Char-wall Interaction and Properties of Slag Waste in Entrained-Flow Gasification of coal

Entrained-flow (EF) gasifiers are characterized by operating conditions so as to favor ash migration/deposition onto the reactor walls, whence the molten ash flows. Studies concerning the fate of char particles as they impinge on the wall slag layer has shed light on the relative importance of the parallel pathways of coal conversion consisting of EF of carbon particles in a lean-dispersed gas phase versus segregated flow of particles in a near-wall region of the gasifier promoted by particle migration and interaction with the molten slag. Theoretical criteria for both char particle entrapment inside and carbon-coverage of the wall ash layer have been developed. The aim of this communication is to investigate the properties of a slag waste coming from an EF gasifier, and to consider the results in the light of the recently-published theoretical and experimental papers on this subject.