• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.213-216
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• 2009

WGS(Water Gas Shift)반응은 일산화탄소(CO)를 이산화탄소($CO_2$)로 전환하는 반응으로 일체형 수소생산시스템의 실현을 위한 고순도 수소생산에 있어서 중요한 단계이다. WGS 반응은 열역학적 평형을 고려하여 고온전이반응(HTS: High Temperature Shift)과 저온전이반응(LTS: Low Temperature Shift) 두 단계 반응으로 진행된다. 두 단계 공정의 통합을 위해 낮은 온도에서 높은 활성을 갖는 WGS 반응용 촉매 개발이 필요하다. 최근 낮은 온도에서 높은 활성을 갖는 귀금속 촉매에 다양한 담체를 적용시킨 연구가 활발히 진행되고 있다. 선행 연구 결과, Ce-$ZrO_2$ 구조는 Ce/Zr 비에 따라 다양한 특성 변화를 관찰하였다. 따라서 낮은 온도에서 높은 활성을 갖는 WGS 반응용 촉매 제조를 위해 환원성 담체인 $CeZrO_2$에 Pt 을 담지시켜 성능을 평가하였다. 제조된 모든 담체는 공침법(Co-precipitation)으로 제조 하였으며 $500^{\circ}C$에서 6시간 소성하였다. 제조된 담체에 백금(Pt)을 함침법(Incipient Wetness Impregnate)으로 담지시켰다. 특성분석은 BET를 이용하여 표면적을 측정하였다. 촉매 반응 실험조건은 $200^{\circ}C{\sim}400^{\circ}C$ 온도범위에서 기체공간속도(GHSV: Gas Hourly Space Velocity) 45,000 ml/$h{\cdot}g-cat$ 으로 혼합가스($H_2$:60%, $N_2$:20%,$CH_4$:1%,CO:9%,$CO_2$:10%)를 흘려 반응 후 배출되는 가스를 Micro-Gas Chromatography 를 이용하여 측정하였다.

• 한국추진공학회지
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• 제23권2호
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• pp.46-52
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• 2019

케로신 연료의 침탄 특성에 대한 온도의 영향을 분석한 실험이 수행되었다. 케로신을 각각 600 K, 700 K, 800 K으로 가열한 후, 냉각시킨 시료를 채취하였다. 사용된 구리관은 온도조건에 따라 새로이 교체했다. 기체 크로마토그래피-질량분석과 에너지분산형 X선 분광기가 장착된 주사전자현미경을 통해 액체 시료와 구리 시편의 침탄 특성을 각각 분석하였다. 그 결과, 비교적 고온(800 K)으로 가열된 구리 시편의 내부표면에서 연료의 침탄으로 인해 침전물이 발생한 것을 확인하였다.

• Macromolecular Research
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• 제10권2호
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• pp.97-102
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• 2002

The mixtures of non-conjugated dienes, 4-methyl-1,4-hexadiene and 5-methyl-1,4-hexadiene (MHD), were successfully synthesized by the reaction of isoprene with ethylene using Fe(III)-based catalyst in toluene. The conversion was over 96 mol% on the basis of the initial amount of isoprene used. The production yield for MHD was nearly 50 mol%, the other was polyisoprene. The mixtures were successfully copolymerized with ethylene by using zirconium-based metallocenes. The products were characterized by the combinations of gas chromatography, high temperature gel permeation chromatography, $^1$H NMR, $^{13}$ C NMR, high temperature $^1$H NMR, UV/visible spectroscopy, and differential scanning calorimetry. It was found that 5-methyl-1,4-hexadiene was active enough to be incorporated into the copolymer chain but the corresponding isomeric material,4-methyl-1,4-hexadiene, was inactive in metallocene-catalyzed copolymerizations. Specifically, in the zirconocene-catalyzed copolymerizations of ethylene with MHD, ansa-structure catalysts seem to be more efficient than non-bridged type zirconocene. The degree of incorporation of MHD in the resulting copolymers was able to be controlled by the amount of non-conjugated dienes used initially.

• 전기학회논문지
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• 제59권5호
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• pp.912-917
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• 2010

It was known that oil-filled transformer's life depended on insulating paper which was applied to transformers for insulating of transformer. Therefore when paper was aged, its electrical, mechanical and chemical characteristics were changed. Especially if operating temperature was high, paper was quickly damaged. As cellulose paper which was mainly used for solid insulation of transformers was degraded, the cellulose polymer chains broke down into shorter lengths and gases such as CO, $CO_2$, $CH_4$, $C_2H_4$ and so on were produced from paper. Also by-product known as furan compounds were producted from paper and it were dissolved within insulating oil. In this paper accelerating aging cell was aged during 60 hours at 100, 150, 180 and $200^{\circ}C$, respectively, so evaluating the chemical characteristics of cellulose paper by thermal. An it were performed analysis such as tensile strength(TS), dissolved gas analysis(DGA) and high performance liquid chromatography(HPLC). Also for analyzing of correlation between insulating degradation characteristics, it was performed linear regression method as statistical treatment.

• 한국분무공학회지
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• 제28권3호
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• pp.143-149
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• 2023

Amidst the drive towards carbon neutrality, interest in renewable synthetic e-fuels is rising rapidly. These fuels, generated through the synthesis of atmospheric carbon and green hydrogen, offer a sustainable solution, showing advantages like high energy density and compatibility with existing infrastructure. The physical properties of e-fuels can be different from those of conventional gasoline based on manufacturing methods, which requires investigations into how the physical properties of e-fuels affect the fuel injection characteristics. This study performs a comparative analysis between conventional and Fischer-Tropsch (F-T) synthetic gasoline (e-gasoline) across various fuel temperatures, including the cold start condition. The fuel properties of F-T synthetic and conventional gasoline are analyzed using a gas chromatography-mass spectrometry technique and the injection rates are measured using a Bosch-tube injection rate meter. The F-T synthetic gasoline exhibited higher density and kinematic viscosity, but lower vapor pressure compared to the conventional gasoline. Both fuels showed an increase in injection rate as the fuel temperature decreased. The F-T synthetic gasoline showed higher injection rates compared to conventional gasoline regardless of the fuel temperature.

• 한국식품과학회지
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• 제47권2호
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• pp.176-183
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• 2015

고온반응기로 제조한 구운 불고기 반응향의 향미특성을 확인하기 위하여 휘발성 성분 및 향 활성 화합물을 동정하고 반응온도에 따른 향 활성 화합물의 변화를 확인하기 위하여 수증기증류 및 용매 동시추출법(SDE)을 이용하여 휘발성 향기성분을 추출하고, gas chromatography-mass spectrometry-olfactometry (GC-MS-O)를 통하여 비교 분석하였다. 고온반응기로 제조한 구운 불고기 반응향에서는 105종의 휘발성 성분이 동정되었으며, 이 중 furfural이 가장 높은 함량을 나타내었으며, 5-methyl furfural, phenylacetaldehyde 및 nonanal 등이 구운 불고기 반응향에 중요한 휘발성 성분으로 확인되었다. 또한 GC-MS-O를 통해 향 활성 성분을 분석한 결과 33종이 동정되었으며, 2,3-butanedione과 furfural 이 중요한 향 활성 화합물로 밝혀졌다. Hexanal, octanal, nonanal, undecanal, phenylacetaldehyde, 5-methyl furfural, 2,6-dimethyl pyrazine 및 dimethyl trisulfide도 구운 불고기 반응향의 향미특성에 중요한 역할을 하는 향 활성 성분으로 확인되었다. 반응온도에 따른 향 활성성분을 비교분석한 결과, 반응온도가 증가할수록 향 활성 성분도 증가하였으나, sulfide 화합물은 반응온도가 증가함에 따라 감소하였다.

• 한국식품조리과학회지
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• 제5권1호
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• pp.69-74
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• 1989

참치기름담금통조림과 굴, 홍합훈제기름담금통조림을 구입하여 Glass Capillary Gas Chromatography (Hewlett Packard, 5880 A)로 분석한 trans 지방산 함량과 산가, 과산화물가, 요오드가, 검화가 측정으로 관찰된 이화학적 성질의 변화는 다음과 같다. 1. 면실유가 주입된 참치, 굴, 홍합통조림에서 검출된 trans지방산의 대부분은 t,c-18:2이며 대두유가주입된 참치통조림에서 검출된 trans 지방산은 t,c-18:2 뿐만 아니라 c,c,t-18:3과 t,t,c-18:3도 소량 존재하였다. 2. Trans 지방산의 총평균 함량은 대두유가 주입된 참치통조림에서 2.26%로 가장 높았다. 또한 참치통조림의 경우 주입된 면실유나 대두유 모두 유통기간 긴 것에서 총 trans지방산 함량이 다소 더 높은 값을 보인 반면, 굴, 홍합통조림에서는 총 trans지방산 함량도 낮으면서 유통기간 중 변화도 거의 없는 것으로 나타났다. 3. 통조림에 주입된 유지의 유통기 간 중 산패도는 1년 내외의 기간에서는 산가가 0.5∼2.0 정도, 과산화물가는 0.6∼3.5 meq/kg oil 정도로 나타나 안정된 상태를 유지하고 있는 것으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.1951-1955
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• 2014

Catalytic pyrolysis of Geodae-Uksae 1, a kind of miscanthus found in Korea, was carried out over mesoporous MCM-48 catalysts. For rapid product analysis and catalyst evaluation, pyrolysis-gas chromatography/mass spectrometry was used. X-ray diffraction, nitrogen sorption, pyridine adsorbed Fourier transform infrared, and NH3 temperature programmed desorption were utilized to analyze the properties of the catalysts. Compared to non-catalytic reaction, catalytic upgrading over mesoporous Al-MCM-48 catalysts produced a higher-quality bio-oil with a high stability and low oxygen content. Al-MCM-48 exhibited higher deoxygenation ability than Si-MCM-48 due to its higher acidity.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.405-408
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• 2008

From the previous researches about flow characteristic of micro-nozzle, we found that viscosity and back pressure induced heavy losses in micro nozzle. To overcome thess losses, we began to study new conceptual micro propulsion system that is thermal transpiration based micro propulsion system. It has no moving parts and can pump the gaseous propellant by temperature gradient only (cold to hot). Most of previous research on thermal transpiration is in its early stage and mainly studied for application to small vacuum facility or gas chromatography in ambient condition using nanoporous material like aerogel. In this study, we focus on basic research of propulsion system based on thermal transpiration using polyimide material in vacuum conditions.

• 대한기계학회논문집B
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• 제31권2호
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• pp.202-207
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• 2007

In order to understand the phenomena of combustion instability, an experimental study was conducted at the moderate pressure and ambient temperature conditions. The flame behavior and the pressure fluctuations were measured in a dump combustor. Various types of combustion modes occurred in accordance with the equivalence ratio and the fuel supplying conditions. The fluctuation of pressure, heat release and equivalence ratio were measured by piezoelectric pressure sensor, high speed Intensified Charge Coupled Device (HICCD) camera and gas chromatography respectively. Two representative modes were self-excited pressure oscillations at the resonance of combustion chamber (200Hz) and instabilities related to the modulated fuel flow rate through the fuel holes (10Hz). It is found that, especially in an unchoked fuel flow condition, the modulation of the fuel flow rate affects the characteristics of flame behavior and pressure fluctuations in a lean premixed flame.