Catalysed carbon gasification with Ba13CO3
1986; Elsevier BV; Volume: 65; Issue: 3 Linguagem: Inglês
10.1016/0016-2361(86)90303-0
ISSN1873-7153
AutoresCem Ersolmaz, John L. Falconer,
Tópico(s)Zeolite Catalysis and Synthesis
ResumoThe interaction of barium carbonate with carbon black was studied to understand catalysed CO2 gasification of carbon. Temperature-programmed reaction with isotopic labelling of the carbonate and the carbon showed that carbon dramatically accelerated the rate of BaCO3 decomposition to form BaO and CO2, which rapidly gasified carbon to form CO. Pure BaCO3 was observed to exchange carbon dioxide with the gas-phase, and the exchange rate was increased significantly by carbon at higher temperatures, due to formation of a carbon-carbonate complex. The interaction of BaCO3 and C to form a complex occurred well below gasification temperatures, and BaCO3 did not decompose until after gasification began and the gas phase CO2 concentration was low. During catalysed gasification, formation of gaseous CO from a surface oxide is shown directly to be the slow step in the reaction. The active catalyst appears to cycle between BaCO3 and BaO (both of which interact with carbon). The rates of carbonate decomposition, catalytic gasification, and exchange with gaseous CO2 are all slower for BaCO3 than for K2CO3, indicating the large differences in carbonate-carbon interaction between alkali carbonates and alkaline earth carbonates. The two carbonates apparently follow different reaction mechanisms.
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