Assessment of Greenhouse Gas Emission Reduction from Biogas Supply Chains in Germany in Context of a Newly Implemented Sustainability Certification

Abstract

Life cycle assessments (LCA) approaches, analysing potential impacts associated with the production and use of biomass for energy and material purposes, have become increasingly important in recent years. An internal project at the Deutsches Biomasseforschungszentrum- DBFZ is investigating, which priority areas have been addressed at the institute with LCA. The preliminary results of the study show mostly practice-linked applications with a focus on the assessment of fuels, their production and technical feasibility. In this publication, we present one of the studies analysed, in which a simplified LCA approach defined in the renewable energy directive (RED II), was applied. Based on primary data from 10 biogas and biomethane supply chains in Germany, the applicability of the RED II greenhouse gas (GHG) emission calculation approach was analysed. Most of the biogas plants assessed were found to be compliant with the required minimum GHG emissions reduction. Storage of digestate, N-fertilization and the use of fossil diesel were identified as the main factors, influencing the GHG intensity of the respective value chains. Additionally, individual calculation requires a high effort for data collection. The availability of tools and default values could therefore support market actors with an efficient implementation of the RED II.