Sweet sorghum bagasse represents a potential
low-cost biomass which can be valorized to produce different
value-added lignocellulosic platform chemicals of
economic importance. The focus of the present study is the
pretreatment of sweet sorghum bagasse for efficient delignification,
separation of pure cellulose and its structural
characterization. Sweet sorghum bagasse was subjected to
mechanical commutation followed by steam washing,
organosolv extraction (methanol and toluene, 1:2) and
alkaline hydrogen peroxide treatment for efficient delignification.
Chemical analysis revealed that cellulose,
hemicellulose and lignin content (per cent recovered) after
different pretreatment was 720 g (98 %), 6 g (1.1 %) and
20 g (0.9 %), respectively. Structural characterization of
untreated sweet sorghum bagasse and recovered cellulose
was performed using FT-IR, CP-MAS 13C NMR spectroscopy,
XRD, and thermogravimetric analyses. The cellulose
preparation obtained after chemical pretreatments
had typical cellulose structure with high crystallinity as
compared to the untreated substrate. SEM micrographs
revealed the surface topography wherein the waxy layer on
the surface of this material disappeared and the texture
became thinner and striated. The pretreatment methods
employed were able to produce cellulose of high purity
with[98 % lignin removal.