Ag/γ-Al₂O₃ 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.

티타니아에 담지된 귀금속촉매의 H₂O-H₂ 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.

열안정제에 의한 제전성 폴리에틸렌테레프탈레이트의 고유점도 및 수분율의 거동 변화

김문찬(Moon Chan Kim),이철규(Cheal Gyu Lee) 한국공업화학회 1999 공업화학 Vol.10 No.5

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관광위기에 대한 업종별 인식 비교연구

김문찬(Kim, Moon-Chan),오상훈(Oh, Sang-Hoon),이미진(Lee, Mi-Jin) 한국관광레저학회 2017 한국관광레저학회 학술발표대회 Vol.2017 No.6

The purpose of this study is to examine the perceptive differences on the tourism crisis among various types of tourism business in Jeju. In 2015 Jeju the number of visitors decreased 40-50% during the tourism crisis of MERS. Survey data were collected from 273 local respondents working in various types of tourism business and analysed to test suggested hypotheses. The results of this study were summarized as follows. First, some perceptive differences on the tourism crisis were found between types of tourism business. Second, the level of tourism crisis perception in public sector is higher than private sector. These results imply that preventive or recovery measures on tourism crisis should be considered the perceptive differences across local tourism businesses, and that local government should make common cause with private businesses to deal with tourism crisis.

[환경] Water 수처리를 이용한 귀금속 촉매의 VOCs 산화특성

김문찬(Moon-Chan Kim) 한국분석과학회 2005 분석과학 Vol.18 No.2

Pd/γ-Al2O3의 H2O-H2전처리에 의한 산화 특성

김문찬 ( Moon Chan Kim ),고선환 ( Sun Hwan Ko ),이영종 ( Young Jong Lee ) 한국공업화학회 2007 응용화학 Vol.11 No.1

폐플라스틱 분해 촉매의 특성

김문찬(Moon-Chan Kim),이철규(Cheal-Gyu Lee) 한국분석과학회 2010 분석과학 Vol.23 No.4

[환경] Ag/γ-Al₂O₃촉매상에서 탄화수소-SCR (Selective Catalytic Reduction) 연구

김문찬(Moon-Chan Kim),이철규(Cheal-Gyu Lee) 한국분석과학회 2005 분석과학 Vol.18 No.2

64채널 Multi-Detector Computed Tomography를 이용한 관상동맥검사의 선량

김문찬(Moon-Chan Kim) 대한방사선과학회(구 대한방사선기술학회) 2009 방사선기술과학 Vol.32 No.3

MDCT의 시간분해능 향상과 등방성 해상능(isotrophic resolution) 영상의 획득, 그리거 지능적인 심전도 동조를 바탕으로 하여 심혈관 질화의 효과적인 진단검사로 인정받고 있는 후향적 심전도 동조화(retrospective ECG gating) 하의 coronary CT angiography는 상대적으로 많은 환자선량을 제공함으로 인해 우수한 진단방법으로서의 장점을 반감시키고 있다. 이에 각 장치 제조사에서는 환자선량을 감소시키는 방법의 연구가 활성화되어 왔으며, 이의 일환으로 지능적인 cardiac dose modulation 기술과 전향적 심전도 동조화(prospective ECG gating)를 사용한 sequential scan이 도입되고 있다 이에 본 연구에서는 64 채널 MDCT에서 54kg, 163cm인 여성 인체모형팬덤을 대상으로 하고 형광유리선량계를 사용하여 후향적 심전도 동조화 하의 coronary CT angiography 프로토콜에서 환자선량의 정량적 평가화 환자선량 감소를 위해 본원에서 선택적으로 적용하고 있는 5가지 검사 프로토콜을 적용하였을 경우의 effective dose와 중요 부위의 organ dose 측정 비교하여 다음과 같은 결과를 얻었다. 1) Dose modulation없이 120kVp와 210mAs의 노출조건으로 retrospectively ECG gated helical scan으로 시행한 conventional coronary CT angiography 프로토콜의 effective dose는 17.8mSv였으며, 심장의 organ dose는 103.8mGy였다. 2) 관전압을 120kVp에서 100kVp로 낮추었을 경우 effective dose는 11.0mSv로 conventional coronary CT에 비해 38.2%가 감소하였으며, 심장은 67.3mGy로 45.2%가 감소하였다. 3) Cardiac dose modulation을 적용한 경우 effective dose 13.3mSv로 conventional coronary CT에 비해 25.3%가 감소하였으며, 심장은 80.0mGy로 22.9%가 감소하였다. 4) 100kVp의 저관전압과 cardiac dose modulation을 적용한 경우 effective dose 8.1mSv로 conventional coronary CT angiography에 비해 54.5%가 감소하였으며, 심장은 49.5mGy로 52.3%가 감소하였다. 5) Prospective ECG gating을 사용한 sequential scan을 시행하였을 때 effective dose는 4.9mSv로 conventional coronary CT에 비해 72.5%가 감소하였으며, 심장은 33.8mGy로 67.4%가 감소하였다. 6) 100kVp의 저관전압과 sequential scan을 적용하였을 때 effective dose는 3.0mSv로 conventional coronary CT angiography에 비해 83.2가 감소하였으며, 심장은 17.7mGy로 82.9%가 감소하였다. Purpose : To compare radiation dose for coronary CT angiography (CTA) obtained with 6 examination protocols such as a retrospectively ECG gated helical scan, a prospectively ECG gated sequential scan, low kVp technique, and cardiac dose modulation technique. Materials and Methods : Coronary CTA was performed by using 6 current clinical protocols to evaluate effective dose and organ dose in primary beam area with anthropomorphic female phantom and glass dosimetric system in 64 channel multi-detector CT. After acquiring topograms of frontal and lateral projection with 80kVp and 10mA, main coronary scan was done with 0.35 sec tube rotation time, 40mm collimation(0.625mm×64ea), small scan field of view (32cm diameter), 150mm scan length. Heart beat rate of phantom was maintained 60bpm in ECG gating, IN constant mAs technique 120kVp, 600mA was used, and 100kVp for low kVp technique. In a retrospectively ECG gated helical CT technique 0.22pitch was used. peak mA (600mA) was adopted in range of 40~80% of R-R interval abd 120mA(80% reduction) in others with cardiac dose modulation. And 210mAs was used without cardiac dose modulation. In a prospectively ECG gated sequential CT technique data were acquired at 75% R-R interval (middle diastolic phase in cardiac cycle), and 120msec additional padding of the tube-on time was used. For effective dose calculation region specific conversion factor of dose length product in thorax was used, which was recommended by EUR 16262. Results : The mean effective dose for conventional coronary CTA withour cardiac dose modulation in a retrospectively ECG gated helical scanwas 17.8mSv, and mean organ dose of heart was 103.8mGy. With low kVp and cardiac dose modulation the mean effective dose showed 54.5% reduction, and heart dose showed 52.3% reduction, compared with that of conventional coronary CTA. And at the sequential scan(SnapShot pulse mode) under prospective ECG gating the mean effective dose was 4.9mSv, this represents and 72.5% reduction compared with that of conventional coronary CTA. And heart dose was 33.8mGy, this represents 67.4% reduction. Inthe sequential scan technique under prospective ECG gating with low kVp the mean effective dose was 3.0mSv, this represents an 83.2% reduction compared with that of conventional coronary CTA. And heart dose was 17.1mGy, this represents an 82.9% reduction. Conclusion : In coronary CTA at retrospectively ECG gated helical scan, cardiac dose modulation technique using low kVp reduced dose to 50% above compared with the conventional helical scan. And the prospectively ECG gated sequential scan offers substantially reduced dose compared with the traditional retrospectively ECG gated helical scan.

연구 논문 : LPG-SCR에 의한 질소 산화물 제거

김문찬 ( Moon Chan Kim ) 한국공업화학회 2012 공업화학 Vol.23 No.6

본 연구에서는 LPG (liqufied petroleum gas)를 환원제로 사용하여 질소산화물을 제거하는 SCR (selective catalytic reduction) 반응을 수행하였다. 질소산화물을 제거하기 위하여 HZSM-5 담체위에 Cu와 Fe를 함량을 달리하여 함침 시켜 촉매를 제조하였다. 질소산화물 전환율을 촉매의 종류와 촉매함량, 반응온도를 중심으로 연구하였다. 촉매는 500 ℃에서 공기흐름 분위기에서 3 h 동안 소성시켜 제조하였다. Cu는 1∼4 wt%, Fe는 0.5∼2 wt%가 되게 Si/Al 비가 80인 HZSM-5에 함침 시켰다. 반응실험 결과에 따르면 Cu가 HZSM-5 담체에 3 wt% 담지된 촉매의 전환율이 가장 높았다. 촉매의 특성화를 위하여 XRD, XPS, TPR 분석을 하였다. In this study, selective catalytic reduction (SCR) reaction was performed using liqufied petroleum gas (LPG) as a reductant for removing NOx. The catalysts were manufactured with different amounts of Cu and Fe supported on HZSM-5 in order to remove NOx. The NOx conversion ratio was studied with changing the temperature and the catalyst amount. The catalysts were manufactured by calcination with flowing the ambient air at 500 ℃ for three hours. Cupper of 1∼4 wt% and iron of 0.5∼2 wt% were supported on HZSM-5 of which Si/Al ratio were 80. According to the reaction results, the catalyst which Cu of 3 wt% supported on HZSM-5 showed the highest conversion rate. XRD, XPS, and TPR analysis were also performed for the characterization of catalysts.