Comprehensive kinetic study of sulfur dioxide removal by magnesium oxide using TG

Abstract

In the present work, an extensive kinetic study of magnesium oxide (MgO) reaction with sulfur dioxide was investigated by isothermal TG. The MgO reaction with sulfur dioxide as a non-catalytic gas–solid reaction was modeled by random pore model (RPM). The tests were conducted at the temperature range between 500 and 700 °C, and the SO2 concentration was in the range of 0.24 to 1.32 vol.%. The rate constants and the relationship between reaction rate and concentration were attained, using the initial slopes method. The reaction was found to be approximately first order with respect to gaseous reactant, and the activation energy was estimated as 37.5 kJ mol−1. Furthermore, appropriate values of diffusion coefficient through magnesium sulfate product layer were calculated. The conversion against time curves were predicted by the RPM, and the model was able to predict the experimental results at various operating conditions with a considerable degree of accuracy.