• 한국안전학회지
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• 제25권6호
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• pp.81-85
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• 2010

In recent years, environmental concerns have been raised on the use of poorly biodegradable fluids in electrical apparatus in regions where spills from leaks and equipment failure could contaminate the surroundings. The vegetable insulation oils are highly biodegradable, have negligible effect on the environment, human health and ecosystem. Therefore, to assure their safe use in electrical power systems, it may require some processing and modification to improve some of their physical, chemical, thermal and electrical properties. This paper provides a comparative results of the electrical breakdown properties of several vegetable insulation oils and mineral oil to use as dielectric fluid in environmental-friendly pole transformer. Also, the electrical breakdown property of the Nomex and kraft insulation papers in vegetable insulation oil is examined.

• Tribology and Lubricants
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• 제34권4호
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• pp.160-167
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• 2018

Vegetable oils can contribute to the goal of energy independence and security owing to their naturally renewable resources. One of the representative vegetable oils is biodiesel, which is being used in domestic and European markets as a blended fuel with automotive diesel. Vegetable oils are promising candidates as base fluids to replace petroleum lubricants because of their excellent lubricity and biodegradability. We prepared biodiesel with a purity of 99.9% via the esterification of waste cooking oil. Blended biodiesel and Petro-lube base oil were mixed to produce five types of mixed lubricating oil. We analyzed the various characteristics of the blended biodiesel with Petro-lube base oil for different blending ratios. The lubricity of the vegetable lubricant improves as the content of biodiesel increases. In addition, since zinc dialkyldithiophosphates (ZnDTPs) are widely used as multifunctional additives in petroleum-based lubricants, we optimized the blending ratio for lubricity, oxidation stability, and shear stability by adding ZnDTP as a performance additive to improve the biodiesel properties, such as oxidation stability and hydrolysis. The optimized lubricants improve by approximately 25% in lubricity and by 20 times in oxidation stability and shear stability after the addition of ZnDTP.

• 신재생에너지
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• 제8권4호
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• pp.30-37
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• 2012

Biodiesel was produced by "transesterification" of vegetable oils and animal fats as an alternative to petroleum diesel. The research analysed the fuel characteristics of biodiesel, the yield of by-products and biodiesel, using several vegetable oils - rapeseed oil, camellia oil, peanut oil, sesame oil, perilla oil, palm oil, olive oil, soybean oil, sunflower oil and animal fats such as lard, tallow, and chicken fat. The results showed the yields of biodiesel made from the vegetable oils and animal fats were $90.8{\pm}1.4{\sim}96.4{\pm}0.9%$ and $84.9{\pm}1.1{\sim}89.6{\pm}1.5%$ respectively. Production rates and oxidation characteristics were different depending on the fats applied.

• 한국분무공학회지
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• 제14권2호
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• pp.49-58
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• 2009

Non-edible vegetable oils instead of edible vegetable oils as a substitute for diesel fuel are getting a renewed attention because of global reduction of green house gases and concerns for long-term food and energy security. Out of various non-edible vegetable oils, karanja, mahua, linseed, rubber seed and cotton seed oils are selected in this study. A brief review of recent works related to the application of the above five vegetable oils and its derivatives in CI engines is presented. The production technologies of biodiesel based on non-edible vegetable oils are introduced. Problems in vegetable oil or biodiesel fuelled CI engine are included. In addition, future works related to spray characteristics of non-edible vegetable oil or biodiesel from it are discussed. The biodiesel fuel, irrespective of the feedstock used, results in a decrease in the emission of hydrocardon (HC), carbon monoxide (CO), particulate matter (PM) and sulphur dioxide ($SO_2$). It is also said to be carbon neutral as it contributes no net carbon dioxide to the atmosphere. Only oxides of nitrogen (NOx) are reported to increase which is due to oxygen content in the biodiesel fuel. The systematic assessment of spray char-acteristics of neat vegetable oils and its blends, neat biodiesel and its blends f3r use as diesel engine fuels is required.

• Journal of Biosystems Engineering
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• 제23권2호
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• pp.125-134
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• 1998

It seems possible, by use of vegetable oils, to solve the pollution problem caused by the exhaust gas from diesel-engine vehicles. Recently vegetable oils has received considerable attention as an alternative and clean energy source to the foreseeable depletion of world oil supplies. The objective of this study is to experimentally investigate the characteristics of exhaust emissions of a small diesel engine using light oil, rice-bran oil, heated rice-bran oil, rice-bran oil treated with ultrasonic energy. SO$_2$ emission from the pure and the treated rice-bran oils was not detected at speeds hgher than 1,800 rpm while that from the light oil was detected at all the speeds at 4/4 load. NOx emission form these vegetable oils was generally higher compared to that from the light oil for most of the test conditions. tendency opposite to that of NOx emission. The data obtained in this experiment may be applicable for the desist of small diesel engine using the alternative fuels.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.453-456
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• 2004

This paper surveys the latest findings on vegetable-oil-based dielectric coolants in power systems. In recent years, environmental concerns have been increased on the use of poorly biodegradable mineral oils in distribution and power transformers in regions where spills from leaks and equipment failure could contaminate the surroundings. In addition, there are demands to improve equipment efficiencies in power systems. In this reason, researches were started in the mid 1990s to develop a fully biodegradable dielectric coolants. Vegetable oil was considered the most likely candidate for a fully biodegradable dielectric coolants. Vegetable-oil-based dielectric coolants provide the advantages of high level of biodegradability, renewable natural resource, non-toxic properties, enhanced fire safety, more effective cooling and good dielectric strength for many electrical equipment.

• 한국전기전자재료학회논문지
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• 제25권10호
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• pp.791-797
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• 2012

Mineral insulating oils are an important insulating materials in oil-filled transformer. However, the mineral oil is the cause of the environmental problem. The vegetable oils are substitutes for mineral oil because of its biodegradability characteristic. As large size and high rating of the transformer increases, the losses increase at a faster rate. So insulating oil is forced circulation in the oil-filled transformer by using oil pumps. The flow electrification occurs when insulating oil was forced to be circulated. To check the flow electrification, had conducted experiments varying factors. As a result, the streaming electrification could see the changes according to flow velocity, oil temperature and insulation materials.

• Journal of Biosystems Engineering
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• 제37권6호
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• pp.429-433
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• 2012

Purpose: While rapeseed oil, soy bean oil, palm oil and waste cooking oil are being used for biodiesel, the viscosity of them should be lowered for fuel. The most widely used method of decreasing the viscosity of vegetable oil is to convert the vegetable oil into fatty acid methyl ester but is too expensive. This experiment uses ultrasonic energy, instead of converting the vegetable oil into fatty acid methyl ester, to lower the viscosity of the waste cooking oil. Methods: For irradiation treatment, the sample in a beaker was irradiated with ultrasonic energy and the viscosity and temperature were measured with a viscometer. For heating treatment, the sample in a beaker was heated and the viscosity and temperature were measured with a viscometer. Kinematic viscosity was calculated by dividing absolute viscosity with density. Results: The kinematic viscosity of waste cooking oil and cooking oil are up to ten times as high as that of light oil at room temperature. However, the difference of two types of oil decreased by four times as the temperature increased over $83^{\circ}C$. When the viscosity by the treatment of ultrasonic energy irradiation was compared to one by the heating treatment to the waste cooking oil, the viscosity by the treatment of ultrasonic energy irradiation was lower by maximum of 22% and minimum of 12%, than one by the heating treatment. Conclusions: Ultrasonic energy irradiation lowered the viscosity more than the heating treatment did, and ultrasonic energy irradiation has an enormous effect on fuel reforming.

• 한국분무공학회지
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• 제14권4호
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• pp.153-162
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• 2009

The use of inedible vegetable oils as substitute for diesel fuel in compression ignition engine is of significance because of the great need for edible oil as food, and the reduction of biodiesel production cost etc. Jatropha curcas oil which is a leading candidate for the commercialization of inedible vegetable oils is selected in this study for reviewing the application in CI engine as an alternative fuel. The important properties of jatropha oil (JO) and JO biodiesel are summarized from the various sources in the literature. It is found that five different types of alternative fuel from JO such as neat JO, JO blends with diesel or other fuel, neat JO biodiesel, JO biodiesel blends with diesel or other fuel and degummed JO were extensively examined in the diesel engine. Two different application types of alternative fuels from JO such as preheating and dual fuelling were also tested, It should be pointed out that most of these applications are limited to single cylinder conditions. The systematic study for the selection of effective application method is required. It is clear that the blends of JOME and diesel can replace diesel fuel up to 10% by volume for running the existing common rail direct injection systems without any durability problems. The systematic assessment of spray characteristics of different types of JO and its derivatives for use as diesel engine fuel is also required.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1660-1669
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• 2014

Partial discharge (PD) detection plays a major role in the life time assessment of liquid insulation in power transformers. Many research works are being carried out to replace conventional mineral oil insulation in transformers by vegetable oils. It is necessary to understand the PD characteristics of vegetable oils before recommending them as an alternate for mineral oil. In this paper, the breakdown strength and PD characteristics of palm and corn oil were investigated in both unaged and thermally aged conditions. Laboratory experiments were performed as per IEC test procedures. PD signals were measured using wide band detection system. Phase resolved PD pattern of vegetable oils and mineral oil were compared. Effect of increase in voltage stress on the PD pattern of palm and corn oil were studied. Time and frequency domain analysis of PD pulses at needle-plane electrode configuration was carried out. Statistical analysis of PD pattern i.e. skewness and shape parameter variations with respect to applied thermal stress were also carried out. From the results, it is observed that palm and corn oils have better breakdown strength and PD characteristics even under long-term thermal stress and hence they can be used for power transformer applications.