Techno-economic assessment of biomass-based natural gas substitutes against the background of the EU 2018 renewable energy directive

This paper investigates biomethane and BioSNG production processes against the background of the 2018 renewable fuel directive of the European Union (EU). The investigated biomethane processes use manure, clover grass, and grass silage as feedstock, are based on membrane separation gas upgrading processes, and generate 1.0 and 4.8 MW of biomethane. The investigated BioSNG processes use wood chips as feedstock, are based on the dual fluidized bed steam gasification technology and the VESTA SNG process from Amec Foster Wheeler, and generate 6.1, 12.2, and 49.1 MW BioSNG. The techno-economic assessment shows that the biomethane processes have, in general, a lower break-even price for the generated natural gas substitute. However, their scalability is limited and at larger scale (49.1 MW BioSNG capacity), the BioSNG processes become competitive. The 1.0 MW biomethane and all BioSNG plants meet the 2018 renewable fuel directive of the EU. In contrast, the 4.8 MW biomethane process does not meet the directive as the feedstock, which is mainly based on energy crops, causes significant CH4 and CO2 emissions.