Use of Progressively Improved Catalysts

Vanadium pentoxide based with potassium/sodium compounds as promoters. .. both SCSA and DCDA process 

The equilibrium conversion of SO2 to SO3 is higher at lower temperatures while the catalyst had an ignition temperature of at least 400-405 C practical operation. The earlier catalysts were able to achieve a maximum conversion of SO2 up to 99.5-99.6%. 

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