Kinetic Study of Calcination of Jakura Limestone Using Power Rate Law Model

Abstract

The current demand of hydrated lime [Ca(OH)2] worldwide has necessitated investigation into kinetics of calcinations of some large commercial deposits of limestone in Nigeria. The study is aimed at finding kinetic parameters for the purpose of energy saving, lime kiln design, modeling and simulation of lime kiln. In this study, kinetic of Jakura limestone calcination process
using power rate law has been investigated. The Jakura limestone has percentage composition of 96.56% of Calcium Carbonate (CaCO3) and the results of its decomposition at different temperature between 800 – 12000C showed that conversion of CaCO3 to quicklime (CaO) increased with increase
in reaction temperature and reaction time. It was observed that optimum conversion time within the temperature range studied was 6 hours with maximum conversion of 91.01% achieved at 12000C. The calcination of Jakura limestone was also found to be first order reaction with respect to CaCO3 concentration having average regression coefficient of 0.99. The temperature dependent terms were found using Arrhenius law and it was observed that the reaction temperature has a direct effect on the rate of reaction. The effective values of activation energy and frequency factor were all within the range of literature values and were found to be 121.708kJ/mol/K, and 2.943 respectively.