جستجوی مقالات مرتبط با کلیدواژه « sunflower oil » در نشریات گروه « مواد و متالورژی »

In this study, an attempt was made to optimize the conditions for the transesterification of sunflower oil with methanol, catalyzed by Ca-K/Al2O3 nanocatalysts, using response surface methodology. The variables that were examined were reaction temperature (55, 65 and 75 °C), reaction time (1, 2, 3, 4 and 5 h), catalyst weight base oil (3, 6, 9 and 12 wt%), Ca content (20, 30, 50, 60 and 80 wt%), K content (5, 10, 15 and 20), methanol:sunflower oil molar ratio (3:1, 6:1, 9:1 and 12:1), calcination temperature (600, 700 and 800 °C) and calcination time (1, 2 , 3 and 4 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 98.3%, at a calcination temperature of 800 oC for 3 h, a methanol-to-oil ratio of 9:1, a reaction temperature of 75 °C, a reaction time of 3 h and a catalyst-to-oil mass ratio of 9%.

Conjugated Linoleic Acid (CLA), Glycerol (G) and sunflower oil blends with varying concentration were subjected to enzymatic esterification using a 1, 3- specific immobilized lipase. CLA was used as acyl due to its purported health benefits. The transesterified lipids were evaluated for free fatty acids (FFA) and composition of fatty acids by gas chromatography. Lipozyme Rhizomucor mehei immoblized (RM IM) is preferred for enzymatic esterification because of more CLA incorporation and less free fatty acids at the end of reaction than Lipozyme Thermomyces lanuginosus (TL) IM. Response surface methodology (RSM) was used to determine the effects of three variables Glycerol concentration, reaction temperature, and amount of enzyme on the lipase catalyzed incorporation of CLA into Sunflower oil. The optimum condition for maximum CLA incorporation (96.7% Incorporation Yield), maximum reaction rate (0.0271 M/h) and minimum free fatty acids production (Acid No.2.73) was obtained, at 75 C by using 3 % enzyme and 0.27 M glycerol.