Sinaga, B.A. et al. 2025. The Duration of Sodium Methoxide Catalyst Impregnation in Methanol and Its Impact on the Reduction Monoglyceride Content in Biodiesel Production . Journal of Engineering and Science Application. 2, 1 (Apr. 2025), 17–27. DOI:https://doi.org/10.69693/jesa.v2i1.17.