EFFECT OF SOLVENT BASICITY ON THE KINETICS OF SOLVENT SWELLING OF COAL

This paper describes an investigation of the kinetics of the swelling of a coal of rank 502 in the British Coal classification scheme and th e pyridine-extracted coal in solvents of the same steric properties bu t different basicity: pyridine, 2-chloropyridine and 2-fluoropyridine. The results show that the swelling of the coal and extracted coal in these solvents obeys an experimentally determined first-order rate law for typically all but the first 10% of the swelling. Rate constants a nd apparent activation energies of the swelling of the swelling of the coal increase with increasing solvent basicity. The swelling ratios a nd kinetic parameters for the pyridine-extracted coal do not vary mark edly with the basicity of the pyridines. The results are discussed in terms of structural differences between the raw and pyridine-extracted coals,