Alkali-catalyzed carbon gasification in CO/CO/sub 2/ mixtures: an extended model for the oxygen exchange and gasification reaction
Based on the results of reactivity measurements and step-response experiments with labeled molecules an extended model for the oxygen exchange and gasification of carbon in CO/CO/sub 2/ atmospheres over alkali carbonate/carbon systems is given. The alkali catalysts studied (Na, K, Cs) contain considerable amounts of chemisorbed CO/sub 2/, nearly temperature and pressure independent, but easily exchangeable with gas-phase CO/sub 2/. For all three catalysts the gasification rate correlates well and in the same way with the amount of chemisorbed CO/sub 2/. Gasification is envisaged as the decomposition of C(O) complexes which are formed by interaction of the catalyst and the carbon. Oxygen exchange is catalyzed by the alkali catalyst species. Carbon-oxygen complexes, C(O), are not involved in this process. The proposed model can account for the observed pressure dependences; i.e., oxygen exchange is only proportional to the CO pressure and the gasification rate is proportional to the ratio of the CO and CO/sub 2/ partial pressures. In both reactions chemisorbed CO/sub 2/ is the important intermediate.
- Research Organization:
- Univ. of Amsterdam (Netherlands)
- OSTI ID:
- 5330937
- Journal Information:
- J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 107:1; ISSN JCTLA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010404* -- Coal
Lignite
& Peat-- Gasification
ALKALI METALS
CARBON
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYTIC EFFECTS
CESIUM
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISORPTION
COAL GASIFICATION
DECOMPOSITION
ELEMENTS
GASIFICATION
KINETICS
MASS TRANSFER
METALS
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
POTASSIUM
PRESSURE DEPENDENCE
REACTION INTERMEDIATES
REACTION KINETICS
SEPARATION PROCESSES
SODIUM
SORPTION
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES