Zeolite containing catalyst support for denitrogenation of oil feedstocks

There is provided a zeolite containing catalyst support for denitrogenation of oil feedstocks such as shale oil. The denitrogenation catalyst contains an active hydrogenation catalyst component such as a nickel/molybdenum catalyst.

BACKGROUND 
This invention relates to a zeolite-containing catalyst for denitrogenation 
of hydrocarbon feedstocks. 
It is well known that many if not most hydrocarbon feedstocks contain 
contaminants, as for example sulfur, nitrogen and metals. It is desirable, 
particularly if these feedstocks are to be further processed, that the 
contaminants be removed. This is an operation usually requiring use of a 
catalyst. 
The high nitrogen content of shale oil is perhaps the major limitation in 
upgrading it to a refinable syncrude. The primary mode of denitrogenation 
is by conventional, catalytic hydrotreating. 
It has been conventional in the art to effect sulfur removal from 
hydrocarbon stocks by subjecting them to treatment with hydrogen at 
elevated temperature and pressure while in contact with a catalyst 
containing hydrogenating components. Typically the hydrogenating 
components of such prior art catalysts are Group VI-B or Group VIII 
metals, or their oxides or sulfides. These hydrogenating components may be 
supported on a variety of well-known carriers, for example, alumina, 
kieselguhr, zeolitic molecular sieves and other materials having high 
surface areas; U.S. Pat. No. 4,080,296. U.S. Pat. No. 3,546,103 teaches 
hydrodesulfurization with a catalyst of cobalt and molybdenum on an 
alumina base. U.S. Pat. No. 3,755,145 describes a process for preparing 
lube oils characterized by low pour points which utilizes a catalyst 
mixture comprising hydrogenation components, a conventional cracking 
catalyst which can be either crystalline or amorphous and a crystalline 
aluminosilicate of the ZSM-5 type. 
U.S. Pat. No. 3,894,938 relates to the catalytic dewaxing and 
desulfurization of high pour point, high sulfur gas oils to lower their 
sulfur content by contacting such an oil first with a ZSM-5 type zeolite 
hydrodewaxing catalyst which may contain a hydrogenation/dehydrogenation 
component in the presence or absence of added hydrogen followed by 
conventional hydrodesulfurization processing of the dewaxed intermediate. 
Copending application Ser. No. 310,550, filed Oct. 13, 1981, discloses and 
claims a single stage operation for hydrotreating and hydrodewaxing of 
petroleum residua using a dual catalyst system, i.e. a 
hydrodesulfurization catalyst combined with a metal-containing ZSM-5 
hydrodewaxing catalyst. 
Copending application Ser. No. 346,439, filed Feb. 8, 1982, discloses and 
claims a process for simultaneously hydrodesulfurizing and hydrodewaxing a 
petroleum residua using an active hydrotreating catalyst component 
supported on a zeolite-containing catalyst support. 
SUMMARY 
According to one aspect of the invention there is provided an improved 
process for the denitrogenation of a nitrogeneous hydrocarbon feedstock, 
said process employing a hydrotreating catalyst comprising an active 
hydrogenation component and an alumina support, the improvement comprising 
incorporating in said alumina support a crystalline aluminosilicate 
zeolite having a silica to alumina molar ratio of at least about 12 and a 
Constraint Index within the approximate range of about 1 to 12, the amount 
of said zeolite being sufficient to increase the denitrogenation/hydrogen 
consumption selectivity of said catalyst composition. 
According to another aspect of the invention, there is provided a process 
for the catalytic denitrogenation of a nitrogeneous hydrocarbon feedstock, 
said process consisting essentially of contacting a mixture of hydrogen 
and said feedstock at a hydrogen pressure of from about 500 to 3,000 psig, 
a temperature of from about 600.degree. to 850.degree. F. and a space 
velocity of from about 0.1 to 5.0 LHSV with a catalyst consisting 
essentially of 5-40 wt. % of a zeolite, 95-60 wt. % of alumina, based on 
alumina plus zeolite, and 10-30 wt. %, expressed as oxides, of at least 
one Group VIII metal selected from the group consisting of nickel, cobalt 
and iron, and at least one Group VIB metal, based on total catalyst, said 
zeolite being a crystalline aluminosilicate zeolite having a silica to 
alumina ratio of at least about 12 and a Constraint Index within the 
approximate range of 1 to 12. 
According to another aspect of the invention, there is provided a process 
for the denitrogenation of shale oil, said process employing a 
hydrotreating catalyst composition comprising an active hydrogenation 
component and an alumina support, said alumina support comprising a 
crystalline aluminosilicate zeolite having a silica to alumina molar ratio 
of at least about 12 and a Constraint Index within the approximate range 
of about 1 to 12, the amount of said zeolite being sufficient to increase 
the denitrogenation/hydrogen consumption selectivity of said catalyst 
composition. 
According to another aspect of the invention, there is provided a process 
for the catalytic denitrogenation of shale oil, said process consisting 
essentially of contacting a mixture of hydrogen and said shale oil at a 
hydrogen pressure of from about 500 to 3,000 psig, a temperature of from 
about 600.degree. to 850.degree. F. and a space velocity of from about 0.1 
to 5.0 LHSV with a catalyst consisting essentially of 5-40 wt. % of ZSM-5, 
95-60 wt. % of alumina, based on alumina plus zeolite, and 10-30 wt. %, 
expressed as oxides, of nickel and molybdenum.

DETAILED DESCRIPTION 
The relative proportion of Group VIII metal to Group VIB metal, expressed 
as oxides, in the novel system of this invention is not narrowly critical 
but the Group VIB metal, e.g. molybdenum, is usually utilized in greater 
amounts than the Group VIII metal, e.g. nickel. In general, the weight of 
Group VIB metal to Group VIII metal, expressed as oxides, based on total 
catalyst should range from 2 to 5 with 3 to 4 being particularly 
preferred. 
Examples of active hydrogenation components are combinations of oxides or 
sulfides of metals selected from the group consisting of (i) nickel and 
molybdenum, (ii) nickel and tungsten, and (iii) cobalt and molybdenum. 
Typical process conditions utilized in carrying out the novel process of 
this invention include a hydrogen pressure of about 500-3000 psig, a 
temperature of about 600.degree.-850.degree. F., and 0.1-5 LHSV based on 
the total complement of catalyst in the system. 
The crystalline zeolite component of the catalyst composition of the 
present invention comprises a member of a particular class of zeolitic 
materials which exhibit unusual properties. Although these zeolites have 
unusually low alumina contents, i.e. high silica to alumina mole ratios, 
they are very active even when the silica to alumina mole ratio exceeds 
30. The activity is surprising, since catalytic activity is generally 
attributed to framework aluminum atoms and/or cations associated with 
these aluminum atoms. These zeolites retain their crystallinity for long 
periods in spite of the presence of steam at high temperature which 
induces irreversible collapse of the framework of other zeolites, e.g. of 
the X and A type. Furthermore, carbonaceous deposits, when formed, may be 
removed by burning at higher than usual temperatures to restore activity. 
These zeolites, used as catalysts, generally have low coke-forming 
activity and therefore are conducive to long times on stream between 
regenerations by burning carbonaceous deposits with oxygen-containing gas 
such as air. 
An important characteristic of the crystal structure of this particular 
class of zeolites is that it provides a selective constrained access to 
and egress from the intracrystalline free space by virtue of having an 
effective pore size intermediate between the small pore Linde A and the 
large pore Linde X, i.e. the pore windows of the structure are of about a 
size such as would be provided by 10-membered rings of silicon atoms 
interconnected by oxygen atoms. It is to be understood, of course, that 
these rings are those formed by the regular disposition of the tetrahedra 
making up the anionic framework of the crystalline zeolite, the oxygen 
atoms themselves being bonded to the silicon (or aluminum, etc.) atoms at 
the centers of the tetrahedra. 
The silica to alumina mole ratio referred to may be determined by 
conventional analysis. This ratio is meant to represent, as closely as 
possible, the ratio in the rigid anionic framework of the zeolite crystal 
and to exclude aluminum in the binder or in cationic or other form within 
the channels. Although zeolites with a silica to alumina mole ratio of at 
least 12 are useful, it is preferred in some instances to use zeolites 
having substantially higher silica/alumina ratios, e.g. 1600 and above. In 
addition, zeolites as otherwise characterized herein but which are 
substantially free of aluminum, that is zeolites having silica to alumina 
mole ratios of up to infinity, are found to be useful and even preferable 
in some instances. Such "high silica" or "highly siliceous" zeolites are 
intended to be included within this description. Also to be included 
within this definition are substantially pure silica zeolites, that is to 
say those zeolites having no measurable amount of aluminum (silica to 
alumina mole ratio of infinity) but which otherwise embody the 
characteristics disclosed. 
Members of this particular class of zeolites, after activation, acquire an 
intracrystalline sorption capacity for normal hexane which is greater than 
that for water, i.e. they exhibit "hydrophobic" properties. This 
hydrophobic character can be used to advantage in some applications. 
Zeolites of the particular class useful herein have an effective pore size 
such as to freely sorb normal hexane. In addition, their structure must 
provide constrained access to larger molecules. It is sometimes possible 
to judge from a known crystal structure whether such constrained access 
exists. For example, if the only pore windows in a crystal are formed by 
8-membered rings of silicon and aluminum atoms, then access by molecules 
of larger cross section than normal hexane is excluded and the zeolite is 
not of the desired type. Windows of 10-membered rings are preferred, 
although in some instances excessive puckering of the rings or pore 
blockage may render these zeolites ineffective. 
Although 12-membered rings in theory would not offer sufficient constraint 
to produce advantageous conversions, it is noted that the puckered 12-ring 
structure of TMA offretite does show some constrained access. Other 
12-ring structures may exist which may be operative for other reasons and, 
therefore, it is not the present intention to entirely judge the 
usefulness of a particular zeolite solely from theoretical structural 
considerations. 
Rather than attempt to judge from crystal structure whether or not a 
zeolite possesses the necessary constrained access to molecules of larger 
cross-section than normal paraffins, a simple determination of the 
"Constraint Index" as herein defined may be made by passing continuously a 
mixture of an equal weight of normal hexane and 3-methylpentane over a 
sample of zeolite at atmospheric pressure according to the following 
procedure. A sample of the zeolite, in the form of pellets or extrudate, 
is crushed to a particle size about that of coarse sand and mounted in a 
glass tube. Prior to testing, the zeolite is treated with a stream of air 
at 540.degree. C. for at least 15 minutes. The zeolite is then flushed 
with helium and the temperature is adjusted between 290.degree. C. and 
510.degree. C. to give an overall conversion of between 10 percent and 60 
percent. The mixture of hydrocarbons is passed at 1 liquid hourly space 
velocity (i.e., 1 volume of liquid hydrocarbon per volume of zeolite per 
hour) over the zeolite with a helium dioxide to give a helium to (total) 
hydrocarbon mole ratio of 4:1. After 20 minutes on stream, a sample of the 
effluent is taken and analyzed, most conveniently by gas chromatography, 
to determine the fraction remaining unchanged for each of the two 
hydrocarbons. 
While the above experimental procedure will enable one to achieve the 
desired overall conversion of 10 to 60 percent for most zeolite samples 
and represents preferred conditions, it may occasionally be necessary to 
use somewhat more severe conditions for samples of very low activity, such 
as those having an exceptionally high silica to alumina mole ratio. In 
those instances, a temperature of up to about 540.degree. C. and a liquid 
hourly space velocity of less than one, such as 0.1 or less, can be 
employed in order to achieve a minimum total conversion of about 10 
percent. 
The "Constraint Index" is calculated as follows: 
##EQU1## 
The Constraint Index approximates the ratio of the cracking rate constants 
for the two hydrocarbons. Zeolites suitable for the present invention are 
those having a Constraint Index of about 1 to 12. Constraint Index (CI) 
values for some typical materials are: 
______________________________________ 
C.I. 
______________________________________ 
ZSM-4 0.5 
ZSM-5 8.3 
ZSM-11 8.7 
ZSM-12 2 
ZSM-23 9.1 
ZSM-35 4.5 
ZSM-38 2 
ZSM-48 3.4 
TMA Offretite 3.7 
Clinoptilolite 3.4 
Beta 1.5 
H-Zeolon (mordenite) 
0.4 
REY 0.4 
Amorphous Silica-Alumina 
0.6 
Erionite 38 
______________________________________ 
The above-described Constraint Index is an important and even critical 
definition of those zeolites which are useful in the instant invention. 
The very nature of this parameter and the recited technique by which it is 
determined, however, admit of the possibility that a given zeolite can be 
tested under somewhat different conditions and thereby exhibit different 
Constraint Indices. Constraint Index seems to vary somewhat with severity 
of operation (conversion) and the presence or absence of binders. 
Likewise, other variables such as crystal size of the zeolite, the 
presence of occluded contaminants, etc., may affect the constraint index. 
Therefore, it will be appreciated that it may be possible to so select 
test conditions as to establish more than one value in the range of 1 to 
12 for the Constraint Index of a particular zeolite. Such a zeolite 
exhibits the constrained access as herein defined and is to be regarded as 
having a Constraint Index in the range of 1 to 12. Also contemplated 
herein as having a Constraint Index in the range of 1 to 12 and therefore 
within the scope of the defined class of highly siliceous zeolites are 
those zeolites which, when tested under two or more sets of conditions 
within the above-specified ranges of temperature and conversion, produce a 
value of the Constraint Index slightly less than 1, e.g. 0.9, or somewhat 
greater than 12, e.g. 14 or 15, with at least one other value within the 
range of 1 to 12. Thus, it should be understood that the Constraint Index 
value as used herein is an inclusive rather than a exclusive value. That 
is, a crystalline zeolite when identified by any combination of conditions 
within the testing definition set forth herein as having a Constraint 
Index in the range of 1 to 12 is intended to be included in the instant 
zeolite definition whether or not the same identical zeolite, when tested 
under other of the defined conditions, may give a Constraint Index value 
outside of the range of 1 to 12. 
The particular class of zeolites defined herein is exemplified by ZSM-5, 
ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and other similar 
materials. 
ZSM-5 is described in greater detail in U.S. Pat. No. 3,702,886 and Re 
29,948. The entire descriptions contained within those patents, 
particularly the X-ray diffraction pattern of therein disclosed ZSM-5, are 
incorporated herein by reference. 
ZSM-11 is described in U.S. Pat. No. 3,709,979. That description, and in 
particular the X-ray diffraction pattern of said ZSM-11, is incorporated 
herein by reference. 
ZSM-12 is described in U.S. Pat. No. 3,832,449. That description, and in 
particular the X-ray diffraction pattern disclosed therein, is 
incorporated herein by reference. 
ZSM-23 is described in U.S. Pat. No. 4,076,842. The entire content thereof, 
particularly the specification of the X-ray diffraction pattern of the 
disclosed zeolite, is incorporated herein by reference. 
ZSM-35 is described in U.S. Pat. No. 4,016,245. The description of that 
zeolite, and particularly the X-ray diffraction pattern thereof, is 
incorporated herein by reference. 
ZSM-38 is more particularly described in U.S. Pat. No. 4,046,859. The 
description of that zeolite, and particularly the specified X-ray 
diffraction pattern thereof, is incorporated herein by reference. 
ZSM-48 is more particularly described in published European patent 
application No. 80 300463, which claims priority to U.S. application Ser. 
No. 13,640, filed Feb. 21, 1979, and Ser. No. 64,703, filed Aug. 8, 1979. 
The description of that zeolite, and particularly the specified X-ray 
diffraction pattern thereof, is incorporated herein by reference. 
In all of the foregoing zeolites, the original cations can be subsequently 
replaced, at least in part, by calcination and/or ion exchange with 
another cation. Thus, the original cations can be exchanged into a 
hydrogen or hydrogen ion precursor form or a form in which the original 
cations have been replaced by a metal of, for example, Groups II through 
VIII of the Periodic Table. Thus, it is contemplated to exchange the 
original cations with ammonium ions or with hydronium ions. Catalytically 
active forms of these zeolites would include, in particular, hydrogen, 
rare earth metals, calcium, nickel, palladium and other metals of Groups 
II and VIII of the Periodic Chart. 
It is to be understood that by incorporating by reference the foregoing 
patents to describe examples of specific members of the specified zeolite 
class with greater particularity, it is intended that identification of 
the therein disclosed crystalline zeolites be resolved on the basis of 
their respective X-ray diffraction patterns. As discussed above, the 
present invention contemplates utilization of such catalysts wherein the 
mole ratio of silica to alumina is essentially unbounded. The 
incorporation of the identified patents should therefore not be construed 
as limiting the disclosed crystalline zeolites to those having the 
specific silica-alumina mole ratios discussed therein, it now being known 
that such zeolites may be substantially aluminum-free and yet, having the 
same crystal structure as the disclosed materials, may be useful or even 
preferred in some applications. It is the crystal structure, as identified 
by the X-ray diffraction "fingerprint", which establishes the identity of 
the specific crystalline zeolite material. 
The specific zeolites described, when prepared in the presence of organic 
cations, are substantially catalytically inactive, possibly because the 
intra-crystalline free space is occupied by organic cations from the 
forming solution. They may be activated by heating in an inert atmosphere 
at 540.degree. C. for one hour, for example, followed by base exchange 
with ammonium salts followed by calcination at 540.degree. C. in air. The 
presence of organic cations in the forming solution may not be absolutely 
essential to the formation of this type zeolite; however, the presence of 
these cations does appear to favor the formation of this special class of 
zeolite. More generally, it is desirable to activate this type catalyst by 
base exchange with ammonium salts followed by calcination in air at about 
540.degree. C. for from about 15 minutes to about 24 hours. 
Natural zeolites may sometimes be converted to zeolite structures of the 
class herein identified by various activation procedures and other 
treatments such as base exchange, steaming, alumina extraction and 
calcination, alone or in combinations. Natural minerals which may be so 
treated include ferrierite, brewsterite, stilbite, dachiardite, 
epistilbite, heulandite, and clinoptilolite. 
Preferred crystalline zeolites for utilization herein include zeolite Beta, 
ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, and ZSM-48, with ZSM-5 
being particularly preferred. 
Crystalline zeolites used in the present invention will generally have a 
crystal dimension of from about 0.01 to 100 microns, more preferably from 
about 0.02 to 10 microns. 
In a preferred aspect of this invention, the zeolites hereof are selected 
as those providing among other things a crystal framework density, in the 
dry hydrogen form, of not less than about 1.6 grams per cubic centimeter. 
It has been found that zeolites which satisfy all three of the discussed 
criteria are most desired for several reasons. Therefore, the preferred 
zeolites useful with respect to this invention are those having a 
Constraint Index as defined above of about 1 to about 12, a silica to 
alumina mole ratio of at least about 12 and a dried crystal density of not 
less than about 1.6 grams per cubic centimeter. The dry density for known 
structures may be calculated from the number of silicon plus aluminum 
atoms per 1000 cubic Angstroms, as given, e.g., on Page 19 of the article 
ZEOLITE STRUCTURE by W. M. Meier. This paper, the entire contents of which 
are incorporated herein by reference, is included in PROCEEDINGS OF THE 
CONFERENCE ON MOLECULAR SIEVES, (London, April 1967) published by the 
Society of Chemical Industry, London, 1968. 
When the crystal structure is unknown, the crystal framework density may be 
determined by classical pyknometer techniques. For example, it may be 
determined by immersing the dry hydrogen form of the zeolite in an organic 
solvent which is not sorbed by the crystal. Or, the crystal density may be 
determined by mercury porosimetry, since mercury will fill the interstices 
between crystals but will not penetrate the intracrystalline free space. 
It is possible that the unusual sustained activity and stability of this 
special class of zeolites is associated with its high crystal anionic 
framework density of not less than about 1.6 grams per cubic centimeter. 
This high density must necessarily be associated with a relatively small 
amount of free space within the crystal, which might be expected to result 
in more stable structures. This free space, however, is important as the 
locus of catalytic activity. 
Crystal framework densities of some typical zeolites, including some which 
are not within the purview of this invention, are: 
______________________________________ 
Void Framework 
Volume Density 
______________________________________ 
Ferrierite 0.28 cc/cc 1.76 g/cc 
Mordenite .28 1.7 
ZSM-5, -11 .29 1.79 
ZSM-12 -- 1.8 
ZSM-23 -- 2.0 
Dachiardite .32 1.72 
L .32 1.61 
Clinoptilolite .34 1.71 
Laumontite .34 1.77 
ZSM-4 (Omega) .38 1.65 
Heulandite .39 1.69 
P .41 1.57 
Offretite .40 1.55 
Levynite .40 1.54 
Erionite .35 1.51 
Gmelinite .44 1.46 
Chabazite .47 1.45 
A .5 1.3 
Y .48 1.27 
______________________________________ 
When synthesized in the alkali metal form, the zeolite is conveniently 
converted to the hydrogen form, generally by intermediate formation of the 
ammonium form as a result of ammonium ion exchange and calcination of the 
ammonium form to yield the hydrogen form. In addition to the hydrogen 
form, other forms of the zeolite wherein the original alkali metal has 
been reduced to less than about 1.5 percent by weight may be used as 
precursors to the transition metal modified zeolites of the present 
invention. Thus, the original alkali metal of the zeolite may be replaced 
by ion exchange with other suitable metal cations of Groups I through VIII 
of the Periodic Table, including, by way of example, nickel, copper, zinc, 
palladium, calcium or rare earth metals. As indicated, it is generally the 
hydrogen form of the zeolite component which is ion exchanged with 
transition metal in accordance with the present invention. 
As has heretofore been stated, an essential ingredient of the catalyst of 
this invention is alumina. Alumina may be present in the catalyst in 
amounts ranging from 60 to 95 weight percent based on the weight of 
alumina plus zeolite. As is well known by those skilled in the art, the 
characteristic of composited alumina catalyst depends to a very large 
extent on the properties of the alumina. 
Aluminas possessing characteristics which are eminently suitable for the 
preparation of the catalyst of this invention are manufactured by the 
American Cyanamid Company under their trade name PA Alumina Powder, 
manufactured by Kaiser Aluminum and Chemical Corporation under their trade 
name SA Alumina Powder, as well as one manufactured by Conoco Chemical 
Company under their trade name CATA SB. 
The catalyst of this invention is typically prepared by mixing a zeolite 
such as ZSM-5 with a suitable alumina following by extruding, calcining, 
exchanging to low sodium content, drying, impregnating with a Group VIB 
metal salt solution, drying, impregnating with a Group VIII metal salt 
solution, and re-calcining. Other methods can be employed to prepare the 
catalyst of this invention. 
EXAMPLE 
Three NiMo/Al.sub.2 O.sub.3 catalysts were evaluated in a fixed-bed, 
down-flow hydroprocessing pilot unit. The properties of the catalysts (A, 
B and C) are shown in Table 1. The catalysts are 1/32" extrudates made of 
Kaiser Al.sub.2 O.sub.3 and having 0, 15, and 30 wt% ZSM-5, respectively. 
All catalysts were impregnated to 5.0 wt% NiO and 17.0 wt% MoO.sub.3. The 
catalysts were presulfided in a conventional manner prior to the 
hydrotreating runs. Three similar shale oil samples were used in the 
catalyst evaluation; the properties of these Paraho shale oils are shown 
in Table 2. Evaluation data are given in Tables 3 through 5. 
In Tables 1-5 the following abbreviations are noted. LHSV stands for liquid 
hourly space velocity in terms of volume of liquid per volume of catalyst 
bed. SCFB or SCF/B stands for standard cubic feet per barrel. CHG stands 
for charge. BP stands for boiling point. EP stands for end point. 
In Table 1, the wt % of ZSM-5 and Al.sub.2 O.sub.3 is based upon the weight 
of ZSM-5 plus Al.sub.2 O.sub.3, whereas the wt % of NiO and MoO.sub.3 is 
based upon the entire weight of the catalyst composition. 
TABLE 1 
______________________________________ 
Properties of NiMo/Al.sub.2 O.sub.3 Catalysts 
CATALYST A B C 
______________________________________ 
Composition 
Support 
ZSM-5 Wt % 0 15 30 
Al.sub.2 O.sub.3, Wt % 
100 85 70 
Catalyst 
NiO, Wt % 5 5 5 
MoO.sub.3, Wt % 17 17 17 
Physical Properties 
Pore Vol, cc/g 0.589 0.609 0.566 
Surface Area, m.sup.2 /g 
186 199 224 
Avg. Pore Dia., Angstrom 
127 116 101 
Density, g/cc 
Packed 0.64 0.67 0.64 
Particle 1.16 1.10 1.16 
Real 3.64 3.36 3.36 
Pore Vol Distribution 
PV % in Pores of 
0-30 .ANG. Dia. 11 17 14 
30-50 2 3 6 
50-80 12 2 17 
80-100 9 7 9 
100-150 51 31 31 
150-200 11 24 14 
200-300 1 2 5 
300+ 3 2 4 
______________________________________ 
TABLE 2 
______________________________________ 
Properties of Paraho Shale Oil 
Drum No. 1 2 3 
______________________________________ 
API Gravity 20.9 22.2 20.5 
Sulfur, Wt % 0.62 0.58 0.62 
Nitrogen, Wt % 
2.1 2.0 2.1 
Pour Point, .degree.F. 
-- 75 -- 
______________________________________ 
TABLE 3 
______________________________________ 
Denitrogenating Paraho Shale Oil With 0% ZSM-5 (Catalyst A) 
Run No. 1 2 3 
______________________________________ 
Avg. Reactor Temp., .degree.F. 
726 762 794 
Pressure, PSIG 2000 2000 2000 
LHSV 0.58 0.49 0.56 
H.sub.2 Cons., SCF/B Chg 
1585 1917 2008 
Gravity, API 36.2 39.0 42.0 
Sulfur, Wt % 0.07 0.04 0.02 
Nitrogen, Wt % 0.210 0.090 0.030 
______________________________________ 
TABLE 4 
______________________________________ 
Denitrogenating Paraho Shale Oil With 15% ZSM-5 (Catalyst B) 
Run No. 1 2 3 
______________________________________ 
Avg. Reactor Temp., .degree.F. 
725 762 795 
Pressure, PSIG 2000 2000 2000 
LHSV 0.56 0.60 0.61 
H.sub.2 Cons., SCF/B Chg 
1474 1574 1710 
Gravity, API 35.7 38.0 41.0 
Sulfur, Wt % 0.13 -- 0.07 
Nitrogen, Wt % 0.180 0.088 0.025 
Pour Point, .degree.F. 
75 70 40 
______________________________________ 
TABLE 5 
______________________________________ 
Denitrogenating Paraho Shale Oil With 30% ZSM-5 (Catalyst C) 
Run No. 1 2 3 4 
______________________________________ 
Avg. Reactor Temp., .degree.F. 
694 725 752 776 
Pressure, PSIG 2040 2035 2040 2010 
LHSV 0.51 0.52 0.48 0.52 
H.sub.2 Cons., SCF/B Chg 
1260 1418 1673 1684 
Gravity, API 32.5 34.9 37.1 38.7 
Sulfur, Wt % 0.04 0.08 0.04 0.06 
Nitrogen, Wt % 0.520 0.300 0.090 
0.065 
Pour Point, .degree.F. 
65 55 50 -- 
______________________________________ 
As indicated by the foregoing data, a reduction in pour point can be 
achieved by the process of the present invention. 
FIG. 1 shows the effect of ZSM-5 on catalyst denitrogenation/hydrogen 
comsumption selectivity. To reach a given product nitrogen level (e.g. 500 
ppm), the catalyst with 15% ZSM-5 required approximately 15% less hydrogen 
(approximately 300 scf/B less). The use of more ZSM-5 apparently has no 
further benefit in reducing the hydrogen consumption, probably because the 
large amount of ZSM-5 dilutes the hydrotreating catalyst, requiring higher 
temperatures for a given level of denitrogenation and thus producing more 
light gases. It is believed that the zeolite may aid the scission of the 
C-N bonds by the presence of some residual acidity. 
FIG. 2 compares the denitrogenation activities of the three catalysts. The 
catalyst with 15% ZSM-5 was more active by about 15.degree. F. than the 
catalysts containing 0% and 30% ZSM-5. Thus incorporation of ZSM-5 has the 
benefit of both improving the denitrogenation activity and the 
denitrogenation/hydrogen consumption selectivity.