Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Forest Resource Management
Benjamin E Dawson-Andoh
Research into biodiesel as a substitute for petroleum diesel has been ongoing since the energy crisis of the 1970's. The concern for the effect on the use of edible vegetable oils as feedstock has increased. Tall oil fatty acids have been considered as a non-food substitute and various works have been done on it. In this study, sulfuric acid and Amberlyst BD 20 were used as homogeneous and heterogeneous catalysts respectively in the production of biodiesel from Tall oil fatty acids in a batch reactor. The treatment conditions for the homogeneous catalysis varied the factors of fatty acid to methanol molar ratio, the temperature, the catalyst concentration and the time of the reaction. Fourier transform infrared (FTIR) spectroscopy was used to monitor the reaction in real time to show when conversion of reactants to products is complete. Gas chromatography showed the fatty acids present in the oil sample. The major fatty acids present are oleic and linoleic acid. Acid value, the kinematic viscosity, and specific gravity were all determined. The heterogeneous catalysis kept the temperature of the reaction constant within 75--80°C. The molar ratio, catalyst concentration and time of reaction were varied. Results showed that the homogeneous catalysis gave a higher yield that the heterogeneous catalysis. The acid value was for optimum production of the heterogeneous catalysis was lower than the homogeneous catalysis. Also the solid catalyst was recycled 4 times without losing its activity.;The storage of energy is as important as the source of the energy itself. Research into thermal energy storage systems has been ongoing but most of the research has focused on fossil fuel sources as the feedstock. This study therefore evaluated fruit oils and their synthesized products as feedstock for use as phase change materials (PCMs) in latent heat storage in thermal energy storage systems. Seeds of Allanblackia were processed into oil and also oils from shea butter and palm kernel oil were purchased commercially and further processed. Differential scanning calorimetry (DSC) was used to determine the enthalpy values as well as the temperatures at melting and crystallization. Thermo-gravimetric analysis (TGA) was used to determine stability of the samples within the temperature of interest. Fourier transform infrared spectroscopy (FTIR) spectra were taken to determine the chemical stability of the samples. Thermal cycling of the samples for 1000 times was used to evaluate the stability and reliability of the sample after continuous use of the sample over a very long period. Results showed that Allanblackia oil gave a high enthalpy value of 80.53 J/g at a melting point of 34.74°C. Allanblackia oil was chemically stable but showed a slight oxidative instability around 37°C. However, Allanblackia oil did not decompose after 1000 thermal cycles, and can therefore be considered suitable for use as a PCM. The oils from shea butter and palm kernel are all unsuitable for use as PCMs because their enthalpy values are not latent energies. The fatty acids produced from the oils showed that Allanblackia fatty acids gave the highest latent heat values that are thermally stable and reliable within the desired temperature of interest, as well as chemically stable for use as a PCM for thermal energy storage. The fatty acids from shea butter and palm kernel oil did not show latent heat properties and therefore could not be considered as PCMs for thermal energy storage systems. The methyl esters produced from all the oils did not show potential for their use as PCMs for thermal energy storage systems but the Allanblackia butyl ester and shea butter butyl ester are capable of being considered for thermal energy storage systems. They are thermally stable and reliable within the desired temperature of interest, and also chemically stable. The butyl ester of palm kernel is unsuitable for use as a PCM for thermal energy storage system since it is chemically unstable.
Lawer-Yolar, Gideon Sackey, "Biodiesel from Tall Oil Fatty Acids and Physico Thermal Properties of Tropical Tree Fruit Oils as Thermal Energy Storage Systems" (2015). Graduate Theses, Dissertations, and Problem Reports. 6044.