On Internal Temperature Gradients in a Pyrolysing Coal Particle

Abstract

This paper stresses the point that, contrary to common notion, temperature gradients do exist in pulverized coal particles, and that such gradients may or may not be important, depending on the coal thermal properties. Such properties are not routinely measured and are not well documented. In general a particle heats up by an inward moving “heat wave” which is followed by a “pyrolysis wave”. The pyrolysis rate is a function of time and position as described by an “onion peel” model.