• Title/Summary/Keyword: Catalyst generation

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Optimal Metal Dose of Alternative Cathode Catalyst Considering Organic Substances in Single Chamber Microbial Fuel Cells

  • Nam, Joo-Youn;Moon, Chungman;Jeong, Emma;Lee, Won-Tae;Shin, Hang-Sik;Kim, Hyun-Woo
    • Environmental Engineering Research
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    • v.18 no.3
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    • pp.145-150
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    • 2013
  • Optimal preparation guidelines of a cathode catalyst layer by non-precious metal catalysts were evaluated based on electrochemical performance in single-chamber microbial fuel cells (MFCs). Experiments for catalyst loading rate revealed that iron(II) phthalocyanine (FePc) can be a promising alternative, comparable to platinum (Pt) and cobalt tetramethoxyphenylporphyrin (CoTMPP), including effects of substrate concentration. Results showed that using an optimal FePc loading of $1mg/cm^2$ was equivalent to a Pt loading of $0.35mg/cm^2$ on the basis of maximum power density. Given higher loading rates or substrate concentrations, FePc proved to be a better alternative for Pt than CoTMPP. Under the optimal loading rate, it was further revealed that 40 wt% of FePc to carbon support allowed for the best power generation. These results suggest that proper control of the non-precious metal catalyst layer and substrate concentration are highly interrelated, and reveal how those combinations promote the economic power generation of single-chamber MFCs.

Hydrogen Generation from Water Using CdS-ZnS Photocatalysts (CdS-ZnS 광촉매를 이용한 물의 광전기 분해에 의한 수소 발생)

  • Heo, Gwi Suk
    • Transactions of the Korean hydrogen and new energy society
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    • v.1 no.1
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    • pp.9-14
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    • 1989
  • Mixed photocatalyst containing cadmium sulfide and zinc sulfide was prepared on silica gel powder and Nafion film. Photo-irradiation of aqueous mixture containing the photocatalysis generated hydrogen by water cleavage reaction. Use of sodium sulfide as sacrificial reagent help the photo-reaction. Evolution of the hydrogen was measured by gas chromatographic analysis. Composition of the catalyst was determined by atomic absorption spectrophotometer. 0.2 mL of of hydrogen was generated per hour. The maximun catalytic activity was obtained after 8-12 hours later. Hydrogen generation efficiency by the two different catalytic system was compared and showed that the Nafion-based catalyst is more efficient than the silicagel-based catalyst for the photoreaction.

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The Catalytic Combustor for Gas Turbines (가스터빈 촉매연소기의 개발 현황)

  • Lee, Dong-Hun;Lee, Kang-Yeop;Choi, Seong-Man
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.265-272
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    • 2003
  • Some catalytic reactors for industrial/generation gas turbines were reviewed and investigated to understand the current status and future prospect for ultra low NOx catalytic gas turbine combustor. Catalytic reactor which was applied to 1${\sim}$10MW class gas turbine has achieved the ultra low emission corresponding to less than 3ppm NOx and 10ppm CO. But the durability and sizing flexibility of catalyst is needed to improve the catalyst performance for commercial gas turbine operation.

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Computer Simulation of Methanation Reactor with Monolith Catalyst (전산 모델링을 통한 모노리스 촉매형 메탄화 반응기의 성능 특성 연구)

  • Chi, Junhwa;Kim, Sungchul;Hong, Jinpyo
    • Transactions of the Korean hydrogen and new energy society
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    • v.25 no.4
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    • pp.425-435
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    • 2014
  • Simulation studies on catalytic methanation reaction in externally cooled tubular reactor filled with monolithic catalysts were carried out using a general purpose modelling tool $gPROMS^{(R)}$. We investigated the effects of operating parameters such as gas space velocity, temperature and pressure of feeding gas on temperature distribution inside the reactor, overall CO conversion, and chemical composition of product gas. In general, performance of methanation reaction is favored under low temperature and high pressure for a wide range of their values. However, methane production becomes negligible at temperatures below 573K when the reactor temperature is not high enough to ignite methanation reaction. Capacity enhancement of the reactor by increasing gas space velocity and/or gas inlet pressure resulted no significant reduction in reactor performance and heat transfer property of catalyst.

Characteristics of Hydrogen Production from Methanol and Ethanol Using Plasma Reactor and Ozone Decomposition Catalyst (플라즈마 리액터 및 오존분해 촉매를 이용한 메탄올 및 에탄올로부터 수소발생특성)

  • Koo, Bon-Kook;Kim, Yong-Chun;Jang, Mun-Gug;Kim, Jong-Hyun;Park, Jae-Youn;Han, Sang-Bo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.10
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    • pp.116-124
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    • 2011
  • In this work, the effect of the initial concentration of methanol and ethanol, and the addition of oxygen molecules were discussed to improve the hydrogen generation using non-thermal plasma reactor effectively. In addition, the effect of ozone decomposition catalyst of manganese dioxide and its quantity was investigated. First, hydrogen concentration increased until an initial concentration of about 40,000[ppm] of methanol and thereafter it was saturated. Henceforth, hydrogen concentration decreased with increasing the oxygen percent on the carrier gas of nitrogen about both substances. Related with the effect of catalyst, it increased upto 60[g], but it was not changed largely after that. Consequently, it is confirmed that the hybrid process using plasma process and catalytic surface chemical reaction is a very promising way to increase the efficiency of hydrogen generation as investigated in this work.

The effects of conductivity and CNT cathode on electricity generation in air-cathode microbial fuel cell (공기양극 미생물연료전지 시스템에서 전력발생특성에 미치는 전기전도도와 CNT 양극의 영향)

  • Yoo, Kyu-Seon;Park, Hyun-Soo;Song, Young-Chae;Woo, Jung-Hui;Lee, Chae-Young;Chung, Jae-Woo
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.3
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    • pp.355-360
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    • 2012
  • The characteristics of power generation were investigated by changing the electrical conductivity from 10 to 40mS/cm using air-cathode microbial fuel cell, which had graphite fiber fabric(GFF) anode. There were three kinds of cathode used: one was carbon cloth cathode coated with Pt, another was carbon nanotube(CNT) cathode with non-precious catalyst of Fe-Cu-Mn, and the other was carbon nanotube(CNT) cathode without any catalyst. When it was operated in batch mode, power density of 1369.5mW/$m^2$ was achieved at conductivity of 20mS/cm. Power density from MFC with CNT cathode coated with multi-catalyst of Fe-Cu-Mn was shown about 985.55mW/$m^2$, which was 75.1% compared the power density of carbon cloth coated with Pt. This meant that CNT cathode coated with multi-catalyst of Fe-Cu-Mn could be an alternative of carbon cloth cathode.

Study on the Ozone Generation and Decomposition of Trichloroethylene Using Dielectric Ball Materials filled Barrier Discharge (유전체 볼 충진 배리어 방전을 이용한 오존 생성 및 TCE 분해처리에 관한 연구)

  • Han, Sang-Bo
    • Journal of IKEEE
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    • v.23 no.2
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    • pp.431-437
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    • 2019
  • This work was carried out ozone generation and TCE decomposition characteristics using dielectric ball materials filled barrier discharge reactor and catalyst's reactor for ozone decomposition. Ozone concentration generated from $Al_2O_3$ or $TiO_2$ filled barrier discharge reactor was so high compared with non-filled discharge reactor. This reactor is good discharge structure for generating the high ozone concentration. In addition, TCE decomposition rate and COx conversion rate increased using $MnO_2$ filled discharge reactor, because ozone was decomposed at the same discharge space on the surface of $MnO_2$ catalysts. To identify the $MnO_2$ catalytic effects, TCE decomposition rate reached to 100[%] by the decomposition of ozone at $MnO_2$ catalyst's reactor by the arrangement of $Al_2O_3$ filled discharge reactor and $MnO_2$ catalyst reactor. Finally, $MnO_2$ catalyst is good materials for the decomposition of ozone and this process will be useful for decomposing VOCs such as TCE.

Dehydration of Methanol to Dimethyl ether, Ethylene and Propylene over Silica-Doped Sulfated Zirconia

  • Hussain, Syed T.;Mazhar, M.;Gul, Sheraz;Chuang, Karl T;Sanger, Alan R.
    • Bulletin of the Korean Chemical Society
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    • v.27 no.11
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    • pp.1844-1850
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    • 2006
  • Two types of catalyst samples were prepared, one sulfated zirconia and the other silica doped sulfated zirconia. The acidity tests indicate that sulfated zirconia doped with silica has higher concentration and strength of acidic catalyst sites than undoped sulfated zirconia. The acidic surface sites have been characterized using FTIR, NMR, pyridine adsorption, TPD, XRD and nitrogen adsorption. Doping with silica increased the concentration of surface Lewis and Brfnsted acid sites and resulted in generation of proximate acid sites.The activity test indicates that doping sulfated zirconia with silica increases both the acidity and catalytic activity for liquid phase dehydration of methanol at 413-453 K. Methanol is sequentially dehydrated to dimethyl ether and ethylene over both catalysts. Significant amounts of propylene are also formed over the silica-doped catalyst, but not over the undoped catalyst.