Transesterification Kinetics, Thermodynamic Modeling, and Engine Emissions of Methyl Esters from Ricinodendron heudelotii Seed Oil

International Journal of Chemistry | Vol. 15, No. 1, January 2024 | pp. 1–8

DOI: 10.46882/2024/IJC/000183

Article Type: Original Research Paper

Title: Transesterification Kinetics, Thermodynamic Modeling, and Engine Emissions of Methyl Esters from Ricinodendron heudelotii Seed Oil

Names of Authors: M. C. Okonkwo¹, T. H. Nguyen²*

Authors’ Affiliations:
¹Department of Industrial Chemistry, Enugu State University of Science and Technology, Enugu, Nigeria.
²Department of Chemical Engineering, Hanoi University of Science and Technology, Hanoi, Vietnam.

Abstract: Utilizing non-edible agricultural crop lipids as chemical feedstocks for alternative biodiesel synthesis promotes green energy targets without competing with global food security reservoirs. This study investigates the transesterification kinetics and chemical properties of biodiesel synthesized from essessang (Ricinodendron heudelotii) seed oil. Because of an elevated initial free fatty acid content (5.84 mg KOH/g), a two-step acid-base catalyzed transesterification route was deployed. The first step reduced the acid value below 1.0 mg KOH/g using 1.2% v/v sulfuric acid in methanol, followed by standard base-catalyzed transesterification with sodium methoxide. Fatty acid methyl ester (FAME) yield was optimized at 93.8% using a 6:1 methanol-to-oil molar ratio, a catalyst concentration of 1.0 wt% NaOH, and a process temperature of 60°C for 90 minutes. Kinetic analysis confirmed that the transesterification process followed pseudo-first-order reaction mechanics with an activation energy of 41.5 kJ/mol. Fuel properties of the prepared biodiesel, including kinematic viscosity (4.32 mm²/s at 40°C), flash point (164°C), and cetane number (53), matched international ASTM D6751 regulatory specifications. Diesel engine tests using a B20 blend showed a 14.5% reduction in smoke opacity compared to conventional diesel.

Keywords: Ricinodendron heudelotii; Biodiesel; Transesterification; Reaction kinetics; Activation energy; Fuel properties

Manuscript Timeline: Received: July 02, 2022; Revised: August 14, 2022; Accepted: September 10, 2022; Published: January 04, 2024.

Citation: Okonkwo, M. C., & Nguyen, T. H. (2024). Transesterification Kinetics, Thermodynamic Modeling, and Engine Emissions of Methyl Esters from Ricinodendron heudelotii Seed Oil. International Journal of Chemistry, 15(1), 1–8.

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