Sulphur functionality study of steam pyrolyzed “Mequinenza” lignite using reductive pyrolysis technique coupled with MS and GC/MS detection systems

The following organic sulphur species in demineralised lignite were detected by the “off-line” AP-TPR-GC/MS technique: methyl- and benzenethiols; mono- and disulphides; alkylthiolanes; alkenyl thiophenes; alkylbenzo[b]thiophenes and alkyldibenzo[bd]thiophenes. Their relative intensities as a function of temperature were followed. A strong preponderance of benzo[b]thiophene and its alkylated homologues above 450 °C were observed. Thiophene presence was temperature independent.