Sugarcane contributes to the sustainability of Brazil s energy matrix by providing 1G bioethanol, which helps decarbonize both the transportation and electricity sectors. The industry has also been integrating anaerobic digestion of waste, energy utilization of straw, and the use of bagasse for 2G ethanol production. Conversely, microalgae are an underutilized form of biomass at the industrial level, primarily due to the high energy costs required to concentrate and process them into biofuels. This work simulates the integration of 1G2G ethanol production from sugarcane with biodiesel from microalgae, through biogenic CO₂ from fermentation and exhaust gases from the combustion of bagasse, biogas, and straw. With the objective of performing a 4E evaluation (energy, exergy, economic, and environmental) of three biorefinery configurations, the processes were simulated using Aspen Hysys v8.8 to characterize production scales and determine global performance indicators. The effects and statistical relevance of variables on these responses were evaluated through a design of experiments, enabling the development of models and identification of relevant conditions through surface optimization. Notably, the proposed integration can maintain the sector s energy self-sufficiency, producing products with low carbon intensity (15.75 g CO2eq/MJ). At the bold level, a production scale of 55 L biodiesel/t sugarcane and 60.2 MWh/t sugarcane of electricity surplus was achieved. In a multi-criteria analysis using global desirability, the biorefinery maximizes its performance when 2G ethanol production is disregarded, and the microalgae exhibit a lipid content greater than 30 percent by mass. Finally, the project presents internal rates of return greater than 12 percent, with a probability of success (NPV greater than 0) exceeding 60 percent, according to Monte Carlo simulations. Nonetheless, R(and)D is necessary to overcome technological barriers inherent to cultivating high-oil, high-productivity microalgae so as to further contribute to decarbonizing the transport sector in Brazil.