Sustainability assessment of large-scale ethanol production from sugarcane

摘要

The present study assesses the sustainability of ethanol produced from sugarcane and examines the environmental feasibility of a large-scale production through the use of: fossil fuel embodied energy and Emergy Assessment including farm and industrial production phases. The study indicates that about 1.82 kg of topsoil eroded, 18.4 1 of water and 1.52 m~2 of land are needed to produce 11 of ethanol from sugarcane. Also, 0.28 kg of CO_2 is released per liter of ethanol produced. The energy content of ethanol is 8.2 times greater than the fossil-based energy required to produce it The transformity of ethanol is about the same as those calculated for fossil fuels. The Renewability of ethanol is 30%, a very low value; other emergy indices indicate important environmental impacts as well as natural resources consumption. The results obtained indicate that sugarcane and ethanol production present low renewability when a large-scale system is adopted.