Dong-Dong Zhang

Investigation on the structural features of Zhundong subbituminous coal through ruthenium ion-catalyzed oxidation

The structural features of Zhundong subbituminous coal (ZSBC) were investigated by ruthenium ion-catalyzed oxidation (RICO) and subsequent analyses with a gas chromatograph/mass spectrometer and an atmospheric-pressure solid analysis probe/time of flight-mass spectrometer (ASAP/TOF-MS). The results suggest that condensed aromatic rings linked by short polymethylene bridged linkages, long side chains, and oxygen-containing groups are predominant in ZSBC. Aliphatic bridged linkages connecting 3 aromatic rings also exist in ZSBC. Several heterocyclic carboxylic acids were produced from RICO of ZSBC. The heterocyclic moieties include tetrahydrofuran, pyridine, pyrazole, benzo[b]thiophene, and dithiole rings, suggesting the existence of oxygen-, nitrogen-, and sulfur-containing building blocks in ZSBC. According to analysis with ASAP/TOF-MS, a series of heavier arenecarboxylic acids were detected in the products from RICO of ZSBC and aromatic rings of the heavier arenepolycarboxylic acids include naphthalene, biphenyl, anthracene, phenylnaphthalene, and methyl(phenyl)tetrahydroanthracene, implying that ZSBC contains highly condensed aromatic rings. The existence of chlorine- and bromine-containing moieties was confirmed by the identification of chlorine- and bromine-containing species produced from RICO of ZSBC.

Characterization of condensed aromatics and heteroatomic species in Yanshan petroleum coke through ruthenium ion-catalyzed oxidation using three mass spectrometers

Ruthenium ion-catalyzed oxidation (RICO) of Yanshan petroleum coke (YPC) was performed to characterize condensed aromatics and heteroatomic species in YPC. The analysis with gas chromatograph/mass spectrometer mainly offers information on the distributions of side chain groups and bridged linkages, while the analyses with atmospheric pressure solid analysis probe/time-of-flight mass spectrometer and direct analysis in real time ion source coupled to time-of-flight mass spectrometer complement information on heteroatomic species and highly condensed aromatic moieties in YPC. The results indicate that YPC is rich in highly condensed aromatic moieties with tiny portions of alkyl/alkenyl side chains and alkyl/cycloalkyl bridged linkages. The organic oxygen, nitrogen, and sulfur exist in different aromatic rings (including isobenzofuran-1,3-dione, dioxoisoindoline, phenylquinoline, pyridine, and thiophene rings) and different functional groups (including methoxy, epoxy, nitro, and cyano groups). The formation of fluorine- and chlorine-containing species reveals the existence of fluorine- and chlorine-containing moieties in YPC. In addition, a series of heavier arenecarboxylic acids were produced from RICO of YPC. Their possible aromatic rings could be naphthalene, biphenyl, anthracene, phenanthrene, dihydroanthracene, dihydrophenanthrene, phenylnaphthalene, and methyl(phenyl)tetrahydroanthracene, further confirming the existence of highly condensed aromatic rings in YPC. This investigation provides an effective approach both for value-added utilization and for understanding the structural features of YPC.

Characterization of Oxygenates in Zhundong Subbituminous Coal by Gas Chromatography/Mass Spectrometry

ABSTRACT Zhundong subbituminous coal was extracted with isometric carbon disulfide/acetone mixed solvent at room temperature and the residue was subjected to thermal dissolution in methanol from 50 to 200°C. According to gas chromatography–mass spectrometric analysis, the soluble portions (SPs) consist of alkanes, alkenes, arenes, phenols, esters, ketones, alcohols, aldehydes, nitrogenates, and sulfonates, among which oxygenates are the most abundant. Raising the dissolution temperature increased the SP yields. Esterification and transesterification resulting in the cleavage of oxygen-containing bridged bonds caused the generation of esters at temperatures over 100°C.