Microbial fuel cells continuously fuelled by untreated fresh algal biomass

摘要

Microbial fuel cells (MFCs) are energy transducers whereby organic matter is used as the electron donor to electroactive anaerobic microorganismes and the anode as their electron acceptor. An avenue of research in this field is to employ algae as the organic carbon source for the MFCs. However, in all studies demonstrating the feasibility of this principle, the algal biomass have always been pre-treated prior being fuelled to MFCs, e.g. centrifuged, dried and ground into powder, and/or treated by acid-thermal processes. The alternative presented here, is a flow-through system whereby the MFCs were continuously fed by the output of a photo-bioreactor. The system comprised of i) a culture of Synechococcus leopoliensis grown continuously in a photo-chemostat, ii) a pre-digester initiating the digestion of the phototrophs and producing a fuel devoid of oxygen, and iii) a cascade of 9 MFCs fluidicly and electricaly independant. At its best, this inline system produced 42 W of electrical power per cubic metre of fresh culture (6.105 cells mL-1).