The comparison between reactivities of coals and synthetic model coal under oxy-fuel conditions has been conducted in this paper. Experimental results indicate that the thermogravimetric curve shapes of model coal under oxy-fuel conditions are similar to those of real coals. The thermal reaction behaviors of model coal present a striking similarity to those of high volatile lignite. The synthetic model coal can be representative of a real coal in oxy-fuel combustion. Compared to conventional combustion, the combustion process of model coal under oxy-fuel conditions is obviously delayed. In addition, the increase of oxygen concentration can significantly improve the combustion performance of model coal. Kinetics analysis results show that the activation energy of model coal combustion for a given conversion fraction is not constant. (c) 2012 Elsevier B.V. All rights reserved.