DISTRIBUTION AND ORIGIN OF ORGANIC SULFUR-COMPOUNDS IN IRATI SHALE OIL

This work presents and discusses the occurrence of the principal organic sulphur compounds found in Irati shale oil (Sao Mateus do Sul, Parana, Brazil) as indicated by a combination of gas chromatography-mass spectrometry analysis, retention time data of standard compounds and, when possible, by co-injection with authentic standards. The amount of sulphur in the shale oil corresponds to approximately 40% of the organic sulphur and to a very small fraction of the total sulphur present in the shale (< 1%). A large predominance of low molecular alkylthiophenes (C2-C5 side chain) and low quantities of benzothiophene, dibenzothiophene and alkyldibenzothiophenes (methyl, dimethyl) were observed, attesting to the immaturity of the sample. The distributions of the alkylthiophenes and the hydrocarbons in the oil are apparently related, suggesting a precursor-product relationship at the time of formation of the sediment.