Hydrogen from biogas: A techno-economic comparison with biomethane grid injection and bio-CNG at small scale

This study presents a comprehensive techno-economic assessment of biogas utilization pathways, comparing the production of biomethane, bio-CNG, and hydrogen via biogas steam reforming. The analysis is based on an extensive dataset comprising vendor quotations and literature data. The particular focus of this study lies on raw biogas capacities between 50 Nm 3 /h and 400 Nm 3 /h, a capacity range in which biogas upgrading is generally considered too expensive. The results reveal pronounced economies of scale for all investigated pathways, driven primarily by the degression of investment costs. For a raw biogas flow rate of 400 Nm 3 /h, the levelized cost of biomethane is estimated to 10–12 ct/kWh, while the levelized cost of bio-CNG and hydrogen are roughly 1.3 €/kg and 10.4 €/kg, respectively. These values represent the full pathway costs, including compression and grid injection for biomethane, or compression and filling tube bundles or trailers for bio-CNG and hydrogen. All costs are reported without considering incentives or revenues from quota trading schemes. All biogas utilization pathways exhibit strong sensitivity to the biogas price, which represents the dominant cost component. The profitability of all investigated pathways is strongly influenced by achievable product selling prices, which depend on market structure, regulatory frameworks, quota trading schemes, and end-use applications. The cost correlations and levelized costs derived in this study provide an updated basis for decision-making, particularly in the small-scale biogas sector, where standardized, modular processes are gaining market relevance.