Thermogravimetric study of the pyrolysis characteristics and kinetics of coal blends with corn and sugarcane residues
Résumé
This paper investigates the non-isothermal thermokinetics of the co-pyrolysis of sugarcane bagasse and corn
residue blended with coal. The individual devolatilization behaviour of each of the fuels obtained separately
was compared with the behaviour of the biomass blends with coal at various mix ratios. Possible synergistic
behaviour that points to the existence of chemical interactions during pyrolysis between the coal and biomass
fractions of the blends could thus be quantified. Synergistic interactions in the blends resulted in higher
than expected volatile yields. The interactions occurred between 300 °C and 500 °C, corresponding to the end
of biomass devolatilization and the start of coal decomposition. Isoconversional kinetic analysis revealed that
apparent activation energy values varied between 165–180, 162–190, 160–175, and 225–260 kJ mol−1 for
sugarcane bagasse, corn cobs, corn stover, and coal in the 0.1 to 0.8 conversion range. A comparison of
E(α) for single fuels and coal-biomass blends gave further evidence of synergistic behaviour as demonstrated
by larger variation in E(α) during the decomposition of the blends, compared to the individual fuels.