Partial Oxidation of Phenol in Supercritical Water

Phenol is hardly gasified in supercritical water (SCW) under the temperature 450 °C, at which cleavages of aromatic ring occur difficultly. Partial oxidative gasification provides a potential way to remove phenol for hydrogen at those temperatures. The results showed that even O2 was less than the required amount for complete oxidation by stoichiometry, effective gasification of phenol in SCW was took place. About 76 % of phenol was removed and 2.7 mol/mol of hydrogen was produced with Na2CO3 as catalyst at 180s, O/Phenol 7.5, 450 °C and 24 MPa. The process also indicated partial oxidation of phenol produced some opening-rings products such oxalic and maleic acid, which were slowly gasified. Specifically, at lower O/Phenol ratios, the gasification reaction was predominant which led higher yields of H2, while at higher O/Phenol ratios, the oxdication predominated, which increased the amount of CO2 with less H2.