Feasibility study of an integrated plant anaerobic digester-fuel cell

Hydrogen can be easily converted to electricity by Fuel Cells (FCs) with high conversion efficiency and without greenhouse gas emission. At present, about 95% of H2 is produced from fossil fuels, causing the emission of not renewable CO2. The remaining 4% is from electrolysis and about 1% is produced from biomass. In alternative to fossil hydrogen can be produced from renewable sources, such as biomass by biological techniques. Biohydrogen can be produced by anaerobic digestion. The fermentation without light, or Dark Fermentation (DF), offers several potentialities since it is not subject to the limitations associated to the photosynthesis. The optimization of digestion process and the characterization of biogas produced are rigorously required in view of development of integrated systems digester-FCs for power production. This work is a feasibility study of a power system that integrate the FCs technology with the biohydrogen production by DF from several kinds of biomass: Arundo donax (not treated and treated by steam explosion), a giant reed and a Syntethic Medium were used in mesophilic conditions (38 °C). High rich hydrogen biogas were obtained with all substrates. Not treated Arundo donax gave the best results with H2 concentrations up to 75% by volume.