Pyrolysis of shale oil vacuum distillate fractions

The freezing point of U.S. Navy jet fuel (JP-5) has been related to the amounts of large nalkanes present in the fuel. This behavior applies to jet fuels derived from alternate fossil fuel resources, such as shale oil, coal, and tar sands, as well as those derived from petroleum. In general, jet fuels from shale oil have the highest and those from coal the lowest n-alkane content. The origin of these n-alkanes in the amounts observed, especially in shale-derived fuels, is not readily explained on the basis of literature information. Studies of the processes, particularly the ones involving thermal stress, used to produce these fuels are needed to define how th n-alkanes form from larger molecules. The information developed will significantly contribute to the selection of processes and refining techniques for future fuel production from shale oil. Carbon-13 nmr studies indicate that oil shale rock contains many long unbranched straight chain hydrocarbon groups. The shale oil derived from the rock also gives indication of considerable straight chain material with large peaks at 14, 23, 30 and 32 ppm in the C-13 nmr spectrum. Previous pyrolysis studies stressed fractions of shale crude oil residua, measured the yields of JP-5, and determinedmore » the content of potential n-alkanes in the JP-5 distillation range (4). In this work, a shale crude oil vacuum distillate (Paraho) was separated into three chemical fractions. The fractions were then subjected to nmr analysis to estimate the potential for n-alkane production and to pyrolysis studies to determine an experimental n-alkane yield.« less