Collect. Czech. Chem. Commun. 1992, 57, 2315-2320

Influence of the Temperature on Calcium Sulfite Content of the Reaction of SO2 with CaO

K. M. Allal, M. Abbessi and M. Zerdaoui

Institut de Chemie industrielle, Université de Annaba, B.P. 12, El hadjar, Algeria


The purification of the gases containing sulfur oxides such as SO2 and SO3 can be realized by reacting with dry alkaline substances like calcium oxide. At relatively low temperatures (<500 °C) calcium sulfite (CaSO3), an unstable product of the reaction can be formed and may react reversibly to give back SO2. It is therefore important that the reaction be controlled. The influence of the temperature on the amount of calcium sulfite formed has been studied experimentally by means of a thermobalance. The formation of CaSO3 can be avoided if the temperature is higher than 650 °C.