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6篇 您的检索式:作者名="Keng H. Chung"
    题名 作者 年代 出处 被引量
1Characterization of heavy petroleum fraction by positive-ion electrospray ionization FT-ICR mass spectrometry and collision induced dissociation: Bond dissociation behavior and aromatic ring architecture of basic nitrogen compounds显示文摘This paper examined the bond dissociation behavior and aromatic ring architecture of basic nitrogen compounds in Sudan heavy petroleum fraction. Both broadband and quadrupole isolation modes positive-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) coupled with collision induced dissociation (CID) techniques were used to characterize a low sulfur crude oil derived vacuum residuum (VR). The appropriate CID operating condition was selected by comparing the molecular weight distributions of the basic nitrogen compounds under various CID operating conditions. Both oddand even-electron fragment ions were observed from the mass spectrum, indicating that the heterolytic and homolytic bond cleavages occurred simultaneously during the CID process. The odd-electron fragment ions were predominant in each class species, indicating preferential heterolytic bond cleavages. At the optimal CID condition, the alkyl groups decomposed deeply and just left the aromatic cores of the nitrogen compounds. No significant variation in double bond equivalent (DBE) value was observed between the fragment and parent ions, revealing that the domination of single core structure.ZHANG LinZhou ZHANG YaHe ZHAO SuoQi XU ChunMing CHUNG Keng H. SHI Quan 2013Science China Chemistry2013,56,7:5
2Thermal transformation of acid compounds in high TAN crude oil显示文摘The Liaohe crude oil with high total acid number (TAN) was subjected to thermal reaction at 300℃to 500℃. Reaction products were collected and analyzed by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) to determine acid compounds in the crude oil. The double-bond equivalence (DBE) versus carbon number was used to characterize the oxygenated components in the feed and reaction products. The O2 class which mainly corresponds to naphthenic acids decarboxylated at 350-400℃, resulting in a sharply decrease in TAN. Phenols (O1 class) are more thermally stable than carboxylic acids. Carboxylic acids were also thermally cracked into smaller molecular size acids, evidenced by the presence of acetic acid, propanoic acid, and butyric acid in the liquid product. These small acid species are strong acids likely responsible for corrosion problems in refineries.YANG BaiBing XU ChunMing ZHAO SuoQi HSU Chang Samuel CHUNG Keng H. SHI Quan 2013Science China Chemistry2013,56,7:3
3Effects of experimental conditions on the molecular composition of maltenes and asphaltenes derived from oilsands bitumen: Characterized by negative-ion ESI FT-ICR MS显示文摘A vacuum topped Canadian oilsands bitumen (VTB) was subjected to solvent precipitation and subsequently characterized by elemental analysis, gel permeation chromatograph (GPC), 1 H-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-C5 , 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 composition of asphaltenes varies with separation conditions. The N1 and O1 species identified by ESI FT-ICR MS were enriched in maltenes. The O2 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 asphaltenes. Compound class distributions are similar for maltenes derived from n-C5 , 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 molecular composition. A portion of neutral N1 species and acidic O2 species adsorbed on asphaltenes could be dissolved by increasing washing time. Cautions should be exercised when interpreting the properties and composition of asphaltenes obtained with different experimental conditions.WANG LiTao HE Chen LIU Yang ZHAO SuoQi ZHANG YaHe XU ChunMing CHUNG Keng H. SHI Quan 2013Science China Chemistry2013,56,7:2
4Properties Correlations and Characterization of Athabasca Oil Sands-derived Synthetic Crude Oil显示文摘Narrow fractions of Athabasca oil sands-derived synthetic crude oil (SCO) from Canada were obtained by distillation at 20 oC to 500 oC and characterized. The yield and properties, such as density, refractive index, viscosity, freezing point, sulfur and nitrogen content and UOP K-index, were correlated as a function of boiling temperature (Tb). The properties of naphtha fractions, jet fuel and diesel fractions could be predicted accurately with the correlations, which are useful for process design considerations, such as optimizing operating conditions of refinery processing units. The other key properties and characteristics of naphtha fractions, jet fuel, diesel and vacuum gas oil were also determined.Wang Jun Zhao Suoqi Xu Chunming Chung Keng H. 2007Petroleum Science2007,4,3:1
5Petroleum heteroatom compounds in various commercial delayed coking liquids: characterized by FT-ICR MS and GC techniques显示文摘Delayed coking is an important petroleum resid conversion process.The processability of coking liquids is known to be dependent on the heteroatom compounds present in the coking liquids.Eight commercial delayed coking liquids were characterized by electrospray ionization(ESI)Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS)and gas chromatographic techniques.High relatively abundant heteroatom compounds in the coking liquids were 1-4 aromatic-ring pyridinic nitrogen compounds,carbazoles,benzocarbazoles,phenols,mercaptans,benzothiophenes,dibenzothiophenes,and naphthobenzothiophenes.Coking liquids derived from various feeds had similar compound class types,molecular weight distribution ranges,and double bond equivalents(DBE).However,the concentration of individual compounds and the distribution of DBE versus carbon number of heteroatom compounds varied.A comparison of heteroatom compounds in coker feeds and products revealed the various reaction mechanism of heteroatom compounds occurred during the coking process.The results suggested that molecular-level process models can be developed for optimization of unit operation to obtain desirable products that meet the environmental specifications and quality requirements.Miao Hu Chuang Guo Linzhou Zhang Suoqi Zhao Keng H. Chung Chunming Xu Quan Shi 2017Science China Chemistry2017,60,2:1
6Preface显示文摘The petroleum industry comprises extensive production operations which produce 5.5 billion tons a year of petro- leum feedstocks which are transformed into thousands of consumer products. This industry is constantly faced with many scientific and technical challenges related to improv- ing operational efficiency, meeting the growing demand and complying with more stringent environmental legislations.Chunming Xu Keng H. Chung 2013Science China Chemistry2013,56,7:0
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