Abstract: Generating methane or synthesis gas from carbon-containing materials, e.g. coal, by reacting part of the carbon with hydrogen in a hydrogenating gasifier to produce a methane containing gas, and reacting the residual carbon with steam in a steam gasifier to produce a raw gas containing synthesis gas, which latter may be converted to hydrogen and directed to the hydrogenation gasifier or may at least in part be used as a product. The steam gasifier is heated with raw gas leaving the hydrogenating gasifier. The hydrogen gas entering the hydrogenation gasifier is heated with the raw gas leaving the steam gasifier. At least part of the methane is reacted with steam to synthesis gas while heat is being supplied.