Biogas production from banana (Musa paradisiaca) waste: Fraction and concentration effect

Banana (Musa p.) waste is one of the potential raw materials for biogas production to supply energy needs in a rural area since its huge quantity of waste in Indonesia. The annual production of banana fruit is more than 7 million tons of which about 10% is wasted due to lack of quality, deterioration, and consumption pattern. Besides it may cause environmental problems, the waste is suitable for biogas production. This research was aimed to investigate its potential use to produce biogas for the rural areas throughout the country. Fraction of the fruit i.e. flesh and peels was subjected to mesophilic (30°C, 1 atm) anaerobic digestion at concentrations of 0.2%VS; 0.4; 0.6; and 0.2; 0.7; 1.2, respectively. Both fractions delivered effective biogas yield at lower concentration 0.2%VS at the highest value of 416 ml STP/g VS (48% degradability) and of 328 ml STP/g VS (36%), respectively. Evaluation of the biogas production based on Modified Gompertz Model resulted in P_o(ml), µ_m(d⁻¹), and λ_p(d) at a value of 5.49, 9,23, and 1.3, respectively. Based on the experimental result, a simple BIOGASCALC_UII program was developed to simulate the size of digester for processing a local source of banana waste. A flat-bottom and conical roof cylindrical digester at a diameter (m) and height (m) of 4.4, and 9.22, respectively can digest 1,000 tons of banana waste per day delivering a daily biogas production up to 69 m³ STP/day (61%CH₄). It is concluded that valorization of the waste into biogas is the best choice to better the environment.