Avaliação técnico-econômica e ambiental da produção integrada de bioetanol 1G e 2G em biorrefinaria de cana utilizando levedura recombinante

Abstract

With the global increase in energy demand and global concern with climate change on the planet, incentives for research and development of biofuel production processes, such as ethanol, have grown in recent decades, aiming at the full use of biomass and the minimum generation of waste. In order to make possible the implementation of 2G technology in Brazilian 1G biorefineries, studies with economic and environmental assessments are essential to identify possible procedural bottlenecks and help in decision-making. Thus, the main objective of this work was to carry out a technical-economic analysis (TEA) and life cycle assessment (LCA) of ethanol production in a biorefinery that integrates 1G and 2G technology from sugarcane and its waste. For this, three scenarios were evaluated: Scenario I which represents an autonomous Brazilian distillery, while Scenarios II and III present an integrated 1G2G technology addressing different types of pre-treatment (acid and hydrothermal) and using recombinant yeast in the fermentation step. Scenario simulations were performed using the EMSO software, while the LCA was performed using the SimaPro® software. The integrated process increased ethanol production by 14% in Scenario II and 16% in Scenario III compared to Scenario I. The integrated processes (Scenarios II and III) had high production costs, resulting in a minimum selling price of ethanol greater than the marketed value of ethanol around 31% for Scenario II (693.59 US$/m³) and 48% for Scenario III (785.47 US$/m³), which made the processes unfeasible from the point of view economic. In the environmental analysis, both Scenarios did not have the necessary potential to mitigate the environmental impacts of the 1G2G ethanol production process in relation to Scenario I, in order to obtain all categories of environmental impact lower or close to Scenario I. The obtained results indicated the need to select other ethanol production processes as a way to improve the integration of processes in sugarcane-based biorefineries.