• Membrane Journal
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• v.17 no.3
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• pp.197-209
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• 2007

In this study, a multi-staged pilot-scale membrane plant was constructed and operated for the separation of $CO_2$ from LNG-fired boiler flue gas of 1,000 $Nm^3/day$. The target purity and recovery ratio of $CO_2$ required for the pilot plant were 99% and 90%, respectively. For this purpose, we previously developed the asymmetric polyethersulfone hollow fibers and evaluated the effects of operating pressure and feed concentration of $CO_2$ on separation performance[1,2]. The permeation data obtained were also analyzed in relation with the numerical simulation data using counter-current flow model[3,4]. Based on these results, we designed and prepared the demonstration plant consisting of dehumidification process and four-staged membrane process. The operation results using this plant were compared with the numerical simulation results on multi-staged membrane process. The experimental results matched well with the numerical simulation data. The concentration and the recovery ratio of $CO_2$ in the final stage permeate stream were ranged from $95{\sim}99%$ and $70{\sim}95%$, respectively, depending on the operating conditions. This study demonstrated the applicability of the membrane-based pilot plant for $CO_2$ recovery from flue gas.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.99-105
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• 2013

In this paper, we carried out the basic design of 36 MTD natural gas BOG re-liquefaction system to recover the generated natural gas during performance test of LNG pump and natural gas compressor. The re-liquefaction process of natural gas is designed to have 1500 kg/h of liquefaction rate with reverse Brayton refrigeration cycle. With the designed process, the variation of liquefaction rate is calculated for various inlet conditions of feed gas. From results, the liquefaction rate is more sensitive for inlet temperature than gas composition. The specifications of equipments such as gas blower, natural gas compressor, cryogenic heat exchanger and nitrogen compander are determined on the basis of the designed process. The requirement of power consumption and cooling water are also determined through the basic design.

• Journal of Hydrogen and New Energy
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• v.26 no.2
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• pp.192-198
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• 2015

Fault Tree Analysis to predict the lifetime in the design process of LNG compressor is considered. Fault Trees for P & ID of the compressor are created. Individual components that comprise the compressor are configured with the basic event. The failure rates in the PDS and OREDA are applied. As results, the system failure rate and the reliability over time are obtained. Further, the power transmission and the shaft seal system is confirmed to confidentially importantly contribute to the overall lifetime of the system. These techniques will help to improve the reliability of design of large scale machinery such as a plant.

• Journal of Hydrogen and New Energy
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• v.35 no.1
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• pp.90-96
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• 2024

In this paper, a new technology to obtain electronic grade, highly pure carbon dioxide by using membrane and liquefied natural gas (LNG) cold heat assisted cryogenic distillation has been proposed. PRO/II with PROVISION release 2023.1 from AVEVA company was used, and Peng-Robinson equation of the state model with Twu's alpha function to predict pure component vapor pressure versus temperature more accurately was selected for the modeling of the membrane and cryogenic distillation process. Advantage of using membrane separation instead of selecting absorber-stripper configuration for the concentration of carbon dioxide was the reduction of carbon dioxide capture cost.

• Transactions of the KSME C: Technology and Education
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• v.3 no.1
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• pp.55-62
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• 2015

The liquefaction to produce LNG (liquefied natural gas) is the only practical way for mass transportation of natural gas across oceans, which accompanies considerable energy consumption in LNG plants. Power generation is one of the effective utilization ways of LNG cold energy which evolves during the vaporization process of LNG with sea water. In this work, performance analysis of two cold energy generation processes, direct expansion and organic Rankine cycles, were carried out by using Aspen HYSYS simulation. The results show that the performance of the organic Rankine cycle is superior to the direct expansion.

• Journal of Welding and Joining
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• v.28 no.2
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• pp.27-31
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• 2010

Generally, angle pieces at the corners of cargo tank of membrane type LNG carrier ship are manually welded, due to their various shapes and positions. In this study, a GTA welding robot system was developed in order to improve productivity, which consists of a 7-axis manipulator, a system controller, a GTA welding power source, and peripheral devices. The welding system is characterized by capabilities of welding corrugated work pieces as well as 90/135 degree linear work pieces, and controlling the entire weld cycle automatically. The developed system was field tested on actual work pieces and its performance was proven to be successful.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.489-496
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• 2003

Korea Gas Corporation has recently constructed a LNG pilot tank with 1, 000㎥ capacity in Incheon, Korea. The main objective of this pilot tank construction is to accumulate field data under different operating conditions for the future use in design procedure, construction, and maintenance. As the part of the project, a field dynamic test, so-called modal test, is performed to obtain the dynamic characteristics of the pilot tank. This paper describes the instrumentation and measurement Process used in the testing. From the measured Frequency Response Functions (FRFs), resonant frequencies and corresponding mode shapes of the tank are extracted and provided. Also, these results are compared to those calculated from a finite element model. The change of dynamic characteristics of the pilot tank due to the effect of internal fluid and the possible structural deterioration will be investigated in near future.

• Journal of Hydrogen and New Energy
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• v.30 no.2
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• pp.188-192
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• 2019

Comparative studies between single- and two-stage expansion process using LNG cold heat have been performed for a closed Rankine power generation cycle. PRO/II with PROVISION release 10.0 from Schneider Electric Company was used, and the Peng-Robinson equation of state model with Twu's alpha function was selected for the modeling and optimization of the power generation cycle using LNG cold heat. In two-stage power generation cycle, 6.7% more power was obtained compared to that of single-stage power generation cycle through the optimization works.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.1
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• pp.1-9
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• 2017

LNG has significant advantages in regard to environmental aspects comparing with conventional fuel oil. In fact, it is estimated that NOx and SOx emission can be reduced by about 90% and 100%, respectively in case of using LNG as a fuel. LNG-fuelled ship has been considered to be the best option both from an environmental and an economic point of view. Along with these trends, some major shipyards and Classification Societies have started to carry out the risk-based system design for LNG-fuelled ship such as passenger ship, platform supply vessel and large container vessel etc. However, new conceptual gas fuelled ship has high risk level compared with vessel using traditional crude oil especially in view of gas explosion accident. Therefore safety area where installed fuel gas supply system is required risk based system design with special considerations. On this paper, the entire process necessary for the quantitative risk analysis was explained to meet the satisfactory safety level of gas fuelled ship.

• Journal of Hydrogen and New Energy
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• v.20 no.1
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• pp.79-85
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• 2009

In this paper, we investigated impact factors by brainstorming and survey research and calculated the weights of them using the Analytic Hierarchy Process(AHP) method in order to evaluate alternatives for supplying Liquefied Natural Gas(LNG). AHP is a useful method for evaluating multi-criteria decision making problems. We selected 3 criteria and 9 sub-criteria. According to the result in this study, the most important sub-criterion is the Government's Policy, and the second is the Province's Policy. The other side, the lowest important sub-criterion is the Investment Cost. This study may provide basic data to select the optimal alternative for supplying LNG.