IMPORTANT CONCEPTS OF WET-LIMESTONE FLUE GAS DESULFURIZATION

Many utilities are installing wet flue gas desulfurization (FGD) systems to comply with tighter sulfur dioxide regulations. These installations will introduce many utility engineers and other technical personnel to a sometimes complex air pollution control technology. This paper outlines fundamental concepts of wet limestone FGD, particularly in the most common design, spray towers. Topics will include liquid-to-gas ratio, chemistry operating parameters, limestone grinding and classification, materials selection for a rugged environment, byproduct disposal, and scrubber performance monitoring. The paper will also briefly review cutting-edge alternatives to spray towers.