A master plot approach on rice husk decomposition through pyrolysis and kinetic elucidation using iso-conversional models

The present study aimed at predicting the intricate mechanism followed by the pyrolysis of locally available rice husk, uses noval modified master plots through continuous slope-based differential techniques. An average apparent activation energy was found in the range of 187.29 (KAS model) and 199.85 kJ mol −1 (OFW model), respectively. The rice husk revealed higher volatile matter; 54.51 wt-%, HHV; 18.42 MJ kg −1 and a critical pyrolysis zone around 250 to 550 °C with two sharp peaks through differential thermogravimetric analysis. Using Karl–Pearson correlation, experimental curve showed highest correlation coefficient of 0.94 and 0.75 with respect to A2 and A3 models (Avrami–Erofeev) for g ( α ). However, for Z ( α ), the process is limited by first-order multi-diffusion processes (D1) coupled with solid phase surface reaction (F3) showing correlation coefficient of 0.8. The experimental data worked out the generalized model of f ( α ) as f ( α ) = 12.74 α 3 – 24 α 2 + 12.6 α - 0.92 with R 2 value of 0.99, narrating the usage of master plots for better understanding of the process.