Ko Ko, Phyo Zin

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Preferred name
Ko Ko, Phyo Zin
Alternative Name
Koko, Phyozin
Koko, P.
Main Affiliation
Email
koko.ph@kmitl.ac.th

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    Item type:Publication,
    Impact of Engine Oil Additives on Nanostructure and Oxidation Kinetics of Diesel and Synthetic Biodiesel Particulate Matters using Electron Microscopy
    (2019-12-19)
    Koko, Phyozin
    ;
    Karin, Preechar
    ;
    Charoenphonphanich, Chinda
    ;
    Chollacoop, Nuwong
    ;
    Hanamura, Katsunori
    Physicochemical characteristics of particulate matters which are influenced by engine oil additives from engine combustion of diesel and synthetic biodiesel: Hydrotreated vegetable oil (HVO) were successfully investigated using electron microscopy, electron dispersive X-ray spectroscopy and thermogravimetric analysis. The agglomerate structure of diesel PM, HVO PM and diesel blending lubricant PM are similar in micro-scales. However, nanostructure of soot is a spherical shape composed of curve line crystallites while the metal oxide ash nanostructure is composed of parallel straight line hatch patterns. The oxidation kinetics of fuel blending lubricant PMs are higher than neat fuel PMs due to catalytic effect of incombustible metal additives from engine lubricating oil.
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    Physicochemical Characterization of Diesel Engine’s Soot and Metal Oxide Ash Nanoparticles Using Electron Microscopy, EDS and TGA
    (2021-06-01)
    Karin, Preechar
    ;
    Koko, Phyozin
    ;
    Charoenphonphanich, Chinda
    ;
    Chollacoop, Nuwong
    ;
    Hanamura, Katsunori
    Physicochemical characteristics of metal oxide ash derived from engine oil additives on particulate matter (PM) from a diesel direct injection compression ignition (DDI-CI) engine, in terms of nanostructure and oxidation kinetics, were investigated through electron microscopy, energy dispersive X-ray spectroscopy and isothermal thermogravimetric analysis. Diesel and synthetic biodiesel were used as the baseline fuel. Engine performance and combustion characteristics of neat diesel and synthetic biodiesel fuel were initially reported. To enhance the formation of ash derived from lubricant additives, an accelerated ash loading method was used by dosing 10% by mass directly into the fuels. Different single primary particle nanostructures of soot and metal oxide ash were clearly observed. Single primary particle nanostructure of soot was a spherical shape composed of curve line carbon crystallites, while nanostructure of metal oxide ash was a spherically round outline shape comprised with parallel straight-line lattice fringes. Soot oxidation kinetics was significantly enhanced due to the presence of metal oxide ashes in the engine’s PM. In addition, the elemental analysis of metal oxide ash, derived from engine oil additives, was investigated using electron dispersive X-ray spectroscopy.
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    Influence of Metal Oxide Ashes on Soot Oxidation Kinetics and Nanostructure using Electron Microscopy and Thermogravimetric Analysis
    (2019-04-09)
    Koko, P.
    ;
    Karin, P.
    ;
    Saenkhumvong, E.
    ;
    Charoenphonphanich, C.
    ;
    Phairote, W.
    According to increasingly stringent regulations on particulate emission from automotive vehicles, diesel engine must be equipped with Diesel Particulate Filter (DPF) to trap the Particulate Matter (PM) which are very harmful to human health. Diesel particulate matters are composed primarily of unburned hydrocarbon (soot) and metal oxide ashes as solid fraction. DPF can trap PM with higher filtration efficiency and the process which can burn the soot into carbon dioxide is called regeneration process. Although regeneration process can burn the soot effectively, incombustible ashes will be remained inside the DPF channel causing engine back pressure. These metal oxide ashes are mainly derived from lubricant additives, engine wear and trace metals from diesel fuel. In this article, different nanostructures of diesel soot and metal oxide ash derived by diesel blending lube oil condition were briefly compared using Transmission Electron Microscopy (TEM) image analysis. Electron Dispersive X-ray Spectroscopy (EDS) analysis was introduced to investigate the chemical composition of particulate matters. Thermogravimetric Analysis (TGA) was also conducted to compare the oxidation kinetics of pure diesel soot and the influence of metal oxide ash on soot oxidation kinetics. Contamination of metal oxide ashes promoted soot oxidation rate due to the presence of metallic additives from lube oil acting as a catalyst on soot oxidation kinetics.