Characterization of asphaltene isolated from low-temperature coal tar

Asphaltenes: Separations, structural analysis and applications

“…The FTIR spectrum of coal-derived asphaltene differed from those of petroleum asphaltenes [167] . Specifically, strong absorption peaks in the region of 360 0-330 0/cm were arised from ether oxygen, OH functional groups, and self-associated N-H/O-H hydrogen bonds.…”

“…While, long aliphatic chains of petroleum asphaltene usually had intense signals in the regions of 30 0 0-280 0/cm (saturated C-H stretching), 150 0-130 0/cm (saturated C-H bending), and 725-720/cm (CH 2 of -(CH 2 ) n -, n ≥ 4 rocking vibration) [169,170] . Additionally, obvious bands at about 2500/cm and 1032/cm, corresponding to S-H vibrations and S = O groups of petroleum asphaltene, but they were insignificant in spectrum of coal-derived asphaltene [167] .…”

“…XPS studies showed the types of C-C and C-H were the most carbon-containing compounds both in coal-derived asphaltene and petroleum asphaltene [167] . But, it was difficult to distinguish carbon in aromatic from carbon in non-aromatic structures by XPS.…”

Development, Status, and Prospects of Coal Tar Hydrogenation Technology

“…[2] In this regard,c oal tar is emerginga sa na lternative source of feedstockt ot he refiners for producing transportation fuels.C oal tar is ac omplex mixture consistingo fa liphatic, aromatic, alicyclic,a nd heterocyclic compounds. [3,4] According to the different pyrolysis temperatures and processes, coal tar can be divided into high-temperature (HCT 900-1000 8C), middle-temperature (MCT 650-900 8C), and lowtemperature coal tar (LCT 450-650 8C). [3][4][5][6] Due to the high density and high contents of asphaltene and heterocyclic compounds in HCT,t here are more stringent requirements for the catalyst and reactor of hydrotreatment (HDT) during processing,a nd it is difficult to controlt he reaction rate.…”

“…[3,4] According to the different pyrolysis temperatures and processes, coal tar can be divided into high-temperature (HCT 900-1000 8C), middle-temperature (MCT 650-900 8C), and lowtemperature coal tar (LCT 450-650 8C). [3][4][5][6] Due to the high density and high contents of asphaltene and heterocyclic compounds in HCT,t here are more stringent requirements for the catalyst and reactor of hydrotreatment (HDT) during processing,a nd it is difficult to controlt he reaction rate. [6] Thec ompositiona nd properties of mid-to-low-temperature coal tar are different from that of HCT.I tc ontains more oxygenated compounds and chain hydrocarbons.T he quality content of phenol and its derivatives is up to 10-30 %.…”