Karin, Preechar

Preferred name

Karin, Preechar

Alternative Name

Karin, P.

Karin, Preecha

Main Affiliation

School of Engineering

preechar.ka@kmitl.ac.th

Now showing 1 - 10 of 63

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CHARACTERIZATION OF PARTICULATE MATTERS EMITTED FROM BIOMASS COMBUSTION USING ELECTRON MICROSCOPY AND ENERGY DISPERSIVE X-RAY SPECTROSCOPY
(2020-01-01)
Mon Oo, H.
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Karin, P.
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Masomtob, M.
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Saisirirat, P.
;
Chollacoop, N.
Particulate Matters (PMs) emitted from biomass combustion including open burning of biomass agricultural residues, and forest fires must be reduced to protect both human health and the environment. The physical characteristics of morphology, elemental composition and nanostructure of particulate matters generated from biomass combustion were successfully investigated by using electron microscopy and energy dispersive X-ray spectroscopy (EDS) analysis with Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), and thermogravimetric analysis (TGA) was used to analyze the oxidation kinetics of particulate matters. Before biomass burning, it was found that about 65% of carbon fraction in biomass raw material while 95% of carbon fraction in soot and 84% in ash particles after burning. The average diameter size of single primary particles is approximately 36 nm. Nanostructure of the single primary particle of biomass soot is mainly composed of curve line carbon crystallites while metallic ash nanoparticle is composed of straight-line hatch patterns. The inter-planar spacing of fringes of biomass soot and ash crystallites is 0.36 nm and 0.28 nm, respectively. This article aims to study the different nanostructure of biomass forest leaves residual ash and soot such as agglomerated particles, primary particle's measurement using TEM image analysis.
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Physical characterization of biodiesel particle emission by electron microscopy
(2013-01-01)
Karin, Preechar
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Songsaengchan, Yutthana
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Laosuwan, Songtam
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Charoenphonphanich, Chinda
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Chollacoop, Nuwong
Nanostructures of diesel and biodiesel engine particulate matters (PMs) were investigated by using a Transmission Electron Microscopy (TEM). The average single particle sizes of biodiesel and diesel PMs are approximately 30-40 nm and 50-60 nm, respectively. Image processing process was used to estimate each carbon platelet length by using TEM image. The average carbon platelet length of biodiesel and diesel PMs are in the range of 0.1-7.0 nm. Moreover, carbon atoms per cubic volume of PMs are approximately 500-900. The result shows that engine load and fuel property are strongly impact on the size of single particle and carbon atom density of particle. This is one of interesting behaviors need to be investigated for better understanding. The results of this research would be used as basic information for design and develop removing process of PM emitted from engine combustion which using in diesel and biodiesel fuels. © Copyright @2013 SAE Japan and Copyright @ 2013 SAE International.
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Influence of V2O5 and AlF3 on Microstructure of Acicular Mullite Diesel Particulate Filter Along with Soot Oxidation Kinetics
(2021-12-01)
Saenkhumvong, Eakkawut
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Karin, Preechar
;
Win, Swe Zin
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Sirivarocha, Settavit
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Chollacoop, Nuwong
In current research, aluminium oxide and silicon dioxide are used as raw materials for fabricating main structures of mullite diesel particulate filters. The variable substances applied to develop acicular mullite structure are titanium dioxide, aluminium fluoride, and vanadium oxide. Carbon black was used to create pores in mullite diesel particulate filters with 35 to 45% porosity based on the sintering temperature of 1300°C. The images of the filter’s porous surface microstructure were investigated using scanning electron microscopy. Vanadium oxide and aluminium fluoride play important roles in growth of acicular shape and acicular size for membrane, respectively. Acicular size of membrane varies from a hundred nano-meters to the submicron in needle diameter. The relation of all factors between pore size, porosity, surface roughness, and pin-shape microstructure can be controlled by additional amounts of additives. From Raman spectroscopy analysis, the soot formation of carbon black’s micro and nanostructure are acceptable to simulate diesel soot particles. In line with these results, carbon black was successfully used as a substitute of real engine soot in soot kinetics reactivity. In addition, the oxidation kinetics of soot particles on mullite and acicular mullite membrane were investigated by using tight contact in isothermal and loose contact in non-isothermal thermo-gravimetric analysis. The calculated apparent activation energies of soot oxidation with isothermal technique on mullite and acicular mullite membrane are approximately 213 and 141 kJ/mol while those values calculated with non-isothermal technique are 118 and 76 kJ/mol, respectively.
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Physicochemical characterization of direct injection Engines's soot using TEM, EDS, X-ray diffraction and TGA
(2021-06-01)
Oo, Hay Mon
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Karin, Preechar
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Charoenphonphanich, Chinda
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Chollacoop, Nuwong
;
Hanamura, Katsunori
The physical characteristics and elemental composition of particulate matters (PMs) from gasoline direct injection spark ignition (GDI-SI) engines were successfully investigated using transmission electron microscopy - energy dispersive X-ray spectroscopy (TEM-EDS). Thermogravimetric analysis (TGA) was used to analyze the PMs oxidation. The morphology of agglomerated GDI-PMs is not significantly different from the diesel direct injection compression ignition (DDI-CI) engine's PMs. The spherical single primary nanoparticles of the engine's soot composed of curve line carbon crystallites. The average diameter size of the single primary nanoparticles of GDI, DDI, and carbon black are approximately 24 nm, 26 nm, and 31 nm, while the inter-planar spacing is about 0.364 nm, 0.358 nm, and 0.356 nm, respectively. The total fringe lengths of GDI, DDI, and carbon black are approximately 154 nm, 159 nm, and 163 nm measured from the areas of 10 nm × 10 nm inner core regions of primary nanoparticles, and are 180 nm, 195 nm, and 228 nm from the outer shell regions, respectively. The total fringe lengths of inner core are shorter than the outer shell. Besides, the engine's PMs contains both crystalline and amorphous carbon structure using XRD analysis. The GDI-PMs had the least crystalline structure compared to the DDI-PMs and carbon black due to the higher percentage of amorphous fraction. TGA analysis showed that the GDI-PMs oxidation was faster than the DDI-PMs and CB-N330 oxidation because of the primary particle size, the fringe length, and the crystal size which have an impact on oxidation kinetics of particulate matters.
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Experimental investigation of the impact ethanol-biodiesel-diesel blended fuels on combustion, emission, and performance of compression ignition diesel engine
(2022-01-01)
Wai, P.
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Karin, P.
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Phairote, W.
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Chollacoop, N.
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Kosaka, H.
This research was directed to reduce the global diesel engine emissions and dependency on finite fossil fuel reserves. The ethanol was blended by weight ratio with commercial “B20” fuel (20% palm oil's biodiesel and 80% diesel) as B20E5 (95% B20 with 5% ethanol), B20E10 (90% B20 with 10% ethanol) and B20E20 (80% B20 with 20% ethanol). The results of the engine's performance, combustion, emission, and agglomerate particles size using blended fuels were compared with the results of based commercial B20 fuel. All fuel samples were tested on a four-cylinder direct injection diesel engine at a constant load of 140Nm with engine speeds of 1000RPM, 1500RPM and 2000RPM. When the engine speed increased, the brake-specific fuel consumption decreased, and the brake thermal efficiency increased. The B20E20 shows the highest brake-specific fuel consumption because of the low energy content of the fuel blend and the highest thermal efficiency because of a better combustion process. The ethanol-blended fuels show higher peaks of in-cylinder pressure and heat release rate than the base B20 fuel, with B20E20 as the highest. Ethanol blended fuels have significant advantages in particulate matters reduction, especially in idle engine speed. The blended fuels decreased soot and CO<inf>2</inf> emissions and increased NO<inf>x</inf> emission. The agglomerate particles size distribution was analysed with 100 samples for each fuel by using Scanning Electron Microscopy (SEM) and Image J tools. The average agglomerate particle size of B20, B20E5, B20E10 and B20E20 are 0.253 µm, 0.245 µm, 0.225 µm and 0.187 µm, respectively. As conclusion, adding ethanol to diesel fuel provide strong advantages on soot reduction and higher engine efficiency due to the enrich of fuel oxygen.
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Effect of Soot Particle Size on Four Ball Metallic Wear Using Electron Microscopy Image Analysis
(2020-06-01)
Karin, Preechar
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Amornprapa, Warawut
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Watanawongskorn, Park
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Saenkhumvong, Eakkawut
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Charoenphonphanich, Chinda
The impact of soot primary nanoparticles affecting metal wear was investigated. The commercial Carbon Black (CB) with different primary particle sizes were mixed with the engine oil for simulating soot contamination. The physical properties of carbon black including density and hardness were calculated using Transmission Electron Microscopy (TEM) image analysis. The metallic wear test was evaluated by using a Four-ball wear tester. After the tests, the ball surfaces were inspected by utilizing High-Resolution Optical Microscope (OM), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX) analysis. Based on a Four-ball wear test, the 1 % by weight of carbon black contamination shows a bit higher average wear scar diameter (WSD), but the surface roughness is reduced. SEM micrograph of metallic wear scar for the engine oil without soot shows the area of grooves, plastic deformation and subsurface crack. On the other hand, when carbon black is added to the oil, it can be seen that there are many deep grooves along with the sliding direction. The relationship of calculated oil film thickness, primary nanoparticle size distribution, carbon atom density of soot and hardness is clearly explained metallic wear mechanisms.
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Battery sizing for electric vehicles based on real driving pattern in Thailand
(2018-01-01)
Duangsrikaew, B.
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Mongkoltanatas, J.
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Karin, P.
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Hanamura, K.
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Benyajati, C.
The purpose of this study was to carry out a battery sizing based on the fulfilment of power requirement from the representative real driving pattern in Thailand. The real driving cycle data i.e. velocity and vehicle global position were collected through a GPS-based equipment, VBOX. The driving data transportation services provided in a campus of university based in the rural area of Bangkok were collected from three different types of i.e. closed-area, inter-city and local feed. Three campus driving data types were gathered to achieve a suitable dimensioning of battery systems for electrified university public buses.
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Spray visualization of biodiesel and diesel in a high pressure chamber
(2014-01-01)
Srichai, Prathan
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Chareonphonphanich, Chinda
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Karin, Preechar
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Chollacoop, Nuwong
The present research attempted to characterize fuel spray pattern, such as spray angle, spray penetration and their mixture formation by recourse to images analysis. Diesel and biodiesel were used to investigate via a single hole injector (solinoild type) in a constant volume high-pressure chamber. In this experimental study, the spray characteristics of diesel and biodiesel fuel were comparatively evaluated. Initial conditions were ambient temperature, ambient density of 21 kg/m<sup>3</sup>, injection durations varied from 0.5 and 1 ms and rail pressure of 400 and 800 bar. The series of images were captured by high speed video camera with resolution of 7,500 frames per second and shutter speed of 1/10,000 sec under Schlieren photography technique. The result showed the biodiesel spray penetration was longer than that of the diesel, and spray angle of biodiesel in start injection was larger than biodiesel. From the results, it can be concluded that the higher the density and viscosity of biodiesel, the stronger the effect on the spray mixture formation. © (2014) Trans Tech Publications, Switzerland.
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Physicomechanical Characteristics of Carbon Fiber Reinforced Polymer Composite Using X-Ray Diffraction, Atomic Force and Electron Microscopies
(2022-10-01)
Lin, Ye Htet
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Karin, Preechar
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Larpsuriyakul, Patcharee
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Ohtake, Naoto
The physicomechanical characteristics of PAN-based carbon fibers were investigated by SEM-EDS, XRD, TEM and AFM analysis while the mechanical properties of the composites were studied by tensile, flexural and Charpy impact tests with ASTM standards. Regarding the tensile test of carbon fiber fabric, the average tensile strength of CF-I, CF-II and CF-III fibers were around 147 MPa, 137 MPa and 225 MPa and the tensile modulus of those were 12.8 GPa, 13.2 GPa and 12.8 GPa, respectively. Later, the nanostructure of carbon fiber was recognized not as a pure graphite carbon structure because they mixed with graphite and amorphous structures. The higher tensile strength and modulus of CF-III fiber fabric was lower interlayer spacing (d002) because it consisted of more graphene layers in the graphite structure when compared with CF-I and CF-II fiber fabrics. Concerning AFM analysis’s results, CF-I fiber fabric has higher surface roughness (Ra) of 34.8 nm and more in-depth with wider pit lines along the fiber axis, which caused higher mechanical properties among the three composites. According to this article, the nanostructure of carbon fibers had a lower impact on CFRP composite because the interfacial bonding between fiber and epoxy matrix, which obtained the higher mechanical properties in the composite, was directly enhanced by the higher surface roughness of the fibers.
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Oxidation kinetics of small CI engine’s biodiesel particulate matter
(2015-04-01)
Karin, P.
;
Borhanipour, M.
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Songsaengchan, Y.
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Laosuwan, S.
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Charoenphonphanich, C.
Particulate matters (PMs) oxidation kinetics by Thermo-gravimetric analysis (TGA) was successfully studied. The chemical content percentage of PM can be divided by oxidation temperature zoning in three main regions which are moisture, unburned hydrocarbon (HC) and carbon. It is clearly observed that the amount of each region is strongly depending on engine operating condition, the amount of unburned HC in low load condition of the engine load are larger than that of high load condition. The calculated apparent activation energies of biodiesel PM oxidation are lower than that of diesel PM and carbon black because of unburned oxygenated molecule. The calculated apparent activation energy of biodiesel and diesel PMs oxidize with air is in the range of 147–157 kJ/mole and 153–165 kJ/mole, respectively. The results of this research would be used as basic information for design and develop removing process of particulate matter emitted from engine combustion which using in diesel and biodiesel fuels.

Karin, Preechar

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