• Journal of Hydrogen and New Energy
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• v.20 no.5
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• pp.439-446
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• 2009

This paper investigates the dehydration and RDF (Refuse Derived Fuel) production of organic wastes, livestock manure and sewerage sludge with pressurized hydrothermal treatment process. The renewable technology for the organic wastes must involve short treatment time required, reusable energy source, anti-odor and viruses, low cost for the treatment, and well-fertilization. The pressurized hydrothermal treatment process promotes to evaporate moisture in the waste after being shortly treated in a reactor, which uses steam and heat supplied by an external boiler. By the pressurized steam, the cell walls of the waste break and effectively release the internal moisture. Then, the dried waste can be mixed with waste vinyls to produce RDF with a higher heating value as high as 6,700 kcal/kg.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.33-35
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• 2020

해양 및 대기 오염 방지를 위한 친환경선박에 대한 관심이 고조되고 있고 특히 LNG를 연료로 하는 LNG 연료추진선이 확대되고 있다. 그리고 국내에서도 LNG Bunkering 선박 건조에 지속적으로 추진되고 있다. LNG Bunkering의 안전한 운용을 위해서는 여러 위험요소를 분석해야한다. 그 중에도 LNG Bunkering 작업 중 주변 선박 통항에 따른 안전한 이격거리의 확보 또한 중요한 사항이지만 이에 대한 연구는 미진한 형태이다. 이에 안전한 이격거리에 대해서 외국 및 국내규정을 검토하였으나 명확한 규정이 없어 이에 대한 분석을 통한 안전하고, 경제적인 이격거리에 대한 연구가 필요하다. 안전한 이격거리에 대해 분석하기 위한 우선적으로 안전한 이격거리에 영향을 미칠 요소에 대해 검토한다.

• Resources Recycling
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• v.19 no.6
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• pp.43-50
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• 2010

The crisis of energy gives rise to the growing concerns over continuing uncertainty in the energy market. Under these circumstances, there are also increasing interests on coals. In particular, Low Rank Coal (LRC) is receiving gradual attentions from green industry. But due to is high moisture content range from 30 - 60%, drying process has to be preceded before being utilized as power plant. In this study drying kinetics of LRC is induced by using a fixed-bed reactor. The drying kinetics was evaluated in from of the particle size, the inlet gas temperature, the drying time, the gas velocity, and the LID ratio. The consideration of the reynold's number was taken for correction of gas velocity, particle size and LID was taken for correction of reactor diameter, packing height of coal. As being seen as characteristic of drying coal, it can be found that fixed-bed reactor can contributed to active drying of free water. In this sense, it could be considered that phase boundary reaction is appropriate mechanism.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.273-273
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• 2009

고체산화물 연료전지 (Solid Oxide Fuel Cell, 이하 SOFC)는 제조형태에 따라 크게 평판형과 원통형으로 구분할 수 있다. 단위면적당 출력 효율이 높은 평판형의 장점과 원통형의 밀봉이 용이한 장점을 동시에 가지는 평관형 형태로 지지체를 제작하였으며, 셀의 배치를 평면상 직렬로 연결하는 다전지식으로 구성함으로 전극의 길이나, 셀 간격을 기존 평판형이나 원통형에 비해 대폭 감소시켜 단위면적당 전압 및 출력효율을 높이고자 하였다. Segmented 평관형 지지체의 소재로는 연료전지의 성능 특성에 관여하지 않으며 열사이클 저항성과 기계적 강도가 우수한 spinel구조를 가지는 $MgAl_2O_4$를 선정하였다. 연료가스의 원활한 공급이 가능하도록 carbon을 기공 전구체로 사용하여 압출성형하였으며 건조과정에서 crack이 생기지 않는 공정을 확립한 후 $1400^{\circ}C$ 에서 소결하였다. 제조된 지지체는 수은침투법과 3점 굽힘 강도법으로 기공율과 기계적 강도를 각각 측정하였다. Anode를 스크린 프린팅법으로 지지체 위에 적층한 후 미세구조를 확인하였고 이를 바탕으로 다공성이며 기계적 강도를 가지고 음극과의 반응이 없는 우수한 지지체를 제조할 수 있었다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.278-281
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• 2009

The performance of aluminum bipolar plates was evaluated for the lightweight fuel cell system as a power source for a small reconnaissance UAV. Higher performance per weight was obtained from aluminum bipolar plates than the graphite bipolar plates. To check the influence of operating temperature, the performance of a single cell using aluminum bipolar plates was evaluated at 40 / 50 / $60^{\circ}C$. When dry hydrogen and air were used, the finest performance was obtained at $40^{\circ}C$, a lower operating temperature compared with usual operating temperatures.

• Membrane Journal
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• v.25 no.2
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• pp.171-179
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• 2015

Perfluorinated sulfonic acid ionomers (PFSAs) have been widely as solid electrolyte materials for polymer electrolyte membrane fuel cells, since they exhibit excellent chemical durability under their harsh application conditions as well as good proton conductivity. Even PFSA materials, however, suffer from physical failures associated with repeated membrane swelling and deswelling, resulting in fairly reduced electrochemical lifetime. In this study, pore-filling membranes are prepared by impregnating a Nafion ionomer into the pore of a porous PTFE support film and their fundamental characteristics are evaluated. The developed pore-filling membranes exhibit extremely high proton conductivity of about $0.5S\;cm^{-1}@90^{\circ}C$ in liquid water.

• Journal of the Korean Electrochemical Society
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• v.8 no.4
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• pp.149-154
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• 2005

Fuel cell performance evaluation logic was developed using G-language (LabVIEW) to measure performance stability. Degree of stability and reliability of performance data were improved with averaged value and standard deviation method. Water injection system was introduced and the performance using this method was comparable to that of conventional humidification method. Water injection system has advantage of lowering operation energy consumption, reducing the number of parts needed in humidification, therefore increasing efficiency of fuel cell system. Fuel cell performance was decreased in case of low temperature operation such as sub freezing condition. Air purge method was tested to reduce the water content in cell fixture before sub freezing condition. The performance degradation due to low temperature operation was minimized by air purge method in medium size cell fixture ($25cm^2$) case.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.297-298
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• 2007

본 논문은 가열된 폐식용유를 이용하여 음식물류폐기물에 포함된 수분을 증발시키고 고형성분을 익혀 사료, 퇴비 및 연료화 할 수 있는 장치를 소개한다. $200^{\circ}C$의 폐식용유에서 l분 이내에 완전 건조 처리되며 멸균을 시킬 수 있어 효과적이다. 열원은 소각로 열을 재활용할 경우 경제적이다. 탈리액의 해양투기가 금지될 경우 탈리액을 획기적으로 줄이는 대안이라 여겨진다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.255-256
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• 2000

휘발성 유기화합물(Volatile Organic Compounds : VOCs)은 각종 산업체에서 많이 사용되고 있는 용매와 화학 및 제약공장 플라스틱의 건조공정에서 배출되는 유기가스 등까지 매우 다양하며, 저비점 액체연료, 파라핀, 올레핀, 방향족 화합물등 우리 생활주변에서 흔하게 사용되는 탄화수소류들이 거의 VOCs이다. 이러한 VOCs를 제어하기 위하여 폭넓은 제어기술의 연구 및 개발이 진행되고 있다. (중략)

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.639-647
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• 2022

The use of flames is essential in cutting, bending, and welding steel during a ship's construction process. While acetylene fuel is commonly used in steel cutting and the manufacturing process in shipyards, the use of propane as an alternative fuel has recently been increasing, due to the lower risk of explosion and propane's relatively low calorific value. However, propane fuel has a relatively slow processing speed and high slag generation frequency, thereby resulting in poor quality. Propylene is another alternative fuel, which has an excellent calorific value. It is expected to gain wider use because of its potential to improve the quality, productivity, and efficiency of steel processing. In this study, the combustion characteristics of propane and propylene fuel during steel plate processing were analyzed and compared. The reduction of greenhouse gases and other harmful gases when using propylene flame was experimentally verified by analyzing the gases emitted during the process. Heat distribution and tensile tests were also performed to investigate the effects of heat input, according to processing fuel used, on the mechanical strength of the marine steel. The results showed that when propylene was used, the temperature was more evenly distributed than when propane fuel was used. Moreover, the mechanical tests showed that when using propylene, there was no decrease in tensile strength, but the strain showed a tendency to decrease. Based on the study results, it is recommended that propylene be used in steel processing and the cutting process in actual shipyards in the future. Additionally, more analysis and supplementary research should be conducted on problems that may occur.