Abstract Asphaltene, from co-processing of coal and petroleum residues is one of the most precious and complex molecular mixtures existing, with tremendous economic relevance. Asphaltene was separated by Soxhlet extra...Abstract Asphaltene, from co-processing of coal and petroleum residues is one of the most precious and complex molecular mixtures existing, with tremendous economic relevance. Asphaltene was separated by Soxhlet extraction with methylbenzene and then divided into three parts by distillation. Gas chromatography （GC） and high-performance liquid chromatography （HPLC） were coupled with quadrupole time-of-flight mass spectrometry （Q-TOF MS） to separate and characterize organic nitrogen species in the distillates of asphaltene at molecular level. Molecular mass of compounds was mainly distributed from 150 to 600 ~t. Number of rings plus double bonds （rdb） and synchronous fluorescence spectra indicated that most of the organonitrogen compounds （NPAC） contained heterocyclic aromatic rings, including pyridines, anilines, quinolins, pyrroles, carbazoles and indoles plus various alkyl groups. Constant-wavelength synchronous fluo- rescence spectrometry （CWSFS） indicated NPAC with 2-3 rings were the main structures of organonitrogen compounds and the corresponding structural information was proposed. Some organic nitrogen isomers were separated and identified by atmospheric pressure chemical ionization （APCI） GC-Q-TOF MS and electrospray ionization （ESI） HPLC-Q-TOF MS. The methodology applied here contained chromatographic injection of the diluted sample using conventional columns sets and Data Analysis 4.2 software. Identifying molecular structures provides a foundation to understand all aspects of coal- derived asphaltene, enabling a first-principles approach to optimize resource utilization.展开更多
Glass-ceramics obtained from the electric arc furnace molten slag of incinerator fly ash was produced by applying nucleation and crystallization through heat treatment process. The effects of nucleating agent （TiO2 a...Glass-ceramics obtained from the electric arc furnace molten slag of incinerator fly ash was produced by applying nucleation and crystallization through heat treatment process. The effects of nucleating agent （TiO2 and Cr2O3） on the crystallization kinetics and heat treatment schedule of the slag were investigated. The results show that the nucleating agents changed the crystallization phase and morphology of the obtained glass-ceramics. The optimum heat treatment schedule of the glass with TiO2 was determined as nucleation at 952 K for 1.5 h and crystal growth at 1 258 K for 1.5 h, while those values with Cr203 were estimated at 971 K for 2 h and at 1 238 K for 2 h. TiO2 acting as nucleating agent could decrease the activation energy of the slag and shorten the total thermal treatment time in comparison with Cr2O3. The glass-ceramics obtained under the optimum heat treatment condition was environmentfriendly and had remarkable physical/mechanical properties and chemical durability.展开更多
基金Acknowledgements The authors gratefully acknowledge the financial support of this work by the National Natural Science Foundation of China （No. U1510122）. The authors declare that the experiments comply with the current laws of China.
文摘Abstract Asphaltene, from co-processing of coal and petroleum residues is one of the most precious and complex molecular mixtures existing, with tremendous economic relevance. Asphaltene was separated by Soxhlet extraction with methylbenzene and then divided into three parts by distillation. Gas chromatography （GC） and high-performance liquid chromatography （HPLC） were coupled with quadrupole time-of-flight mass spectrometry （Q-TOF MS） to separate and characterize organic nitrogen species in the distillates of asphaltene at molecular level. Molecular mass of compounds was mainly distributed from 150 to 600 ~t. Number of rings plus double bonds （rdb） and synchronous fluorescence spectra indicated that most of the organonitrogen compounds （NPAC） contained heterocyclic aromatic rings, including pyridines, anilines, quinolins, pyrroles, carbazoles and indoles plus various alkyl groups. Constant-wavelength synchronous fluo- rescence spectrometry （CWSFS） indicated NPAC with 2-3 rings were the main structures of organonitrogen compounds and the corresponding structural information was proposed. Some organic nitrogen isomers were separated and identified by atmospheric pressure chemical ionization （APCI） GC-Q-TOF MS and electrospray ionization （ESI） HPLC-Q-TOF MS. The methodology applied here contained chromatographic injection of the diluted sample using conventional columns sets and Data Analysis 4.2 software. Identifying molecular structures provides a foundation to understand all aspects of coal- derived asphaltene, enabling a first-principles approach to optimize resource utilization.
基金Supported by the National Natural Science Foundation of China(No.51378332 and No.20806051)Science and Technology Project of Housing and Urban-Rural Ministry(No.2014-K4-014)Chinese Postdoctoral Science Foundation(No.2013M530872)
文摘Glass-ceramics obtained from the electric arc furnace molten slag of incinerator fly ash was produced by applying nucleation and crystallization through heat treatment process. The effects of nucleating agent （TiO2 and Cr2O3） on the crystallization kinetics and heat treatment schedule of the slag were investigated. The results show that the nucleating agents changed the crystallization phase and morphology of the obtained glass-ceramics. The optimum heat treatment schedule of the glass with TiO2 was determined as nucleation at 952 K for 1.5 h and crystal growth at 1 258 K for 1.5 h, while those values with Cr203 were estimated at 971 K for 2 h and at 1 238 K for 2 h. TiO2 acting as nucleating agent could decrease the activation energy of the slag and shorten the total thermal treatment time in comparison with Cr2O3. The glass-ceramics obtained under the optimum heat treatment condition was environmentfriendly and had remarkable physical/mechanical properties and chemical durability.
