Journal of the Japan Institute of Energy
Online ISSN : 1882-6121
Print ISSN : 0916-8753
ISSN-L : 0916-8753
Volume 88 , Issue 11
Showing 1-3 articles out of 3 articles from the selected issue
Original Paper
  • Yasuhiko KONDOU, Akinobu MURATA, Kimiko YAMADA, SAKAMOTO SAKAMOTO, Wei ...
    2009 Volume 88 Issue 11 Pages 994-1001
    Published: 2009
    Released: December 09, 2009
    A large amount of energy is expended for heating in Northern China, especially in rural areas, to keep out the bitter cold in the long winter season. The amount of energy necessary for heating must have been correctly estimated before total heating energy consumption can be reduced. However, it is difficult to estimate accurately each of cooking and heating energy consumptions of rural households in China; they mainly use one of traditional types of stoves called Kang and Zilu both for cooking and heating. The objective of this study is to provide descriptive information on cooking and heating energy consumptions of rural households living in three provinces in Northern China. To achieve this objective, we conducted a questionnaire survey on energy consumption and collected the answers from the responders to estimate only the cooking energy consumption for each household. Our study shows noteworthy results in that the approximate annual total of energy consumption could be estimated for each of cooking and heating energy consumptions. However, unlike in developed countries, no correlation was observed between the heating energy consumptions and the floor spaces in these rural households.
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  • Yoichi SHIMAZAKI, Katsuhiko NAGASAKA, Takumi ONDA, Masayuki OZAWA
    2009 Volume 88 Issue 11 Pages 1002-1008
    Published: 2009
    Released: December 09, 2009
    This study analyzes the energy balance of bio-ethanol production from agricultural residue biomass in Chuo City. A specially valued local product of this area, located in central southern Yamanashi Prefecture, is sweet corn. Sweet corn production can be useful for solving both food scarcity and energy-resource depletion problems. The second crop in idle fields, sorghum, is examined based on its climatic properties. Herein, we propose a simple format to produce ethanol from juice liquid sugars of both crops. Calculation of the energy balance is classified in terms of cultivation, collection, transport, and production. Results show that the potential ethanol production of Chuo City is 667 kiloliters. Bio-ethanol can be a renewable fuel for transportation that is sufficient to replace the use of gasoline in Chuo City's Office functions. Calculation results suggest that the energy balance is from 0.643 to 0.717. Reduction of fossil fuel consumption during production processes is important. In this study, five cases are investigated to calculate a unit price. The production unit price is 350 yen per liter in this city, which can be decreased to 208 yen per liter with increased plant operation days from 100 to 300 days annually. It would thereby be necessary to collect other agricultural residue biomass and to expand the collection area to achieve unit price reduction. Methane emissions from rice fields could be reduced by half by switching fuels to those produced from sweet corn residues. Results of these studies underscore the useful role of bio-ethanol production for communities of the future.
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Short Paper
  • Junichiro ODA, Keigo AKIMOTO
    2009 Volume 88 Issue 11 Pages 1009-1016
    Published: 2009
    Released: December 09, 2009
    The steel production in China has rapidly increased since 2000. India also would strengthen their capability of steel production in the early stage. Under the situations, the improvement of energy efficiency in the steel sector is one of the most important measures for mitigating climate change. The global communities are now recognizing that "sectoral approach" will strongly support the diffusion of energy efficient technologies. The "sectoral approach" can be one of the effective frameworks after 2013; however, comparable indicators of energy efficiency among global countries/regions are needed for the discussion of the framework. This paper evaluates regional energy efficiency in iron and steel-making sector, i.e., energy consumption per ton of crude steel production. IEA indicates that there are some issues, e.g., system boundary, allocation, and data availability, for directly estimating regional energy efficiency under current IEA statistics status. This study overcomes these issues by using many sources and multistage frameworks. The estimated regional energy efficiency is useful and essential to discuss concrete measures for energy efficiency improvement in the global iron and steel sector.
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