Banana Waste-to-Energy Valorization by Microbial Fuel Cell Coupled with Anaerobic Digestion

Abstract

Banana is the most cultivated fruit plant in the world. It is produced in Latin America, Asia and Africa. India and China are the world’s largest banana producers, with almost 41% of the world’s production. This fruit reaches a total world production of 158.3 million tons per year. However, during their production cycle, the banana agroindustry produces large volumes of solid waste derived from overripe fruit. It contributes between 8–20 percent of the waste (around 100 kg of banana waste for every ton of banana produced). Therefore, the use of overripe banana waste represents a huge opportunity for bioenergy production. This work demonstrates that banana waste can be further used for power generation using a microbial fuel cell (MFC) coupled with anaerobic digestion (AD). First, the maximum methane production (MMP), methane production rate (MPR) and biochemical methane potential (BMP) were measured using an anaerobic batch bioreactor for 64 days of monitoring. Finally, the digestate generated from AD was used in the MFC to determine the polarization curve, maximum voltage, maximum power density (MPD), resistance and current. As a result, the AD generated an MMP of 320.3 mL, BMP of 373.3 mLCH4/gVS and MPR of 18.6 mLCH4/Lb⋅day. The MFC generated 286 mV (maximum voltage), 41.3 mW/m2 (MPD), 580.99 Ω (resistance) and 0.0002867 A (current). Both processes together produced a total bioenergy of 13.38 kJ/gVS. This coupled system showed a suitable and promising use of banana waste for ecofriendly bioenergy generation. Therefore, this feedstock could be taken advantage of for generating sustainable processes and developing a circular economy in the banana agroindustry.