Abstract <p>In this study, biochar was prepared by slow pyrolysis of palm kernel seeds at 350°C for 2 h. Characterization of the raw material (palm kernel seeds) and biochar was carried out by elemental analysis, FTIR, BET and SEM analyses. The results showed that the pyrolysis process transformed the palm kernel seeds, resulting in an increase in the carbon content and decrease in the hydrogen and oxygen contents of the biochar. The transformation was also obvious in the FTIR spectra, with the biochar showing peaks with less intensity than the raw material. The SEM images further confirmed the changes as the oily morphology of the raw material was not observed in the biochar, while the BET analysis showed an increase in the surface area from 3.03 m²/g in the raw material to 45.15 m²/g in the biochar. The results of the solid fuel properties showed that the higher heating value (HHV) increased from 24.04 MJ/kg in the raw material to 27.15 MJ/kg in the biochar, while the energy densification ratio was 1.13 in the biochar. The energy properties of the prepared biochar are consistent with previous studies, indicating that the biochar has the potential for development as solid fuel. Consequently, pyrolysis could be an attractive technique for converting this waste material into high value-added product.</p>