• 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.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.31-34
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• 1990

Dibenzothiophene, crude oil and bunker C oil were used in the microbial desulfurization experiments using thermophilic and mesophilic strains of Desulfovibrio and Desulfotomaculum. Mesophilic Desulforvibrio desulfuricans M6 showed the degrees of sulfur removal about 42% and 17% from dibenzothiophene and crude oil, respectively. Thermophilic Desulfovibrio thermophilus showed the degrees of sulfur removal about 68% and 33% from dibenzothiophene and bunker C oil. The strains of Desulfotomaculum were much less efficient than strains of Desulfovibrio. The latter have more complex and stronger gydrogen metabolism. These results showed that desulfurization is closely related to the hydrogen metabolism of the sulfate reducing bacteria.

• 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.

• 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 Korean Society for Atmospheric Environment
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• v.31 no.4
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• pp.368-377
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• 2015

Bunker C fuel oil is a high-viscosity oil obtained from petroleum distillation as a residue. The sulfur content of bunker C fuel oil is limited to 4.0% or even lower to protect the environment. Because bunker C fuel oil is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, carbon dioxide is emitted as a result of combustion. The objective of this study is to investigate $CO_2$ emission characteristics of bunker C fuel oil by sulfur contents. Calorific values and carbon contents of the fuels were measured using the oxygen bomb calorimeter method and the CHN elemental analysis method, respectively. Sulfur and hydrogen contents, which were used to calculate the net calorific value, were also measured and then net calorific values and $CO_2$ emission factors were determined. The results showed that hydrogen content increases and carbon content decreases by reducing sulfur contents for bunker C fuel oil with sulfur contents less than 1.0%. For sulfur contents between 1.0% and 4.0%, carbon content increases as sulfur content decreases but there is no evident variation in hydrogen content. Net calorific value increases by reducing sulfur contents. $CO_2$ emission factor, which is calculated by dividing carbon content by net calorific value, decreases as sulfur content decreases for bunker C fuel oil with sulfur contents less than 1.0% but it showed relatively constant values for sulfur contents between 1.0% and 4.0%.

• 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.34 no.2
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• pp.145-150
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• 2001

A marine bacterium having a high oil-degrading activity was isolated from the coastal water of Yosu, Korea, identified as Pseudomonas sp. and named Pseudomonas sp. BCK-1. The optimal temperature, pH and NaCl concentration for cell growth was $30^{\circ}C$, 7.0 and $3\%$ (w/v), respectively. After cultivation at $30^{\circ}C$, 180 rpm in 250 mL erlenmeyer flask for 72 and 168 hours, $2\%$ (w/v) arabian light crude oil (ACO) and bunker C oil (BCO) which are considered to be hardly biodegradable compounds were degraded $92\%$ (w/w) and $72\%$ (w/w), respectively.

• 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.

• Journal of Adhesion and Interface
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• v.3 no.2
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• pp.1-8
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• 2002

Polyurethane NCO prepolymers were synthesized with the polyols such as PTMG, GP and the isocyanate such as TDI at $40^{\circ}C$ for 8.5 minutes. As average molecular weights (${\bar{M_n}}$: 1000, 2000, 3000, 4000) of PTMG, and GP were decreased from 4000 to 1000, ratio of oil gelation increased from 298%, to 440%, for Bunker B. When oil and water were emulsified, the ratio of gelation was increased approximately two times. Ratio of gelation for emulsive Bunker B was increased from 402% to 910%, for PTMG1000 and increased from 440%, W 958% for GPI1000. Ratio of oil gelation for emulsive Bunk C which has higher viscosity than Bunker B was measured w 923% for PTMG1000 made with chain extender, i.e. EG, and measured to 1098% for GP1000. The gel made from GP which has three functional group showed soft and strong characteristic, as a result, it can be removed easily from oil spilled ocean.

• Journal of the Korean Professional Engineers Association
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• v.4 no.15
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• pp.11-15
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• 1971

Bunker C fuel oil may be taken as a conc. solution of asphalt as a solute. It may be assumpt that there will be unalogical relationship between cone. solution and solute in regological behavior. Investigation was carried out to fiud out the -opitimum preheating temperature. The following results were obtained: the colloidal structure bunker C fuel oil undergoes a transition at around the softening point of the solute asphalt: and the flow charactor changes from non-Newtonian flow to Newtonian as well as its activation energy is memarkably reduced at around softening point of the solute asphalt for the purpose of the improvement of flow charater of Bunker C fuel oil, the preheating must be done above the softening point of a solute asphalt.