Abstract:
This present work focused on the characterization of treated oil palm frond (OPF)
from ozonolysis pretreatment. The ozonolysis pretreatment was performed in a
conventional semi-batch reactor at ambient condition. The effectiveness of
ozonolysis pretreatment was validated by investigating the degradation of lignin
and composition of solid product from pretreatment (treated OPF). In addition,
crystallinity, surface area, pore structure, and morphology of untreated and
treated OPF, as well as functional groups present were examined accordingly to
study the effect of ozonolysis pretreatment on physical properties of OPF. The
ozonolysis pretreatment on OPF was found to degrade the lignin structure, and
exerted only a slight effect on the hemicellulose structure. Meanwhile, the
cellulose yield was increased. As comparison to the untreated OPF, the
crystallinity index OPF was increased while the surface area, pore volume, and
mean pore diameter for the treated was decreased. This observation explained
that the ozonolysis reaction has degraded the C=C bond of acid insoluble lignin
into acid soluble lignin. Thus, the lignin could be removed easily by washing with
water. Removing the amorphous component would lead to higher crystallinity
index. Meanwhile, the pore properties of treated OPF would collapse during
washing and drying process. Results of the present study indicated ozonolysis
pretreatment as an effective method for OPF pretreatment to produce a washed
clean substrate rich in cellulose and xylan. In addition, the physical properties of
OPF were improved and ready for subsequent downstream bioconversion
process such as acid hydrolysis for glucose production.
