• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.230.2-230.2
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• 2010

천연가스 수증기 개질 반응에 사용되는 펠릿 촉매의 단점인 열 및 물질 전달 제한, 낮은 effectiveness factor, 압력강화와 channeling 등의 문제점을 해결 하고자 모노리스 형태의 금속 구조체 촉매를 본 연구에 적용 하였다. Fecralloy 재질의 금속 구조체에 Ni 촉매를 워시코팅 (wash coating) 하여 제조 하였으며, 이를 천연가스 수증기 개질 반응에 적용하여 수소를 생산하였다. 실험 조건으로는 S/C ratio를 3으로 고정하여 온도를 $600^{\circ}C{\sim}800^{\circ}C$로 변화 시켰으며, GHSV $3000{\sim}30000h^{-1}$에서 진행 되었다. 구조체 촉매 코팅에 사용된 Ni 촉매의 BET, TPR, H2-chemisorption, SEM, EDS의 특성분석을 수행 하였다. 온도별 테스트에서 모노리스 형태의 금속 구조체 촉매가 펠릿 형태의 촉매에 비해 우수한 열전달 효과로 인해 낮은 퍼니스 온도와 높은 반응 활성을 나타내었으며, GHSV 변화에 따른 성능평가 결과도 15wt% $Ni/MgAl_2O_4$펠릿 촉매와 비교하여 금속 구조체 촉매가 높은 활성을 보였다.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.75-78
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• 2007

천연가스의 수증기 및 이산화탄소 복합 개질은 탄화수소화합물과 이산화탄소를 원료로 사용하여 수소를 생산하는 공정으로, 온실가스로 지목되고 있는 주요 화합물을 수소와 일산화탄소 혼합 가스로 전환시켜 합성 반응 또는 연료전지에 사용할 수 있도록 해준다. 본 연구에서는 $MgAl_2O_4$를 지지체로 하는 니켈계 촉매를 제조하여 수증기 및 이산화탄소 복합 개질 반응에 사용하였으며, 기존의 수증기 개질촉매 적용 시 문제가 되었던 탄소 침적에 의한 촉매 비활성화를 피할 수 있었다. 개발된 촉매 레시피를 바탕으로 펠릿 촉매를 제조하여 0.1 bpd규모의 Fischer-Tropsch 합성 반응에 적용 가능한 튜브형 반응기에 적용하여 수증기 및 이산화탄소 복합 개질 반응을 실시하였으며, 반응기의 온도 구배, 가스 조성 변화를 관찰하였다. 반응 조건에 따른 촉매 및 반응기의 성능 최적화를 실시하여 최적 촉매 및 반응기 성능을 모색하고자 하였다.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.463-467
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• 2005

To reduce salt content in Korean traditional kochujang, horseradish powder (1.2%, w/w) was added to kochujang with 4-10% salt, and its microbial characteristics, enzyme activities, and gas formation in kochujang were evaluated during fermentation far 120 days at $25^{\circ}C$. All treatments of kochujang had no effects on total viable bacterial numbers, which kept constant level, during fermentation (7.32-8.765 log CFU/g). Yeast numbers did not change under all treatments up to 90 days of fermentation, then decreased thereafter, ${\alpha}$-Amylase and ${\beta}$-amylase, and neutral- and acid-pretense activities of kochujang added with horseradish powder were higher than those of control group. ${\beta}$-Amylase activity of kochujang increased in proportion to salt concentration. Total accumulative volume of gas produced during fermentation of kochujang without horseradish powder was 5,892 mL/pack then decreased to 121-347mL/pack with low-salted kochujang (salt 4%, 6%) added with horseradish powder, Major gas produced was $CO_{2}(74-80%)$. Results indicate salt contents of kochujang could be lowered up to 6% by addition of horseradish powder without gas formation and quality alteration.

• Journal of Environmental Health Sciences
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• v.17 no.2
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• pp.114-120
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• 1991

대기부유입자상물질이나 diesel 배출가스중에 함유하여, 주요한 direct-acting mutagen의 하나로 작용하는 1-nitropyrene, 1,3-, 1,6- 및 1,8-dinitropyrene을 합성하고, 고속액체 chromatography로 분리정제하여, Salmonella typhimurium TA 98, S9mix 비첨가의 계에서 돌연변이원성을 측정한 결과, 1-nitropyrene에 비하여, dinitropyrene은 강력한 돌연변이 원성을 나타내었고, 그 중에서도 1,8-dinitropyrene은 733,000 revertants/$\mu$g으로 최고의 돌연변이원 활성을 나타내었다.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.314-319
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• 2013

In this study, nitrogen doped $TiO_2$ ($N-TiO_2$) coated on an activated carbon pellet (ACP) was prepared using sol-gel and the solid state heat treatment of urea to improve the removal property of volatile organic compounds (VOCs). To explore the visible light photocatalytic activity of the ACP under the light emitting diods (LED), the removal property of benzene gas was characterized by gas chromatography. The SEM and BET results show that the increment of titanium tetra isopropoxide contents leads to the increased $TiO_2$ coating amount of ACP surface and decreased specific surface area. From the results of benzene gas removal, the breakthrough time of ACP10 increased about 2 times compared to that of the ACP. The improved performance was attributed to the $N-TiO_2$ coating on ACP surface, which could be more effective to remove benzene gas under the condition of LED lamp.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.963-968
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• 1999

The global environmental problems have been caused by the release of CFCs. Therefore, methods for safe destruction of recoverd CFCs will be eventually needed. The objective of this study was to develop and test a catalyst operating at a mild condition for the decomposition of CFC-113. In this work, catalytic oxidative decomposition of CFC-113 was carried out over aerosol $TiO_2/SiO_2(ATS)$ catalysts prepared by the sol-gel method. All ATS catalysts(Ti/Si mol ratio=1, 2, 2.33, 4) showed high initial activity. However, the deactivation of ATS catalysts was found that more remarkable due to an attack of fluorine and the destruction of ATS structure(Si-F reaction) from analyses of SEM-EDX, XRD than $TiO_2/SiO_2(ATS)$ catalyst prepared by the precipitation method. ATS catalysts prepared by more acidic prehydrolysis condition were found to have still more activity and longer life-time by increasing of acidity. The activity of ATS catalyst also depend on the content of $TiO_2$. There was reason that the acidity of the ATS catalyst was increased with the increased content of $TiO_2$ from 50 to 80 mol %. Solid superacid catalyst ($ATX/SO_4{^{2-}}$) modified with $H_2SO_4$ solution was prepared for high activity and lower deactivation. The reaction of $ATS/SO_4{^{2-}}$ catalyst also exhibited even higher activity and lower deactivation than the original ATS catalyst. It is suggested that the addition of the sulphate species clearly inhibit the deactivation.

• Journal of Energy Engineering
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• v.6 no.1
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• pp.34-40
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• 1997

This study aims to investigate the application possibility on natural gas in relation to the catalytic combustion of methane on Pd/cordierite catalyst which is currently used as an automobile converter catalyst. The surface area of the catalyst tested was determined to be about 18.7㎡/g and to keep stable condition in structure at mid-high temperatures. The activation energy for methane combustion reaction was estimated to be 19.2 kcal/mol and a hysterisis on the catalyst activity was observed in terms of the catalyst deactivation as the reaction temperature was varied for the methane combustion. On Pd/cordierite catalyst, The characteristics of methane combustion were studied as functions of space velocity and air/fuel ratios below 700$^{\circ}C$.

• Fire Science and Engineering
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• v.19 no.2 s.58
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• pp.69-74
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• 2005

A study of the utilization of inert gas generator(IGG) that generates a large amount of inert gas for the fire extinguishing equipment was performed. In this study, the fire extinction performance of gas generated from a 1GG which is implemented to a gas turbine was investigated. A simulated mixture gas of which composition is the same as that of the gas generated from ICG was used in all experiments. First, the extinction concentration was measured using a cup burner method. The extinction design concentration and the volume of extinction space was calculated by applying the obtained extinction concentration to a method recommended by NFPA 2001. In practical respects, the fire extinction performance of IGG-generated gas was confirmed through the fire suppression experiment within a $2m\times2m\times2m$ room.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.265-270
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• 2004

To select a promising technologies for removal of odorous gases emitted from a wastewater pump station, four methods such as activated carbon (A/C) adsorption, chemical absorption (acid and alkali scrubber), and two biofilters (polyurethane (PU) and worm cast) were investigated. The average odor removal efficiencies in the PU biofilter and A/C column was over 98%, but in a worm cast biofilter and chemical absorption were below 60-80%. The removal efficiency of PU biofilter was very stable (about 98-99%) in the range of retention times of 4-36s, and a maximum elimination capacity was $1.6${\times}$10^{ 7}$ $OUm^{-3}$$h^{-1}$ Deodorization costs for an activated carbon adsorption and a biofiltration method were investigated. With increasing odor intensity, the operating cost of the A/C column increased linearly, but the operating cost of the biofilteration increased slightly. The capital cost in a biofilter is about two times higher than that in an A/C column, but the operating cost is very lower than that of in A/C column. In conclusion, the biofiltration was evaluated one of the most promising technologies to control odor in a wastewater pump station.

• Proceedings of the KSMRM Conference
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• 1999.11a
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• pp.19-25
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• 1999

허파에 대한 수소 자기공명영상은 현재까지 거의 불가능한 것으로 알려져 있다. 허파의 조직과 비어있는 공간 사이의 심한 자화율(susceptibility) 차이로 인해서 영상왜곡 현상이 유발되어 그릇된 영상정보를 만들기 때문이다. 본 강좌에서는 이러한 문제를 해결할 수 있는 레이저 광펌핑 방법으로 초편극화된 비활성기체를 이용한 자기공명연구를 소개한다. 일반적인 자기공명 신호와 쳐편극화된 비활성기체를 이용한 자기공명 연구를 소개한다. 일반적인 자기공명 신호와 초편극화 기체를 이용한 신호의 차이와 물리적인 원리를 고찰할 것이다 . 비활성기체가 초편극화 되었을 때, 일반적인 자기공명의 경우에 (자기장: 1 Tesla, 온도는 $30^{\circ}C$의 열평형상태) 비해서 약 $10^{5}$ 정도의 magnetizaion 향상을 기대할 수 있으며, 기체상태라는 점이 감안된다 해도 의미 있는 자기공명신호를 획득할 수 있다. 비활성기체를 초편exchange 방법을 통하여 간접적으로 가스를 편극화 시키는 두 가지 방법이 있다. 이들의 기본적인 원리와 두 방법의 장단점 등을 알아 볼 것이다. 더불어, 초편극화 정도가 외부자기장의 세기 차이에 의한 영향을 받지 않는 다는 특성을 이용하는 경우, 비용을 최소화 하면서 고해상도의 영상을 얻을 수 있으며, 이동성이 용이한 낮은 자기고명진단기가 가능한데 이에 대한 소개를 할 것이다. 그리고, 초편극화가스를 이용한 자기공명영상 연구의 현재 동향 및 미래에 대해서 논의한다.