Effect of additives on limestone reactivity in flue gas desulfurization

ABSTRACTIn this article, the influence of temperature, stirring speed, limestone type, particle size, and desulfurization additives on the limestone dissolution rate was investigated. The dissolution reaction was modeled by shrinking-core model. As the temperature increases, the dissolution reaction rate increased rapidly, and the activation energy was 25.76 kJ/mol. The relation between reaction rate constant and stirring speed was obtained to be k = 0.0205·ω°.511. When the CaCO3 content of limestone was higher, the improving effect of reducing particle size on dissolution rate will be more significant. Sulfates were found to inhibit the limestone dissolution, while magnesium salts were found to improve the dissolution.