M.S.

M.S.

Steam distillation is the most widely accepted process for the large scale production of volatile essential oils from herbaceous material and is also regarded as the standard practice throughout the flavour and fragrance industry. A mobile essential oil distillation unit for the extraction of oils from herbaceous materials would be extremely valuable to the essential oil industry in South Africa. Using a mobile platform, the extraction technology could be taken to rural areas where essential oil crops are grown in order to extract and then analyse the oils produced. Existing systems in South Africa are static distillation units which are usually owned by commercial growers that are generally positioned large distances away from the rural areas. The objective of this project was to design, construct and test a prototype mobile distillation unit for the extraction of essential oils from herbaceous materials. The unit was to have a charge vessel capacity of approximately 250 kg of plant material and should be able to perform in-field distillations in areas where electricity is not available. A literature review on all the essential oil extraction methods, the theory behind steam distillation and oil isolation and the effect that each of the distillation components have on the distillation process was performed. A small test distillation unit was set up in a laboratory in order to investigate the effects of varying steam flow . rates on the distillation time, oil yield and oil quality. A double charge vessel unit was designed, constructed and mounted onto a frame which in turn was fixed onto a trailer to be hauled by a light delivery vehicle (LDV). The steam generator with all its ancillary equipment was fixed onto a separate trailer. The unit could thus be easily transported and in-field distillations on various crops could be conducted. Field distillations were conducted with two crop types, namely rose geranium and lemon grass. Satisfactory results were obtained as the oil yields were within the expected oil yield range. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2005.

Thesis (S.M.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 49-50). / The focus of this thesis is the design and development of a system for rapid extraction of dissolved inorganic carbon from seawater and groundwater samples for radiocarbon dating. The Rapid Extraction of Dissolved Inorganic Carbon System (REDICS) consists of two subsystems - one for sample introduction, acidification, and carbon dioxide extraction, and one for carbon dioxide quantification and storing. The first subsystem efficiently extracts the dissolved inorganic carbon from the water sample in the form of carbon dioxide by utilizing a gas-permeable polymer membrane contractor. The second subsystem traps, quantifies and stores the extracted gas using cryogenics. The extracted carbon dioxide is further processed for stable and radiocarbon isotope analysis at the National Ocean Sciences Accelerator Mass Spectrometer Facility at the Woods Hole Oceanographic Institution. The REDICS system was tested using seawater standards collected at 470m and 4000m depth in the Atlantic Ocean and analyzing the extracted CO₂. The results were compared to the results for the same standards processed on the current NOSAMS water stripping line. The results demonstrate that the system successfully extracts more than 99% of the dissolved inorganic carbon in less than 20 minutes. Stable isotope and radiocarbon isotope analyses demonstrated system precision of 0.02%c and 3.5% respectively. / by Kalina Doneva Gospodinova. / S.M.