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 studied in four laboratories, using catalysts EL10V1 and EL10V8; conversions and product yields as a function of time-on-stream are reported. The results obtained are in generally good agreement: for both catalysts, 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 performance. Differences in the temperatures required to attain a fixed conversion may reflect differences in reactor design, especially with regard to heat exchange efficiency.