• Journal of the Korean Applied Science and Technology
• /
• v.33 no.4
• /
• pp.676-685
• /
• 2016

This study investigated the conversion of oil products from polystyrene by using dispersed Co and Mo catalyst on reaction time and concentration change for knowledging on characteristics at low temperature (425, 450 and $475^{\circ}C$) pyrolysis and reaction time(20~80 min, 15 min interval) in a batch reactor. It will be showed the conditions for optimum pyrolysis at reaction temperature $450^{\circ}C$ and the reaction time 35min, and the main components of the converted liquid oil were styrene and benzene derivatives by GC/MS. The oil products formed during pyrolysis were classified into gas, gasoline, kero, diesel and heavy oil according to the domestic specification of petroleum products. The pyrolysis conversion rate was showed as Co catalyst > Mo catalyst > Thermal in all reaction time at reaction temperature $450^{\circ}C$. The yields rate of gas, kerosine, diesel were the most hight at Mo Catalyst, gasoline was at thermal and heavy oil was at Co catalyst. The conversion rate and yields of the pyrolysis products were the most height when Co catalyst ratio was 100%.

• Plant Journal
• /
• v.9 no.3
• /
• pp.38-42
• /
• 2013

Submarine gas fields have focused because of the increasing fuel cost, the environmental regulations, and the safety & NIMBY problems. LNG-FPSO which is available for acid gas removal, recovery of the condensate & LPG and Liquefaction in topside process is one of high technology offshore structures. On the other hands, it is necessary to verify the pre-treatment efficiency by the ship motion and to apply to the design for LNG-FPSO. This study is to develop the pre-treatment technology for LNG-FPSO as taking account to the process efficiency by ship motion effects and the area optimization. Based on the simulation results, it founds that hybrid process shows the low circulate rate, the low heat duty and the small size of column dimensions compared to typical amine process. It will be verified the process efficiency in the various conditions by sea states as performing the 6-DOF motion test and CFD simulation.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.6 s.52
• /
• pp.67-77
• /
• 2006

Seismic activity of Korea is not so high as that of Japan or California and most of the structures were designed without considering the influence of earthquakes until the first seismic design code was enforced in 1988. Therefore, it was very hard to find seismically isolated structures in Korea until 1980's. Korean engineers assumed that the seismic isolation or vibration control would be useful only in a high seismicity region while such technologies can be quite useful in a low seismicity region for the efficient reduction of earthquake damages. Recently, Korean engineers began to have interest in the seismic isolation or vibration control and applied it to some important structures such as LNG storage tanks, many bridges and several buildings. However, design codes are not defining such useful advanced technologies for the design of building structures and several projects employing seismic isolation or vibration control in the design of structures had difficulties in obtaining construction permit from the local government. Therefore, it is an urgent requirement to introduce these advanced technologies in the seismic design code.

• Transactions of the Korean hydrogen and new energy society
• /
• v.33 no.6
• /
• pp.808-818
• /
• 2022

In this research paper, we investigated the cryogenic line chill down characteristics of liquefied natural gas (LNG). A numerical analysis model was established and verified so that it can calculate the precise cooling characteristics of cryogenic fluid for the stable and safe utilization especially such as LNG and liquid hydrogen. The numerical modeling was programmed by C++ as an one-dimensional homogeneous model. The thermohydraulic cooling process was simulated using mass, momentum, energy conservation equations and appropriate heat transfer correlations. In this process, the relevant heat transfer correlations for nuclear boiling, transition boiling, film boiling, and single-phase heat transfer that can predict the experimental results were implemented. To verify the numerical modeling, several cryogenic line chill down experiments using LNG were conducted at the Korea Institute of Machinery & Materials (KIMM) LNG and Cryogenic Technology Center.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.2_2
• /
• pp.333-340
• /
• 2023

Environmental regulations are being strengthened worldwide to solve global warming. For this reason, interest in eco-friendly gas fuels such as LNG and hydrogen is continuously increasing. However, when adopting eco-friendly gas fuel, liquefying at a cryogenic temperature is essential to ensure economic feasibility in storage and transportation. Although austenitic stainless steel is typically applied to store cryogenic liquefied gas, structural steel can experience sudden heat shrinkage in the case of leakage in the loading and unloading process of LNG. In severe cases, the phase of the steel may change, so care is required. This study conducted Charpy impact tests on steel material in nine different temperature ranges, from room to cryogenic temperatures, to analyze the effects of cryogenic liquefied gas leaks. As a result of the study, it was not easy to find variations in ductile to brittle transition temperature (DBTT) due to the leakage of cryogenic liquefied gas. Still, the overall impact toughness tended to decrease, and these results were verified through fracture surface analysis. In summary, brittle fracture of the steel plate may occur when a secondary load is applied to steel for hull structural use exposed to a cryogenic environment of -40 ℃ or lower. Therefore, it needs to be considered in the ship design and operating conditions.

• Tunnel and Underground Space
• /
• v.16 no.4 s.63
• /
• pp.296-306
• /
• 2006

It is difficult to solve problems regarding the adjustment on demand and supply of LNG due to seasonal variations of domestic demand of LNG, a discordance among import pattern and limits of storage facilities and so on. Also, there may be instability in LNG supply due to chances of accidents at LNG producing areas. Therefore, it is very important to secure large LNG storage facilities and to stabilize LNG supply management on a long term basis. The objective of this study is to examine the real-scale applicability of a lined underground rock storage system, which have been verified by a successful operation of the Daejeon LNG pilot plant. The new technology has many advantages of better economy, safety and environment protection, for above-ground and in-ground storage systems. The results of this study may promote the first ever real scale underground LNG storage system in a rock cavern.

• Composites Research
• /
• v.22 no.4
• /
• pp.13-19
• /
• 2009

Adhesive joints are widely used for structural joining applications in various fields and environmental conditions. Polyurethane adhesive is using for LNG carrier with cryogenic temperature condition. Even if similar polyurethane adhesive is used for different substrate, it shows different adhesion properties. Specially, variation of adhesion properties depending on the resin system or fiber is very important factor for selection of adhesive on industrial application. In present study, we got different peel strength according to the different test temperature when different polyurethane adhesive was used for same fiber reinforced composite. The main cause was investigated using by SEM and it was proven that the different adhesion property between glass fiber on composite surface and polyurethane adhesives at cryogenic temperature.

• Nuclear industry
• /
• v.38 no.2
• /
• pp.13-27
• /
• 2018

재생에너지의 활용 가능성이 제한적이고 인구 밀도가 높은 대한민국의 현실을 놓고 볼 때, 원자력은 온실가스 배출 및 공해를 줄이면서도 충분한 전력을 생산하여 공급해줄 수 있는 가장 신뢰할만한 발전 수단이다. 그러나 한국 정부는 원전과 석탄발전소를 단계적으로 폐쇄하고 이를 대체하기 위해서 다양한 재생에너지를 늘리겠다는 정책을 확고하게 고수하고 있다. 그렇지만 에너지 생산 수단을 전환하겠다는 이 정책의 주요 목표는 액화천연가스(LNG) 발전을 대체 수단으로 삼고 있다. 그 이유는 다른 재생에너지들의 대규모 생산 수단을 개발하는 데는 기술적이고 경제적인 난제들이 걸림돌이 되기 때문이다. 그러므로 미래의 에너지 정책을 결정하기에 앞서, 에너지 전환 정책의 구체적인 사항들을 확실한 근거에 기반해서 검토한 후 계획을 수립하는 것이 매우 중요한 일이다. 이 문제에 관해서 우리는 다음과 같은 점들을 검토하였다 (1) 한국이 처해 있는 기술적 경제적인 제약을 전제로 한 재생에너지원의 개발에 대한 정부의 역할, (2) 가스 발전으로 인해 발생할 수 있는 환경적이며 경제적인 문제점들, (3) 원전정책을 지속함으로써 얻을 수 있는 이점과 원전 유지에 대한 장애물. 위와 같은 세 가지 사항을 검토한 결과, 한국이 지니고 있는 지리적 경제적인 제약과 함께 탄소 배출로 인해 발생하는 비용까지 효과적으로 줄여야 한다는 점 등을 감안할 때 천연가스 발전으로 집중하겠다는 한국의 미래 에너지 정책은 친환경적이지 못함은 물론 경제적이지도 않기 때문에 적정한 비율의 재생에너지를 포함하는 원전 정책을 지속하는 것만이 현실적인 성공 가능성이 가장 높다고 보는 것이 우리의 결론이다.

• Journal of Advanced Marine Engineering and Technology
• /
• v.34 no.5
• /
• pp.632-637
• /
• 2010

Natural gas, a fossil fuel contained mostly of methane, is one of the cleanest alternative fuels. It can be used in the form of compressed gas(CNG) or liquefied natural gas(LNG) to cars and trucks. And, dedicated natural gas vehicles are designed to run on natural gas only, while Bi-fuel vehicles can also run on gasoline or CNG, especially, bi-fuel can be defined as the simultaneous combustion of two fuels. In this study, converted gasoline marine system to CNG Bi-fuel system which is made up of injector, regulator, tank and ECU is converted. And estimated the fuel system and engine power compared the result with gasoline engine is estimated. As a result, CNG engine shows low exhaust emissions but maxium power is 7% reduced compared to gasoline engine.

• Transactions of the KSME C: Technology and Education
• /
• v.1 no.1
• /
• pp.83-90
• /
• 2013

The purpose of this study is to replace existing liquid chlorine with localization of on-site high (12%) sodium hypochlorite generation system. On-site high (12%) sodium hypochlorite generation system is higher the current efficiency of 38.7%, 54.6% reduction of salt consumption, and 97.3% lower rate of chlorate than on-site low (0.8%) sodium hypochlorite generation system.