Life Cycle Analysis in Sugarcane Bioethanol Production: Energy Efficiency and Environmental Impact in a Sustainability Framework

Abstract

Introduction: The energy transition towards renewable sources is a global priority to mitigate climate change and reduce dependence on fossil fuels. In this context, sugarcane bioethanol has established itself as a sustainable alternative due to its ability to reduce greenhouse gas (GHG) emissions and its economic viability in international markets. However, its production must be evaluated under sustainability criteria, considering environmental impacts, energy efficiency and competitiveness. This study applies a Life Cycle Analysis (LCA) to evaluate the sustainability of bioethanol in Colombia, identifying its main impacts and proposing optimization strategies based on circular economy and efficiency in the use of resources.
Objectives: The objective of this study is to evaluate the environmental sustainability and energy efficiency of sugarcane bioethanol production in Colombia through a Life Cycle Analysis (LCA). The aim is to quantify GHG emissions, determine the impact of the use of natural resources (water and soil), and analyze strategies for waste valorization and optimization of the production process to improve its international competitiveness.
Methods: Life Cycle Analysis (LCA) methodology was applied according ISO 14040, modeling the system using SimaPro software. The functional unit selected was 1 MJ of energy in the form of bioethanol. Primary and secondary data on inputs, production processes and emissions were collected. The study considered environmental impact categories such as climate change, water footprint, energy efficiency and land use, comparing the results with references for fossil fuels and biofuels in other countries.
Results: The results showed that the agricultural phase is the main contributor to GHG emissions, due to the use of nitrogen fertilizers and the mechanization of the crop. However, precision fertilization strategies and logistics optimization allowed a 40% reduction in the total environmental load. In industrial processing, cogeneration with sugarcane bagasse managed, reduce the demand for external energy by 35%. In terms of energy efficiency, Colombian bioethanol presented an energy obtained/energy invested (EROI) ratio of 3.8, higher than the values reported for corn biofuels in North America (EROI of 1.6). Additionally, water consumption for the production of 1 liter of bioethanol was 1.3 m³, significantly lower than the average of 2.5 m³ in other regions of Latin America. Compared to conventional gasoline, Colombian bioethanol reduced CO₂ equivalent emissions by 55%, complying with the environmental standards of the EU Renewable Energy Directive (RED II) and the US Renewable Fuel Standards (RFS). Finally, the valorization of agro-industrial waste allowed the integration of circular economy practices, reducing the environmental impact and improving the competitiveness of bioethanol in international markets.
Conclusions: Sugarcane bioethanol production in Colombia demonstrates favorable environmental performance, highlighted by the reduction of GHG, optimization of water use, and the incorporation of circular economy strategies. However, areas for improvement were identified, such as efficiency in the use of fertilizers and optimization of the distillation process, to minimize additional impacts. This study provides key scientific evidence for the development of public policies and sustainability strategies in the bioenergy sector, consolidating Colombia as a relevant player in the transition to a low-carbon economy.