Properties Correlations and Characterization of Athabasca Oil Sands-derived Synthetic Crude Oil

Narrow fractions of Athabasca oil sands-derived synthetic crude oil （SCO） from Canada were obtained by distillation at 20 ℃ to 500 ℃ 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.

Characterization 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

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） tech- niques were used to characterize a low sulfur crude oil derived vacuum residuum （VR）. The appropriate CID operating condi- tion was selected by comparing the molecular weight distributions of the basic nitrogen compounds under various CID operat- ing conditions. Both odd- and even-electron fragment ions were observed from the mass spectrum, indicating that the hetero- lyric 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.

Thermal transformation of acid compounds in high TAN crude oil

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 02 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.

Effects of experimental conditions on the molecular composition of maltenes and asphaltenes derived from oilsands bitumen: Characterized by negative-ion ESI FT-ICR MS

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.