• Ocean and Polar Research
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• 제27권4호
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• pp.451-461
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• 2005

The $CO_2$ storage in geologic and oceanic reservoirs is considered to be one of the carbon management strategies for responding to global climate change. Ocean carbon sequestration is purposeful storage acceleration into the ocean of large amounts of carbon that would accumulate in the atmosphere and naturally enter the ocean over a longer timespan. Some technologies for $CO_2$ ocean sequestrations have been developed as a nation project. However, $CO_2$ ocean sequestrations are attractive because they have the advantage of vast capacity sequestration far away from industrial areas, and offer easier monitoring whereas less economic advantage has been indicated as one of the key barriers compared with $CO_2$ geosphere sequestration, which is produced as a byproduct. In this paper, a conceptual design for $CO_2$ ocean sequestration is introduced, and the preliminary examination is described. As a result, the $CO_2$ price, US$ 24/t shows far away from the economics. The causes come from the expensive $CO_2$ recovery cost and the low $CO_2$ price. The expensive $CO_2$ recovery cost is because too much electricity and water are consumed. In order to look for an economic balance point for $CO_2$ ocean sequestration, NPV=0, it is increases the $CO_2$ price. Finally 60.4$ per ton is found to be the balance price.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.265-268
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• 2006

The preliminary design of a deep-sea injection system for carbon dioxide ocean sequestration is performed. Common functional requirements for a deep-sea injection system of mid-depth type and lake type are determined, Liquid transport system, liquid storage system and liquid injection system are conceptually determined for the functional requirements. For liquid injection system, the control of flow rate and temperature of liquid $CO_2$ in the injection pipe is needed in the view of internal flow. The function of depressing VIV(Vortex Induced Vibration) is also required in the view of dynamic stability of the injection pipe. A case study is performed for $CO_2$ sequestration capacity of 10 million tons per year. In this study, the total number of injection ships, the flow rate of liquid $CO_2$ and the configuration of a injection pipe are designed. The static structural analysis of the injection pipe is also performed. Finally the preliminary design of a deep-sea injection system is proposed.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.196-201
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• 2009

Global warming issues due to the $CO_2$(Carbon Dioxide) become increasing since the Industrial Revolution. After the Kyoto protocol at 1997, nations which have the prearranged quota drives their national project for the reduction of $CO_2$. Korean Government start to the related big projects in the view of three concepts which have consist of the $CO_2$ exhaust reduction on land, $CO_2$ capture and $CO_2$ storage. Furthermore, the storage method putting into depleted region underground is accepted by the London Convention while the ocean diluted method discharging the liquid $CO_2$ into the deep ocean using the long pipe which is towed by the surface vessel is underway for the research steps which means that there are many potentials for the R&Ds that need for the breakthrough. In this paper, the role and example of the Computational Fluid Dynamics for the feasibility study of the $CO_2$ ocean sequestration is mentioned.

• Ocean Systems Engineering
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• 제10권3호
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• pp.317-332
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• 2020

This study examines the behaviors and properties of discharged liquid CO₂ from a long elastic pipe moving with a vessel for the oceanic CO₂ sequestration by considering pipe dynamics and vessel motions. The coupled vessel-pipe dynamic analysis for a typical configuration is done in the frequency and time domain using the ORCAFLEX program. The system's characteristics, such as vessel RAOs and pipe-axial-velocity transfer function, are identified by applying a broadband white noise wave spectrum to the vessel-pipe dynamic system. The frequency shift of the vessel's RAO due to the encounter-frequency effect is also investigated through the system identification method. Additionally, the time histories of the tip-of-pipe velocities, along with the corresponding discharged droplet size and Weber numbers, are generated for two different sea states. The comparison between the stiff non-oscillating pipe with the flexible oscillating pipe shows the effect of the vessel and pipe dynamics to the discharged CO₂ droplet size and Weber number. The pipe's axial-mode resonance is the leading cause of the fluctuation of the discharged CO₂ properties. The significant variation of the discharged CO₂ properties observed in this study shows the importance of considering the vessel-pipe motions when designing oceanic CO₂ sequestration strategy, including suitable sequestration locations, discharge rate, towing speed, and sea states.

• Journal of Mechanical Science and Technology
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• 제19권5호
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• pp.1216-1225
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• 2005

$CO_{2}$ ocean sequestration is one of the promising options to reduce $CO_{2}$ concentration in the atmosphere because the ocean has vast capacity for $CO_{2}$ absorption. Therefore, in the present investigation, calculations for solubility and dissolution behavior of liquid $CO_{2}$ droplets released at 1000 m and 1500 m deep in the ocean from a moving ship and a fixed pipeline have been carried out in order to estimate the $CO_{2}$ dissolution characteristics in the ocean. The results show liquid $CO_{2}$ becomes bubble at around 500 m in depth, and the solubility of seawater is about $5{\%}$ less than of pure water. Also, it is shown that the injection of liquid from a moving ship is a more effective method for dissolution than from a fixed pipeline, and the presence of hydrate on liquid $CO_{2}$ acts as a resistant layer in dissolving liquid $CO_{2}$.

• 한국해양환경ㆍ에너지학회지
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• 제8권3호
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• pp.111-115
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• 2005

화석연료소비로 인하여 대기 중의 온실가스농도가 계속해서 증가하고 있는 추세이며, 이에 따른 기상이변, 생물다양성감소와 해수면 상승등 예상치 못한 기후 변동이 계속 발생하고 있다. 본 기술논문에서는 온실가스의 대부분을 차지하는 $CO_2$를 심해양(2,000 m이상)에 친환경적으로 처리하는 기술(심해분사법, 해저저류법, 해저지중처리법)에 대해 비교연구를 수행하였다. 뿐만아니라 $CO_2$ 처리기술의 유효성 평가, $CO_2$ 처리기술의 환경영향 평가기술, $CO_2$ 해양처리에 관한 국제법적, 사회적 수용여부와 국내 연구방향 및 기대효과등에 관하여 논하였다.

• 한국해양환경ㆍ에너지학회지
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• 제8권4호
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• pp.203-212
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• 2005

온실기체의 인위적 배출은 지구온난화를 유발하여 해수면 상승, 극 기상 등 전 세계에서 피해가 증가하고 있다. 특히, 지구온난화 기여도가 가장 높은 온실기체 중 이산화탄소($CO_2$)는 주로 화석연료의 사용 공정에서 발생하는 폐기물이다. 대기 중의 이산화탄소의 농도 증가는 표층 해양을 산성화시켜 표층해양 생태계, 나아가서는 지구 전체 생태계에 악영향을 미치게 될 것으로 보인다. 이산화탄소 배출량을 줄이기 위해서 에너지 효율을 높이거나 대체 에너지를 이용하는 등의 완화 기술이 동원 되고 있다. 그러나 현재 세계 에너지 수요의 약 85%가 화석연료로 충당되고 있기 때문에, 화석연료 이외의 대체 에너지원으로 급격히 전환한다면 세계 경제에 엄청난 충격이 올 것이다. 다행히도 최근 이산화탄소를 포집하여 지질구조에 격리하는 기술이 개발단계를 지나 실용화단계로 성숙하였다. 이 방안으로 단기간에 온실기체의 대기로의 배출량을 대규모로 줄일 수 있다(이상 2005년 런던협약 과학그룹회의록에서 발췌). 우리나라의 경우는 이산화탄소를 격리시킬 수 있는 장소는 육상면적이 작고 인구 밀도가 높아서 육상보다는 해양저지질구조가 선호될 수밖에 없을 것으로 보인다. 해양 이용은 해양의 특성상 런던협약 등의 국제적인 규제를 받게 된다. 본고는 해저 지질 구조에 대한 이산화탄소의 격리 관련 기술 및 제도의 국제동향을 우리나라 입장에서 예비적으로 검토하였다.

• 한국해양환경ㆍ에너지학회지
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• 제8권1호
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• pp.39-45
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• 2005

2004년 11월 러시아의 교토의정서 비준에 의하여 2005년 2월에 교토의정서의 발효를 앞두고 있다. 따라서 1차 감축대상국은 2008년부터 2012년까지 1990년 대비 각 국가당 설정된 GHG(Green House Gas)배출량을 감축해야하는 상황에 처해 있다. 본 논문에서는 대기 중에 뿜어내는 GHG중 가장 많은 비율을 차지하는 CO₂를 심해에 친환경적으로 처리하는 기술로서 해양격리기술에 대해 소개한다. 본 해양격리기술은 4개의 주요단계로 구분할 수 있는데, 해양수송기술, 해양분사기술, 해양저장효율평가기술, 해양처리생태영향 평가기술등으로 나눌 수 있다. 본 논문에서는 CO₂의 해양 분출시에 초기희석율에 영향을 미치는 해양분사기술 중, 액포의 거동과 용해에 관한 기초 연구를 수행하였다. 특히 본 연구에서는 전산유체역학 기법 (Computational Fluid Dynamics)을 통해 해수를 연속상(Continuous phase), 액적을 분산상(Disperse phase)으로 한 이상(Two-phase) 유체를 3차원 이동형 비구조 격자와 유한체적법을 이용하여 상 경계면이 거동하면서 거동에 따른 용해도의 변화를 추정하였다 따라서, 본 연구는 액적의 거동과 용해도의 유체역학적 관계를 밝히는 데 기초적 자료가 될 것으로 판단된다.

• 설비공학논문집
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• 제15권9호
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• pp.718-726
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• 2003

Carbon dioxide ocean disposal is one of the promising options to reduce carbon dioxide concentration in the atmosphere because the ocean has vast capacity for carbon dioxide sequestration. However, the dissolution rate of liquid carbon dioxide in seawater must be known in advance in order to estimate the amount of carbon dioxide sequestration in the ocean. Therefore, in the present study, calculations of the solubility, the surface concentration and the dissolution behavior of carbon dioxide when liquid carbon dioxide is released at 1,000m and 1,500m in depth are peformed. The results show that the droplet is completely dissolved below 500 m in depth if the carbon dioxide droplet is released both at 1,000m in depth with the initial droplet diameter of 0.011m or less and at 1,500m in depth with the diameter of 0.016 or less. Also, the surface concentration of carbon dioxide droplet with the hydrate film is about 50% of carbon dioxide solubility at 1,500 m in depth and about 60% of carbon dioxide solubility at 1,000 m in depth.

• 설비공학논문집
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• 제18권3호
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• pp.270-278
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• 2006

The idea of carbon dioxide sequestration in the ocean is proposed to be an effective mitigation strategy to counteract potential global warming due to the greenhouse effect. Therefore, in the present study, calculations of the dissolution behavior of carbon dioxide when liquid carbon dioxide is released at 1,000m and 1,500 m in depth. by fixed pipeline are peformed. The results show the liquid $CO_2$ injected in the ocean becomes $CO_2$ bubble at between 350m and 500m in depth, and the injection from a moving ship is a more effective method of dissolution than through a fixed pipeline. It so also noted that the ultimate plume generated from $CO_2$ bubbles repeats expansion and shrinking due to the peeling from a fixed pipeline.