Shale distillates, hydrocarbon-type

The classical silica gel chromatographic method for determination of percent olefins in shale oils was studied and found wanting, mainly because of cross-contamination from high levels of olefins and heteroatom-containing compounds. This paper describes a new hydroboration/oxidation procedure for olefins, and reports its use in hydrocarbon-type analysis of both whole shale oils and distillate fractions. Percent composition values for three whole oils ranged as follows saturates, 13-26 olefins, 16-20 aromatics, 5-14 polar compounds, 41S2. A discussion of IR analysis for relative amounts of specific olefin types such as terminal, internal trans, and methylene structures is included. 

Work in the area of hydrocarbon-type analysis, i.e. saturate, olefin, and aromatic, has been conducted at the Laramie Energy Research Center (LERC) for over two decades. During this time, a significant portion of the eflFort has been directed towards the quantification and characterization of the various types of olefins found in Green River Formation shale oils and their distillate fractions (1-9). 

As with all shale oils, the polar material first must be removed from the oil prior to hydrocarbon-type analysis. The procedure shown in Figure 1 was applied several years ago to shale oil distillates in the boiling ranges 200°-325°C and 325°-S00°C (9). The technique made use of added internal standards and GC comparison of sample-internal... 

Table I. Hydrocarbon-Type Analysis of Shale Oil Distillates...

The classical silica gel olefin analysis was evaluated with respect to shale oil products and found wanting. A new approach to olefin analysis using mild, olefin-modifying reagents was described and partially demonstrated for shale oil distillates and whole oils. Hydrocarbon-type composition data and a discussion of IR analysis for various types of olefinic compounds were presented for three whole oils. 

Some specific class analyses have been reported for whole samples and distillates of shale oil and synthetic coal liquids (e.g.. References 1, 2, 3, and 4). A few examples of specific class analyses recently reported include determination of hydrocarbon types in shale oil distillates by a hydroboration technique (5), aromatic-aliphatic group analyses in petroleum and coal liquids (6), nitrogen base types in high-boiling petroleum distillates (7), and PAH fractions in oils (8,9). 

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