Setijo Bismo

Physicochemical and electrical properties of jatropha curcas methyl ester oil as a substitute for mineral oil

This paper reports the investigation of jatropha curcas seeds oil as an alternative option to replace mineral oil in power transformers. This product has several advantages that recommend both its production and usage over that of other vegetable oils as crude palm oil and rape-seeds oil because it may be grown on marginal or degraded soils thus avoiding the need to utilize those more fertile soils currently being used by smallholders to grow their staple crops; and it will readily grow in areas where annual rainfall levels are significantly lower than those required by other species such as oil palm, rape-seeds oil, sunflower oil, soybeans oil, corn oil and others. For instance, these plants can be grown on all soil types in Indonesia, even on barren soil. The barren soil types can be found in many parts of eastern Indonesia that remain untapped because of the difficulty planted with other crops. Moreover, jatropha curcas oil is non-food crops. Jatropha curcas oil is processed by alkali base catalyzed esterification process using potassium hydroxide (KOH) to produce jatropha curcas methyl ester oil (JMEO) that is a product the viscosity and acidity are acceptable for high voltage equipment especially in power transformer. The physicochemical (water content, viscosity, acidity ...) and electrical (dielectric strength) properties of JMEO were measured. For comparison, we also measured breakdown voltage of mineral oil (MO) in the same experimental conditions. The obtained results show that the average AC breakdown voltages of JMEO and MO are too close.

Pre-breakdown phenomena in new vegetable oil - based jatropha curcas seeds as substitute of mineral oil in high voltage equipment

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, soybeans, palms, corns and others). And one has to be vigilant to the fact that the replacement of mineral oil 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 into insulating material oils or others (fuel). An interesting product can be jatropha curcas oil (JCO) extracted from the fruit seeds of jatropha curcas plants (“miracle tree”) which is non-food crops. These plants can be grown on marginal or degraded soils and thus enables to avoid the need to utilize those more fertile soils currently being used by smallholders to grow their staple crops; and they readily grow in areas where annual rainfall levels are significantly lower than those required by other species such as rape-seeds, sunflower, palm, soybeans, corns and others. This paper presents an experimental study of streamers phenomena in jatropha curcas methyl ester oil (JMEO) and mineral oil (MO) under positive and negative lightning impulse voltages (1.2/50 μs); JMEO is obtained by alkali base catalyzed trans-esterification process of JCO to reduce the viscosity and acidity. It is shown that basing on the streamer characteristics (shape, stopping length, velocity, current and electrical charge), JMEO could constitute a potential substitute for mineral for electrical insulation and especially in high voltage power transformers.

Comparison of streamers characteristics in jatropha curcas methyl ester oil and mineral oil under lightning impulse voltage

Due to their high biodegradability, non-toxicity and 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, soybeans, palms, corns and others). And one has to be vigilant to the fact that the replacement of mineral oil 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 into insulating material oils or others (fuel). An interesting product can be jatropha curcas oil extracted from the fruits of jatropha curcas plants (“miracle tree”) which is non-food crops. These plants can be grown on marginal or degraded soils (thus avoiding the need to utilize those more fertile soils currently being used by smallholders to grow their staple crops); and it will readily grow in areas where annual rainfall levels are significantly lower than those required by other species such as rape-seeds, sunflower, palm, soybeans, corns and others. This paper presents an experimental study of streamers phenomena in jatropha curcas methyl ester oil (JMEO) and mineral oil (MO) under positive and negative lightning impulse voltages (1.2/50 μs). It is shown that basing on the shape and stopping length of streamers, JMEO could constitute a potential substitute for mineral and synthetic oils for electrical insulation and especially in high voltage power transformers.

Jatropha curcas methyl ester oil obtaining as vegetable insulating oil

This paper presents a new vegetable oil that is jatropha curcas seeds oil as a substitute for mineral oil. This product has several advantages among which the fact that it is non-food crops and may be grown on low fertile soils and areas where annual rainfall levels are significantly lower than those required by other plants used to extract other vegetable oils such as rape-seeds, sunflower, corn, soybeans, grape-seeds and sesame. The considered natural ester oil is processed by alkali base catalyzed esterification process using potassium hydroxide (KOH) to produce jatropha curcas methyl ester oil (JMEO). The physicochemical (water content, relative density, viscosity, acidity, visual examination, color, iodine number, corrosivity, flash point, pour point) and electrical (breakdown voltage under ac, dc and impulse voltages) properties of JMEO are presented and discussed. A gas chromatography (GC) analysis is also achieved to identify the methyl ester components in JMEO. The breakdown voltage of JMEO is compared to that of mineral oil (MO). It is found that the average breakdown voltage of JMEO and MO under different voltage waveforms are too close.

Creeping discharges over pressboard immersed in jatropha curcas methyl ester and mineral oils

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.

Disinfection of Escherichia coli bacteria using hybrid method of ozonation and hydrodynamic cavitation with orifice plate

This research aims to evaluate the performance of hybrid method of ozonation and hydrodynamic cavitation with orifice plate on E.coli bacteria disinfection. In this research, ozone dose, circulation flowrate, and disinfection method were varied. Ozone was produced by commercial ozonator with ozone dose of 64.83 mg/hour, 108.18 mg/hour, and 135.04 mg/hour. Meanwhile, hydrodynamic cavitation was generated by an orifice plate. The disinfection method compared in this research were: hydrodynamic cavitation, ozonation, and the combination of both. The best result on each method was achieved on the 60th minutes and with a circulation flowrate of 7 L/min. The hybrid method attained final concentration of 0 CFU/mL from the initial concentration of 2.10 × 105 CFU/mL. The ozonation method attained final concentration of 0 CFU/mL from the initial concentration of 1.32 × 105 CFU/mL. Cavitation method gives the least disinfection with final concentration of 5.20 × 104 CFU/mL from the initial concentration of 2.17 × 10...

Comparison of statistical breakdown voltages in jatropha curcas methyl ester oil and mineral oil under AC voltage

Due to their dielectric strength, viscosity and oxidation stability, mineral oils have been used for more than one hundred years ago as insulation liquid in high voltage equipment. However, mineral oils are non-renewable materials and have a low level biodegradability; their level of biodegradability is not more than 30 %. For that purpose, the development of vegetable oils is being continuously performed by many researchers and industries to replace mineral oils. These natural products present a high biodegradability, non-toxicity and higher fire safety guarantee. In general, vegetable oils which have been used today are derived from food material such as soybeans, palm, corn, sunflower and others. In this paper, we first introduce a new vegetable oil derived from a non-food material we called “JMEO (jatropha curcas methyl ester oil)”. JMEO is produced by alkaline esterification process of jatropha curcas oil which comes from the pressing of jatropha fruits. Jatropha curcas are non-edible crop that can grow in all types of soil in tropical and subtropical regions and even in barren soils with low rainfall. Moreover, these plants do not need much fertilizer. Then we present the results of a comparison of statistical AC breakdown voltage in JMEO and mineral oil (naphtenic type). Breakdown voltage (BDV) measurements have been performed on series of 40 tests basing on IEC 60156 Standard. Hypothesis test of conformity to normal distribution of BDV is carried out by applying Shapiro-Wilk tests to calculate W-value and P-value and skewness and kurtosis test. We mainly analyze histogram, probability of oil samples, mean and standard deviation. It appears from the obtained results that the BDV of JMEO is better than that of mineral oil. Thus, JMEO (jatropha curcas methyl ester oil) constitutes a potential liquid for replacing mineral oil in high voltage equipment and especially in high voltage power transformer.

Significance of Acoustic and Hydrodynamic Cavitations in Enhancing Ozone Mass Transfer

Assessment of both acoustic and hydrodynamic cavitations for intensifying ozone mass transfer was conducted simultaneously. Four process schemes were arranged to evaluate the effect of application of each kind of cavitation as well as both of them, on the ozone mass transfer process. All processes were conducted at pH of 3 to avoid ozone natural self-decomposition initiated by hydroxide ions (OH−). The chemical and mechanical effects of cavitation were distinguished by using radical scavengers to suppress radical formation. The result showed that hydrodynamic and acoustic cavitations enhanced ozone mass transfer synergistically. The enhancement obtained from the acoustic cavitation was higher than that obtained from the hydrodynamic cavitation, and the chemical effects of cavitation were much significant than that of mechanical effects. The enhancement obtained due to chemical effects of cavitation was about twice the enhancement obtained due to mechanical effects when only one type of cavitation was combined with ozonation. Combination of both type of cavitation and ozonation gave the enhancement obtained due to chemical effect of 3.68 times that obtained due to mechanical effects.

Effect of Process Condition in Plasma Electrolysis of Chloralkali Production

Chlor-alkali is one of the most important processes in chemical industry. This process produces chlorine and caustic soda that becomes the main feedstock of daily needs products. In this study, the process condition on chlorine gas production by electrolysis plasma is examined. Plasma electrolysis can increase the chlorine gas production up to 24 times in single compartment reactor and can reach up to 59 times in double compartment reactor compared to electrolysis process. In reactor with single compartment, high voltage results high current then cause high-energy consumption. The highest chlorine gas production is at 0.5 M and 300 V that results 4.63 mmol within 15 minutes. On the other hand, using double compartment reactor, current is lower due to its higher distance between two electrodes that makes the higher resistance. In this case, the highest chlorine gas production is at 0.5 M NaCl and 700 V that results 11.25 mmol within 15 minutes. The use of ion selective membrane can keep the movement of charge from one electrode to other. Ion selective membrane can separate side product of NaOH, but side reaction of chlorine ion still exists. NaCl, will be decomposed in the solvent and form ions in the solution. Positive discharge electrode is called anode and the negative one is cathode. Each electrode bonds ions which have different discharge, so that ions with negative discharge will go to anode and the positive ions will go to cathode. Nevertheless, electrolysis of NaCl solution (brine electrolysis) used in chlor-alkali production has significant weaknesses, those are low conversion resulted by the electrolysis process and the use of high electric current when the electrolysis process occur (4). Hence, it is needed to observe other possible technologies that can be applied in the production of chlor-alkali to reduce the energy consumption. One of the technologies that can reduce the energy consumption is plasma electrolysis. The plasma electrolysis process is similar with electrolysis process, but it is done with high enough voltage until the electric spark is formed producing the plasma on the electrolyte solution. The plasma will produce reactive species such as radicals on large amount which are accelerated by the sharp potential gradient and have enough kinetic energy to induce unique chemical changes in aqueous solutions, so it is able to increase the formation of products in solution several more times than the Faraday electrolysis process (5), (6). Using this technology may reduce the energy consumption several times than conventional electrolysis so the productivity is more effective (6).

Statistical analysis of AC and DC breakdown voltage of JMEO (Jatropha methyl ester oil), mineral oil and their mixtures

This paper reports on a comparative study of statistical Breakdown Voltage (BDV) in a natural ester oil namely jatropha curcas methyl ester oil (JMEO) extracted from the fruit seeds of jatropha curcas plants, mineral oil (MO) and two JMEO/MO oil mixtures (namely (50%JMEO+50%MO) and (80%JMEO+20%MO)) using spherical electrode under DC and AC voltages. It is shown that the average AC breakdown voltage of JMEO is higher than that of mineral oil. Meanwhile it is similar under DC voltage. The statistical analysis shows that all large data groups (n>40) for AC and DC breakdown voltages of JMEO, MO and oil mixtures obey to the normal distribution law. This is proved using Shapiro-Wilk test, skewness and kurtosis values. It also observed that AC mean breakdown voltage of JMEO is higher than that of oils mixture (50%JMEO+50%MO) and MO, but it is similar with oils mixture (80%JMEO+20%MO). AC mean breakdown voltage of MO is the lowest one. DC mean breakdown voltages of JMEO, MO and oil mixtures (50%JMEO+50%MO) are similar. In contrast, DC mean breakdown voltage of oils mixture (80%JMEO+20%MO) is the highest one.