Life cycle assessment (LCA) of the energetic use of bagasse in Iranian sugar industry

Abstract Sugar production from sugar cane in Iran has been increased steadily in recent years. The same is true for bagasse remaining after sugar extraction from the sugar cane stalks as one of the main co-products. Nowadays, the residue is mostly disposed and thereby causes environmental concerns. But bagasse can be used for the provision of heat and/or electricity within the sugar refineries. The present study examines and compares the cradle-to-gate life cycle impacts of the energy generation from bagasse along with cane trash based on combustion, gasification or anaerobic digestion (AD) exemplarily in Iran. The paper shows that the three conversion options for bagasse are characterized by quite different environmental key figures. In tendency the combustion option shows the most promising figures compared to gasification and AD especially when considering the potential of exporting the surplus electricity to the grid and also savings of greenhouse gas emissions. However, gasification and biogas production can be potentially characterized by a much better environmental performance in some impact categories. Additionally, the market maturity of the combustion option is much better than the other two options along with also its data availability and reliability.