• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.45-52
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• 2021

The government is converting the fuel for trucks, one of the causes of PM in Korea, form diesel to LNG. Mobile LNG station are being developed to solve the problems of insufficient charging infrastructure and facilitate the spread of LNG fuel. In this study, QRA was used th calculate the CA of the facility for a secure design prior to the development of the mobile LNG station and to predict the individual/societal risk the scenario. As a result, the danger of mobile LNG station was in ALARP.

• Journal of Electrochemical Science and Technology
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• v.1 no.2
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• pp.102-111
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• 2010

Molten carbonate fuel cell (MCFC) power plants are one of most attractive electricity generation systems for the use of biogas to generate high-efficiency ultra-clean power. However, MCFCs are considerably more expensive than comparable conventional electricity generation systems. The commercialization of MCFCs has been delayed more than expected. After being effective in the Kyoto protocol and considerably increasing the fossil price, the attention focused on $CO_2$ regression and renewable energy sources has increased dramatically. In particular, the commercialization and application of MCFC systems fed with biogas have been revived because of the characteristics of $CO_2$ collection and fuel variety of MCFCs. Better economic results of MCFC systems fed with biogas are expected because biogas is a relatively inexpensive fuel compared to liquefied natural gas (LNG). However, the pretreatment cost is added when using anaerobic digester gas (ADG), one of the biogases, as a fuel of MCFC systems because it contains high $H_2S$ and other contaminants, which are harmful sources to the MCFC stack in ADG. Thus, an accurate economic analysis and comparison between MCFCs fed with biogas and LNG are very necessary before the installation of an MCFC system fed with biogas in a plant. In this paper, the economic analysis of an MCFC fed with ADG was carried out for various conditions of electricity and fuel price and compared with the case of an MCFC fed with LNG.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.809-818
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• 2022

The number of ships using liquefied natural gas (LNG) as fuel is increasing to respond to the International Maritime Organization's (IMO) air pollutant emission regulations. At the same time, the need to expand LNG bunkering infrastructure for stable fuel supply and demand for ships is emerging. LNG bunkering is carried out in three ways: truck to ship (TTS), pipe to ship (PTS), and ship to ship (STS). In foreign countries, all three methods are being carried out, but in Korea, LNG bunkering is carried out only with the TTS method owing to the lack of infrastructure. LNG bunkering is a high-risk operation. For safe bunkering operations, the competence of the workers is extremely important, and a professional training course is required to strengthen the competence. This study was conducted to design training contents for LNG bunkering workers for fostering LNG bunkering experts and performing safe and systematic bunkering work. To this end, the current status of LNG-fueled ships and bunkering was identified, and related domestic and abroad educational contents were analyzed. In addition, opinions on the importance of educational contents were collected through expert questionnaires. Consequently, we designed training contents suitable for various training targets and divided them into basic and advanced training courses, with a duration of 4 days, and proposed. Based on the designed training contents, if additional research is conducted by sufficiently reflecting Korea's bunkering environment, it will be of great help to improve the competence of LNG bunkering workers and to foster human resources.

• Journal of Power System Engineering
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• v.22 no.1
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• pp.72-78
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• 2018

With growing concerns over air pollutions attributed to shipping activities, the international maritime organization has enacted a series of stringent regulations. In particular, MARPOL Annex IV Reg. 16 requires sulfur contents from exhaust gases of marine engines to be progressively reduced. To comply with this regulation, three feasible options have been introduced: using LNG as a marine fuel, using heavy fuel oil with the scrubber system, and using the marine gas oil (a type of low sulfur fuel oil). For the objectives of this paper, the holistic environmental impacts pertinent to these options were investigated and compared in ways that the flows of energy and emission were tracked and quantified through the life cycle of the ship. Research findings obtained from a case study with a large bulk carrier showed that the use of the scrubber system to purify heavy fuel oil would produce relatively fewer amounts of emissions attributing to global warming than other two options. On the other than, the use of LNG would be the way to operate the ship in a cleaner way in terms of reducing the acidification, eutrophication, and photochemical effects. Throughout the analysis, the excellence of life cycle assessment was proven to shift the environmental impact of marine systems from the short-term view to the long-term one.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.27-28
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• 2006

최근 LNG 연료 시장의 호황에 힘입어 LNG선들이 점차 대형화 추세에 있고, LNG선의 추진 기관 또한 경제성, 환경 영향 등의 주어진 요구 환경에 따라 다양화 되고 있다. 기존의 Steam Turbine Propulsion 외에 Conventional 2-stroke Diesel Engine 및 Dual-fuel 4-stroke Diesel Engine of LNG선의 주 기관으로서 이미 상용화 되었고, 기술적/경제적인 이유로 일반 상선의 주기관으로서는 논외에 있었던 Gas Turbine 또한 일부 Oil Major와 Gas Turbine Maker에 의해 그 적용 가능성이 논의되고 있다. 이에 따라 LNG 선에 Gas Turbine 적용 타당성, 고려 사항 및 적용에 따른 이점과 단점 등을 고찰하였다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.113-118
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• 2021

In this study, localized development of a submerged cryogenic pump for use in LNG containers is conducted with large-sized commercial vehicles as the target. The submerged pump installed in an LNG storage container is the key module that supplies fuel to the engine through the reciprocating motion of a piston. Research and development on 660-L fuel containers is performed herein. The target is to achieve a mileage of 600 km or more by applying it to major NGV vehicles worldwide. In this manner, the present study aims to verify the operating mechanisms of the major parts of currently advanced products through reverse engineering in the early development process and draw basic design data.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.19-22
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• 2007

In this study, we investigated operating characteristics of natural gas fuel processor for polymer electrolyte membrane fuel cells (PEMFCs). The fuel processor consists of a natural gas reformer, a water-gas shift reactor, a heat-exchanger and a burner, in which the overall integrated volume is exactly(exceptionally) small, namely, about 10L except outer insulation. The producted hydrogen is $1Nm^3/hr$ and the maximum thermal efficiency is ${\sim}76%$(low heating value) at full operating load. A compact and highly efficient $1Nm^3/hr$ class natural gas fuel processor was developed at UNISON is an advantage for application in residential PEMFCs co-generation systems.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.425-431
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• 2015

LNG (liquefied natural gas) is considered the best alternative eco-fuel, and many studies on the LNG fuel system have been performed to use LNG as the fuel for ships. For the LNG fuel supply system, natural gas transfers from the vaporizer to the engine in the gaseous state with a temperature of $50^{\circ}C$ and a pressure of 35MPa. Therefore, a structural safety evaluation of the double-walled pipelines considering thermal load is essential. In this article, an uniaxial tensile test for super duplex stainless steel, material for double-walled pipe, according to the annealing time was carried out to analyze the thermal effect. In addition, thermo-structural analysis of the high temperature-high pressure double-walled pipe with fixed supports that are now used widely was carried out to evaluate the structural safety. To minimize stress concentration of the connection point between the support and inner pipe, the shapes of the new type support that can slip through inner pipe were proposed, and the supports which has best structural performance was selected using the results from the thermo-structural analyses of new supports and an analysis of the whole double-walled pipeline was performed to ensure structural safety. These results can be used as a database for the design of double-walled pipelines and sliding support.

• Journal of Navigation and Port Research
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• v.47 no.1
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• pp.25-36
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• 2023

To limit greenhouse gas emissions from ships, numerous environmental regulations and standards have been taken into effect. As a result, alternative fuels such as liquefied natural gas (LNG), liquefied petroleum gas (LPG), ammonia, and biofuels have been applied to ships. Most of these alternative fuels are low flashpoint fuels in the form of liquefied gas. Their use is predicted to continue to increase. Thus, management regulations for using low flash point fuel as a ship fuel are required. However, they are currently insufficient. In the case of LNG, ISO standards have been prepared in relation to bunkering. The Society for Gas as a Marine Fuel (SGMF), a non-governmental organization (NGO), has also prepared and published a guideline on LNG bunkering. The classification society also requires safety management areas to be designated according to bunkering methods and procedures for safe bunkering. Therefore, it is necessary to establish a procedure for setting a safety management area according to the type of fuel, environmental conditions, and leakage scenarios and verify it with a numerical method. In this study, as a feasibility study for establishing these procedures, application status and standards of the industry were reviewed. Classification guidelines and existing preceding studies were analyzed and investigated. Based on results of this study, a procedure for establishing a safety management area for bunkering in domestic ports of Korea can be prepared.

• Journal of the Korean Institute of Gas
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• v.11 no.1 s.34
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• pp.51-54
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• 2007

78-cell proton exchange membrane fuel cell(PEMFC) stack with an effective electrode area of $295cm^{2}$ were investigated its operational characteristics and effects of CO poisoning. When power output, 5.4 kW, was released at current density of $325mA/cm^{2}$ for 6 hours, stablility of each cell was showed the small deviation of 2.3%. Carbon monoxide is a conventional contaminant in the fuel obtained from reforming processes with an important influence on the performance of the PEMFC. The studies of continuous injection of CO presented (5-20 ppm) with the time gave information about poisoning and recovery processes of the stack.