Key words: Double-stage coal gasifier  Gasification  Coal  Granularity  Coal property  Caking  Ash softening temperature Volatile matter  Thermal stability  Moisture  Shattering strength
Preface: For coal gasifier-the main equipment for converting solid coal into clean gas, preparation of coal for gasification is great important, which directly affects the whole gasification. For double-stage coal gasifier, bituminous coal such as non-caking coal, weak caking coal, long flame coal are suitable for gasification, besides, lignite of better quality can also be gasified. In short, compared with single-stage coal gasifier, double-stage coal gasifier has a low demand on coal property but concrete coal indexes are strict.