• Analytical Science and Technology
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• v.27 no.1
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• pp.41-59
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• 2014

The aims of this work were the identification and the classification of fresh lubricants and used engine oils of vehicles for the application in forensic science field-80 kinds of fresh lubricants were purchased and 86 kinds of used engine oils were sampled from 24 kinds of diesel and gasoline vehicles with different driving conditions. The sample of lubricants and used engine oils were analyzed by GC/MS. The Bayesian model technique was developed for classification or identification. Both the wavelet fitting and the principal component analysis (PCA) techniques as a data dimension reduction were applied. In fresh lubricants classification, the rates of matching by Bayesian model technique with wavelet fitting and PCA were 97.5% and 96.7%, respectively. The Bayesian model technique with wavelet fitting was better to classify lubricants than it with PCA based on dimension reduction. And we selected the Bayesian model technique with wavelet fitting for classification of lubricants. The other experiment was the analysis of used engine oils which were collected from vehicles with the several mileage up to 5,000 km after replacing engine oil. The eighty six kinds of used engine oil sample with the mileage were collected. In vehicle classification (total 24 classes), the rate of matching by Bayesian model with wavelet fitting was 86.4%. However, in the vehicle's fuel type classification (whether it is gasoline vehicle or diesel vehicle, only total 2 classes), the rate of matching was 99.6%. In the used engine oil brands classification (total 6 classes), the rate of matching was 97.3%.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.274-278
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• 2013

Automatic transmission fluid (ATF) is used as an automatic transmission in the vehicle or as a characterized fluid for automatic transmission. Recently, vehicle manufacturers usually guarantee for changing fluids over 80000~100000 km mileage or no exchange. However, most drivers usually change ATF below every 50000 km driving distance when driving in Republic of Korea according to a survey from the Korea Institute of Petroleum Management which can cause both a serious environmental contamination by the used ATF and an increase in the cost of driving. In this study, various physical properties such as flash point, pour point, kinematic viscosity, dynamic viscosity at low temperature, total acid number and four-ball test were investigated for both fresh ATF and used ATF after the actual vehicle driving distance of 50000 km and 100000 km. It was shown that most physical properties were suitable for the specification of ATF, but the foam characteristics of the used oil after running 100000 km was unsuitable for the specification of fresh ATF. Therefore, the exchange cycle of ATF every 80000~100000 km driving distance is recommended considering great positive contributions to preventing environmental pollution and reducing driving cost.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.289-297
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• 2018

The vehicle lubricant has captured 35% of the total lubricant market while the engine oil possessed 77% of the vehicle lubricant market in Korea. The suitable quality management of circulating engine oil is thus required for the driver and engine protection. But, KS and synthetic engine oil products (containing over 30% synthetic oil) are exempt to any quality inspections under Petroleum and Alternative Fuel Business Act. In this study, our research group investigated the quality monitoring of 30 kinds of domestic distributing synthetic engine oils. Two kinds of the engine oil showed an off specification from the test results; one engine oil is an imported and the other is a KS synthetic one. Also, the pattern of engine oils were analyzed using SIMDIST (simulated distillation) and the most engine oils had a broad carbon number spectrum, which is a typical of mineral oils except several imported products. Thus, we concluded that relevant laws for the proper quality management of synthetic oils and KS products are needed to be established for preventing consumer's damages.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.632-637
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• 2017

The vehicle lubricant occupies upto 35% in a total lubricant market and engine oil occupies upto 77% in the vehicle lubricant market in Korea. A suitable quality management of the circulating engine oil is necessary for driver and engine protection. But, KS and synthetic engine oil products (involved over 30% synthetic oil) are exempt to any quality management under Petroleum and Alternative Fuel Business Act. It is also known that synthetic oils such as PAO (poly alpha olefin) have excellent properties and performance like anti-wear, varnish control and oxidation stability than those of mineral oils. For this reason, PAO has been used for an engine oil, rotary screw and reciprocating compressor in addition to heavy duty and other extreme service applications. In this study, our research group analyzed the chromatogram pattern for the mineral oil, PAO and mineral oil involved a typical ratio of PAO using SIMDIST (simulated distillation). In the SIMDIST chromatogram, the mineral oil showed a broad peak, while PAO showed a sharp typical peak. Also the oil with a large viscosity grade exhibited a long retention time due to the heavy molecular weight and high boiling point. In particular, the blended mineral oil with 20% PAO sample showed a distinctly different pattern compared to that of using the conventional mineral oil. For monitoring PAO contents in distributing engine oils, we analyzed the SIMDIST for 27 kinds of engine oils which were popularly sold in Korea. The analytic results indicate that all kinds of engine oils showed that PAO contents were below 20% in engine oil products. Moreover, the PAO titled product was found to have a small amount of PAO. Thus, we conclude that the related laws for the proper quality management of synthetic oils are needed to be established.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.176.2-176.2
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• 2011

피마자유(Castor oil)는 합성수지, 그리스, 유압용 오일, 윤활기유 등의 다양한 용도로 쓰이는 오일로서 점도가 높고 무색에서 황갈색을 띈다. 피마자유 추출은 압착 착유 또는 용매 추출로 얻게 되며 본 실험에 사용된 오일은 압착 착유한 것으로 매우 진한 갈색을 띄는 정제전 오일을 이용하였다. 실험에 사용된 피마자유의 초기 산가는 1mgKOH/g 이하로 낮은 유리지방산 함량을 보였으며 수분은 0.3%로 전이에스테르화 반응을 위해서는 수분 증발이 필요했다. 피마자유의 바이오디젤 생산을 위해 진행된 물성 분석 항목은 산가, 수분, 인함량, 황함량, 점도, 고형물이며 원료유와 그 바이오디젤에 대해 각각 물성 분석을 실시하였다. 피마자유의 가장 큰 특징은 다른 식물성 오일과는 다르게 오일이 알코올에 녹는 특성이 있으며 이런 이유로 전이에스테르화 반응 후 바이오디젤과 글리세롤이 분리되지 않는 문제점을 갖고 있다. 피마자유를 이용해 제조한 바이오디젤, 즉 지방산메틸에스터의 함량을 분석한 결과 약 90%의 메틸에스터화 반응 전환율을 나타내었으나 국내외 품질규격상의 탄소수 C14~C24:0의 지방산 에스터(fatty acid methyl esters)로 검출되는 바이오디젤의 함량은 10% 미만으로 나타났으며 나머지 90%는 라이신올레익산메틸에스터(ricinoleic acid methyl ester)로 분석되었다. 따라서, 기존의 대두유, 유채유, 팜유, 폐식용유로부터 제조한 바이오디젤과 물성이 매우 상이하고 특히 끊는점(boiling point)과 점도가 높아 경유 대체연료로는 활용이 불가능할 것으로 판단된다. 하지만 기존의 다양한 용도의 오일로 사용하기 위해 정제하는 과정에서 전체 착유 오일중의 약 10%만을 선택적으로 분리하여 바이오디젤 원료로 활용하는 방안은 가능할 것으로 판단된다.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.533-540
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• 2018

Graphene has been reported to be an excellent lubricant additive that reduces friction and wear when coated on the surface of various materials or when dispersed in lubricants as an atomic thin material with the low surface energy. In this study, alkyl functionalized graphene oxide (FGO) nanosheets for oil-based lubricant additives were prepared by using three types of alkyl chloride chemicals (butyl chloride, octyl chloride, and tetradecyl chloride). The chemical and structural properties of the synthesized FGOs were analyzed by Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), and transmission electron microscope (TEM). The synthesized FGOs were dispersed at 0.02 wt% in PAO-0W40 oil and its tribological characteristics were investigated using a high frequency friction/wear tester. The friction coefficient and the wear track width of poly alpha olefin (PAO) oil added with FGO-14 were tested by a ball-on-disk method, and the measured results were reduced by ~5.88 and ~3.8%, respectively compared with those of the conventional PAO oil. Thus, it was found that the wear resistance of PAO oil was improved. In this study, we demonstrated the successful functionalization of GO as well as the improvement of dispersion stability and tribological characteristics of FGOs based on various alkyl chain lengths.

• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.51-58
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• 2008

A series of oleic acid esters containing mercaptobenzothiazole and dialkylenedithiocarbamate, which are potential environmentally friendly lubricating grease additives, were synthesized as 90% yield through several method such as nucleophilic substitution of dialkyl amine and carbon disulfide, reduction reaction, and condensation reaction. The structures of the additives were confirmed by $^1H$-NMR, FT-IR and EA analysis. The additives (1 wt%) were soluble in 100 N BO except C4-DTC-OE and soluble in soybean oil. The tribological properties as lubricating additives in 100 N BO were evaluated using 4-ball tester and the results showed as follows: Bz-thia-OE < C4-DTC-OE < Pyrro-DTC-OE < C8-DTC-OE. Whereas, the 4-ball anti-wear properties were not shown in soybean oil.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.9
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• pp.947-954
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• 2011

Drive-train friction loss in a vehicle may account for 4% of its total fuel consumption loss. An ATF W/C (auto-transmission fluid warmer/cooler) plate-fin heat exchanger is a type of heat exchanger that uses metal plates to transfer heat between the auto-transmission fluid and coolant. The use of an ATF W/C heat exchanger can result in a fuel economy improvement of about 1% in vehicles. An experimental setup for testing the thermal performance of an ATF W/C plate-fin heat exchanger is developed. In this study, the influence of the ATF and coolant, flow rates, and temperature on the efficiency of an ATF W/C heat exchanger are investigated experimentally. From the experimental data, a simple correlation for predicting the efficiency of an ATF W/C heat exchanger is proposed. On the basis of this correlation, the fuel economy of a vehicle with and without an ATF W/C heat exchanger is compared by using Simulink. Finally, it is shown that the fuel economy is improved by 0.992% when an ATF W/C heat exchanger is installed in the vehicle.

• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.521-526
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• 2016

Some thiadiazole and dithiocarbamate derivatives were desinged and synthesized in order to study the potential use as anti- wear additives. Their anti-wear properties in three different base oils (DB-51, soybean, and 100 N) were evaluated using a four-ball wear tester (ASTM D4172). The solubilities of dithiocarbamate derivatives in the base oils were better than those of thiadiazole derivatives. The compounds containing oleoyl group rather than nonanoyl group gave good anti-wear properties. The solubilities and anti-wear properties were explained by the polarity of the compounds.

• The Korean Journal of Petroleum Geology
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• v.14 no.1
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• pp.45-52
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• 2008

The GTL(Gas to Liquids) technology, manufacturing synthesized oil from natural gas, had been developed about 1920 for the military purpose by Fischer and Tropsch, German scientists. And 1960, Sasol company had started commercializing the FT(Fischer-Tropsch) synthesis technology, for the transport fuel in South Africa. Until a recent date, the commercialization of GTL technology had been delayed by low oil price. But concern about depletion of petroleum resources, and development in synthesizing technology lead to spotlight on the GTL businesses. Especially, Qatar, which has rich natural gas fields, aims at utilizing natural gas like conventional oil resources. Therefore, around this nation, GTL plants construction has been promoted. There are mainly 3 processes to make GTL products(Diesel, Naphtha, lube oil, etc) from natural gas. The first is synthesis gas generation unit reforming hydrogen and carbomonoxide from natural gas. The second is FT synthesis unit converting synthesized gas to polymeric chain-hydrocarbon. The third is product upgrading unit making oil products from the FT synthesized oil. There are quite a little sulfur, nitrogen, and aromatic compounds in GTL products. GTL product has environmental premium in discharging less harmful particles than refinery oil products from crude to the human body. In short, the GTL is a clean technology, easier transportation mean, and has higher stability comparing to LNG works.