Synthesis of KOH@CaO Catalyst by Sol-gel Method for Highly Efficient Biodiesel Production from Olive Oil

Document Type : Regular Article


1 Department of Chemical Engineering, Bushehr Branch, Islamic Azad University, Bushehr, Iran

2 Department of Chemical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran

3 Chemical Engineering-Biotechnology Department, Bushehr Branch, Islamic Azad University, Bushehr, Iran


In this research, biodiesel was produced from olive oil in the presence of KOH-impregnated CaO catalyst (CaO@KOH). To this end, CaO catalyst was produced using the sol-gel method. The percent composition of fatty acids (FAs) in olive oil was measured using gas chromatography (GC) analysis. Also, SEM and BET analyses were performed to evaluate the surface properties of the catalyst. The results indicated that the biodiesel conversion yield of 99±0.2% was obtained under the optimal conditions, i.e. an oil/methanol ratio of 1:15, a catalyst dosage of 1.5 wt.%, a reaction temperature of 65℃, and a reaction time of 4 h, which was the highest biodiesel yield ever achieved from olive oil. The reusability of the catalyst was further investigated through 8 successive cycles of biodiesel generation, and the results indicated that the reduction of biodiesel conversion yield was less than 2% after 4 cycles of reusing the catalyst, confirming the high potential of the aforementioned catalyst. Also, the production cost of the KOH/CaO catalyst was calculated to be 108.45 USD/Kg, which had a reasonable cost. Moreover, the physical properties of the produced biodiesel were within the standard range.