Rotas para produção de combustível de aviação sustentável a partir de algas

Abstract

The increasing emissions of carbon dioxide (CO2) and nitrogen oxides (NOx) have intensified the environmental impacts associated with climate change, highlighting the need to develop more sustainable fuels. This study aims to conduct a literature review on the different production pathways of Sustainable Aviation Fuel (SAF) derived from microalgae, through the analysis of the main technological conversion routes certified by the American Society for Testing and Materials (ASTM). The adopted methodology is qualitative in nature, based on a bibliographic survey primarily conducted using the CAPES and ScienceDirect databases. Among the analyzed pathways, Hydroprocessed Esters and Fatty Acids (HEFA), using microalgae oil, Alcohol-to-Jet (AtJ), and Fischer-Tropsch Synthesis (FT) were selected, the latter two through microalgae gasification. Microalgae stand out as a third-generation feedstock due to their high growth rate, high lipid content, ability to capture CO₂, and the possibility of cultivation in wastewater without competing with the food supply chain. The HEFA pathway is currently the most mature; however, when using algal biomass, its Technology Readiness Level (TRL) decreases to 6–7, with a laboratory yield ranging from 55% to 76%. The AtJ pathway presents an overall energy efficiency of 40% and a TRL of 6. Meanwhile, the FT pathway has a lower TRL of 4–6 and utilizes the entire biomass. From an environmental perspective, SAF production from microalgae can reduce greenhouse gas emissions by more than 50% compared to conventional jet fuel over the life cycle. On the other hand, from an economic standpoint, production costs are 2 to 5 times higher than conventional aviation kerosene, with the HEFA pathway showing the greatest potential for cost reduction in the medium term. It is concluded that, although these pathways present advantageous prospects, none currently demonstrates economic competitiveness or scalability that surpasses or matches fossil kerosene production. Therefore, technological advancements and favorable regulatory frameworks are required to enable the commercial viability of SAF derived from microalgae