Heteroatom functionality in a high-sulfur Chinese bituminous coal

The forms of nitrogen and sulfur in samples of a high-sulfur Chinese (Guiding) bituminous coal have been investigated by means of X-ray photoelectron spectroscopy (XPS). The N 1s and S 2p spectra were in broad agreement with previously reported data for coal of this type. However, in contrast to the proposition based on this previous work, viz that most of the nitrogen in Guiding coal was in the pyridinic N-oxide and quaternary N forms, it was concluded that most of the organic nitrogen was in pyrrolic form, and that significant quantities of inorganic nitrogen were present in some speciments. Bulk concentrations of ammonium nitrogen, determined directly by a wet chemical method, were in agreement with the surface analytical data. The S 2p spectra indicated that the sulfur was predominantly in thiophenic form.