Synthesis gas is prepared by contacting coal-derived char particles with steam in a fluid-bed gasifier wherein heat for the endothermic reaction is supplied by passing through the gasifier a stream of inert pellets heated externally of the gasifier. The pellets, after leaving the gasifier, are separated...http://www.google.es/patents/US3968052?utm_source=gb-gplus-sharePatente US3968052 - Synthesis gas manufacture
