Thermal behavior and kinetics of pyrolysis of areca nut husk

Abstract

ABSTRACTPyrolysis of agricultural crop residues is making rapid strides in the overall lignocellulosic biomass utilization for the recovery of energy. In the present work, physicochemical properties of areca nut husk such as proximate and ultimate analysis, lignocellulosic composition, and thermal analysis have been carried out. Pyrolysis of areca nut husk was studied using thermogravimetric analysis to determine the kinetic parameters at five different heating rates, viz. 2, 5, 10, 15, 20°C/min. The major mass loss (44.4 wt%) of AH was found to be in the temperature range of 220–370ºC. The kinetic parameters pertaining to pyrolysis of areca nut husk were calculated using distributed activation energy model (DAEM) and model-free isoconversional Flynn-Wall-Ozawa (FWO) method. Miura and Maki integral method was employed to estimate f(E) and k0(E) in this study. The peak of f(E) curve for the areca nut husk was obtained at 240 kJ/mol and the frequency factor (k0) increased from an order of 1013–1022 min−1, while the activation energy ranged from 87.5 to 514.08 kJ/mol. The variation in activation energy values with progressing conversion indicates the existence of a complex multi-step mechanism that occurs during the thermal decomposition of AH. The average activation energy obtained by FWO method was 230.707 kJ/mol (with a range of 62.35–591.972 kJ/mol) which is close to 240 kJ/mol obtained via DAEM method from f(E) curve and hence the results can be said to be reliable and predictive.