Wastewater treatment and energy generation for dark fermentation bioreactor: preliminary results

Abstract

H2 is known as the main energy vector in the global energy transition. However, the use of fossil fuels for its production remains the most widely used primary source. Among the new alternatives for the organic production of H2, the Dark Fermentation process is an attractive technique since the raw material is residual biomass. H2 is currently used for transport and fertilizer production. Hence, this study aims to evaluate the feasibility of producing electricity from H2 produced in a Dark Fermentation process by treating synthetic wastewater in a packed bed bioreactor coupled with a fuel cell. The results showed that the maximum H2 production rate and H2 yield were 108 mL H2/h.L and 10.57 mol H2/ mol, respectively; the maximal current value was ca. 13.7 mA for an active electrode area of 10 cm2; and the higher tension was 1.3. Moreover, the Fuel Cell generated an average current of 3.12 mA for 55 h with a voltage of 210 mV. It can be concluded that dark fermentation promotes electricity generation. However, it is still necessary to develop storage techniques for H2 to maintain the electricity generated continuously.