Abstract—Particle pollution released from diesel engines is
an important environmental concern. A replacement of regular
diesel by fatty acid esters is continuously studied to reduce
pollutants. This paper presents the experimentation of Palm
Ethyl Ester (PEE) and its blends, running on a High-Speed
Direct Injection (HSDI) diesel engine at a constant speed of
3,000 rpm under various electrifications. PEE was
transesterified by palm olein and anhydrous ethanol under the
alcohol/oil molar ratio of 6:1 catalyzed by potassium ethoxide at
1%. The neat and blended PEE in regular diesel indicated the
reduction of exhaust emissions in the HSDI engine. The
unburned hydrocarbons, carbon monoxide, black smoke, and
particulate matter were reduced by 30%, 49%, 36%, and 45%,
respectively. The nitric oxide was elevated by 14%. Additionally,
the brake thermal efficiency decreased, and the brake specific
fuel consumption increased by 9% and 24%, respectively. The
PEE blended with increasing regular diesel led to the
improvement of engine performance and the decrease of nitric
oxide according to regular diesel proportions increased.
Keywords—engine performance, exhaust emissions, HSDI
diesel engine, PEE, regular diesel
Cite: Charoen Chinwanitcharoen, Cherdphong Seedao, Sathaporn Chuepeng, and Ekkachai Sutheerasak, "Emissions from High-Speed Direct Injection Diesel Engines Using Palm Ethyl Ester Fuel Produced with Potassium Ethoxide Catalyst," International Journal of Environmental Science and Development vol. 17, no. 1, pp. 77-85, 2026.
Copyright © 2026 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).