Life cycle energy–carbon–water footprints of sugar, ethanol and electricity from sugarcane

Abstract

Sugarcane is an important cash crop used for producing sweeteners and also some bioproducts (alcohol and bioenergy). The current study assesses life cycle energy, carbon and water footprint of sugarcane based sugar, ethanol and electricity in India. A farm to factory gate attributional life cycle assessment (LCA) is conducted to assess the energy and carbon footprints whereas the Food and Agriculture Organization’s (FAO) CropWat model is used to estimate the water footprint (green, blue and grey). For the base case, electricity has the highest energy return on investment (EROI), lowest carbon and water footprints among the bioproducts. The choice of allocation method (economic, mass, and energy) impacts the energy and environmental outcomes of the bioproducts. The comparison among four different sugarcane seasons shows that bioproducts available from Adsali sugarcane have the highest EROI, lowest carbon and water footprints. The findings could lead to improved sustainability of sugarcane bioproducts in India.