Note: Descriptions are shown in the official language in which they were submitted.
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PROCESS FOR THE HYDROTREATING OF
HEAVY HY~ROCARBON STREAMS
Background of the Invention
This invention is related to the catalytic treat-
ment in the presence of hydrogen of heavy hydrocarbonstreams containing asphaltenic material, metals, nitrogen
compounds, and sulfur compounds.
It is widely known that various organometallic
compounds and asphaltenes are present in petroleum crude
0 oils and other heavy petroleum hydrocarbon streams, such
as petroleum hydrocarbon residua, hydrocarbon streams
derived from tar sands, and hydrocarbon streams
derived from coal. The most common metals found in such
hydrocarbon streams are nickel, vanadium, and iron.
Such metals are very harmful to various petroleum
refining operations, such as hydrocracking, hydrode-
sulfurization, and catalytic cracking. The metals and
asphaltenes cause interstitial plugging of the catalyst
bed and reduced catalyst life. The various metal
deposits on a catalyst tend to poison or deactivate the
catalyst. Moreover, the asphaltenes tend to reduce the
susceptibility of the hydrocarbons to desulfurization.
If a catalyst, such as a desulfurization catalyst or a
fluidized cracking catalyst, is exposed to a hydrocarbon
fraction that contains metals and asphaltenes, the
; catalyst will become deactivated rapidly and will be
~! subject to premature removal from the particular reactor
and replacement by new catalyst.
Although processes for the hydrotreating of heavy
30 hydrocarbon streams, including but not limited to heavy
crudes, reduced crudes, and petroleum hydrocarbon residua,
are known, the use of fixed-bed catalytic processes to
convert such feedstocks without appreciable asphaltene
precipitation and reactor plugging and with effective
removal of metals and other contaminants, such as sulfur
compounds and nitrogen compounds, are not too common.
While the heavy portions of hydrocarbon streams once
could be used as a low-quality fuel or as a source of
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asphaltic-type materials, the politics and economics of
today require that such material be hydrotrea~ed to
remove environmental hazards therefrom and to obtain a
greater proportion of usable products from such feeds.
It is well known that petroleum hydrocarbon streams
can be hydrotreated, i.e., hydrodesulfurized, hydrode-
nitrogenated, and/or hydrocracked, in the presence of a
catalyst comprising a hydrogenating component and a
suitable support material, such as an alumina, an alumina-
silica, or silica-alumina. The hydrogenating component
comprises one or more metals from Group VI and/or Group
VIII of the Periodic Table of Elements, such as the
Periodic Table presented on page 628 of WEBSTER'S SEVENTH
NEW COLLEGIATE DICTIONARY, G. & C. Merriam Company,
Springfield, Massachusetts, U.S.A. (1963). Such combi-
nations of metals as cobalt and molybdenum, nickel and
molybdenum, cobalt, nickel, and molybdenum, and nickel
and tungsten have been found useful. For example,
United States Patent No. 3,340,180 teaches that heavy
20 hydrocarbon streams containing sulfur, asphaltic
materials, and metalliferous compounds as contaminants
can be hydrotreated in the presence of a catalyst com-
prising such metal combinations and an activated alumina
having less than 5% of its pore volume that is in the
form of pores having a radius of 0 Angstrom units ¦A]
(O nm) to 300 A (30 nm) in pores larger than l00 A
(l0 nm) radius and having less than 10% of said pore
volume in pores larger than 80 A (8 nm) radius.
United States Patent No. 4,016,067 discloses that
30 heavy hydrocarbon streams can be demetalated and desul-
furized in a dual catalyst system in which the first
catalyst comprises a Group VI metal and a Group VIII
metal, preferably molybdenum and cobalt, composited with
an alumina support having a demonstratable content of
35 delta and/or theta alumina and has at least 60% of its
pore volume in pores having a diameter of about l00 A
(l0 nm) to 200 A (~0 nm), at least about 5% of its pore
volume in pores greater than 500 A (50 nm) in diameter,
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and a surface area of up to about 110 square meters per
gram (m /gm) and in which the second catalyst comprises
a similar hydrogenating component composited with a
refractory base, preferably alumina, and has at least
50%, and preferably at least 60%, of its pore volume
contributed by pores that have a diameter of 30 A (3 nm)
to 100 A (10 nm) and a surface area of at least 150
m /gm.
United States Patent No. 2,890,162 teaches that
o catalysts comprising active catalytic components on
alumina and having a most frequent pore diameter of 60 A
(6 nm) to 400 A (40 nm) and pores which may have di-
ameters in excess of 1,000 A (100 nm) are suitable for
desulfurization, hydrocracking, hydroforming of
naphthene hydrocarbons, alkylation, reforming of
naphthas, isomerization of paraffins and the like,
hydrogenation, dehydrogena~ion, and various types of
hydrofining operations, and hydrocracking of residua and
other asphalt-containing materials. It is suggested
that suitable active components and promoters comprise a
metal or a catalytic compound of various metals, molybde-
num and chromium being among 35 listed metals.
United Kingdom Patent Specification 1,051,341
discloses a process for the hydrodealkylation of certain
aromatics, which process employs a catalyst consisting
of the oxides or sulfides of a Group VI metal supported
- on alumina, having a porosity of 0.5 milliliters per
; gram (ml/gm) to 1.8 ml/gm and a surface area of 138
m2/gm to 200 m2/gm, at least 85% of the total porosity
30 being due to pores having a diameter of 150 A (15 nm) to
; 550 A (55 nm).
United States Patents Nos. 3,245,919 and 3,267,025
disclose hydrocarbon conversion processes, such as
reforming, hydrocracking, hydrodesulfurization, isomeri-
zation, hydrogenation, and dehydrogenation, that employa catalyst of a catalytic amount of a metal component
selected from metals of Group VI and Group VIII, such as
chromium, molybdenum, tungsten, iron, nickel, cobalt,
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and the platinum group metals, their compounds, and
mixtures thereof, supported on gamma-alumina obtained by
the drying and calcining of a boehmite alumina product
and having a pore structure totalling at least about 0.5
cc/gm in pores larger than 80 A (8 nm) in size.
United States Patent No. 3,630,888 teaches the
treatment of residuum hydrocarbon feeds in the presence
of a catalyst comprising a promoter selected from the
group consisting of the elements of Group VIB and
lo Group VIII of the Periodic Tab~e, oxides thereof, and
combinations thereof, and a particulate catalytic agent
of silica, alumina, and combinations thereof, having a
total pore volume greater than 0.40 cubic centimeters
per gram (cc/gm), which pore volume comprises micropores
and access channels, the access channels being
interstitially spaced through the structure of the
micropores, a first portion of the access channels
having diameters between about 100 A (10 nm) and about
1,000 A (100 nm), which first portion comprises 10% to
40% of the pore volume, a second portion of the access
channels having diameters greater than 1,000 A, (100 nm)
which second portion comprises 10% to 40% of the pore
volume, and the remainder of the pore volume being
micropores having diameters of less than 100 A (10 nm),
which remainder comprises 20% to 80% of the total pore
volume.
United States Patent No. 3,114,701, while pointing
out that in hydrofining processes nitrogen compounds are
removed from petroleum hydrocarbons in the presence of
various catalysts generally comprising chromium and/or
molybdenum oxides together with iron, cobalt, and/or
: nickel oxides on a porous oxide support, such as alumina
or silica-alumina, discloses a hydrodenitrification
process employing a catalyst containing large concen-
trations of nickel and molybdenum on a predominantly
alumina carrier to treat hydrocarbon streams boiling at
180F. (82C.) to about 1,050F. (566C.).
,
.
United States Patent No. 2,843,552 discloses that a
catalyst containing chromia in an appreciable amount
- with alumina provides a very good attrition resistant
catalyst, can have molybdenum oxide impregnated thereon,
and can be used in reforming, desulfurization, and
isomerization processes.
United States Patent No. 2,577,823 teaches that
hydrodesulfurization of heavy hydrocarbon fractions
containing from 1% to 6.5% sulfur in the form of organic
lo sulfur compounds, such as a reduced crude, can be con-
ducted over a catalyst of chromium, molybdenum, and
aluminum oxides, which catalyst is prepared by simul-
taneously precipitating the oxides of chromium and
molybdenum on a preformed alumina slurry at a pH of 6 to
8.
United States Patent No. 3,265,615 discloses a
method for preparing a supported catalyst in which a
catalyst carrier of high surface area, such as alumina,
is impregnated with ammonium molybdate and then immersed
in an aqueous solution of chromic sulfate, and the
treated carrier is dried overnight and subsequently
reduced by treatment with hydrogen at the following
sequential temperatures: 550F. (288C.) for 1/2 hour;
750F. (399C.) for 1/2 hour; and 950F. (510C.) for
1/2 hour. The reduced material is sulfided and employed
to hydrofine a heavy gas oil boiling from 650F. (343C.)
to 930~F. (493C.).
United States Patent No. 3,95~,105 discloses a
process for hydrotreating petroleum hydrocarbon fractions,
such as residual fuel oils, which process employs a
catalyst comprising a Group VIB metal (chromium, molybde-
num, tungsten), a Group VIII metal (nickel, cobalt) and
a refractory inorganic oxide, which can be alumina,
silica, zirconia, thoria, boria, chromia, magnesia, and
35 composites thereof. The catalyst is prepared by dry
mixing a finely divided Group VIB metal compound, a
Group VIII metal compound, and a refractory inorganic
oxide, peptizing the mixture and forming an extrudable
dough, extruding, and calcining.
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United States Patent No. 3,64~,817 discloses a
two-stage process for treating asphaltene-containing
hydrocarbons. Both catalysts in the process comprise
one or more metallic components selected from the group
consisting of molybdenum, tungsten, chromium, iron,
cobalt, nickel, and the platinum group metals on a
porous carrier material, such as alu~ina, silica,
7irconia, magnesia, titania, and mixtures thereof, the
first catalyst having more than 50% of its macropore
0 volume characterized by pores having a pore diameter
that is greater than about 1,000 A (100 nm) and the
second catalyst having less than 50% of its macropore
volume characterized by pores having a pore diameter
that is greater than about 1,000 A (100 nm).
United States Patent No. 3,957,622 teaches a two-
stage hydroconversion process for treating asphaltene-
containing black oils. Desulfurization occurs in the
first stage over a catalyst that has less than 50% of
; its macorpore volume characterized by pores having a
20 pore diameter greater than about 1,000 A (100 nm).
Accelerated conversion and desulfurization of the
asphaltenic portion occur in the second stage over a
catalyst having more than 50% of its macropore volume
characterized by pores having a pore diameter that is
25 greater than 1,000 A (100 nm). Each catalyst comprises
one or more metallic components selected from the group
consisting of molybdenum, tungsten, chromium, iron,
cobalt, nickel, the platinum group metals, and mixtures
thereof on a support material of alumina, silica,
30 zirconia, magnesia, titania, boria, strontia, hafnia, or
mixtures thereof.
French patent publication No. 2,281,972 teaches the
preparation of a catalyst comprising the oxides of
cobalt, molybdenum, and/or nickel on a base of aluminum
35 oxide and 3 to 15 wt.% chromium oxide and its use for
the refining of hydrocarbon fractions, preferably for
the hydrodesulfurization of fuel oils obtained by vacuum
distillation or residual oils obtained by atmospheric
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distillation. The base can be prepared by co-precipi-
tation of compounds of chromium and aluminum.
United States Patent No. 3,162,596 teaches that, in
an integrated process, a residual hydrocarbon oil con-
S taining metal contaminants (nickel and vanadium) isfirst hydrogenated ei~her with a hydrogen donor diluent
or over a catalyst having one or more hydrogenation
promoting metals supported on a solid carrier exempli-
fied by alumina or silica and then vacuum distilled to
1~ separate a heavy gas oil fraction containing reduced
quantities of metals from an undistilled residue boiling
primarily above about 1,100F. (593C.) and containing
asphaltic material. The heavy gas oil fraction is
subsequently catalytically cracked.
lS United States Patent No. 3,180,820 discloses that a
- heavy hydrocarbon stock can be upgraded in a two-zone
hydrodesulfurization process, wherein each zone employs
a solid hydrogenation catalyst comprising one or more
metals from Groups VB, VIB, and VIII of the Periodic
Table of Elements. Either catalyst can be supported or
unsupported. In a preferred embodiment, the first zone
contains an unsupported catalyst-oil slurry and the
second zone contains a supported catalyst in a fixed
bed, slurry, or fluidized bed. The support of the
supported catalyst is a porous refractory inorganic
~; oxide carrier, including alumina, silica, zirconia,
magnesia, titania, thoria, boria, strontia, hafnia, and
complexes of two or more oxides, such as silica-alumina,
silica-zirconia, silica-magnesia, alumina-titania, and
silica-magnesia-zirconia, among others. The patent
provides that the supported catalyst which is appropri-
ate for use in the invention will have a surface area of
about 50 m~/gm to 700 m2/gm, a pore diameter of about 20 A
(2 nm) to 600 A (60 nm), and a pore volume of about
0.10 ml/gm to 20 ml/gm.
United States Patents Nos. 3,977,961 and 3,985,684
disclose processes for the hydroconversion of heavy
crudes and residua, which processes employ one or two
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catalysts, each of which comprises a Group VIB metal
and/or a Group VIII metal on a refractory inorganic
oxide, such as alumina, silica, zirconia, magnesia,
boria, phospha~e, titania, ceria, and thoria, can com-
prise a Group IVA metal, such as germanium, has a veryhigh surface area and contains ultra-high pore volume.
The first catalyst has at least about 20% of its total
pore volume of absolute diameter within the range of
about lO0 A (10 nm) to about 200 A (20 nm), when the
catalyst has a particle size diameter ranging up to 1/50
inch (0.051 cm), at least about 15% of its total pore
volume of absolute diameter within the range of about
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150 A (15 nm) to about 250 A (25 nm), when the catalyst
has a particle size diameter ranging from about 1/50
inch (0.051 cm) to about 1/25 inch (0.102 cm), at least
about 15% of its total pore volume of absolute diameter
within the range of about 175 A (17.5 nm) to about 275 A
(27.5 nm), when the catalyst has an average particle
size diameter ranging from about 1/25 inch (0.102 cm) to
about l/8 inch (0.32 cm~, a surface area of about 200
m2/gm to about 600 m2/gm, and a pore volume of about 0.8
; cc/gm to about 3.0 cc/gm. The second catalyst has at
least about 55% of its total pore volume of absolute
diameter within the range of about 100 A (10 nm) to
about 200 A (20 nm), less than 10% of its pore volume
with pore diameters of 50 A- (5 nm-), less than about
25% of its total pore volume with pore diameters of
300 A+ (30 nm~), a surface area of about 200 m2/gm to
about 600 m /gm, and a pore volume of about 0.6 cc/gm
to about 1.5 cc/gm. These patents teach also that the
effluent from such processes may be sent to a catalytic
cracking unit or a hydrocracking unit.
United States Patent No. 4,054,508 discloses a
; process for demetallization and desulfurization of
35 residual oil fractions, which process utilizes 2 cata-
lysts in 3 zones. The oil is contacted in the first
zone with a major portion of a first catalyst comprising
a Group VIB metal and an iron group metal oxide com-
posited with an alumina support, the first catalyst
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having at least 60% of its pore volume in pores of 100 A
(10 nm) to 200 A (20 nm) diameter and at least about 5%
of its pore volume in pores having a diameter greater
than 500 A (50 nm), in the second zone with the second
catalyst comprising a Group VIB metal and an iron group
metal oxide composited with an alumina support, the
second catalyst having a surface area of at least 150
m2/gm and at least 50% of its pore volume in pores with
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diameters of 30 A (3 nm) to 100 A (10 nm), and then in a
third zone with a minor portion of the first catalyst.
Now there has been found and developed a process
for hydrotreating a heavy hydrocarbon stream containing
metals, asphaltenes, nitrogen compounds, and sulfur
compounds, which process employs a catalyst that has
special physical characteristics and a hydrogenating
component comprising molybdenum and chromium and option-
ally cobalt.
Summary of the Invention
Broadly, according to the present invention, there
is provided a process for the hydrotreating of a heavy
hydrocarbon stream containing metals, asphaltenes,
nitrogen compounds, and sulfur compounds, which process
comprises contacting said stream under suitable con-
ditions and in the presence of hydrogen with a catalyst
comprising a hydrogenating component comprising molybde-
num and chromium, their oxides, their sulfides, and
mixtures thereof on a large-pore, catalytically active
alumina. The molybdenum can be present in an amount
within the range of about 5 wt.% to about 15 wt.%,
- 30 calculated as MoO3 and based upon the total catalyst
weight, and the chromium can be present in an amount
within the range of about 5 wt.% to about 20 wt.%,
calculated as Cr2O3 and based upon the total catalyst
weight. The catalyst possesses a pore volume within the
35 range of about 0.4 cc/gm to about 0.8 cc/gm, a surface
area within the range of about 150 m /gm to about 300
m /gm, and an average pore diameter within the range of
about 100 A (10 nm) to about 200 A (20 nm).
- 10 -
The catalyst can additionally con~ain cobalt and/or
its oxide, and/or its sulfide. When cobalt is present,
it is there in an amount within the range of about
0.1 wt.% to about 5 wt.%, calculated as CoO and based
upon the total catalyst weight.
The catalyst that is employed in the process of the
present invention can be prepared by calcining the
alumina (pseudo-boehmite) in air at a temperature of
about 800F. (427C.~ to about 1,400F. (760C.) for a
period of time within the range of about l/2 hour to
about 2 hours to produce a gamma-alumina and subse-
quently impregnating the gamma-alumina with one or more
aqueous solutions containing heat-decomposable salts of
the molybdenum and the chromium.
The catalyst that is employed in the process of the
present invention has about 0% to about 10% of its pore
volume in pores having diameters that are smaller than
50 A (5 nm), about 30% to about 80% of its pore volume
in pores having diameters within the range of about 50 A
(5 nm) to about 100 A (10 nm), about 10% to about 50% of
its pore volume in pores having diameters within the
range of about 100 A (10 nm) to about 150 A (15 nm), and
about 0% to about 10% of its pore volume in pores having
diameters that are larger than 150 A (15 nm~.
The process of the present invention is carried out
at a hydrogen partial pressure within the range of about
1,000 psia (6.9 MPa) to about 3,000 psia (29.7 MPa), an
average catalyst bed temperature within the range of
about 700F. (371C.) to about 820F. (438C.), a liquid
30 hourly space velocity (LHSV) within the range of about
0.1 volu~e of hydrocarbon per hour per volume of catalyst
to about 3 volumes of hydrocarbon per hour per volume of
catalyst, and a hydrogen recycle rate or hydrogen addition
rate within the range of about 2,000 standard cubic feet
; 35 of hydrogen per barrel of hydrocarbon [SCFB] (356 m3/m3)
to about 15,000 SCFB (2,672 m3/m3).
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Brief Description of the Drawing
The accompanying figure is a simplified flow diagram
of a preferred embodiment of the process of the present
invention.
Detailed Description of the Invention
The present invention is directed to a novel process
for the hydrotreating of heavy hydrocarbon feedstocks.
Such feedstocks will contain asphaltenes, metals, nitrogen
compounds, and sulfur compounds. It is to be understood
that the feedstocks that are to be treated by the process
of the present invention will contain from a small
amount of nickel and vanadium, e.g., less than 40 ppm,
up to more than 1,000 ppm of nickel and vanadium (a
combined total amount of nickel and vanadium) and up to
about 25 wt.% asphaltenes. If the feedstock contains
either a combined amount of nickel and vanadium that is
too large or an amount of asphaltenes that is exception-
ally large, the feedstock can be subjected to a pre-
liminary treatment to reduce the excessive amount of the
particular contaminant. Such preliminary treatment will
comprise a suitable hydrogenation treatment for the
removal of metals from the feedstock and/or the con-
version of asphaltenes in the feedstock to reduce the
contaminants to satisfactory levels, such treatment
employing any suitable relatively cheap catalyst. The
above-mentioned contaminants will deleteriously affect
the subsequent processing of such feedstocks, if they
are not lowered to acceptable levels.
Typical feedstocks that can be treated satis-
factorily by the process of the present invention willoften contain a substantial amount of components that
boil appreciably above 1,000F. (538C.). Examples of
typical feedstocks are crude oils, topped crude oils,
petroleum hydrocarbon residua, both atmospheric and
35 vacuum residua, oils obtained from tar sands and residua
derived from tar sand oil, and hydrocarbon streams
derived from coal. Such hydrocarbon streams contain
organometallic contaminants which create deleterious
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- 12 -
effects in various refining processes that employ cata-
lysts in the conversion of the particular hydrocarbon
stream being treated. The metallic contaminants that
are found in such feedstocks include, but are not
limited to, iron, vanadium, and nickel.
Nickel is present in the form of soluble organo-
metallic compounds in most crud~ oils and residuum
fractions. The presence of nickel porphyrin complexes
and other nickel organometallic complexes causes severe
difficulties in the refining and utilization of heavy
hydrocarbon fractions, even if the concentration of such
complexes is relatively small. It is known that a
cracking catalyst deteriorates rapidly and its se-
lectivity changes when in the presence of an appreciable
lS quantity of the organometallic nickel compounds. An
appreciable quantity of such organometallic nickel
compounds in feedstocks that are being hydrotreated or
hydrocracked harmfully affects such processes. The
catalyst becomes deactivated and plugging or increasing
of the pressure drop in a fixed-bed reactor results from
the deposition of nickel compounds in the interstices
between catalyst particles.
Iron-containing compounds and vanadium-containing
compounds are present in practically all crude oils that
are associated with the high Conradson carbon asphaltic
and/or asphaltenic portion of the crude. Of course,
such metals are concentrated in the residual bottoms,
when a crude is topped to remove those fractions that
boil below about 450F. (232C.) to 600F. (316C.). If
such residuum is treated by additional processes, the
presence of such metals adversely affects the catalyst
in such processes. It should be pointed out that nickel-
containing compounds deleteriously affect cracking
catalysts to a greater extent than do iron-containing
compounds. If an oil containing such metals is used as
a fuel, the metals will cause poor fuel oil performance
in industrial furnaces, since they corrode the metal
surfaces of the furnaces.
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While metallic contaminants, such as vanadium,
nickel, and iron, are often present in various hydro-
carbon streams in rather small a~ounts, they are often
found in concentrati~ns in excess of 40 to 50 ppm by
weight, often in excess of 1,000 ppm. Of course, other
metals are also present in a particular hydrocarbon
stream. Such metals exist as the oxides or sulfides of
the particular metal, or they are present as a soluble
salt of the particular metal, or they are present as
high molecular weight organometallic compounds, in-
cluding metal naphthenates and metal porphyrins, and
derivatives thereof. In any event, the feed stream can
be treated for demetallization prior to use in the
process of the present invention if the total amount of
lS nickel and vanadium is excessive.
Broadly~ according to the process of the present
invention, there is provided a process for hydrotreating
a heavy hydrocarbon stream containing metals, asphaltenes,
nitrogen compounds~ and sulfur compounds to reduce the
contents of metals, asphaltenes, nitrogen compounds, and
sulfur compounds in said stream, wherein said stream is
contacted with a catalyst under suitable conditions and
in the presence of hydrogen, characterized in that the
catalyst comprises a hydrogenating component comprising
the metals of molybdenum and chromium, their oxides,
their sulides, or mixtures thereof, on a large-pore,
catalytically active alumina, said molybdenum being
present in an amount within the range of about 5 wt.% to
about 15 wt.%, calculated as MoO3 and based upon the
total catalyst weightf said chromium being present in an
amount within the range of about 5 wt.% to about 20
wt.%, calculated as Cr203 and based upon the total
catalyst weight, and said catalyst possessing a pore
vo].ume within the range of about 0.4 cc/gm to about 0.8
cc/gm, a surface area within the range of about 150
m2/gm to about 300 m2/gm, and an a~erage pore diameter
within the range of about 100 A (10 nm) to about 200 A
(20 nm).
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The process of the present invention can be charac-
terized further in that the hydrogenating component of
said catalyst contains the metal cobalt, its o~ide, its
sulfide, or mixtures thereof, said cobalt being present
in an amount within the range of about 0.1 wt.% to about
5 wt.%, calculated as CoO and based upon the total
catalyst weight.
It is to be understood that as used herein all
values that are given for surface area would be those
that are obtained by ~he BET nitrogen adsorption method;
all values that are given for pore volume would be those
that are obtained by nitrogen adsorption; and all values
that are given for average pore diameter would be those
that are calculated by means of the expression:
A.P.D. = 4 x P V x 104
wherein A.P.D. = average pore diameter in A,
P.V. = pore volume in cc/gm, and
S.A. = surface area in m /gm.
Furthermore, pore size distributions are those that
are obtained by a Digisorb 2500 instrument through the
use of nitrogen desorption techniques.
In the process of the present invention, the cata-
lyst provides good demetallization activity, moderate
desulfurization activity, and possesses good stability
to deactivation, when being used at a high temperature
and/or moderate pressure, such as about 1,200 psig
(8.37 MPa).
The hydrogenating component of the catalyst that is
employed in the process of the present invention is a
particular component comprising molybdenum and chromium.
In one embodiment of the process of the present
invention, the hydrogenating component of the catalyst
35 consists essentially of molybdenum and chromium, their
oxides, their sulfides, or mixtures thereof. According
to this embodiment, there is provided a process for
hydrotreating a heavy hydrocarbon stream containing
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metals, asphaltenes, nitrogen compounds, and sulfurcompounds to reduce the contents of metals, asphaltenes,
nitrogen compounds, and sulfur compounds in said stream,
wherein said stream is contacted with a catalyst under
suitable conditions and in the presence of hydrogen,
characterized in that the catalyst comprises a hydro-
genating component consisting essentially of the metals
of molybdenum and chromium, their oxides, their sulfides,
or mixtures thereof, on a large-pore, catalytically
active alumina, said molybdenum being present in an
amount within the range of about S wt.% to about 15 wt.%
calculated as MoO3 and based upon the total catalyst
weight, said chromium being present in an amount within
the range of about S wt.% to about 20 wt.%, calculated
lS as Cr2O3 and based upon the total catalyst weight, and
said catalyst possessing a pore volume within the range
of about 0.4 cc/gm to about 0.8 cc/gm, a surface area
within the range of about 150 m /gm to about 300 m /gm~
and an average pore diameter within the range of about
100 A (10 nm) to about 200 A (20 nm).
Optionally, the hydrogenating component of the
catalyst that is used in the process of the present
invention can also contain cobalt. The molybdenum and
chromium and cobalt, when present, are present in the
elemental form, as oxides of the metals, as sulfides of
the metals, or mixtures thereof. The molybdenum is
present in an amount within the range of about S wt.% to
about lS wt.%, calculated as MoO3 and based upon the
total catalyst weight. The chromium is present in an
30 amount within the range of about 5 wt.% to about 20
wt.%, calculated as Cr2O3 and based upon the total
catalyst weight. The cobalt, when present, is present
in an amount within the range of about 0.1 wt.% to about
5 wt.%, calculated as CoO and based upon the total
35 catalyst weight. Preferably, the molybdenum is present
in an amount within the range of about 7 wt.% to about
13 wt.%, calculated as MoO3 and based upon the total
catalyst weight, the chromium is present in an amount
- 16 -
within the range of about 6 wt.% to about 15 wt.%,
calculated as Cr2O3 and based upon the total catalyst
weight, and the cobalt is present in an amount within
the range of about 1 wt.% to about 3 wt.%, calculated as
CoO and based upon the total catalyst weight.
Accordingly, there is provided a process for the
hydrotreating of a heavy hydrocarbon stream containing
metals, asphaltenes, nitrogen compounds, and sulfur
compounds to reduce the contents of metals, asphaltenes,
nitrogen compounds, and sulfur compounds in said stream,
wherein said stream is contacted with a catalyst under
suitable conditions and in the presence of hydrogen,
characterized in that the catalyst c~mprises a hydro-
genating component comprising molybdenum, chromium, and
cobalt, their oxides, their sulfides, and mixtures
thereof on a large-pore, catalytically active alumina,
said molybdenum being presen~ in an amount within the
range of about 5 wt.% to about 15 wt.%, calculated as
MoO3 and based upon the total catalyst weight, said
chromium being present in an amount within the range of
about 5 wt.% to about 20 wt.%, calculated as Cr2O3 and
based upon the total catalyst weight, said cobalt being
present in an amount within the range of about 0 wt.% to
about 5 wt.%, calculated as CoO and based upon the total
catalyst weight, and said catalyst possessing a pore
volume within the range of about 0.4 cc/gm to about
0.8 cc/gm, a surface area within the range of about 150
m2/gm to about 300 m2/gm, and an average pore diameter
within the range of about 100 A (10 nm) to about 200 A
(20 nm).
Suitable catalytically active large-pore aluminas
are employed in the catalyst that is utilized in the
process of the present invention. A typical example of
such an alumina is Aero-100 alumina, manufactured by the
35 American Cyanamid Company. The alumina s~ould have a
pore volume that is in excess of 0.4 cc/gm, a surface
area that is in excess of 150 m2/gm, and an average pore
diameter that is greater than 100 A (10 nm).
- . . .
' ~
.
- . .
. - - - .
.. . . -
.
- 17 -
Typically, the catalytic composition ~hat is em-
ployed in the process of the present invention may be
prepared by impregnating the various metals upon the
suitable catalytically active large-pore alumina. Such
impregnation may be accomplished with one or more
solutions of heat-decomposable compounds of the
appropriate metals. The impregnation may be a co-
impregnation when a single solution of the metals is
employed. Alternatively, impregnation may be accom-
plished by the sequential impregnation of the variousmetals from two or more solutions of the heat-decom-
posable compounds of t~e appropriate metals. The
impregnated support is dried at a temperature of at
least 250F. (121C.) for a period of at least 1 hour
and calcined in air at a temperature of at least 1,000F.
(538C.) for a period of time of at least 2 hours.
Preferably, the catalyst that is used in the process of
the present invention is prepared by first calcining
pseudo-boehmite in static air at a temperature of about
800F. (427~C.) to about 1,400F. (760C.) for a period
of time within the range of about 1/2 hour to about 2
hours to produce a gamma-alumina. This gamma-alumina is
subsequently impregnated with the aqueous solution or
solutions containing the heat-decomposable salts of the
cobalt, if present, and the molybdenum and chromium.
; The finished catalyst that is employed in the
process of the present invention possesses a pore volume
within the range of about 0.4 cc/gm to about 0 8 cc/gm,
a surface area within the range of about 150 m /gm to
about 300 m2/gm, and an average pore diameter within the
range of about 100 A (lO nm) to about 200 A (20 nm).
Preferably, the catalyst possesses a pore volume within
the range of about 0.5 cc/gm to about 0.7 cc/gm, a
surface area within the range of about 150 m2/gm to
about 250 m2/gm, and an average pore diameter within the
range of about llO A (11 nm) to about 150 A (15 nm).
The catalyst employed in the process of the present
; invention should have about 0% to about 10% of its pore
~, ,
.
. .
: :
volume in pores havinK ~iameters that are smaller than
50 A (5 nm), about 30% to about 80% of its pore volume
in pores having diameters within the range o~ about 50 A
(5 nm) to about 100 A (10 nm), about 10% to about 50% of
its pore volume in pores having diameters within the
range of about 100 A (10 nm) to about 150 A (l~ nm), and
about 0% to about 10% of its pore volume in pores having
diameters that are larger than 150 A (15 nm).
The process of the subject application is particu-
: lO larly useful for hydrotreating heavy hydrocarbon streams
such as petroleum residua, both atmospheric resids and
vacuum resids, tar sands oils, tar sands resids, and
liquids obtained from coal. In addition, the process
may be employed to satisfactorily hydrotreat petroleum
hydrocarbon distillates, such as gas oils, cycle stocks,and furnace oils. I~ the amount of nickel and vanadium
is excessive or the concentration of asphaltenes is too
large, the feedstock should be subjected to a prelimi-
nary treatment to reduce the excessive amount or amounts
to more tolerable levels before the feedstock is used in
the process of the present invention.
Operating conditions for the hydrotreatment of
heavy hydrocarbon streams, such as petroleum hydrocarbon
residua and the like, comprise a hydrogen partial
25 pressure within the range of about 1,000 psia (6.9 MPa)
to about 3,000 psia (20.7 MPa), an average catalyst bed
temperature within the range of about 700F. (371C.) to
about 820F. (438C.), a LHSV within the range of about
0.1 volume of hydrocarbon per hour per volume of cata-
lyst to about 3 volumes of hydrocarbon per hour pervolume of catalyst, and a hydrogen recycle rate or
hydrogen addition rate within the range of abou-t 2,000
SCFB ~356 m3/m3) to about 15,000 SCFB (2,672 m3/m3).
Preferably, the operating conditions comprise a hydrogen
35 partial pressure within the range of about 1,200 psia
(8.27 MPa) to about 2,000 psia (13.8 MPa), an average
catalyst bed temperature wi~hin the range of about
730F. (388C.) to about 810F. (432C.), a LHSV within
- .. : . . ... .. . . .
:. : : . .... ..
,: . . .. .: : :. . :
- .. . .
, - . .
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.
.
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- 19 -
the range of about 0.4 to about 1, and a hydrogen recycle
rate or hydrogen addition rate within the range of about
5,000 SCFB (890 m3/m3) to about 10,000 SCFB (1,780 m3/m3).
If the process of the present invention were to be
used to treat hydrocarbon distillates, the operating
conditions would comprise a hydrogen partial pressure
within the range of about 200 psia (1.4 MPa3 to about
3,000 psia (20.7 MPa), an average catalyst bed temper-
ature within the range of about 600F. (316C.) to about
800F. (427C.), a LHSV within the range of about 0.4
volume of hydrocarbon per hour per volume of catalyst to
about 6 volumes of hydrocarbon per hour per volume of
catalyst, and a hydrogen recycle rate or hydrogen ad-
dition rate within the range of about 1,0~0 SCFB
(178 m3/m3) to about 10,000 SCFB (1,780 m3/m3). Pre-
ferred operating conditions for the hydrotreating of
hydrocarbon distillates comprise a hydrogen partial
pressure within the range of aboùt 200 psia (1.4 MPa) to
about 1,200 psia (8.27 MPa), an average catalyst bed
temperature within the range of about 600F. (316C.) to
about 750F. (399C.), a LHSV within the range of about
0.5 volume of hydrocarbon per hour per volume of cata-
lyst to about 4 volumes of hydrocarbon per hour per
volume of catalyst, and a hydrogen recycle rate or
hydrogen addition rate within the range of about 1,000
SCFB (178 m3/m3) to about 6,000 SCFB (1,069 m3/m3).
A preferred embodiment of the process of the present
invention is presented in the accompanying figure, which
is a simplified flow diagram and does not show various
30 pieces of auxiliary equipment, such as pumps, com-
pressors, heat exchangers, and valves. Since one having
ordinary skill in the art would recognize easily the
need for and location of such auxiliary equipment, its
omission is appropriate and facilitates the simplifi-
cation of the figure. This process scheme is presentedfor the purpose of illustration only and is not intended
to limit the scope of the present invention.
..
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.- .
'. ~.. :
.. ..
,~
-:
- 20 -
Referring to the figure, an Arabian light vacuum
resid~ containing about 4 wt.% sulfur, less than 0.5
wt.% nitrogen, and less than 100 ppm of nickel and
vanadium, is withdrawn from source 10 through line 11
into pump 12, whereby it is pumped through line 13. A
hydrogen-containing recy~le gas stream, discussed here-
inafter, is passed from line 14 into line 13 to be mixed
with the hydrocarbon feed stream to form a mixed hydrogen-
hydrocarbon stream. The mixed hydrogen-hydrocarbon
lo stream is then passed from line 13 into furnace lS where
it is heated to a temperature within the range of about
760F. (404C.) to about 780F. (416C.). The heated
stream is then passed through line 16 into reaction zone
17.
Reaction zone 17 comprises one or more reactors 9
each of which contains one or more fixed beds of cata-
lyst. The catalyst comprises a hydrogenation component
comprising about 5 wt.% to about 15 wt.% molyhdenum,
calculated as MoO3 and based upon the total ca~alyst
20 weight, and about 5 wt.% to about 20 wt.% chromium,
calculated as Cr2O3 and based upon the total catalyst
weight, on a large-pore, catalytically active alumina.
The molybdenum and the chromium are present either in
the elemental form, as oxides of the metals, as sulfides
of the metals, or as mixtures thereof. The catalyst has
a pore volume within the range of about 0.4 cc/gm to
abo~t 0.8 cc/gm, a surface area within the range of
about 150 m2/gm to about 300 m2/gm, an average pore
diameter within the range of about 100 A (10 nm) to
30 about 200 A (20 nm), and a pore-size distribution
wherein about 0% to about 10% of the pore volume has
pore diameters within the range of about 0 A ~0 nm) to
about 50 A (5 nm), about 30% to about 80% of the pore
volume has pore diameters within the range of about 50 A
(5 nm) to about 100 A (10 nm), about 10% to about 50% of
the pore volume has pore diameters within the range of
about 100 A (10 nm) to about 150 A (15 nm), and about 0%
to about 10% of the pore volume has pore diameters that
are larger than 150 A (15 nm).
- :
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., ' ' ' , ~ .
7~
The operating conditions employed in this scheme
comprise a hydrogen partial pressure of about 1,200 psia
(8.27 MPa) to about 1,600 psia (11.0 MPa), an average
catalyst bed temperature within the range of about
760F. (404C.) to about 780F. (416C.), an LHSV within
the range of about 0.4 volume of hydrocarbon per hour
per volume of catalyst to about 0.8 volume of hydro-
carbon per hour per volume of catalyst, and a hydrogen
recycle rate within the range of about 5,000 SCFB
o (890 m3/m3) to about 8,000 SCFB (1,425 m3/m3).
The effluent from reaction zone 17 is passed
through line 18 into high-temperature, high-pressure,
gas-liquid separator 19, which is operated at reactor
pressure and a temperature within the range of about
760F. (404C.~ to abou-t 780F. (416C.). In separator
19, hydrogen-containing gas is separated from the rest
of the effluent. The hydrogen-containing gas is passed
from separator 19 through line 20. It is cooled and sent
into light-hydrocarbon separator 21, wherein the con-
densed light hydrocarbons are separated from the hydrogen-
containing gas and withdrawn via line 22. The hydrogen-
containing gas is removed by way of line 23 and passed
into scrubber 24, wherein the hydrogen sulfide is removed
or scrubbed from the gas. The hydrogen sulfide is
removed from the system by way of line 25. The scrubbed
hydrogen-containing gas is then passed through line 14
where it can be joined by make-up hydrogen, if neces-
sary, via line 26. The hydrogen-containing gas stream
is then added to the hydrocarbon feed stream in line 13,
as described hereinabove.
The liquid portion of the effluent is passed from
the high-temperature, high-pressure, gas-liquid sepa-
rator 19 by way of line 27 to high-temperature flash
drum 28. In flash drum 28, the pressure is reduced to
atmospheric pressure and the temperature of the material
is within the range of about 700F. (371C.) to about
800F. (427~C.). In flash drum 28, the light hydro-
carbons containing not only the naphtha but those
.
.
.
.. . .
.
, . , , .: .
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.. . . . ~ :
-: . . . : . : : ~
- 22 -
distillates boiling up to a temperature of about 550F.
(288C.) to 600F. (316C.), such as fuel oils, is
flashed from the rest of the produc~ and is removed from
the system by way of line 29. Such light hydrocarbons,
which comprise about 1 wt.% to about 4 wt.% C4-material,
about 2 wt.% to 5 wt.% naphtha (C5-to-360F.
[C5-to-182C.] material), and about 10 wt.% to about 15
wt.% 360F.-650F. (182C.-343C.) material, based upon
hydrocarbon feed, can be separated into their various ~ :
components and sent to storage or to other processing
units.
The heavier material that is separated from the
light hydrocarbons, that is, material that boils at a
temperature above about 600F. (316C.), present in an
amount of about 60 wt.% to about 90 wt.% based upon the
hydrocarbon feed, is removed from flash drum 28 by way
of line 30 for use as feeds to other processes or as a
low-sulfur, heavy industrial fuel. Such liquid material
contains about 0.6 wt./~ to about 1.2 wt.% sulfur, about
1.0 wt.% to about 3.0 wt.% asphaltenes, and about 5 ppm
to about 15 ppm nickel and vanadium. Furthermore, more
than 50% of the 1,000F.+ (538C.+) material is con-
verted to 1,000F.- (538C.-) material.
This liquid effluent is passed via line 31 to
2S furnace 32, or other suitable heating means, to be
heated to a temperature as high as 800F. (427C.).
The heated stream from furnace 32 is passed by way
of line 33 into vacuum tower 34, where vacuum gas oil
(VGO) is separated from a low-sulfur residual fuel. The
30 ~GO is passed from vacuum tower 34 by way of line 35 to
storage or to a conventional catalytic cracking unit
; (not shown). The low-sulfur residual fuel is passed
from vacuum tower 34 by way of line 36 to storage or to
other processing units where it can be used as a source
35 of energY-
Alternatively, the material boiling above 600F.(316C.) that is removed from flash drum 28 through line
30 can be sent by way of line 37 to a resid catalytic
cracking unit (not shown).
!
.
'
- 23 -
The following examples are presented to facilitatethe understanding of the present invention and are
presented for the purposes of illustration only and are
not intended to limit the scope of the present in-
vention.
Example 1
A catalyst, hereinafter identified as Catalyst A,was prepared to contain 8.3 wt.% MoO3 and 8.3 wt.%
Cr2O3, based upon the total catalyst weight, on a large-
pore, catalytically active alumina. A 40.8-gram sample
of Aero-100 alumina, obtained from the American Cyanamid
Company, was impregnated with a solution containing
ammonium dichromate and ammonium molybdate. The Aero-lO0
alumina was in the form of 14-to-20-mesh (1.17-to-
0.83 mm) material and had been previously calcined ata temperature of about 1,200F. (649C.) in air for a
period of 2 hours.
The solution that was used for the impregnation was
prepared by dissolving 6.8 grams of the ammonium dichro-
20 mate and 5.3 grams of the ammonium molybdate in 40
milliliters of distilled water.
The impregnated alumina was dried under a heat lamp
in static air overnight to remove the excess water. The
dried material was then calcined in static air at a
temperature of 1,000F. (538C.) for a period of 2
hours. This finished catalyst, Catalyst A, is an embodi-
ment of the catalyst that is employed in the process of
the present invention.
Example 2
For comparative purposes, a commercially-available
catalyst was obtained from the American Cyanamid Company.
This commercial catalyst was identified as HDS-2A and
was specified by the American Cyanamid Company to contain
3 wt.% CoO and 13 wt.% MoO3 on an alumina support. This
3~ catalyst is identified hereinafter as Catalyst B.
Example 3
A second hydrotreating catalyst was employed for
comparative purposes. This catalyst was obtained from
- - ''~ '.
. . . .. . . . .. - - : -
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.. . . . .
: . . - - . : , :
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, -,. ~ .. . . :
- -
.
- : ,
the Nalco Chemical Company. The catalyst, identified
- hereinafter as Catalyst C, was specified to contain
about 3 wt.% CoO and 13 wt.% MoO3 on an alumina support.
The properties of Ca~alysts A, B, and C are presented
S hereinbelow in Table I.
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.
2729
- 25 -
TABLE I
CATALYST PROPERTIES
CATALYST A B C D
HYDROGENATION
COMPONENT, WT.%
CoO ____ 3 3 _ _
Cr2O3 8.3 ---- -___ __ _
MoO3 8.3 13 13 ----
PHYSICAL PROPERTIES
SURFACE AREA, m /gm208 330 284 222
PORE VOLUME, cc/gm0.600.61 0.61 0.73
AVG. PORE DIAM., A116 73 86 131
nm11.67.3 8.6 13.1
% OF PORE VOLUME IN:
0-50 A (0-5 nm~
PORES 6.3 26.7 14.2 1.4
50-100 A (5-10 nm~
PORES 69.5 58.8 76.3 56.7
100-150 A (10-15 nm)
PORES 23.1 4.3 2.1 36.6
150-200 A (15-20 nm)
PORES 0.4 1.6 0.7 1.6
200-300 A (20-30 nm)
PORES 0.3 2.1 1.1 1.4
300-400 A (30-40 nm)
PORES 0.1 0.8 0.8 0.4
400 A+ (40 nm+)
PORES 0.3 5.7 4.8 1.9
:`
.
.
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- 26 -
TABLE I (Cont'd.~
CATALYST PROPERTIES
CATALYST E F G
HYDROGENATION
COMPONENT, WT.%
CoO __ __ _ ___
Cr2O3 5.2 15.4
MoO3 9 8.6 7.7
10 PHYSI~AL PROPERTIES
SURFACE AREA, m /gm201 197 198
PORE VOLUME, cc/gm0.66 0.60 0.59
AVG. PORE DIAM., A 130 122 119
nm 13.0 12.2 11.9
% OF PORE VOLUME IN: :
0-50 A (0-5 nm)
PORES 3.1 2.2 2.7
50-100 A (5-10 nm)
PORES 68.0 64.8 65.8
100-150 A (10-15 nm)
PORES 27.8 30.6 30.2
O . .
150-200 A (15-20 nm)
PORES 0.2 0.8 0.2
I 200-300 A (20-30 nm)
:l 25 PORES 0.3 0.7 0.3
', 300-400 A (30-40 nm)
PORES 0.1 0.2 0.1
~; o
400 A+ (40 nm+)
PORES 0.5 0.6 0.5
; 30
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(
.1
~1~2729
In addition> the physical properties of the alumina that
was used as the suppor~ material for Catalyst A are
presented in Table I. This support material is identi-
fied as Catalyst D. The introduction of the metals into
the alumina did not affect appreciably the por~ size
distribution, pore volume, surface area, or average pore
diameter of the alumina.
Example 4
Three other catalysts were prepared to show the
effect of different concentrations of chromia upon the
catalyst which comprises approximately 9 wt.% molybdena
and an Aero-100 alumina support. These catalysts were
prepared according to the preparation method discussed
in Example 1 hereinabove. However, only the appropriate
lS amounts of the metals were used to provide the desired
compositions of the finished catalysts. These three
catalysts are identified hereinafter as Catalysts E, F,
and G and were prepared with the same type of Aero-100
alumina that was used in the preparation of Catalyst A.
Their chemical compositions and physical properties are
presented also in Table I hereinabove. Again it is seen
that the introduction of the metals onto and into the
alumina has not greatly affected the physical properties
of the alumina.
Example 5
Each of the above-discussed catalysts was tested
for its ability to convert an Arabian light vacuum
resid. Appropriate properties of this feedstock are
presented hereinbelow in Table II.
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- ~8 -
TABLE II
FEED PROPERTIES
Carbon, wt.% 84.91
Hydrogen, wt.% 10.61
H/C (atomic) 1.499
Nitrogen, wt.% 0.34
Sulfur, wt.% 4.07
Nickel, ppm 17.5
- lo Vanadium 51.1
1,000F.- (538C.-)fraction 13.6
Ramsbottom carbon, wt.% 15.2
Gravity, API 8.8
Density, at 15C., gm/cc 1.0080
Asphaltenes, wt.% 8.0
Oils, wt.% 39.2
Resins, wt.% 52.8
Resins/asphaltenes 6.6 -
. .
Each test was carried out in a bench-scale test
unit having automatic controls for pressure, flow of
reactants, and temperature. The reactor was made from
3/8-inch(0.95-cm)-inside-diameter stainless-steel,
; heavy-walled tubing. A 1/8-inch(0.32-cm)-outside-
diameter thermowell extended up through the center of
the reactor. The reactor was heated by an electrically-
heated steel block. The hydrocarbon feedstock was fed
to the unit by means of a Ruska pump~ a positive-dis-
` placement pump. The 14-to-20-mesh (1.17-to-0.83 mm)
30 catalyst material was supported on 8-to-10-mesh (2.38-to-
2.00 mm) alundum particles. Approximately 20 cubic
centimeters of catalyst were employed as the catalyst
bed in each test. This amount of catalyst provided a
catalyst bed length of about 10 inches (25.4 cm) to
35 about 12 inches (30.5 cm). A 10-inch (25.4 cm) layer of
8-to-10-mesh (2.38-to-2.00 mm) alundum particles was
placed over the catalyst bed in the reactor for each
test. The catalyst that was employed was located in the
-
- ~ . .
. - . -, , : : :
.
.- : : . . ,: . . .
t~7;~
- 29 -
annular space between the thermowell and the internal
wall of the 3/8-inch(0.95-cm)-lnside-diameter reactor.
Prior to its use, each catalyst was calcined in
still air at a temperature of about l,000F. (538DC.)
S ~or 1 hour. It was subsequently cooled in a desiccator
and loaded into the appropriate reactor.
The catalyst was then subjected to the following
pretreatment. The reactor was placed in the reactor
block at a temperature of 300F. (149C.). A gas
0 mixture containing 8 mole % hydrogen sulfide in hydrogen
was-passed over the catalyst at the rate of 1 standard
cubic foot per hour [SCFH] (28.3 l/hr) at a pressure of
500 psig (3.5 MPa) and a temperature of about 300F.
(149C.). After 10 to 15 minutes of such treatment, the
temperature of the block was raised to 400F. After at
least an additional 1 hour of time had elapsed and at
least 1 standard cubic foot (28.3 l) of gas mixture had
passed through the system, the temperature of the block
was raised to 700F. (371C.). Then the gas mixture was
passed through the catalyst bed for at least 1 additional
hour and in an amount of at least 1 standard cubic foot
(28.3 l). At this point, the gas mixture was discontinued,
hydrogen was introduced into the unit at a pressure of
1,200 psig (8.37 MPa), the flow of hydrogen was established
at a rate of about 0.6 SCFH (17 l/hr), and the temperature
was incre~ased to provide an average catalyst bed temper-
ature of 760F. (404C.). Subsequently, the hydrocarbon
flow was established at a rate that would provide an
LHSV of 0.59 volume of hydrocarbon per hour per volume
Of catalyst. Effluent from the reaction zone was
collected in a liquid product receiver, while the gas
that was formed was passed through the product receiver
~ to a pressure control valve and then through a wet test
; meter to an appropriate vent.
After a period of from 1 to 3 days, the average
catalyst bed temperature was increased to 7S0F. (416C.).
After an additional amount of time, e.g., about 3 to 5
days, the average catalyst bed temperature was increased
to about 800F. (427C.).
. . .
: . .
.
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. . . .
~27Z~
- 30 -
Selected samples were obtained from the product
receiver and were analyzed for pertinent information.
Results of the tests are presented hereinbelow in Table
III. These data were obtained from samples taken during
the fifth to ninth day of operation conducted at an LHSV
of 0.59 volume of hydrocarbon per hour per volume of
catalyst, a temperature of 800F. (427C.), and a
pressure of 1,200 psig (8.37 MPa), unless otherwise
indicated.
TABLE III
TEST ~ESULTS
Run No. 1 2 3 4
15 Catalyst A . B C E
Temperature, F. 800 800 780 780
C. 427 427 416 416
Pressure, psig 1,200 1,200 1,200 1,200
MPa 8.37 8.37 8.37 8.37
LHSV 0.59 0.59 0.59 0.59
: % Sulfur removal 65.4 77.4 85 59
% Nickel removal 85 43 48 40
% Vanadium removal 92.5 94.9 57 79
25 % Asphaltene
conversion 70 68.8 54 67.5
Liq~id gravity,
API 20.1 19.9 20.4 17.5
Density, at 15C.,
gm/cc 0.9328 0.9341 0.9310 0.9491
% Conversion of
I,000F.+ (538C.+)
material 59.1 47.3 40 ----
Days on Stream 6 7 7-18(1) 5
(1) Composite sample of material obtained from Day 7
through Day 18.
. ''' :
:
27~9
- 31 -
TABLE III
TEST RESULTS
Run No. 4 5 6
Catalyst E F G
Temperature, F. 800 800 800
C. 427 427 427
Pressure, psig 1,200 1,200 1,200
MPa 8.37 8.37 8.37
LHSV 0.59 0.59 0.59
% Sulfur removal 60.5 60 69.6
% Nickel removal 64 64 78
15 % Vanadium removal 81 87 90.6
% Asphaltene
conversion 66 70 71
Liquid gravity,
API 19.3 17.6 21.1
: 20 Density, at 15C.,
gm/cc 0.9378 0.9485 0.9267
% Conversion of
1,000F.+ (538C.+)
material 53 60.6 58.6
25 Days on Stream 9 10 7
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-, 35
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27~9
- 32 -
The results presented in Table III demonstrate that
the run employing Catalyst A, i.e., an embodiment of the
process of the present invention, was superior to the
two tests that employed other catalysts. The data show
that the process of the present invention provided
better nickel removal, about as good vanadium removal,
better asphaltene conversion, better conversion of the
1,000F.+ (538C.+) material, but less sulfur removal
than the processes employing the other catalysts.
Hence, the process of the present invention is a suit-
able process for demetallization, desulfurization,
asphaltene conversion, and conversion of 1,000F.+
(538C.+) material, when treating a heavy hydrocarbon
stream. Moreover, the data from Runs 1, 4, 5, and 6
show that the presence of the Cr2O3 in the catalyst
promoted better metals removal, sulfur removal,
asphaltene conversion, and conversion of l,000F.+
(538C.+) material to 1,000F.- (53~C.-) material.
Example 6
A catalyst, hereinafter identified as Catalyst H,
was prepared to contain 1.1 wt.% CoO, 8.2 wt.% MoO3, and
8.2 wt.% Cr2O3, based upon the total catalyst weight, on
a large-pore, catalytically active alumina. A 63.8-gram
sample of Aero-100 alumina, obtained from the American
Cyanamid Company, was impregnated with a solution con-
taining ammonium dichromate and ammonium molbydate. The
Aero-100 alumina was in the form of 14-to-20-mesh
(1.17-to-0.83 mm) material and had been previously
calcined at a temperature of about 1,200F. (649C.) in
30 air for a period of 2 hours.
The solution that was used for the impregnation was
prepared by dissolving 10.6 grams of ammonium dichromate
and 8.3 grams of ammonium molybdate in 80 milliliters of
distilled water. The alumina to be impregnated was
35 added to the solution and the resulting mixture was
allowed to stand overnight.
The impregnated alumina was dried subsequently
under a heat lamp in static air for a period of about 2
hours to remove the excess water. The dried material
27~g
- 33 -
was then calcined in static air at a temperature of
1,000F. (538C.) for a period of 2 hours.
One-half of the calcined material was impregnated
with a solution of cobalt nitrate. This solution was
prepar~d by dissolving 1.2 grams of Co(NO3)2.6H2O in 40
milliliters of distilled water. The mixture of calcined
material and solution was allowed to stand overnight.
The material was then dried under a heat lamp in
static air for a period of about 2 hours. The dried
material was calcined in static air at a temperature of
1,000F. (538C.) for a period of 2 hours. The finished
catalyst, Catalyst H, is a preferred embodiment of the
catalyst that is employed in the process of the present
invention. Its properties are listed hereinbelow in
Table I.
Example 7
A second catalyst, hereinafter identified as Cata-
lyst I, was prepared to contain 3.1 wt.% CoO, 8.1 wt.%
MoO3, and 8.1 wt.% Cr2O3 3 based upon the total catalyst
20 weight, on an Aero-100 alumina support. This catalyst
was prepared according to the preparation method dis-
cussed hereinabove in Example 6; however, the appropri-
ate amounts of metals were utilized to furnish the
desired composition. This catalyst, Catalyst I, is
another embodiment of the catalyst that is employed in
the process of the present invention. Its properties
are listed hereinbelow in Table IV.
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- 34 -
TABLE IV
CATALYST PROPERTIES
CATALYST H
HYDROGENATION
COMPONENT, WT.%
CoO 1.1 3.1
Cr2O3 8.2 8.1
MoO3 8.2 8.1
PHYSICAL PROPERTIES
SURFACE AREA, m /gm 176 186
PORE VOLUME, cc/gm 0.55 0.56
AVG. PORE DIAM., A 125 120
nm 12.5 12.0
% OF PORE VOLUME IN:
0-50 A (0-5 nm) PORES 3.9 4.7
o
50-100 A (5-10 nm) PORES66.3 65.4
100-150 A (10-15 nm) PORES 28.9 29.1
150-200 A (15-20 nm) PORES 0.3 0.3
200-300 A (20-30 nm) PORES 0.3 0.3
300-400 A (30-40 nm) PORES 0.1 0.1
400-600 A (40-60 nm) PORES 0.2 0.1
- .: . . .
72g
Example 8
Catalyst H and Catalyst I were each tested for
their respective ability to convert the Arabian light
vacuum resid described hereinabove in Table II. Each
. S test was conducted as described hereinabove in Example 5.
The results of these tests are presented herein-
below in Table V. Also presented in Table V are the
test results from Runs Nos. 1, 2, and 3, shown herein-
above in Table III.
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- 36 -
TABLE V
TEST RESULTS
RUN NO. 7 8
CATALYST H
OPERATING CONDITIONS
TEMPERATURE, F. 800 800
C. ~27 427
PRESSURE, psig 1,200 1,200
lo MPa 8.37 8.37
LHSV 0.59 0.59
SAMPLE FROM DAY 9 9
% SULFUR REMOVAL 75 83
15 % NICKEL REMOVAL 79 73
% VANADIUM REMOVAL 93 86
% ASPHALTENE CONVERSION 79 75
% CONVERSION OF 1,000F.+
(538C.+) MATERIAL 66 50
20 LIQUID GRAVITY, API 20.9 20.7
DENSITY, AT 15C.,
gm/cc 0.9280 0.9292
, -
.
. - . . : .
.
- . . . .
- 37 -
TABLE V (Cont'd).
TEST RESULTS
: RUN NO. 1 2 3
CATALYST A B C
S
OPERATING CONDITIONS
TEMPERATURE, F.800 800 780
C.427 427 416
PRESSURE, psig1,2001,200 1,200
MPa8.37 8.37 8.37
LHSV 0.59 0.59 0.5g
SAMPLE FROM DAY 6 7 7-18(1)
% SULFUR REMOVAL 65 77 85
15 % NICKEL REMOVAL 85 43 48
% VANADIUM REMOVAL 93 95 57
% ASPHALTENE CONVERSION 70 69 54
% CONVERSION OF 1,000F.+
(538C.+) MATERIAL 59 47 40
LIQUID GRAVITY, API20.1 19.9 20.4
DENSITY, AT 15C.,
gm/cc 0.9328 0.9341 0.9310
(1) Composite sample of material obtained from Day 7
through Day 18.
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7~9
- 38 -
These results demonstrate that Run No. 7, which is
a preferred embodiment of the process of the present
invention and which employs a preferred embodiment of
the catalyst that is employed in the process of the
5 present invention, provides overall superior performance
when compared to the other test runs. It furnishes good
desulfurization, good nickel removal, superior vanadium
removal, superior asphaltene conversion, and superior
conversion of l,000F.+ (538C.+) material to l,000F.-
(538C.-) material.
Run No. 8, which is another embodiment of the
process of the present invention, employs a catalyst
that contains more cobalt (3.1 wt.% CoO) than Catalyst A
(l.l wt.% CoO), but this larger amount still falls
within the broad range of O.l wt.% to 5 wt.% CoO that is
specified hereinabove for a catalyst that can be utilized
in the process of the present invention. The increased
amount of cobalt improves the desulfurization activity,
somewhat lowers the metals removal, asphaltene con-
20 version, and conversion of the l,000F.+ (538C+) ma-
terial to l,000F.- (538C.-) material of the catalyst.
Run No. l, utilizes a catalyst that contains
chromium and molybdenum, but not cobalt, in its hydro-
genating component. The absence of cobalt results in
less sulfur removal, slightly improved metals removal,
less asphaltene conversion, and less conversion of the
1,000F.+ (538C.+) material.
Runs Nos. 2 and 3 represent comparative tests
employing prior art catalysts. These two runs provided
30 essentially the same amount of desulfurization as that
furnished by the process of the present invention.
However, they gave poorer metals removal, asphaltene
conversion, and conversion of l,000F.+ (538C.+) ma-
terial to l,000F.- (538C.-) material.
In view of the above, the process of the present
invention represents a new and novel process for hydro-
treating heavy hydrocarbon streams. The use of a small
amount of cobalt in the catalyst in conjun~tion with
-
~lG2
- 39 -
two metals of Group VIB of the Periodic Table of
Elements, namely, chromium and molybdenum, unexpectedly
makes the process utilizing that catalyst a very
effective way to treat such heavy hydrocarbons.
WHAT IS CLAIMED IS:
.
