Bitumen chromatographic separation

Liquid Chromatographic Analyses. Analyses of about half the samples by the standardized method of liquid chromatographic separation are presented in Table IX. lii addition to asphaltenes and minerals, all contained large amounts of resins and small amounts of oils that are mostly hydrocarbons. Similar results were obtained whether the samples were analyzed as bitumens or as asphalts. In general, however, the bitumens gave somewhat more resins and hydrocarbons, whereas asphalts gave more asphaltenes. With Farukhabad 404, which was analyzed both as bitumen and as asphalt, the difference in asphaltenes was 8%. 

The oils and bitumen were separated chromatographically on silica gel into saturates, aromatics, polar aromatics, and asphaltenes fractions by the SAPA method of Barbour et al. (8). 

Chromatographic Separation Data for Bitumen and Product Oils... 

By chromatographic separation of the benzene soluble bitumen, followed by chemical separation of the methanol eluate, a fraction of weak acids was obtained. In this fraction, in addition to C---saturated unbranched monocarboxylic acids, saturated... 

Bitumens, were separated by chromatography, urea clathration and 5A molecular sieve occlusion before and after analyses of many of the aliphatic sub-fractions by GC and gas chromatography-mass spectrometry (GC-MS). Experimental details are noted in a previous publication (16) in which the distribution of cyclic alkanes in two lacustrine deposits of Devonian (N.E. Scotland) and Permian (Autun, France) age, (the D and C series samples) were discussed, Chromatographic separation into aliphatic, aromatic and polar compounds of the bitumens extracted from the shales gave the results shown in Table VI. Carbon Preference Indices and pristane/phytane ratios were measured in this work space limitations precluded... 

Sulfur compounds in the gas oil fractions from two bitumens (Athabasca oil sand and Cold Lake deposit)> a heavy oil (Lloydminster) from Cretaceous reservoirs along the western Canada sedimentary basin, and a Cretaceous oil from a deep reservoir that may be mature (Medicine River) are investigated. The gas oil distillates were separated to concentrates of different hydrocarbon types on a liquid adsorption chromatographic column. The aromatic hydrocarbon types with their associated sulfur compounds were resolved by gas chromatographic simulated distillation and then by gas solid chromatography. Some sulfur compounds were further characterized by mass spectrometry. The predominant sulfur compounds in these fractions are alkyl-substituted benzo- and dibenzothiophenes with short side chains which have few dominant isomers. 

Standardization of analytical techniques has helped greatly to compare asphalts of diflFerent areas and diflFerent periods. Repeated extractions with boiling toluene has improved consistency of data, whether or not it is the best way of separating bitumen and minerals. Liquid chromatographic analysis not only determines the amount of minerals suspended in the bitumen but also provides fractions suitable for further characterization. X-ray diffraction promises to improve vastly analysis of the minerals. No good way of resolving whatever usually small amounts of insoluble organic matter may be present has been devised. 

Wallace, D, Henry, D. Pongar, K. Zimmerman, D. (1987). Evaluation of Some Open Column Chromatographic Methods for Separation of Bitumen Components. Fuel, Vol.66, No.l, pp. 44-50... 

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