The Comparative Life Cycle Assessment of Fuel Grade Bioethanol Production from Sugarcane, Cassava and Corn in Lampung

Abstract

Bioethanol is a renewable energy source with strategic potential in supporting the transition to a sustainable energy system. The need for low-carbon fuels is driving various countries to utilize biomass as an alternative to fossil fuels, particularly in the transportation sector. Lampung Province has three main commodities that can be processed into bioethanol: sugarcane, cassava, and corn, each with distinct agronomic and technical characteristics. Differences in sucrose and starch content, processing energy requirements, and cultivation input intensity make a comprehensive comparison between these raw materials essential. Using a cradle-to-gate Life Cycle Assessment (LCA) approach, this study evaluates the energy performance, bioethanol productivity per land area, and global warming potential of these three production pathways. The results showed that on the same land area (2 ha), sugarcane produced the highest bioethanol yield, which was approximately 8,425 liters, followed by cassava with ±8,310 liters, and corn with ±3,232 liters. In terms of energy, sugarcane performed best with an EROI of 6.74 due to its high energy output and energy contribution from bagasse, while cassava and corn showed EROI values ​​of 1.63 and 1.24, respectively. However, sugarcane had the largest carbon footprint with total emissions of 17,507.45 kg CO₂-eq, mainly due to the use of nitrogen fertilizers and N₂O emissions from the land. Cassava showed intermediate emissions, while corn had the lowest total emissions (6,577.58 kg CO₂-eq) despite its low bioethanol productivity. These findings confirm the trade-off between energy productivity and environmental impact, and indicate that improving the efficiency of fertilizers, land management, and conversion processes are key aspects in developing a sustainable bioethanol industry in Indonesia.