The influence of pretreatment conditions on the activity and stability of sodium and potassium catalysts in carbon-steam reactions

✍ Scribed by Teus Wigmans; Johannes C. Göebel; Jacob A. Moulijn

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 706 KB
• Volume: 21
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(83)90094-5

✦ Synopsis

in this study it is shown that the low-pressure steam gasification of activated carbon catalysed by sodium and potassium carbonate, can be characterised by at least three types of activity, that are influenced by the pretreatment temperature and period and by the composition of the gas phase during pretreatment. The relative importance of these three types of catalysis. that manifest themselves at different burn-off levels. and the stability towards different pretreatment conditions appear to depend on the type of alkali metal applied. Sodium appears to have its main activity at lower burn-off levels than potassium. Moreover, potassium and sodium exhibit both an additional low but burn-off independent activity. This study shows that the reported differences between potassium and sodium compounds can be partially attributed to different pretreatment conditions. The results are interpreted in terms of evaporation and solid state reactions, occurrring during pretreatment and gasification.