XPS determination of the forms of nitrogen in coal pyrolysis chars

The N 1s spectra from four pulverized Australian coals and their chars prod uced by pyrolysis for 2 s at 1100 degrees C and 1300 degrees C in a pressur ized furnace are evaluated, with particular reference to the binding energy region above 402 eV. The spectra for the feed coals were broadly similar t o those reported previously for bituminous coals, in that pyrrolic nitrogen was the dominant functional form in each case. A minor component between 4 03 and 404.5 eV was assigned to ammonium nitrogen in liberated mineral matt er. The N Is spectra for the chars were also broadly similar to those expec ted for pyrolysis under intermediate residence time conditions, in that the proportion of pyrrolic nitrogen was no more than half that for the feed co al. Intensity in the 402-404.5 eV region was more consistent with N-O speci es formed post-pyrolysis than similar species formed as intermediates durin g pyrolysis, Copyright (C) 1999 John Wiley & Sons, Ltd.