• Korean Journal of Materials Research
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• v.10 no.10
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• pp.715-720
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• 2000

By the mechanical alloying method. Ni-WC composite materials were prepared to improve the deformation-resistance for creep and sintering of Ni-anode at the operating temperature of $650^{\circ}C$. Mechanically alloyed powder w was initially fabricated by ball milling for 80hr, and then amorphization was occurred by the destruction of ordered crystals based on XRD analysis. In order to investigate the electrochemical performance and sheet characteristics of Ni-WC anode, tape casting process was adopted. Finally, the obtained sheet thickness of Ni- we after sintering at $1180^{\circ}C$ for 60 minutes in $H_2$ atmosphere was O.9mm and the average pore size was $3~5{\mu\textrm{m}}$ with porosities of 55%. The second phase was not observed in Ni- W matrix while W particles were finely and uniformly distributed in Ni matrix. This fine and uniform distributed W particles in Ni matrix are expected to enhance the mechanical properties of Ni anode through the dispersion and solid solution hardening mechanisms.

• Plant Journal
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• v.15 no.2
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• pp.42-45
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• 2019

The molten carbonate fuel cell has a high temperature of waste heat and can constitute a bottoming cycle to increase the efficiency. Previous study used a bottoming cycle as steam turbine cycle. In this study, we are going to replace the bottoming cycle with a supercritical carbon dioxide power cycle. The system power was compared to consider replacing the bottoming cycle. As a result, the power of the supercritical carbon dioxide power cycle at the present development stage is lower than that of the steam turbine cycle, but theoretically, the power can be larger than the steam turbine cycle. If the supercritical carbon dioxide power cycle improves the isentropic efficiency of the turbine by 89%, the isentropic efficiency of the compressor by 83%, and the effectiveness of the recuperator by 0.9, the power can be same to the steam turbine cycle.

• Clean Technology
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• v.26 no.4
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• pp.329-335
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• 2020

Methanol synthesized from renewable hydrogen and captured CO2 has recently attracted great interest as a sustainable energy carrier for large-scale renewable energy storage. In this study, molten carbonate fuel cell's performance was investigated with the direct conversion of methanol into syngas inside the anode chamber of the cell. The internal reforming of methanol may significantly improve system efficiency since the heat generated from the electrochemical reaction can be used directly for the endothermic reforming reaction. The porous Ni-10 wt%Cr anode was sufficient for the methanol steam reforming reaction under the fuel cell operating condition. The direct supply of methanol into the anode chamber resulted in somewhat lower cell performance, especially at high current density. Recycling of the product gas into the anode gas inlet significantly improved the cell performance. The analysis based on material balance revealed that, with increasing current density and gas recycling ratio, the methanol steam reforming reaction rate likewise increased. A methanol conversion more significant than 90% was achieved with gas recycling. The results showed the feasibility of electricity and syngas co-production using the molten carbonate fuel cell. Further research is needed to optimize the fuel cell operating conditions for simultaneous production of electricity and syngas, considering both material and energy balances in the fuel cell.

• Journal of the Korean Electrochemical Society
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• v.6 no.3
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• pp.178-182
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• 2003

The oxygen reduction and NiO dissolution behaviors in Li-Na-K three component carbonate melts have been investigated with various compositions through electrochemical and chemical ways. The oxygen reduction currents and NiO solubilities were measured at $650^{\circ}C$ and atmospheric condition in Li-Na-K =47.4-32.6-20, 60-20-20, 50-40-10, $40-40-20 mol\%$ carbonate melts. The oxygen reduction currents showed dependence on the composition, indicating oxygen solubility is a function of carbonate composition. At the composition of $ Li-Na-K=50-40-10 mol%$, a broader peak was observed, suggesting different oxygen reduction mechanism probably prevails in this composition. In contrast, insignificant differences of NiO solubility were obtained among the compositions.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.88.1-88.1
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• 2010

In recent days, the study for the renewable energy is required to supplement traditional energy source. One of the renewable energy of Fuel Cell is classified according to the electrolytes. It is the MCFC (Molten Carbonate Fuel Cell) for this study. One of the equipments of the heat exchangers is important component for efficiency and cost. In MCFC system, several heat exchangers are used according to the application. It is named for the humidifier because it is to preheat the fuel and water so that a reactor will convert some of the incoming fuel to hydrogen. Then, hot side fluid service is used the exhausted gas from the fuel cell and cold side fluid service is the fuel and water. The operation temperature range is about 25~500 Celsius Degree. This heat exchanger has the problems of heat transfer considering to multiphase fluid and phase changing. So it is necessary to analyze the heat transfer characteristics and to propose the reasonable design methodology for the humidifier. In this study, the thermal characteristic for the humidifier is estimated by using commercial tool of heat exchanger design and rating. And this study provides the testing methodology and presents the results for test facility of fabrication and for testing.

• Journal of the Korean Electrochemical Society
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• v.5 no.2
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• pp.62-67
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• 2002

The corrosion of the metallic cell components is blown to be one of the major reason f3r the performance degradation and subsequently the life-time limitation of the MCFC. To elucidate the corrosion phenomena, a corrosion study with the AISI-type 316L stainless steel, the most widely used separator material, in 621Li/38K carbonate eutectic melt was carried out. Corrosion phenomena in an MCFC were observed to differ from one location to another due to different environmental condition. The stability of passive film was found to be responsible fur the variations in corrosion phenomena. According to the potentiodynamic analysis, the passive film formed in anode-gas environment was less stable than in cathode-gas environment. The potentiostatic method combined with XRD analysis in addition to the cyclicvoltammetry was conducted to get an insight on variety corrosion reaction of AISI-type 316L stainless steel in a carbonate melt.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1322-1324
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• 2002

For developing a 100 kW MCFC power generation system, Several design parameters for a fuel cell stack and system analysis results by Cycle Tempo, a processing computer soft ware, were described. Approximately 170 cells are required to generate 100 kW at a current density of 125 mA/$cm^2$ with 6000 $cm^2$ cells. An overall heat balance was calculated to predict exit temperature. The 100 kW power is expected only under pressurized operation condition at 3 atm. Recycle of cathode gas by more than 50% is recommended to run the stack at 125 mA/$cm^2$ and 3 atm. Manifolds should be designed based on gas flow rates for the suggested operating condition. The fuel cell power generation system was designed conceptually with several choices of utilization of anode exhaust gas. Also system efficiency was calculated at various type of system and operation conditions.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.69-74
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• 1997

MCFC(Molten Carbonate Fuel Cell) Ni anode의 기계적 특성을 개선시키기 위해서 Ni-W복합재료를 기계적 합금법으로 제조하였다. 기계적 합금화한 분말을 XRD, SEM으로 관찰한 후 두께 1mm, 직경 8mm의 원반형으로 성형하였다. 소결은 120$0^{\circ}C$의 수소 분위기내에서 10시간 행하였다. 이렇게 제조한 시편의 절단된 면을 연마하여 SEM 및 EDX로 관찰하였으며 XRD로써 성분분석 하였다. 기계적 합금화 시간이 증가함에 따라 불충격에 의한 결정립 미세화가 이루어졌으며 80시간 기계적 합금시 재료의 규칙적인 결정이 파괴되어 비결정질화 되었다. 기계적합금으로 Ni 기지내에 균일하게 분포된 W은 분산강화효과를 통해 Ni anode의 기계적 특성을 개선시킬 것으로 기대된다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.87.2-87.2
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• 2010

The steady and dynamic process model for an internal reforming molten carbonate fuel cell power plant is discussed in this paper. The dominant thermal and chemical dynamic processes are modeled for the stack module and balance-of-plant, including cathode gas preparation, heat recovery, heat loss (Each heat loss amount for the stack and MBOP is obtained from real plant data) and fuel processing. Based on dynamic model and control demand, PID controllers are designed in the whole system. By applying these controllers we can obtain temperature balance of stack and control system depending on changing steam to carbon ratio, air feed amount, and transient condition.

• Journal of the Korean Ceramic Society
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• v.32 no.2
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• pp.197-208
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• 1995

${\gamma}$-LiAlO2 fibers for fiber reinforced molten carbonate fuel cell (MCFC) matrix have been produced from LiAlO2 complex polymeric sols using the sol-gel process. The stable and spinnable LiAlO2 sols could be synthesized by mixing LiNO3 alcohol solutions in aluminum complex polymeric sols prepared through the condensationpolymerization reaction of 1 more of aluminum tri-sec-butoxide with 0.55 mole of mixed chelates (mole ratio of acetylaceton/triethanolamine=0.25/0.3). It was found that the viscosity range for fiber-spinning should be higher than 30 poise. The defect-free flexible ${\gamma}$-LiAlO2 fibers with the average tensile strength of 350 MPa could be obtained when the spinned fibers were heat-treated to 120$0^{\circ}C$ on the specified heating schedule after dried at room temperature.