Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 23, 2007) Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 72-80).

Because of the depletion of the world’s petroleum reserves and the increasing environmental concerns, biodiesel, as a low-emission renewable fuel and one of the best substitutes for petro-diesel fuel, has attracted great public interest over the past decades. At present, camelina oil has been considered as a low-cost feedstock for biodiesel production because of its high oil content and environmental benefits. In the present study, the optimization of biodiesel production and purification from camelina oil is studied extensively in order to maximize the biodiesel yield. The orthogonal array design is used to optimize the biodiesel production and four relevant process conditions for affecting biodiesel yield are investigated: methanol to oil ratio, catalyst concentration, reaction time and temperature. For the optimization study on biodiesel purification, five commonly used washing methods are also investigated: cold deionized water washing, hot deionized water washing, phosphoric acid washing, ultrasonic assisted washing, and magnesol washing. The optimization study, based on traditional mechanical stirring process, reveals that the decreasing ranking of significant factors for biodiesel production is catalyst concentration > reaction time > reaction temperature > methanol to oil ratio. The maximum biodiesel yield is found at a molar ratio of methanol to oil of 8:1, a reaction time of 70 min, a reaction temperature of 50℃, and a catalyst concentration of 1 wt.%. After testing the fuel properties of the final product, the optimized biodiesel meets the relevant requirements of the biodiesel standards and thus can be used as a qualified fuel for diesel engines. The optimization study, based on ultrasonic-assisted transesterification process, reveals that the maximal fatty acid methyl ester yield of the final biodiesel product is obtained under a methanol to oil molar ratio of 8:1, catalyst concentration of 1.25 wt.%, reaction time of 50 min and reaction temperature of 55 ℃. Compared with traditional mechanical stirring production process, ultrasonic-assisted transesterification process improves the biodiesel production since it could reduce the production cost and save energy. For the optimization study on biodiesel purification, the fatty acid methyl ester yield of the final biodiesel product, energy consumption and economic costs of different washing methods are compared. The comparisons indicate that the ultrasonic assisted washing method is the best method for biodiesel purification, when energy consumption and operation costs are considered. A preliminary kinetics study of transesterification reaction of camelina oil is carried out. After discussing four cases for overall reaction, a third-order reaction mechanism was proposed to fit the experimental data better because of the highest coefficient of determination. Based on the best-fit plot, the rate constants and activation energy are also determined. To sum up, the present research focuses on the optimization of biodiesel production and purification from camelina oil, and provides insights into the optimal process conditions for maximizing the biodiesel yield. Further research works are finally recommended to be continued. / published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

Thesis (M. A. Sc.)--Dalhousie University, 2005. / Includes bibliographical references (p. 104-108 of photocopy). Abstract and 24 page preview available online.

Submitted in complete fulfillment for the Degree of Master of Technology: Biotechnology, Durban University of Technology, Durban, South Africa, 2014. / Global warming is a major concern to the world’s population. It is caused by greenhouse gases that result from the burning of fossil fuel. The fossil fuel reserves are rapidly depleting as the needs and wants of man in the world increases. Biodiesel is one of the solutions proposed to remedy this environmental crisis facing the world today. The aim of this study was to characterise the biodiesel that can be produced from the oil of Litsea glutinosa by transesterification. Biodiesel can be used in a diesel engine without modification and be produced from many different natural renewable oil sources such as algae, plants and kitchen waste material. Jatropha curcas has been identified as a potential producer of oil for biodiesel. The biodiesel properties of Jatropha curcas meet the required American Society for Testing and Materials (ASTM) standards. The fruit of Jatropha curcas contains 40.0% lipids. The oil has a saponification number of 202.6 and an iodine value of 93.0. However Jatropha curcas cannot be grown in South Africa because it is a highly invasive plant. Cetane number is the most important parameter of biodiesel. The higher the cetane value, the better the quality of the biodiesel. Oil from Jatropha curcas has a cetane number of 57.1. An alternative is the oil from Litsea glutinosa, which is found as a naturalised free forest along the South African coastline, and is also found in many Asian countries. It has many medicinal properties, however, it is not edible and hence its use for biodiesel does not add to the debate of fuel versus food production. The cetane number of oil from Litsea glutinosa is 64.79, which is ideal for ignition, and the fruit with 61.29% lipids can yield valuable quantities of biodiesel. Thus, the aim of the research was to determine the potential of Litsea glutinosa as a source of biodiesel. Furthermore, to maintain a sustainable source, Litsea glutinosa was micropropagated, and transformation of Litsea glutinosa was attempted for hairy root cultures. The Clevenger apparatus was used to extract fatty acids from dried crushed fruit of Litsea glutinosa. Fatty acids were converted to fatty acid methyl esters by transesterification. Transesterification was conducted in the presence of nitrogen and the reaction was catalysed with a mixture of methanol and sodium hydroxide (NaOH). The ratio 1 : 3 of oil to catalyst mixture was used for optimum transesterification to ensure a forward reaction and it was transferred to a separating funnel to allow the glycerol and fatty acid methyl esters to separate. GC-MS was used to determine the fatty acids. The iodine number, saponification number, acid value, viscosity, kinematic viscosity, density, specific gravity, thermostability, distillation point and sulphur content were determined. The seeds of Litsea glutinosa were germinated and tissue culture callus was produced from the seeds and leaves. The leaves and stems were used to produce hairy root cultures by inoculating them with Agrobacterium rhizogenes. Litsea glutinosa yielded 61% oil, which included 47 fatty acids in the fruit and 24 fatty acids in the seeds. The fatty acid profile of the oils indicated that the predominant fatty acids present were those that are essential for good quality biodiesel. The dominant fatty acids found in the fruit were 65.4% 9-octadecenoic acid and 13.6% hexadecanoic acid. The dominating fatty acids found in the seeds contained 36.3% 9-octadecenoic acid, 13.9%, hexadecanoic acid and 39.1%, dodecanoic acid. The iodine value was 6.3. The saponification value was 274. The acid value was 0.45 mg KOH. g-1. The viscosity was 22.48 mm2. s-1 and the kinematic viscosity was 23.84 mm2. s-1. The density was 942.69 kg. m-3 and the specific gravity was found to be 0.9 g. cm-3. The distillation temperature ranged between 52.2°C to 610.2°C. The sulphur content was found to be 383 µg. ml-1. These characteristics indicate that Litsea glutinosa can be used as a source of biodiesel, because the properties meet the required ASTM standards. However, the production of biodiesel from Litsea glutinosa has not been commercialised because the production of fuel is dependent on the fruit of the plant, which is seasonal. To overcome this, a part of this study investigated micropragation of Litsea glutinosa and transformation of Litsea glutinosa by Agrobacterium rhizogenes into hairy roots and attempts where made to determine whether fatty acid could be produced by these techniques. Callus cultures were grown on MS media and McCowns woody plant media supplemented with 1 ml BAP and 1 ml 2,4-D per 1 L of media. Callus cultures were obtained in the light. However, Litsea glutinosa resisted transformation by Agrobacterium rhizogenes.

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on Jan. 22, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Process Control, Department of Chemical and Materials Engineering, University of Alberta. Includes bibliographical references.

Thesis (MTech. degree in Mechanical Engineering)--Tshwane University of Technology, 2010. / This study evaluates the use of biodiesel as an alternative fuel for diesel engines. The fuel properties, performance, emission characteristics and combustion characteristics of a four-stroke, four-cylinder water cooled, high speed direct injection (DI) diesel engine operated on biodiesel, 30% biodiesel and 70% biodiesel blended fuels were measured. Results related to the direct use of biodiesel as a diesel engine fuel indicate that this is possible but not preferable because of its high viscosity and cetane number. Biodiesel could be used in the blends with diesel fuel, because most of the measured properties of the biodiesel-diesel blended fuels were close to those of the diesel fuel. It was found that the performance parameters of the biodiesel-diesel blended fuels did not differ greatly from those of diesel fuel. A slight power decrease, with an increase in brake specific fuel consumption (BSFC), was noticed with the blend fuels. Smoke emissions were reduced for the blends while NOx was increased remarkably for the biodiesel-blended fuels. The test results demonstrated that the combustion carbon deposits (CCD) of biodiesel are a little less than that of the diesel fuel. The peak combustion pressure of the B70 blended fuel was found to be the highest amongst the four tested fuels. It is consequently argued that biodiesel appears to offer a potential alternative "greener" energy substitute for fossil fuel.

published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

No description available.

Thesis (M.S.)--Rochester Institute of Technology, 2008. / Typescript. Includes bibliographical references (leaves 155-159).