Studies on Sulfur Oxides Removal from Flue Gas by Dry Limestone Injection Process (IV)

Abstract

As descrided in the previous paper, the reaction rates of sulfur oxide with calcium oxide partices in combustion gas were varied with various reaction conditions. The effects of the reaction conditions were discussed in this paper at the view point of the characteristics on the decreasing tendencies of the reaction rates along with the progresses of the reactions.Their results sre concluded as follows.(1) Somewhat higher reaction rates were odtained at the deginning of the reactions when the limestone was injected into combustion gases but the decrease of the reaction rates were more rapid with the progresses of the reactions.(2) The reason that the Tokunoshima limestone had highest calcium oxide utilization is caused dy the more slight decrease of the reaction rate compared with the other limestones.(3) The activity of the calcium oxide for the reaction with sulfur dioxide may de depended on the surfaca area and the deffect of the calcium oxide lattice.(4) The surface area of limestone particles are considered to be the sum of the particles. The increase of the surface area by calcination means the increase of internal surface area of the panicles. The internal surface area of the particles decreases with the progress of the reaction with sulfur dioxide. The higher decreasing tendencied are obtained with decreasing the particle size of calcium oxide.