Investigation on oxidation of o-xylene in liquid phase to prepare o-toluic acid

Preparation of o-toluic acid from o-xylene over cobalt naphthenate catalyst in the presence of air in liquid phase oxidation is presented. Experiments were conducted on a semi-continuous bubble bed reactor, and the effects of reaction conditions, such as temperature, pressure, air flow-rate and reaction time, on the yield of o-toluic acid were evaluated. At a reaction temperature of 130°C, a pressure of 0.25 MPa(g), an air apparent velocity of 0.011 m/s and a reaction time of 5 h, the o-toluic acid yield was 43. 2wt%.