Sulfur distribution during pyrolysis

To study the effect of chemical composition on sulfur distribution during pyrolysis, it appeared desirable to study the pyrolysis of sulfur-containing model compounds of well-defined structure. The correlation of chemical composition and sulfur distribution during pyrolysis is the subject of this paper. 

A series of 10 polycyclic compounds and blends with starch, Bakelite, and hydrogenated creosote were employed as model substances to examine the effect of carbon, hydrogen, and oxygen on sulfur distribution during pyrolysis at a temperature of about 625°C. 

The relationships among hydroconversion of the coal liquids, sulfur distribution, and other important fuel properties still need to be evaluated. They are part of the S W-Gulf development program now under study. This paper summarizes some of the preliminary investigations carried out as a prelude to the development program. Data on reactions by which aromatic molecules are converted to gas are reviewed and correlated consideration is also given to the formation of aromatic molecules during pyrolysis of hydrocarbons. 

Figure 3.8 shows a distribution pattern of volatiles produced during the heating of PES as measured by a combination of TGA and stepwise pyrolysis-gas chromatography-mass spectrometry [95], which indicates that the major products, sulfur dioxide and phenol, are not produced at temperatures below 450 °C. 

A homogeneous distribution of active sites was obtained when the phenanthroline is pyrolyzed in the presence of iron oxalate. Such catalysts exhibited an excellent performance in RDE measurements, even without sulfur addition [134]. As indicated by a change of color, already during the mixing of the precursors, a complexation of iron with phenanthroline occurs. These catalysts show similar structural features in MoBbauer spectroscopy and exhibit similar iron contents as those catalysts prepared by the oxalate-supported pyrolysis of porphyrins. 

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