Biogas from anaerobic digestion of biomass (Organic Fraction of Municipal Solid Waste and sewage sludge): trace compounds characterization through an innovative technique (PTR-MS) and detrimental effects on SOFC energy generators, from single cells to short stacks.

The use of biofuels instead of conventional fossil derived fuels is becoming an increasingly crucial topic for future energy systems where environmental issues are also taken into account. Biomass exploitation, including biowaste, appears as a promising means for the energy production and also it contributes to the carbon dioxide emissions reduction. Among the different techniques for biomass exploitation, interesting aspects are covered by the dry anaerobic fermentation of organic waste (OFMSW). In addition also interesting aspects can be achieved by the anaerobic digestion of sewage sludge in waste water treatment plants (WWTPs). Organic waste collection from local municipal areas or from sewage sludge exploitation with subsequent energy valorization through CHP systems allows to reduce the amount of waste disposed into landfills and the pollutant emissions into the atmosphere. Solid Oxide Fuel Cell (SOFC) systems are among the most promising energy generator respect to traditional power generating systems due to their higher electrical conversion values, even at partial loads. This is due to the direct conversion of chemical energy to electrical energy. Hence, fuel cells are very appealing from both energy and environmental point of view. In this work, the main goal was to demonstrate the real feasibility of a SOFC stack system fed by real biogas. This main goal has to be achieved considering three main sub-goals. The first one related to the biogas aspects, mainly on trace compounds investigation followed by the VOCs cleaning for SOFC requirements and then testing the main and the most dangerous VOCs on single cells and on short stacks. These information have been fundamentals for the SOFC generator directly fed by biogas. A 500 We SOFC stack by SOFCpower (Italy) was operated for more than 400 hrs in conjunction with a biogas feeding system.