Thermal and kinetic study of rice husk, corn cobs, peanut crust and Khushab coal under inert (N2) and oxidative (dry air) atmospheres

Abstract

The objective of this research was to investigate the thermal characteristics and thermochemical process kinetics of the agricultural residues and coal under inert and oxidative atmospheres. Non-isothermal thermogravimetry technique was used at different heating rates of 10, 20 and 30 °C min−1 under both atmospheres. Total weight loss (%) in the major degradation stage, average rate of weight loss, maximum rate of weight loss and peak temperature were evaluated. In pyrolysis and combustion reactivity based on peak temperature ranking at 10 °C min−1, 20 °C min−1 and 30 °C min−1 were found to be; CCO < PC < RH < K coal, RH < CCO < PC < K coal and PC < CCO < RH < Kcoal under inert atmosphere and PC < RH < CCO < K coal, PC < CCO < RH < K coal and RH < PC < CCO < Kcoal under air atmosphere. The activation energy (Ea) for RH, CCO, PC, K coal in inert and oxidative atmospheres found at 10, 20, 30 °C min−1 116-86, 126-109, 113-97, 107-47 kJ/mol and 151-111, 205-89, 124-100, 58-54 kJ/mol using Arrhenius model. Coats-Redfern model exhibited lower Ea values than Arrhenius model at same heating rate and reaction atmospheres; 103-69, 133-80, 95-71, 78-26 kJ/mol and 118-75, 142-80, 109-75, 94-70 kJ/mol.