KINETICS OF WET OXIDATION OF P-COUMARIC ACID OVER A CUO.ZNO-AL2O3 CATALYST

The semi-batch wet oxidation of p-coumaric acid, a biorecalcitrant pol yphenolic compound typically found in olive processing and wine-distil lery wastewaters, using a CuO.ZnO-Al2O3 catalyst in slurry form at tem peratures from 373 K to 403 K, oxygen partial pressures from 2.3 to 32 .3 bar, catalyst concentrations from 0.088 to 4.4 g l(-1) and particle size from 38-250 mu m, has been investigated. The catalyst was found to be capable of increasing the rate of p-coumaric acid oxidation by a s much as 20 times that of the uncatalysed reaction, at 403 K. The rat e of p-coumaric acid oxidation was found to be first order with respec t to its concentration and proportional to oxygen partial pressure to the power of 0.65 over the range of operating conditions where oxygen partial pressure exerts a significant effect (2.3 to 17.3 bar). With t he particle sizes used, there were no intraparticle diffusional limita tions.