For numerical simulation of coal pyrolysis using the fragmentation and diffusionn (FD) model

a numerical method was proposed. The pyrolysis of three kinds of coal in a heated-tube reactor was simulated respectively

and the results were compared with the experimental results and also with the numerical results of FG-DVC model and CPD model. The effect of pyrolysis temperature and particle diameter on coal pyrolysis product was also studied. The accuracy of FD model was higher than FG-DVC model and CPD model

proving that FD model was more applicable for numerical simulation of coal pyrolysis. The gas product increased rapidly by increasing pyrolysis temperature until 1373 K

and then was nearly constant when pyrolysis temperature was higher than 1373 K. The tar product decreased with increasing pyrolysis temperature

and less time was needed to reach the maximum tar amount. The gas product and tar product both decreased by increasing particle diameter of coal

while more time was needed to reach the maximum tar amount.