The growth in the number of vehicles circulating has led to a proportional increase in polluting gas emissions. Bioenergy can be used to help meet these increasing energy demands and mitigate environmental impacts. This work verified the effect of the content of ethanol on the exergy and exergoenvironmental analyses of a spark-ignition engine. Different gasoline–ethanol mixtures were tested along with hydrous ethanol (4.6% water by volume). The thermodynamic data refer to wide-open throttle conditions and variable engine speeds. The life cycle assessment methodology quantified the environmental impacts associated with equipment and fuel using the Eco-indicator 99 method. Pollutants emitted during combustion were measured and included in the environmental assessment (nitrogen oxides, carbon monoxide, and dioxide). Hydrous ethanol at 1500 rpm presented the highest energy efficiency. The effects of the environmental impact rate of pollutant formation and exergy efficiency were significantly higher than the environmental impact rate of fuel. The lowest specific environmental impact of the product (brake power) was 24.39 mPt/MJ, obtained with the fuel blend with 50% ethanol at 2500 rpm. The combined evaluation of the exergoenvironmental factor and the relative difference in environmental impact indicated the optimization priorities and where improvements should be directed.

Sugarcane‐derived ethanol is a key renewable fuel, contributing to energy security and climate change mitigation by replacing fossil‐based fuels in tropical regions. This article introduces an integrated exergy–economic–environmental–life cycle assessment (LCA) framework for a sugarcane cogeneration system, providing novel benchmarks and optimization insights for sustainable ethanol and bioelectricity production in Northeast Brazil. An LCA was developed to provide environmental data for the exergoenvironmental analysis. The system has a processing capacity of 200 t/h of sugarcane and produces 33 MW of electricity using two steam turbines, with 22 MW of electricity being exported and 480 m ³ of hydrated ethanol produced daily. The furnace presents the highest exergy destruction rate (32.53%). The global exergy efficiency is 29.95%. The specific costs of ethanol and electricity are 0.3882 US$/L and 0.05929 US$/kWh (59.29 US$/MWh). The cost of sugarcane is primarily due to diesel consumption in the agricultural stage and transportation to the site. The specific environmental impacts of ethanol and electricity are 829 mPt/L and 112.1 mPt/kWh. The combustion and bioelectricity phase, as well as the juice concentration phase, should have their efficiencies improved, with financial investments to reduce the cost rate of exergy destruction and increase exergoeconomic performance. The combustion and bioelectricity phase presents the highest environmental impact due to furnace emissions, while efficiency improvements in juice concentration and distillation can reduce exergy destruction and related environmental impacts.