ABAZIE CHIDIMMA MIRACLE

Given Nigeria's abundant agro-industrial wastes, the study focused on optimizing a ternary blend of cassava peels (CP), coconut husk (CH), and sawdust (SD) to maximize bioethanol yields. Unlike previous studies that examined these feedstocks individually, this work investigated their co-processing potential to overcome disposal challenges and enhance their utilization. The characterization of the feedstocks revealed diverse compositions: CP was rich in hemicellulose, CH presented a balanced composition, and SD was cellulose-rich but highly recalcitrant due to its high lignin content. Utilizing a {3,2} Simplex Lattice Design (SLD) across 15 experimental runs, a Special Quartic model was developed to elucidate the relationship between blend ratios and sugar yield. This model demonstrated high significance (F-value = 88.93, p < 0.0001) and an excellent fit (R² = 0.9916), highlighting substantial synergistic interactions, especially between CP and CH. The optimized blend, consisting of 66.7% CP, 16.7% CH, and 16.7% SD, yielded an impressive experimental sugar yield of 370.31 mg/g, which significantly surpassed the yields from individual feedstocks. Subsequent validation of this optimized blend involved acid pretreatment, enzymatic hydrolysis, and fermentation using Saccharomyces cerevisiae, resulting in an experimental ethanol yield of 0.0644 g ethanol/g biomass. This achievement represents 85.4% of the theoretical yield, confirming a high fermentation efficiency and validating the strategic blending as an effective waste-to-wealth strategy for sustainable bioenergy production