Bioenergy recovery from jackfruit waste via biohydrogen production through dark fermentation and power generation through stacked microbial fuel cells

The production of biohydrogen from agricultural waste has the dual advantages of lowering waste and generating clean energy. Dark Fermentation can be utilized for the production of biohydrogen but low substrate conversion efficiency is a major drawback. Combining the process with a microbial fuel cell (MFC), which produces electricity from the substrate's residual energy, may solve this restriction problem. Biohydrogen was produced in our study with the use of Enterobacter aerogenes (MTCC 2822) in batch fermentation using carbohydrate-rich jackfruit peel waste. After batch fermentation, Taguchi Design and Response Surface Methodology (RSM) were used to do single-parameter and multiparameter optimization. After multiparameter optimization, the highest amount of biohydrogen increased by 6%. 5.02 mol H₂/kg COD_reduced was the biohydrogen yield, Additionally, Pseudomonas aeruginosa PA1_NCHU was employed as the inoculum in a Microbial Fuel Cell (MFC) to generate power utilizing the waste fermentation medium. Different carbonate buffer concentrations in the anolyte were used to operate MFCs. A maximum power density of 13.69 W/m³ was obtained in the MFC study. Due to the restricted output of a single MFC, power output was increased by operating MFCs in parallel stacks. In stacked MFCs, an increase in power density of up to 27.90 % was noted. The energy recovery from the dark fermentation and MFC was around 47%. Thus, this paper discusses the integration of dark fermentation with MFC to maximize bioenergy production. Further, the MFCs are stacked to increase the output.