SELECTIVE OXIDATION OF O-XYLENE TO PHTHALIC-ANHYDRIDE OVER THE EUROCAT V2O5 TIO2 CATALYSTS/

The selective oxidation of o-xylene to phthalic anhydride has been stu died in four laboratories, using catalysts EL10V1 and EL10V8; conversi ons and product yields as a function of time-on-stream are reported. T he results obtained are in generally good agreement: for both catalyst s, phthalic anhydride yields at 40% conversion are ca. 20%, rising to 63-70% at 100% conversion. Increasing the vanadium content from 1 to 8 % has little effect and may even result in a slightly worse performanc e. Differences in the temperatures required to attain a fixed conversi on may reflect differences in reactor design, especially with regard t o heat exchange efficiency.