• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.787-796
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• 1996

The biodegradation experiment, the TOD analysis and the element analysis for dispersant, Bunker-A oil and Bunker-B oil were conducted to study the biodegradation characteristics of a mixture of Bunker-A oil with dispersant and a mixture of Bunker-B oil with dispersant in the seawater. The results of biodegradation experiment showed 1mg of dispersant to be equivalent to 0.26 mg of $BOD_5$ and to 0.60 mg of $BOD_{20}$ in the natural seawater. The results of TOD analysis showed each 1 mg of dispersant, Bunker-A oil and Bunker-B oil to be equivalent to 2.37 mg, 2.94 mg and 2.74 mg of TOD, respectively. The results of element analysis showed carbon, hydrogen, nitrogen and phosphorus contents of dispersant to be $82.1\%,\;13.8\%,\;1.8\%\;and\;2.2\%$, respectively. Carbon and hydrogen contents of Bunker-A oil were found to be $73.3\%\;and\;13.5\%$, respectively, and carbon, hydrogen and nitrogen contents of Bunker-B oil to be $80.4\%,\;12.3\%\;and\;0.7\%$, respectively. Accordingly, the detection of nitrogen and phosphorus in dispersant shows that dispersants should be used with caution in coastal waters, with relation to eutrophication. The biodegradability of dispersant expressed as the ratio of $BOD_5/TOD$ was found to be $11.0\%$. As the mix ratios of dispersant to Bunker-A oil (3 mg/l) and a mixture of Bunker-B oil (3mg/l) were changed from 1 : 10 to 5 : 10, the biodegradabilities of a mixture of Bunker-A oil with dispersant and Bunker-B oil with dispersant increased from $2.1\%\;to\;7.2\%$ and from $1.0\%\;to\;4.4\%$, respectively. Accordingly, the dispersant belongs to the organic matter group of middle-biodegradability while mixtures in the mix ratio range of $1:10\~5:10$ belong to the organic matter group of low-biodegradability. The deoxygenation rate constant $(K_1)$ and ultimate biochemical oxygen demand $(L_0)$ obtained from the biodegradation experiment and Thomas slope method were found to be 0.125/day and 2.487 mg/l for dispersant (4 mg/l), respectively. $K_1\;and\;L_0$, were found to be $0.079\~0.131/day$ and $0.318\~2.052\;mg/l$ for a mixture of Bunker-A oil with dispersant and to be $0.106\~0.371/day$ and $0.262\~1.106\;mg/l$ for a mixture of Bunker-B oil with dispersant, respectively, having $1:10\~5:10$ mix ratios of dispersant to Bunker-A oil and Bunker-B oil. The ultimate biochemical oxygen demands of the mixtures increased as the mix ratio of dispersant to Bunker-A, B oils changed from 1 : 10 to 5 : 10. This suggests that the more dispersants are applied to the sea for the cleanup of Bunker-A oil or Bunker-B oil, the more decreases the dissolved oxygen level in the seawater.

• Tribology and Lubricants
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• v.34 no.5
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• pp.191-196
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• 2018

Bunker C is used in heavy-lift ships, furnaces, and boilers for generating heat, and power. Bunker C has only four regulations for quality standards and is rarely inspected in Korea. For these reasons, other oils such as used lubricant oil are commonly blended with Bunker C. This illegal mixture of fuel can damage the boilers, engines and affect the environment adversely. In this study, we investigate the fuel properties and perform atomic analysis of illegal Bunker C blended with used lube oil. The test results show that higher quantities of used lube oil in Bunker C have higher flash points, total acid numbers, copper corruption, solid contamination, and metal components. Further, increasing quantities of used lube oil in Bunker C cause lower viscosity, sulfur, and V content. However, adequate sample (approximately 1 L) is needed to evaluate presence of adulterants in Bunker C, we attempted the SIMDIST analysis. In the SIMDIST chromatogram, the used engine oils are detected for longer retention times than Bunker C owing to the high boiling point. We also quantitatively analyzed the lube oil content using SIMDIST.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.4
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• pp.227-230
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• 2000

Bunker-A oil-degrading microorganisms were isolated from a marine environment using an enrichment culture technique. The isolated strain EL-081K was identified as the genus Acinetobacter based on the results of morphological, culture, and biochemical tests. The optimal temperature and initial pH for bunker-A oil degradation were $25^{\circ}C$ and 7.0, respectively, including aeration. The optimal medium composition for the degradation of bunker-A oil by Acinetobacter sp. EL_O81K was 10 ml/l bunker-A oil as the carbon source and 0.1% (NH$_4$)$_2$SO$_4$as the nitrogen source. Under the above conditions, the biodegradability of bunker-A oil was 38% after 96 hours of incubation. The addition of detergent did not increase the bunker-A oil degradation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.519-528
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• 1993

The biodegradation experiment, the TOD analysis and the element analysis for dispersant, Bunker-C and dispersant/Bunker-C oil mixtures were conducted for the purposes of evaluating the biodegradability of dispersnat/Bunker-C oil mixtures and studying the consumption of dissolved oxygen with relation to biodegradation in the seawater. The results of biodegradation experiment showed the mixtures with $1:10{\sim}5:10$ mix ratios of dispersant to 4mg/l of Bunker-C oil to be $0.34{\sim}2.06mg/l$ of $BOD_5$ and to be $1.05{\sim}5.47mg/l$ of $BOD_{20}$ in natural seawater. The results of TOD analysis showed 1mg of Bunker-C oil to be 3.16mg of TOD. The results of element analysis showed the contents of carbon and hydrogen to be $87.3\%\;and\;11.5\%$ for Bunker-C oil, respectively, but nitrogen element was not detected in Bunker-C oil. The biodegradability of dispersant/Bunker-C oil mixture shown as the ratio of $BOD_5$/TOD was increased from $3\%\;to\;11\%$ as a mix ratio of dispersant to 4mg/l of Bunker-C oil changed from 1:10 to 5:10, and the mixtures were found to belong in the organic matter group of low-biodegradability. The deoxygenation rates($K_1$) and ultimate oxygen demands($L_o$) obtained through the biodegration experiment and Thomas slope method were found to be $0.072{\sim}0.097/day$ and $1.113{\sim}6.746mg/l$ for the mixtures with $1:10{\sim}5:10$ mix ratios of dispersant to 4mg/l of Bunker-C oil, respectively. The ultimate oxygen demand of mixture was increased as a mix ratio of dispersant to Bunker-C oil changed from 1:10 to 10:5. This means that the more dispersants are applied to the sea for Bunker-C oil cleanup, the more decreases the dissolved oxygen level in the seawater.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.04a
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• pp.88-96
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• 1996

The characteristic analysis of fly ash generated from a fired power plant using bunker-C oil has been investigated. Ash size distribution by an optical microscopy with image processing technique, morphological shape by a scanning electron microscope(SEM) and microscope, chemical composition by the inductively coupled plasma emission spectrometry(ICP), and resistivity measurement as a function of temperature and moisture content by the resistivity meter are performed. A study of physical, chemical and electrical characteristics of bunker-C fly ash plays an important role of improving the performance of an electrostatic precipitator and protecting air pollution. The samples of bunker-C fly ash for analysis were collected from the electrostatic precipitator hopper of Ulsan Power Plant Unit 1 and Pusan Power Plant Unit 1. Mass median diameter(MMD) of bunker-C fly ash was measured 12.7${\mu}{\textrm}{m}$, while MMD of fly ash generated from the mixture of bunker-C oil(40%) and domestic anthracitic coal(60%) was 25.7${\mu}{\textrm}{m}$. The morphological structure of bunker-C fly ash consisted of fine particles of non-spherical shape. The primary chemical components of bunker-C fly ash were composed of SiO2(2.36%), Al2O3(4.91%), Fe2O3(14.33%) and C(11.84%). Resistivity of bunker-C fly ash was found to be increased with increasing temperature at the range of 100~15$0^{\circ}C$ and was measured 103~104 ohm-cm.

• Korea Trade Review
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• v.44 no.1
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• pp.75-86
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• 2019

This study performs a factor analysis that affects the bunker oil price using the Co-integration model and Vector Error Correction Model (VECM). For this purpose, we use data from Clarkson and the analysis results show 17.6% decrease in bunker oil price when the amount of crude oil production increases at 1.0%, 10.3% increase in bunker oil price when the seaborne trade volume increases at 1.0%, 1.0% decrease in bunker oil price when total volume of vessels increases at 1.0%, and 0.003% increase in bunker oil price when 1.0% increase in world GDP, respectively. This study is meaningful in that this study estimates the speed of convergence to long-term equilibrium and identifies the price adjust mechanism which naturally exists in bunker oil market. And it is expected that the future study can provide statistically more meaningful econometric results if it can obtain data during more long-periods and use more various kinds of explanatory variables.

• Journal of Korea Port Economic Association
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• v.38 no.2
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• pp.11-30
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• 2022

Korean ports have some problems in the aspect of quality & quantity in the bunkering process. Quality of bunker is assessed as more higher than competing ports. However, quality of bunkering procedure is assessed as lower. Especially, supply chain from loading of bunker to the bunker barge at oil terminal, transport it, and supply it to the ship has not been secured. Furthermore, aspect of quantity of bunker is more serious rather than that of quality of bunkering process. Disputes on the quantity of bunker between seller and buyer occur frequently, and residue & theft of bunker is also popularized issue and serious problem. Low bunkering fee is recognized as major reason of that problem, however, though low fee can be solved, it can not be necessary secured that problem could be solved, Therefore, this paper investigates and suggests the scheme to solve the quality problems of bunker supplying procedure, and develop solution toward advanced bunkering ports through removal of the quantity disputes. Concretely, this paper suggests introduction of quality system of bunker supply chain in the aspect of bunker supply procedure, and diversion from conventional sounding method to innovative Mass Flow Metering System in the aspect of bunker measuring. These two innovative solutions contribute to the removal and improvement of current structural problems in bunkering procedure.

• Journal of Korea Port Economic Association
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• v.33 no.1
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• pp.75-87
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• 2017

The purpose of this study is to utilize the system dynamics to carry out a medium and long-term forecasting analysis of the bunker price. In order to secure accurate bunker price forecast, a quantitative analysis was established based on the casual loop diagram between various variables that affects bunker price. Based on various configuration variables such as crude oil price which affects crude oil consumption & production, GDP and exchange rate which influences economic changes and freight rate which is decided by supply and demand in shipping and logistic market were used in accordance with System Dynamics to forecast bunker price and then objectivity was verified through MAPEs. Based on the result of this study, bunker price is expected to rise until 2029 compared to 2016 but it will not be near the surge sighted in 2012. This study holds value in two ways. First, it supports shipping companies to efficiently manage its fleet, offering comprehensive bunker price risk management by presenting structural relationship between various variables affecting bunker price. Second, rational result derived from bunker price forecast by utilizing dynamic casual loop between various variables.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.384-388
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• 1988

A marine bacterium Achromobacter sp. M-1220 was isolated from enrichment culture for emulsification of Bunker-C oil. The bacterium can emulsify approximately 7.5g of Bunker-C oil per liter in sen water medium within 1 drys at 18$^{\circ}C$ and multiply from 8$\times$10$^5$ cells to 9$\times$10$^9$ cells per mi. Optimum pH and salt concentration were pH 7.5 and 3% for the emulsification of Bunker-C oil. Emulsification takes place actively in both high sulfur-containing Bunker-C oil and high sulfur-con-taming crude oil. The amount of emulsification depends on the exogenous addition of nitrogen and phosphate sources. The bacterium can also utilize n-hexndecane, n-paraffin me benzene among the petroleum compounds as a sole carbon source.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.859-867
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• 2016

Bunker oil is an essential expense, and it is a high cost in ships' operations. Therefore, it forms an important part of the work shipowners do to minimize losses during operations. With bunkering disputes consistently occurring, bunker surveyors could be employed by shipowners through them and bunker survey companies signing a contract for a bunker surveyor service. Bunker surveyors could play the role of independent contractors and issue statements of fact in relation to bunkering. However, it would be impossible for bunker surveyors to immediately resolve a bunkering dispute since their role and the legal status is not clear while bunker surveys are being conducted on ships. Thus, this study sets out to define the legal status and liability of bunker surveyors and to seek an additional role for them when bunkering disputes occur.