The results of experimental studies of carbon materials, which are formed in the plasma of a direct current (DC) arc discharge initiated in open air from the asphaltenes of different origins, extracted from the natura...The results of experimental studies of carbon materials, which are formed in the plasma of a direct current (DC) arc discharge initiated in open air from the asphaltenes of different origins, extracted from the natural asphaltite and from the oil of the Sredne-Ugutskoye Oilfield, are presented. The influence of the initial asphaltene composition on the composition and properties of the resulting carbon materials is analyzed. The initial asphaltenes and the samples of the carbon materials are characterized by the methods of X-ray diffraction, differential thermal analysis, X-ray fluorescence analysis, IR-Fourier spectroscopy, laser diffraction, transmission and scanning electron microscopy. The changes in the composition and structure of the asphaltenes are determined before and after their plasma treatment and the hypotheses are put forward concerning the chemical processes causing the changes in the molecular structure of the samples. As a result of plasma treatment of asphaltenes (100 A, 30 s), it was shown that graphitization occurs, as well as oxidation, and a decrease in sulfur content. Moreover, nanotubes and nano-onions have been detected using electron microscopy. Petroleum asphaltenes after plasma treatment give a less thermostable carbon material, but with a lower content of heteroatoms, and with a large amount of sulfur in the composition of sulfoxide structural fragments. This method is shown to be a promising technology for processing the petroleum feedstock enriched with heavy asphaltene components for the manufacture of carbon nanomaterials: nanotubes, nano-onions and polyhedral graphite.展开更多
This study presents analysis of asphaltenes isolated from two crude oils:naphthenic-aromatic biodegraded oil and paraffin-naphthenic oil,which have been used as precursors for carbon materials synthesis.The aim of thi...This study presents analysis of asphaltenes isolated from two crude oils:naphthenic-aromatic biodegraded oil and paraffin-naphthenic oil,which have been used as precursors for carbon materials synthesis.The aim of this study is to investigate the interrelationship between the initial structure of asphaltene and the properties of carbon materials.Based on number of spectroscopic and other data,it can be found out that the asphaltenes from napthenic-aromatic biodegraded oil contain less paraffin and more cyclic fragments(aromatic and aliphatic),that are larger and more densely stacked.The asphaltenes of paraffin-naphthenic oil contain a larger number of labile bonds and heteroatoms.Both the asphaltenes contain sulfur enclosed in thiophene and sulfide fragments,nitrogen and oxygen,which are incorporated in different units with different thermal stability.Carbon materials are obtained from both asphaltenes via plasma of an electric arc discharge.The asphaltenes undergo graphitization as a result of plasma treatment,the general trend is an elimination of functional groups and N,S,O.The yields of the carbon materials are almost equal for two studied asphaltenes,giving graphite-like materials as the major product in both cases.The carbon material obtained from the napthenic-aromatic asphaltenes is less thermally stable,the yield of nano-structures and nanofibers are higher compared to the asphaltenes from paraffinic oil,with trace metals remaining during the synthesis process.The carbon material from paraffin-naphthenic oil is amorphous with low heteroatoms content.展开更多
基金funded by a grant from the Russian Science Foundation(Project No.22-13-20016)carried out at the Surgut State University and Tomsk Polytechnic University.
文摘The results of experimental studies of carbon materials, which are formed in the plasma of a direct current (DC) arc discharge initiated in open air from the asphaltenes of different origins, extracted from the natural asphaltite and from the oil of the Sredne-Ugutskoye Oilfield, are presented. The influence of the initial asphaltene composition on the composition and properties of the resulting carbon materials is analyzed. The initial asphaltenes and the samples of the carbon materials are characterized by the methods of X-ray diffraction, differential thermal analysis, X-ray fluorescence analysis, IR-Fourier spectroscopy, laser diffraction, transmission and scanning electron microscopy. The changes in the composition and structure of the asphaltenes are determined before and after their plasma treatment and the hypotheses are put forward concerning the chemical processes causing the changes in the molecular structure of the samples. As a result of plasma treatment of asphaltenes (100 A, 30 s), it was shown that graphitization occurs, as well as oxidation, and a decrease in sulfur content. Moreover, nanotubes and nano-onions have been detected using electron microscopy. Petroleum asphaltenes after plasma treatment give a less thermostable carbon material, but with a lower content of heteroatoms, and with a large amount of sulfur in the composition of sulfoxide structural fragments. This method is shown to be a promising technology for processing the petroleum feedstock enriched with heavy asphaltene components for the manufacture of carbon nanomaterials: nanotubes, nano-onions and polyhedral graphite.
基金funded by a grant from the Russian Science Foundation(Project No.22-13-20016)and carried out at the Surgut State University,Tomsk Polytechnic University and Skolkovo Institute of Science and Technology.The XPS studies were performed using facilities of the Shared Research Center“National center of investigation of catalysts”at Boreskov Institute of Catalysis.
文摘This study presents analysis of asphaltenes isolated from two crude oils:naphthenic-aromatic biodegraded oil and paraffin-naphthenic oil,which have been used as precursors for carbon materials synthesis.The aim of this study is to investigate the interrelationship between the initial structure of asphaltene and the properties of carbon materials.Based on number of spectroscopic and other data,it can be found out that the asphaltenes from napthenic-aromatic biodegraded oil contain less paraffin and more cyclic fragments(aromatic and aliphatic),that are larger and more densely stacked.The asphaltenes of paraffin-naphthenic oil contain a larger number of labile bonds and heteroatoms.Both the asphaltenes contain sulfur enclosed in thiophene and sulfide fragments,nitrogen and oxygen,which are incorporated in different units with different thermal stability.Carbon materials are obtained from both asphaltenes via plasma of an electric arc discharge.The asphaltenes undergo graphitization as a result of plasma treatment,the general trend is an elimination of functional groups and N,S,O.The yields of the carbon materials are almost equal for two studied asphaltenes,giving graphite-like materials as the major product in both cases.The carbon material obtained from the napthenic-aromatic asphaltenes is less thermally stable,the yield of nano-structures and nanofibers are higher compared to the asphaltenes from paraffinic oil,with trace metals remaining during the synthesis process.The carbon material from paraffin-naphthenic oil is amorphous with low heteroatoms content.
