was obtained maximum at 45.8 wt% for the particles of
1.7 < dp < 2 mm. The smallest (0.5 < dp < 0.71 mm) particle
size only produced an oil yield of 27 wt% with a char yield of
38.1 wt%. Based on these results particle size is having
a significant influence with the yield of char [26]. If the particle
size was sufficiently small it can be heated uniformly, as is
consistent with earlier studies [27e29]. This result suggested
that mass- and heat-transfer restrictions had a profound
influence at a larger particle size, resulting in maximum oil
yield. Working at a particle size range of 1.7 < dp < 2 mm
seems suitable for obtaining a high yield of liquid product in
fast pyrolysis of palm shell.