Effect of mineral matter on the reactivity of lignite chars

In this study, the effect of mineral matter on the combustion reactivity of chars produced from 25 lignite samples originating from various parts of Turkey was investigated. Char samples were produced from both original and demineralized lignites. Non-isothermal thermogravimetry has been used to determine the combustion reactivity of the samples. The combustion activation energies were calculated by the Coats-Redfern and Zsako methods from their TG data. Burning profiles of the original and demineralized lignite chars were also compared and discussed. The relationship between the carbon contents of the parent lignites and the conversions of their chars at 1273 K was studied as well. It was observed that the mineral species showed an important effect on the combustion reactivity of the char samples. (C) 2000 Elsevier Science Ltd. All rights reserved.