Effect of initiating additives on phenol oxidation in water-oxygen fluid

Phenol oxidation in a water-oxygen fluid in a tubular batch reactor with its uniform heating (1 degrees C/min) to 600 degrees C was studied. An increase in the amount of O2 above the stoichiometric ratio by 25 % leads to an increase in the degree of carbon burnout by the factor of 1.09. Replacing 10 % of the stoichiometric amount of oxygen with nitrous oxide leads to the same increase in the degree of carbon burnout, primarily due to its afterburning at a temperature of >= 400 degrees C. Replacement of some part of phenol with isopropanol leads to an increase in the degree of carbon burnout by the factor of 1.02. It was established for the first time that the heterogeneous mechanism of phenol oxidation in a water-oxygen fluid is the main one. However, the overstoichiometric amount of O2, as well as the addition of N2O and isopropanol intensifies gas-phase combustion of carbon. A catalytic effect of a Pt-Rh/Pt-thermocouple on the degree of phenol conversion in the presence of O2 at temperatures above 135 degrees C was found.