Figure2shows the micrograph images of the three powders with particle size 75–150lm, 150–300lm, and
300–425lm. The particles of palm kernel shells observed
to be of irregular shapes and fibers (shown by the arrows)
were noticeably present in the powder with size ranging
from 300–425 lm as shown in Fig.2c. Figure2d shows
the physical appearance of the pellets produced with different particle sizes. The pellet made with the smallest
particle size had a finer surface appearance and no chipping
was observed. However, the pellet made with the largest
particle size had a coarse surface and some chipping could
be seen. The true densities of the palm kernel shell powders
were (1.42±0.01) g/cm
3
, (1.37 ±0.01) g/cm
3
, and
(1.30 ±0.01) g/cm
3
for the size range of 75–150 lm,
150–300lm, and 300–425lm, respectively. These measured densities are consistent with the average values
reported in the literature [24].