Abstract:
This study was aimed to select a cost-effective pretreatment for aggressive
colonizer Parthenium hysterophorus in order to utilize the lignocellulosic biomass
for the production of cellulosic bioethanol. Deploying diverse pretreatment methods
will enable to choose the efficient and economical path to cellulose recovery from the
biomass. Pretreatment is necessary to expose the carbohydrate polymers buried in
the interior of the cell wall and make them accessible to the hydrolytic enzymes dur-
ing saccharification to yield appreciable levels of fermentable sugars subsequently
producing ethanol. Dried ground powder of Parthenium hysterophorus biomass was
subjected to fifteen different chemical (NaOH, H 2 SO4 , Chlorocholine- oxalic acid,
Performic acid, H 2 O 2 ) and physical (autoclaving, microwave, dry heat in furnace,
boiling) treatments of different combinations. The dry weight of cellulose and lignin
was calculated for all the treated samples using gravimetric methods. This was further
confirmed by subjecting the pretreated samples to Fourier Transform InfraRed Spec-
troscopy (FTIR) to examine the functional groups of the polysaccharide. Acid treat-
ment (0.1-1.0% H2 SO 4 ) at 200°C provided comparatively higher cellulose yield, but
it removed lignin less effectively than NaOH treatment. Microwave assisted NaOH
and boiling with NaOH were found more effective than NaOH at room temperature.
Based on the gravimetric estimation and FTIR analysis, boiling at 2% NaOH treated
sample for 20 minutes, autoclaving at 2% NaOH treated sample for 20 minutes with
sudden pressure release and microwave assisted 2% NaOH treatment at 280 W for
three minutes were among the effective pretreatment methods of biomass investi-
gated.
