Journal of the Japan Institute of Energy
Online ISSN : 1882-6121
Print ISSN : 0916-8753
ISSN-L : 0916-8753
Volume 97 , Issue 1
Showing 1-5 articles out of 5 articles from the selected issue
Table of Contents
Original Paper
  • Nami TAGAMI, Tomoe NAKADATE, Satoru MIZUNO, Tamio IDA
    2018 Volume 97 Issue 1 Pages 1-7
    Published: January 20, 2018
    Released: January 31, 2018

    This paper considers the possibility of applying indicators of coal as indicators of torrefied biomass characteristics. Used indicators of coal are fuel ratio which shows the combustion characteristics and coal band (van Krevelen diagram) which shows the degree of coalification. Torrefied biomass heated at different temperature are prepared by using green tea. Their changes of fuel ratio and chemical composition by coal band are considered. The results show the following findings. In the heating temperature from 293 K to 640K, fuel ratio is 0.38 to 2.07. There are the each negative correlation between yield of weight and fuel ratio when fuel ratios are a range of 0.38 to 0.65 and more than 0.65. When fuel ratio is 0.65, there is an inflection point. It is suggested that the volatile components released by thermal decomposition are different on the border line of the inflection point. By the application of coal band,chemical reactions are estimated during torrefaction process. However, it is difficult to decide what kind of reactions is occurring when the release of oxygen by decarboxylation and decarbonylation reaction and the release of hydrogen by demethanization and dehydrogenation reaction occur simultaneously.

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Technical Paper
  • Kentarou MORI, Takuya ITO, Yusuke KAKUTA
    2018 Volume 97 Issue 1 Pages 8-15
    Published: January 20, 2018
    Released: January 31, 2018

    Because the re-use of the solvent is difficult in solvent circulation type direct liquefaction process of woody biomass, the authors examined the possibility of solvent supply from plastic and the degradative behavior of the initial solvent under the condition of co-liquefaction of woody biomass and plastic. In the present study, Japanese cedar was used as woody biomass, polypropylene, polyethylene, and polystyrene, as model waste plastics and mineral oil as initial solvent. The effect of the reaction temperature on its performance and possibility of solvent circulation have been investigated and the following results were obtained. Because the decomposition of the mineral oil occurs in the reaction temperature higher than 400 °C because of the interaction with the biomass and plastics, that lower than 400 °C is preferable. The decomposition of plastics is promoted by the interaction caused by the co-liquefaction and yield of solvent fraction increases, excluding the polystyrene. Because the decomposition of the mineral oil occurred when the mineral oil was used as the initial solvent, the amount of solvent fraction was not sufficient after the reaction and the solvent circulation was difficult. It is expected that this problem can be solved by adjusting the polar compound fraction in the initial solvent.

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Technical Report
    2018 Volume 97 Issue 1 Pages 16-22
    Published: January 20, 2018
    Released: January 31, 2018

    This paper examines the relationship between economic growth (GDP per capita) and air pollution (CO2 emission per capita) in the Persian Gulf States based on the Environmental Kuznets Curve (EKC) hypothesis using regression analysis. First, the results provide weak support for the EKC hypothesis over the time series of data of 35 years from 1980 to 2014 spanning seven states. Instead, a positive linear relationship is suggested so that growth is associated with increasing emissions. Second, the factors underlying the rejection of the EKC hypothesis include institutional challenges for emission reduction such as (1) political restrictions, (2) soft budget constraints that are less-environmentally-friendly and (3) underdeveloped waste management, Third, weak support for the EKC hypothesis suggests opportunities for Japan to boost its international presence by participating in the Gulf States in decoupling economic growth from CO2 emissions.

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