Kinetics and thermodynamic analysis of palm oil decanter cake and alum sludge combustion for bioenergy production

The main purpose of this research is to explore the thermo-kinetics of the combustion process in-volving palm oil decanter cake (PODC) and alum sludge (AS) for bioenergy production. Thermo-gravimetric analysis (TGA) was utilized for the investigation and analyzing of the combustion characteristics. Coats-Redfern methods was applied to estimate the activation energy (Ea) and pre-exponential factor (lnA) using twelve reaction mechanisms. TGA curve revealed that unlike PODC, AS and blends exhibit two degradation ranges. The mass loss of PODC/AS co-combustion reduced with AS addition. Kinetic study revealed that for range I, 50PODC+50AS has the best re-action rate with models P3 and P4. Ea and lnA for P3 and P4 model are (13.52 kJ/mol and 7.19 min-1) and (11.13 kJ/mol and 6.57 min-1) respectively. Delta H, Delta G, Delta S for P3 and P4 models are (8.4 kJ/mol, 131.15 kJ/mol, -0.2 kJ/mol.K) and (6.02 kJ/mol, 131.96 kJ/mol, -0.21 kJ/ mol.K) respectively. For range II, 50PODC+50AS has the best reaction rate with model A3. The Ea and lnA for A3 model are 41.40 kJ/mol and 12.36 min-1 respectively. Delta H, Delta G, and Delta S for A3 model are 35.16 kJ/mol, 153.84 kJ/mol, and 0.16 kJ/mol.K respectively. Overall, 50PODC+50AS demonstrated the highest reaction rate, suggesting its superior suitability for bioenergy production.