Direct determination and quantification of sulphur forms in heavy petroleum and coals

X-ray photoelectron spectroscopy (XPS) was applied to the problem of speciating and quantifying organically bound forms of sulphur in non-volatile and solid hydrocarbons. XPS results from model compounds were used to interpret sulphur 2p signals from coals and heavy petroleum samples in terms of the amounts of alkyl sulphide and thiophen-like forms present. The determination of organic sulphur forms in Illinois No. 6 coal was accomplished by carefully monitoring the contributions due to iron sulphides and sulphates and application of the curve resolution method used with heavy petroleum samples. XPS data indicate that thiophenic sulphur forms the majority of the organic sulphur species in unoxidized Illinois No. 6 and Raša coals.