Simulation of spray dryer absorber for removal of SO₂₊ from flue gases

The focus of the present activity is the development of a mechanistically based mathematical model of sulfur dioxide removal in a pilot plant scale spray dryer.

In the spray dryer, flue gas from a coal burning boiler is contacted with an atomized lime slurry. During this contact sulfur dioxide absorbs and reacts with calcium hydroxide. The developed mathematical model superimposes the sulfur dioxide absorption and reaction phenomena on existing mathematical descriptions of spray dryer operation. Using established spray dryer terminology, the sulfur dioxide removal processes occur in the constant and falling rate periods.

Efficiency predictions using the model presented here were compared with data from the pilot plant taken at different inlet flue gas temperatures, stoichiometric ratios, slurry flow rates, and droplet sizes. This comparison shows a good agreement with the individual data points and with overall trends in the data.