Carbon dioxide--carbon reaction by oxygen exchange
The exchange of oxygen between carbon dioxide and carbon monoxide that occurs reversibly on carbon surfaces was studied at temperatures of 750 to 850/sup 0/C and a pressure of 1 atmosphere. Carbon-14 was used to detect and measure the exchange reaction. The extent of oxygen exchange was a linear function of composition of the gas mixture, and this relationship was used to evaluate the forward and backward rate constants of the reaction. Equilibrium constants, directly determined for oxygen exchange in this study, agreed well with values in the literature that were derived only by indirect procedures. This result establishes the validity of oxygen exchange in the mechanism of carbon gasification by CO/sub 2/. Rates of carbon gasification were less than an order of magnitude slower than rates of oxygen exchange. Activation energies for these two processes were 58 and 53 kcal/mole, respectively. The closeness in the activation energies argues against any change in the rate-controlling step over a wide temperature span at atmospheric pressure. The role of CO as a retardant on the CO/sub 2/-C reaction, and the nature of the carbon-oxygen complex are also discussed in view of the data obtained.
- Research Organization:
- Bureau of Mines, Pittsburgh, PA (USA). Energy Research Center
- OSTI ID:
- 7312794
- Report Number(s):
- BM-BULL-664
- Country of Publication:
- United States
- Language:
- English
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ACTIVATION ENERGY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON
CARBON 14
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON ISOTOPES
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CHEMICAL REACTIONS
CRYOGENIC FLUIDS
ELEMENTS
ENERGY
EVEN-EVEN NUCLEI
FLUIDS
GASIFICATION
ISOTOPE APPLICATIONS
ISOTOPES
ISOTOPIC EXCHANGE
KINETICS
LIGHT NUCLEI
NONMETALS
NUCLEI
OXIDES
OXYGEN
OXYGEN COMPOUNDS
RADIOISOTOPES
REACTION KINETICS
THERMOCHEMICAL PROCESSES
TRACER TECHNIQUES
VERY HIGH TEMPERATURE
YEARS LIVING RADIOISOTOPES