• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.463-466
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• 2006

직접 알콜 연료전지는 액체인 알콜을 직접 연료전지에 공급하여 연소시킴으로써 높은 효율을 갖는 휴대용전원으로 주목받는 장치이다. 직접 알콜 연료전지에 담지체로 사용되는 탄소 소재는 넓은 표면적과 우수한 전기전도도를 가지고 있다는 장점 있으나 금속 촉매와의 상호작용이 약하여 촉매 활성에 영향을 주지 못한다. 산화물을 담지체로 사용할 경우 이러한 금속-담지체 간의 상호작용으로 인한 촉매활성 증가 및 입자성장 억제의 효과를 기대할 수 있다. 본 연구에서는, 안티몬 도핑된 주석산화물 (Sb-doped SnO2 : ATO nanoparticle)을 직접 메탄올 연료전지용 담지체어 적용하였으며 합성 과정은 다음과 같다. SnC14 5H2O SbC13, NaOH, HCl 수용액 혼합물을 삼구 플라스크에 넣고 $100^{\circ}C$ 온도에서 환류(reflux) 시킨 후 세척 및 건조하여 Air 분위기에서 열처리하였다. 합성된 산화물 수용액에 폴리올 방법으로 합성된 백금 콜로이드를 담지하였으며, 세척과 건조를 통하여 산화물에 담지된 백금 촉매를 촉매를 합성하였다. 촉매의 구조분석을 위해 XRD, TEM을 사용하였으며, 전극촉매로서의 활성을 평가하기 위해 cyclic voltammetry을 평가하였다. 본 연구에서는 백금의 담지량에 따른 Costripping voltammetry특성과 메탄올 및 에탄올 산화 반응 특성에 대하여, 탄소를 담지체로 사용한 Pt/C 촉매와 비교 평가하였다. 알콜 산화반응 평가결과, 주석산화물에 담지한 촉매가 탄소를 담지체로 사용한 촉매보다 우수한 활성을 나타내었으며 활성증가는 메탄올에 비해 에탄올 산화 반응의 경우 크게 증가하였다. 막과 비교해 보았다. $ZrO_2$ 입자는 전도성이며 동시에 친수성을 나타내기 때문에 상용 막에 비하여 함수율 및 수소이온 전도도가 우수하게 나타났다. 복합막의 이러한 물성은 $100^{\circ}C$이상의 고온에서 전해질 막 내의 물 관리를 용이하게 한다. 단위 전지 운전 온도 $130^{\circ}C$, 상대습도 37%의 운전 조건에서도 상당히 우수한 전지 성능을 보임에 따라 고온/저가습 조건에서 상용 Nafion 112 막보다 우수한 막 특성을 나타냄을 확인하였다.소/배후방사능비는 각각 $2.18{\pm}0.03,\;2.56{\pm}0.11,\;3.08{\pm}0.18,\;3.77{\pm}0.17,\;4.70{\pm}0.45$ 그리고 $5.59{\pm}0.40$이었고, $^{67}Ga$-citrate의 경우 2시간, 24시간, 48시간에 $3.06{\pm}0.84,\;4.12{\pm}0.54\;4.55{\pm}0.74 $이었다. 결론 : Transferrin에 $^{99m}Tc$을 이용한 방사성표지가 성공적으로 이루어졌고, $^{99m}Tc$-transferrin의 표지효율은 8시간까지 95% 이상의 안정된 방사성표지효율을 보였다. $^{99m}Tc$-transferrin을 이용한 감염영상을 성공적으로 얻을 수 있었으며, $^{67}Ga$-citrate 영상과 비교하여 더 빠른 시간 안에 우수한 영상을 얻을 수 있었다. 그러므로 $^{99m}Tc$<

• Clean Technology
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• v.17 no.3
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• pp.215-224
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• 2011

It is an important issue to develop quality assessing system for biofuel for the purpose of accelerating the mass production of biofuel. It is particularly challenging to conduct testing method in the mass production of bioethanol while meeting quality specifications such as ASTM (American Society for Testing & Materials) D4806-10. In order to address this challenge, this paper proposes on-line spectroscopic quality assesment system based on Near Infrared spectrum and Partial Least Squares method in Chemometrics. As a result of testing a number of preprocessing methods and Partial Least Squares, it was found out that Savitzky-Golay method showed the best performance in terms of spectrum correction, noise reduction, and model maintenance. The proposed system allows us to assess multiple quality components continuously using spectroscopic facilities with the cheap cost. Since the value of R2 is more than 0.99, it is possible to replace the laboratory analysis.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.191-194
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• 2009

PtRu based and PtSn based ternary catalysts were prepared by a conventional impregnation method using NaBH4 as reducing agent. The alloy formation, crystalline size and chemical composition of the in-house catalysts were determined by XRD, TEM and EDX, respectively. The chemical compositions of in-house catalysts were quite similar to the nominal value and good alloy formations were also observed. Further, crystalline sizes of ternary catalysts were comparatively smaller than binary catalysts and were approximately 3.5 ~ 5.5 nm. The electrochemical measurements were carried out in the solution 1 M $H_2SO_4$ with 1 M $C_2H_5OH$ at room temperature. LSV results obtained that ternary catalysts were higher current densities and specific activities. Especially, in case of tungsten addition system, Pt5Sn4W/C have the highest specific activities values and was approximately 21.2 and 3.1 times higher than that of PtRu/C and PtSn/C electrocatalyst.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.44.2-44.2
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• 2011

고분자 전해질 연료전지는 다른 연료전지에 비해 작동온도가 낮고 전류밀도 및 출력밀도가 높으며 시동시간이 짧아서 다양한 분야에 응용이 가능할 것으로 기대된다. 그 중 양극판은 가격비와 중량비가 높아 부품 가격 및 중량을 낮출 경우 파급 효과가 높은 것으로 예상된다. 본 연구에서는 일반적으로 사용하고 있는 스테인리스강보다 가격이 저렴한 저탄소강을 모재로 이용하였다. 저탄소강은 자체로 내식성을 가지지 못하므로, 최근에 차세대 신소재로 각광을 받고 있는 그라핀(graphene)을 전기분무(electro spray coating)법으로 코팅하여 저탄소강의 내식성을 향상시키고자 하였다. 그라핀은 에탄올을 용매로 사용하여 분산하였으며, 분산제로 소량의 다이페닐다이에톡시실란(diphenyldiethoxysilane)을 첨가하여 코팅용액을 제작하였다. 코팅공정은 5~15 kV의 전압을 가하여 1시간동안 코팅을 진행하였으며, 그라핀-저탄소강의 미세구조를 주사전자현미경과 광학현미경을 통하여 관찰하였다. 또한 X-선 회절분석법을 이용하여 그라핀의 결정구조를 분석하였다. 한편 스택의 내부와 유사한 산화성 분위기를 모사하기 위해 $80^{\circ}C$의 0.1N $H_2SO_4$+2ppm $F^-$ 용액에서 내식성 실험을 수행하였고 면간접촉저항을 측정하였다. 그라핀이 코팅된 저탄소강 시편은 고분자 전해질 연료전지 양극판의 요구조건을 만족하였으며, 연료전지 양극판으로서의 사용가능성을 확인하였다.

• Journal of the Korean Electrochemical Society
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• v.4 no.2
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• pp.65-69
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• 2001

The potential change, and the crossover of alcohol in a liquid-feed solid polymer electrolyte fuel cell operating at atmosphere and room temperature was investigated. Alcohol crossover was generated from all the alcohol by using the fuel. The single-cell property of direct methanol fuel cell was higher than that of other alcohol species as $31mW/cm^2$ at 0.23 V at 4.5M of methanol.

• Journal of Hydrogen and New Energy
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• v.22 no.2
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• pp.257-264
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• 2011

This study discribes performance of DEFC (Direct Ethanol Fuel Cell) utilized bio-ethanol based on fruit wastes. To produce the bio-ethanol, fruit wastes were treated at temperature $120^{\circ}C$ and 90minutes in acid pre-treatment. After pre-treatment was done, alcohol fermentation process was running. Initial alcohol concentration was 5%. Using the multi coloumn distillation system, more than 95% ethanol was distilled and each component of bio-ethanol was analyzed. In DEFC performance test, it was revealed that cell performance was much higher than that of ethanol. Comparing ethanol with mixed fuel (bio-ethanol (10%) + ethanol (90%)), the performance of ethanol was higher than that of mixed fuel. Even though the bio-ethanol from the fruit wastes is corresponded with transport ethanol standards, it thought that organic matter in bio-ethanol could be negative effect on fuel cell.

• Journal of the Korean Electrochemical Society
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• v.11 no.2
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• pp.109-114
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• 2008

Though ethanol can theoretically generate 12 electrons during oxidation to carbon dioxide, the complete oxidation of ethanol is hard to achieve due to the strong bond between the two carbons in its molecular structure. Therefore, development of high activity catalyst for ethanol oxidation is necessary for the commercialization of direct ethanol fuel cell. In this study, some binary and ternary electrocatalysts of PtSn/C and PtSnAu/C have been synthesized and characterized. The catalysts were fabricated with modified polyol method with the amounts of 20 wt%, where the Pt : Sn ratios in the PtSn/C were 1 : 0, 4 : 1, 3 : 1, 2 : 1, 1.5 : 1, 1 : 1, 1 : 1.5 and Pt:Sn:Au ratios in the PtSnAu/C were 5 : 5 : 0, 5 : 4 : 1, 5 : 3 : 2, 5 : 2 : 3. From the XRD and TEM analysis results, the catalysts were found to have face centered cubic structure with particle size of around $1.9{\sim}2.4\;nm$. The activity in the ethanol oxidation was examined with cyclic voltammetry and the results indicated that PtSn(1.5 : 1)/C and PtSnAu(5 : 2 : 3)/C had the highest activity in each catalyst system. Further tests with single cell were performed with those catalysts. It was found that PtSn/C(1.5 : 1) exhibited the best performance while the long term stability of PtSnAu/C(5 : 2 : 3) is better than PtSn/C(1.5 : 1).

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.94-101
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• 2001

In this paper, the combustion improvement effects of alcohol-diesel oil blend fuel were investigated in a visualization engine. As a result of experiment, it was found out that the combustion chamber of deep dish type and re-entrant type at the same operation condition. However, when the con-tent of alcohol exceeded 10% of total fuel delivery, the combustion of alcohol-diesel oil blend fuel was worse than that of diesel oil. The maximum blend quantity of ethanol which is not ignited in the re-entrant type combustion chamber was estimated at approximately 40% of total fuel delivery. So, it is necessary to blend appropriate quantity of a volatility fuel such as alcohol in order to improve combustion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.14-20
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• 2012

Performance and anti-corrosion of cold forged fuel pumps and die-casting fuel pumps have been tested in this study. Ethanol with 10 ppm of acetic acid is applied for the anti-corrosion test for 250 hours. Performance test result shows that the pumping efficiency of the cold forged fuel pump is equivalent to that of the die-casting fuel pump. The cold forged lower housing has better quality against corrosiveness and finer metallic structure than the die-casting lower housing does.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.82-88
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• 2011

Lean combustion and exhaust emission characteristics in a ethanol fueled spark-ignited engine according to ethanol-gasoline fuel blending ratio were investigated. The test engine was $1591cm^3$ and 10.5 of compression ratio SI engine with 4 cylinders. In addition, lambda sensor system was connected with universal ECU to control the lambda value which is varied from 1.0 to 1.5. The engine performance and lean combustion characteristics such as brake torque, cylinder pressure and rate of heat release were investigated according to ethanol-gasoline fuel blending ratio. Furthermore, the exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), nitrogen oxides ($NO_x$) and carbon dioxide ($CO_2$) were measured by emission analyzers. The results showed that the brake torque, cylinder pressure and the stability of engine operation were increased as ethanol blending ratio is increased. Brake specific fuel consumption (BSFC) was increased in higher ethanol blending ratio while brake specific energy consumption (BSEC) was decreased in higher ethanol blending ratio. The exhaust emissions were decreased as ethanol blending ratio is increased under overall experimental conditions, however, some specific exhaust emission characteristics were mainly influenced by lambda value and ethanol-gasoline fuel blending ratio.