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.
Biodiesel is a key fuel for a zero-carbon future. Enzymatic synthesis using renewable materials can make it even more environmentally friendly. However, high enzyme costs and limited reuse hinder its economic feasibility. This study assessed the techno-economic and environmental performance of different processes for ethyl ester biodiesel production. The scenarios evaluated include: transesterification of soybean degummed oil using free and immobilized Eversa Transform 2.0, chemical alkaline catalysis of soybean oil, and transesterification of waste oil using ET. The main metrics were net present value and global warming potential. Results showed that the free enzyme outperformed the immobilized enzyme economically. However, chemical catalysis had an NPV nearly double that of the best free enzyme option. Sensitivity analysis revealed that enzyme cost and reuse rate were critical to net present value. Transesterification of waste oil with enzyme reuse had the lowest GWP (4.21 g \mathrm{CO_{2eq}} /MJ), making it the most environmentally favorable scenario. While life cycle assessment indicated lower global warming potential for enzymatic catalysis, further study is needed on emissions from enzymes. Depending on the enzyme and reuse rate, chemical catalysis might result in lower overall emissions. Integration with the biorefinery makes large-scale enzymatic biodiesel production economically viable and with low \mathrm{CO_{2eq}} emissions.