Evaluation of Attalea tessmannii Kernel Oil as a Feedstock for Biodiesel Production by Methanolysis and Ethanolysis

Abstract Biodiesel production has been investigated due to its potential to mitigate pollutant gas emissions through the partial replacement of petroleum diesel. Although the technology is well-established, continued research focuses on the evaluation of alternative feedstocks and production routes that improve performance and economic viability. In this study, oil extracted from the kernels of Attalea tessmannii, a highly saturated oil obtained from an Amazonian fruit, was assessed as a feedstock for biodiesel production via methanolysis and ethanolysis. Crude and neutralized oils were subjected to base-catalyzed transesterification, and the resulting biofuels were characterized in terms of ester content, density, kinematic viscosity, acidity index, thermal behavior, and flash point. Oil refining resulted in an overall yield of 87%, while transesterification achieved ester contents of up to 93% for methanolysis and 97% for ethanolysis. The methanolysis products did not meet the minimum ester-content requirement specified by EN 14214 for FAME and also exhibited kinematic viscosities below the EN 14214 range. In contrast, the product obtained by ethanolysis of neutralized oil showed the most favorable overall fuel-quality profile among the evaluated routes, with density of approximately 863 kg m–3, kinematic viscosity near 3.1 mm2 s–1, acidity index below 0.5 mg KOH g–1, and flash point of 139 °C. A preliminary economic assessment revealed raw-material costs ranging from 0.536 to 0.712 USD kg–1. Although the crude oil–ethanol route presented the lowest production cost and the highest contribution margin per hour, the product obtained from this route exceeded the maximum acid-value limit considered in this study. These findings provide the first experimental evidence that Attalea tessmannii kernel oil is technically compatible with conventional base-catalyzed transesterification, with ethanolysis of neutralized oil offering the most favorable route among those evaluated.