Role of MgO and CaO promoters in Ni-catalyzed hydrogenation reactions of CO and carbon

Journal Article · Sun Mar 01 04:00:00 EST 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90214-3· OSTI ID:7169825

Haga, Tetsuya; Ozaki, Junichi; Suzuki, Kyosuke; Nishiyama, Yoshiyuki ^[1]

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1. Tohoku Univ., Sendai (Japan)

The roles of Mg and Ca promoters in Ni-catalyzed hydrogasification of carbon were investigated with emphasis on nickel dispersion and nickel-carbon interactions during gasification. The dispersion of nickel on carbon, which was estimated by means of XRD, H{sub 2}-TPD, and CO methanation test, was (Ni + Mg){much gt}(Ni + Ca)>Ni. The increased dispersions of nickel by the Mg and Ca added were found to result in the enhanced Ni-C interaction, which was monitored through the desorption of CO from oxygen remaining on carbon, and, therefore, in the promotions of Ni-catalyzed lower-temperature gasification at 400-700 C. The Ca promoter was likely to give surface CaO(COO) species upon heating up to 550 C and release CO{sub 2} above {approximately} 650 C. The CO{sub 2} released is efficiently converted by the nickel adjacent to CaO into CO to create Ni-(O)-C species above 700 C, resulting in acceleration of Ni-catalyzed gasification above 700 C. In situ oxygen transfer to Ni/C during reaction is the most important role played by the Ca promoter.

• OSTI ID: 7169825
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 134:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

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010404* -- Coal
Lignite
& Peat-- Gasification
010408 -- Coal
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& Peat-- C1 Processes-- (1987-)
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM OXIDES
CARBIDES
CARBON
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL GASIFICATION
COHERENT SCATTERING
CONTROL
DESORPTION
DIFFRACTION
DISTRIBUTION
ELEMENTS
GASIFICATION
HYDROGEN
HYDROGENATION
KINETICS
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MASS TRANSFER
METALS
METHANATION
NICKEL
NICKEL CARBIDES
NICKEL COMPOUNDS
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PROMOTERS
QUANTITY RATIO
REACTION KINETICS
SCATTERING
SORPTION
SURFACE PROPERTIES
TEMPERATURE CONTROL
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY DIFFRACTION