Assessment of agro-industrial residues for bioenergy potential by investigating thermo-kinetic behavior in a slow pyrolysis process

Agro-industrial residue is widely considered as a rich source of energy, with varying characteristics depending on the geographical region or origin from where it is collected. Rice husk, bagasse, corncob, wheat straw and wood chips do not find many applications in Pakistan. As they are available in large quantities and at lower cost, therefore it makes them a favorable candidate for bioenergy. In this study, five agro-industrial residues, of Pakistani origin, were thermally degraded in the absence of air and at a constant heating rate of 5 °C min−1. Kinetics of the pyrolysis process was performed using Coats-Redfern method at five reaction mechanisms. Corncob was found to degrade at lower temperature with fastest rate as compared to all the other wastes. The kinetic parameters obtained from Coats-Redfern method were used to evaluate the thermodynamic behavior of these wastes and afterwards a comparison was drawn. Based on the ascending order of the activation energy, the residues can be classified in terms of preference as corncob > rice husk > wood chips > wheat straw > bagasse.