• Title/Summary/Keyword: Ni Catalyst

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Steam Reforming of Ethylene Glycol over Ni/Al2O3 Catalysts: Effect of the Preparation Method and Reduction Temperature (Ni/Al2O3 촉매를 사용한 에틸렌글리콜의 수증기 개질 반응: 촉매 제조 방법과 환원온도의 영향)

  • Choi, Dong Hyuck;Park, Jung Eun;Park, Eun Duck
    • Korean Chemical Engineering Research
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    • v.53 no.3
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    • pp.372-381
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    • 2015
  • The effect of preparation method on the catalytic activities of the $Ni/Al_2O_3$ catalysts on steam reforming of ethylene glycol was investigated. The catalysts were prepared with various preparation methods such as an incipient wetness impregnation, wet impregnation, and coprecipitation method. In the case of coprecipitation method, various precipitants such as KOH, $K_2CO_3$, and $NH_4OH$ were compared. The prepared catalysts were characterized by using $N_2$ physisorption, inductively coupled plasma-atomic emission spectroscopy, X-ray diffraction, temperatureprogrammed reduction, pulsed $H_2$ chemisorption, temperature-programmed oxidation, scanning electron microscopy, and thermogravimetric analysis. Among the catalysts reduced at 773 K, the $Ni/Al_2O_3$ catalyst prepared by a coprecipitation with KOH or $K_2CO_3$ as precipitants showed the best catalytic performance. The preparation method affected the particle size of Ni, reducibility of nickel oxides, catalytic performance (activity and stability), and types of coke formed during the reaction. The $Ni/Al_2O_3$ catalyst prepared by a coprecipitation with KOH showed the increasing catalytic activity with an increase in the reduction temperature from 773 to 1173 K because of an increase in the reduction degree of Ni oxide species even though the particle size of Ni increased with increasing reduction temperature.

Methane carbon dioxide reforming for hydrogen production in a compact reformer - a modeling study

  • Ni, Meng
    • Advances in Energy Research
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    • v.1 no.1
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    • pp.53-78
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    • 2013
  • Methane carbon dioxide reforming (MCDR) is a promising way of utilizing greenhouse gas for hydrogen-rich fuel production. Compared with other types of reactors, Compact Reformers (CRs) are efficient for fuel processing. In a CR, a thin solid plate is placed between two porous catalyst layers to enable efficient heat transfer between the two catalyst layers. In this study, the physical and chemical processes of MCDR in a CR are studied numerically with a 2D numerical model. The model considers the multi-component gas transport and heat transfer in the fuel channel and the porous catalyst layer, and the MCDR reaction kinetics in the catalyst layer. The finite volume method (FVM) is used for discretizing the governing equations. The SIMPLEC algorithm is used to couple the pressure and the velocity. Parametrical simulations are conducted to analyze in detail the effects of various operating/structural parameters on the fuel processing behavior.

Synthesis of High Purity Carbon Nano Fibers and Hydrogen from Propane Decomposition

  • Hussain, S.Tajammul;Gul, Sheraz;Mazhar, M.;Larachi, Faical
    • Bulletin of the Korean Chemical Society
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    • v.29 no.2
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    • pp.389-392
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    • 2008
  • High purity carbon nano fibers/tubes (CNF/Ts) which contain 97% pure graphitic carbon are prepared by a new catalytic method. These carbon nano fibers/tubes are ready to use without any further purification. The striking feature of this method is the production of carbon nano fibers/tubes of narrow distribution range. The developed catalytic method also produces pure hydrogen. An additional advantage of this catalytic method is that catalyst can be reused without reactivation. Ni:Cu catalyst system is embodied into SCHOTT-DURAN filter disc of large pore size (40-100 mm). Due to the production of hydrogen in the reaction catalyst stability is enhanced and deactivation process is considerably slowed down.

Field emission display with catalysis cathode film material for graphite nano fiber

  • Kageyama, Kagehiro;Kojima, Tomoaki;Hirakawa, Masaaki;Sasaki, Takaei
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.146-149
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    • 2006
  • We developed new FED cathode film material that has catalysis function for graphite nano fiber. Using the cathode film with catalyst, we can simplify the FED process. It is composed of Cr, Fe-Ni catalyst. Fabricating FED panel with the film, we confirmed good emission performance of the panel.

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Carbon Nanotube Deposition using Helicon Plasma CVD at Low Temperature

  • Muroyama, Masakazu;Kazuto, Kimura;Yagi, Takao;Inoue, Kouji;Saito, Ichiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.201-202
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    • 2003
  • We developed a novel growth method of aligned carbon nanotubes. Aligned carbon nanotubes are grown on a metal catalyst on a glass substrate using biased Helicon plasma chemical vapor deposition (HPECVD) of $CH_4/H_2$ gases from 400 C to 500 C. The Helicon plasma source is one of the high-density plasma sources and is promising for low temperature carbon deposition. A Ni film was used as a catalyst to reduce the activation energy of the nanotubes' growth. The carbon nanotubes were deposited on the nickel catalysis layer selectively.

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Effect of Co and Ni Catalyst on the Preparation of Porous Graphite Using Magadiite Template (Magadiite 주형을 이용한 다공성 흑연제조에 미치는 Co와 Ni 촉매 효과)

  • Choi, Seok-Hyon;Kwon, Oh-Yun
    • Korean Journal of Materials Research
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    • v.28 no.3
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    • pp.189-194
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    • 2018
  • Porous graphites were synthesized by removing the template in HF after cabothermal conversion for 3 h at $900^{\circ}C$, accompanied by intercalations of pyrolyzed fuel oil (PFO) in the interlayer of Co or Ni loaded magadiite. The X-ray powder diffraction pattern of the porous graphites exhibited 00l reflections corresponding to a basal spacing of 0.7 nm. The particle morphology of the porous graphites was composed of carbon plates intergrown to form spherical nodules resembling rosettes like a magadiite template. TEM shows that the cross section of the porous graphites is composed of layers with very regular spaces. In particular, crystallization of the porous graphite was dependent on the content of Co or Ni loaded in the interlayer. The porous graphite had a surface area of $328-477m^2/g$. This indicates that metals such as Co and Ni act as catalysts that accelerate graphite formation.

Kinetics and Mechanisms of the Oxidation of Carbon Monoxide on Ni-Doped $\alpha-Fe_2O_3$

  • Kim, Keu-Hong;Jun, Jong-Ho;Choi, Jae-Shi
    • Bulletin of the Korean Chemical Society
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    • v.5 no.1
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    • pp.41-44
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    • 1984
  • The oxidation of carbon monoxide has been investigated on Ni-doped ${\alpha}-Fe_2O_3$ catalyst at 300 to $450^{\circ}$. The oxidation rates have been correlated with 1.5-order kinetics; first with respect to CO and 1/2 with respect to $O_2$. Carbon monoxide is adsorbed on lattice oxygen of Ni-doped ${\alpha}-Fe_2O_3$, while oxygen appears to be adsorbed on oxygen vacancy formed by Ni-doping. The conductivities show that adsorption of CO on O-lattice produces conduction electron and adsorption of $O_2$ on O-vacancy withdraws the conduction electron from vacancy. The adsorption process of CO on O-lattice is rate-determining step and dominant defect of Ni-doped ${\alpha}-Fe_2O_3$ is suggested from the agreement between kinetic and conductivity data.

A Study on the Performance of Ni Catalysts in Biogas Steam Reforming: Impact of Supports and Precipitation Agent Injection Rates (바이오가스 수증기 개질 반응용 Ni 촉매 성능 연구: 지지체 및 침전제 주입 속도에 따른 영향)

  • Ji-Hyeon Gong;Min-Ju Kim;Kyung-Won Jeon;Won-Jun Jang
    • Clean Technology
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    • v.29 no.4
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    • pp.327-332
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    • 2023
  • This study investigated synthesis gas production via steam reforming of biogas. Ni-Al2O3 and Ni-CeO2 catalysts were synthesized using the co-precipitation method, with controlled precipitation agent injection rates. Catalytic performances were tested at various temperatures, with a gas composition ratio of CH4:CO2:H2O = 1:0.67:3 and a gas hourly space velocity (GHSV) of 647,000 mL h-1 gcat-1. The rate of precipitation agent injection influenced the characteristics of the catalysts depending on the type of support used. As the temperature increased, both the CO2 reforming of methane and the reverse water gas shift reactions occurred. The Ni-Al2O3 catalyst, synthesized with a single injection of the precipitation agent, exhibited the best catalytic activity under conditions with sufficient steam supply among the prepared catalysts, due to its high Ni dispersion.