With increasing environmental concerns, much effort has been spent in research regarding development of

sustainable processes for production of fuels and chemical products. In this context, hydrothermal liquefaction (HTL) has gained increasing attention, as a possible route for the chemical transformation of organic raw-materials, some sort

of biomass, for example, into liquid oils at temperatures usually below 400 °C, under moderate to high pressures (5–25MPa), usually in the presence of a suitable catalyst. In the present work the thermogravimetric (TG) behavior under

inert atmosphere of pure green coconut fiber and mixtures thereof with a spinel phase (Fe₂CoO₄), acting as catalyst

has been studied. Spinel samples have been produced at 1,000 °C and different calcination times (3 h, 6 h and 9 h). Both

raw and synthesized materials were characterized through different techniques, such as scanning electron microscopy

(SEM), X-ray diffraction (XRD) and Infrared Absorption Spectroscopy (FTIR). According to the TG data, the catalyst

produced during a calcination time of 9 h showed a superior behavior regarding the lignin full thermal decomposition,

which developed without fixed carbon formation. The results further suggest that the mixing process has a significant

effect over the measured degradation kinetics, as it has a direct influence over the contact between catalyst and fibers.

The kinetic modelling applied to the dynamic TG signal allowed a quantitative representation of the experimental data.

The global process activation energy and order have proven to be respectively, 85.291 kJ/mol and 0.1227.