Journal of the Japan Institute of Energy
Online ISSN : 1882-6121
Print ISSN : 0916-8753
ISSN-L : 0916-8753
Current issue
Displaying 1-7 of 7 articles from this issue
Table of Contents
Special articles: JCREN III (Original Paper)
  • Rawit JITTHAM, Niracha WONGDEE, Pritsana THAMDEE, Nontipa SUPANCHAIYAM ...
    Article type: Original Paper
    2022 Volume 101 Issue 12 Pages 235-241
    Published: December 20, 2022
    Released on J-STAGE: December 28, 2022
    JOURNAL FREE ACCESS

    Carbon-silica composites with mesoporous structures were synthesized from low-cost materials by conventional heating. The carbon source used was vinasse, a by-product of ethanol production from molasses, while Na2SiO3 and K2SiO3 were utilized as low cost and abundantly available silica sources as alternatives to tetraethyl orthosilicate (TEOS). The simple preparation method was adopted as follows: vinasse was dehydrated with 50% H2SO4 (1:2 in weight ratio) to produce carbon, after which the silica source was added with weight ratio of vinasse:silica source 0.8:1, 0.2:1 and 0.5:1 for Na2SiO3, K2SiO3 and TEOS, respectively. The mixture was stirred and heated at 80 °C for 6 h, washed with water, and dried at 120 °C for 3 h to obtain the carbon-silica composites. Composites were characterized by N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), moisture content, ash content, slurry pH, point of zero charge (pHPZC) and bulk density. The composites exhibited BET (Brunauer–Emmett–Teller) surface areas of 443, 354 and 570 m2/g and average pore diameters of 5.20, 5.52 and 7.63 nm when using Na2SiO3, K2SiO3 and TEOS, respectively, as silica sources. The carbon-silica composites were highly mesoporous, accounting for around 71-80% of the total volume. FTIR analysis showed the presence of Si–O–Si bond for all composites. According to TGA results, the adsorbents were thermally stable up to 700 °C. The slurry pH and pHPZC of each composite was very similar with acidic character (slurry pH 2.63–6.80 and pHPZC 2.95–7.00). The bulk density of composites was 560–660 kg/m3, higher than some commercial activated carbons. These results indicated that the mesoporous carbon-silica composites prepared from vinasse and low-cost silica sources were promising functional materials for use as potential adsorbents.

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Special articles: JCREN III (Technical Paper)
  • Wasan CHOKELARB, Pornsawan ASSAWASAENGRAT, Andy SITTON, Thanant SIRISI ...
    Article type: Technical Paper
    2022 Volume 101 Issue 12 Pages 242-250
    Published: December 20, 2022
    Released on J-STAGE: December 28, 2022
    JOURNAL FREE ACCESS

    Varnish problems in turbine oil of power plants in Thailand are still an issue today. The problems are the coefficient of friction of the oil will increase along with the increase in varnish concentration and varnish deposits. This creates problems in starting/re-starting of the turbine. Even with the advent of oil manufacturing research to improve base oil quality and antioxidant additive, varnish contamination starting problems have been one of the most concerning problems for maintenance. The most recent version of ASTM D4378-20 suggests that maintenance personnel should test their in-service turbine oil and monitor the membrane patch colorimetry with a warning limit at ∆E 30. This monitoring test is known as ASTM D7843-20 Standard Test Method for Measurement of Lubricant Generated Insoluble Color Bodies in In-Service Turbine Oils using Membrane Patch Colorimetry (MPC). This study introduces the monitoring of soluble color bodies, in addition to the insoluble, at the same time. Focusing only on the value of insoluble-MPC test can sometimes be misleading and may cause inaccurate and ineffective maintenance decisions. In this paper, both soluble and insoluble color body analytical results from in-service gas turbine oils will be presented. Three power plants were monitored for both soluble and insoluble varnish. It will show how the use of a combination of soluble and insoluble color body assessments of the turbine oils would further improve the oil diagnostic services of turbine lubricants by providing insights into the capability of the lubricants to solubilize the oxidation by-products of the antioxidants and the highly refined base oil. Appropriate varnish removal technologies were also decided and applied to respond proactively to the varnish issues.

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  • Jay Carlo S. AGUILAR, Chosel P. LAWAGON
    Article type: Technical Paper
    2022 Volume 101 Issue 12 Pages 251-257
    Published: December 20, 2022
    Released on J-STAGE: December 28, 2022
    JOURNAL FREE ACCESS

    Medium-density fiberboard (MDF) was developed from Durio zibethinus (durian) husk using urea formaldehyde (UF) as binder. The output will be applied as an automotive panel, realigning the conventional application of MDFs. Fibers were recovered from the husk, the undersize of 10 mesh screen was used for board production. The optimal conditions were determined by different mixing ratios of UF with water and varying the pressing pressure. The undersized fibers and optimized board were characterized in terms of surface morphology. Moreover, the mechanical properties of fiberboards were also studied. Results showed that fiberboard was optimal at a press pressure of 640 kPa. It yielded an internal bond (IB) of 2.85±0.43 MPa, modulus of elasticity (MOE) of 3008±228.69 MPa, and modulus of rupture (MOR) of 22.25±2.61 MPa. These were compared against properties of commercial MDF based on American National Standards Institute (ANSI) specifications (IB≥0.6 MPa, MOE≥2500 MPa, and MOR≥22 MPa). Hence, these results proved that the optimized fiberboard has high potential for commercial application in the automotive industry.

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Special articles: Asian Conference on Biomass Science (Original Paper)
  • Masato KOUZU, Katsuyuki MORI, Minato KOJIMA, Haruka ISHIDA, Monique Jo ...
    Article type: Original Paper
    2022 Volume 101 Issue 12 Pages 258-264
    Published: December 20, 2022
    Released on J-STAGE: December 28, 2022
    JOURNAL FREE ACCESS

    For targeting the simultaneous production and storage of the renewable hydrogen, aqueous phase reforming (APR) of glucose as the model saccharide was tested in the presence of cresol. Assuming that cresol functions as the hydrogen acceptor, the produced hydrogen is not only prevented from being wasted by the side reactions of the glucose APR, but also carried easily anywhere. Additionally, there is a possibility that the lignin-derived phenolic compounds can be utilized as the hydrogen acceptor. In the present research work, the test reaction was catalyzed by the Pt supported on alumina at the reaction temperature ranging from 493 K to 553 K. Also, the cresol free test reaction was carried out for verifying our research originality to promote the production of the renewable hydrogen.

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Special articles: Asian Conference on Biomass Science (Technical Paper)
  • Fumio HASEGAWA, Shingo YOSHIKAWA, Kenichi FURUHASHI, Yutaka KAIZU, Ken ...
    Article type: Technical Paper
    2022 Volume 101 Issue 12 Pages 265-269
    Published: December 20, 2022
    Released on J-STAGE: December 28, 2022
    JOURNAL FREE ACCESS

    In this study, the vegetation status of Erianthus using unmanned-aerial-vehicle (UAV) photogram-metry integrated with structure from motion (SfM) was investigated. When estimating the height of Erianthus, the values estimated using the UAV-SfM method were slightly smaller than the measured value because of the difficulty in matching leaf tips in aerial images. However, the height could be estimated with a determination coefficient of 0.95 or more at altitudes of 50 m, 50 m + diagonal, and 100 m. It was revealed that the UAV-SfM method is suitable for estimating the Erianthus height, and aerial shooting at an altitude of 100 m is sufficiently accurate.

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