Limestone dissolution in stack gas desulfurization. A mass‐transfer model is shown to predict the the measured dissolution rates with less than 30% error

Abstract

Limestone slurry scrubbing with production of CaSO/sub 3//CaSO/sub 4/ waste solids is the dominant commercial technology for flue-gas desulfurization. The rate of limestone dissolution directly determines the need for excess limestone and therefore affects the cost of makeup and waste disposal. It also interacts strongly with SO/sub 2/ removal and scale-free operation in the operation in the absorber. A previous paper presented a mass-transfer model and experimental results on the dissolution rate as a function of solution composition. There is also a need to know the dependence of dissolution rate on the particle-size distribution and source of limestone. This paper presents experimental results which show that particle-size distribution is the primary factor determining reactivity of naturally occurring limestones. A mass-transfer model is shown to predict the measured dissolution rates with less than 30% error. 15 references, 8 figures, 3 tables. (JMT)