Biodiesel production from waste cooking oil using a new heterogeneous catalyst SrO doped CaO nanoparticles
Apisit Prokaewa, Siwaporn Meejoo Smith, Apanee Luengnaruemitchai, Mathi Kandiah, Supakorn Boonyuen
Abstract
Biodiesel production from waste palm cooking oil (WPCO) was studied. Calcium oxide with a strontium ion additive (Sr-CaO) was employed as a catalyst in transesterification reaction of used palm oil with methanol. The Sr-CaO was synthesized by co-precipitation method between SrCl2 and Ca(NO3)2, then calcined at 900°C for 5 h. The catalyst was characterized by using thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), Scanning electron microscope (SEM), and Fourier transform infrared spectrometer (FT-IR). The morphology and elements content of Sr and Ca in the catalyst were confirmed by SEM-EDX. The approximate catalyst diameter is 12.6±5.9 µm. The highest conversion was 99.33% (the reaction time 3 h, 5%w/w catalyst, methanol to oil molar ratio 9:1 and reaction temperature 80°C). The catalyst can be used up to the sixth cycles with a good yield. The synthesized biodiesel meet the requirement of standard biodiesel (EN 14103 and ASTM D445). These findings suggest that calcium oxide with a strontium ion additive (Sr-CaO) is an effective renewable biodiesel catalyst.