A comprehensive kinetics study of coconut shell waste pyrolysis

Model-free and model-fitting methodswere compared for pyrolytic conversion of the coconut shell waste. The apparent activation energy, estimated from differential and integral iso-conversional methods, increased with the progression of pyrolytic conversion. The reaction model, f (alpha) = (1-alpha)(4) . [-ln(1-alpha)](0.53), indicate that order-based nucleation and growth mechanisms control the solid-state pyrolysis of the coconut shell waste. The active pyrolysis zone was consisted of overlapping multicomponent degradation peaks. Average activation energy of the pseudo-components estimated from the Kissinger's method were 21.9 kJ. mol (1), 106.4 kJ. mol (1) and 108.6 kJ. mol (1) for the dehydration, the degradation of pseudo-cellulose and pseudo-hemicellulose, respectively. Pseudo-lignin decomposed over a wide range of temperature with a slower conversion rate as compared to pseudo-hemicellulose and pseudo-cellulose. Average activation energy range of pseudo-lignin was estimated from the combination of model-free and model-fitting methods as 79.1-226.5 kJ. mol (1). (C) 2017 Elsevier Ltd. All rights reserved.