Three bio-fuels with or without additives and their fly ash samples were characterized using simultaneous Thermogravimetry-Differential
Thermal Analysis-Fourier Transform Infrared Spectrometry-Mass Spectrometry (TG-DTA-FTIR-MS), X-ray Diffraction (XRD), X-ray
Fluorescence (XRF), and Scanning Electron Microscopy-Energy Dispersive Spectrometry (SEM-EDS). The results show that the additives
increase the reactivity of the bio-fuel during combustion. The additives also significantly decrease the amount of unburned
carbon in the fly ash. The additives affect the compounds formed in the fly ash sample, and consequently the thermal behaviour
of the fly ash. The fly ash samples are thermally stable in air up to 100C. The fly ash samples contain fine particles with
irregular shape, small round particles, and large hollow spherical particles with entrapped gases.