Removing sulphur oxides from waste flue gas - using activated, alkali-free aluminium which can be repeatedly regenerated

摘要

The absorption occurs at 100-400 degrees C to form sulphates on the absorbent. The absorbent is then heated to 250-450 degrees C with a redn. gas, esp. gases contg. H2S, to produce elementary sulphur which is sepd. from the absorbent. The absorbent is then re-used. The Al pref. has a specific surface above 50 m2/g, esp. between 150-500 m2/g; for fluidised beds the Al has size 50-100 mu m, and for solids beds 0.5-10 mm. The Al may contain numerous other elements, esp. Fe and Ti arising from bauxite. In an example, waste gas from a 125 MW power station contg. 2000 ppm. So2 is treated to reduce SO2 concn. to 212 ppm.