Assessing the Feasibility of Biofuel Production from Lignocellulosic Banana Waste in Rural Agricultural Communities in Peru and Colombia

Banana cultivation is widespread in tropical and subtropical regions where many rural agricultural communities exist. The banana plant bears fruit once in its life cycle, leaving behind a significant amount of usable agricultural residue. Current practice leaves this residue to decompose in the field spreading diseases and polluting water supplies. We evaluated the technological feasibility of converting lignocellulosic banana residue to ethanol as a localized biofuel production strategy to improve the livelihoods of rural agricultural communities in Peru and Colombia. Liquid hot water (LHW) and steam explosion pretreatment followed by saccharification and fermentation using commercial cellulolytic enzymes and yeast strain were evaluated for three different lignocellulosic residues independently (pseudostems, leaves, and rachis). Stems and rachis, with higher glucan conversion, appeared more promising for biofuel production than leaves (up to 93 and 77 % glucose yields for rachis and pseudostems, respectively). Steam explosion pretreatment allowed higher glucan conversion for stems and leaves, while LHW was better suited for rachis. Pseudostem is the most abundant residue generated with 306,000 tons/year in Uraba Province (Colombia) and 15,000 tons/year in the Chira Valley (Peru) on a dry weight basis. Potential ethanol production in the Chira Valley was estimated in 4.8 and 76.8 ML year^-1 in Colombia, processing stems and rachis combined. This study indicated that there is potential for biofuel production using the lignocellulosic banana residue, which could be expanded to other banana growing communities around the world. Process improvements such as increasing solids loading, water recycling, and optimizing fermentation are still required.