MELTING BEHAVIORS OF COAL ASH PARTICLES UNDER GASIFICATION CONDITION

摘要

In order to understand well the actual reaction temperature for individual coal/char particle, a novel measurement method has been proposed by Ninomiya. In this method, it was suggested that char particles' heating history would relate to some associated ash particles. This method is based on the following evidences: the morphology of ash particles varies with temperatures, and its variety would mainly depend on their chemical compositions or liquid phase amounts (LPAs) within the ash particles. In general, full-melting particles present as spherical shape and non-melting particles present asolid shape. The morphology or shape and chemical composition can be obtained by SEM-EDS (scanning electron microcopy with an energy dispersive spectrometer). The liquid phase amounts contained in these ash particles with temperatures are calculated by the database of Facility for the Analysis of Chemical Thermodynamics (F~*A~*C~*T). Based on the relationship of the temperature and LPAs, the lower and upper limitation temperatures of these particles could be determined in the LPAs curves for the sphere and solid particles, repectively. This method provides a new way to investigate the heating history of particles during coal gasification or combustion. In order to improve the flexibility and apply in more general conditions, the present work is to investigate the ash particles' melting behavior and the morphology, as well as to establish the relationship between the beated temperature and their liquid phase amounts.