Feasibility Study of Small-Scale Ethanol Production from Sweet Potato Peels in Taraba State

Sweet potato cultivation in Taraba State, North East Nigeria, generates large volumes of peel waste during household and commercial processing that currently has no structured valorisation pathway. This study evaluates the technical feasibility of bioethanol production from sweet potato peels using dilute acid pretreatment followed by enzymatic hydrolysis and yeast fermentation. Peels were collected from food processing units in Jalingo, dried to less than 10% moisture, milled, and subjected to dilute sulphuric acid pretreatment at 1.0% concentration and 120 degrees Celsius. Enzymatic saccharification was conducted using commercially sourced cellulase and amylase enzyme cocktails at 50 degrees Celsius for 48 hours. Fermentation of the hydrolysate was carried out with Saccharomyces cerevisiae at 30 degrees Celsius for 72 hours. Ethanol was recovered by distillation and characterised for purity, density, and calorific value. Reducing sugar concentration after enzymatic hydrolysis averaged 34.2 g/L. Fermentation broth ethanol content reached 4.8% v/v, and distilled ethanol purity was 78.3%, upgradeable to fuel grade through dehydration. Mass balance calculations indicated an estimated bioethanol yield of 142 litres per tonne of dry peel substrate. Economic assessment indicated a payback period of approximately 3.2 years for a 50-litre per day production unit. The study establishes a viable baseline for small-scale biorefinery development using sweet potato peel waste in Taraba State. Keywords: sweet potato peel, bioethanol, enzymatic hydrolysis, fermentation, Taraba State