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Schlagwörter:
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Zusammenfassung:
Annually millions of tons of vacuum residues are produced and could be a potentially valuable resource for petrochemistry but the large amount of sulfur is problematic. Removal of sulfur by hydrodesulfurization is inefficient due to the recalcitrance of high-molecular weight aromatic sulfur compounds (PASH). For development of efficient catalysts, structural information of these species is needed. Here the PASHs were isolated from the aromatic fraction of a vacuum residue before and after Hydrodesulfurization. They wer3e selectively opnized through methylation at the sulfur atom to the methylsulfonium salts. Fourier transform ion cyclotron resonance mass spectrometry provided high-resolution data on these high molecular weight compounds. Compoznds containing one and two sulfur atoms were found to dominate withz masses above 1400 Daltons. The methylating process led to very high selectivity for PASHs even in the presence of large amounts of sulfur-free aromatics. Claasification according to hydrogen deficiency and number of heteroatoms showed extensive series of homologous series.
