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Physicochemical and electrical properties of Jatropha curcas methyl ester oil as a substitute for mineral oil
... 3%, 90% of oil acidity and 3 Abdelmalik et al. [22,37] discovered that PKOAE Batch No. 2 has good AC breakdown voltage, kinematic viscosity, and flash point among all of the batches produced in their study. Sitorus et al. [38,39] produced J. curcas methyl ester oil (JMEO) from J. curcas seed oil through alkaline-catalyzed esterification with methanol. The results showed that there is enhancement in the AC breakdown voltage and pour point of the JMEO whereas there is a slight reduction in the kinematic viscosity. ...
Even though natural insulating oils (NEI) oils are environmentally friendly, these oils have not gained widespread use in high-voltage oil-immersed power transformers because of their unfavorable properties such as low pour point, low oxidation stability, low resistance to lightning impulse, and high kinematic viscosity. Hence, much effort has been made to overcome the disadvantages of NEI oils, including the addition of additives, modification of the chemical structure of oils and altering the transformer design to ensure compatibility with the oils. This review article is focused on the methods used to improve the workability of NEI oils in power transformers, namely, (1) depression of the pour point, (2) chemical modifications, (3) changes in the transformer design, (4) addition of nanoparticles, (5) addition of lightning resistance additives, and (6) addition of antioxidants. The benefits and challenges of each method are also discussed. It is believed that this review article offers new insight to scientists and researchers in this field.
This chapter deals with the most important processes to produce the different insulating liquids. The largest part is dedicated to vegetable oils and other oils, which can be used as insulating liquid. The production of the various dielectric insulating liquids is very different and has in some cases a lot of steps to obtain high purity insulating liquids. All the considerations are made with reference to mineral oil which serves as the basis insulating oil most commonly used.
In this chapter, the origin of the various insulating liquids and their basic chemical structure, which are very different, are described. Also, additives that positively influence the properties for use as an insulating liquid are presented. The idea is to replace mineral oil, which is currently the most commonly insulation liquid, by other insulating liquids especially by biological liquids. In addition to technical and economic points, the focus is on the combustibility of the insulating liquids and ecological aspects. As reference for all these considerations and investigations, mineral oil serves as the current dominant insulating oil. The main area of the application of these oils is the use as insulating and cooling material in transformers. In general, a distinction between polar and non-polar insulating liquids can be made. Polar liquids have a constant dipole moment, which results in a displacement of positive and negative charge centers, even when no external influences (electrical field, temperature, pressure,…) are present. A typical characteristic of polar liquids is their higher (relative) permittivity.
For decades, petroleum-based mineral oils are the insulating media conventionally used in the industry, particularly for high voltage (HV) applications. However, due to the disadvantages of mineral oils, there is growing interest in replacing these oils with environmentally friendly alternatives in order to fulfill the demanding requirements of dielectric liquids. One of the promising substitutes for mineral oils is ester oils. Nevertheless, the implementation of ester oils is not widespread compared with mineral oils due to the lack of understanding on the performance of ester oils in HV applications. Hence, the objective of this study is to investigate the bridging phenomenon of two dielectric liquids with different viscosities: palm fatty acid ester and mineral oil under the influence of direct current electric field. The results show that oil viscosity plays an important role in the formation of cellulose bridge and breakdown behavior. Copyright © 2017 Institute of Advanced Engineering and Science. All rights reserved.
Oil impregnated insulation paper plays an important role in a transformer as it insulates the windings from high voltage and current. Other than the type of paper used, the properties of oil such as viscosity, relative permittivity and dielectric loss play a major factor that contributes to the quality of the insulation paper. This paper discussed the sonication and esterification process on palm oil and treated waste vegetable oil and its’ effects on the performance of oil impregnated paper. Basically through these processes, viscosity of oils will reduce. However, the resultant permittivity and dielectric loss as well as its’ breakdown strength are rarely reported. Experiments were set to process (sonicates and esterify) the natural oils prior to the paper impregnation process. Results show that esterification is more effective than sonication process in reducing insulation oil viscosity, relative permittivity and dissipation factors as well as increasing the breakdown voltage of the oil impregnated paper. Palm oil methyl ester (POME) could serve as an excellent insulation oil which is very suitable as transformer oil as well as the impregnation medium for paper insulation.
The emergence of the concept of sustainable manufacturing practices and, therefore, the requirement to adapt ISO-14000 standards, it is essential to evaluate all manufacturing practices using sustainability criteria. Use of vegetable oil-based fluids for industrial applications has a higher sustainability index compared to hydrocarbon and synthetic based fluids. In this paper, the authors have investigated the technical feasibility of newly proposed Jatropha curcas oil based bio dielectric (Jatropha BD) fluid for electric discharge machining (EDM) with a view to improving the sustainability of EDM process. Experimental analysis has been performed for material removal rate (MRR), surface roughness (SR) and surface hardness (SH) under the influence of current, gap voltage, pulse on time and pulse off time. analysis of variance (ANOVA) has been performed to identify the significance of the control parameters on the response characteristics. The results obtained indicate that Jatropha BD resulted in higher MRR, lower SR and improved SH than kerosene. Moreover, the response patterns of Jatropha BD are similar to kerosene which is an indication that material melting and evaporation mechanics are as like kerosene. Regression models have been generated to model the response behavior of the parameters. Regression models predicted the response of the parameters in good conformance. It is suggested that Jatropha oil based bio dielectric fluids can be used as an alternative to hydrocarbon based dielectric for improving sustainability of EDM process.
Due to their high biodegradability, non-toxicity and higher fire safety guarantee, vegetable-based oils are considered today as a potential substitute for mineral and synthetic liquids for electrical insulation and especially in high voltage power transformers. However most of known vegetable oils are derived from food materials (rape-seeds, sunflower, palm, olive). And one has to be vigilant to the fact that the replacement of mineral oil which is a petroleum-based product by natural ester fluids based on “renewably sourced” vegetable oils, does not create new problems as this could cause global food crisis due to diversion of food. An interesting product can be jatropha curcas oil extracted from jatropha curcas plants (“miracle tree”) which is non-food crops. This paper presents an experimental study of creeping discharges propagating over pressboard of different thicknesses immersed in jatropha curcas methyl ester oil (JMEO) and mineral oil (MO) under positive and negative lightning impulse voltages (1.2/50 μs), using two divergent electrode configurations (electrode point perpendicular and tangential to pressboard). It is shown that the thickness of pressboard significantly influences the characteristics of creeping discharge and especially the stopping (final) length Lf and the density of branches. For a given thickness, Lf increases with the voltage and decreases when the thickness increases. Lf is longer when the point is positive than with a negative point. For a given voltage and thickness of pressboard, the values of Lf in mineral oil and JMEO are very close.
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