Method for converting carbon-containing raw material into a combustible product gas

In a method for converting carbon-containing raw material, particularly coal, wood and crude oil, by passing a catalyst in steam in contact with the carbon-containing raw material in a first zone maintained by externally applied heat to effect a gasification reaction which is endothermic overall and promoted by said catalyst to produce a combustible product gas together with a gasification residue containing principally ash, and a minor amount of catalyst and unreacted carbon, the combination therewith of moving the gasification residue to a separate, exothermic second zone maintained as a separate fluidized bed having a higher temperature than said first zone, and passing steam free of the catalyst upward and in contact with the separated gasification residue as said fluidized bed while maintaining a temperature and a pressure in the second zone at which a homogeneous gaseous solution of the catalyst in the steam forms to extract the catalyst from the residue, and feeding said homogeneous gaseous solution from the gasification residue as the catalyst-steam mixture passing in contact with the carbon-containing raw material in the first zone.