thiodiglycol conversion. Analysis of the reaction network indicates that the thiodiglycol decomposition in supercritical water occurs through two parallel pathways, hydrolysis and pyrolysis.