Mesocarbon microbeads （MCMB） were prepared from coal tar pitch modified by phenolic resin and from the same pitch modified by phenolic resin and hexamethylenetetramine at 440℃ for lh. By investigating the morpholog...Mesocarbon microbeads （MCMB） were prepared from coal tar pitch modified by phenolic resin and from the same pitch modified by phenolic resin and hexamethylenetetramine at 440℃ for lh. By investigating the morphology of mesophase spheres and the structure of the MCMB carbonized at 1000℃ for lh using scanning electron microscope （SEM） and XRD, it was found that phenolic resin accelerated the formation and coalescence of mesophase spheres. Some of the obtained MCMB were hi- or tri-spheres with the distorted microtextural carbon layers. Hexamethylenetetramine in the pitch modified by phenolic resin accelerated the condensation of phenolic resin and consequently expedited the combination of mesophase spheres, which was proved by the formation of some tetra-spheres. Owing to the cross-linkage of the additives, MCMB with complex structure were obtained.展开更多
The ultra fine (<200 nm) inorganic solids (BS) were separated from bitumen which was washed by toluene and centrifugated at 2000 rpm. The result of PAS FTIR and image of TEM showed that the structure of BS particle...The ultra fine (<200 nm) inorganic solids (BS) were separated from bitumen which was washed by toluene and centrifugated at 2000 rpm. The result of PAS FTIR and image of TEM showed that the structure of BS particles was smiliar to that of kaolinite clay. On the surface of BS, both toluene insoluble organic matter and structural OH group are detected at the same time. The surface characteristics imparted a bi-wettable nature to the BS. As a result, the BS is able to stabilize fine water emulsion in the bitumen phase. The organic matter associated with BS is a possible factor of the fouling on catalyst and equipment.展开更多
A vacuum topped Canadian oilsands bitumen （VTB） was subjected to solvent precipitation and subsequently characterized by elemental analysis, gel permeation chromatograph （GPC）, IH-NMR spectroscopy and negative-ion...A vacuum topped Canadian oilsands bitumen （VTB） was subjected to solvent precipitation and subsequently characterized by elemental analysis, gel permeation chromatograph （GPC）, IH-NMR spectroscopy and negative-ion electrospray ionization （ESI） Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS）. Effects of experimental conditions such as solvent types （n-Cs, n-C6, and n-C7）, solvent purity, and solvent washing time on asphaltenes yields, bulk composition, and molecular composition of detectable heteroatom compounds in ESI source were determined. Elemental nitrogen and sulfur were enriched in asphaltenes while elemental oxygen had comparable content in maltenes and asphaltenes. Molecular compo- sition of asphaltenes varies with separation conditions. The N1 and O1 species identified by ESI FT-ICR MS were enriched in maltenes. The 02 species exhibited two different double bond equivalents （DBE） distributions and solubility in normal paraffin solvents, indicating two types of molecular structures. Multi oxygen atom containing compounds mainly detected in asphal- tenes. Compound class distributions are similar for maltenes derived from n-Cs, n-C6, and n-C7 , as well as for asphaltenes. The cyclic paraffin impurities in normal paraffin solvents had a significant influence on asphaltenes yields and heteroatom molecu- lar composition. A portion of neutral N1 species and acidic 02 species adsorbed on asphaltenes could be dissolved by increas- ing washing time. Cautions should be exercised when interpreting the properties and composition of asphaltenes obtained with different experimental conditions.展开更多
基金Supported by the National Natural Science Foundation of China (No.50172034).
文摘Mesocarbon microbeads （MCMB） were prepared from coal tar pitch modified by phenolic resin and from the same pitch modified by phenolic resin and hexamethylenetetramine at 440℃ for lh. By investigating the morphology of mesophase spheres and the structure of the MCMB carbonized at 1000℃ for lh using scanning electron microscope （SEM） and XRD, it was found that phenolic resin accelerated the formation and coalescence of mesophase spheres. Some of the obtained MCMB were hi- or tri-spheres with the distorted microtextural carbon layers. Hexamethylenetetramine in the pitch modified by phenolic resin accelerated the condensation of phenolic resin and consequently expedited the combination of mesophase spheres, which was proved by the formation of some tetra-spheres. Owing to the cross-linkage of the additives, MCMB with complex structure were obtained.
基金Financially supported by the Opening Fund of National Key Laboratory of State Heavy Oil University of Petroleum+1 种基金 Beijing (2003-04) and the Scientific Research Foundation (SRF) for the Returned Overseas Chinese Scholars (ROCS) State Education Minis
文摘The ultra fine (<200 nm) inorganic solids (BS) were separated from bitumen which was washed by toluene and centrifugated at 2000 rpm. The result of PAS FTIR and image of TEM showed that the structure of BS particles was smiliar to that of kaolinite clay. On the surface of BS, both toluene insoluble organic matter and structural OH group are detected at the same time. The surface characteristics imparted a bi-wettable nature to the BS. As a result, the BS is able to stabilize fine water emulsion in the bitumen phase. The organic matter associated with BS is a possible factor of the fouling on catalyst and equipment.
基金supported by the National Natural Science Foundation of China(U1162204 and 21236009)
文摘A vacuum topped Canadian oilsands bitumen （VTB） was subjected to solvent precipitation and subsequently characterized by elemental analysis, gel permeation chromatograph （GPC）, IH-NMR spectroscopy and negative-ion electrospray ionization （ESI） Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS）. Effects of experimental conditions such as solvent types （n-Cs, n-C6, and n-C7）, solvent purity, and solvent washing time on asphaltenes yields, bulk composition, and molecular composition of detectable heteroatom compounds in ESI source were determined. Elemental nitrogen and sulfur were enriched in asphaltenes while elemental oxygen had comparable content in maltenes and asphaltenes. Molecular compo- sition of asphaltenes varies with separation conditions. The N1 and O1 species identified by ESI FT-ICR MS were enriched in maltenes. The 02 species exhibited two different double bond equivalents （DBE） distributions and solubility in normal paraffin solvents, indicating two types of molecular structures. Multi oxygen atom containing compounds mainly detected in asphal- tenes. Compound class distributions are similar for maltenes derived from n-Cs, n-C6, and n-C7 , as well as for asphaltenes. The cyclic paraffin impurities in normal paraffin solvents had a significant influence on asphaltenes yields and heteroatom molecu- lar composition. A portion of neutral N1 species and acidic 02 species adsorbed on asphaltenes could be dissolved by increas- ing washing time. Cautions should be exercised when interpreting the properties and composition of asphaltenes obtained with different experimental conditions.
