Energy Sources Part A-recovery Utilization and Environmental Effects, Vol.40, No.20, 2458-2466, 2018
Combustion behavior of KOH desulphurized coals assessed by TGA-DTG
This work presents the results obtained from the experimental study on the effects of KOH treatment and its combustion behavior of high sulfur Indian coal. Coal was treated with 5-20% KOH (v/v) concentration for 6-24 h reaction time to identify the effects of KOH treatment on coal properties. Experimental results showed that upto 36.79% of total sulfur can be removed from coal with 20% KOH concentration and 24h contact time at atmospheric condition. However, gross calorific valueof coal decreased from 6800 to 6084kcal/kg due to removal of combustibles from coal. Combustion characteristics of treated coal were assessed by Thermo-gravimetric analysis/ Differential thermo-gravimetric (TGA/DTG analysis). Further various combustion kinetic parameters like ignition temperature, peak temperature, burnout temperature, activation energy (E), and pre-exponential factor (A) are estimated. Experimental results show that the ignition temperature of coal decreased from 321 degrees C to 252 degrees C, peak temperature decreased from459 degrees C to 409 degrees C due to changes in the coal matrix after desulfurization. The activation energy of coal calculated decreased from 79to 45kJ/mol due to desulfurization using 20% KOH concentration and 24h reaction time.