ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Comparison of Single Coal Char Particle Combustion at Different Conditions
K. Holíková, R. Žajdlík, J. Markoš, and Ľ. Jelemenský
Department of Chemical and Biochemical Engineering, Faculty of Chemical and Food Technology,
Slovak University of Technology, SK-812 37 Bratislava
Abstract: Comparison of single coal char particle combustion at different operation modes is presented.
Experiments were carried out applying a thermogravimetric method. During combustion of a single
particle, time dependences of temperature inside the particle, around the particle, and the mass
of particle were measured together with the internal porous structure of particles at different degrees
of burnout. Obtained experimental results have shown that the mechanism of combustion is
strongly dependent on the combustion conditions, especially on the initial temperature and oxygen
content in the inlet gas. At temperatures below 500oC, the limiting factor was the oxygen concentration.
Combustion using the inlet concentration of oxygen below 5 vol. % was governed by the
reaction-diffusion mechanism. If the content of oxygen in the inlet gas exceeded 5 vol. %, combustion
proceeded according to the shell progressive mechanism. At temperatures above 500oC, the
shell progressive mechanism of coal particle combustion was supposed, independently of the oxygen
The problems related to mathematical modelling of the combustion of the single char particle
under condition of reaction-diffusion mechanism are discussed.
Full paper in Portable Document Format: 596aa413.pdf
Chemical Papers 59 (6a) 413–420 (2005)