الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
According to the Annual Report of Waste Management statistics in Egypt, issued
2013, Egypt has generated a total of 89.03 million tons of solid wastes.
Agricultural wastes are widely available in Egypt and produced at an annual rate of
more than 46.7 million tons /year . These wastes can be used normally as animal
feed and/or fertilizers. Nevertheless, the majority of this value-added waste is left to
be rot or burned in the open air after harvesting. Thus, utilization of this waste,
which is a form of biomass, for industrial purposes and as a source of green energy
stands in the center of environmental and economical viewpoints.
Sugarcane Bagasse (SCB) is considered as one of the abundant types of agricultural
wastes. SCB is a recalcitrant material, composed of cellulose, hemicellulose and
lignin. It is organized in a complex network as recalcitrant lignocellulosic material,
which could be successfully degraded using appropriate pretreatment technique into
fermentable sugars, and eventually ethanol, i.e., green energy.
The two-stages pretreatment process using freezing and alkaline agents efficiently
separated the three main components of SCB. Freezing treatment played a
preliminary role in breaking the linkages between components using acetate buffer
solution (pH 4.6) for 2 h at -20°C and solid: liquid ratio of 1:25 (w/w) % . However,
freezing pretreatment resulted in relatively low glucose yield and scarification ratio
of 307.52 mg/g native SCB and 48.5%, respectively, where no total reducing sugars
(TRS) was obtained. Therefore, alkaline pretreatment of the frozen-pretreated SCB
was required.
Further alkaline hydrogen peroxide (AHP) pretreatment was performed for the
frozen-fractionated SCB at -20 °C and 2 h with assistance of Box–Behnken Design
response surface methodology. The investigated key parameters were hydrogen
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peroxide concentration H2O2 (3, 5.5 and 8 % v/v), temperature (25, 42.5 and 60 °C)
and pretreatment duration (1, 3 and 5 h). The results revealed that the statistical
modelling was able to predict the response of glucose yield and TRS production with
R2 = 0.8221 and 0.8814, respectively. After the optimization of (RSM), a model
predicted the optimum values of glucose yield and TRS production of (886.507 mg/g
native SCB and 1.44 mg/mL), respectively; confirmed by the experimental analysis
(888.5 mg/g native SCB and 1.32 mg/mL), respectively. The coincided saccharification
ratio was 97.5%. These results were obtained at H2O2 of 3 % (v/v), 56.93 °C and 1 h
which were 2.88 and 2.01 times higher than that obtained from the freezing
pretreatment for glucose yield and saccharification ratio respectively