Abstract
This project investigated the set-up, optimization of conditions and application of the technique of magnetic-impulse high-frequency cavitation as a single one-step conversion reaction to produce high quality and high yield biodiesel (fatty acid methyl esters) using feedstock from variable sources viz., crude palm oil, and a pure vegetable (sunflower) oil. These conversions were then paralleled to the conversion of used vegetable oils to a useful high quality biofuel applying the same technique. The advantages of magnetic-impulse high-frequency cavitation as a trans-esterification process include: a implementation of a low-temperature process and a cavitation process of reactants within; oils obtained from different sources and varying quality can be used; low energy requirement; “one pass” reaction process; no need for further purification and washing steps are deemed necessary; low alcohol and catalyst usage and no need for alcohol recovery; and a low glycerol content. The optimized conditions were evaluated in terms of oil to alcohol molar ratio, efficiency of the trans-esterification process, amount of catalyst, reaction temperature and reaction duration. The success in producing high quality biodiesel by the technique of magnetic-impulse high-frequency (MI-HF) cavitation was confirmed by efficient, economic and complete formation of fatty acid monoesters using gas chromatography – mass spectrometry (GC-MS), proton (1H-NMR) and carbon-13 nuclear magnetic resonance spectrometry (13C-NMR), attenuated total reflectance fourier-transform infra-red spectroscopy (ATR-FTIR), free fatty acid content and inorganic analysis by inductively coupled plasma – optical emission spectroscopy (ICP-OES). Viscosity, flash point, and the calorific value were the main physical characteristics of fatty acid methyl esters (biodiesel/biofuel) that were evaluated to determine whether it was of an acceptable quality according to standards prescribed by the American Society for Testing and Materials (ASTM).
Ph.D. (Chemistry)