Characterization of alkali carbonate catalysts for carbon gasification with 18O labeled CO2

✍ Scribed by M.B. Cerfontain; F. Kapteijn; J.A. Moulijn

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 911 KB
• Volume: 26
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(88)90007-3

✦ Synopsis

AbstractStep response experiments with ie02, "CO,, and CO* over alkali carbonate/carbon systems under gasification conditions reveal fast exchange reactions of (1) CO1 between gas phase and the catalyst, (2) oxygen between gas phase CO, and catalyst oxygen, and (3) oxygen between gas phase COz molecules mutualIy, catalysed by the alkali system. In the second case the exchange reactions involve a low temperature contribution due to oxidic clusters and a high temperature cont~bution ascribed to alkali phenolate groups. These reactions are proposed to proceed via a carbonate intermediate formed by chemisorbed CO, and catalyst oxygen. Cs, K, and Na all show the same behavior except that especially at higher loadings Na has the largest tendency to form bulk carbonate that doesn't take part in the exchange reactions. The presence of CO has little influence on the exchange reactions. Calcium exhibits similar catalytic properties but it is a poorer O-scrambling catalyst.