Shale oil, crude

Table 10. Comparison of Green River Crude Shale Oil and Median U.S. Crude ...

H. Batrick and co-workers. Final Report—The Production and Refining of Crude Shale Oil into Military Fuels, AppHed Systems Corp. for Office of Naval Research, Washington, D.C., Aug. 1975. 

Poulson, R.E. Frost, C.M. Jensen, H.B. Characteristics of Synthetic Crude from Crude Shale Oil Produced by In-situ Combustion Retorting, In Shale Oil, Tar Sands, and Related Fuel Sources Yen, T.F., Ed ACS Adv. Chem. Ser. No. 151, 1976, 1. 

We will examine three synthetic fuel scenarios and compare their implications regarding sulfur availability with the current and projected market for sulfur to the year 2000. The analysis will consider three production levels of synthetic fuels from coal and oil shale. A low sulfur Western coal will be utilized as a feedstock for indirect liquefaction producing both synthetic natural gas and refined liquid fuels. A high sulfur Eastern coal will be converted to naphtha and syncrude via the H-Coal direct liquefaction process. Standard retorting of a Colorado shale, followed by refining of the crude shale oil, will round out the analysis. Insights will be developed from the displacement of imported oil by synthetic liquid fuels from coal and shale. 

Characteristics of Synthetic Crude from Crude Shale Oil Produced by in Situ Combustion Retorting... 

A further chracterization of these pyrrole type nitrogen compounds in the very weak base concentrate can be made by using the colorometric pyrrolic nitrogen value of 6.8% (Table III) as the value for a, -unsub-stituted pyrrole type compounds. This leaves 22.2% of the nitrogen in pyrroles and indoles which have both a- and -substitution. The affi-unsubstituted pyrroles and indoles also have no N-substitution because these N-substituted compounds would titrate as weak bases and not as very weak bases. The lack of N-substitution on the pyrroles and indoles is consistent with the research of Jacobson (18, 19) who reported that N-alkylpyrroles and N-alkylindoles thermally and irreversibly isomerize to give the a and alkyl isomers and therefore would not likely be present in crude shale oil. 

The synthetic crude was produced by hydrogenating the IBP-350°F naphtha, the 350°-550°F light oil, and the 550°-850°F heavy oil fractions obtained from in situ crude shale oil by distillation followed by coking of the 850°F-f- residuum. Characterization of the syncrude was accomplished by examining the following fractions CB-175°F light naphtha, 175°-350°F heavy naphtha, 350°-550°F light oil, and 550°-850°F heavy oil. 

The crude shale oil used in this study was obtained from an in situ combustion retorting experiment at Rock Springs, Wyo. (I, 2), during the last week of the experiment and is considered a representative steady state oil. Properties of the in situ crude shale oil are shown in Table I. 

Charge stock for the catalyst testing experiment was prepared by topping a sample of the in situ crude shale oil to 600°F in a batch still equipped with a column having 35 trays and then separating the 600°— 1000°F fraction in a vacuum flash distillation unit. Properties of the 600°-1,000°F fraction of in situ crude shale oil are shown in Table III. 

Table III. Properties of 600°—1000°F Distillate from in Situ Crude Shale Oil...

Preparation of Synthetic Crude. The overall flow diagram for upgrading crude shale oil is shown in Figure 5. A sample of in situ crude... 

Figure 5. Flow diagram for upgrading in situ crude shale oil...

The 175°-350°F naphthas from the two previous hydrogenation runs were combined with the total naphtha from the third distillation of in situ crude shale oil and coker distillate. The combined naphthas were then hydrogenated in a continuous 48-hr run. Operating conditions and product yields are shown in Table VIII. Under the conditions used, only 4.3 wt % of the charge was converted to products boiling below 175°F. 

In Table X the properties of the syncrude prepared from in situ crude shale oil are compared with the properties of a syncrude listed by the NPC. Relative amounts and properties of the naphthas, light oils, and heavy oils are also compared. These data show that the nitrogen content, sulfur content, pour point, viscosity, and API gravity of syncrude prepared from in situ crude shale oil are lower than those suggested in... 

A summary of the yields from the various steps used in the preparation of syncrude from in situ crude shale oil is shown in Table XI. The overall yield of syncrude was 103 vol % of the original crude. 

Hydrogenation tests made on the 600°-1000°F heavy gas oil from in situ crude shale oil showed that a nickel-molybdenum-on-ahimina catalyst was superior to either cobalt-molybdenum-on-alumina or nickel-tungsten-on-alumina catalysts for removing nitrpgen from shale oil fractions. This nickel-molybdenum-on-alumina catalyst was used in the preparation of the synthetic crude oil. A high yield of premium refinery feedstock whose properties compared favorably with those of a syncrude described by the NPC was attained by hydrogenating the naphtha, light... 

TABLE I. - Hydrocracking of in situ crude shale oil over nickel-molybdena catalyst... 

Crude shale oil is an important potential source of transportation fuels when properly refined. However, although it is low in sulfur compared with mid-East crudes, it is much higher in nitrogen than typical petroleum crudes. The shale oil used in this study contains 2.2 wt % nitrogen typical petroleum crudes contain less than 0.3% nitrogen. 

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