• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.359-365
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• 1999

We have evaluated the performance and some physical properties of 25 automotive engine oils (21 domestic and 5 imported products) which are purchased on the market to verify the API(American Petroleum Institute) or ILSAC(International Lubricant Standardization and Approval Committee) certification marks attached on the products and to determine the necessity of the quality control of the engine oils on the market. 12 test items are chosen according to API engine oil specification, which are flash point, pour point, cold cranking simulator apparent viscosity, pumping viscosity, gelation index, HTHS(High Temperature High Shear viscosity), foam, high temperature foam, filterability, volatility, high temperature deposit(TEOST), phosphorus content. We have found one product which did not meet the API specification on gelation index, one on HTHS, four on foam, and one on volatility, which implies that the quality control system is in need to check the fidelity of the certification marks attached on the engine oils being marketed. In addition, this works raises the necessity of the upgrade of the present Korean engine oil specification.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.495-503
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• 2017

Wax components can be precipitated when surrounding temperature decreases below wax precipitation temperature (WAT). WAT as well as pour point are important characteristics to evaluate the behavior of waxy oils. In this study, qualitative and quantitative evaluations of waxes in waxy model oils were presented after determining WAT and pour point. In case of anhydrous waxy model oils, ASTM D2500 may be most useful to determine WAT because of the transparent nature of model oils. With same apparatus, ASTM D97 is also applicable to determine the pour point of waxy oils in a serial determination. In case of emulsified model oils, however, it is difficult to measure WAT because of its opaque nature. This study employed FTIR spectroscopy to determine wax precipitation temperature and discussed the effect of emulsion state regarding the values of WAT. Further study would be needed to conclude the effect of water contents to WAT values in case of emulsified waxy oil.

• International Journal of Automotive Technology
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• v.4 no.2
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• pp.95-100
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• 2003

Automobile industry has been developed rapidly as a key manufacturing industry in Korea. Meanwhile, air pollution is getting worse noticeably than ever. In the diesel emission, PM (Particulate Matter) and NOx (Nitrogen Oxides) have been exhausted with a great amount and the corresponding emission regulations are getting stringent. In order to develop low emission engines, it is necessary to research on better qualified fuels. Sulfur contained in fuel is transformed to sulfur compound by DOC (Diesel Oxidation Catalyst) and then it causes to the increase of sulfate-laden PM on the surface of catalyst. In this research, ULSD (Ultra Low Sulfur Diesel) is used as a fuel and some experimental results are investigated. ULSD can reduce not only PM but also gas materials because cetane value, flash point, distillation 90%, pour point and viscosity are improved in the process of desulfurization. However, excessively reduced sulfur may cause to decease lubricity of fuel and engine performance in fuel injection system. Therefore, it requires only modest adjusted amount of sulfur can improve engine performance and DOC, as well as decrease of emission.

• Journal of the Korean Chemical Society
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• v.11 no.1
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• pp.17-21
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• 1967

For utilization of Bunker-C residual oil produced at KOCO., the auther tested the properties of vacuum fraction and blown asphalt, and as the result of it, (1) Vacuum fraction had so broad range of viscosity and high flash point that could be produced all kind of lublicating oil, but had to be dewaxed for high pour point, (2) Urea dewaxing was suitable to lighter fraction but not to heavier fraction, so, for heavier fraction, solvent dewaxing was needed. (3) Blown asphalt produced from vacuum residue had uniform relation between softening point and penetration in spite of broad change of blowing condition and adding of catalyst.

• Journal of Energy Engineering
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• v.24 no.2
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• pp.144-153
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• 2015

At low temperature, Wax build-up and settling can affect adversely the cold weather performance of the diesel vehicle. In this study, we test the cold properties of diesel by blending ratio of biodiesel, kerosene and WAFI. Also, we test the cold weather performance for diesel vehicle by fuel cold properties. Cold properties of diesel are improved by adding the WAFI, kerosene and get worse by adding the biodiesel. WAFI is effective to improve a cold filter plugging point(CFPP) and Kerosene is effective to improve a cloud point(CP). CFPP and pour point(PP) are related to cold weather performance of diesel vehicle but CP is unrelated. CFPP indicate a limit temperature of vehicle driving possibility.

• Tribology and Lubricants
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• v.36 no.6
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• pp.385-390
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• 2020

It rains heavily, such as long rain and typhoons, during a typical rainy season in Korea. In this season, several fuel contamination accidents by water and vehicular problems caused by water contaminated fuel occur. Many research groups have studied the effects of water contaminated fuel on vehicles and environment. However the characteristics of water contaminated fuel have not been studied. In this study, we prepared diesel samples with a constant ratio of water (0~30 volume %) using an emulsifier. Then, we analyzed these diesel samples for their representative fuel properties. In the analytical results, diesel with 30% water showed an increase in fuel properties such as density (823→883 kg/㎥), kinematic viscosity (2.601→6.345 ㎟/s), flash point (47→56℃), pour point (-22→2℃), CFPP (cold filter plugging point) (-17→20℃) and copper corrosion number (1a→2a). The low temperature characteristics, such as low pour point and CFPP, blocks the fuel filter in the cold season. In addition, water contaminated diesel decreases lubricity (190→410 ㎛) under high frequency reciprocating rig (HFRR) and derived cetane number (54.81→34.25). The low lubricity of fuel causes vehicle problem such as pump and injector damage owing to severe friction. In addition, the low cetane diesel fuel increases exhaust gases such as NOx and particulate matters (PM) owing to incomplete combustion. This study can be used to identify the problems caused by water contamination to vehicle and fuel facilities.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.254-261
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• 2014

The transformer is a static electrical device that transfers energy by inductive coupling. Then, heat is occurred at coils, inner transformer was filled with insulating oils for cooling and insulation. Although mineral oil as insulating oil has been widely used, it does not meet health and current environmental laws because it is not biodegradable. Therefore, in this study, the diglycerol ester was synthesized with diglycerol and fatty acids (oleic acid and caprylic acid) over various catalysts for insulating oil having biodegradability, high flash points and low pour points. The sulfated zirconia ($SO_4{^{2-}}/ZrO_2$) catalyst prepared at different calcination temperature shows the highest conversion of fatty acids at $600^{\circ}C$ due to crystallinity and high density of acid sites per surface area. When the molar ratio of oleic acid and caprylic acid is 1:3, the diglycerol ester shows superior insulation properties that are the flash point of $306^{\circ}C$ and pour point of $-50^{\circ}C$. The insulation properties of synthesized diglycerol ester shows the pour point of $-50^{\circ}C$ and the flash point of over $300^{\circ}C$. Therefore, diglycerol ester is superior to the vegetable oils in insulation properties.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.864-872
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• 2020

In accordance with the sulfur regulations of the International Maritime Organization (IMO), very low sulfur fuel oil (VLSFO) shows various production-dependent physico-chemical properties. This study aims to use as basic data for oil spill response according to study of physico-chemical characteristics of VLSFO and mixed fuel oil of VLSFO-HSFO. The mixed fuel oil was prepared by mixing 25, 50, 75 mass% of HSFO with VLSFO containing 0.46 and 0.36 mass% of sulfur. The physico-chemical properties such as the kinematic viscosity, pour point and distribution of Saturates, Aromatics, Resins, and Asphaltenes (SARA) were studied in the laboratory. As mixed of 75 mass% of HSFO with high the kinematic viscosity and low pour point in VLSFO, the kinematic viscosity of the mixed fuel oil increased to 350.2 %, and VLSFO with pour point of 23℃ and -11℃ lowered or raised to -3℃ and -6℃ respectively. As HSFO was mixed in VLSFO with a small Asphaltenes distribution, the Saturates distribution decreased to 68.8% and Asphaltenes distribution increased to 1,417 % dramatically.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1987.06a
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• pp.1-18
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• 1987

윤활유 첨가제는 윤활기유의 물리적, 화학적 성질을 보완 또는 강화시킴으로서 윤활유로서 소기의 목적을 달성케하도록 첨가하는 원유증유분이 아닌 화학물질로서 그 종류는 사용목적에 따라 많은 종류가 사용되고 있다. 현재는 년 300 ton 규모의 pilot-plant 에서 5종의 첨가제 시제품을 생산하여 이들의 additive package를 제조하고 VI improver, pour point depressant 등 기타 첨가제들과 혼련시켜 10W-30 SF/CD 급의 내연기관용 윤활유 제조를 위한 혼련기술을 개발중에 있다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10a
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• pp.55-62
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• 2002

Significant changes in the performance requirements of finished lubricants is having a pronounced impact on the quality and manufacturing approach for base stocks, the building block for these products. Separation processing is no longer capable of producing high yields of premium base stocks and is rapidly being replaced with hydroprocessing. Isoparaffins are the most desirable component because of their high Viscosity Index, low pour point and excellent stability. This paper will discuss industry trends and the drive towards higher quality base stocks. Manufacturing options are discussed and examples presented to demonstrate the performance of these premium base stocks.