• 제목/요약/키워드: Catalytic property

검색결과 117건 처리시간 0.028초

Lined Pipe의 응력해석을 위한 등가 물성치 계산 (Equivalent Mechanical Property for Stress Analysis on Lined Pipe)

  • 최재승;정진한
    • 대한기계학회논문집A
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    • 제26권3호
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    • pp.445-451
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    • 2002
  • The refractory-lined pipe is used to protect the system from high-temperature of the internal flow. The property of the refractory has an effect upon the stress analysis for fluid catalytic cracking(FCC) unit piping design. The equivalent elastic modulus and density considering steel and refractory must be applied in the stress analysis of the system. In the research, the theoretical method to obtain the value of the equivalent property is introduced and then the parametric analysis is carried out to understand the characteristic of the material properties, and the stress analysis is performed with reactor, the part of FCC unit.

NO REDUCTION PROPERTY OF Pt-V2O5-WO3/TiO2 CATALYST SUPPORTED ON PRD-66 CERAMIC FILTER

  • Kim, Young-Ae;Choi, Joo-Hong;Bak, Young-Cheol
    • Environmental Engineering Research
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    • 제10권5호
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    • pp.239-246
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    • 2005
  • The effect of Pt addition over $V_2O_5-WO_3/TiO_2$ catalyst supported on PRO-66 was investigated for NO reduction in order to develop the catalytic filter working at low temperature. Catalytic filters, $Pt-V_2O_5-WO_3/TiO_2/PRD$, were prepared by co-impregnation of Pt, V, and W precursors on $TiO_2$-coated ceramic filter named PRD (PRD-66). Titania was coated onto the pore surface of the ceramic filter using a vacuum aided-dip coating method. The Pt-loaded catalytic filter shifted the optimum working temperature from $260-320^{\circ}C$(for the catalytic filter without Pt addition) to $190-240^{\circ}C$, reducing 700 ppm NO to achieve the $N_x$ slip concentration($N_x\;=\;NO+N_2O+NO_2+NH_3$) less than 20 ppm at the face velocity of 2 cm/s. $Pt-V_2O_5-WO_3/TiO_2$ supported on PRD showed the similar catalytic activity for NO reduction with that supported on SiC filter as reported in a previous study, which implies the ceramic filter itself has no considerable interaction for the catalytic activity.

Lined Pipe 해석을 위한 등가 탄성계수 계산 (Equivalent Elastic Modulus for Lined Pipe Analysis)

  • 정진한;최재승;하대홍
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.547-550
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    • 2000
  • The steel pipe for fluid catalytic cracking(FCC) unit. petroleum refinery, is lined with refractory to protect the system from high-temperature of the internal flow. The property of the refractory has an effect upon the stress analysis of FCC unit. Because 1-D pipe element or 3-D shell element are usually used in commercial codes of stress analysis to evaluate the structural soundness, the equivalent elastic modulus considering steel and refractory should be applied. In the research, the theoretical method to obtain the value of the equivalent property is introduced and then the stress analysis is carried out with the part of FCC unit.

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촉매를 고려한 배압 계산에서의 인자 결정 연구 (Parameter Study of Exhaust Pressure in Catalytic Converter)

  • 이원근;임효재
    • 한국자동차공학회논문집
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    • 제11권5호
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    • pp.77-82
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    • 2003
  • A parametric study was conducted on pressure drop in a catalytic converter for automobile. In this work, we proposed a new pressure drop relation which contains the various parameters needed to calculate and got a few results. In a monolith of catalyst, the flow originally turbulent flow changes to laminar flow and thus the pressure drop through the monolith is linearly proportional to the velocity. The exhaust pressure is doubly affected by the increase of mean velocity and length when we decrease the diameter of monolith while the volume keeps constant. Theoretical parameters such as $\alpha$ and $\beta$ are suggested to use as a reference value when there is no a experimental data. Especially in the part load test, these values should be modified to consider the property change of exhaust gas.

A Study on the Sulfur-Resistant Catalysts for Water Gas Shift Reaction III. Modification of $Mo/γ-Al_2O_3$ Catalyst with Iron Group Metals

  • 박진남;김재현;이호인
    • Bulletin of the Korean Chemical Society
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    • 제21권12호
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    • pp.1233-1238
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    • 2000
  • $Mo/{\gamma}-Al_2O_3catalysts$ modified with Fe, Co, and Ni were prepared by impregnation method and catalytic activity for water gas shift reaction was examined. The optimum amount of Mo loaded for the reaction was 10 wt% $MoO_3$ to ${\gamma}-Al_2O_3.$ The catalytic activity of $MoO_3/{\gamma}-Al_2O_3was$ increased by modifying with Fe, Co, and Ni in the order of Co${\thickapprox}$ Ni > Fe. The optimum amounts of Co and Ni added were 3 wt% based on CoO and NiO to 10 wt% $MoO_3/{\gamma}-Al_2O_3$, restectively. The TPR (temperature-programmed reduction) analysis revealed that the addition of Co and Ni enganced the reducibility of the catalysts. The results of both catalytic activity and TPR experiments strongly suggest that the redox property of the catalyst is an important factor in water gas shift reaction on the sulfided Mo catalysts, which could be an evidence of oxy-sulfide redox mechanism.

메탄-산소 혼합가스 조건에서의 페롭스카이트계 산화물의 촉매특성 평가 (Catalytic Characteristics of Perovskite-type Oxides under Mixed Methane and Oxygen Gases)

  • 안기용;김형철;정용재;손지원;이해원;이종호
    • 한국세라믹학회지
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    • 제45권4호
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    • pp.232-237
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    • 2008
  • As the single chamber SOFC(SC-SOFC) showed higher prospect on reducing the operation temperature as well as offering higher design flexibility of SOFCs, lots of concerns have been given to investigate the catalytic activity of perovskite-type oxide in mixed fuel and oxidant conditions. Hence we thoroughly investigated the catalytic property of various perovskite-type oxides such as $La_{0.8}Sr_{0.2}MnO_3(LSM),\;La_{0.6}Sr_{0.4}CoO_3(LSC),\;La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3(LSCF),\;Sm_{0.5}Sr_{0.5}CoO_3(SSC),\;and\;Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}(BSCF)$ under the partial oxidation condition of methane which used to be given for SC-SOFC operation. In this study, powder form of each perovskite oxides whose surface areas were controlled to be equal, were investigated as functions of methane to oxygen ratios and reactor temperature. XRD, BET and SEM were employed to characterize the crystalline phase, surface area and microstructure of prepared powders before and after the catalytic oxidation. According to the gas phase analysis with flow-through type reactor and gas chromatography system, LSC, SSC, and LSCF showed higher catalytic activity at fairly lower temperature around $400^{\circ}C{\sim}450^{\circ}C$ whereas LSM and BSCF could be activated at much higher temperature above $600^{\circ}C$.

Microwave Assisted Synthesis of Graphene-Bi2MoO6 Nanocomposite as Sono-Photocatalyst

  • Tang, Jia-Yao;Zhu, Lei;Fan, Jia-Yi;Sun, Chen;Oh, Won-Chun
    • 한국재료학회지
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    • 제32권1호
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    • pp.1-8
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    • 2022
  • In this investigation, Bi2MoO6 deposited graphene nanocomposite (BMG) was synthesized using a simple microwave assisted hydrothermal synthesis method. The synthesized BMG nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy with energy dispersive X-ray analysis, and photocurrent analysis. The study revealed that the catalysts prepared have high crystalline nature, enhanced light responsive property, high catalytic activity, and good stability. XRD results of BMG composite exhibit a koechlinite phase of Bi2MoO6. The surface property is shown by SEM and TEM, which confirmed a homogenous composition in the bulk particles of Bi2MoO6 and nanosheets of graphene. The catalytic behavior was investigated by the decomposition of Rhodamine B as a standard dye. The results exhibit excellent yields of product derivatives at mild conditions under ultrasonic/visible light-medium. Approximately 1.6-times-enhanced sono-photocatalytic activity was observed by introduction of Bi2MoO6 on graphene nanosheet compared with control sample P25 during 50 min test.