LCA FOR AGRICULTURE PRACTICES AND BIOBASED INDUSTRIAL PRODUCTS LCA of a biorefinery concept producing bioethanol, bioenergy, and chemicals from switchgrass Francesco Cherubini & Gerfried Jungmeier Received: 18 June 2009 / Accepted: 17 August 2009 / Published online: 20 October 2009 # Springer-Verlag 2009 Abstract Background, aim, and scope The availability of fossil resources is predicted to decrease in the near future: they are a non-renewable source, they cause environmental concerns, and they are subjected to price instability. Utilization of biomass as raw material in a biorefinery is a promising alternative to fossil resources for production of energy carriers and chemicals, as well as for mitigating climate change and enhancing energy security. This paper focuses on a biorefinery concept which produces bioethanol, bioenergy, and biochem- icals from switchgrass, a lignocellulosic crop. Results are compared with a fossil reference system producing the same products/services from fossil sources. Materials and methods The biorefinery system is investigat- ed using a Life Cycle Assessment approach, which takes into account all the input and output flows occurring along the production chain. This paper elaborates on methodological key issues like land use change effects and soil N 2 O emissions, whose influence on final outcomes is weighted in a sensitivity analysis. Since climate change mitigation and energy security are the two most important driving forces for biorefinery development, the assessment has a focus on greenhouse gas (GHG) emissions and cumulative primary energy demand (distinguished into fossil and renewable), but other environmental impact categories (e.g., abiotic deple- tion, eutrophication, etc.) are assessed as well. Results The use of switchgrass in a biorefinery offsets GHG emissions and reduces fossil energy demand: GHG emis- sions are decreased by 79% and about 80% of non-renewable energy is saved. Soil C sequestration is responsible for a large GHG benefit (65 kt CO 2 -eq/a, for the first 20 years), while switchgrass production is the most important con- tributor to total GHG emissions of the system. If compared with the fossil reference system, the biorefinery system releases more N 2 O emissions, while both CO 2 and CH 4 emissions are reduced. The investigation of the other impact categories revealed that the biorefinery has higher impacts in two categories: acidification and eutrophication. Discussion Results are mainly affected by raw material (i.e., switchgrass) production and land use change effects. Steps which mainly influence the production of switchgrass are soil N 2 O emissions, manufacture of fertilizers (espe- cially those nitrogen-based), processing (i.e., pelletizing and drying), and transport. Even if the biorefinery chain has higher primary energy demand than the fossil reference system, it is mainly based on renewable energy (i.e., the energy content of the feedstock): the provision of biomass with sustainable practices is then a crucial point to ensure a renewable energy supply to biorefineries. Conclusions This biorefinery system is an effective option for mitigating climate change, reducing dependence on imported fossil fuels, and enhancing cleaner production chains based on local and renewable resources. However, this assessment evidences that determination of the real GHG and energy balance (and all other environmental impacts in general) is complex, and a certain degree of uncertainty is always present in final results. Ranges in final results can be even more widened by applying different combinations of Responsible editor: Seungdo Kim F. Cherubini (*) Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), Høgskoleringen 5 -E1, NO-7491 Trondheim, Norway e-mail: francesco.cherubini@ntnu.no G. Jungmeier Joanneum Research, Institute of Energy Research, Elisabethstr. 5, 8010 Graz, Austria Int J Life Cycle Assess (2010) 15:53–66 DOI 10.1007/s11367-009-0124-2