• Title/Summary/Keyword: surface reforming

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Hydrogen Production from Methane Reforming Reactions over Ni/MgO Catalyst

  • Wen Sheng Dong;No, Hyeon Seok;Zhong Wen Liu;Jeon, Gi Won;Park, Sang Eon
    • Bulletin of the Korean Chemical Society
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    • v.22 no.12
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    • pp.1323-1327
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    • 2001
  • The catalyst Ni/MgO (Ni : 15 wt%) has been applied to methane reforming reactions, such as steam reforming of methane (SRM), partial oxidation of methane (POM), and oxy-steam reforming of methane (OSRM). It showed high activity and good stability in all the reforming reactions. Especially, it exhibited stable catalytic performance even in stoichiometric SRM (H2O/CH4 = 1). From TPR and H2 pulse chemisorption results, a strong interaction between NiO and MgO results in a high dispersion of Ni crystallite. Pulse reaction results revealed that both CH4 and O2 are activated on the surface of metallic Ni over the catalyst, and then surface carbon species react with adsorbed oxygen to produce CO.

NUMERICAL STUDY OF STREAM REFORMING IN PRECONVERTER FOR MCFC (MCFC용 프리컨버터 수증기 개질반응의 수치연구)

  • Byun, Do-Hyun;Sohn, Chang-Hyun
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.228-232
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    • 2010
  • In this paper, various operating parameters of stream reforming process from methane in preconverter for MCFC is studied by numerical method. Commercial code is used to simulated the porous catalyst with user subroutine to model three dominant chemical reactions which are Stream Reforming(SR), Water-Gas Shift(WGS), and Direct Stram Reforming(DSR). The hydrogen production is tested with different wall temperature, Gas Hourly Space Velocity(GHSV), and different reactor shapes.

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A Study on the Reaction Characteristics of Steam Reforming Reaction over Catalyzed Porous Membrane (다공성 촉매 분리막을 이용한 수증기 개질 반응 특성 연구)

  • Hong, Sung Chang;Lee, Sang Moon
    • Applied Chemistry for Engineering
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    • v.25 no.2
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    • pp.198-203
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    • 2014
  • In this study, steam reforming reaction and surface characteristics of Ni metal foam plate were investigated. Valence state of Ni could be changed by pretreatment, and metallic Ni species exposed on surface as a active site play important role in steam reforming reaction. Porous catalytic membrane also was prepared by mixing of Ni metal foam plate and Ni-YSZ catalyst to control the pore size and assign the catalytic function in Ni metal foam plate. In SEM analysis results, Pore size of Ni metal foam plate could be controlled and Ni-YSZ catalyst well dispersed on surface. Ni based porous catalytic membrane had a similar steam reforming activity regardless of space velocity.

Pt-Ru, Pt-Ni bi-metallic catalysts for heavy hydrocarbon reforming (고 탄화수소 개질을 위한 Pt-Ru, Pt-Ni 이원금속촉매에 관한 연구)

  • Lee, Sanghp;Bae, Joongmyeon
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.97.2-97.2
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    • 2011
  • Pt-Ru and Pt-Ni bimetallic catalysts were prepared and tested for heavy hydrocarbon reforming. Metals were supported on CGO($Ce_{0.8}Gd_{0.2}O_{2.0-x}$) by incipient wetness method. The prepared catalysts were characterized by Temperature programmed reduction(TPR). Oxidative steam reforming of n-dodecane was conducted to compare the activity of the catalysts. The reforming temperature was varied from $500^{\circ}C$ to $800^{\circ}C$ at fixed $O_2$/C of 0.3, $H_2O$/C of 3.0 and GHSV of 5,000/h.Reduction peaks of metal oxide, surface CGO and bulk CGO were detected. Reduction temperature of metal oxide decreased over the bi-metallic catalysts. It is considered that interaction between metals leads to decrease interaction between metal and oxygen. On the other hands, reduction temperatures of surface CGO were dectected in the order of Pt-Ru > Pt-Ni > Pt. low reduction temperatures of surface CGO indicates the low activation energy for oxygen ion conduction to metal. Oxygen ion conduction is known as de-coking mechanism of ionic conducting supports such as CGO. In activity test, fuel conversion was in the same order of Pt-Ru > Pt-Ni > Pt. Especially, 100% of fuel conversion was obtained over Pt-Ru catalysts at $500^{\circ}C$.

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Steam Reforming of Methane in a Solar Concentrated Receiver Reactor (집광된 태양열을 반응기에서의 메탄 수증기개질 연구)

  • Kim, Ki-Man;Nam, Woo-Seok;Han, Gui-Young;Seo, Tae-Beom;Kang, Yong-Heack
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.172-175
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    • 2006
  • Steam reforming of methane using Xe-arc solar simulator was studied for converting solar radiation into energy foam that one can readily utilize. The Xe-arc lamp produce a spectrum similar to that of the sun. SiC ceramic foam, resist high temp.$(>900^{\circ}C)$, is used to catalytically active foam absorber, and to support of reforming catalyst. The catalyst on the surface of foam were directly irradiated with solar simulated xe-light in order to carry out the steam reforming of methane. The reactor was made of stainless steel and quartz window was located on a place of the xe-light irradiation and temperature was controlled using K-type thermocouple in contact with catalyst located inside the reactor. The result show that a possibility of solar reforming using catalytically active foam absorber is exist.

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Preparation of perovskite-based catalysts and fuel injection system for high durability of diesel reforming (디젤 개질을 위한 페로브스카이트 구조 촉매와 연료주입 시스템의 개발)

  • Rhee, Junki;Park, Sangsun;Shul, Yong-Gun
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.115.2-115.2
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    • 2010
  • Autothermal reforming(ATR) processes of hydrocarbon liquids such as diesel fuels are spotlighted as methods to produce hydrogen for Fuel cell. However, the use of heavy hydrocarbons as feedstocks for hydrogen production causes some problems which increase the catalyst deactivation by the carbon deposition. Coking can be inhibited by increasing the water dissociation on the catalyst surface. This results in catastrophic failure of whole system. Performance degradation of diesel autothermal reforming leads to increase of undesirable hydrocarbons at reformed gases and subsequently decrease the performance. In this study, perovskite-based catalysts were investigated as alternatives to substitute the noble metal catalyst for the ATR of diesel. The investigated perovskite structure was based on LaCrO3. and metals were added at the A-site to enhance oxygen ion mobility, transition metals were doped on the B-site to enhance the reformation. Substituted Lanthanum chromium perovskite were made by aqueous combustion synthesis, which can produce high surface area. And for the homogeneous fuel supply, we made ultrasonic injection system for reforming. We compared durability of evaporation system and ultrasonic system for fuel injection.

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Partial Oxidation of Methane over Ni/SiO2

  • Roh, Hyun-Seog;Dong, Wen-Sheng;Jun, Ki-Won;Liu, Zhong-Wen;Park, Sang-Eon;Oh, Young-Sam
    • Bulletin of the Korean Chemical Society
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    • v.23 no.5
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    • pp.669-673
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    • 2002
  • Ni catalyst (Ni: 15 wt%) supported on precalcined SiO2 has been investigated in reforming reactions of methane to synthesis gas. The catalyst exhibited fairly good activity and stability in partial oxidation of methane (POM), whereas it deactivated in steam reforming of methane (SRM). Pulse reaction results of CH4, O2, and CH4/O2 revealed that Ni/SiO2 has high capability to dissociate methane. The results also revealed that both CH4 and O2 are activated on the surface of metallic Ni, and then surface carbon species react with adsorbed oxygen to produce CO and CO2 depending on the bond strength of the oxygen species on the catalyst surface.

Synthesis of Nano-Colloidal Silica Coated with Silver (은을 코팅한 Nano-Colloidal Silica의 합성)

  • Lee, Joo-Heon;Lim, Yoon-Hee;Ham, Jae-Yong
    • Applied Chemistry for Engineering
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    • v.19 no.1
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    • pp.45-50
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    • 2008
  • The self assembled silver process and silver coating process after surface reforming for silica particle, were investigated to coat the silver to colloidal silica. The effects of silver amounts and reductant amounts on silver coating efficiencies were investigated. The silver coating process after surface reforming for silica particle using MPTS (3-Mercaptopropyl trimethoxysilane) and APTS (3-Aminopropyl trimethoxysilane), showed the higher coating efficiency and better antibacterial effect than the self assembled silver process.

A Study on the Suppression of Carbon Deposition in Solid Oxide Fuel Cells Through Methane Internal Reforming (메탄 내부개질 반응을 통한 고체산화물 연료전지의 탄소침적 억제에 관한 연구)

  • Kang, Yun-Hyeok;Lim, Sung-Kwang;Yoo, Yung-Sung;Park, Jin-Woo;Bae, Joong-Myeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.5
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    • pp.473-481
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    • 2007
  • Compared to other types of fuel cells, SOFC has advantages like a wide output range and the direct use of hydrocarbon fuel without the process of external reforming. Particularly because the direct use of fuel without reforming reaction is closely linked to overall system efficiency, it is a very attractive advantage. We tried the operation with methane. However, although methane has a small number of carbons compared to other hydrocarbon fuels, our experiment found the deposition of carbon on the surface of the SOFC electrode. To overcome the problem, we tried the operation through activating internal reforming. The reason that internal reforming was possible was that SOFC runs at high temperature compared to other fuel cells and its electrode is made of Ni, which functions as a catalyst favorable for steam reforming.

$CO_2$ reforming of $CH_4$ and growth of CNT on Ni catalyst (메탄의 이산화탄소 개질반응과 사용된 Ni 촉매 표면에서의 CNT 성장)

  • Kim, Hee-Yeon;Jeong, Nam-Ho;Song, Kwang-Sup
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.511-512
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    • 2008
  • For the $CO_2$ reforming of $CH_4$, Ni catalyst was supported on La-hexaaluminate or on $\gamma$-$Al_2O_3$. The catalytic activities of Ni/La-hexaaluminate catalysts were measured at $700^{\circ}C$ using gas chromatography (GC) for 72 h, and the reaction was maintained up to 72 hfor the investigation of catalyst deactivation. The surface of each catalyst after 72 h reaction was investigated using SEM and TEM, and the composition of the carbon deposits was investigated by using EA, TPO and TGA. Ni/La-hexaaluminate shows higher resistance to coke deposition than conventional Ni/$Al_2O_3$ which seems to be due to strong interaction between Ni and the support material. As a result of the reforming reaction, various types of carbon deposits were created on catalyst surface and the amounts of them were much smaller in the case of La-hexaaluminate than on $Al_2O_3$.

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