Multi-indicator assessment of innovative small-scale biomethane technologies in Europe

Innovative small-scale biogas plants, including upgrading solutions to affordable biomethane, are necessary to tap into the spatially distributed potentials of organic waste. This research identified and assessed novel small-scale technologies before market-entry maturity in the key process steps of the biomethane chain. We assessed technical, economic, and ecological indicators, and compared them to larger-scale references. The assessment included 7 pre-treatment, 13 digester, and 11 upgrading systems all at the small scale. We collected recently available data for Europe (2016–2018) for small-scale technologies (<200 m ³ ; raw biogas per hour). In the literature we did not find such a comprehensive assessment of actual European small-scale innovative non-market-ready technologies for the production of biomethane. Several conclusions were drawn for each of the individual process steps in the biomethane chain, e.g., the economic indicator calculated for the upgrading technologies shows that the upgrading costs, for some of them, are already close to the larger-scale reference (about 1.5 €ct/kWh raw biogas). Furthermore, biomethane production is absolutely context-specific, which dramatically limits the traditional way to evaluate technologies. Hence, new ways of integration of the technologies plays a major role on their future R&D.