U.S. patent number 3,891,541 [Application Number 05/392,708] was granted by the patent office on 1975-06-24 for process for demetalizing and desulfurizing residual oil with hydrogen and alumina-supported catalyst.
This patent grant is currently assigned to Mobil Oil Corporation. Invention is credited to Donald Milstein, Stephen M. Oleck, Howard S. Sherry, Thomas R. Stein.
United States Patent |
3,891,541 |
Oleck , et al. |
June 24, 1975 |
Process for demetalizing and desulfurizing residual oil with
hydrogen and alumina-supported catalyst
Abstract
This disclosure concerns the demetalization and desulfurization
of metal and sulfur containing petroleum oils, preferably those
containing residua hydrocarbon components, through the use of a
catalyst comprising a hydrogenating component composited on a
refractory base, preferably an alumina, whose pores are
substantially distributed over a narrow 180A to 300A diameter
range.
Inventors: |
Oleck; Stephen M. (Moorestown,
NJ), Stein; Thomas R. (Cherry Hill, NJ), Sherry; Howard
S. (Cherry Hill, NJ), Milstein; Donald (Cherry Hill,
NJ) |
Assignee: |
Mobil Oil Corporation (New
York, NY)
|
Family
ID: |
23551695 |
Appl.
No.: |
05/392,708 |
Filed: |
August 29, 1973 |
Current U.S.
Class: |
208/89; 208/251H;
208/216PP; 208/216R |
Current CPC
Class: |
B01J
35/10 (20130101); B01J 37/20 (20130101); C10G
45/08 (20130101); B01J 23/85 (20130101); C10G
65/12 (20130101); B01J 35/1085 (20130101); B01J
21/04 (20130101); B01J 23/882 (20130101); B01J
35/1038 (20130101); B01J 35/1061 (20130101); B01J
35/1042 (20130101); B01J 35/1014 (20130101) |
Current International
Class: |
C10G
45/02 (20060101); B01J 23/76 (20060101); B01J
23/85 (20060101); B01J 35/00 (20060101); B01J
37/00 (20060101); B01J 37/20 (20060101); B01J
35/10 (20060101); C10G 65/00 (20060101); C10G
45/08 (20060101); C10G 65/12 (20060101); C10g
023/02 () |
Field of
Search: |
;208/216,89,213,251H,210 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
3622500 |
November 1971 |
Alpert et al. |
3630888 |
December 1971 |
Alpert et al. |
3669904 |
June 1972 |
Cornelius et al. |
3712861 |
January 1973 |
Rosinski et al. |
3714032 |
January 1973 |
Bertolacini et al. |
3730879 |
May 1973 |
Christman et al. |
|
Primary Examiner: Gantz; Delbert E.
Assistant Examiner: Crasanakis; G. J.
Attorney, Agent or Firm: Huggett; Charles A. Gilman; Michael
G. Frilette; Vincent J.
Claims
What is claimed is:
1. A process for catalytically demetalizing and desulfurizing a
residual oil comprising contacting said oil with hydrogen under the
following hydroprocessing conditions: a hydrogen pressure of about
500 to 3000 psig, a hydrogen circulation rate of about 1000 to
15,000 scf/bbl of feed, a temperature of about 600.degree. to
850.degree.F, a space velocity of 0.1 to 5.0 LHSV, in the presence
of a catalyst comprising the oxides or sulfides of a Group VIB
metal and an iron group metal on an alumina support, said catalyst
having not less than about 55 to 75% of its pore volume in pores
having a diameter range of about 180A to about 300A, and having a
surface area in the range of 40 to 70 m.sup.2 /g.
2. The process as claimed in claim 1 wherein said process includes
the step of cracking said oil following said demetalation and said
desulfurization step, said cracking being carried out under the
following conditions: 800.degree.to 1500.degree.F. temperature, 1
to 5 atmospheres pressure and a space velocity of about 1 to 1000
WHSV.
3. The process as claimed in claim 1 wherein said process includes
the step of hydrocracking said oil following said demetalation and
desulfurization step, said hydrocracking being carried out under
the following conditions: 400.degree. to 1000.degree.F. temperature
and 100 to 3500 psig pressure.
4. The process as claimed in claim 1 wherein said process includes
the step of coking said oil following said demetalation and
desulfurization step, said coking being carried out under the
following conditions: 800.degree. to 1100.degree.F. temperature and
1 to 10 atmospheres pressure.
5. A process for catalytically desulfurizing a residual oil
comprising contacting said oil with hydrogen under the following
hydroprocessing conditions: a hydrogen pressure of about 500 to
3000 psig, a hydrogen circulation rate of about 1000 to 15,000
scf/bbl of feed, a temperature of about 600.degree. to
850.degree.F, a space velocity of 0.1 to 5.0 LHSV, in the presence
of a catalyst comprising the oxides or sulfides of a Group VIB
metal and an iron group metal on an alumina support, said catalyst
having not less than about 55 to 75% of its pore volume in pores
having a diameter range of about 180A to about 300A, and having a
surface area in the range of 40 to 70 m.sup.2 /g.
6. The process as claimed in claim 5 wherein said desulfurizing
step occurs at the following conditions: a hydrogen pressure of
2000 to 3000 psig, a temperature of about 725.degree. to
850.degree.F. and a space velocity of about 0.10 to 1.5.
7. The process as claimed in claim 6 wherein said process includes
the step of coking said oil following said desulfurization step,
said coking being carried out under the following conditions:
800.degree. to 1100.degree.F. temperature and 1 to 10 atmospheres
pressure.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to demetalation and desulfurization of
petroleum oils, preferably those containing residual hydrocarbon
components, and having a significant metals and sulfur content.
More particularly the invention relates to a
demetalation-desulfurization process for reducing high metals and
sulfur contents of petroleum oils, again preferably those
containing residual hydrocarbon components, by the use of catalytic
compositions that are especially effective for such a purpose.
2. Description of the Prior Art
Residual petroleum oil fractions such as those heavy fractions
produced by atmospheric and vacuum crude distillation columns, are
typically characterized as being undesirable as feedstocks for most
refining processes due primarily to their high metals and sulfur
content. The presence of high concentrations of metals and sulfur
and their compounds precludes the effective use of such residua as
chargestocks for cracking, hydrocracking and coking operations as
well as limiting the extent to which such residua may be used as
fuel oil. Perhaps the single most undesirable characteristic of
such feedstocks is the high metals content. Principal metal
contaminants are nickel and vanadium, with iron and small amounts
of copper also sometimes present. Additionally, trace amounts of
zinc and sodium are found in some feedstocks. As the great majority
of these metals when present in crude oil are associated with very
large hydrocarbon molecules, the heavier fractions produced by
crude distillation contain substantially all the metal present in
the crude, such metals being particularly concentrated in the
asphaltene residual fraction. The metal contaminants are typically
large organo-metallic complexes such as metal prophyrins and
asphaltenes.
At present, cracking operations are generally performed on
petroleum fractions lighter than residua fractions. Such cracking
is commonly carried out in a reactor operated at a temperature of
about 800.degree. to 1500.degree.F., a pressure of about 1 to 5
atmospheres, and a space velocity of about 1 to 1000 WHSV. Typical
cracking chargestocks are coker and/or crude unit gas oils, vacuum
tower overhead etc., the feedstock having an API gravity range of
between about 15 to about 45. As these cracking chargestocks are
lighter than residual hydrocarbon fractions, residual fractions
being characterized as having an API gravity of less than about 20,
they do not contain significant proportions of the heavy and large
molecules in which the metals are concentrated.
When metals are present in a cracking unit chargestock such metals
are deposited on the cracking catalyst. The metals act as a
catalyst poison and greatly decrease the efficiency of the cracking
process by altering the catalyst so that it promotes increased
hydrogen production.
The amount of metals present in a given hydrocarbon stream is
generally judged by petroleum engineers by making reference to a
chargestock's "metals factor." This factor is equal to the
summation of the metals concentration in parts per million of iron
and vanadium plus ten times the amount of nickel and copper in
parts per million. The factor may be expressed in an equation form
as follows:
F.sub.m = Fe + V + 10 (Ni + Cu)
A chargestock having a metals factor greater than 2.5 is indicative
of a chargestock which will poison cracking catalyst to a
significant degree. A typical Kuwait atmospheric crude generally
considered of average metals content, has a metals factor of about
75 to about 100. As almost all of the metals are combined with the
residual fraction of a crude stock, it is clear that metals removal
of 90 percent and greater will be required to make such fractions
(having a metals factor of about 150 to 200) suitable for cracking
chargestocks.
Sulfur is also undesirable in a process unit chargestock. The
sulfur contributes to corrosion of the unit mechanical equipment
and creates difficulties in treating products and flue gases. At
typical cracking conversion rates, about one half of the sulfur
charged to the unit is converted to H.sub.2 S gas which must be
removed from the light gas product, usually by scrubbing with an
amine stream. A large portion of the remaining sulfur is deposited
on the cracking catalyst itself. When the catalyst is regenerated,
at least a portion of this sulfur is oxidized to form SO.sub.2
and/or SO.sub.3 gas which must be removed from the flue gas which
is normally discharged into the atmosphere.
Such metals and sulfur contaminants present similar problems with
regard to hydrocracking operations which are typically carried out
on chargestocks even lighter than those charged to a cracking unit,
and thus typically having an even smaller amount of metals present.
Hydrocracking catalyst is so sensitive to metals poisoning that a
preliminary or first stage is often utilized for trace metals
removal. Typical hydrocracking reactor conditions consist of a
temperature of 400.degree. to 1000.degree.F. and a pressure of 100
to 3500 psig.
In the past, and to a limited extent under present operating
schemes, high molecular weight stocks containing sulfur and metal
have often been processed in a coker to effectively remove metals
and also some of the sulfur, the contaminants remaining in the
solid coke. Coking is typically carried out in a reactor or drum
operated at about 800.degree. to 1100.degree.F. temperature and a
pressure of 1 to 10 atmospheres wherein heavy oils are converted to
lighter gas oils, gasoline, gas and solid coke. However, there are
limits to the amount of metals and sulfur that can be tolerated in
the product coke if it is to be saleable. Hence, there is
considerable need to develop economical as well as efficient means
for effecting the removal and recovery of metallic and non-metallic
contaminants from various fractions of petroleum oils so that
conversion of such contaminated charges to more desirable product
may be effectively accomplished. The present invention is
particularly concerned with the removal of metal contaminants from
hydrocarbon materials contaminated with the same. Also of concern
is the removal of sulfur contaminants from the contaminated
hydrocarbon fractions.
It has been proposed to improve the salability of high sulfur
content, residual-containing petroleum oils by a variety of
hydrodesulfurization processes. However, difficulty has been
experienced in achieving an economically feasible catalytic
hydrodesulfurization process, because notwithstanding the fact that
the desulfurized products may have a wider marketability, the
manufacturer may be able to charge little or no additional premium
for the low sulfur desulfurized products, and since
hydrodesulfurization operating costs have tended to be relatively
high in view of the previously experienced, relatively short life
for catalysts used in hydrodesulfurization of residual-containing
stocks. Short catalyst life is manifested by inability of a
catalyst to maintain a relatively high capability for desulfurizing
chargestock with increasing quantities of coke and/or metallic
contaminants which act as catalyst poisons. Satisfactory catalyst
life can be obtained relatively easily with distillate oils, but is
especially difficult to obtain when desulfurizing petroleum oils
containing residual components, since the asphaltene or asphaltic
components of an oil, which tend to form disproportionate amounts
of coke, are concentrated in the residual fractions of a petroleum
oil, and since a relatively high proportion of the metallic
contaminants that normally tend to poison catalysts are commonly
found in the asphaltene components of the oil.
An objective of this invention is to provide means for the removal
of metal and/or sulfur contaminants from petroleum oils. A further
objective of this invention is to provide means for the removal of
metal and/or sulfur contaminants from residual hydrocarbon
fractions. Another objective of this invention is to provide a
method whereby hydrocarbon fractions having a significant metal
and/or sulfur contaminant content may be demetalized in order to
produce suitable cracking, hydrocracking or coking unit
chargestock. An objective of this invention is to provide means for
the removal of sulfur contaminants from petroleum oils. A further
objective of this invention is to provide a method whereby
hydrocarbon fractions having a significant metal and/or sulfur
contaminant content may be demetalized in order to produce a
suitable fuel oil or fuel oil blend stock. Other and additional
objectives of this invention will become obvious to those skilled
in the art following a consideration of the entire specification
including the drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a curve showing the demetalation and desulfurization
ability of a catalyst of the class according to the present
invention as compared with another catalyst now used commercially
for demetalation and desulfurization.
FIG. 2 is a curve showing demetalation activity as a function of
temperature for a catalyst of the class of the present invention as
compared with another catalyst now used commercially for such a
process.
FIG. 3 is a curve showing desulfurization activity as a function of
temperature for a catalyst of the class of this invention as
compared with another catalyst now used commercially for such a
process.
FIG. 4 is a porosity profile of a catalyst of the class of this
invention.
FIG. 5 is an alumina phase diagram.
SUMMARY OF THE INVENTION
A hydrodemetalation-desulfurization class of catalysts comprising a
hydrogenating component (cobalt and molybdenum in a preferred
embodiment) composited with a refractory base (alumina in a
preferred embodiment), said composite catalyst having not less than
65 .+-. 10% of the volume of the pores having a diameter within the
range of about 180-300A and having a surface area of about 40 to
100 m.sup.2 /g has been discovered.
While not wishing to be bound by any particular theory of
operability, it is postulated that the utility of this invention's
catalyst is produced by the high concentration of pores within the
180-300A range.
A metal and/or sulfur containing hydrocarbon chargestock is
contacted with a catalyst of the class of this invention under a
hydrogen pressure of about 500 to 3000 psig and a hydrogen
circulation rate of about 1000 to 15,000 s.c.f./bbl of feed, and at
about 600.degree. to 850.degree.F. temperature and 0.1 to 5.0 LHSV.
When higher desulfurization is desired, the preferred operating
conditions are more severe: 725.degree. to 850.degree.F., a
hydrogen pressure of 2000 to 3000 and a space velocity of 0.10 to
1.5 LHSV.
Catalysts having a surface area of about 40 to about 100 m.sup.2 /g
performed well. A preferred surface area is 70 m.sup.2 /g or less.
FIG. 4 illustrates the porosity profile of a catalyst of the class
of applicants' invention. Such a profile is produced by plotting
the amount of a fluid (in this case mercury) in cc/g forced into
the pore structure as a function of pressure. As the pressure is
increased, the mercury is forced into smaller and smaller pores. As
is shown by curve 4, a dramatic increase in penetration with a
small pressure increase indicates that the structure has a large
number of pores within a particular size. The specific size is
determined by a standard capilliary tube equation calculation.
As illustrated in FIG. 1, a catalyst of such a class has the
ability to dramatically reduce metals content by as much as 98
percent, while also removing over 90 percent of the sulfur
contaminants.
As illustrated by FIG. 1, a catalyst of the class of this invention
has a strong selectivity for metals removal. Thus, a catalyst of
the type of this invention might well be employed with a second
catalyst having a high selectivity for sulfur removal, such as a
catalyst having at least about 50 percent of its pores in a 30A to
100A range. Optimum metals lay-down might be achieved by layering
the two catalysts, the 30A to 100A catalyst upstream of the
catalyst of this invention. The petroleum oils demetallized and
desulfurized by such a layered catalyst treatment would be
particularly useful as a cracking feedstock.
The catalyst is prepared by impregnating one or more hydrogenating
components on a suitable particulate matter refractory base, in a
preferred embodiment cobalt and molybdenum on a theta and/or delta
phase alumina base. A specific method of preparation is given in
Example 4. A particularly suitable particulate material for
demetalizing is one which has pores sufficiently large to permit
relatively unrestricted movement of the metal complex molecule in
and out of the pore as well as decomposition products thereof after
deposition of released metal. Solid porous particulate materials
which may be used with varying degrees of success for this purpose
include relatively large pore silica alumina and silica-magnesia
type compositions of little cracking activity, activated carbon,
charcoal, petroleum coke and particularly large pore aluminas or
high alumina ores and clays.
Clay supports of particular interest are those known as dickite,
halloysite and kaolinite. On the other hand, ores fitting the
herein provided physical properties either as existing in their
natural or original form or employed with alumina binders or after
chemical treatment thereof may also be used as porous support
materials in combination with the desired hydrogenation activity
herein discussed. By chemical treatment we intend to include acid
or caustic treatment as well as treatment with aqueous solutions
like sodium aluminate and alumina sulfate containing alumina to
increase the alumina content of the support.
The feedstock to be demetalized can be any metal contaminant
containing petroleum stock, preferably one containing residual
fractions. A process in accordance with the previously described
operating conditions is especially advantageous in connection with
chargestocks having a metals factor of greater than about 25.
From what has been said, it will be clear that the feedstock can be
a whole crude. However, since the high metal and sulfur components
of a crude oil tend to be concentrated in the higher boiling
fractions, the present process more commonly will be applied to a
bottoms fraction of a petroleum oil, i.e. one which is obtained by
atmospheric distillation of a crude petroleum oil to remove lower
boiling materials such as naphtha and furnace oil or by vacuum
distillation of an atmospheric residue to remove gas oil. Typical
residues to which the present invention is applicable will normally
be substantially composed of residual hydrocarbons boiling above
900.degree.F. and containing a substantial quantity of asphaltic
materials. Thus, the chargestock can be one having an initial or 5
percent boiling point somewhat below 900.degree.F., provided that a
substantial proportion, for example, about 40 or 50 percent by
volume, of its hydrocarbon components boil above 900.degree.F. A
hydrocarbon stock having a 50 percent boiling point of about
900.degree.F. and which contains asphaltic materials, 4 percent by
weight sulfur and 51 ppm nickel and vanadium is illustrative of
such chargestock. Typical process conditions may be defined as
contacting a metal and or sulfur contaminant containing chargestock
with this invention's catalyst under a hydrogen pressure of about
500 to 3000 psig, of 600.degree. to 850.degree.F. temperature, 0.1
to 5 LHSV.
The hydrogen gas which is used during the
hydrodemetalation-hydrodesulfurization is circulated at a rate
between about 1000 and 15,000 s.c.f./bbl of feed and preferably
between about 3000 and 8000 s.c.f./bbl. The hydrogen purity may
vary from about 60 to 100 percent. If the hydrogen is recycled,
which is customary, it is desirable to provide for bleeding off a
portion of the recycle gas and to add makeup hydrogen in order to
maintain the hydrogen purity within the range specified.
Satisfactory removal of hydrogen sulfide from the recycled gas will
ordinarily be accomplished by such bleed-off procedures. However,
if desired, the recycled gas can be washed with a chemical
absorbent for hydrogen sulfide or otherwise treated in known manner
to reduce the hydrogen sulfide content thereof prior to
recycling.
The invention is especially beneficial where the
hydrodemetalation-desulfurization is effected without concomitant
cracking of the hydrocarbons present in the feedstock. To achieve
this result, the temperature and space velocity are selected within
the ranges specified earlier that will result in the reduction of
the metals content of the feedstock of about 75 to 98 percent,
preferably over 90 percent.
The hydrogenating component of the class of catalysts disclosed
herein can be any material or combination thereof that is effective
to hydrogenate and desulfurize the chargestock under the reaction
conditions utilized. For example, the hydrogenating component can
be at least one member of the group consisting of Group VI and
Group VIII metals in a form capable of promoting hydrogenation
reactions, especially effective catalysts for the purposes of this
invention are those comprising molybdenum and at least one member
of the iron group metals. Preferred catalysts of this class are
those containing cobalt and molybdenum, but other combinations of
iron group metals and molybdenum such as iron, zinc, nickel and
molybdenum, as well as combinations of nickel and molybdenum,
cobalt and molybdenum, nickel and tungsten or other Group VI or
Group VIII metals of the Periodic Table taken singly or in
combination. The hydrogenating components of the catalysts of this
invention can be employed in sulfided or unsulfided form.
When the use of a catalyst in sulfided form is desired, the
catalyst can be presulfided, after calcination, or calcination and
reduction, prior to contact with the chargestock, by contact with
sulfiding mixture of hydrogen and hydrogen sulfide, at a
temperature in the range of about 400.degree. to 800.degree.F., at
atmospheric or elevated pressures. Presulfiding can be conveniently
effected at the beginning of an onstream period at the same
conditions to be employed at the start of such period. The exact
proportions of hydrogen and hydrogen sulfide are not critical, and
mixtures containing low or high proportions of hydrogen sulfide can
be used. Relatively low proportions are preferred for economic
reasons. When the unused hydrogen and hydrogen sulfide utilized in
the presulfiding operation is recycled through the catalyst bed,
any water formed during presulfiding is preferably removed prior to
recycling through the catalyst bed. It will be understood that
elemental sulfur or sulfur compounds, e.g. mercaptans, or carbon
disulfide that are capable of yielding hydrogen sulfide at the
sulfiding conditions, can be used in lieu of hydrogen sulfide.
Although presulfiding of the catalyst is preferred, it is
emphasized that this is not essential as the catalyst will normally
become sulfided in a very short time by contact, at the process
conditions disclosed herein, with the high sulfur content
feedstocks to be used.
The most relevant prior art discovered in the area is that of
Beuther et al., U.S. Pat. No. 3,383,301. That patent also deals
with demetalation and desulfurization and an alumina base catalyst
on which is composited a hydrogenating component, the pore volume
of the resultant catalyst having a particular pore size
distribution. However, the particular pore size distribution of
this disclosure is significantly different from that of Beuther.
Not only does that patent not teach or tend to lead one to the
catalyst characteristics of this invention, the Beuther et al.
disclosure basis of patentability is in fact contrary to that which
has been discovered.
While Beuther discloses a desulfurization catalyst "whose pore
volume is distributed over (a) wide range of pore sizes," it has
been discovered that a catalyst which has its pore volume
substantially concentrated in certain narrowly defined sizes
produces superior demetalation and desulfurization properties.
Beuther teaches that in order to attain such a wide range of pore
size, no more than 15 percent of the volume of the pores should be
present in any 10A radius incremental unit in the overall range of
0-300A radius. Not only does the catalyst which has here been
discovered have several 10A radius increments having greater than
15 percent of the pore volume, the catalyst has such large
percentage pore size increments adjacent to each other, thus
further distinguishing from Beuther's wide pore size range. The
catalyst of this invention has over 65 .+-. 10% of its pore volume
in the narrow range of 90-150A radius (180-300A diameter). The
catalyst of this invention may be further defined as having a
surface area of about 40 to 100 m.sup.2 /g, and preferably about 70
m.sup.2 /g or less, and an average pore diameter of about 200A to
400A diameter. Other somewhat less relevant patents in this general
area are listed as follows: Anderson (U.S. Pat. No. 2,890,162);
Erickson (U.S. Pat. No. 3,242,101); Bertolacini (U.S. Pat. No.
3,393,148); Roselinus (U.S. Pat. No. 3,684,688); Bertolacini (U.S.
Pat. No. 3,714,032) and Christman (U.S. Pat. No. 3,730,879). None
of these patents teach the particular pore distribution of this
disclosure.
While not wishing to be bound by any particular theory of
operability, it is felt that the uniqueness of this invention's
catalyst is at least partially due to the fact that the alumina
catalyst base is calcined to a particular temperature thereby
producing a specific alumina. It is felt that it is this phase
which produces the distinct pore size distribution of the catalyst.
The particular method of preparation of the catalyst of this
invention is explained in detail in Example 4.
As noted in Alumina Properties p. 46 by Newsome, Heiser, Russel and
Stumpf (Alcoa Research Laboratories, 1960), the theta alumina phase
may only be reached through employing an alpha monohydrate or a
beta trihydrate alumina form. Calcining temperatures required to
achieve the theta phase vary depending on which alumina form is
utilized as the initial alumina. An alpha monohydrate enters the
gamma phase at about 500.degree.C., crosses the transition point
into the delta phase at about 860.degree.C. and enters the narrowly
temperature banded theta phase at about 1060.degree.C. The
transition point between theta and alpha phases being at about
1150.degree.C.
When utilizing a beta trihydrate as an initial alumina, the theta
phase is broader, its limits being about 860.degree.C. to about
1160.degree.C. It should be noted that both beta trihydrate and
alpha trihydrate aluminas may also be transformed into the alpha
monohydrate form. The alumina phase diagram is presented in FIG.
6.
DESCRIPTION OF SPECIFIC EMBODIMENTS
Examples 1-3
In these specific embodiments, two catalysts representative of the
class disclosed herein (Examples 2 and 3) were prepared by
cobalt-molybdenum deposition on alumina as further described in
Example 4. These catalysts were then tested for demetalation and
desulfurization ability. Both the physical characteristics of these
catalysts and the demetalation-desulfurization activity results are
shown in Table 1 as compared with the characteristics and activity
of a commercial catalyst (Example 1).
The operating conditions for each of the Examples 1-3 comprised
2000 psig hydrogen pressure, 0.75 LHSV space velocity,
725.degree.F., and 5000 s.c.f. H.sub.2 /bbl of residual fraction
(Kuwait Atmospheric Residua having 3.54% by weight sulfur, 12 ppm
Ni and 42 ppm V).
FIGS. 1, 2 and 3 as previously described represent a comparison of
the activity of demetalation and desulfurization of Example 1, a
catalyst now being used commercially and Example 2, a catalyst of
the class of this invention.
Example 4
A preparation procedure for the demetalation-desulfurization class
of catalysts of this invention may be defined as follows:
1400 grams of catapal SB alumina was aged in about 700 grams of
water for about 16 hours at about 200.degree.F. The mixture of
alumina was then mixed with a mechanical mixer for about 15
minutes. The alumina was then extruded through a 1/32 inch diameter
auger extruder and dried thoroughly at about 250.degree.F.
The alumina was then calcined with a dry air flow at a rate of
about 2.degree.F/minute up to a temperature of about
1000.degree.F., that temperature being held constant for about 10
hours. The alumina was next calcined for 2 hours at about
1950.degree.F., the temperature being increased as rapidly as
possible and without an air flow.
Water was added to about 91.8 grams of ammonium molybdate solution
(81.9 purity) until a total volume of about 260 grams was reached.
This solution was then placed under vacuum with the alumina.
Following this vacuum impregnation step, the alumina was dried at
about 250.degree.F.
Finally, the 585 grams of molybdenum impregnated alumina was
impregnated under vacuum with about 76.2 grams of CoCl.sub.
2.6H.sub.2 O diluted in water to a total volume of about 176 ml.
The cobalt molybdenum impregnated alumina was then dried at
250.degree.F. and calcined by heating to a temperature of about
1000.degree.F. at a rate of about 3.degree.-4.degree.F/minute and
held at that temperature for about 10 hours.
TABLE 1
__________________________________________________________________________
PROPERTIES AND ACTIVITY OF RESID HYDROPROCESSING CATALYSTS
__________________________________________________________________________
Example Number 1 2 3 Catalyst CATALYST A SMo-8056 SMo-8051
__________________________________________________________________________
Description CoMo/Al.sub.2 O.sub.3 CoMo/Al.sub.2 O.sub.3
CoMo/Al.sub.2 O.sub.3 Size 1/32 inch 1/32 inch 1/32 inch Properties
Surface Area, m.sup.2 /g 286 70 69 Pore Volume, cc/g 0.491 0.625
0.359 Ave. Pore Diam, A 69 357 208.1 Crush Strength, No./in. 76 50
-- Pore Size Dist, % of Total Pore Vol. (According to pore Diam in
A.degree.) 500 + 2.2 5.1 2.5 500 - 400 0.0 2.1 0.3 400 - 300 0.0
11.7 0.6 300 - 240 0 33.9 2.5 240 - 220 0 12.8 3.9 220 - 200 0 8.0
43.7 200 - 180 0 5.1 24.5 180 - 160 0 3.8 8.4 160 - 140 0.2 2.2 5.6
140 - 120 0.2 1.6 4.2 120 - 100 1.0 1.3 2.8 100 - 80 1.0 1.0 1.1 80
- 60 76.4 1.4 0.0 60 - 40 6.9 1.8 0.0 40 - 0 12.0 8.2 0.0 Activity
Desulfurization, wt. % 85 77 76 Demetalation, wt. % 57 94 71
H.sub.2 Consumption, SCF/B 600 420 510
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