Browsing by Author "Kassa, Adane"

Now showing 1 - 1 of 1
  • No Thumbnail Available
    Item
    Investigation of Parabolic Dish Solar Concentrator for Local Areke Distillation
    (Addis Ababa University, 2015-03) Kassa, Adane; Alemu, Demiss (PhD)
    Areke is Ethiopian’s locally produced traditional fermented alcoholic liquor which is produced from difedif- mixture of milled gesho (Rhamnus Prinoides), finely ground and cooked/baked cereals, and water left for fermentation for nine to ten days, by the of process distillation. The heat required for the distillation process is obtained from burning firewood on inefficient three stone stoves. Energy inefficiency, greenhouse gas emission to the environment, human respiratory system diseases and deteriorating household economy are the major negative impacts that resulted from using biomass as energy source for local areke distillation. This thesis work presents the design and manufacturing of parabolic dish solar collector system for local areke distillation process as a substitute energy source instead of burning biomass and reports the test results of the system. In order to show design procedure; parabolic dish solar collector system with aperture diameter of 1.6m, depth of 0.4m and focal length of 0.4m was designed in full scale. The parabolic dish is designed for distillation of 24 liters of difedif to obtain 3 liters of areke with alcohol content of 44% per day (i.e. from 8:00AM to 5:00PM). One cycle of distillation takes on average 3 hours to obtain 1 liter of areke from 8 liters of difedif. However, the parabolic dish frame of aperture diameter of 1.2m, depth of 0.3m and focal length of 0.3m, which already exists in AAIT Mechanical workshop, with a little maintenance and modification was used for the test purpose. Aluminum foil laminated galvanized sheet is used as reflective surface for dish concentrator. The parabolic dish tracks the sun ray manually based on the shadow of pin on the edge of dish aperture. Especially made clay pot with capacity of 4 liters, and having effective surface area of 0.071m2 was used as absorber. 2.5 liters of difedif was used to conduct the test in three different days. The test result showed it was possible to obtain from 2.5 liters of difedif 0.25liters of areke with alcohol content of 44% and on the average it took 3 hours. And on average it took 1 hour and 15minutes to reach temperature of 70.4oC which is the boiling point temperature of alcohol in Addis Ababa at atmospheric pressure of 0.746atm, where the test was conducted. So, with appropriate design of solar energy distiller system for local areke distillation as an alternative source of energy showed promising results and has the potential to mitigate the negative impacts related to traditional areke distillation method.