AbstractNon‐isothermal thermogravimetric tests of Terminalia chebula (Helikha) were conducted under inert N2 gas environment for temperatures (25–900°C) at heating rates of 10, 20, 35, and 55°C min−1. Kinetic triplet approximated employing five iso‐conversional methods namely, differential Friedman method (DFM), distributed activation method (DAEM), Ozawa–Flynn–Wall (OFW), Kissinger–Akahira–Sunose (KAS), and Starink (STK). Average values of activation energy (kJ mol−1) and frequency factor (min−1) calculated by the five models were 227.11, 2.98 × 1021 for DFM; 229.21, 4.63 × 1021 for KAS; 227.11, 3.81 × 1020 for OFW; 225.54, 1.15 × 1018 for STK; and 227.33, 3.02 × 1020 for DAEM respectively over the conversion range up to 0.8. In the kinetics study, correlation coefficient (R2) of greater than 0.97 is noticed in the conversion range of α = 0.1–0.8 for all models. From thermodynamic analysis, average values of ΔH (kJ mol−1), ΔG (kJ mol−1), and ΔS (kJ mol−1 K−1) for DAEM: 221.8, 179.69, and 0.065; for DFM: 236.40, 179.37, and 0.089; for KAS: 221.8, 179.69, and 0.065; for OFW: 220.22, 179.72, and 0.063; and for STK: 222.02, 179.68, and 0.066 were estimated to assess viability and reactivity of the process. Criado's master plots revealed that the data obtained from pyrolysis of selected biomass was followed a multistep reaction pathway.
Read full abstract