A study on devolatilization of large coal particles

A generalized devolatilization model for large coal particles is proposed in this paper. The difference between the present model and previous ones is that the equivalent activation energy, E, and the equivalent frequency factor, K, of coal particle devolatilization are independent of coal type, and depend only on the final temperature, T/sub infinity/ of the coal particles. The relationship between E/K and T/sub infinity/ has been obtained and is found to be universal for all coal types. If the final volatile yield, V/sub infinity/ is determined, the devolatilization processes of a large coal particle for any kind of coal can be predicted by using the present model. This model has been tested with five Chinese coals with quite different properties, diameters ranging from 3 mm to 9 mm, and temperatures ranging from 1173K to 1733K. The calculated results agree with experimental data.