Kinetics study of total organic carbon destruction during supercritical water gasification of glucose

The kinetics of total organic carbon (TOC) destruction during supercritical water gasification (SCWG) of glucose were studied at 400-500 degrees C and 25 MPa in a 600 mL batch reactor. Both TOC and water concentrations are critical for the conversion of TOC in supercritical water, especially at longer residence times. Initially, it was assumed that the TOC destruction reaction followed first-order kinetics ignoring the water concentration. However, experimental results showed that the feed-to-water ratio had a significant effect on TOC decomposition. Considering the water concentration in the reaction, the reaction orders of TOC (2.35) and water (1.45) were calculated using nonlinear regression analysis (the Runge-Kutta method). The estimated pre-exponential factor (k') and activation energy (E) were calculated to be 8.1 +/- 2/min and 90.37 +/- 9.38 kJ/mol respectively.