Sustained energy generation from unusable waste steel through microbial assisted fuel cell systems

In the present study, a novel green energy generation process assisted with Microbial Fuel Cell (MFC) principle for generation of electricity from used or wasted steel is explored. Through a unique approach, unused and other steel waste are recast by simple re-melting with a flexible wide composition for generation of green energy. A microbial-assisted electron transfer derived from the degradation of the steel material is utilized for production of green energy in a microbial galvanic reactor system. A. ferrooxidans acts as biocatalysts, facilitating the oxidization of ferrous ion (Fe²⁺) to ferric ion (Fe³⁺). The reaction takes place on the biofilm matrix which results in oxidised reactive zones that endorses further degradation or dissolution of Fe anode. This consequently results in achieving the highest power density as high as 4.92 ± 0.03 mW/cm² at a current density of 0.01 ± 9 mA/cm². The total cost of the unusable steel anode and other accessories are roughly estimated to be 7.94 $/m² and 178.54 $/m² and the gain from unit power generation is estimated to be 3.79 $/W, assuming continuous operation of 4.92 ± 0.03 mW/cm². The present study presents a potent methodology/strategy for the generation of sustainable bioenergy from low-cost, unusable steel materials, which cannot be anyway used as such in other battery systems, say iron air cells/batteries.