Otimização da extração de pectina do maracujá (Passiflora edulis flavicarpa) usando o método de superfície de resposta / Optimization of pectin extraction from passion fruit (Passiflora edulis flavicarpa) using the response surface method

In the context of aviation decarbonization goals, this study investigated the conversion of wastewater-grown microalgae into sustainable aviation fuel (SAF) precursor via one-step hydrothermal liquefaction (HTL) and upgrading. The highest bio-oil yield achieved was 23.07% (dry basis), at 320 °C for 30 min with 10% NiMo/Al₂O₃ catalyst. The highest heating value, 41.77 MJ kg^–1, was obtained under the same temperature and catalyst concentration, but with a longer reaction time (120 min). Bio-oil yield was significantly influenced by temperature, while the catalyst played a key role in sulfur reduction. The response surface analysis identified an intersection region, around 324 °C with 15% NiMo/Al₂O₃ catalyst, that offers a favorable balance between high yield and low sulfur content. Since reaction time had no significant impact on the results, a 30 min process is recommended to improve energy efficiency. Bio-oil presented a predominance of aromatic hydrocarbons, with smaller fractions of alkanes and cycloalkanes, compounds that are desirable for SAF. These results highlight HTL as a promising pathway for wastewater-grown microalgae valorization. However, further refining and comprehensive technical, economic, and environmental assessments are needed to advance the use of this bio-oil as SAF precursor.

Social Life Cycle Assessment (S-LCA) is a key tool for evaluating social impacts across product life cycles. In agriculture, particularly for fertilizers and biofertilizers, S-LCA offers insights into labor conditions, community well-being, and equity along the value chain. This review highlights methodological approaches, integrated frameworks, and challenges such as limited sector-specific data, methodological inconsistencies, and low reproducibility. The UNEP/SETAC guidelines are emphasized for their stakeholder-based approach aligned with Environmental Life Cycle Assessment (E-LCA). The integration of environmental, economic, and social aspects through Life Cycle Sustainability Assessment (LCSA) is also discussed. Barriers include public resistance to waste-based products, regulatory gaps, and technological limits. However, participatory methods, improved data granularity, and alignment with other sustainability tools have advanced S-LCA's relevance. Tailoring S-LCA to agricultural systems and aligning it with E-LCA, Life Cycle Costing (LCC), and ESG frameworks is crucial to strengthen sustainability assessments and support inclusive, resilient, and innovation-driven agriculture.