• Elastomers and Composites
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• v.39 no.1
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• pp.61-70
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• 2004

This work is about the development or asphalt sealant using the waste edible oil. Asphalt sealant has been used for crack filler and bridge deck joint sealer Several plasticizers such as aromatic or paraffin process oils, DOP, Bunker C fuel oil, and waste edible oil were compounded with the basic components such as asphalt(AP-5), a thermoplastic elastomer(SBS triblock copolymer), a tackifying agent(petroleum resin), and stabilizers. Penetration, softening point, ductility, and elongation by tensile adhesion of those asphalt sealant compounds were measured. Their properties were changed largely depending on both the type and content of plasticizers. Waste edible oil and DOP were the best plasticizers for the low temperature tensile adhesion characteristics. Penetration and elongation by tensile adhesion of asphalt sealant compounds increased with the increase of waste edible oil content and decreased with the increase of talc content. The manufacture of asphalt sealant with low penetration and excellent low temperature tensile adhesion was possible by the recipe optimization.

• Plant Journal
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• v.12 no.3
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• pp.39-45
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• 2016

Each of fuel consumption per hour was measured at the 320 MW and 380 MW generator output while changing mixing ratio of bio fuel oil to 50%, 80% and 100%. Fuel consumption per hour was increased from 11.0% to 20.4% as mixing ratio of bio fuel oil was changed from 50% to 100% at the 320 MW generator output comparing with fuel consumption per hour in case of bunker-C oil single firing. Fuel consumption per hour was also increased from 12.0% to 21.1% as mixing ratio of bio fuel oil was changed from 50% to 100% at the generator output 380 MW. Furthermore, it was confirmed that plant efficiency was decreased as mixing ratio of bio fuel oil was increased from 50% to 100% as a result that plant efficiency was calculated using the measured fuel consumption per hour, the generator output and the gross heating value.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.2
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• pp.662-670
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• 2019

Tanker cargo tanks are equipped with the means of raising and maintaining the cargo discharge temperature to a suitable level. In this paper, a new heating coil design is proposed and analyzed. Contrary to conventional designs, wherein the heating coils are evenly distributed over the tank bottom, the proposed design arranges the heating coils in the central part of the tank bottom, in a vertical direction. Due to the intensive cargo circulation generated, a forced convection is superimposed on a buoyancy-driven natural convection, providing a more efficient mixed convection heat transfer mechanism. Numerical simulations performed by using a finite volume method show that in the case of 7-bar steam Bunker C heavy fuel oil heating, a five-hour circulation phase average heat transfer coefficient equals 199.2 W/m²K. This result might be taken as an impetus for the more thorough experimental examination.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.600-604
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• 2003

This study pointed at isolation of bunker-C oil degrading bacteria and then estimation of it's degrading capability in environmental conditions. Degradation ratio of the excellent isolate was appeared to 40.5% and 44.7% when the oil was treated to 1% and 5%, respectively. The isolate was identified to Acinetobater calcoaceticus SEBCM. In pH test, high degrading effect was appeared to about 73% at pH 6 and pH 7, and low degrading ratio was 37% at pH 4. Its growth condition at temperature has not large variation in $15^{\circ}C\;{\sim}30^{\circ}C$, Quantity of nitrogen for it's good growth was ranged of $0.5\;g/L{\sim}2\;g/L$. As these results, we realized that this isolate have good activity when treated to $15\;{\sim}30^{\circ}C$ of temperature and $6{\sim}7$ of pH.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.2
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• pp.208-215
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• 2017

When persistent oil, such as crude oil or Bunker C oil, is spilled at sea, viscosity increases through the weathering process. Equipment that can collect this oil when mixed with floating marine debris is very limited. In this study, devices that can be attached to the outside of existing oil skimmers have been applied to the inside of the main body, to develop an unmanned conveyor belt type floating marine debris and high viscosity oil recovery skimmer, which is composed of a conveyor belt, a sweeper with a forced inflow device, and a collection tank equipped with a buoyant body. The resulting skimmer was operated at a speed of 1.2 knots at a distance of 30 m in a sea area test. It was stable when moving laterally in any direction. An oil recovery performance test was conducted using a portable storage tank, and oil was recovered from a minimum of $7.8k{\ell}/h$ to a maximum of $23.3k{\ell}/h$. Moreover, recovery of $7.7k{\ell}/h$ was obtained in a wave water tank test with floating marine debris such as PET bottles and oil mixed. If the equipment developed in this study was used in the field for oil pollution accidents, it could be expected to contribute to improved response capability. We believe our equipment could be used in further studies to improvement the performance of existing portable oil skimmers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.528-535
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• 2016

Two types of oleophilic acrylic prepolymers were prepared by the solution copolymerization of either ethyl acrylate (EA) or lauryl acrylate (LA) with hydroxy ethyl acrylate (HEA). For the formation of oil-absorbent materials, a mixed solution of the prepolymer and hexamethylene diisocyanate (HDI) as a cross-linker in toluene was applied to polypropylene knit velvet fabric through the conventional pad-dry-cure procedure. The gel fraction of the crosslinked resin, EA-HEA-HDI, increased with increasing feed ratio of HEA to total acrylate or HDI concentration. The oil absorbancy and retention ratio of the prepared materials were compared according to the add-on ratio of resin to fabric, and were assessed with n-decane, toluene, soybean oil, lubricant and bunker C oil as test oils. The optimal oil absorbancy of the materials were observed at around 6% of the add-on ratio for all these oils except for soybean oil. On the other hand, the oil retention ratio increased as the add-on ratio increased. Futhermore, heavier and more viscous oil generally showed higher oil retention ratios. In addition, the oil absorbancy of the materials treated with LA-HEA-HDI resin was higher than that treated with EA-HEA-HDI resin, which showed that the acrylic resins are more absorptive with increasing length of their side alkyl chain.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.965-971
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• 2017

The primary objective of this study was to assess the energy efficiency performance of an optimized hull form capable of saving energy based on existing vessels. The bow shape of existing vessels was investigated, giving consideration to design draft and speed. Resistance performances were also assessed for existing vessels according to operating conditions. Commercial CFD codes and model test materials were used to assess effective power. An optimized hull form with minimum resistance was selected given real operating conditions. The effective horsepower of existing and optimized vessels was estimated at three speeds. Resistance performance for an optimized vessel showed a 6 % improvement in effective horsepower at design speed (12 knots) compared to existing vessels. Quasi-propulsive efficiency employed experimental data, while energy efficiency performance was analyzed based on operating days, bunker fuel oil C cost, daily fuel oil consumption and specific fuel oil consumption. Energy efficiency performance for an optimized vessel showed a gain of 30 million won per year in reduced costs at design speed (12 knots) compared to existing vessels.

• Journal of the korean society of oceanography
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• v.33 no.4
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• pp.168-177
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• 1998

Five and a half months after the Keumdong oil spill accident on the 21$^{st}$ of September 1993, 34 seawater samples and 94 sediment samples were collected from Kwangyang Bay and Namhaedo area to assess its environmental impacts. Hydrocarbon concentration in the seawater ranged from 0.8 to 9.2 ${\mu}$g/1 with an average of 3.3 ${\mu}$g/1. This average value was nearly the same as the value(3.7 ${\mu}$g/1) before the oil spill accident. This suggests that by the early March of 1994 majority of the coastal water in the study area restored to its background hydrocarbon concentration before the oil spill accident. Nutrients, heavy metals and other general environmental parameters of the seawater did not show any aggravated seawater quality compared with the previous records. From the regression analysis of time-course observation of hydrocarbon in the seawater, except the sediment environment, the effect of oil spill on the water column was estimated to last at least 4 months in the study area after the oil spill accident. In the shoreline sediments, oil deposits were, however, still found at the high water marks at several stations, and very high values were found in the west of Namhaedo, ranging from 3.7 to 40.1 mg/g of wet sediment. Gas chromatography of these samples showed a very distinct Bunker C chromatogram identical to the Keumdong oil spill. Hydrocarbons in the subtidal bottom sediments in the study area and the reference stations (YB and CB) ranged from 0.45 to 18.08 ${\mu}$g/g of wet sediment with an average of 3.09 ${\mu}$g/g. West of Namhaedo (Stations Bl2-B33) generally showed much higher values than inner Kwangyang Bay and in Chinju Bay. Chinju Bay generally showed the lowest value among the study area. Subtidal bottom sediments in inner Kwangyang Bay and Chinju Bay seemed to be less affected than west of Namhaedo. Heavy metal concentrations in the sediment were relatively higher in the Kwangyang Bay than in the Chinju Bay. However, metal concentrations in the study area were in general comparable to the reference areas.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.174-190
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• 1996

Damage assessment based on in situ surveys for oil spills in marine environment is limited by fundamental difficulties as well as tremendous expenses. Except for intertidal zones, the damage is not preserved well. Also such surveys are usually confined to adult organisms. To overcome these limitations a computer model, NRDAM/CME, was developed in the case of USA (Reed et al., 1989), where an acute toxicity data base was used to assess indirect damages through food webs and loss due to recruitment as well as adult losses. In the present study damage assessment of natural biological resources for hypothetical oil spills is attempted using a computer model for hypothetical spills of Bunker C and heavy crude oil. In the model, the logical structure of NRDAM/CME was adopted, and biomass and productivity database were compiled for the Korean waters. The results showed that the damage increased in a nonlinear fashion as the spill amount increased. The magnitude of the damage depended upon the chemical properties of oil viscosity and solubility in particular, which implies that usage of oil dispersant might increase the damage by dispersing oil. The results also indicate that long term damage due to recruitment loss could be greater than short term damage.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.4
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• pp.49-60
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• 2019

Recently the concentration of fine dust and ultra fine dust becomes so bad, which seriously threatens the health and even the life of people. So, government started to investigate several ways to reduce the amount of fine dust and ultra fine dust. From a few years ago it has been known that ships anchored at port emit a lot of pollution and seriously affect air quality of neighboring cities. To reduce the pollution emitted by ship AMP (Alternative Maritime Power Supply) has been proposed, which uses the electricity instead of bunker C oil or diesel. Many developed countries already installed AMP to improve air quality in port area. Korea is in the stage of planning to install AMP at port. However, there are many complicated problems to be handled before AMP installation. Due to huge initial cost and long period of construction ship owner and habour operating company are reluctant to AMP installation. And there are serious technological difficulties in constructing AMP in existing harbour. Lack of AMP core technology and operational difficulties of AMP are also big challenges to be conquered. In this study SWOT/AHP method is used to find strategic and efficient ways to handle above complicated challenges and then to vitalize the AMP installation.