Non-isothermal kinetic modelling of coconut husk pyrolysis using model-fitting and model-free approaches

Increasing interest in thermochemical conversion of agricultural residues is motivated by its promising potential to supply the increasing demand for renewable energy. The kinetics of coconut husk pyrolysis have been studied to determine the suitability of the product in terms of the sustainability of bio-oil production. Proximate and ultimate analysis showed the high content of volatile matter (60.83 %) and carbon (44.30 %) and low ash (10.55 %), which makes it a good energy conversion material. Heating rates of 10, 20 and 30°C/min in thermogravimetric (TGA) and differential thermogravimetric (DTG) analysis revealed three principal thermal degradation stages: loss of moisture, active devolatilization and fragmentation of lignin. The positive activation energies calculated by the Coats-Redfern, Flynn-Wall-Ozawa, and Kissinger-Akahira Sunose kinetic methods confirmed the temperature-dependent nature of the reactions. The study confirmed the feasibility of producing sustainable fuels from coconut husk.