MATHEMATICAL MODEL FOR CHAR COMBUSTION IN A FLUIDIZED BED.

In view of the recent work pointing to the diffusion of oxygen to the reaction surface of a combusting char particle, the direct oxidation model was developed to formulate mathematically the combustion of char particles. The model is made general by including terms representing the formation of ash layer on the unreacted core of the solid particle as a result of reaction. The two-phase theory of fluidization with constant size bubbles is employed in computing interphase mass transfer from bubbles to the emulsion phase.