Article in Press
This article is currently in the Just Accepted phase. The final published version may have formatting changes or additional corrections.
Abstract
The increasing global energy demand and the environmental burden of fossil fuels have intensified interest in renewable alternatives such as bioethanol. This study reviews the conversion of agro-industrial residuesspecifically yam peels, cassava peels, and brewer’s spent grain (BSG)into bioethanol, emphasizing yield variations, process optimization, and sustainability implications. Differences in ethanol yields reported across studies are attributed to the diverse proximate and chemical compositions of the feedstocks, as well as to variations in pretreatment and pre-analysis processing. Pretreatment plays a vital role in exposing cellulose and hemicellulose, enabling efficient hydrolysis and fermentation. High ethanol yields are strongly linked to feedstocks with elevated starch content, low protein, and low dry matter. Advances in experimental design and process optimization are critical for improving conversion efficiency, reducing production costs, and enhancing the economic feasibility of commercial-scale applications. Beyond energy generation, valorizing agricultural wastes contributes to circular economy strategies by transforming low-value byproducts into high-value energy resources, while simultaneously addressing waste management, energy security, and climate change mitigation. This review highlights the challenges and opportunities in lignocellulosic biomass valorization, underscoring the need for continued technological innovation to achieve sustainable biofuel production.
