1986 Volume 12 Issue 5 Pages 569-574
Most conventional studies of the kinetics of coal liquefaction have been concerned only with the weight decrease of residue. However, it is important to study the coal particle size change to design the residue separation process. Therefore, liquefaction experiments were carried out with 16/20 mesh Taiheiyo coal, and the changes in residue weight, particles size and density were investigated.
It was demonstrated that the reaction could be divided into three regions on the basis of density change : I. Both apparent and intrinsic densities change considerably, and particles swell rapidly. II Only the apparent density becomes constant and particles shrink slowly. III. Both densities become constant, and particles shrink slowly and steadily.
Regions II and III were analyzed by new models, in which changes in both residue weight and particle size were considered : the double shrinking core model, which is combined with the shrinking core model and the parallel reaction model, was applied to region II, and the shrinking core model was applied to region III. The validity of these models was confirmed.
