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Abstracto-Xylene oxidation in a non-isothermal fluidized bed has been studied. Phthalic anhydride yield appears to be significantly higher than in an isothermal fluidized bed or in ideal mixing and plug flow reactors. A higher yield is caused by an unsteady state of the catalyst resulting from a chaotic particle movement in the temperature field.

030ChemInform Abstract V2O5-K2S2O7 and V2O5-Na2S2O7 melts have been investigated over a wide range of vanadium concentrations using 51V, 17O, and 23Na NMR. Coordination of V(V) with 2 or 3 S2O72-anions takes place in the melt. At vanadium concentrations above 1.5 mol l-1, associated complexes are formed which are most active in SO2 oxidation. The SO2-V interaction results in the formation of catalytically inactive, tetracoordinated surface complexes, which form active species upon interaction with monomeric V-S2O72-complexes in the melt.

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