Statistical modelling and optimization of alkaline peroxide oxidation pretreatment process on rice husk
cellulosic biomass to enhance enzymatic convertibility and fermentation to ethanol
The complex and ordered arrangements of the lignocellulosic materials make them recalcitrant for their
conversions to ethanol. Pretreatment is a crucial step in overcoming these hindrances. In this study, a
23‐full factorial design of experiments optimization technique was applied on the alkaline peroxide
oxidation pretreatments of rice husks biomass. The low–high levels of the influencing variables on
pretreatments were; temperature (100–120 °C), time (1–2 h), % (v/v)H2O2 concentration (1–3%). Under
the prevailing pretreatments, the optimum conditions were predicted and validated to be 109 °C, 2 h,
and 1.38% H2O2 which yielded 56% (w/w) cellulose content, 55% (w/w) hemicellulose solubilization,
and 48% (w/w) lignin removal. At the established optimum pretreatment conditions, and considering
variations in biomass and enzymes loadings, maximum reducing sugars production was 205 mg/g dry
biomass at different enzymatic hydrolysis conditions of 3% biomass loading, hydrolysis temperature of
45 °C, hydrolysis time of 24 h, and 35 FPU/g cellulose enzyme loading. The highest cellulose conversion
of 33% yielded 24 g/L ethanol at the end of the first day of saccharification and fermentation. Physical,
structural, and morphological investigations on raw and treated materials using tools such as
stereomicroscopy, scanning electron microscopy, and fourier transform infrared spectroscopy further
revealed the effectiveness of chosen method on rice husks biomass
