Studies on Magnesium-Based Wet Flue Gas Desulphurization Process with a Spray Scrubber

Abstract

This paper presents a gas-liquid absorption reaction between Mg(OH)₂ slurry and SO₂ for magnesium-based wet flue gas desulphurization (FGD) with a spray scrubber. Experimental investigations on effects of different operating variables show the reasonable process parameters such as the gas flow rate, the SO₂ inlet concentration in the gas, the liquid-gas ratio, the byproduct concentration in the slurry and the pH value of the slurry. An interesting phenomenon is also found under different byproduct concentrations. A desulphurization process model is established by the double-film theory of mass transfer. The calculated mass transfer coefficients are in reasonable agreement with the experimental values and the absorption process is found to be controlled by gas-film diffusion. These results would be useful for the design or process optimization of the magnesium-based wet FGD system.