Utilization of banana peel waste for the production of bioethanol and other high-value-added compounds

Abstract

Bananas (Musa sp.) are one of the most produced crops worldwide, surpassing 100 million tons per year, and considering that approximately 30% of their weight consists of peels, the annual generation of these residues is significant. Fruit residues, in general, represent a potential alternative source for obtaining fermentable sugars that can be used in a biorefinery concept and circular economy aiming at waste reuse. In pursuit of bioethanol production within a sustainable production framework, this study optimized pretreatment and enzymatic hydrolysis using a Central Composite Design (CCD 23) with a confidence level of 95% (p < 0.05). The planning variables included sulfuric acid (H2SO4) concentration, banana peel waste mass in the pretreatment stage, and commercial cellulase enzyme (Sigma-Aldrich) concentration in the enzymatic hydrolysis stage. The responses quantified were total reducing sugars. The highest yield of total reducing sugars found after enzymatic hydrolysis was 11.88 g/L, while the ethanol yield was 1.37 g/L. In the recovery of D-Limonene, the obtained value was 0.56 mg/g. Thus, using banana peel waste for D-Limonene recovery in an integrated biorefinery concept contributes to circular economy principles and waste valorization.