Offgas, metallurgical sulfur burning

The industrial method of removing H20(g) from sulfur burning air and metallurgical/ spent acid offgas is to pass the air or gas upwards through descending strong sulfuric acid, Fig. 6.3. Dehydration is represented by the reaction ... 

S02 oxidation requires 02. Sulfur burning furnace offgas already contains 02, Table 7.1. None needs to be added. Metallurgical and waste acid decomposition furnace offgases often contain little 02, so some must be added before catalytic S02 oxidation. It is added in air or ventilation gas before gas dehydration. 

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