Mixtures of potassium sulphate and iron sulphate as catalysts for water vapour gasification of carbon: 3. Chemsitry of the in situ activation of the catalyst

✍ Scribed by Klaus J. Hüttinger; Roland Minges

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 441 KB
• Volume: 64
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(85)90425-9

✦ Synopsis

Previously it was shown that certain mixtures of K2S04 and FeSO, were excellent raw materials for catalytic watervapourgasification of carbon. It was suggested from the results that the iron salt catalyses the reduction of K2S04 to K as the main catalyticly active species of gasification. This paper is concentrated on this activation process. Using TGA, DTA, ESCA, EPMA and visual observations of the melting behaviour after or during treatment of varying K2S04/FeS0, mixtures in H2 and Hz/H,0 atmospheres it is found that elemental iron is formed in an early stage during heating up. This then catalyses the reduction of K2S04 to K2S, which is readily hydrolysed by water vapour to liquid KOH. K2S04 and K2S form an intermediate eutectic (m.p.=610"C), which favours wettability of the carbon surface and hydrolysis of K$. As well as FeS04 any iron salts can be used that are easily reduced to elemental iron in the gasification atmosphere. A general reaction scheme, including activation and catalytic gasification, is proposed. The activation of K2S04 to catalytically active KOH can be described as follows: Fe-salt=Fe 3K,