CA1180296A - Method for treating shale oil and producing liquid transport fuel therefrom - Google Patents

Abstract

Abstract The nitrogen content of shale oil is reduced by catalytic cracking and contacting the oil with an aqueous solution of phosphoric acid. The treated shale oil can be further processed to obtain a combustion fuel such as diesel fuel, gasoline and turbine fuel.

Description

Desc~

Technical Field The present invention is concerned wi-th a me-thod for reducing the ni-trogen content of shale oil and is par-ticularly concerned with 5 a combina-tion of catalytic cracking and extraction to achieve this purpose . In addi-tion, the present inven tion is concerned wi-th employing the shale oil of reduced nitrogen content -to produce a combustion fuel such as diesel fuel, gasoline and turbine fuel.

Background Art In view of the significant price increases in petroleum oils in the last few years along with the con-tinuing increased demands for energy, renewed attention has been focused on -the recovery of oil from oil shale and the subsequent conversion of the oil -to usable, valuable, combustible products.

A number of differences exis-t between petroleum oils and oils derived from oil shale. One significant difference is -the amount of nitrogen present in the oil. Mos-t petroleum oils con-tain a-t most about 0 . 05% by weight of nitrogen, whereas shale oils generally contain at least about 0 . 5% and mainly a-t least abou-t 1% by weight 20 of nitrogen. These quantities of nitrogen if not siynificantly reduced prior to such processes as catalytic reforming can cause significant problems. The ni-trogen tends to poison and/or reduce catalyst activity used in such processes. In addi tion, the burning of oils con taining such high quan-ti ties of 5 nitrogen is a problem from an ecological viewpoin-t, since the burning produced nitrous oxide. Only very restricted amounts of ni-trous oxide are permi-t-ted to be exhaus ted into -the atmosphere .
Fur thermore, the presence of nitrogen in the finished fuel is undesirable since nitrogen compounds ~end to cause thermal 10 instability of the finished fuel.

One method employed to reduce the nitrogen conten-t of shale oil has been -to s ubject the shale oil to hydrotreating using a catalyst. However, such processes in order to remove significant quantities of ni-trogen have required relatively high hydrogen 15 consumpti~ns such as up to 3000 standard cubic feet per barrel (SCF/B) and generally at least about 1200 SCF/B and extremely high temperatures and pressures. Accordingly, such processes have been quite expensive to implement in view of the types o:E
special equipment needed to withstand the -temperature and pressure 20 conditions found necessary and in view of the amount of energy and cost needed to provide the needed hydrogen.

The use of various acids to ex-trac-t ni trogen compounds from shale oil has been sugges-ted, bu-t the previous suggested , processes have not been especially successful. This is due at leas-t in part to -the fac t that, not all of the nitrogen compounds as iniiially con-tained in the shale oil are considered basic nitrogen compounds or are extractable with mineral acids, and particularly, 5 all are not extrac-table with the acid employed according to -the present invention. For instance, See Chemical Abs-trac-ts, Vol.
751~3(d) which describes at leas t three classes o:E nitrogen compounds which are recognized as being contained in crude shale oil. Besides basic nitrogen compounds which are extractable with 10 weak acids, crude shale oil contains in varying amounts nitrogen compounds which are insoluble in weak acids, and which are polymerized by strong acids; and compounds which are stable to concen-trated sulfuric acid and are not extracted thereby.
Accordingly, processes have heen suggested employing certain acids 15 in combination with other trea-ting steps and employing certain acids to the exclusion of others.

For ins-tance, U.S. Patent 2,692,226 to Smith suggests treating shale oil by hydrogena tion with a hydrogenation catalyst composed of mixed sulphide of nickel and tungsten or nickel and molybdenum.
20 The hydrogenation employed is relatively severe compared -to -the initial hydrogenation process employed according to a preferred aspect of the present invention. The l?~j hydrogenation as sugges-ted by Smith resul-ts in a substan tial removal of the nitrogen content of -the oil as illustra-ted in the -table on column 3 thereof . Smi-th fur ther sugges-ts trea ting -the hydrotreated rna-terial to improve its color by a mild acid trea-tment 5 with sulfuric acid and also alludes to the possible use of other aclds such as phosphoric acid. The examples employ sulfuric acid. The hydro-trea-ting s-tep suggested by Smith should be severe enough so as to saturate aroma-tics and olefins -to preven-t -the loss in yield discussed therein. Sulfuric acid tends -to cause polymerization of 10 the olefins and -to remove the aroma-tics along with ni-trogen compounds. Accordingly, Smith seems -to suggest tha-t a large por-tion of the nitrogen could not be removed by the acid trea-tment without a great loss in yield. Nowhere does Smigh suggest any preference for phosphoric acid, and in fact, the use of sulfuric 15 acid therein tends to sugges-t a preference for sulfuric rather-than phosphoric acid. Moreover, Smith does not indicate -that the use of phosphoric acid would provide differen-t results than sulfuric acid as is achieved by -the present inven-tion.

U. S. Patent 3,085,061 to Metrailer suggests a process for 20 refining shale oil which includes a mild hydrotreatmen-t to remove sulfur followed by treatmen-t with anhydrous hydrogen chloride to form a sludge containing substantially all of -the nitrogen.

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Metrailer fur-ther sugges-ts -tha-t solven-ts previously employed in shale oil refining which removed undesirable nitrogenous materials were unselective and removed desirable cracking constituen-ts as well. Accordingly, -Metrailer requires the use of anhydrous 5 hydrogen chloride. Metrailer would tend to lead persons skilled in -the art away from the presen-t invention since among o-ther things it would be contrary to -the sugges tions of Metrailer to employ an aqueous phosphoric acid system.

Besides Me-trailer, -there exis ts a number of o-ther prior ar-t 10 patents which would tend to lead persons skilled in the art away from the acid employed according to -the present invention. For instance, U.S. Patent 3,309,324 to McAllister et al suggests -the use of certain weak acids to extract nitrogenous compounds from various oils. Mc~llister et al suggest that the use of strong mineral acids 15 such as sulfuric acid and hydrochloric acid results in certain disadvantages. These disadvan-tages suggested by McAllister et al include the tendency of the strong acids to polymerize unsaturated hydrocarbons which are frequently presen-t in petroleum distillates, and to extract constituen-ts which because of their anti-knock 20 prospects are more advantageously left in -for motor fuels. The presen-t inven-tion does not suffer iErom -these disadvantayes.

U.S. Patent 2,966,a~50 to Kemberlin, Jr. et al Rl-6002A

sugges-ts a process for re Eining shale oil which includes using a selective solvent and anhydrous hydrogen chloride. Kemberlin, Jr.
et al suggests tha-t solvents previously employed in shale oil refLling, includiny s Erong acids such as sul:Euric acids and weak 5 acids such as sulfurous acid gave unsatisfactory results, either because of inef-fec-tiveness or poor selectivity ~e . g ., resul-ting in removal of desirable cracking cons tituen ts along with the nitrogenous material).

U. S. Patent 2,662,843 to Castner et al suggest a process for 10 refining shale oil which includes using formic acid preferably af-ter a mild thermal cracking . Castner et al further sugges ts that solvents previously employed in general were not sufficiently selective and removed desirable substances such as aromatics.

U.S. Patent 2,541,458 to Berg suggests aqueous solutions of 15 various volatile acids or salts of non-volatile acids to recover nitrogen bases from shale oil but does not specifically sugges t employing non-volatile acids such as the acids required by the techni~ue of the present invention, and does not suggest cracking prior to extraction.

U . S . Patent 2,518,353 to McKinnis sugges ~s removal of ni-troçlen compounds from oils including shale oil and shale oil fractions with an extractant containing acid ammonium or amino or salts of strong non-volatile acids, I~I- 6002A
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r !~6 such as salts of phosphoric acid. The examples of said pa-ten-t sugges-t mixtures of free phosphoric acid with the required extractant compounds. However, this pa-tent would actually -tend -to lead persons skilled in the art away from the present invention 5 since among other things there is no sugges-tion in -this pa-tent -to employ a cataly-tic cracking step prior to the extraction of the nitrogen compounds as required by the presen-t invention in order -to achieve the results obtained herein.

The discussion in Chemical Abstracts 44-7518(d) suggests the 10 removal of certain ni-trogen compounds from shale oil employing dilute mineral acids. However, such does not even remo-tely suggest the importance of employing a catalytic cracking s-tep prior to extraction with -the acid as required by -the present invention.

U.S. Paten-t 3,123,550 -to Skomoroski et al sugges-ts mixing a 15 shale oil distillate with an acid such as phosphoric acid, and then hydrotrea-ting the mixture. The acid is sugges-ted as aiding in increasing the catalyst surface available Eor hydrogen adsorption (see column 1, lines 49-61 for instance~.

U . S . Pa-tent 2, 035, 583 to Bailey sugges-ts a process for 20 separating and purifying nitrogen bases which includes use of various acids. However, there is no disclosure of -the acid employed according -to the present invention.
U.S. Patent 2,084,617 to Chellis et al is concerned with reducing nitrogen content of naphthas prior to reforming.
Chellis e t al suggest mild hydrotreating followed by -treatment with sulfuric acid for certain naphthas as well as treatment with sulfuric acid followed by mild- hydrotreating followed by another treatment 5 with sulfuric acid, which latter process is preferred by Chellis et al for shale oil naphthas.

U.S. Patent 2,800,427 to Junk, Jr. et al suggests pretreating hydrocarbon oils prior to catalytic cracking with a non-oxidi2ing acid such as sulfuric acid and hydrochloric acid.

U.S. Patent 2,925,381 to Fleck et al suggests removing organic nitrogen compounds from hydrocarbons such as shale oil hy using a zeolite .

The object of this inven-tion is to maximize the production of jet fuel, particularly military jet fuel, from shale oil at lowest cost and minimum consurnp tion of hydrogen . Jet fuels suitable for military use have a number of specific properties which must be met. A series of complex processing operations are required to achieve the desired properties. A further object of this invention is to maximize the yield of jet fuel from shale oil by developing a process which facilitates the production of a much broader boiliny point fuel. Certain jet fuels have a very low initial boiling point with an end point specified in the range of 350F to 450F. Other jet fuels have a higher initial boiling point with an end point boiling in the range of 550F or greater. In the process of this invention we cut the initial hydrotreated product at 500F to 650F in g order to provide as much je-t fuel as possible, particularly specific jet fuels such as JP-~L and JP-8, -to yield an even grea-ter amount of jet Euel per barrel of shale oil processed. Obviously, such a broad range s tock is extremely desirable during periods of military 5 emergency and/or war . The process of this inven tion accordingly is one in which all these fac-~ors have been considered and uniquely combined so as to provide a process meeting the above objectives, in -terms of capi tal investment, operating cos-ts and yield of desirable product.

Description of Invention A general description of the process of this invention is as follows .

Crude shale oil containing a considerable amount of sediment fines, materials such as iron, iron sulfides and so forth, and other 15 material which would tend to plug a catalyst bed, and arsenic, which is a poison for hydrotreating catalysts and other catalysts in -the process, as well as other materials such as iron, iron sulfides and so forth, are first removed from the feedstock by passing it through a bed of adsorbent of high surface area in the presence of 20 hydrogen. Two or more of these beds can be operated in parallel and in a swing fashion so that one bed can be used while the other is being reconditioned. The effluent produc-t from this hydrocleaning operation is then passed through a bed of cobalt- or nickel- moly or o-ther suitable hydrotreating ca talyst in order to 25 remove sulfur, oxygen, and remaining metals and a small amount of nitrogen. ~Iore importantly, this step greatly minimizes hydrogen consumption by converting most of the nitrogen compounds to basic nitrogen compounds. The purpose of this operation is to condition the nitrogen compound~ without consuming hydrogen so that they may be properly extracted in an acid extraction process. This is one of the unique features o~ t~is process. The product from this mild hydrotreating operation is then distilled to obtain and remove a light fraction boiling in the desired range.
The bottoms from this distillation is sent to catalytic cracking. While nitrogen per se is usually considered an undesirable component in feesstock for catalytic cracking, the operation of the catalytic cracking in this process is minimized.
- In the subsequent cracking operation sev~ral objectives are kept in mind. First of all, the catalytic cracking operation is carried out under such conditions that we minimize the production of light ends, gasoline, or other low boiling hydrocarbons is minimized. The objective is to cascade the material boiling above 650 F to a material boiling below 650 F or some other endpoint commensuxate with the desired jet fuel. For example, if it is sought to maximize the production of JP-4, the cut taken orf in distillation of the hydrotreated product might be in the neighborhood of 450 - 500 F, and the bottoms going to the catalytic cracker would have an lnitial boiling point in the range of 450 - 500 F. On the other hand, if JP-8 ,is to be produced the distillation column is operated so that the higher boiling range described herein would be utilized. The product from catalytic cracklng ls next ,,, ., ... ... ... , , . . .

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sent to acid extraction along with the overhead from the hydrotreated product. The product obtained is one boiling in the broad range desirable for jet fuel but still containing 8 considerable amount of nitrogen, sulfur, and oxygen compounds and olefins. This product also contains amounts of normal paraffins sufficient to deleteriously affect the freeze point of jet fuel. The bot~oms from catalytic cracking of the hydrotreated 650 shale oil fraction become ~oo refractory for further cataly~ic cracking. In order to maximize production of jet fuel, these refracting bo~toms are sent to a separate hydrotrea~ing step where hydrogen is added and are returned to the catalytic cracker. The overhead, both from catalytic cracking and from hydro-treating are then sent to an acld extraction process util-izing phosphoric acid. Phosphoric acid is superior inthis regard since it avoids problems of undesirable corrosion encountered with hydrochloric acid and formation of the sulfonates if sulfuric acid i5 used. Thi process also produces ammonia, which can be used to spring the phcs-phoric acid extract free from the nitrogen-containing compounds, thus producing ammonium phosphate. The process thus provides the additional advantage of producing ammonium phosphate which can be used as a fertilizer. A useful produc~ is thus produced rather than a waste product, as would be in utilizing either hydrochloric acid or sulfuric acid.
The produc~ from the phosphoric acid extraction con-stitute~ a hydrocarbon product bolling in the desirable range but still containing sulfur, nitrogen, olefins, a -:L2-small amount of arsenic, and paraffins. It is hydrotrea-ted in order to remove these impurities and to prepare a feeds-tock for a reforming opera-tion at somewhat unique conditions so as to bring abollt the hydrocycliza-tion, isomerization and hydrocracking, 5 particularly of the normal paraffins to produce a produc-t which is accep-table in all respects for jet fuel wi-th -the excep-tion that in -the reforming step aromatic conten-t may be increased above -the maximum allowed in military jet fuel. For this reason, then, there is finally added a polishing and distillation step which is used to 10 reduce the aromatic content to an acceptable level.

Brief Description of Drawing The drawing is a schematic diagram of a sequence of steps suitable for preparing combustion fuels such as gasoline, diesel fuel and aviation turbine fuel, from shale oil in accordance with the 15 present invention.

Best and Various Modes for Carrying Out the Invention The shale oil, which can be treated according -to the present invention, can be any shale oil material and/or distillate thereof and generally contains more than about 0.1% by weight and usually at 20 least about 0.5% by weight of nitrogen compounds.

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The shale oil material treated p-ursuan-t -to the presen t invention typically boil a-t abou-t 100F -to about 1200f.

Reference to the figure will help to illustrate the presen-t invention. According to a preferred embodimen-t, the raw or crude 5 shale oil is subjected to an ini-tial relatively mild hydro-trea-ting process designated as 1. The to-tal hydrogen consump-tion of the relatively mild hydrotreating is generally up i;o about 1200 SCF/B of oil . The minimum hydrogen consumption is tha t amount needed to substantially saturate the non-benzenoid unsa-turated ma-terials such 10 as the olefins and diolefins in the oil and to increase the yield o:E
basic nitrogen compounds and is generally at least about 50 SCF/B.

The initial mild hydrotreatmen t step is provided to remove at least a subs-tantial amoun t, if not all, of the sulfur and/or arsenic present in the shale oil. As discussed hereinabove, the shale oil 15 con-tains nitrogen compounds which are not extractable with aqueous phosphoric acid. However, it has been observed that this initial hydrotreating s-tep, although not removing a significant quantity of nitrogen compounds, increases the ratio of basic nitrogen to to-tal nitrogen remaining in the oil. This hydrotreatment resul-ts in the 20 removal of some nitrogen in some form and could be removal of non-basic nitrogen compounds and/or basic nitrogen compounds. It has been no-ted tha-t the basic nitrogen compounds are generally thought of as being more readily ~I - 6002A

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removable by hydro-trea-ting -than are -the non-basic ni trogen compounds. In addi-tion, -this hydrotreating step is designed to cause conversion of nitrogen materials which are not extractable wi-th phosphoric acids in-to basic nitrogen ma-terials which are extractable with a(lueous phosphoric acids. This mild hydrotreating removes a-t most abou-t 30% by weigh-t and generally a t most about 15% by weigh-t of -the nitrogen initially present in the oil.

The ability to employ a relatively mild hydrotreatmen-t is quite advantageous from an economic viewpoin t in -that ~he cost of equipment and amount of energy for the needed hydrogen for such hydrotreatment can be reduced as compared to the costs employed in carrying ou-t more severe hydrotreatments. This hydrotreatment is also advantageous since the nitrogen content is reduced -to some exten-t which in turn lessens any possible detrimental effect of nitrogen on the cracking ca talys t . Moreover, it is believed tha t such hydrotrea-ting pr ovides ni trogen compounds which are less refractory and reduces the overall viscosi ty of the rnaterial fed to the ca talytic cracking .

The general conditions for this mild hydrotreating in addition to the hydrogen consumption discussed hereinabove ~ include inle t temperatures of about 350 to about 750F, preferably about 600 to about 700F; and most preferably abou-t 625 to about 675F;
pressure of abou-t 300 to about 2000 psig, preferably up to about 1600 psig, and most preferably about 1000 psig and liquid hourly space velocities of about 0.5 to about 10, and preferably about 2 -to about 3 at the preferred pressures. In addition, hydrotreating catalysts such as cobalt-molybda te and/or nickel molybdate can be used when desired. The catalyst can be supported on a carrier such as alumina. Examples of some hydrogenation catalysts can be found in U . S . Patent 3, 029, 230 to 5 MacLaren, The preferred catalyst employed is cobalt-molybdate on alumina support such as Nalcomo 477 available Erom Nalco Chemical Company which according to the manufacturer contains on a dry weight basis about 14 . 0% MoO3, and about 3 . 83% CoO and the balance alumina .
10 Some typical physical properties of this catalyst are as follows:

Form Extrudate Size 1/10" ~Nom.1.8") 1/16"
Surface Area, m /gm 250 250 Total Pore Volume, cc/gm 0.55 0.55 Density, gm/cc 0. 73-0 . 74 0 . 73-0 . 74 Reacto~ Packed Density Ib/f t 41-43 41-43 Strength, lbs Crush 16-18 14-16 Attrition Index * 97 97 * Percentage retained on a 20-mesh sieve after tumbling for one half hour.

The combination of all of the hydro-treating condi-tions are selected to provide a relatively mild hydrotreatment which does not remove a predominant amount of the ni-trogen compounds. For instance, the higher the pressure, the higher ~he space veloci-ty should be to provide a mild treatment. In particular, above about 1200 psig the space velocity should desirable be at least about 2, and at and about 1600 psig the space velocity is preferably at .

, ' . . .

leas-t about 5.

A typical hydrotreating step employed according to the present invention involves the following conditions:
inle-t temperature 652F
pressure 1000 psig liquid hourly space velocity 1.96 hydrogen flow rate 5096 SCF/B
chemical hydrogen consumption 772 SCF/B

An analysis of a typical shale oil before and after such a hydrotreating siep is as follows:
B~fore Hydrotreating Gravity, API 22.9 Sulphur, PPM 7180 Nitrogen, PPM 10470 Carbon Weight Percent, 84.97 Hydrogen Weig:h-t Percent, 11.64 Arsenic, PPB 13700 Pour Point, F+60 Oxygen .838% (wt) After Hydrotreating Gravity 27.7 Sulphur 910 PPM
Nitrogen 9460 PPM
Arsenic 1 PPM
Pour Point Ft70 Oxygen .413 (wt) The hydrotreated shale oil material can then be subjected to a distillation, designated as 2, if desired to v~

provide an o~erhead shale oil distillate which .according to the desired end product boils at helow ~emperatures such as those in the range of about 100 to about 800F and a bottoms product. For instance, when the ultimate product is to be a jet fuel, the 5 overhead distillate can include ma terials which boil up to about 650F; whereas, when the ul-timate product is to be mainly gasoline, or JP-4, the overhead distilla-te preferably does not contain materials boiling above about 400F. ~ther temperatures at which this cut can be made are 500F and 450F. The distilla~ion is 10 optional and if desired the entire hydrotreated oil or any other fraction thereof can be subjected to the catalytic cracking step designated as 3. The overhead shale oil distillate can then be subjected to extraction with an aqueous solution of the phosphoric acid as will be discussed hereinbelow.

The catalytic cracking is a fluidized catalytic cracking process and can employ any of the well-known catalytic cracking processes and catalysts such as the activated clays or silica-magnesium catalysts such as those available under the trade designations SM-30 and SM 30SS from Davison Chemical, or silica zirconium cracking catalysts, or zeolites as suggested ;n U . S . Patent 3, 654 ,141 to Maryland, or the layered silicates such as the smectites. The preferred catalysts include the zeolite-containing catalysts and those silica con-taining catalysts which tend to provide greater amounts of middle distillate materials at about 600 to 650F.

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The preferred zeolite-con taining catalysts may include any zeolite, whe-ther natural, semi-synthetic or synthetic, alone or in admi~ture with other ma-terials which do not significantly impair the suitability of -the ca-talys-t. For example, if the catalyst is a 5 mi~ture, it may include -the zeolite componen t associa ted with or dispersed in a porous refractory inorganic oxide carrier; in such case the catalys-t may for example contain about 1% to abou-t 60%, more preferably about 1 to abou~ 40% and most typically about 5 to about 25% by weight, based on the to~al weight of catalyst (water 10 free basis) of the zeolite, the balance of the catalyst being the porous refractory inorganic oxide alone or in combination with any of the known adjuvants for promoting or suppressin~ various desired and undesired reactions. For a general explanation of the genus of zeolite, molecular sieve catalysts useful in the invention, 15 attention is drawn to the disclosures of the articles entitled "Refinery Catalysts are a Fluid Business" and "Making Cat Crackers Work on Varied Diet", appearing respectively in the July 26, 1978 and September 13, 1978 issues of Chemical Week magazine.

For the most part, the zeolite components of the zeolite-containing catalysts will be those which are known to be useful in FCC cracking processes. In general, these are crystalline aluminosilicates, typically made up of tetra coordina-ted aluminum 25 atoms associa-ted through oxygen atoms with adjacent silicon a toms in the crystal structure. However, the term "zeolite" as use(l in this disclosure 't *~ 3~g6 ;~
, 19 contemplates not only aluminosilicates, but also substances ih which the aluminum has been partly or wholly replaced, such as for instance by gallium and/or other metal atoms, and further includes substances in which all or part of the silicon has been replaced, such as for instance by germanium. Titanium and zirconium substitution may also be practiced.
Most zeolites are prepared or occur naturally in the sodium form, so that sodium cations are associated with 10 the electro negative sites in the crystal structure.
The presence of sodium cations is known to make the zeolites less stable when exposed to hydrocarbon conversion conditions, particularly high temperatures. Accordingly, the zeoli~e may be ion exchanged, and where the zeolite is a component of a catalyst composition, such ion exchanging may occur before or after incorpor~tion of the zeolite as a component of the composition. Sultable cations for replacemen~ of sodium in the zeolite crystal structure include ammonium (de~omposable to hydrogen? hydrogen, rare earth metals, alkaline earth metals, etc. Various suitable ion exchange procedures and cations which may be exchanged into the zeolite crystal structure are well known to those skilled in the art.
Examples o the naturally occurring crystalline aluminosilicate zeolites which may ~e used as or included in the catalyst for the present invention are faujasite, mordenite, clinoptilote, chabazite, analcite, erionite, as well as levynite, dachiardite, paulin~ite, noselite, ferriori-te, heulandite, scolccite, stibite, harmotome, phillipsite, brewsterite, flarite, datolite, ~melinite, caumnite, leucite, lazurite, scapli-te, mesolite, 5 ptholi~e, nepheline, matrolite, offretite and sodalite.

Examples of the synthetic crystalline aluminosilicate zeolites which are useful as or in the catalyst for carrying out the present invention are Zeolite X. U.S. Patent No. 2,882,244, Zeolite Y, U.S.
Patent No. 3,130,007; and Zeolite A, IJ.S. Paten-t No. 2,882,243; as well as Zeolite B, U . S . Patent No . 3,008,803; Zeolite D, Canada Patent No . 661,981; Zeolite E, Canada Patent No . 614,495; Zeolite F, U.S Patent No. 2,996,358; Zeolite H, U.S. Patent No.
3,010,789; Zeolite J, U.S. Patent No. 3,011,869; Zeolite L, Belgian Patent No. 575,177; Zeolite M, U.S. Patent No. 2,995,423, Zeolite O, U . S . Patent No . 3,140,252; Zeoli te Q, U . S . Patent No .

2,991,151; Zeolite S, U . S . Patent No . 3,054, ~57; Zeolite ~, U . S .
Patent No. 2,950,952; Zeolite W, U.S. Patent No. 3,012,853; Zeolite Z, Canada Patent No . 817,915. Also ZK-4HJ, alpha beta and ZSM-type zeoIil;es are useful. ~oreover, the zeolites described in U . S . Patents Nos . 3,140,249, 3,140,253, 3,044,482 and 4,137,151 are also useful, The crystalline aluminosilicate zeolites, such as synthetic faujasite, will under normal conditions crystallize as regularly shaped, discrete particles of approximately one to ten microns in size, and, accordingly, this is the size range normally used in 5 commercial catalysts. Preferably the particle size of the zeolites is Erom 0.5 to 1~ microns and more preferably is from 1 to 2 microns or less. For example, zeolites prepared in situ -from calcined kaolin may be characterized by even smaller crystallites. Blockage of the internal channels by, for e~ample, coke formation and contamination 10 by metals pbisoning will greatly reduce the total zeolite surface area. Therefore, to minimize the eEfect of contamination and pore blockage, crystals larger than the normal size cited above are preferably not used in the catalysts of this invention.

One example of riser ca-talytic cracking apparatus suitable for this cracking step is disclosed in U. S. Patent No. 4,070,159, This type of apparatus contains a chamber for disengagement of the catalyst and vapor which includes means for causing the vapors to undergo a sufficient change of direction relative to the direction travelled by 20 the catalyst particles whereby the vapors are suddenly and effectively separated from the catalyst.

The catalyst can be regenerated and reused in the present inven tion by heating to burn off any nitrogen material, which may have been adsorbed. The catalytic cracking is generally carried out at -temperatures of abou-t 900 to abou-t 1300F.
A typical catalytic cracking using a zeoli-te catalyst employed according to the present invention involves -the following conditions:

riser temp. at point of exit of oil and catalyst 1000F
catalyst regenera-tion -temperature 1325F
feed preheated temperature 500F
feed rate ~/hour 4.05 cat/feed ratio 16.8: 1 A full range shale oil having previously been hydrotreated as 10 discussed hereinabove and having a nitrogen conten-t of about 1.02%
is subjected to the above cracking. This cracking results in about a 71 volume percent conversion of materials boiling at above 570F
to materials boiling at or below 570F. The volume percent COnVerS1011 lS expresses as:
100 100 ~ quan-tit~v of 570 + material remaining in product quanhty of 570 + materlal m feed to cracker A 80 - 570F cut of the full range shale oil after hydrotrea-ting and before the cracking has a nitrogen content of about 0.9~%. A 80 -570F cut of the full range shale oil after cracking has a nitrogen ~0 content of about 0.39%. These nitrogen values indicate that -the cracking reswlts in removal of nitrogen. Even though these actual values seem somewha-t close, it must be remembered that the 80 -570F cut after the cracking includes addi-tional nitrogen compounds not in the 80 - 560F cut range prior to cracking. These additional 25 nitrogen materials are those which have been converted by the cracking from materials ~l ~ 8~!~96 ~3 boiling at above 570 F to those boiling at or below 570 F. The catalytic cracking facilitates the subsequent extraction of the nitrogen This may be due at least in part to the formatlon of lower molecular weight nitrogen compounds which ~ay be more easily extracted. Also, since ~he molecular weight of the nitrogen compounds is reduced, the total weight of material extracted is reduced; thereby resulting in reduced amounts of by-product.
The smount of the shale oil or distillate thereof which is fed to ~he catalytic cracking depends upon the desired product as mentioned hereinabove and is usually at least about 20% by wPight of the shale oil feed and can be 100% of the feed, and is preferably about 60 - 80%
of the feed. The cracked product contains significant amounts of olefinic materials due to the cracking.
In the event the initial hydrotreating discussed hereinabove is not carried out, the bottoms after the distillation could then be subjected to a mild hydrotreatment employing the conditions discussed hereinabove prior to the fluidized catalytic cracking procedure.
The catalytically cracked material or distillate portion thereof is then subjected to the extraction with aqueous phos-phoric acid. If desired, a bottoms portion o the cracked product can be subjected to a further hydrotreatment designated as 4 instead of being directly subjected to the extraction with squeous phosphoric acid which can employ the same general conditions as the above-discussed initial hydrotreatment. This hydrotreated materal can be recycled back to the catalytic cracking. The preferred catalysts employed in such ... , _- . - , ;

hydrotreatment are the nickel - molybdenum catalysts such as Nalco NM504 available from Nalco Chemical Company.
Nalco NM504 is a nickel ~ molbdenum catalyst on an aluminum support and has the following properties accord-ing to the manufactuler:
TYPICAL CHE~ICAL ANALYSIS, WT. %, DRY B~SIS

M 3~ 19~0%
NiO.... , ......... , ....... ..5.4%
Aluminum Base.... O......... Balance TYPICAL PHYSICAL PROPERTIES
Form Extrudate Size l/lO"(Nom.l/8") 1/16"
Surface Area, m2/gm 170 170 Total Pore Yolume,cc/gm 0.43 0.43 Density, gm/cc 0.88-0.90 0.~8-0.90 ~eactor Packed Density,lb/ft3 51~53 51-53 Strength, lbs Crush 16-18 14-16 Attrition Index* 97 97 ~ retained on à 20-mesh sieve after tumbling for one half hour.
As discus~sed hereinabove, the hydrotreated shale oil ordistillate thereof and catalytlcallycracked oilordistillate portion thereof are subjected to extraction with anaqueous aOlU~
tion of phosphoric acid designated as 5. The extraction is prefer-ablyconductedby countercurrent flow wherein the aqueous phosphoricacid is introduced into the upper part of a contact tower and the oil is pumped into the lower portion and up to~ards the upper portion of the contact tower by gravity dif-.......

.

?~925 ference. The aqueous phase containing the extracted ni~rogen materials i5 removed at the lower part and the treated oil ls removed from ~he upper part. Examples of ~ome types of suitable extraction appara~us include ro~ary disc towers, sieve tray towers, and packed towers.
The amount of acid ~mployed is generally at least sbout 0.3 parts by weight per 100 parts by weight of the oil being treated, and preferably about 0.5 to about 5 parts by weight per 100 parts by weight of the oil being treated. Usually, amounts greater than about 50 par~s by weight of phos~horic acid per 100 parts by weight of the oil being treated are not necessary. For the maximum practical and economical considerations, about .5 to about 7 parts by weight of acid are employed per 100 parts by weight of the oil, although as little as 3 parts by weight of acid can sometimes be used.
Ihe extraction is generally carried out at about room temperature and atmos~heric pressure. However, higher or lower pressure and temperatures can be employed if desired. In addition, it may be desirable to employ elevated temperature such as up to aboùt 150 F in order to facilitate flowing of the oil distillate. It if of course understood, that the acid composition employed should not be miscible with the oil to any significant extent.
The extraction ~tep is carried out in such a manner as to ensure intimate contact between the acid and oil. Such is achie~able by use of the types of apparatsu referred to hereinabove.

. . ' , ' , ' ' .

The concen-tration of the acid in -the aqueous composi tion can vary over a wide range. The use of very concentra-ted acid solutions, although suitable, are no-t especially preferred since the contact with the oil becomes increasingly difficul-t as the 5 concentration increases and -the -total volume of aqueous acid composition therefore decreases. Acid concentrations, up to abou-t 85% by weight are quite sui-table with concen-tra-tions of abou t 5 to about 55% by weight being preferred.

The feed to the acid extraction con-tains significant amounts o-f 10 olefins due to the cracking (e.g., in many cases at least abou-t 2 to about 5% by weight) and significant amounts of aromatics. I-t has been found according to the presen-t invention that -the use of phosphoric acid does not result in any significan-t polymerization of the olefins or dissolution of -the aromatics as would be expected 15 from experience with sulfuric acid. In fact, the prior knowledge with sulfuric acid would tend to lead persons skilled in the art to reduce the olefin and aromatic content to as low as possible prior to extraction. As discussed hereinabove, sulphuric acid causes polymerization of olefins and dissolution of aromatics. :[f desired, 20 the extraction can include a plurali-ty of extraction steps which can employ somewhat different conditions tailored -to preferentially effect certain types of material such as the olefins in one step and then to preferentially effect another type of ma-terial such as the naphthenics in another ex-trac-tion.

r I t is essential tha-t the acid employed be phosphoric acid since -the use o:E other acids will no-t provide -the results desired from -the presen-t invention. In particular, -the use of sulphuric acid could cause significan-t damage -to -the hydrocarbon being trea-ted and loss 5 of desired product as discussed hereinabove. Acetic acid is not deemed desirable since such could result in es-terifica-tion of the ma-terials being treated. Furthermore, the use of hydrochloric acid could result in reaction with the hydrocarbons and is -therefore undesirable from -this s-tandpoin-t. Moreover, the use of 10 hydrochloric acid suf~ers from corrosion problems which necessitate the use of equipment made from special corrosion resis-tance materials which significan-tly increase the cost. Still further, as apparent from the prior art, the use of the acids employed -therein resulted in formation of sludge which must be disposed of and from 15 which it is not practical to recover the acid or convert i-t -to a useful form. Disposal of such sludge is a critical problem. The sludge formation which has been experienced when using mineral acids other than those required by the present invention such as HC1 and H2SO4 at leas-t in part is believed to be a result of such 20 acids causing the polymerization of certain ma-terials present in the oil .

On the other hand, the present invention makes it possible to readily separate the acid from -the treated materials or -to merely add ammonia -to the aqueous phase af-ter use to resul-t in -the preparation of a useful material such as ammonium phosphates which will precipi-ta-te ou-t and which subsequently can be employed as a -fertilizer. The ammonia employed to produce, for instance, ammonium phospha-tes can be that which is produced in -the hydrotrea-ting steps of -the process.
The ability to produce useful materials such as ammonium phosphates and -the increased economics ob-tained thereby from the sale and/or beneficial use thereof Iurther enhances the commercial and economic a-ttractiveness o~ the present invention. ~orma-tion of sludge does not occur employing the present invention.

The produc-t from the ca-talytic cracking having a nitrogen content of about 0.39% is contacted with an aqueous H2Poa~ solution of about 53.3% acid concentra-tion . About 3 parts of acid are employed per 100 parts of the catalytically cracked product. The produc-t after separation -from the aqueous solution has a nitrogen content o:E only about 0.05% by weight.

The ~ollowing table illustrates the results ohtained from subjec-ting a shale oil dis-tillate boiling below 65CF after initial hydrotreating -to the different acid concentra-tion s-tated on the table . The dosage employed is abou-t 3.0 grams H3Po4 (100% acid basis)/100 grams of oil distillate. Nitrogen determinations are run on -the raffina-tes from each extraction. The total nitrogen content prior to extraction is . 2476 and -the basic ni-trogen prior to ex-traction is .2362.

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, , Next, the oil compo~ition containing the reduced amount of nitrogen content ls subjected to a hydrotreating designated as 6 which, because of the significantly reduced nitrogen content, is a relatively mild hydrotreating process.
The hydrG~reating at this stage is to assure hydrogenation of the oil to the desired values o~` the final products.
The conditions of this part;cular hydrotreating step are similar to those employed in the initial hydrotreating step 1 discussed hereinabove. A preferred type of catalyst for this hydro~reating is nickel molybdenum such ~s Aero HDS-3 and Aero HDS-3A from Am~rican Cyanamid C~mpany which according to the manufacturer has the following properties:

Loss on ignition at 900~F, wt.% 2.0 max . 2.0 ~ax Chemical!wt.~/O dr basis Molybdenum (~l0-03~ 14.5-16.0 14.5-16.0 Nickel (NiO) 3.0-4.0 3.0-4.0 50dium (Na20) 0.06 max 0.0~ max Iron (Fe) 0.05 max 0.05 max .
20 Physica~ Properties Average diameter, inches 0.11-~.13 0.055-0.067 Average length, inches 3 0.20-0.38 0.12-0.25 Poured bulk density, lb/ft 38-44 38-44 Crush strength, lb/mm* 3.0 min 2.5 min Surface area, m2/g~ ~ 140 min 140 min Pore volume, CCIgm 0.50-0.70 0.50-0.70 Fines, U.S. Std. Sieve -8 mesh, wt. % 0.5 max -16 mesh, wt. % 0.5 max 30 L~ss of Abrasion, wt. % 3.0 max 3.0 max ~Determination made wi~h 1/8" anvil . . , ~

The product can then be distilled as 7 and a fraction suitable for use as a diesel fuel can be taken off if desired. The overheads from the distillation can then be subjected to a catalytic reforming process designated as 8 which involves hydrocracking, isomerization, cycli-zation, dehydrogenation, and aromatication. A typical reforming catalyst e~ployed is a platinum or noble catalyst which can be supported on an inert carrier such as alumina.
The reforming at this stage is nonconventional as normally practiced and is employed specifically for forming jet or turbine fuels, since the specifications for such fuels is very restrictive with respect to the amounts of aromatics which can be present, and reforming produces aromatics.
However, in view of the use of shale oil as the feedstock, reforming is employed to both isomerize and crack n-paraffins which have a high freeze point so as ~o lower the freeze point ~o specification values. Some typical reforming conditions are as follows:
temperature about 850-125 F
pressure abouc 200-1000 psig hourly space velocity - about 2-25 hydrogenloil - about 4:1 Isomeri~ation is the primary objective of catalytic reformin~.
The hydrogen produced in the refor~ing can be used in the hydrotreatment steps of the process thereby reducing the amount of hydrogen which must be obtained from an external source. Typically about 300 SCF/B of hydrogen has been . been produced by the reforming.

. . . . , .. , ,. , , .. ... . . ............ .
.

The product can then be distilled ~designated as 9) and a frac-tion suitable for use as gasoline can be taken off if desired. The overheads from this distillation can be subjected to 8 hydrogenation desi~nated as 10 in order ~o saturate aromatic materials therein if turbine fuel is a desired product. The reforming as employed above increases the amount of aromatic materials in the oil. ~owever, when the product is employed as turbine fuel~ it is not desirable to have such hi~h quantities of aroma~ics. Accordingly, the hydrogenation step at this sta~e can be employed. The hydro-genation a~ this stage can be carried out em?loying the same general conditions discussed hereinabove for the initial hyd.otreatment step. A typical preferred embodiment set of conditions include:
temperature: about 650~ F
pressure: about ~OO psig hourly space veloci~y: about 3 The prefe~red catalyst ls a precious metal catalyst such as platinu~ and/or palladium on an alumina base 9 an example of which i~ disclosed in U.S. Patent 4,049,576 to Kovach, A nickel-molybdenum catalyst similar t~o the aforedescribed Aero HDS-3 and Aero HDS-3A from American Cyanamid Company can also be used.
The relative amounts of the product which are taken off as diesel fuel, gasoline and turbine fuel will depend primarily upon practical ~nd economical considerations such as rela~ive prices of ~uch fuels and the particular demands for each of the fuels at any one t~me. In fact, the process can be operated whereby the co~bustible fuels obtained can all be eitller diesel fuel or ~asoline or turbine f~el with none of the other two being produced. Accordin~,ly, the relative amount of any one of these fuels in comparison with the other two types can be anywhere fro~ 0 to 100%.

Claims (74)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method for treating shale oil to maximize the production of turbine jet fuel therefrom which comprises the steps of:
a) mildly hydrotreating shale oil or shale distillate or mixtures thereof for removal of sulfur and arsenic therefrom and for increasing the ratio of basic nitrogen compounds to total nitrogen compounds;
b) distilling said hydrotreated shale oil into a first fraction boiling at a temperature less than about 600 to about 650° F and into a second fraction boiling at a temperature greater than about 600 to about 650° F, said temperaure being selected according to the desired boiling point of the jet fuel to be produced;
c) catalytically cracking said second hydro-treated fraction boiling at a temperature greater than about 600 to 650° F;
d) contacting said first fraction boiling at a temperature less than about 600 to about 650° F with an aqueous solution of phosphoric acid whereby basic nitrogen materials in the oil product are extracted into the aqueous solution;
e) separating the aqueous solution containing said nitrogen materials from the oil product;

f) hydrotreating the oil containing the reduced amount of nitrogen;
g) subjecting the hydrotreated oil of reduced nitrogen content from step (f) or distillate thereof to reforming; and h) subjecting reformed product from step (g) or distillate thereof to a hydrogenation in order to provide said turbine fuel.

2. The method of claim 1 wherein the inlet temperature of the hydrotreating steps is about 350 to about 750° F, the pressure is about 300 to about 2000 psig, and the liquid hourly space velocity is about 0.5 to about 10.

3. The method of claim 1 wherein the tempera-ture for the hydrotreating steps is about 600 to about 700° F, the pressure is about 300 to about 1600 psig, and the liquid hourly space velocity is about 0.5 to about 10.

4. The method of claim 1 wherein the inlet temperature for the hydrotreating steps is about 625 to 675° F, the pressure is about 1000 psig, and the liquid hourly space velocity is 2 to about 3.

5. The method of claim 1 wherein said re-forming is carried out in the presence of a noble metal catalyst.

6. The method of claim 5 wherein said re-forming is carried out in the presence of a platinum catalyst.

7. The method of claim 1 wherein said hydro-genation is carried out in the presence of a noble metal catalyst.

8. The method of claim 1 wherein said hydro-genation is carried out in the presence of a platinum or palladium or mixture on an alumina base.

9. The method of claim 1 wherein said catalytic cracking is carried out at a temperature of about 900 to about 1300°F.

10. The method of claim 1 wherein said catalytic cracking is carried out in the presence of a zeolite catalyst.

11. The method of claim 1 wherein the cracked oil product is counter currently contacted with the aqueous solution of phosphoric acid.

12. The method of claim 11 wherein the aqueous phosphoric acid is introduced into the upper part of a contact zone and the oil is introduced into the lower portion of a contact zone.

13. The method of claim 1 wherein the amount of acid is at least about 0.3 parts by weight per 100 parts by weight of the oil product being treated.

14. The method of claim 1 wherein the amount of acid is about 0.5 to about 5 parts by weight per 100 parts by weight of the oil product being treated.

15. The method of claim 1 wherein the aqueous solution of phosphoric acid contains up to about 85% by weight of phosphoric acid.

16. The method of claim 1 wherein the aqueous solution of phosphoric acid contains about 5 to about 55% by weight of phosphoric acid.

17. The method of claim 1 wherein the oil feed to the acid extraction contains at least about 2% by weight of olefins.

18. The method of claim 1 wherein a cobalt-molybdate or nickel molybdate or mixture thereof is employed as a catalyst in the initial hydrotreating.

19. A method for converting shale oil to turbine fuel which comprises:

(a) catalytically cracking shale oil, or shale oil distillate or mixture thereof;

(b) contacting catalytically cracked oil product with an aqueous solution of phosphoric acid whereby basic nitrogen materials in the oil product are extracted into the aqueous solution;

(c) separating the aqueous solution containing said nitrogen materials from the oil product; and (d) hydrotreating the oil product containing the reduced amount of nitrogen and thereby obtain combustion fuel.

20. The method of claim 19 which further comprises subjecting hydrotreated oil of the reduced nitrogen content or distillate thereof to reforming.

21. The method of claim 20 wherein said reforming is carried out in the presence of a platinum or a noble metal catalyst.

22. The method of claim 20 wherein the reforming is carried out at a temperature of about 850 to about 925°F, a pressure of about 200 to about 1000 psig, hourly space velocity of about 2 to about 25.

23. The method of claim 20 wherein reformed product or distillate thereof is subjected to a hydrogenation to provide a turbine fuel.

24. The method of claim 23 wherein said hydrogenation is carried out in the presence of a noble metal catalyst.

25. The method of claim 23 wherein said hydrogenation is carried our in the presence of a platinum or palladium or mixture on an alumina base.

26. The method of claim 19 wherein said catalytic cracking is carried out at a temperature of about 900 to about 1300°F.

27. The method of claim 19 wherein said catalytic cracking is carried out in the presence of a zeolite catalyst.

28. The method of claim 19 wherein the cracked oil product is counter currently contacted with the aqueous solution of phosphoric acid.

29. The method of claim 28 wherein the aqueous phosphoric acid is introduced into the upper part of a contact zone and the oil is introduced into the lower portion of a contact zone.

30. The method of claim 19 wherein the amount of acid is at least about 0.3 parts by weight per 100 parts by weight of the oil product being treated.

31. The method of claim 19 wherein the amount of acid is about 0.5 to about 5 parts by weight per 100 parts by weight of the oil product treated.

32. The method of claim 19 wherein the aqueous solution of phosphoric acid contains up to about 85% by weight of phosphoric acid.

33. The method of claim 19 wherein the aqueous solution of phosphoric acid contains about 5 to about 55% by weight of phosphoric acid.

34. The method of claim 19 wherein the oil feed to the acid extraction contains at least about 2% by weight of olefins.

35. The method of claim 19 wherein the shale oil or shale oil distillate or mixtures thereof is subjected to an initial hydrotreating for removal of sulfur and arsenic therefrom prior to the catalytic cracking.

36. The method of claim 35 wherein a cobalt-molybdate or nickel molybdate or mixture thereof is employed as a catalyst in the initial hydrotreating.

37. The method of claim 35 wherein the inlet temperature of the hydrotreating steps is about 350 to about 750°F, the pressure is about 300 to about 2000 psig, and the liquid hourly space velocity is about 0.5 to about 10.

38. The method of claim 35 wherein the temper-ature for the hydrotreating steps is about 600 to about 700°F, the pressure is about 300 to about 1600 psig, and the liquid hourly space velocity is about 0.5 to about 10.

39. The method of claim 35 wherein the inlet temperature for the hydrotreating steps is about 625 to about 675°F, the pressure is about 1000 psig, and the liquid hourly space velocity is 2 to about 3.

40. A method for treating shale oil or shale oil distillate, or mixtures thereof which comprises:

(a) catalytically cracking said shale oil, or shale oil distillate or mixture thereof;

(b) contacting catalytically cracked oil product with an aqueous solution of phosphoric acid whereby basic nitrogen materials in the shale oil product are extracted into the aqueous solution; and (c) separating the aqueous solution containing said nitrogen materials from the oil product.

41. The method of claim 40 wherein said catalytic cracking is carried out at a temperature of about 900 to about 1300°F.

42. The method of claim 40 wherein said catalytic cracking is carried out in the presence of a zeolite catalyst.

43. The method of claim 40 wherein the cracked oil product is counter currently contacted with the aqueous solution of phosphoric acid.

44. The method of claim 43 wherein the aqueous phosphoric acid is introduced into the upper part of a contact zone and the oil is introduced into the lower portion of a contact zone.

45. The method of claim 40 wherein the amount of acid is at least about 0.3 parts by weight per 100 parts by weight of the oil product being treated.

46. The method of claim 40 wherein the amount of acid is about 0.5 to about 5 parts by weight per 100 parts by weight of the oil product being treated.

47. The method of claim 40 wherein the aqueous solution of phosphoric acid contains up to about 85% by weight of phosphoric acid.

48. The method of claim 40 wherein the aqueous solution of phosphoric acid contains about 5 to about 55% by weight of phosphoric acid.

49. The method of claim 40 wherein the oil feed to the acid extraction contains at least about 2% by weight of olefins.

50. A method for treating shale oil or shale oil distillate, or mixtures thereof which comprises:

(a) hydrotreating said shale oil or shale oil distillate to remove sulfur and arsenic therefrom and for increasing the ratio of basic nitrogen compounds to total nitrogen compounds;

(b) catalytically cracking hydrotreated shale oil or hydrotreated distillate portion thereof, or mixtures thereof;

(c) contacting catalytically cracked oil product with an aqueous solution of phosphoric acid whereby basic nitrogen materials in the shale oil product are extracted into the aqueous solution; and (d) separating the aqueous solution containing said nitrogen materials from the oil product.

51. The method of claim 50 wherein the total hydrogen consumption of said hydrotreating is up to about ]200 SCF/B of oil product being treated.

52. The method of claim 50 wherein the hydrogen consumption of the hydrotreating is at least about 50 SCF/B of oil being treated.

53. The method of claim 50 wherein the inlet tem-perature for the hydrotreating is about 350 to about 750°F.

54. The method of claim 50 wherein the inlet tem-perature of the hydrotreating is about 600 to about 700°F.

55. The method of claim 50 wherein the temperature of the hydrotreating is about 625 to about 675°F.

56. The method of claim 50 wherein the pressure of the hydrotreating is about 300 to about 2000 psig.

57. The method of claim 50 wherein the pressure of the hydrotreating is about 300 to about 1600 psig.

58. The method of claim 50 wherein the pressure of the hydrotreating is about 1000 psig.

59. The method of claim 50 wherein the liquid hourly space velocity employed in the hydrotreating is about 0.5 to about 10.

60. The method of claim 50 wherein the liquid hourly space velocity of hydrotreating is 2 to about 3.

61. The method of claim 50 wherein a cobalt-molybdate or nickel molybdate or mixture thereof is employed as a catalyst in the hydrotreating.

62. The method of claim 50 wherein the inlet temperature of the hydrotreating is about 350 to about 750°F, the pressure is about 300 to about 2000 psig, and the liquid hourly space velocity is about 0.5 to about 10.

63. The method of claim 50 wherein the temperature for the hydrotreating is about 600 to about 700°F, the pressure is about 300 to about 1600 psig, and the liquid hourly space velocity is about 0.5 to about 10.

64. The method of claim 50 wherein the inlet temperature for the hydrotreating is about 625 to about 675°F, the pressure is bout 1000 psig, and the liquid hourly space velocity is 2 to about 3.

65. The method of claim 1 wherein the inlet temperature of the hydrotreating in step (a) is about 350 to about 750° F, the pressure is about 300 to about 2000 psig, and the liquid hourly space velocity is about 0.5 to about 10.

66. The method of claim 1 wherein the temperature for the hydrotreating in step (a) is about 600 to about 700° F, the pressure is about 300 to about 1600 psig, and the liquid hourly space velocity is about 0.5 to about 10.

67. The method of claim 1 wherein the inlet temperature for the hydrotreating in step (a) is about 625 to about 675° F, the pressure is about 1000 psig, and the liquid hourly space velocity is 2 to about 3.

68. The method of claim 1 wherein the inlet temperature of the hydrotreating in step (f) is about 350 to about 750° F, the pressure is about 300 to about 2000 psig, and the liquid hourly space velocity is about 0.5 to about 10.

69. The method of claim 1 wherein the temperature for the hydrotreating in step (f) is about 600 to about 700° F, the pressure is about 300 to about 1600 psig, and the liquid hourly space velocity is about 0.5 to about 10.

70. The method of claim 1 wherein the inlet temperature for the hydrotreating in step (f) is about 625 to about 675°F, the pressure is about 1000 psig, and the liquid hourly space velocity is 2 to about 3.

71. The method of claim 1 wherein said hydrogenation is carried out in the presence of a cobalt or nickel molybdate catalyst.

72. A method for treating shale oil to maximize the production of turbine jet fuel therefrom which comprises the steps of:

(a) mildly hydrotreating shale oil or shale distillate or mixtures thereof for removal of sulfur and arsenic therefrom and for increasing the ratio of basic nitrogen compounds to total nitrogen compounds;

(b) distilling said hydrotreated shale oil into a first fraction boiling at a temperature less than about 500°F and into a second fraction boiling at a temperature greater than about 500°F, said temperature being selected according to the desired boiling point of the jet fuel to be produced;

(c) catalytically cracking said second hydrotreated fraction boiling at a temperature greater than about 500°F thereby producing a fraction boiling at less than about 500°F;

d) contacting said first fraction boiling at a temperature less than about 500° F
and said catalytically cracked hydrotreated fraction of (c) boiling at less than about 500° F with an aqueous solution of phosphoric acid whereby basic nitrogen materials in the oil product are extracted into the aqueous solution;
e) separating the aqueous solution containing said nitrogen materials from the oil product;
f) hydrotreating the oil product containing the reduced amount of nitrogen;
g) subjecting the hydrotreated oil of reduced nitrogen content from step (f) or distillate thereof to reforming; and h) subjecting reformed product from step (g) or distillate thereof to a hydrogenation in order to provide said turbine fuel.

73. A method for treating shale oil to maximize the production of turbine jet fuel therefrom which comprises the steps of:
a) mildly hydrotreating shale oil or shale distillate or mixtures thereof for removal of sulfur and arsenic therefrom and for increasing the ratio of basic nitrogen coupounds to total nitrogen compounds;

b) distilling said hydrotreated shale oil into a first fraction boiling at a temperature less than about 450° F and into a second fraction boiling at a temperature greater than about 450° F, said temperature being selected according to the desired boiling point of the jet fuel to be produced;
c) catalytically cracking said second hydrotreated fraction boiling at a temperature greater than about 450° F thereby producing a fraction boiling at less than about 450° F;
d) contacting said first fraction boiling at a temperature less than about 450° F and said catalytically cracked hydrotreated fraction of (c) boiling at less than about 450° F with an aqueous solution of phosphoric acid whereby basic nitrogen materials in the oil product are extracted into the aqueous solution;
e) separating the aqueous solution containing said nitrogen materials from the oil product;
f) hydrotreating the oil product containing the reduced amount of nitrogen;
g) subjecting the hydrotreated oil of reduced nitrogen content from step (f) or distillate thereof to reforming; and h) subjecting reformed product from step (g) or distillate thereof to a hydrogenation in order to provide said turbine fuel.

74. A method for treating shale oil to maximize the production of turbine jet fuel therefrom which comprises the steps of:
a) mildly hydrotreating shale oil or shale distillate or mixtures thereof for removal of sulfur and arsenic therefrom and for increasing the ratio of basic nitrogen compounds to total nitrogen compounds;
b) distilling said hydrotreated shale oil into a first fraction boiling at a temperature less than about 400° F and into a second fraction boiling at a temperature greater than about 400° F, said temperature being selected according to the desired boiling point of the jet fuel to be produced;
c) catalytically cracking said second hydro-treated fraction boiling at a temperature greater than about 400° F whereby producing a fraction boiling at less than about 400° F;
d) contacting said first fraction boiling at a temperature less than about 400° F and said catalytically cracked hydrotreated fraction of (c) boiling at less than about 400° F with an aqueous solution of phosphoric acid whereby basic nitrogen materials in the oil product are extracted into the aqueous solution;
e) separating the aqueous solution containing said nitrogen materials from the oil product;

f) hydrotreating the oil product containing the reduced amount of nitrogen;
g) subjecting the hydrotreated oil of reduced nitrogen content from step (f) or distillate thereof to reforming; and h) subjecting reformed product from step (g) or distillate thereof to a hydrogenation in order to provide said turbine fuel.