• Title/Summary/Keyword: 선택적환원촉매

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Long-term Stability of the $V_2O_5/TiO_2$ Honeycomb Catalyst in Flue Gas from Coal Fired Power Plant (석탄화력발전소 배기가스를 이용한 $V_2O_5/TiO_2$ 촉매의 내구성 연구)

  • 이인영;김동화;이정빈;엄희문;지평삼
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.235-236
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    • 1999
  • 보일러와 같은 고정원에서 배출되는 질소산화물을 제거하기 위한 후처리 기술인 선택적촉매환원공정(SCR:Selective Catalytic Reduction)은 안정적이며 탈질효율이 높아 상업적으로 가장 많이 이용되고 있다(Bosch, 1988). 본 연구팀은 가격 및 성능 측면에서 외국산 상업용 촉매와 경쟁할 수 있는 국산 SCR 촉매의 개발을 위하여 국내에서 안료용으로 생산되는 TiO$_2$를 촉매의 담체로 이용, V$_2$O$_{5}$/TiO$_2$ 하니콤 촉매를 제조하여 촉매의 활성 및 특성을 연구 중에 있다(이정빈, 1999).(중략)

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A Study on the Distribution of Injected Urea into the Exhaust Pipe in a SCR System (선택적 환원촉매(SCR)장치에서 배기관내에 분사된 환원제 분포에 관한 연구)

  • Choi, J.H.;Lee, Y.C.;LEE, S.W.;Cho, Y.S.;LEE, S.H.;Oh, S.K.;Dong, Y.H.
    • Journal of Power System Engineering
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    • v.14 no.1
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    • pp.16-21
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    • 2010
  • This research focused on the spray and distribution characteristics of urea solution by applying flow visualization techniques and did durability and driver test on injectors as well. The spray characteristics of urea solution was observed by CCD camera. Also, the distribution characteristics of urea solution was evaluated quantitatively as well by using 3D laser scanner equipment. It was considered that it was reasonable to use the injector for gasoline engine in order to inject the urea. The best distribution chart result was observed near 45cm distance difference between catalyst and urea spray injector. As a result of trapped urea distribution chart analysis, optimal pressure and volumetric flow rates of air and urea were derived in order to improve the distribution of Urea. This information may contribute to provide fundamental data in the future.

DeNO$_{X}$를 위한 선택적환원공정의 저온촉매 특성

  • Choe, Sang-Gi;Choe, Seong-U
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2005.05a
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    • pp.207-209
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    • 2005
  • 현재 고정원에서 상용화 촉매로서 사용되는 V$_{2}$O$_{5}$/TiO$_{2}$계 촉매는 고온 영역에서 최적 활성반응을 보이나 NH$_{3}$의 산화반응으로 인해 NO$_{X}$의 제거효율을 낮추는 원인과 가열설비의 추가적인 설치에 따른 초기 투자비, 운전비용 상승 및 촉매 수명 단축 등의 경제적, 기술적인 문제점을 나타내고 있다. 본 연구에서는 저온 영역에서 높은 활성반응을 나타내는 촉매기술의 SCR적용시 배출가스 온도의 100$^{\circ}C$ 감소에 따른 동력비의 절감과 촉매 수명 연장, 경제적, 기술적인 문제점을 해결할 수 있을 것으로 사료된다.

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A Review of Pilot Plant Studies on Elemental Mercury Oxidation Using Catalytic DeNOxing Systems in MW-Scale Coal Combustion Flue Gases (MW급 석탄연소 배가스에서 탈질촉매시스템을 이용한 원소수은 산화 실증사례)

  • Kim, Moon Hyeon;Nguyen, Thi Phuong Thao
    • Clean Technology
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    • v.27 no.3
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    • pp.207-216
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    • 2021
  • Major anthropogenic emissions of elemental mercury (Hg0) occur from coal-fired power plants, and the emissions can be controlled successfully using NH3-SCR (selective catalytic reduction) systems with catalysts. Although the catalysts can easily convert the gaseous mercury into Hg2+ species, the reactions are greatly dependent on the flue gas constituents and SCR conditions. Numerous deNOxing catalysts have been proposed for considerable reduction in power plant mercury emissions; however, there are few studies to date of elemental mercury oxidation using SCR processes with MW- and full-scale coal-fired boilers. In these flue gas streams, the chemistry of the mercury oxidation is very complicated. Coal types, deNOxing catalytic systems, and operating conditions are critical in determining the extent of the oxidation. Of these parameters, halogen element levels in coals may become a key vehicle for obtaining better Hg0 oxidation efficiency. Such halogens are Cl, Br, and F and the former one is predominant in coals. The chlorine exists in the form of salts and is transformed to gaseous HCl with a trace amount of Cl2 during the course of coal combustion. The HCl acts as a very powerful promoter for high catalytic Hg0 oxidation; however, this can be strongly dependent on the type of coal because of a wide variation in the chlorine contents of coal.

NOx Removal of NH3-SCR Catalysts with Operating Conditions (공정조건에 따른 NH3-SCR용 촉매의 질소산화물 제거특성)

  • Park, Kwang Hee;Cha, Wang Seog
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.5610-5614
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    • 2012
  • Performance of catalyst was studied with various operating conditions for selective catalytic reduction of $NO_x$ with $NH_3$. It is confirmed that catalysts containing Mn and Cu have a good efficiency in the usage of oxygen by the $H_2$-TPR analysis. In the case of catalyst #1, $NO_x$ conversion was decrease with the increase of reaction temperature. But in the case of catalyst #2, $NO_x$ conversion was increased and then remained constant with the increase of reaction temperature. This phenomenon is due to the difference of the $NH_3$ oxidation of both catalysts.

Electroless Ni plating on the polyimide film (폴리이미드 필름에의 무전해 니켈도금)

  • Kim, Yu-Sang;Yun, Hui-Tak
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.316-317
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    • 2015
  • 무전해 도금은 금속이온을 수용액 상태에서 석출시키는 방법으로서 전기를 사용하지 않고 환원제의 자기촉매 방법에 의해 금속을 도금하는 방법이다. 두께를 확보하기 위한 화학적 무전해 도금에서는 환원제를 사용하지만 선택적 도금에서는 환원제를 사용하지 않는 치환도금법이 주로 사용되고 있다. 최근 전자파 차폐, 포장기술의 응용이 확대되면서 정보 통신 스마트폰, 전자기술과 자동차 산업에 많은 고분자 복합도금이 널리 확대되고 있다. 최근 해외에서도 고분자와 비금속재료의 복합도금 기술이 관심을 끌고 있다. 2013년 중국의 J. B. Fei 등은 Ag나노체인 합성물에 필요한 비대칭형의 공유결합으로써 나선형의 자기배열 $AgNO_3$와 멜라민 특성을 보고하였다. 무전해 니켈 복합도금은 내마모성, 내식성과 비금속재료의 선택적인 첨가로 다양한 고분자 첨가물을 적용할 수 있다. 유전상수가 낮고 열적 안정성이 우수하여 노트북 컴퓨터나 스마트폰 표면에 니켈-폴리이미드 복합도금도 개발되고 있다.

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Effect of Metal Loading Methods on the Catalytic Activity for N2O/NO Simultaneous Reduction over Fe/BEA Zeolite Catalyst (Fe/BEA 제올라이트 촉매의 N2O/NO 동시 환원 반응에서 금속 담지 방법이 촉매 활성에 미치는 영향)

  • Jeon, Min-Wook;Lee, Seung-Jae;Ryu, In-Soo;Moon, Seung-Hyun;Rhee, Young Woo;Jeon, Sang Goo
    • Korean Chemical Engineering Research
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    • v.55 no.5
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    • pp.679-684
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    • 2017
  • The influence of catalytic activity on Fe loading methods over Fe/BEA zeolite catalyst in the simultaneous reduction of $N_2O/NO$ has been studied. The Fe/BEA zeolite catalysts were prepared by ion exchange and impregnation. Catalytic tests were carried out in the selective catalytic reduction using ammonia as a reductant to identify the activity of prepared catalysts. The results show that the ion exchanged catalyst exhibited higher NO and $N_2O$ conversions than the impregnated catalysts did. To investigate the difference in catalytic activity, we performed various analyses such as XRD, $H_2-TPR$, $O_2-TPD$ and XPS. It is considered that the increase in the activity of the ion exchange catalyst is due to improved reducibility and increased oxygen desorption rate. In addition, the ion exchange catalyst was found through the XPS analysis that $Fe^{2+}$, which is related to the catalytic activity, is formed about 1.6 times more than the impregnated catalyst.

Reduction of NO Emissions from Diesel Combustion using a Catalytic Filter Reactor (촉매 필터 반응기를 이용한 경유연소 배가스 내의 NO저감)

  • 김지용;이상권;한영욱
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2000.11a
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    • pp.257-258
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    • 2000
  • 산업 발전에 따른 대기오염물질의 배출로 인한 대기오염은 날로 심각해지고 있다. 대기오염물질중 NO는 제어에 대한 관심이 높아지고 있는데 NOx의 배연 처리 기술중 가장 보편화되어 있는 기술은 선택적 촉매 환원법(selective catalytic reduction, SCR)이다. 그중 암모니아(NH$_3$)를 환원제로 사용한 SCR법이 가장 널리 사용되고 있는데 이러한 NH$_3$에 의한 탈질공정은 미반응 NH$_3$의 배출, 경제성 등의 문제점이 있어 다른 환원제 즉 urea나 hydrocarbon을 사용하는 탈질기술의 개발이 요구되고 있으며, 특히 hydrocarbon이나 alcohol 계열을 이용한 SCR법에 대한 연구가 활발하게 진행되고 있다. (중략)

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The effect of moisture on SCR reaction of NMO (Natural Manganese Ore) (천연망간광석 SCR 반응에서 수분의 영향)

  • Kim, Sungsu;Hong, Sungchang
    • Applied Chemistry for Engineering
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    • v.18 no.4
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    • pp.350-355
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    • 2007
  • The effect of moisture in flue gas on SCR reaction of NMO (Natural Manganese Ore) was studied. The experiments were performed over NMO with NO, $NH_3$ at independent condition or simultaneous condition. $NH_3$ can be oxidized at low temperature by the lattice oxygen in NMO catalyst. The concentration of NO and $NO_2$ by $NH_3$ oxidation with moisture is higher above $300^{\circ}C$ than that without moisture. Moisture would competitively adsorb with NO and $NH_3$ on NMO catalyst. It caused poor NOx conversion to compete against $H_2O$. Besides the NOx conversion efficiency was reduced at below $250^{\circ}C$ because of the dipped $H_2O$ competitively adsorbed $NH_3$. The reactivity of NMO varied with the calcination temperature and the optimum calcination temperature was $400^{\circ}C$ regardless $H_2O$.

A Study on Selective Catalytic Reduction(SCR) for the Radioactive Waste Incineration Process (방사성 폐기물 소각공정을 위한 선택적 촉매 환원법 연구)

  • Lee, Han-Soo;Kim, In-Tae;Chung, Hongsuk;Ahn, Do Hee;Kim, Jong-Ho;Yang, Hee-Sung;Hwang, Jae-Young;Kim, Sang-Hwan
    • Applied Chemistry for Engineering
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    • v.7 no.4
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    • pp.670-678
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    • 1996
  • The characterization of catalysts for the selective catalytic reduction(SCR) was investigated to remove NOx discharge from radioactive waste incinerator. The catalyst was prepared by impregnating $V_2O_5$, $MoO_3$, and $SnO_2$ on honeycomb shaped $TiO_2$. The effects of the type of catalysts, reaction temperature, feed composition, and mole ratio of $NH_3/NO$ on the reaction characteristics were evaluated in a laboratory scale reactor. The 10% $V_2O_5/TiO_2$ catalyst showed the highest NO to $N_2$ conversion of 94.4% at $350^{\circ}C$ and the temperature range for higher conversion was broadened by adding thermally stable promoters, $MoO_3$.

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