Comparative study on pyrolysis characteristics and kinetics of Indian almond fruit and Gracilaria changii seaweed by thermogravimetric analysis

In this study, the pyrolysis characteristics and kinetic analysis of waste Indian almond fruit (IAF) and the algae Gracilaria changii (G. changii) biomass were investigated using a thermogravimetric analysis (TGA) for the potential source of bioenergy. Four kinetic model techniques as Kissinger, Friedman, Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) were used to evaluate the kinetic characteristics at three different heating rates of 10, 20 and 30 degrees C/min. The thermal degradation of the IAF and G. changii may be classified into three phases, according to TG/DTG data (phase I: 25 to 170 (?)degrees C, phase II: 170 to 480 degrees C and phase III: 480 to 700 degrees C). The activation energies obtained by the Kissinger model, KAS model, FWO model and Friedman model are 67.55 kJ/mol (IAF) and 191.42 kJ/mol (G. changii), 61.81 kJ/mol (IAF) and 189.67 kJ/mol (G. changii), 69.34 kJ/mol (IAF) and 171.67 kJ/mol (G. changii) and 29.56 kJ/mol (IAF) and 153.03 kJ/mol (G. changii) respectively. There is good agreement between the estimated kinetic parameters and the interval conversional fraction. The kinetic research results can be used to simulate devolatilization and generate new business models for the thermochemical conversion process. Due to the negative value of Delta G, predictions of the thermal stability and decomposition of the biomass levels are also estimated. Change in enthalpy, entropy and Gibbs free energy determined was in good agreement for all four kinetic models. This study found that the ultimate utilisation of Gracilaria changii (G. changii) biomass was greater in the synthesis of biofuel than IAF and some other agricultural biomass.

Automated summary

In this study, the pyrolysis characteristics and kinetic analysis of waste Indian almond fruit (IAF) and the algae Gracilaria changii (G. changii) biomass were investigated. The results showed that the ultimate utilisation of G. changii biomass was greater in the synthesis of biofuel.