Effect of coal particle density on combustion kinetics of Indian coal

ABSTRACT

This work presents the combustion behavior of different mean relative densities (MRD) of Indian thermal coal. Coal of different MRD in the range of 1.25 to 2.20 was prepared using the density separation method. Essential characterization of all MRD fraction coals was done by proximate analysis, ultimate analysis, gross calorific value, BET analysis, and ash analysis. The combustion behavior of all coal samples was carried out by a thermogravimetric analyzer (TGA). Combustion characteristics parameters such as ignition temperature (T_IG), peak temperature (T_max), burnout temperature (T_BT) and maximum combustion rate (DTG_max) were evaluated using TGA-DTG data. Results show that with the increase of MRD from 1.25 to 2.20, T_IG and T_max increase from 324°C and 451°C to 426°C and 462°C, respectively, while DTG_max reduces from 9.52 to 1.68 mass%/min. The kinetic analysis demonstrates that coal combustion follows the first-order reaction model and can be separated into two stages. The thermodynamic parameters signify that lighter MRD coal requires lower endothermic energy than heavier MRD coal.

KEYWORDS:

• Mean relative density
• coal
• combustion
• kinetic study
• thermodynamic analysis

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.