Techniques of analysis of tar sand bitumens

The bitumen present in North American tar sand deposits is a heavy, viscous, petroleumlike material. Although several important studies of the composition of Athabasca tar sands were made 10-15 years ago (1-4) the bulk of our current knowledge of Utah and Athabasca bitumen has occurred within the last six years. Analysis to date has been largely limited to physical properties, elemental analysis, easily effected chromatographic separations and spectral analysis of the gross fractions derived. Detailed structural analysis comparable to that currently being achieved in high boiling distillates of petroleum (5, 6) and coal derived liquids (7) has not been accomplished; with tar sand bitumens. Analysis of the composition of tar sand bitumen is complicated predominantly by the high average molecular weight and wide distribution of heteroatoms present. The high average molecular weight results in a limited separation by distillation and in solutions which behave non-ideally¿. because of solute intermolecular associations. The wide distribution of heteroatoms results in amphoterism and significant overlap in adsorption or affinity chromatographic separation technique The presence of a multiplicity of hydrocarbon and non-hydrocarbon compound types adds difficulty^ to the interpretation data from chemical reactions. Despite these limitations, considerable information about the composition of tar sand bitumens is known. Additionally, there are many tecb/J niques and procedures developed in the course of petroleum analysis which have not been applied to tar sand bitumens. This paper is intended to provide a selected review of techniques which have been applied 1 compositional analysis of tar sands. These techniques include a discussion of the type of information obtained and limitations of the principal separation and spectral techniques. Where possible, projection is made of techniques likely to be useful but which have not been applied to bitumen analysis. Lastly, in keeping with the objectives of this symposium, a few observations are made regarding the nature of shale oil and coal derived liquids and the characteristics of these liquids important to the development of analytical techniques.