Composition and Structure of the Sulfur-Containing Compounds in the Extracts from the Chinese High-Organic-Sulfur Coals

The types and molecular structures of the sulfur-containing compounds in extracts of Chinese high-organic-sulfur coals with different ranks were studied using positive-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and methyl derivatization. The types and molecular structures of sulfur-containing compounds were described from three characteristics: the type of the heteroatom, the distribution of the carbon number, and the condensation degree. Nine types of sulfur-containing compounds were detected in the extracts, including S1, S2, O1S1, O1S2, O2S1, N1S1, N1S2, N2S1, and N1S1O1; these compounds are distributed differently in extracts from different high-sulfur coals according to their different ranks. As coal rank increases, sulfur-containing compounds, which have nitrogen atoms, gradually disappear, and sulfur-containing compounds in coal extracts are characterized by short side chains and high condensation.