Thermochemical Analysis of U.S. Argonne Premium Coal Samples by Time-Resolved Pyrolysis-Field ionization Mass Spectrometry

Determination of the Forms of Nitrogen Released in Coal Tar During Rapid Devolatilization

“…This result would be consistent with the presence of dimers in the tar, and helps rationalize the difference between the measured value of MW Cl and the reported values of the average tar molecular weight. 3,11,12 The average molecular weight of attachments (MW δ ) in the tar and char are much lower than that found in the parent coals (see Figure 3). While MW δ decreases steadily with rank in the coals, the values of MW δ in the tars change only slightly with rank, with no distinguishable trend.…”

“…Several sets of data indicate that tar molecular weight distributions peak in the range of 250 to 400 daltons. 3,11,12 The tars in this study have molecular weights per cluster in the range of 170 to 240 daltons. These results seem to indicate the presence of species in the tars that contain more that one cluster per molecule (i.e., dimers and trimers rather than monomers).…”

Examination of molecular weight distributions of primary pyrolysis oils from three different oil shales via direct pyrolysis Field Ionization Spectrometry

“…For example, for Green River formation oil shale (from USA) see [16][17][18], for Kukersite oil shale (from Estonia) see [7], for Israeli oil shale see [16] and for Sunbury oil shale (from Kentucky, USA) see [17]. However, there have been several similar direct pyrolysis FIMS studies on coals [19][20][21][22] because from the 1970s to 1990s extensive coal pyrolysis studies were performed, with an emphasize on simultaneously occurring physical and chemical processes [11,12]. The present study is carried out with the view that oil shale and coal have fundamental similarities in their pyrolytic behavior, and thus, the parameters sought mirror those used in one of the advanced coal pyrolysis models, the Functional Group-Depolymerization Vaporization Crosslinking Model [14].…”

Mass spectrometric profiling and pattern recognition

“…In several reviews, this extended research area has been summarized (4, [120][121][122][123]. Major areas of interest are fossil biomaterials such as coals, kerogens, bitumen and asphaltenes (11,77,78,120,(123)(124)(125)(126)(127)(128), and oil shales (122,125). Materials of recent geological history such as peat (129,130), soil humic acids, and soil organic matter (131)(132)(133) have also been investigated (134)(135)(136).…”

“…The specific instrumental requirements of FIlMS and its ionization characteristics, sensitivity, and compound selectivity have been extensively reviewed (3). The technique has been widelyapplied to the characterization of synthetic polymers, biopolymers (3), geochemical s,amples (77,78), and to the investigation of the influence of air pollution on the composition of plant materials such as spruce needles (lo), conifer needles, and beech leaves (65) (Fig. 7).…”