Catalytic activity of alkali and transition metal salt mixtures for steam-char gasification

✍ Scribed by Woon Jae Lee; Sang Done Kim

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 905 KB
• Volume: 74
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(95)00081-f

✦ Synopsis

The catalytic activities of pure and mixed catalysts of alkali and transition metal salts in steam-char gasification at 700-850°C were measured with a thermobalance. The effects of catalyst loading (O-35 wt%) and composition, coal rank and steam partial pressure were determined. The initial rate increases with increasing steam partial pressure in non-catalytic gasification but is almost independent of it in catalytic gasification. The catalytic activities of single salts are in the order K&O3 > Ni(N03), > KzS04 M Ba(N03)z > FeS04. The gasification rate with K2S04 can be enhanced by addition of other salts and the order of catalytic activity of the salt mixtures tested is K2S04 f Ni(N03)2 > KzS04 + Ba(N03)* x K2S04 + FeS04. The char reactivity increases with increasing catalyst loading for K2S04 + Ni(N03)2 and with gasification temperature. The catalytic effectiveness of K2S04 + Ni(N03)2 decreases with increasing coal rank. An equimolar mixture of K2S04 and Ni(N03)2 exhibits the highest catalytic activity and a synergistic effect.