Biodiesel production by transesterification reaction of sunflower vegetable oil over KOH/Clinker catalysts

Abstract

Biodiesel, a renewable source of energy, was produced through the transesterification of sunflower oil (Plein Soleil) using Clinker supported potassium hydroxide (KOH) catalysts. To assess whether the KOH/Clinker catalysts perform well in the transesterification of sunflower oil with methanol, we tested a series of KOH/Clinker catalysts in the reaction and we evaluated the effect of the amount of active phase on the biodiesel production yield. Different KOH loadings were impregnated on Clinker (15, 25, 35 and 50 wt. %). The prepared catalysts were calcined at 500°C for 3 hours and then characterized by N2 adsorption-desorption and X-ray diffraction (XRD) techniques. The catalytic reactions were performed in a round bottom flask at 60 0C and atmospheric pressure. KOH/Clinker with 35 wt. % loading showed the best catalytic performance. The best reaction conditions in the presence of KOH/clinker (35 wt. %) were determined while modifying the catalyst to oil ratio and the reaction time. After 24 hours of reaction time, the highest fatty acid methyl ester yield (95.2%) was obtained with a catalyst to oil ratio of 10 wt. % and a methanol to oil molar ratio of 15:1. The catalyst reusability was also investigated for several consecutive runs. A deactivation of the 35KOH/Clinker was observed and attributed to the leaching of the K2O active sites, and to the adsorption of glycerol and biodiesel on the surface of the catalyst. The flash point, density and kinematic viscosity of the produced biodiesel were tested and found to be in accordance with ASTM requirements.