Bio-hydrogen from municipal wastes: preliminary results of MODSEN project

Hydrogen production via biological routes, as dark fermentation of organic biomass, is a suitable alternative and renewable energy source especially if waste such as agricultural residues, agroindustrial waste, and organic municipal waste, are used. The aim of the MoDSEn project is the construction of a pilot plant for biohydrogen production from food waste and waste activated sludge, considering the whole process, from waste pre-treatment to hydrogen separation systems and electric energy production. The dark-fermentation semi-continuous process was performed using a waste/sludge ratio of 1:1 in VS and digestate as inoculum. Preliminary results indicate that the optimal organic loading rate is between 10 and 15 kgVSfeed/m3 reactor, with a hydraulic retention time of 3 days and with pH control between 5.2 and 5.5. The specific gas production at steady state condition was 120 NL/kgVS with about 30% of hydrogen content. To take full advantage of the proposed process it is important to have a holistic view of the whole approach, considering also the advantage of bio-based solution such as purple non sulphur bacteria (Rhodopseudomonas palustris) to improve hydrogen yields through the use of rganic acid production in dark fermentation.