Pretreatment of banana agricultural waste for bio-ethanol production: Individual and interactive effects of acid and alkali pretreatments with autoclaving, microwave heating and ultrasonication

- Banana plant waste is a potential substrate for biofuel.
- Alkali assisted ultrasonication is the effective pretreatment option.
- Pretreatment conditions were optimized through numerical point prediction tool.
- It was found that crystallinity of raw material affects the yield of reducing sugar.
- The maximum yield of reducing sugar was found in banana leaf (47.33).

Banana agricultural waste is one of the potential lignocellulosic substrates which are mostly un-utilized but sufficiently available in many parts of the world. In the present study, suitability of banana waste for biofuel production with respect to pretreatment and reducing sugar yield was assessed. The effectiveness of both acid and alkali pretreatments along with autoclaving, microwave heating and ultrasonication on different morphological parts of banana (BMPs) was studied. The data were statistically analyzed using ANOVA and numerical point prediction tool of MINITAB RELEASE 14. Accordingly, the optimum cumulative conditions for maximum recovery of reducing sugar through acid pretreatment are: leaf (LF) as the substrate with 25 min of reaction time and 180 °C of reaction temperature using microwave. Whereas, the optimum conditions for alkaline pretreatments are: pith (PH) as the substrate with 51 min of reaction time and 50 °C of reaction temperature using ultrasonication (US).