Evidence for two-site model of char gasification by carbon dioxide

✍ Scribed by P.C. Koenig; R.G. Squires; N.M. Laurendeau

• Book ID: 103002163
• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 691 KB
• Volume: 23
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(85)90089-2

✦ Synopsis

A differential packed-bed reactor has been employed to study the gasification kinetics of Fisher activated coconut char in carbon dioxide/carbon monoxide gas mixtures at a total pressure near 1 atm f 101.3 kPa) and temperatures between 724 and 821°C. The rate data were tested with the generally accepted singlesite Langmuir-Hinshelwood expression. The accepted rate expression predicts linear relationships between inverse rate and 1 /[CO?] for constant or zero [CO], and between inverse rate and [CO] for constant [COl]. For both [CO] and [CO,] 3 IO kPa. these linear relationships existed in agreement with other literature. However, for near-zero [CO], plots of inverse rate vs I /[COJ were not linear. Analysis of other literature supports this result. These observations suggest that the accepted single-site model requires modification. A model involving the two-site adsorption and dissociation of CO? has been proposed which is consistent with the experimental observations obtained here and in the literature.