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 14

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Physicochemical characteristics of ashes deposited on a wall flow diesel particulate filter of compression ignition engine
(2023-06-01)
Rodvanna, Sattatad
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Srilomsak, Mek
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Nuthong, Chaiwat
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Charoenphanich, Chinda
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Masomtob, Manop
The investigation of physicochemical characteristics of metal oxide ashes, deposited on a diesel particulate filter, was conducted using electron microscopy, energy dispersive spectroscopy, X-Ray fluorescence, and X-Ray diffractometry techniques. Iron is the main component of deposited ash on the DPF, and other ash components consisted of elements such as silicon, calcium, copper, sulfur, phosphorus, zinc, aluminum and minor chromium. It was clarified that this metal oxide ash has catalytic effect that contributed to an enhancement of soot oxidation. The apparent activation energies of soot oxidation on SiC powder and metal oxide ashes powder are approximately 169 and 135 kJ/mol, respectively.
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Physicochemical characterization of forest and sugarcane leaf combustion's particulate matters using electron microscopy, EDS, XRD and TGA
(2021-01-01)
Oo, Hay Mon
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Karin, Preechar
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Chollacoop, Nuwong
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Hanamura, Katsunori
Physical characteristics and quantitative elemental composition of PM and residual ash produced from sugarcane leaves (SCL) combustion were investigated using TEM-EDS compared with forest leaves (FRL). SEM-EDS was used to analyze the microstructure and chemical composition of biomass raw leaves and PM. XRD analysis was also performed to investigate the characterization of the crystalline nanostructure, structure of PM, and residual ash compared to the TEM image processing method. The oxidation kinetics of biomass raw materials, PM, and residual ash were investigated by TGA. The morphology of fine and ultrafine agglomerate structure of SCL soot and residual ash are not significantly different from the FRL soot and residual ash. The average diameter sizes of single primary nanoparticles of SCL and FRL soot are approximately 37 nm and 35 nm, while the sizes of residual ash are about 18 nm and 22 nm, respectively. The single primary nanoparticles of soot are mainly composed of curve line crystallites of carbon fringes, while residual ash is composed of straight-line lattice fringes. The average fringe lengths of SCL and FRL soot are about 1.25 nm and 1.04 nm from the outer shell and 0.89 nm and 0.74 nm from the inner core. The interlayer spacing of curve line carbon fringes of SCL and FRL soot is approximately 0.359 nm and 0.362 nm by the TEM image analysis and it was matched with XRD analysis. The biomass PMs are mainly composed of soot, Si, Ca, and K compounds: SiO<inf>2</inf>, CaCO<inf>3</inf>, and KCl.
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Oxidation Kinetics of Soot on Acicular Mullite Membrane Filter Using Electron Microscopy and Thermogravimetric Analysis
(2020-12-01)
Saenkhumvong, Eakkawut
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Karin, Preechar
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Charoenphonphanich, Chinda
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Vittayakorn, Naratip
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Hanamura, Katsunori
This paper investigates the oxidation kinetics of carbon black on acicular mullite using thermogravimetric (TGA) and mullite microstructures by scanning electron microscopy (SEM) for the development of diesel particulate filters (DPFs). It is observed that the amount of each chemical composition strongly affects the structure of mullite. The addition of AlF<inf>3</inf> and V<inf>2</inf>O<inf>5</inf> to mullite promotes the growth of needle-shaped mullite crystals. Thermogravimetric analysis was used to investigate and characterize chemical kinetics of soot oxidation for better understanding of designs and configurations of diesel particulate filters. The mass conversion of soot on the acicular mullite (ACM) is oxidized faster than that on the mullite (ML) membrane at all temperatures examined. The calculation of apparent activation energy (E<inf>a</inf>) of soot oxidation with isothermal methods on mullite was presented. The results showed that activation energy of soot oxidation is enhanced with ACM than with ML at all temperatures examined. The average calculated apparent activation energy of soot oxidation on ACM and ML are 146.4 kJ/mole and 155.3 kJ/mole, respectively.
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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
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Koko, Phyozin
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Charoenphonphanich, Chinda
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Chollacoop, Nuwong
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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 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
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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
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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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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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Effect of Metallic Microfiber Flow Through Diesel Particulate Filter System on Diesel Engine’s Particle Emission Physicochemical Characteristics
(2023-03-01)
Oh, Ban seok
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Thaeviriyakul, Poonnut
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Phairote, Watanyoo
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Srilomsak, Mek
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Charoenphonphanich, Chinda
It is well known that particulate matter (PM) from diesel compression ignition engines is harmful to the environment and to human health. To reduce engine PM emissions, exhaust after-treatment systems are utilized. A basic high-performance system can be composed of a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF). This study used a system composed of a DOC and a partial flow DPF. Partial flow refers to how only a portion of the exhaust gas is filtered using metal fibrous filters instead of the full flow using ceramic filters. The PM deposited on the side wall of the stages of the system was investigated with respect to elemental composition, morphology, and nanostructure. This was to determine the effect of each component on the PM. The elemental composition analysis found traces of the engine lubricant oil in the PM collected before entering the DOC. This was then eliminated by the DOC and the remaining PM was not significantly impacted by the exhaust after-treatment system. The morphology and nanostructure show an interesting relationship where the size of the single primary particles increased while the graphitic nature of the carbon in the PM seemed to decrease. This can be explained by the simultaneous nature of partial trapping and partial oxidation that occurs in the partial-flow DPF. The emission measurements of opacity, temperature, CO<inf>2</inf>, NO, and O<inf>2</inf> from each position also support this.
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Influence of Soot Contamination in API CI-4 Engine Oil on Four-Ball Metallic Wear Using Electron Microscopy Image Analysis
(2020-07-27)
Oungpakornkaew, Pitchaporn
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Rungsritanapaisan, Panyakorn
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Karin, Preechar
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Tongsri, Ruangdaj
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Tanprayoon, Dhritti
Engine lubricant has an important role in decreasing friction and the wearing of moving parts in the engine. However, soot contaminated in engine oil could change chemical and physical properties that affect the lubricant oil operation. Soot particles were simulated using carbon black in order to eliminate the effect of metallic ash and unburned hydrocarbon, which contained in particulate matter. The carbon black was blended in CI-4 lubricating oil. The investigation of metallic wear was associated with the use of a four-ball wear test. The amount of wear was compared by measuring the wear scar diameter of the worn surface on the steel balls. Scanning electron microscope (SEM) and confocal laser scanning microscopy were used for characterizing wear scar and surface roughness, respectively. In addition, the evidence of lubricant additive elements was detected on the wear surface by Energy Dispersive X-ray analysis (EDX). This research found that engine oil with soot contamination could lead to increasing amounts of abrasive wear by 83% and has approximately 1.1% larger wear scar diameter.
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Effect of a retrofitted metallic microfiber partial flow diesel particulate filter on a light duty diesel vehicle particle emission characteristics
(2024-02-01)
Mon Phyo, Mi Zwe
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Phairote, Watanyoo
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Srilomsak, Mek
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Charoenphonphanich, Chinda
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Masomtob, Manop
This study was conducted two distinct experiments, using a light-duty diesel vehicle at various engine speeds and loads as well as the new European driving cycle (NEDC) comparing commercial diesel fuel (B7) and pure biodiesel (B100). The NEDC involves a combination of urban and extra urban driving conditions. It aims to study a diesel vehicle's thermal efficiency as well as its gaseous and particulate matter (PM) emissions. This involves comparing results with and with no diesel oxidative catalyst (DOC) and a partial flow diesel particulate filter (PDPF) system. The surface morphology, micro- and nanostructure of a diesel vehicle's PM were also examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) to determine nanostructural and dimensional changes after mounting a DOC-PDPF system. Comparison of B7 and B100 combustion showed that B100 had around 1 % increase in brake thermal efficiency (BTE) at 1500 and 2000 rpm compared to B7 since B100 is a more oxygenated biofuel. At 2500 rpm, similar BTE values were observed. Introduction of a DOC-PDPF system resulted in an approximately 1 % BTE reduction for both fuels. This was due to greater friction losses caused by backpressure from the DOC-PDPF system. Increased exhaust backpressure was progressive, ranging from 1 kPa at idle speed to 6 kPa at high engine speeds for both tested fuels. The DOC-PDPF system respectively minimized PM emissions and particle numbers (PNs) by more than 50 % and 35 % for B7 and 71 % and 31 % for B100. These results are average values under the various phases of NEDC testing. A 30 % decrease in PM and a 44 % reduction in PNs under the overall test cycle were found when B100 was tested compared to B7. The soot primary particle size was reduced from 34.69 to 29.08 nm and the carbon fringe length diminished from 1.25 to 0.949 nm at different pre- and post-DOC-PDPF locations. This was due to partial oxidation on the surfaces of the PDPF metallic microstructure. PM undergoes simultaneous partial oxidation after passing through the DOC-PDPF system, as confirmed by TGA analysis.

Karin, Preechar

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