Analysis of relevant steps in wet flue gas desulphurisation processes using limestone slurries

The treatment of flue gases from power plants is required to satisfy the stringent emission limits, particularly in order to reduce the SO₂ emissions into the atmosphere. The processes that have reached industrial scale are the wet limestone and the limestone‐gypsum processes, principally due to the low cost and wide availability of the reagent.

In this paper attention is focused on the SO₂ gas‐liquid transport rate and on the limestone dissolution rate. Experimental runs both on the sulphur dioxide absorption and on the limestone dissolution have been performed at laboratory scale.

The enhancement factor has been evaluated from the absorption experimental results. A model to determine the limestone dissolution rate has been developed, and the experimental results on the limestone dissolution have been compared with model results.

Key words:

• Absorption
• dissolution
• desulphurisation
• limestone
• sulphur dioxide