Iron-induced deactivation of Raney and supported nickel methanation catalysts. Semi-annual progress report, September 15, 1978-September 15, 1980
It was concluded that: (1) the deactivation of Ni/Al/sub 2/O/sub 3/ methanation catalysts is caused by particle size growth and surface site blockage (probably by carbon deposition); (2) the particle size growth in Ni/Al/sub 2/O/sub 3/ methanation catalysts results from the formation of volatile Ni(CO)/sub 4/, vapor phase transport and subsequent decomposition of Ni(CO)/sub 4/; (3) a region of safe operation conditions is found, and justified by thermodynamic equilibrium calculations, the proposed criterion is in terms of the equilibrium Ni(CO)/sub 4/ partial pressure, it can also be applied to other Ni/Al/sub 2/O/sub 3/ systems with different loading and/or geometry; (4) the mechanism of methanation in the unsafe region may be different from that in the safe region; and (5) in-situ Moessbauer spectroscopy has been performed for the first time on a working iron catalyst at high pressure Fischer-Tropsch reaction conditions. In our brief studies, it was clearly shown that under these reactions conditions: (A) the top layer of a precipitated iron catalyst bed is present as a chi-carbide phase, and (B) the bottom layer of a precipitated iron catalyst bed may contain appreciable amounts of magnetite, depending on the CO conversion.
- Research Organization:
- Wisconsin Univ., Madison (USA). Dept. of Chemical Engineering
- DOE Contract Number:
- FG21-78ET12248
- OSTI ID:
- 6894048
- Report Number(s):
- DOE/ET/12248-T2
- Country of Publication:
- United States
- Language:
- English
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Iron-induced deactivation of Raney and supported nickel methanation catalysts. Annual progress report, September 15, 1978-September 15, 1980
Deactivation of nickel methanation catalysts induced by the decomposition of iron carbonyl. II. Interactions between iron and nickel
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47 OTHER INSTRUMENTATION
ACTIVATION ENERGY
ARRHENIUS EQUATION
CARBONYLS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL GASIFICATION
DATA
DEACTIVATION
DECOMPOSITION
ELEMENTS
ENERGY
EQUATIONS
EXPERIMENTAL DATA
GAMMA SPECTROMETERS
GASIFICATION
INFORMATION
IRON
KINETICS
MEASURING INSTRUMENTS
METALS
METHANATION
MOESSBAUER EFFECT
MOESSBAUER SPECTROMETERS
NICKEL
NICKEL COMPOUNDS
NUMERICAL DATA
PARTICLE SIZE
REACTION KINETICS
SIZE
SPECTROMETERS
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
THERMODYNAMICS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS