Optimization of biodiesel production from sunflower oil transesterification using Ca-K/Al۲O۳ nanocatalysts

In this study, an attempt was made to optimize the conditions for the transesterification of sunflower oil with methanol, catalyzed by Ca-K/Al۲O۳ nanocatalysts, using response surface methodology. The variables that were examined were reaction temperature (۵۵, ۶۵ and ۷۵ °C), reaction time (۱, ۲, ۳, ۴ and ۵ h), catalyst weight base oil (۳, ۶, ۹ and ۱۲ wt%), Ca content (۲۰, ۳۰, ۵۰, ۶۰ and ۸۰ wt%), K content (۵, ۱۰, ۱۵ and ۲۰), methanol:sunflower oil molar ratio (۳:۱, ۶:۱, ۹:۱ and ۱۲:۱), calcination temperature (۶۰۰, ۷۰۰ and ۸۰۰ °C) and calcination time (۱, ۲ , ۳ and ۴ h). Catalyst characterization was done by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR) and temperature programmed desorption (TPD). The maximum fatty acid methyl esters (FAME) conversion efficiency (biodiesel production efficiency) was ۹۸.۳%, at a calcination temperature of ۸۰۰ oC for ۳ h, a methanol-to-oil ratio of ۹:۱, a reaction temperature of ۷۵ °C, a reaction time of ۳ h and a catalyst-to-oil mass ratio of ۹%.

Keywords:

Biodiesel , Transesterification , Ca-K/Al۲O۳ , sunflower oil , Response Surface Methodology