Avaliação do ciclo de vida ambiental da surfactina obtida a partir da bacillus subtilis

Abstract

Surfactants are employed in various sectors, ranging from domestic to industrial appli cations. Their surface tension reduction properties make them widely used in cleans ers, cosmetics, food, agrochemicals, petroleum, and pharmaceuticals. Synthetic sur factants, extensively utilized for their cleaning efficiency and versatility, are predomi nantly derived from petroleum. In contrast, biosurfactants, exemplified by surfactin in this thesis, constitute a variety of surface-active agents obtained from microorganisms, including yeast, bacteria, and fungi, sourced from renewable biomass. This work aims to assess the environmental performance of surfactin, from raw material extraction to the factory gate on an industrial scale, using Life Cycle Assessment (LCA) according to ISO 14040 and 14044 standards. Simulations were conducted with data from differ ent sources and production scales, considering uncertainties due to a lack of primary data on an industrial scale. The production of 1 kg of surfactin was evaluated in seven distinct scenarios, varying fermentative medium and surfactin concentration, consider ing different environmental categories. The results indicate that the impacts of the evaluated scenarios are of the same order of magnitude compared to biosurfactant studies in the literature. Contribution analyses highlighted that utility consumption (electricity, air, and steam), the carbon source used as a substrate, and surfactin productivity ranging from 6-26 % w/w were the most relevant variables for the assessed categories. Alternative scenarios were proposed using residual carbon sources, con verting 16 % w/w of the substrate into surfactin, and changing the electricity matrix supplier. This proposal demonstrated favorable results, reducing global warming by up to 70 % compared to the most favorable scenario among the seven base scenarios. Evaluating Alternative Scenario 5, considering 16 % w/w and utilities from photovoltaic plants with an expanded system boundary that accounts for the impact of waste treat ment compared to LAS, it is possible to highlight that, depending on the waste treat ment adopted, the global warming impact of surfactin may be lower than LAS produc tion. Thus, viable paths for mitigating the environmental impacts of surfactin produc tion's life cycle are evident. Furthermore, technological advancements suggest the possibility of increasing biosurfactant production efficiency, making them more sustain able and commercially competitive compared to fossil-derived surfactants.