Application of TG-FTIR analysis to superfine pulverized coal

Thermogravimetric test combined with FTIR analysis is conducted to reveal the yield profile of gaseous species and functional groups, both for conventional and superfine pulverized coal (average particle size below or around 20 μm). Generally speaking, the yield of CO2 is less for superfine pulverized coal particle compared with conventional particle size. Since the content of carbonyl group is reduced, the amount of CO2 released during the pyrolysis is more for coal of lower rank (i.e. Neimenggu bituminous coal). CO yield of Neimenggu coal is greater than Shenhua coal, because more side chains and hydroxyl groups are owned by coal of lower rank. As C[dbnd]O group is likely to be linked to the same compound as C[dbnd]C group, the profile of C[dbnd]O group is similar to C[dbnd]C group. H2O evolution of superfine pulverized coal is higher than conventional particle size, for the impact of mechanochemical force for finer particle may be more prominent. With the decrease of the coal particle size, yield trend of CH4 gradually decreases, indicating that superfine pulverized coal is possibly engaged in NO reduction at the early stage of pyrolysis. © 2018 Elsevier B.V.