The increasing demand for sustainable energy sources has driven interest in biodiesel production, a renewable alternative to fossil fuels. This paper investigates the production of biodiesel using eggshells as a catalyst in the transesterification of waste cooking oil. Because of their abundance, affordability, and capacity to transform into calcium oxide (CaO), a premium base catalyst, eggshells—which are abundant in calcium carbonate—are an important catalyst. They are therefore a more environmentally responsible and sustainable substitute for conventional catalysts made from non-renewable materials. The catalyst was prepared by three methods: dried at 105°C, calcinated at 900°C, and refluxed at 600°C. The results revealed that the highest yield of produced biodiesel from waste cooking oil was 81.42% when refluxed eggshell was used. The first case of optimization was done on dried eggshell at 105°C; the obtained yield was 76.92% and 80.55% for reaction times of 1 hr and 2 hr, respectively. While the second case was done on dried eggshell at 105°C and calcined at 900°C, the obtained yield was 84.16% for the lowest catalyst (calcined at 900°C) ratio. The final case was recycled calcined eggshell, which gives a good yield. The costs of producing one ton of biodiesel from eggshell and sodium hydroxide (NaOH) catalysts are $1,560 and $1,566, respectively. The used oil, eggshell catalyst, and produced biodiesel were characterized.

Keywords: biodiesel, eggshell catalyst, waste cooking oil, calcium oxide, transesterification

Conference Title

Engineering for Palestine Conference held at Palestine Polytechnic University, Hebron, Palestine

Conference Country

Palestine

Conference Date

Sept. 29, 2025 - Sept. 30, 2025

Conference Sponsor

Palestine Polytechnic University, Hebron, Palestine