COAL CHARACTERIZATION USING PYROLYSIS FTIR

In this paper the application of combined slow pyrolysis-Fourier transform infrared spectroscopy to structurally characterize coal is studied. On-line FTIR analysis of evolved gases from pyrolysis reveals marked structural differences in a series of Spanish coals varying in rank from peat to bituminous. Using slow heating conditions the pyrolysis reactions were resolved into separate peaks for the evolution of individual species such as CO2, CO, CH4 and sulphur compounds, giving information on oxygen-containing functional groups, coal decomposition temperature and the thermal stability of sulphur structures. Furthermore, kinetic parameters such as activation energies and frequency factors for these reactions can be calculated from the gas evolution profiles. Additional information on structural units present in coal was obtained by studying pyrolysis tars. The structural parameters deduced from FTIR data indicated that tars seem to be structurally related to parent coals, although, they have higher aliphatic hydrogen content and aromaticity.