Development of an integrated model for absorption of sulphur dioxide in limestone slurry

Abstract

The aim of this study is to develop an integrated model for SO2 absorption into limestone slurry consisting of four sub-models, namely, absorption of SO2; desorption of CO2; dissolution of limestone and crystallization of calcium sulphite hemihydrate. The secondary objective of this study is to characterize regimes of SO2 chemical absorption during SO2 absorption into limestone slurry in an agitated vessel over an extended period. The model requires the development of numerical algorithm to solve a set of differential and algebraic equations. Laboratory experiments were conducted under varied experimental conditions, namely, solids concentration, gas concentration and temperature. The principal results are the characterization of regimes and the development and the experimental validation of the integrated model. Model predictions compared well with experimental transient data for concentrations of SO2 in the bulk gas, pH of the bulk slurry and concentrations of Calcium carbonate and Calcium sulphite hemihydrate in the bulk slurry