• Title/Summary/Keyword: catalytic efficiency

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A Study on the Improvement of Decomposition Efficiency of Organic Substances Using Plasma Process and Catalytic Surface Chemical Reaction (플라즈마 프로세스 및 촉매 표면화학반응에 의한 유기화합물 분해효율 향상에 대한 연구)

  • Han, Sang-Bo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.5
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    • pp.932-938
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    • 2010
  • This paper proposed the effective treatment method for organic substances using the barrier discharge plasma process and catalytic chemical reaction followed from ozone decomposition. The decomposition by the plasma process of organic substances such as trichloroethylene, methyl alcohol, acetone, and dichloromethane carried out, and ozone is generated effectively at the same time. By passing through catalysts, ozone easily decomposed and further decomposed organic substances. And, 2-dimensional distribution of ozone using the optical measurement method is performed to identify the catalytic surface chemical reaction. In addition, CO is easily oxidized into $CO_2$ by this chemical reaction, which might be induced oxygen atom radicals formed at the surface of catalyst from ozone decomposition.

Exhaust Flow Characteristics of Catalytic Converter Adapted to Exhaust Manifold (배기매니폴드 직접부착 촉매장치의 배기 유동특성)

  • Park, Young-Cheol;Lee, Chang-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.7
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    • pp.837-844
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    • 2003
  • The exhaust gas flow in the inlet collector of close coupled catalyst(CCC) adapted to the exhaust manifold is very complex flow because the exhaust gas is a pulsation flow with several port flow. The distribution of gas flow and temperature in inlet collector effect to the efficiency of catalytic converter. In this study, it measures temperatures on several point in inlet collector with two kind of inlet collector volume. And it analyzes with CFD to exhaust manifold and close coupled catalyst for temperature and flow. Comparing to measured and analyzed result, it find increasing of collector volume effects to catalyst temperature distribution and uniformity of catalytic converter

Decomposition of Ethylene Glycol by Catalytic Wet Air Oxidation (촉매습식산화에 의한 Ethylene Glycol의 분해)

  • 안상준;최장승;이동근
    • Textile Coloration and Finishing
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    • v.13 no.4
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    • pp.264-271
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    • 2001
  • Catalytic wet oxidation of ethylene glycol as refractory compound was studied in a batch slurry reactor using lwt% $Pt/A1_2O_3$, lwt% $Pt/TiO_2,\;Mn/CeO_2$(1:1) and 5wt% $Mn/Al_2O_3$. Experiments were conducted to investigate theeffects of temperature, initial ethylene glycol concentration, catalyst dosage and PH on the ethylene glycol decomposition. When compared with the uncatalyzed reaction, the use of catalysts could increase the rate of ethylene glycol decomposition. The lwt% $Pt/A1_2O_3$ catalyst was preferable to the other catalysts for the destructive oxidation of ethylene glycol. The reaction rate was first order with respect to initial concentration of ethylene glycol. In acidic condition the removal efficiency of ethylene glycol was good, but there was a significant leaching of platinum. Small amount of acetic acid, oxalic acid, masonic acid and formic acid as intermediates were detected during catalytic wet air oxidation of ethylene glycol.

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Graphene Based Cu Oxide Nanocomposites for C-N Cross Coupling Reaction

  • Choi, Jong Hoon;Park, Joon B.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.138.2-138.2
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    • 2013
  • Copper oxide is a multi-functional material being used in various research areas including catalysis, electrochemical materials, oxidizing agents etc. Among these areas, we have synthesized and utilized graphene based copper oxide nanocomposites (CuOx/Graphene) for the catalytic applications (C-N cross coupling reaction). Briefly, Cu precursors were anchored on the graphite oxide(GO) sheets being exfoliated and oxidized from graphite powder. Two different crystalline structures of Cu2O and CuO on graphene and GO were prepared by annealing them in Ar and O2 environments, respectively. The morphological and electronic structures were systemically investigated using FT-IR, XRD, XPS, XAFS, and TEM. Here, we demonstrate that the catalytic performance was found to depend on oxidative states and morphological structures of CuOx graphene nanocomposites. The relationship between the structure of copper oxides and catalytic efficiency toward C-N cross coupling reaction will be discussed.

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Size and Shape Effect of Metal Oxides on Hydrocarbon Selective Catalytic Reduction of Nitrogen Oxides (금속 산화물 촉매의 크기와 형태에 따른 질소산화물의 탄화수소 선택적 촉매환원 특성)

  • Ihm, Tae-Heon;Jo, Jin-Oh;Hyun, Young Jin;Mok, Young Sun
    • Journal of the Korean Institute of Gas
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    • v.19 no.5
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    • pp.20-28
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    • 2015
  • This work investigated the size and shape effect of ${\gamma}$-alumina-supported metal oxides on the hydrocarbon selective catalytic reduction of nitrogen oxides. Several metal oxides including Ag, Cu and Ru were used as the catalysts, and n-heptane as the reducing agent. For the Ag/${\gamma}$-alumina catalyst, the $NO_x$ reduction efficiency in the range of $250{\sim}400^{\circ}C$ increased as the size of Ag decreased (20 nm>50 nm>80 nm). The shape effect of metal oxides on the $NO_x$ reduction was examined with spherical- and wire-shape nanoparticles. Under identical condition, higher catalytic activity for $NO_x$ reduction was observed with Ag and Cu wires than with the spheres, while spherical- and wire-shape Ru exhibited similar $NO_x$ reduction efficiency to each other. Among the metal oxides examined, the best catalytic activity for $NO_x$ reduction was obtained with Ag wire, showing almost complete $NO_x$ removal at a temperature of $300^{\circ}C$. For Cu and Ru catalysts, considerable amount of NO was oxidized to $NO_2$, rather than reduced to $N_2$, leading to lower $NO_x$ reduction efficiency.

An experimental study on emission control of HC and CO due to oxidizing catalyst (산화촉매에 의한 자동차 배출가스중 HC 및 CO의 정화에 관한 실험적 연구)

  • 한영출;최규훈
    • Journal of the korean Society of Automotive Engineers
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    • v.3 no.1
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    • pp.46-53
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    • 1981
  • This paper describes emission control of hydrocarbon and carbon-monoxide due to oxidizing catalyst. The experiment was performed on a precious metal pelleted catalyst(Pt). The factors of the efficiency for purification due to oxidizing catalyst are space velocity, temperature, composition of exhaust gas and supplementary air. The experiment was carried out to control the factors of efficiency for purification. The results of experimental study show that temperature of catalytic converter, supplementary air and space velocity affected the efficiency for purification of hydrocarbon and carbon monoxide.

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Low-Temperature Thermal Decomposition of Industrial N-Hexane and Benzene Vapors (산업 발생 노르말헥산과 벤젠 증기의 저온 분해)

  • Jo Wan-Kuen;Lee Joon-Yeob;Kang Jung-Hwan;Shin Seung-Ho;Kwon Ki-Dong;Kim Mo-Geun
    • Journal of Environmental Science International
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    • v.15 no.7
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    • pp.635-642
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    • 2006
  • Present study evaluated the low-temperature destruction of n-hexane and benzene using mesh-type transition-metal platinum(Pt)/stainless steel(SS) catalyst. The parameters tested for the evaluation of catalytic destruction efficiencies of the two volatile organic compounds(VOC) included input concentration, reaction time, reaction temperature, and surface area of catalyst. It was found that the input concentration affected the destruction efficiencies of n-hexane and benzene, but that this input-concentration effect depended upon VOC type. The destruction efficiencies increased as the reaction time increased, but they were similar between two reaction times for benzene(50 and 60 sec), thereby suggesting that high temperatures are not always proper for thermal destruction of VOCs, when considering the destruction efficiency and operation costs of thermal catalytic system together. Similar to the effects of the input concentration on destruction efficiency of VOCs, the reaction temperature influenced the destruction efficiencies of n-hexane and benzene, but this temperature effect depended upon VOC type. As expected, the destruction efficiencies of n-hexane increased as the surface area of catalyst, but for benzene, the increase rate was not significant, thereby suggesting that similar to the effects of the re- action temperature on destruction efficiency of VOCs, high catalyst surface areas are not always proper for economical thermal destruction of VOCs. Depending upon the inlet concentrations and reaction temperatures, almost 100% of both n-hexane and benzene could be destructed, The current results also suggested that when applying the mesh type transition Metal Pt/SS catalyst for the better catalytic pyrolysis of VOC, VOC type should be considered, along with reaction temperature, surface area of catalyst, reaction time and input concentration.

CuO/3Al$_2$O$_3$ㆍ2SiO$_2$, 촉매담지 세라믹 캔들필터를 이용한 먼지/NOx/SOx/HCl 제거기술

  • 문수호;홍민선;이재춘;이동섭
    • Journal of Energy Engineering
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    • v.13 no.2
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    • pp.133-143
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    • 2004
  • Simultaneous removal technology of particulate/NOx/SOx/HCl using CuO/3Al$_2$O$_3$ㆍ2SiO$_2$catalyst impregnated ceramic candle filters is an advanced air pollution process and provides significantly to reduce hazardous gases emitted from coal-fired power plant. This process uses a high-temperature catalytic filter for integrating SOx and HCl reduction through injection an alkali sorbent (such as hydrated lime or sodium bicarbonate), NOx removal through ammonia injection and selective catalytic reduction (SCR), and particulate collection on the catalytic filter surface. The advantages of the process include : compact integration of the emission control technologies into a single component; easy handling of dry sorbent and by-product; and improved SCR catalytic life due to lowered SOx, HCl and particulate levels. CuO/3Al$_2$O$_3$ㆍ2SiO$_2$ catalyst impregnated ceramic candle filters showed a possibility of simultaneous treatment from results which have ascertained high removal efficiency at various combined gases conditions, and in pilot plant test for 3 months, NO conversion was showed 90% over.