Monetization of life-cycle based environmental impacts: a case study on external environmental costs of steel-based wear parts for biogas plants

This study investigates the external environmental costs (EEC) of steel-based wear-parts used in biogas plants by monetizing the life-cycle-based environmental impacts caused throughout the entire life cycle. A simplified cradle-to-grave based environmental life cycle assessment (LCA) was conducted using the commonly applied ReCiPe assessment method. Two monetization approaches were used to comparatively calculate the EEC: recently published TruePrice factors and traditional ReCiPe-based factors. The analysis revealed that EEC account for 8% to 14% of total production costs, indicating significant additional expenses. These costs are primarily driven by the steel used in the components. Sensitivity analysis identified climate change (CC), fossil depletion (FD), and fine particulate matter formation (FPMF) as the most influential impact categories. A 5% increase in the monetization factors resulted in a 1.6% rise in overall EEC. The findings demonstrate that the choice of monetization method significantly influences the estimated EEC. Furthermore, the use of more sustainable steel offers the greatest potential for reducing both environmental and economic impacts associated with steel-based wear parts.