Bioethanol Production from Cassava Mill Effluents Supplemented with Solid Agricultural Residues Using Bakers’ Yeast (Saccharomyces cerevisiae)

Nigeria is the leading cassava and fifth largest oil palm producer, accounting for 54 and 0.93 million metric tonnes respectively. As such during processing large wastes are generated including chaff, palm press fiber, palm kernel shell, empty fruit bunch (EFB) and palm oil mill effluents from oil palm and cassava peels and cassava mill effluents (CME). These wastes are discharged into the ecosystem without treatment where they cause attendant environmental impacts. This study evaluated bioethanol production from CME supplemented with chaff, EFB and cassava peels through separate hydrolysis and fermentation (SHF) techniques. CME with initial pH of 3.6 were used for hydrolysis and results showed a total reducing sugar of 0.31±0.006 mg/ml (CME + EFB -Treatment A), 0.25±0.002 mg/ml (CME +Chaff - Treatment B), 0.43±0.007 mg/ml CME + Cassava peels - Treatment C) and 0.20±0.002mg/ml (CME i.e not hydrolyzed – Treatment D). Fermentation was carried out with Bakers’ yeast (Saccharomyces cerevisiae) under candle jar and highest ethanol volume, weight, concentration, yield and fermentation efficiency was respectively observed as 54.00±0.289ml, 49.56±0.058g, 1.25±0.001%, 0.16 Yp/s and 31.34% at fermentation period of 120 hours (Treatment A), 92.00±0.2889ml, 87.42±0.557g, 0.94±0.010%, 0.35 Yp/s and 68.56% at incubation period of 72 hours (Treatment B), 66.00±0.404ml, 62.84±0.557g, 1.25±0.012%, 0.15 Yp/s and 28.65% at fermentation time of 120 hours (Treatment C), 54.00±0.153ml, 49.47±0.199g, 0.60±0.006%, 0.25 Yp/s and 48.55% at fermentation duration of 144 hours (Treatment D) was observed. The specific gravity of the ethanol produced from the various Treatment ranged from 0.8875 – 0.9673. The study concluded that CME supplemented with EFB, chaff and cassava peels could generate ethanol and thus can be used as a lignocellulosic ethanol feedstock