With eight coals covering the range of ranks the kinetics of the gasification with water vapour and carbon dioxide at a total pressure of 2.5 MPa with the variation of temperature and partial pressures were studied, using a batchwise operated laboratory fluidized bed reactor. The inorganic components of the coals were analysed for their nature, distribution and quantity. For all coals a partial pressure dependence of the reaction rate was found analogous to pure carbons. Reaction rates that are related to a given carbon conversion increase partly up to highest conversions, which cannot exclusively be explained by an increase of the inner surface. It is concluded that for this the relative enrichment of catalytically active components of the coals is responsible. The correlation of the gasification rates with the nature, content and distribution of the inorganic components is covered by a second part of this study.