• Title/Summary/Keyword: gas phase reaction

Search Result 451, Processing Time 0.027 seconds

Catalytic Activity Tests in Gas-Liquid Interface over Cu-ZnO/Al2O3 Catalyst for High Pressure Water-Gas-Shift Reaction (고압 WGS 반응을 위한 Cu-ZnO/Al2O3 촉매상에서 기-액 계면 촉매 반응 특성 연구)

  • Kim, Se-Hun;Park, No-Kuk;Lee, Tae-Jin
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.22 no.6
    • /
    • pp.905-912
    • /
    • 2011
  • In this study, the novel concept catalytic reactor was designed for water-gas shift reaction (WGS) under high pressure. The novel concept catalytic reactor was composed of an autoclave, the catalyst, and liquid water. Cu-ZnO/$Al_2O_3$ as the low temperature shift catalyst was used for WGS reaction. WGS in the novel concept catalytic reactor was carried out at the ranges of 150~$250^{\circ}C$ and 30~50 atm. The liquid water was filled at the bottom of the autoclave catalytic reactor and the catalyst of pellet type was located at the gas-liquid water interface. It was concluded that WGS reaction occurred over the surface of catalysts partially wetted with liquid water. The conversion of CO for WGS was also controlled with changing content of Cu and ZnO used as the catalytic active components. Meanwhile, the catalyst of honey comb type coated with Cu-ZnO/$Al_2O_3$ was used in order to increase the contact area between wet-surface of catalyst and the reactants of gas phase. It was confirmed from these experiments that $H_2$/CO ratio of the simulated coal gas increased from 0.5 to 0.8 by WGS at gas-liquid water interface over the wet surface of honey comb type catalyst at $250^{\circ}C$ and 50 atm.

The Kinetics Study of Ozone with Sulfur Dioxide in the Gas Phase (기체 상태에서의 오존과 아황산가스의 반응연구)

  • Young Sik Kwon
    • Journal of the Korean Chemical Society
    • /
    • v.35 no.2
    • /
    • pp.111-118
    • /
    • 1991
  • The kinetic of the gas phase reactions of ozone(0.5 torr) with sulfur dioxide was studied. The SO2 reaction was conducted in the 7∼22 torr range at 90∼155$^{\circ}$C. The reaction rate was faster than the reaction rate of O$_3$ in the presence of CO$_2$ alone. The reaction of O$_3$ with SO$_2$ follows the rate law: -d(O$_3)/dt=k_0(SO_2)(M)(O_3)+2k _1(SO_2)(O_3$). The first term of this rate law arises from a third order molecular reaction predominating in the lower temperature range and gave a rate constant k$_0$ = (9.35 $\pm$ 8.6) ${\times}$ 10$^9$e$^{-(11.05{\pm}2.04)kcal/RT}(M^{-2}s^{-1}$). The second term of the above rate law derived from a second order thermal decomposition reaction which was the major part of the reaction and gave a rate constant k$_0 =(9.35{\pm}8.6){\times}10^9e^{-(11.05{\pm}2.04)kcal/RT}(M^{-2}s^{-1}$). The overall reaction proceeds with kinetics of complex order composed mainly of second order and third order components.

  • PDF

A Study on the Synthesis of Hydrocarbon by Fisher-Tropsch Synthesis over Cobalt Catalysts with High Surface Area Support (비 표면적 큰 코발트계 담지촉매를 사용한 피셔-트롭스 반응에 의한 탄화수소의 제조에 관한 연구)

  • Kim, Chul-Ung;Kim, You-Sung;Jeong, Soon-Yong;Jeong, Kwang-Eun;Chae, Ho-Jeong;Lee, Kwan-Young
    • Journal of the Korean Applied Science and Technology
    • /
    • v.26 no.3
    • /
    • pp.279-287
    • /
    • 2009
  • Fisher-Tropsch synthesis for the production of hydrocarbon from syngas was investigated on 20% cobalt-based catalysts (20% Co/HSA, 20% Co/Si-MMS), which were prepared by home-made supports with high surface areas such as high surface alumina (HSA) and silica mesopores molecular sieve (Si-MMS). In the gas phase reaction by syngas only, 20% Co/Si-MMS catalyst was shown in higher CO conversion and lower carbon dioxide formation than 20% Co/HSA, whereas the olefin selectivity was higher in 20% Co/HSA than in 20% Co/Si-MMS. In the effect of n-hexane added in syngas, the selectivities of $C_{5+}$ and olefin were increased by comparing the supercritical phase reaction with the gas phase reaction in addition to reduce unexpected methane and carbon dioxide.

Synthesis of Mullite Whiskers by Vapor-Solid Reaction in the System of Al(OH)3-SiO2-AlF3 (Al(OH)3-SiO2-AlF3계에서 기상-고상반응에 의한 뮬라이트 휘스커 합성)

  • Lee, Hong-Lim;Kang, Jong-Bong
    • Journal of the Korean Ceramic Society
    • /
    • v.43 no.6 s.289
    • /
    • pp.376-382
    • /
    • 2006
  • In the $Al(OH)_3-SiO_2-AlF_3$ system, leaf-shaped fluorotopaz was first formed at $800^{\circ}C$ and mullite whisker was formed at $1,100^{\circ}C$. The mass transportation of Al and Si as gas phase, the fast reaction and growth, and the absence of liquid phase existence in mullite whisker showed that the formation and growth of mullite was from the solid-vapor reaction.

A Comparative Analysis on characteristics and Manufacture of Methane/Natural Gas Hydrates (메탄/천연가스 하이드레이트의 제조 및 특성 비교 분석)

  • Lee Young-Chul;Cho Byoung-Hak;Baek Young-Soon
    • Journal of the Korean Institute of Gas
    • /
    • v.7 no.3 s.20
    • /
    • pp.32-43
    • /
    • 2003
  • As this paper is observed the phase equilibrium diagram of mono- (methane) and multi-component(natural gas) hydrates, and the hydrate growth behavior is analysed and compared by the experiments during the reaction. The difference of mono and multi-component hydrates is an induction delay time and a plateau region. And the concentration of component of gases is changed during the reaction in multi-component hydrates and the concentration of components is changed during the decomposition of hydrate according to each decomposing rates of gases. At 6 MPa, 276.65 K and 600 rpm, the induction delay time of multi-component hydrate formation is observed shorter than that of mono-component hydrate formation because the hydrate nuclei of gases except methane form faster than those of methane. And the plateau region of mono-component hydrate is observed distinctly at 0.055 mole of $CH_4$/mole of water and that of multi-component hydrate is observed at 0.04 mole of $CH_4$/mole of water.

  • PDF

Evaluation of Ozone for Oxide Superconductor Thin Film Fabrication (산화물 초전도 박막 제작을 위한 오존의 평가)

  • Lim, Jung-Kwan;Park, Yong-Pil;Lee, Hee-Kab
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2004.07b
    • /
    • pp.1230-1233
    • /
    • 2004
  • Ozone is useful oxidizing gas for the fabrication of oxide thin films. Accordingly researching on oxidizing gas is required. In order to obtain high quality oxide thin films, higher ozone concentration is necessary. In this paper oxidation property was evaluated relation between oxide gas pressure and inverse temperature(CuO reaction). The obtained condition was formulated by the fabrication of Cu metal thin film by co-deposition using the ion Beam Sputtering method. Because the CuO phase peak appeared at the XRD evaluation of the CuO thin film using ozone gas, this study has succeeded in the fabrication of the CuO phase at $825^{\circ}C$.

  • PDF

A Study on the Effect of the $CO_2$ Gas on the Growth Mechanism of the Nitrocarburized Layer (연질화층의 성장기구에 미치는 $CO_2$가스의 영향에 관한 연구)

  • Lee, Gu-Hyeon
    • 연구논문집
    • /
    • s.25
    • /
    • pp.175-184
    • /
    • 1995
  • Mechanical properties of the gas nitrocarburized product depend on the surface compound layer and the diffusion zone formed. The compound layer improves the wear resistance, and the corrosion resistance. Though phase composition, pore layer and growth rate of the compound layer varies according to the treatment time, temperature and the kind of the steel substrate, they are strongly influenced by the environmental gas composition. In the current study, the growth behavior of the compound layer and diffusion zone of the carbon steel and the alloy steel upon nitrocarburizing treatment at $570^{\circ}C$, and the phase composition and the variation in the growth rate of the compound layer according to the variation of the gas environment which was the medium of the nitriding and carburizing reaction were investigated.

  • PDF

Characteristics of Oxidizing Gas for BSCCO Thin Film Fabrication (BSCCO 박막 제작을 위한 산화가스의 특성)

  • Lim, Jung-Kwan;Park, Yong-Pil;Jang, Kyung-Uk;Lee, Hee-Kab
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2005.05b
    • /
    • pp.110-113
    • /
    • 2005
  • Ozone is useful oxidizing gas for the fabrication of BSCCO thin films. In order to obtain high quality oxide BSCCO thin films, higher ozone concentration is necessary. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In this paper oxidation property was evaluated relation between oxide gas pressure and inverse temperature(CuO reaction). The obtained condition was formulated by the fabrication of Cu metal thin film by co-deposition using the Ion Beam Sputtering method. Because the CuO phase peak appeared at the XRD evaluation of the CuO thin film using ozone gas, this study has succeeded in the fabrication of the CuO phase at $825^{\circ}C$.

  • PDF