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티타니아에 담지된 귀금속촉매의 H<sub>2</sub>O-H<sub>2</sub> 전처리에 따른 휘발성유기화합물 산화에 미치는 영향
김문찬,고선환,Kim, Moon-Chan,Ko, Sun-Hwan 한국공업화학회 2007 공업화학 Vol.18 No.6
연구에서는 $TiO_2$ 담체에 귀금속(Pd, Ru, Ir)을 담지시켜 촉매를 제조하였다. 금속분산의 향상을 위해 $H_2O-H_2$ 전처리 기술이 이용되었고, 반응물로서 xylene, toluene 그리고 MEK를 사용하였다. 단일금속과 합금금속의 촉매들은 함침법에 의해 준비하였고, XRD, XPS 분석을 통하여 특성 분석하였다. Pd-Ru, Pd-Ir 촉매는 다양한 활성점을 나타내었고, 그것은 Pd의 metal 영역를 강화시켰다. 합금금속으로 이루어진 촉매가 단일 금속으로 이루어진 촉매에 비해 VOCs 전환율이 더 높았다. $H_2O-H_2$ 전처리 기술은 Pd 입자를 고르게 분산시켰다. 이는 촉매의 효율을 증진시키는 효과를 보여주었다. 본 연구에서 Pd에 소량의 Ru, Ir 첨가는 VOCs의 산화반응을 증진시켰고, $TiO_2$ 담체상에서 $H_2O-H_2$ 전처리는 VOCs의 제거효율을 증진시켰다. In this study, noble metals (Pd, Ru, Ir) were supported to $TiO_2$ catalyst. In order to distribute metals uniformly, $H_2O-H_2$ pretreatment technique was used. Xylene, toluene, and MEK were used as reactants. The monometallic or bimetallic catalysts were prepared by the excess wetness impregnation method and were characterized by XRD, and XPS analysis. Pd-Ru, Pd-Ir bimetallic catalysts had multipoint active sites which improved the range of Pd metal state. Bimetallic catalysts had a higher conversion of VOCs than that of monometallic one. The effect of $H_2O-H_2$ pretreatment technique was the enhancement of uniform distribution of Pd particles and promotion of catalytic efficiency. In this study, addition of Ru and Ir metals to Pd promoted oxidation conversion of VOCs. In addition, $H_2O-H_2$ pretreatment promoted removal efficiency of VOCs on the $TiO_2$ support.
Ag/γ-Al<sub>2</sub>O<sub>3</sub> 촉매상에서 탄화수소-SCR(Selective Catalytic Reduction) 연구
김문찬,이철규,Kim, Moon-Chan,Lee, Cheal-Gyu 한국분석과학회 2005 분석과학 Vol.18 No.2
본 연구에서는 자동차의 배출가스중에 포함된 NO를 비선택적 촉매환원법으로 환원시켜 제거하기 위하여 Ag의 함량을 여러 가지로 달리하여 ${\gamma}-Al_2O_3$에 담지한 촉매를 제조하였고, 제조한 촉매에 대하여 온도, 산소농도, 아황산가스농도의 변화에 따른 $NO_x$의 전환율에 대하여 연구하였다. 또한 제조한 촉매의 물성분석을 통하여 촉매의 상태와 $NO_x$의 전환율과의 관계를 알아보았다. 제조한 각각의 촉매에 대하여 반응조건을 여러 가지로 달리하여 반응실험을 한 결과 $Ag/{\gamma}-Al_2O_3$ 촉매는 Ag의 함량이 2 wt%일 때, 그리고 반응온도가 약 $450^{\circ}C$일 때 가장 높은 $NO_x$ 전환율을 나타냈다. 반응실험 전 후의 촉매에 대하여 X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Temperature Programmed Reduction (TPR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS)등의 분석 결과와 반응실험 결과를 비교하여 볼 때 Ag의 산화상태가 잘 유지되지 못하여 고온에서는 $NO_x$ 전환율이 낮아지는 것으로 나타났다. Removal of NO contained in automobile exhaust gas was accomplished by the non-selective catalyst reduction method. The catalysts were prepared through loading of a specific amount of Ag into ${\gamma}-Al_2O_3$. The conversion of $NO_x$ was studied by varying the temperatures, $O_2$ concentrations and $SO_2$ concentrations for the prepared catalysts. The influence of the structure of catalyst to $NO_x$ conversion was followed through the analysis of the physical properties of the prepared catalysts. Experiments were conducted on each of the catalysts by varying the reaction conditions to find an optimum condition. The catalyst $Ag/{\gamma}-Al_2O_3$ shows a highest $NO_x$ conversion when the Ag content was 2 wt% and a reaction temperature of about $450^{\circ}C$. and after conducting the experiments, samples of before and after experiments analyzed using XRD, XPS, TPR, and UV-Vis DRS experiments. The result indicated that when Ag oxide content could not be maintained well at high temperatures $NO_x$ conversion decreased.
수축팽창 운동에 의한 축대칭 마이크로-하이드로-머신의 추진을 위한 수치 시뮬레이션
김문찬(Moon-Chan Kim) 한국전산유체공학회 2001 한국전산유체공학회 학술대회논문집 Vol.2001 No.-
A Numerical simulation for the propulsion of axisymmetric body by contractive and dilative motion is carried out. The present analysis shows that a propulsive force can be obtained in highly viscous fluid by a contractive and dilative motion of axisymmetric body. An axisymmetric analysis code is developed with unstructured grid system for the simulation of complicated motion and geometry. The developed code is validated by comparing with the results of stokes approximation with the problem of uniform flow past a sphere in low Reynolds number(R_n=1). The validated code is applied to the simulation of contractive and dilative motion of body. The simulation is extended to the analysis of waving surface with projecting part for finding out the difference of hydrodynamic performance according to the variation of waving surface configuration. The present study will be the basic research for the development of the propulsor of an axisymmetric micro-hydro-machine.
합성얼음과 냉동얼음을 사용한 쇄빙선의 추진 성능 비교 연구
김문찬(Moon-Chan Kim),임태욱(Tae-Wook Lim),조준철(Jun-Cheol Jo),전호환(Ho-Hwan Chun),왕정용(Jungyong Wang) 한국해양공학회 2009 韓國海洋工學會誌 Vol.23 No.1
This paper reports on experimental investigations of self-propulsion performance with syntehtic (model) ice and refrigerated ice, which were conducted in a typical towing tank and ice tank, respectively. The main purpose of this research was to find the correlation between the self-propulsion performance with synthetic ice in a typical towing tank and that with refrigerated ice in an ice tank. The different stresses between the syntehtic ice and refrigerated ice influenced the self-propulsion performance due to different ice and propeller interactions. A further study on the ice property variation for a self-propulsion performance comparison is to be conducted in the near future.
MDO (Marine Diesel Oil) 에멀젼 연료에 의한 디젤엔진의 배출가스 저감
김문찬(Moon Chan Kim) 大韓環境工學會 2014 대한환경공학회지 Vol.36 No.7
본 연구는 에멀젼 연료의 특성과 배출가스에 관하여 연구하였다. 엔진 배출가스 측정은 엔진 dinamometer로 실시하였다. 유화연료는 연소실내에서 미세폭발을 일으켜 연료를 잘게 쪼개어 주어 smoke를 감소시킨다. 그리고 물이 연소실내의 기화열을 빼앗아 연소실 내부의 온도를 낮추어 NOx 생성을 억제하는 효과를 갖는다. ND-13모드의 각 모드별 배출가스온도가 MDO에 비해 유화연료를 사용했을 때 낮게 나온 것으로 뒷받침 될 수 있었다. 유화연료의 함수율이 증가함에 따라 NOx와 smoke의 배출량은 줄어들었으며, 출력도 함수율 증가에 따라 유화연료 자체의 발열량 감소로 인하여 줄어든 것으로 판단된다. ND-13모드에서 MDO 유화연료를 시험결과 함수율 17% 유화연료의 NOx 감소량은 약 24%, smoke의 총감소량은 약 73%, SO₂ 감소량은 약 11%, 그리고 약 13%의 출력손실을 확인하였다. In this study, the characteristics of emulsified fuel and engine emissions were studied with engine dynamometer. Microexplosion took place in the combustion chamber. While combustion, emulsion fuel scattered to micro particles and it caused to smoke reduction. The heat produced from water vapour reduce the temperature of internal combustion chamber and it caused to inhibition of NOx production. It can be verified by the lower exhaust temperature of each ND-13 mode using emulsion fuel than that of MDO fuel. The NOx and smoke concentration were reduced by increasing water content in emulsion fuel. The power also decreased according to the increment of water content of emulsion fuel because emulsion fuel has low calorific value due to high water content than MDO. As a result of ND-13 mode test with 17% moisture content, it was achieved 24% reduction in NOx production, 76% reduction in smoke density, 11% reduction of SO₂ and 13% reduction in power loss.