The large oil shale deposits in the United States virtually assure the place of shale oil as an unconventional fuel source to meet future transportation needs. It is important to understand the impact of unconventional hydrocarbon streams on fuel properties by examining differences in average chemical structures for these fuels before and after various upgrading methods have been applied.  We have utilized 1H and 13C NMR spectroscopy to examine the changing chemical structure distribution of a shale oil at several stages of processing, from extracted shale oil to finished diesel fuels. Unprocessed shale oil from the Uinta Basin in Utah was obtained from Red Leaf Resources, Inc., and was processed using catalytic hydrotreatment and distillation to provide raw, partially, and fully treated shale oil for analysis and property comparison. Mild hydrotreating of the EcoShale feedstock resulted in relatively consistent levels of heteroatom-containing species, while more rigorous hydrotreating to attain the finished fuel considerably reduced these species. Stabilization and hydrotreating also resulted in a considerable reduction in olefin content, which were confirmed by a reduction in bromine number (ASTM D1149).  Additionally, the finished Diesel #2 was found to have a higher quantity of fused-ring aromatics and a longer average n-paraffinic chain length than the Diesel #1 sample. The functional group distributions found in the finished Diesel #1 and #2 samples compare favorably with those found for equivalent commercial diesel fuels. Our NMR analyses are consistent with the expected changes in molecular structure compositions as diesel fuels are produced from an untreated shale oil feedstock and can provide actionable data such as a means of providing input when combining blending streams.

<sup>1</sup>H and <sup>13</sup>C NMR characterization of oil shale crude at various process stages of distillate fuel production

248th National Meeting (2014)

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1H and 13C NMR characterization of oil shale crude at various process stages of distillate fuel production

¹H and ¹³C NMR characterization of oil shale crude at various process stages of distillate fuel production