Kinetics of the alkali-carbonate catalysed gasification of carbon: 3. H2O gasification

✍ Scribed by Ronald Meijer; Freek Kapteijn; Jacob A. Moulijn

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 988 KB
• Volume: 73
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(94)90015-9

✦ Synopsis

The rates of the alkali catalysed water-gas shift reaction (WCS) and steam gasification of carbon have been studied at 1.5 x 10' Pa total pressure as a function of temperature (8OGlOOOK), feed composition (pure H,O or mixtures of H,O with either CO1, H, or CO), alkali metal (Na, K, Rb, Cs) and K,C03 loading (O-25 wt%). A four step kinetic model is selected which describes the observed temperature dependency of the reaction rates and inhibition by CO, H, and CO,. Only beyond 95&1000K is the catalysed WGS oxygen exchange at thermodynamic equilibrium. In H,O atmospheres, with low CO* or CO contents, the various alkali elements exhibit similar activities due to high dispersion. At higher CO* concentrations the H,O gasification rate is strongly lowered, while CO can completely inhibit H,O gasification, and only the WGS reaction takes place. The effect of potassium loading on the H,O gasification activity is similar to that observed for gasification in CO,.