Journal of the Japan Institute of Energy
Online ISSN : 1882-6121
Print ISSN : 0916-8753
ISSN-L : 0916-8753
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Table of Contents
Special articles: Biomass (Original Paper)
  • Junya HIROTA, Masatoshi TODAKA, Tatsuya KON, Hitoshi SAIMA, Yasuhiro M ...
    Type: Original Paper
    2020 Volume 99 Issue 10 Pages 165-172
    Published: October 20, 2020
    Released: October 30, 2020
    JOURNALS FREE ACCESS

    Woody biomass is gasified with iron ore. The amounts of flammable gas products are not changed and only carbon dioxide are increased when iron ore exists. Iron ore in the residue of gasification reaction is almost reduced to metal iron. The amounts of tar and char are decreased at same time. Therefore, it is considered that iron ore is reduced by tar and char. When gasification of woody biomass is conducted under carbon dioxide atmosphere, the amount of carbon dioxide exhausted is lower than that of supplied. During gasification, carbon dioxide is reduced to carbon monoxide. This phenomena is important that this result means realization of negative emission. About 66% of iron ore is reduced to metal iron even under carbon dioxide atmosphere. More than 90% of energy of biomass is recovered when chemical potential of reduced metal iron is included.

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  • Teruaki YOKOO, Hisashi MIYAFUJI
    Type: Original Paper
    2020 Volume 99 Issue 10 Pages 173-181
    Published: October 20, 2020
    Released: October 30, 2020
    JOURNALS FREE ACCESS

    We investigate the reactivity and viscosity properties of macromolecules from wood such as cellulose and xylan in ionic liquids, which has ability to liquefy wood. The macromolecules from wood were treated with ionic liquids at 120 °C. The obtained ionic liquid insoluble residue was weighted and calculated yield of residue. We discussed for reactivity of the macromolecules from wood by changes of residual concentration with ionic liquid treatment. Viscosity measurements were performed for macromolecules from wood/ionic liquid solution. Huggins coefficient was calculated by resulting viscosity measurements. With Huggins coefficient we investigate state of macromolecules from wood in ionic liquids. It was assumed that cellulose would be dispersed in 1-ethyl-3-methylimidazolium chloride and would probably aggregate in 1-ethyl-3-methylimidazolium acetate. It was thought that the state of macromolecules from wood in ionic liquids influence on their reactivity in ionic liquids.

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  • Kosuke YAMAMOTO, Takaaki ASAO, Hiromasa NOJI, Tatsuhiko SAKAMOTO
    Type: Original Paper
    2020 Volume 99 Issue 10 Pages 182-189
    Published: October 20, 2020
    Released: October 30, 2020
    JOURNALS FREE ACCESS

    Promoting effective use of woody biomass as sustainable energy resource is essential. Woody biomass is generally traded by weight in the wood market, but timber is traded by volume in biomass use. In recent years, a power wholesaler and a fuel supplier tend to buy timber as woody biomass in the market, because the price of timber has been dropped. In order to evaluate disadvantages for the people engaged in forestry when trading low-price timber in the market, we investigated the underestimation of log volume and related issues at two wood markets in southern Mie prefecture. As a result, the lengths of all measured logs were evaluated as short. Moreover, the estimated volume of logs calculated by the Smalian’s formula based on measured values were 1.116 to 1.444 times higher than trading volume of logs in the markets.

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Special articles: Biomass (Technical Report)
  • Yan SUN, Yuta SUDO, Imron MASFURI, Novio VALENTINO, Atti SHOLIHAH, Rei ...
    Type: Technical Report
    2020 Volume 99 Issue 10 Pages 190-203
    Published: October 20, 2020
    Released: October 30, 2020
    JOURNALS FREE ACCESS

    In this study, the authors aimed to understand causal relationships between biomass gasification products yields and properties of clay catalysts based on results obtained by a lab-scale fluidized bed gasification of cellulose samples with nine types of clay particles collected in Indonesia. Factors affecting to the five products yields obtained by the experiments and the physical properties (11 types) of clay minerals were analyzed by a factor analysis to identify two common factors for experimental results and four common factors for clay properties. The correlation between the extracted factors for product yields and for clay properties was obtained by multiple regression analysis to show a good relationship between predicted and experimental data. A quantitative impact of each properties of clay catalysts to product yields was evaluated from correlation coefficients obtained by the multiple regression analysis. As comparisons of the impacts, specific surface area, potassium content and magnesium content had highest impact to produce gaseous species, on the other hand, weak acid content, total pore volume and average pore diameter had a highest impact to reduce tar production.

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Original Paper
  • Yue MORIIZUMI, Hiroki HONDO, Piyawan SRI-AMPAI
    Type: Original Paper
    2020 Volume 99 Issue 10 Pages 204-214
    Published: October 20, 2020
    Released: October 30, 2020
    JOURNALS FREE ACCESS

    The purpose of this study is to examine whether the introduction of solar drying systems contribute to the development of rural community activities in Thailand. In this study, interviews are conducted with six farmer groups who use solar drying systems for their production activities, and the empirical findings from the interviews are used as data for the analysis. The case analysis reveals that the introduction of solar drying systems has the potential to create the following three values. First, its introduction has the potential to motivate community members and bring out their initiative through the improvement of the working environment. The second is the possibility that its introduction may naturally induce learning to improve members’ competence, triggered by a change in drying methods. Third, its introduction has the potential to enhance the sustainability of local communities by strengthening ties within local communities and ensuring succession. More importantly, the use of renewable solar thermal energy realizes the three values mentioned above without the consumption of fossil fuels. This study suggests that the installation of solar drying systems may not only contribute to global environmental sustainability in terms of climate change mitigation, but also to the sustainable development of rural communities in developing countries.

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Technical Report
  • Pongsert SRIPROM, Pornyamon LEEPHISUTH, Arthit NERAMITTAGAPONG, Sutasi ...
    Type: Technical Report
    2020 Volume 99 Issue 10 Pages 215-219
    Published: October 20, 2020
    Released: October 30, 2020
    JOURNALS FREE ACCESS

    This work aimed to optimize lignin conversion to vanillin by hydrothermal method. An experiment was designed by Box-Benhken Design (BBD). Temperature, NaOH concentration, and reaction time were chosen as independent parameters for achieving the optimum reaction condition. The reaction products were analyzed by highperformance liquid chromatography. Based on the experimental results, the optimum condition for the hydrothermal process was predicted using the response surface method. The maximum vanillin production of 18.1 mg/L was predicted at the optimum condition given by the temperature of 142 °C, NaOH concentration of 9.2 g/L, and reaction time of 32 min. The conversion of lignin to vanillin was experimented using the predicted optimal condition to verify the prediction. It was found that the hydrothermal method at the optimum condition yielded 18.1 ± 2 mg/L of vanillin, which was in good agreement with the predicted value. It was also found that the yield of vanillin was influenced by temperature, NaOH concentration, and the interaction of both parameters, whereas the reaction time was much less influential.

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