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 the pyridine-extracted coal in solvents of the same steric properties but 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 and apparent activation energies of the swelling of the swelling of the coal increase with increasing solvent basicity. The swelling ratios and kinetic parameters for the pyridine-extracted coal do not vary markedly with the basicity of the pyridines. The results are discussed in terms of structural differences between the raw and pyridine-extracted coals,