Journal of the Japan Institute of Energy
Online ISSN : 1882-6121
Print ISSN : 0916-8753
ISSN-L : 0916-8753
Volume 91, Issue 5
Displaying 1-3 of 3 articles from this issue
Original Paper
  • Tatsuya WAKEYAMA, Sachio EHARA
    2012 Volume 91 Issue 5 Pages 391-404
    Published: 2012
    Released on J-STAGE: May 31, 2012
    JOURNAL FREE ACCESS
    The present work is intended to evaluate renewable energy resource potential with common criteria based on spatial data. It is necessary for the world to promote renewable energy use from the view point of reducing greenhouse gas emissions. Evaluation of renewable energy potential is important in order to construct renewable energy facilities efficiently. The authors developed a new method for the renewable energy potential evaluation in large scale with the aid of Geographic Information System. This new method consists of three processes. The first process is simulation of the meteorological parameters such as river discharge and direct solar radiation. The second process is extraction of potential areas with restrictions according to climate conditions, geographical features and social environment. The third process is calculation of annual energy production on the condition that the extracted potential area is filled with renewable energy facilities as much as possible. The application of the new method to Kyushu area shows that Kyushu area has 35,728 GWh/year of wind power potential, 28,283 GWh/year of mini-micro hydropower potential, 2,404 GWh/year of solar power potential.
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  • Moritoshi MITANI, Gento MOGI
    2012 Volume 91 Issue 5 Pages 405-416
    Published: 2012
    Released on J-STAGE: May 31, 2012
    JOURNAL FREE ACCESS
    Bio-transportation methanol production chain, from feedstock harvest, pre-treatment (drying), to transportation to conversion plant was evaluated from energy perspective. "Economy of scale" of the methanol conversion plant versus transportation cost, which increases due to the increased average distance required to transport their increased feedstock volume, was also schematically evaluated. Since energy feedstock become available in autumn in most cases and the maximum period of time for feedstock collection is some 6 months, and the feedstock distributes in wide area and feedstock is bulky due to its low density nature, to bring feedstock to methanol conversion plant on a constant basis require well designed logistics strategy. How to handle large volume seasonal feedstock piles might be the largest issue involved in this area. It turned out that the whole operation may require up to 40% of feedstock's original energy (equivalent), and the main components of which include biomass drying for pelletization being up to 17% and drying in the methanol plant being 2 to 10%, and long distance shipment, 13 to 21%, among others. Yet still, a unit of 100 million ha of land might fuel some 180 million methanol fueled fuel cell vehicles, which is likely to be feasible in the future, even with 40% maximum total loss.
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  • Miki SHIMOGORI, Toshihiko MINE, Noriyuki OHYATSU, Noboru TAKARAYAMA, Y ...
    2012 Volume 91 Issue 5 Pages 417-424
    Published: 2012
    Released on J-STAGE: May 31, 2012
    JOURNAL FREE ACCESS
    To obtain practical knowledge in operating soot-blowers without ash related problems, a series of slagging tests have been conducted at 1.5 MWth pilot plant and the rates of decreasing heat fluxes through the test probe simulating the water-wall have been determined. In this study, initial heat flux, this heat flux decreasing rate, and the heat flux at which decreasing heat flux rate is reduced are employed to predict the soot blowing time. A simple equation is obtained for predicting the soot blowing timing. Discussion is made on the derivation of the equation, and it is expected that the derived equation holds for any furnace.
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