THE KINETICS OF COAL SOLVENT SWELLING USING PYRIDINE AS SOLVENT

This paper describes an investigation of the kinetics of coal solvent swelling of five coals ranging in rank from 501 to 902 in the British Coal classification scheme using pyridine as solvent. The results cove ring the range 20-60-degrees-C show that the overall kinetics for the major part of the swelling follow a first-order rate law. The apparent activation energies for the solvent swelling process range from 31.8 to 44.6 kJ mol-1, and tend to increase with increasing coal rank. The swelling ratios for the coals in the temperature range investigated va ry to only a small extent. The results are consistent with disruption by the pyridine of the hydrogen bonding in the coal, and suggest that the diffusion coefficient changes during the swelling process.