Chemical composition of Athabasca bitumen

A detailed analysis has been carried out on the deasphaltened Athabasca bitumen using two different series of Chromatographic separations followed by i.r., u.v., n.m.r. and computerized GC/MS studies of the separated fractions: saturates (22–25%), monoaromatics (10.3–10.8%), diaromatics (4.6–5.3%), polyaromatics and non-specific polar compounds (28.6%), acids (16.5%), bases (7.8%), and neutral nitrogen compounds (1.6%). The acyclic paraffin content of the maltene is low: straight-chain paraffins and the isoprenoids, phytane and pristane, are present in very low concentrations. Polycyclic saturates represent about 90% of the saturate fraction. The presence of C-27 and C-29–C-35 hopanes of the 17(h):21β(H) series and C-21–C-30 steranes was established. The mono- and diaromatic fractions were analysed by computerized mass spectrometry. The monoaromatic fraction contains alkylbenzenes, naphthenebenzenes and dinaphthenebenzenes in a ratio of 1.0:1.7:1.3. The ratio for naphthalenes, acenaphthenes + dibenzofurans and fluorenes in the diaromatic fraction is 1:0.9:0.5.