This work addresses the technical–economic–environmental analysis of a 1G2G ethanol integrated process using immobilized recombinant Saccharomyces cerevisiae and crude sugarcane bagasse acid hydrolysate mixed with molasses. Three case studies were evaluated and compared with the traditional 1G plants. The minimal ethanol-selling price and the life cycle assessment using CML-IA midpoint indicators were chosen as the economic and environmental metrics, respectively. The values found for the ethanol-selling price ranged from 472.92 USD/m³ to 966.53 USD/m³ for the integrated case studies. Compared to the average sales value of 1G ethanol (673.48 USD/m³), the first and second case studies were interesting for their economic viability, while the third case study would require a 43.5% increase in the price of ethanol to achieve production profitability. In the environmental assessment, the integrated 2G ethanol processes of the first and third case studies allowed for the increase in ethanol production per ton of sugarcane processed without decreasing the environmental performance of the process. The third case study presented the lowest environmental impact indicators, except for global warming potential and photochemical oxidation categories, highlighting the importance of the development of biomass pretreatment strategies with lower carbon footprint. The strategy of integrating the 2G process into a 1G ethanol biorefinery offers interesting economic and environmental values, allows the use of hemicellulose, and contributes to the development of 2G processes in sugarcane biorefineries and to the sustainability of the processes.