Estimating the potential and planning of bioethanol production from agro-residues based on a model-predicted NPP under climate change in Ecuador

抄録

　It is known that bioethanol is an alternative for fossil fuels for reducing GHG emissions, and agro-residues offer potentially significant advantages over other feedstock because of reduced conflict with food production. In this study, which aims to assess biomass energy potential and GHG reduction effects in Ecuador in the present and under climate change, NPP predicted by an ecosystem process model was utilized with a life-cycle GHG assessment and optimization of a biomass energy system. First, the NPP of rice, banana, sugarcane, and corn in the present and under climate change was predicted by Biome-BGC. Next, productivity of each of the four crops was formulated by NPP using government crop statistics and the model-predicted NPP, where the difference in technological and management standards among provinces was considered. Then, based on estimated crop production and geographical distribution of croplands and consumption, a nation-wide bioethanol production plan was proposed. Applying a life-cycle assessment to account for GHGs, crop selection for feedstock and product-delivery allocation, were optimized to maximize GHG reduction. Under the most-severe climate change case, total GHG emission reduction was decreased by 7% of the present condition, caused by decreased crop productivity, longer feedstock transportation, and the use of less-efficient crops.