U.S. patent number 3,716,479 [Application Number 05/100,931] was granted by the patent office on 1973-02-13 for demetalation of hydrocarbon charge stocks.
This patent grant is currently assigned to Mobil Oil Corporation. Invention is credited to Anthony J. Silvestri, Paul B. Weisz.
United States Patent |
3,716,479 |
Weisz , et al. |
February 13, 1973 |
DEMETALATION OF HYDROCARBON CHARGE STOCKS
Abstract
This specification discloses the demetalation of a hydrocarbon
charge stock. The demetalation procedure involves contacting the
hydrocarbon charge stock with hydrogen in the presence of, as a
catalyst, a material derived from the naturally-occurring
underwater deposit known as a manganese nodule. The manganese
nodule may be employed without pretreatment or may be pretreated by
sulfiding or by leaching to remove and recover one or more valuable
metallic constituents. The manganese nodule catalyst, after it has
become deactivated by use, may be processed to remove and recover
one or more valuable metallic constituents.
Inventors: |
Weisz; Paul B. (Yardley,
PA), Silvestri; Anthony J. (Morrisville, PA) |
Assignee: |
Mobil Oil Corporation
(N/A)
|
Family
ID: |
22282266 |
Appl.
No.: |
05/100,931 |
Filed: |
December 23, 1970 |
Current U.S.
Class: |
208/211;
423/DIG.4; 208/251H; 502/324 |
Current CPC
Class: |
B01J
23/34 (20130101); B01J 37/06 (20130101); C10G
2300/107 (20130101); Y10S 423/04 (20130101) |
Current International
Class: |
C10G
45/02 (20060101); B01J 23/34 (20060101); B01J
23/16 (20060101); B01J 37/00 (20060101); B01J
37/06 (20060101); C10G 69/04 (20060101); C10G
65/00 (20060101); C10G 69/00 (20060101); C10G
45/04 (20060101); C10G 65/04 (20060101); C10g
023/02 () |
Field of
Search: |
;208/251,253,211,208,209,213,249,295,298,299,210,110 ;252/471,454
;75/115 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Coughlan, Jr.; Paul M.
Assistant Examiner: Crasanakis; G. J.
Claims
We claim:
1. A process for the demetalation of a hydrocarbon charge stock
containing metal impurities comprising contacting said hydrocarbon
charge stock with hydrogen and with a catalyst comprising the
naturally-occurring, underwater deposit known as manganese
nodules.
2. The process of claim 1 wherein said catalyst is a manganese
nodule which contains copper, nickel or molybdenum in its
composition and which has had at least a portion of its copper,
nickel or molybdenum content removed therefrom.
3. The process of claim 2 wherein said at least a portion of its
copper or nickel content has been removed from said manganese
nodule by leaching said manganese nodule with an aqueous solution
of acid.
4. The process of claim 2 wherein said at least a portion of its
molybdenum content has been removed from said manganese nodule by
leaching said manganese nodule with an aqueous solution of a
base.
5. The process of claim 4 wherein said aqueous solution of a base
has a pH of at least 8.
6. The process of claim 4 wherein said aqueous solution of a base
has a pH of at least 10.
7. The process of claim 1 wherein said catalyst is obtained by
contacting said manganese nodules with hydrogen sulfide.
8. The process of claim 7 wherein said manganese nodules are
contacted with said hydrogen sulfide at a temperature from about
300.degree. F. to about 450.degree. F.
9. The process of claim 7 wherein said manganese nodules are
contacted with said hydrogen sulfide for a time from about 4 hours
to about 8 hours.
10. The process of claim 7 wherein said manganese nodules are
contacted with said hydrogen sulfide at a temperature from about
300.degree. F. to about 450.degree. F. and for a time from about 4
hours to about 8 hours.
11. The process of claim 1 wherein said charge stock and said
hydrogen are contacted with said catalyst at a temperature from
about 650.degree. F. to about 850.degree. F.
12. The process of claim 1 wherein said charge stock and said
hydrogen are contacted with said catalyst at a temperature of
750.degree.-850.degree. F.
13. The process of claim 1 wherein said charge stock and said
hydrogen are contacted with said catalyst at a pressure from about
100 to about 3,000 pounds per square inch gage.
14. The process of claim 1 wherein said charge stock and said
hydrogen are contacted with said catalyst at a pressure of
500-2,000 pounds per square inch gage.
15. The process of claim 1 wherein said charge stock and said
hydrogen are contacted with said catalyst at a temperature from
about 650.degree. F. to about 850.degree. F. and at a pressure from
about 100 to about 1,000 pounds per square inch gage.
16. The process of claim 1 wherein said charge stock and said
hydrogen are contacted with said catalyst by passing said charge
stock through a bed of said catalyst.
17. The process of claim 16 wherein said charge stock is passed
through said bed of catalyst at a rate from about 0.2 to about 4
volumes of charge stock per volume of catalyst per hour.
18. The process of claim 16 wherein said charge stock is passed
through said bed of material at a rate from about 0.5 to about 2
volumes of charge stock per volume of material per hour.
19. The process of claim 16 wherein the circulation rate of said
hydrogen is 2,000-15,000 standard cubic feet of hydrogen per barrel
of charge stock.
20. The process of claim 16 wherein the circulation rate of said
hydrogen is 5,000-10,000 standard cubic feet of hydrogen per barrel
of charge stock.
21. The process of claim 16 wherein said charge stock is passed
through said bed of catalyst at a rate from about 0.2 to about 4
volumes of charge stock per volume of catalyst per hour and the
circulation rate of said hydrogen is 2,000-15,000 standard cubic
feet of hydrogen per barrel of charge stock.
22. A process for the demetalation of a hydrocarbon charge stock
containing metal impurities comprising contacting said hydrocarbon
charge stock with hydrogen at a temperature from about 650.degree.
F. to about 850.degree. F. and at a pressure from about 100 to
about 3,000 pounds per square inch gage and with a catalyst
comprising a manganese nodule which has been previously contacted
with hydrogen sulfide at a temperature from about 300.degree. F. to
about 450.degree. F. and for a time from about 4 hours to about 8
hours.
23. A process which comprises demetalizing a hydrocarbon charge
stock containing metal impurities by contacting said hydrocarbon
charge stock with hydrogen and with a catalyst comprising the
naturally-occurring, underwater deposit known as manganese nodules
and desulfurizing the demetallized hydrocarbon charge stock by
contacting said demetallized hydrocarbon charge stock with hydrogen
and with a desulfurizing catalyst under hydrodesulfurizing
conditions.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the treatment of a hydrocarbon charge
stock and relates more particularly to the treatment of a
hydrocarbon charge stock to effect removal therefrom of
organo-metallic compounds.
2. Description of the Prior Art
U.S. Pat. No. 3,214,236 discloses hydrogenation, desulfurization
and denitrogenation as being conversion processes in which
manganese nodules are catalytically useful. This patent also
discloses that the manganese nodule catalyst can be a source of
manganese and other valuable metals after being spent in effecting
the desired catalytic conversion.
U.S. Pat. No. 3,509,041 discloses the use of manganese nodules,
after pretreatment by base exchange to bond hydrogen ions thereto,
in hydrocarbon conversion reactions, specifically cracking,
hydrocracking, oxidation, olefin hydrogenation, and olefin
isomerization.
U.S. Pat. No. 3,330,096 discloses the use of manganese nodules for
removing sulfur compounds from gases.
U.S. Pat. No. 3,471,285 discloses the selective separation of
manganese and iron from manganese nodules which also contain cobalt
and nickel by reducing the nodules at elevated temperatures and
then leaching with an aqueous solution of ammonium sulfate.
SUMMARY OF THE INVENTION
In accordance with the invention, a hydrocarbon charge stock is
demetalized by contacting the charge stock with hydrogen, in the
presence of, as a catalyst, a material derived from the
naturally-occurring underwater deposit known as a manganese nodule.
In accordance with a specific embodiment of the invention, the
manganese nodule is employed without pretreatment. In accordance
with other specific embodiments of the invention, the manganese
nodule may be pretreated by sulfiding, or by leaching to remove one
or more metallic constituents, or by any combination of the
pretreating procedures. In accordance with still another embodiment
of the invention, the catalyst, after becoming deactivated by use,
is treated to remove and recover therefrom one or more metallic
constituents.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 of the accompanying drawings are photomicrographs of
the surfaces of the manganese nodules.
FIG. 3 is a flow diagram illustrating a procedure wherein
demetalation of a hydrocarbon charge stock is carried out and the
charge stock is then processed for sulfur and/or nitrogen
removal.
FIG. 4 is a flow diagram illustrating a procedure wherein
demetalation of a hydrocarbon charge stock is carried out and the
charge stock is then subjected to catalytic cracking. pg,4
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various hydrocarbon charge stocks such as crude petroleum oils,
topped crudes, heavy vacuum gas oils, shale oils, oils from tar
sands, and other heavy hydrocarbon fractions such as residual
fractions and distillates contain varying amounts of non-metallic
and metallic impurities. The non-metallic impurities include
nitrogen, sulfur, and oxygen and these exist in the form of various
compounds and are often in relatively large quantities. The most
common metallic impurities include iron, nickel, and vanadium.
However, other metallic impurities including copper, zinc, and
sodium are often found in various hydrocarbon charge stocks and in
widely varying amounts. The metallic impurities may occur in
several different forms as metal oxides or sulfides which are
easily removed by single processing techniques such as by
filtration or by water washing. However, the metal contaminants
also occur in the form of relatively thermally stable
organo-metallic complexes such as metal porphyrins and derivatives
thereof along with complexes which are not completely identifiable
and which are not so readily removed.
The presence of the metallic impurities in the hydrocarbon charge
stocks is a source of difficulty in the processing of the charge
stocks. The processing of the charge stock, whether the process is
desulfurizing, cracking, reforming, isomerizing, or otherwise, is
usually carried out in the presence of a catalyst and the metallic
impurities tend to foul and inactivate the catalyst to an extent
that may not be reversible. Fouling and inactivation of the
catalyst are particularly undesirable where the catalyst is
relatively expensive, as, for example, where the active component
of the catalyst is platinum. Regardless of the cost of the
catalyst, fouling and inactivation add to the cost of the
processing of the charge stock and therefore are desirably
minimized.
Demetalation of the hydrocarbon charge stock can be effected by
thermal processing of the charge stock. However, thermal processing
results in conversion of an appreciable portion of the charge stock
to coke and the portion of the charge stock converted to coke
represents a loss of charge stock that desirably should be
converted to a more economically valuable product or products.
Moreover, by thermal processing, the metallic impurities tend to
deposit in the coke with the result that the coke is less
economically desirable than it would be in the absence of the
metals.
Demetalation can also be effected by catalytic hydroprocessing of
the charge stock. However, catalytic hydroprocessing results in the
catalyst becoming fouled and inactivated by deposition of the
metals on the catalyst. There is no convenient way of regenerating
the catalyst and it ultimately must be discarded. Since these
catalysts are relatively expensive, catalytic hydroprocessing to
demetalize hydrocarbon charge stocks has suffered from adverse
economics.
By the process of the invention, an economical and effective
demetalation of a hydrocarbon charge stock is obtained. Manganese
nodules are readily available in large quantities and are
relatively inexpensive. Further, material derived from the nodules
is capable of effectively removing the metallic impurities from a
hydrocarbon charge stock. Thus, whereas the material obtained from
the manganese nodules becomes fouled and inactivated by the
demetalizing process, the material is obtainable at such low cost
that the fouled and inactivated material can be discarded without
significant effect on the economics of the demetalizing
process.
Manganese nodules, as is known, are naturally occurring deposits of
manganese, along with other metals, including iron, cobalt, nickel,
and copper, found on the floor of bodies of water. They are found
in abundance on the floors of oceans and lakes. For example, they
are found in abundance on the floor of the Atlantic and Pacific
Oceans and on the floor of Lake Michigan. The nodules are
characterized by a large surface area, i.e., in excess of 150
square meters per gram. The nodules have a wide variety of shapes
but most often those from the oceans look like potatoes. Those from
the floor of bodies of fresh water, such as the floor of Lake
Michigan, tend to be smaller in size. Their color varies from
earthy black to brown depending upon their relative manganese and
iron content. The nodules are porous and light, having an average
specific gravity of about 2.4. Generally, they range from
one-eighth inch to 9 inches in diameter but may extend up to
considerably larger sizes approximating 4 feet in length and 3 feet
in diameter and weighing as much as 1,700 pounds. In addition to
the metals mentioned above, the modules contain silicon, aluminum,
calcium and magnesium, and small amounts of molybdenum, zinc, lead,
vanadium, and rare earth metals.
The chemical and physical properties of manganese nodules, as
catalytic agents for the demetalation of hydrocarbon charge stocks,
are, as compared with conventional catalytic agents for this
purpose, considered to be somewhat unusual. The nodules have a high
surface area, about 100-250 square meters per gram. They will,
however, lose surface area by metal deposition during the
demetalation reaction. Further, as shown by Roger G. Burns and D.
W. Fuerstenau in American Mineralogist, Vol. 51, 1966, pages
895-902, "Electron-Probe Determination of Inter-Element
Relationships in Manganese Nodules", the concentrations of the
various metals contained in the nodules, i.e., the manganese, iron,
cobalt, copper, and nickel, are not uniform throughout the
crystalline structure of the nodule. Rather, a traverse across a
section of a nodule will show marked differences in the
concentrations of the various metals from point to point of the
traverse. However, there appears to be a correlation between the
concentrations of iron and cobalt. On the other hand, manufactured
catalysts for demetalation are usually as uniform as the
manufacturer can achieve.
The accompanying figures illustrate the structure of manganese
nodules. These nodules were obtained from the Blake Plateau in the
Atlantic Ocean. Each of FIGS. 1 and 2 is a photomicrograph of a
surface of the nodules, FIG. 1 showing more of the pore system than
FIG. 2. Magnifications in each figure are 150.times..In each of the
figures, the large dark areas are large pores. The light- and
dark-banded regions are solid material. The nodules are formed by
slow deposition of colloidal materials. The composition of the
particles of the colloidal materials varies with time resulting in
the microscopic stratification and inhomogeneity shown in the
figures.
The manganese nodules can be employed as the catalyst for the
demetalation of the hydrocarbon charge stock substantially as
mined, or recovered, from the floor of the body of water in which
they occurred. Thus, the nodules, as mined, possibly after washing
to remove sea water or lake water therefrom and mud or other loose
material from the surface of the nodules, may be employed for
demetalation.
The demetalation reaction may also be carried out employing, as the
catalyst, manganese nodules which have been subjected to a
pretreatment. Pretreatments to which the manganese nodules may be
subjected include sulfiding or leaching to remove therefrom one or
more components of the nodules.
Sulfiding of the manganese nodules increases the extent of
demetalizing of the charge stock. It also can increase the extent
of desulfurization and Conradson Carbon Residue (CCR) reduction,
each of which is desirable. This treatment is carried out by
contacting the nodules with hydrogen sulfide. The hydrogen sulfide
may be pure or may be mixed with other gases. However, the hydrogen
sulfide should be substantially free of hydrogen. The temperature
of sulfiding may be from about 300.degree. F. to about 450.degree.
F. and the time of sulfiding may be from about 4 to about 8 hours.
The sulfiding may be effected, for example, by passing the hydrogen
sulfide over the manganese nodules continuously during the
sulfiding reaction. The space velocity of the hydrogen sulfide is
not critical and any space velocity compatible with the equipment
and such that some hydrogen sulfide is continuously detected in the
exit stream is suitable.
The manganese nodules may also be pretreated by being subjected to
leaching to remove therefrom one or more components. As mentioned
previously, the manganese nodules contain, in addition to
manganese, copper, nickel, and molybdenum. They may be pretreated
to leach therefrom the copper, nickel, or molybdenum, or any two,
or all three, of these metals. The manganese nodules contain the
copper, nickel, and molybdenum in sufficient quantities to provide
a commercial source of these metals. Further, the removal, at least
partially, of these metals and other of the metallic constituents
of the nodules has apparently no effect on the catalytic activity
of the nodules for demetalation of hydrocarbon charge stocks. Thus,
by this embodiment of the invention, copper, nickel, and
molybdenum, and other metals, may be recovered from the nodules for
the economic advantage to be gained by such recovery and the
remainder of the manganese nodules can then be employed as a
catalyst for demetalation of hydrocarbon charge stocks.
Removal of the copper and the nickel may be effected by leaching
the manganese nodules with an aqueous solution of a strong acid. By
strong acid is meant such acids as hydrochloric, sulfuric, and
nitric acids.
The molybdenum may be removed from the manganese nodules by
leaching them with aqueous base solutions such as aqueous solutions
of sodium hydroxide or sodium carbonate. These solutions should
have a pH of at least 8 and preferably should have a pH of at least
10. The leaching with the aqueous base solutions can be carried out
at ambient temperatures or at the boiling point of the
solution.
The nodules, with or without pretreatment, may be crushed and sized
to obtain a desired particle size depending upon the type of
demetalation operation employed, for example, a fixed bed
operation, an ebullition operation or otherwise.
The demetalation reaction is carried out by contacting the
hydrocarbon charge stock simultaneously with the catalyst and with
hydrogen. The temperatures at which the reaction is carried out can
be from about 650.degree. F. to about 850.degree. F. At the higher
temperatures, a greater degree of demetalation occurs. However, the
temperatures employed should not be so high as to effect an
undesirable degree of alteration of the charge stock. Preferably,
the temperatures employed are in the range of
750.degree.-850.degree. F. The pressures at which the reaction is
carried out can be from about 100 to about 3,000 pounds per square
inch gage (psig). Preferably, the pressures employed are in the
range of 500-2,000 psig. Where the reaction is carried out by
passing the hydrocarbon charge stock through a bed of the catalyst,
the liquid hourly space velocity (LHSV) of the charge stock can be
from about 0.2 to 4, preferably 0.5 to 2, volumes of charge stock
per volume of catalyst per hour. Hydrogen circulation is at rates
of 2,000-15,000, preferably 5,000-10,000, standard cubic feet of
hydrogen per barrel of hydrocarbon charge stock. The hydrocarbon
charge stock along with the hydrogen may be passed upwardly through
a fixed bed of the catalyst in an upflow reactor or may be passed
downwardly through a fixed bed of the catalyst in a downflow
trickle-bed reactor. The reaction may also be carried out by
passing the charge stock and the hydrogen through an ebullient bed
of the catalyst. The reaction may also be carried out by contacting
the charge stock, the hydrogen, and the catalyst in a batch
reactor.
The catalyst, after being employed in the demetalation reaction and
having become catalytically deactivated, or spent, can be treated
for the recovery therefrom of valuable metals. Thus, the catalyst,
after becoming spent, may be treated to recover copper, nickel,
molybdenum, or any two, or all three, of these metals. It may also
be treated to recover therefrom any other component.
An advantage of the process of the invention resides in its economy
with respect to hydrogen consumption. During the demetalation
reaction, hydrogen is consumed and the consumption of the hydrogen
adds to the cost of demetalation. Thus, reduction in the
consumption of the hydrogen is economically desirable. Prior
processes directed to demetalation have often required consumption
of hydrogen in amounts between about 450 and 1,000 cubic feet per
barrel of hydrocarbon charge stock. As compared to this, by the
process of the invention, effective demetalation can be effected in
many instances with consumption of 50 to 300 cubic feet of hydrogen
per barrel of hydrocarbon charge stock.
While we do not wish to be limited to the consequences of any
theory, it is believed that the reduced hydrogen consumption to a
large extent is due to the sensitivity of the manganese nodules to
the effects of sulfur. Manganese nodules, as well as other
catalysts heretofore employed for the demetalation of hydrocarbon
charge stocks, effect hydrogenation of molecules other than those
containing metals. Thus, the manganese nodules, as well as other
demetalation catalysts, will effect hydrogenation of benzene rings,
for example. This hydrogenation of molecules other than those
containing metals therefore results in consumption of the hydrogen
in addition to that related to demetalation and, from the
standpoint of the desired demetalation, represents a waste of
hydrogen. However, as contrasted with other demetalation catalysts,
the manganese nodules, in the presence of sulfur, have essentially
no activity for hydrogenating benzene and other aromatic molecules.
They will, however, hydrogenate olefins. Hydrocarbon charge stocks
contain sulfur to a greater or lesser extent, and, regardless of
whether the catalyst is subjected to a sulfiding pretreatment, the
sulfur in the hydrocarbon charge stocks will effect a rapid
sulfiding of the nodules. As a result, hydrogenation of the
aromatic constituents of the charge stock is reduced with resulting
reduction in the consumption of the hydrogen.
Whereas a rapid sulfiding of the nodules will occur from the sulfur
in the hydrocarbon charge stocks, sulfiding pretreatment of the
nodules, as previously described, is of value. It is believed that,
under reducing conditions, a reduction of the metal oxides in the
nodules can occur with consequent loss in surface area and
diminished activity. The sulfides on the other hand are more stable
to reduction. Thus, when the nodules are exposed to a reducing
environment either before or during sulfiding as occurs when the
sulfiding results from the sulfur in the charge stock, a
prereduction or competitive reduction of the oxides can take
place.
The process of the invention may be employed for the demetalation
of any hydrocarbon charge stock containing organo-metallic
compounds. Ordinarily, these will be hydrocarbon charge stocks
containing sufficient metal to cause difficulty in the processing,
or other subsequent use, of the charge stocks. Other subsequent use
of the charge stocks can include burning of the charge stock as
fuel wherein the metals cause corrosion problems. These charge
stocks include whole crude petroleum oils, topped crude oils,
residual oils, distillate fractions, heavy vacuum gas oils, shale
oils, oils from tar sands, and other heavy hydrocarbon oils. Charge
stocks derived from Mid-Continent and East Texas crudes contain
small amounts of metals. For example, some East Texas crudes
contain about 0.1 part per million of vanadium and 2-4 parts per
million of nickel. Charge stocks derived from West Texas crudes and
foreign crudes, however, can contain larger amounts of metal.
Kuwait crude can contain over 32 parts per million of vanadium and
over 9 parts per million of nickel while Venezuelan crudes can
contain 200-400 parts per million of vanadium and 17 to 59 parts
per million of nickel.
The process of the invention can be carried out in conjunction with
subsequent steps of processing of the hydrocarbon charge stock. For
example, the hydrocarbon charge stock can be subsequently processed
for removal of sulfur and/or nitrogen. Further, for example, the
hydrocarbon charge stock can be subsequently processed by catalytic
cracking.
Concerning processing of the hydrocarbon charge stock for removal
of sulfur and/or nitrogen subsequent to demetalation employing
manganese nodules, this represents an operation in which economies
are effected by employing an inexpensive catalyst in the first step
to increase the life of a relatively expensive catalyst in the
subsequent step. For sulfur and/or nitrogen removal, relatively
expensive manufactured catalyst, particularly suited for this
purpose, is employed. The prior removal of a significant fraction
of the metals by the manganese nodules will reduce the
deterioration of the more expensive manufactured catalyst by
poisoning from the metals in the charge stock and lead to extended
life of the more expensive catalyst. The processing sequence is
unique in that the overall results are not mere additive results of
the steps; catalyst life of the desulfurization catalyst is
modified by the presence of the nodules, while the nodules perform
a dual function of both demetalation and partial
desulfurization.
The desulfurization catalyst suitable for use in such a combination
process is broadly characterized as any hydrogenation catalyst
which is tolerant of sulfur and nitrogen and which can be employed
in an operating cycle or onstream life that is economically
attractive. Thus, the desulfurization and/or denitrogenation
catalyst may be any one of those known and used for such purposes
in the prior art. Prominent catalysts used for this purpose include
cobalt molybdate on alumina with or without small amounts of
silica, nickel sulfide, tungsten sulfide, and nickel-tungsten
sulfide alone or on a support material such as alumina which may or
may not contain small amounts of combined silica. Other suitable
and known desulfurization catalysts may also be employed.
To facilitate an understanding of the described combination
process, reference will now be had to FIG. 3. In the arrangement of
FIG. 3, a relatively heavy hydrocarbon feed such as a residual oil
containing sulfur and metal contaminants is introduced to the
process through line 10 to furnace 11 wherein the hydrocarbon feed
is heated to an elevated temperature in the range of from about
650.degree. F. to about 850.degree. F. The hydrocarbon feed may be
heated either alone or in combination with hydrogen rich gas
supplied through line 12, it being preferred to mix the hydrogen
rich gas with the feed prior to being heated in the furnace.
Thereafter, the heated mixture is introduced through line 13 to
demetalation reactor 14. Make-up fresh catalyst may be added with
the hydrocarbon feed through line 15 or directly to the
demetalation reactor. The demetalation reactor can be operated
under liquid phase conditions wherein finely divided manganese
nodules are added to and maintained in suspended motion by the
liquid hydrocarbon flowing upwardly through the demetalation
reactor. The rate of flow of the liquid feed upwardly through the
demetalation reactor in this type of operation is sufficiently high
to suspend the catalyst particles in a fairly random movement. The
technique of causing random movement of particulate material by the
upward flow of the liquid has been identified with the prior art as
ebullition. The demetalation of the feed may also be accomplished
in a dense fluid bed of solid particulate material, a moving bed
operation, or other convenient means for effecting demetalation
where the solid particulate material can be replaced as required
after becoming spent.
The liquid hydrocarbon leaves the upper portion of the demetalation
reactor through line 20. Hydrogen gas is purged from the upper
portion of the demetalation reactor through line 21. A portion of
this gas may be recycled to the demetalation reactor through line
22 provided with pump 23 and connected to line 12. Make-up hydrogen
can be provided through line 24, also connected to line 12, if
make-up hydrogen gas is required. At the level at which the
hydrocarbon leaves the demetalation reactor, the hydrocarbon may
contain catalyst fines and a fines separator 25 is provided. The
fines separator may be a cyclone separator, filter arrangement, or
any other convenient means for separating the entrained fines from
the withdrawn liquid material. Liquid material is withdrawn from
the fines separator through line 30 provided with pump 31 and
passed on for further processing. If desired, intermediate
fractionation, not shown, can be provided.
Spent fines, having relatively high concentrations of deposited
metals therein of nickel, vanadium, copper and iron, may be
withdrawn from the lower portion of the demetalation reactor
through line 32.
Demetalation in the reactor will be carried out under the
conditions previously mentioned, i.e., temperature within the range
of from about 650.degree. F. to 850.degree. F., a pressure within
the range of 100 to 3,000 psig, and a space velocity within the
range of 0.2 to about 4. Some desulfurization of the charge will
also be accomplished during demetalation but will be less effective
than desired to be accomplished in the second step of the
process.
In the second step of the process, the hydrocarbon charge recovered
from the demetalation reactor, and in which the metals level has
been significantly reduced, is then subjected to catalytic
hydrodesulfurization. For this purpose, the hydrocarbon charge is
passed to furnace 33 and thence through lines 34 and 35 to
desulfurization reactor 36. Hydrogen make-up is provided through
line 40. Catalytic hydrodesulfurization of sulfur-bearing
hydrocarbon charge material has been known and practiced in the
petroleum refining art for years. Generally speaking, satisfactory
desulfurization results are obtained when operating at a
temperature in the range of from about 650.degree. F. to about
850.degree. F. and a pressure in the range of about 500 to about
3,000 psig when employing a space velocity in the range of about 3.
Suitable catalysts have already been described above.
In the desulfurization reactor, the desulfurization zone comprises
a fixed catalyst bed through which the hydrocarbon charge is passed
downwardly under desulfurizing conditions. Other types of
desulfurization contact zones may be employed such as the trickle
process or an ebullating bed of catalyst. In the arrangement shown,
the hydrocarbon charge, in admixture with hydrogen rich gas in
suitable proportions, is caused to move, after suitable heating
thereof in the furnace, downwardly through the bed of catalyst
under desulfurizing conditions. The effluent is removed from the
lower portion of the reactor through line 41 and passed to a
separator 42. In the separator, a gasiform stream is separated from
a normally liquid product stream. The gasiform stream comprising
hydrogen, low boiling hydrocarbon, and compounds of sulfur and
nitrogen is removed from the upper portion of the separator through
line 43. This gasiform stream may be treated to produce a hydrogen
rich stream by any one of a number of known techniques and the thus
produced hydrogen rich stream recycled through line 35 for
admixture with the hydrocarbon charge to be desulfurized. The
remainder of the gasiform stream is purged from the system through
line 45. Desulfurized product is removed from the separator through
line 46.
It is contemplated having more than one desulfurization zone in
sequence in which the latter zone or zones, depending on the number
employed, will be employed to effect substantial denitrogenation of
the hydrogen charge when required. Thus the process contemplates a
third catalytic contact zone (not shown) for effecting more
complete desulfurization and/or denitrogenation of the hydrocarbon
charge in which case the third zone may be placed after the
separator.
Concerning processing of hydrocarbon charge stock by catalytic
cracking subsequent to demetalation, metal poisoning of the
catalysts employed for cracking can lead to severe problems such as
low gas density due to the formation of hydrogen, higher gas make,
and lowered gasoline yields. This problem is generally circumvented
by controlling the allowable metals content of the feed stock to
the cracking unit. However, this restriction also limits the
percentage of crude which can provide suitable feed stock to a
cracking unit.
Metals content of a catalytic cracking stock is often expressed in
terms of a metals factor which is defined as parts per million
(ppm) Fe + ppm V + 10 times the ppm Ni + 10 times the ppm Cu. In
general, for satisfactory performance of a catalytic cracking unit,
the metals factor of the feed stock should be limited to about 5.
The invention allows the use of a process complex which includes
demetalation which removes, for example, 90 percent of the metals;
thus the metals factor of the feed stock to this catalytic
processing complex can now be as high as 50. This in turn will
significantly increase the percentage of crude which provides an
acceptable feed stock for catalytic cracking. This processing
combination is accomplished by distillation separation of a charge
stock into a lighter and a heavier metals rich portion,
demetalation of the heavier portion, and feeding the demetalized
effluent to the catalytic cracking unit; all or part of the lighter
portion would preferably be fed to the same catalytic cracking
unit.
Reference will now be had to FIG. 4. The hydrocarbon charge stock,
i.e., crude oil, is brought into an atmospheric pressure still 50
through line 51. Light gases are removed from the still through
line 52 while the fraction boiling between the light gases and
400.degree. F. is removed through line 53. The
400.degree.-600.degree. F. material from this still is used for
catalytic cracking and is passed through lines 54 and 55 to
catalytic cracking unit 60. The bottoms from the atmospheric still
are passed through line 61 on to a vacuum still 62. The overhead
from the vacuum still is passed through line 63 along with hydrogen
to a demetalation reactor 64, while the bottoms will generally be
passed through line 65 to thermal processing. The effluent from the
demetalation reactor is then passed on to the catalytic cracking
unit through line 55. The cut temperature of the vacuum still
depends on the specific crude oil and the efficiency of the
demetalation reactor, and is adjusted to yield an effluent from the
demetalation reactor having a metals factor no greater than about
5. When the demetalation reactor is efficient enough, the vacuum
tower can be completely circumvented and the bottoms from the
atmospheric still passed directly to the demetalation unit.
Both the conversion and gasoline yield from catalytic cracking can
often be improved by prior hydrogenation of the feed stock. Either
the percentage of crude suitable as feed stock to such a
conventional process or the life of the relatively expensive
hydrogenation catalyst can be increased by providing a prior
demetalation process using a relatively cheap disposable catalyst.
Thus, the demetalation reactor 64 of FIG. 4 could be replaced by a
complex consisting of both a demetalation reactor and a
hydrogenation reactor (not shown). For example, the system of
demetalation plus desulfurization and/or denitrogenation, described
in more detail in FIG. 3, could be used. The demetalation reactor
now permits an increase in the cut temperature of the vacuum still
or possibly direct use of the bottoms from the atmospheric still
with an increase in the amount of catalytic cracking feed stock.
The hydrogenation reactor, in turn, increases the hydrogen content
of the feed stock leading to greater gasoline production from a
given amount of feed stock. In the absence of the demetalation
reactor, either increasing the cut temperature or completely
bypassing the vacuum still would increase the amount of metals
reaching the hydrogenation catalyst and would significantly curtail
the life of this more expensive catalyst.
The following examples will be illustrative of the invention.
EXAMPLE 1
This example will illustrate the catalytic effect of manganese
nodules on demetalation of a topped crude charge stock. The charge
stock was Agha Jari topped crude and had the following physical
characteristics and chemical composition:
Initial Boiling Point (IBP) 400.degree.F. Gravity, .degree.API 24.4
Sulfur, weight percent (wt. %) 2.20 Nitrogen, wt. % 0.20 Conradson
Carbon Residue (CCR) wt. % 4.43 Nickel (Ni), parts per million
(ppm) 13.3 Vanadium (V), ppm 45.8
The manganese nodules were obtained from the bottom of Sturgeon Bay
in Lake Michigan. These nodules, after recovery from the lake
bottom, were washed to remove salt, water, and mud. They were then
crushed, leached with boiling water five times, dried to constant
weight at 100.degree. C., and sieved to 14-30 mesh (U.S. Standard
Sieve Series). The nodules had the following physical
characteristics and chemical composition:
Surface area, square meters per gram (m.sup.2 g.sup.-.sup.1) 200
Particle density, grams per cubic centimeter (g cm.sup.-.sup.3)
1.49 Pore diameter, Angstrom units (A) 81 Pore volume, cubic
centimeters per gram (cm.sup.3 g.sup.-.sup.1) 0.409 Real density, g
cm.sup.-.sup.3 3.75 Manganese (Mn), wt. % 9.19 Iron (Fe), wt. %
35.4 Nickel (Ni), wt. % <0.01 Cobaltous oxide (CoO), wt. % 0.04
Molybdenum trioxide (MoO.sub.3), wt. % 0.08
The nodules were placed in a downflow trickle-bed reactor, and
hydrogen and the topped crude were passed through the reactor for 7
days. The reaction conditions and results are shown in Table I.
The hydrogen consumption in Table I, and in the subsequent tables,
was a time-weighted average consumption over the course of the
run.
TABLE I
TIME ON STREAM, DAYS 0.08 0.52 1.04 1.54 2.04 2.54 3.04 3.45 6.96
HYDROGEN CONSUMPTION, Standard Cubic Feet of Hydrogen per Barrel of
Charge Stock (SCF/B) -- 73 FLUID PRODUCT PROPERTIES Gravity,
.degree.API 26.5 25.5 25.4 25.3 25.5 25.3 25.0 25.0 25.0 Sulfur, wt
% 1.22 1.52 1.61 1.66 1.70 1.71 1.73 1.70 1.87 Nitrogen, wt % 0.15
0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.20 CCR, wt % 2.81 3.86 3.95
3.96 4.32 3.88 4.05 4.19 4.31 Ni, ppm 0.8 2.6 3.0 3.7 4.4 4.8 4.7
5.5 5.5 V, ppm 0.5 2.8 3.2 4.8 6.1 6.3 6.1 8.1 12.9 %
DESULFURIZATION 44.5 30.9 26.8 24.5 22.7 22.3 21.4 22.7 15.0 % CCR
REDUCTION 36.6 12.9 10.8 10.6 2.5 12.4 8.6 5.4 2.7 % DEMETALATION
98.8 91.9 89.5 85.6 82.2 81.2 81.7 77.0 68.9
it will be observed from the table that the demetalation varied
from 98.8 to 68.9 percent over the course of the 7 -day run.
EXAMPLE 2
In this example, the effect of sulfiding the manganese nodules is
demonstrated. The charge stock and the nodules were the same as
those used in Example 1. However, after loading the nodules into
the reactor, the nodules were sulfided by passing through the
reactor 100 percent hydrogen sulfide at 320.degree. F., at 1
atmosphere pressure, and at a space velocity of 480 volumes of
hydrogen sulfide per volume of nodules for a period of 8 hours. The
topped crude oil and hydrogen were passed through the reactor for a
period of 10 days. Reaction conditions and results are given in
Table II.
It will be seen, comparing Tables I and II, that sulfiding of the
catalyst resulted in improvements in desulfurization, CCR
reduction, and demetalation although the improvements in
demetalation did not become marked until after two days on stream.
The beneficial effects were most pronounced on the CCR reduction
and least pronounced on the demetalation. It will also be seen that
the hydrogen consumption was 103 SCF/B whereas in Example 1 the
hydrogen consumption was 73 SCF/B. The higher consumption of
hydrogen in Example 2 is not considered to be of significance in
view of the fact that hydrogen consumption data is sensitive to
small errors in analysis. Any differences in hydrogen consumption
of less than 50 SCF/B can usually be attributed to analysis
error.
TABLE II
Temperature -- 750.degree. F. Pressure -- 2000 psig LHSV -- 1.27
H.sub.2 Circ -- 9,640-10,560 SCF/B TIME ON STREAM, DAYS 0.06 0.2
1.0 1.2 2.1 3.3 4.1 7.1 8.1 9.1 10.1 HYDROGEN CONSUMPTION,
SCF/B--103 LIQUID PRODUCT PROPERTIES Gravity, .degree.API 26.0 26.0
26.0 26.2 25.7 25.7 25.5 25.5 25.4 25.3 25.0 Sulfur, wt % 0.70 1.10
1.42 1.43 1.48 1.54 1.58 1.69 1.67 1.70 1.65 Nitrogen, wt % -- 0.14
0.18 0.18 0.18 0.19 0.19 0.19 0.19 0.19 0.09 CCR, wt % -- 2.61 3.40
3.57 3.15 3.34 3.73 -- 3.63 3.59 3.58 Ni, ppm 0.34 0.81 2.6 2.8 3.5
4.3 4.0 4.8 5.9 5.4 4.7 V, ppm 0.31 0.82 3.5 3.9 5.1 6.4 6.3 8.2
8.5 9.2 9.6 % DESULFURIZATION 68.2 50.0 35.5 35.0 32.7 30.0 28.2
23.2 24.1 22.7 25.0 % CCR REDUCTION -- 41.1 23.3 19.4 38.9 24.6
15.8 -- 18.1 19.0 19.2 % DEMETALATION 98.9 97.2 89.7 88.7 85.4 81.9
82.6 78.0 75.6 75.3 75.8
EXAMPLE 3
This example will illustrate the effect of temperature on the
demetalation activity of sulfided manganese nodules.
The procedure set forth above in Example 2 was continued for an
additional period of 6.9 days. However, during this additional
period, the temperatures employed were 800.degree. and 850.degree.
F. The reaction conditions and results are given in Table III. In
Table III, the hydrogen consumption is given only for the period
that the reaction was carried out at 800.degree. F. During the
period at which the reaction was carried out at 850.degree. F.,
difficulty was encountered in obtaining measurement of hydrogen
consumption.
It will be noted from Tables II and III that, at 750.degree. F.,
the demetalation at the beginning of operation was 98.9 percent.
However, demetalation decreased as the operation continued and at
the end of 10 days had declined to 75.8 percent. On the other hand,
with the temperature being increased at this time to 800.degree.
F., demetalation rose to 96.4 percent and remained at this figure
or higher for the entire 800.degree. F. portion of the operation.
At 850.degree. F., the demetalation was over 99 percent
complete.
TABLE III
Pressure -- 2000 psig LHSV -- 1.27 H.sub.2 Circ -- 9,830-10,560
SCF/B TIME ON STREAM, DAYS 11.1 14.4 14.9 15.4 16.6 15.9 16.9
TEMPERATURE, .degree.F. 800 800 800 800 850 800 850 HYDROGEN
CONSUMPTION, SCF/B -- 166 LIQUID PRODUCT PROPERTIES Gravity,
.degree.API 25.9 26.9 26.7 26.7 30.5 26.8 30.5 Sulfur, wt % 1.29
1.37 1.39 1.38 1.41 0.88 0.89 Nitrogen, wt % 0.18 0.18 0.18 0.18
0.18 0.15 0.17 CCR, wt % 2.87 3.05 3.14 3.20 3.11 1.15 1.18 Ni, ppm
1.1 1.2 1.4 1.3 1.3 0.2 0.2 V, ppm 1.0 0.7 0.7 0.7 0.6 0.1 0.3 %
DESULFURIZATION 41.4 37.7 36.8 37.3 35.9 60.0 59.5 % CCR REDUCTION
35.2 31.2 29.1 27.8 29.8 74.0 73.4 % DEMETALATION 96.4 96.8 96.4
96.6 96.8 99.5 99.2
EXAMPLE 4
This example will illustrate the catalytic effect of the manganese
nodules for demetalation of a whole crude oil. The crude oil was
Kuwait whole crude and had the following physical properties and
chemical composition:
Gravity, .degree.API 31.1 Sulfur, wt. % 2.79 Nitrogen, wt. % 0.13
CCR wt. % 5.20 Fe, ppm 0.57 Ni, ppm 9.4 V, ppm 29.0
The manganese nodules were the same as those employed in Example 1.
They were packed into a downflow trickle-bed reactor and sulfided
by passing 100 percent hydrogen sulfide through them at 450.degree.
F. and 1 atmosphere pressure for 8 hours at a space velocity of 480
volumes per volume of nodules per hour. After sulfiding, the crude
oil and hydrogen were passed through the reactor. The reaction
conditions and results are given in Table IV.
It will be seen that the demetalation activity of the catalyst was
high throughout the period of the reaction. Demetalation was 96.9
percent after 2 hours of operation. Even after 3 days of operation,
demetalation was still 82 percent.
TABLE IV
Temperature -- 750.degree. F. LHSV -- 1.33 Pressure -- 2000 psig
H.sub.2 Circ -- 6,910-9,870 SCF/B TIME ON STREAM, HOURS 2 13 23 27
37 49 61 72 HYDROGEN CONSUMPTION, SCF/B -- 52 LIQUID PRODUCT
PROPERTIES Gravity, .degree. API 30.8 30.8 30.8 30.7 30.6 30.4 30.4
30.1 Sulfur, wt % 1.00 1.82 2.01 1.99 2.04 2.10 2.16 2.18 Nitrogen,
wt % 0.06 0.11 0.12 0.12 0.13 0.13 0.13 0,13 CCR, wt % 2.10 3.80
3.83 3.26 4.22 4.16 0.36 4.42 4.50 ppm 0.49 0.61 <0.1 <0.1
<0.1 <0.1 <0.1 Ni, ppm 0.72 1.5 2.0 1.9 2.3 2.6 2.9 3.0 V,
ppm 0.13 1.3 2.3 2.4 2.5 3.3 3.9 4.0 % DESULFURIZATION 64.2 34.8
28.0 28.7 26.9 24.7 22.6 21.9 % CCR REDUCTION 59.6 26.9 26.3 37.3
18.8 20.0 15.0 13.4 % DEMETALATION 96.9 91.6 87.4 89.0 87.7 84.9
82.6 82.0
EXAMPLE 5
This example will illustrate the catalytic effect of manganese
nodules for demetalation of another topped crude oil. The nodules
were the same as those employed in Example 1 except that they were
sieved to 10-20 mesh. The nodules were packed into a downflow
trickle-bed reactor and sulfided as described in Example 1. The
charge stock was a Kuwait topped crude and had the following
characteristics:
IBP 400.degree. F. Gravity, .degree.API 20.3 Sulfur, wt. % 3.74
Nitrogen, wt. % 0.17 CCR, wt. % 7.1 Ni, ppm 9.2 V, ppm 32.8
Reaction conditions and results are given in Table V.
It will be seen from Table V that demetalation varied between 98.8
and 92.9 percent.
TABLE V
Temperature -- 800.degree. F. Pressure -- 2000 psig LHSV -- 1.00
H.sub.2 Circ -- 13,000 SCF/B TIME ON STREAM, DAYS 0.2 0.6 1.1 1.6
2.1 5.1 7.7 HYDROGEN CONSUMPTION SCF/B -- 283 LIQUID PRODUCT
PROPERTIES Gravity, .degree.API 30.1 27.5 26.5 26.5 26.0 25.6 25.4
Sulfur, wt % 0.83 1.46 1.69 1.81 1.98 2.22 Nitrogen, wt % 0.07 0.12
0.13 0.14 0.14 0.14 0.15 CCR, wt % 1.83 3.19 3.80 3.84 3.72 4.20
4.47 Ni, ppm 0.34 0.66 1.7 1.8 1.1 1.6 2.0 % DESULFURIZATION 77.8
61.0 54.8 51.6 -- th 47.1 40.6 % CCR REDUCTION 74.1 55.1 46.5 45.9
47.6 40.8 37.0 % DEMETALATION 98.9 97.7 94.7 94.5 96.2 94.4
92.9
EXAMPLE 6
This example will illustrate the catalytic effect of manganese
nodules on the demetalation of petroleum residual oil. The
petroleum residual oil was a Kuwait atmospheric residual oil and
had the following characteristics:
IBP 600.degree. F. Gravity, .degree.API 17 Sulfur, wt. % 3.52
Nitrogen, wt. % 0.19 CCR, wt. % 6-7% Ni, ppm 9.5 V, ppm 42.2
The nodules were the same as those employed in Example 1 except
that they were sieved to 10-20 mesh and were sulfided. Sulfiding
was effected by loading the nodules into an upflow reactor and
passing hydrogen sulfide through them. Sulfiding was carried out
under the same conditions as set forth in Example 2. Reaction
conditions and results are given in Table VI.
It will be noted that, over the approximately 19-day run, the
demetalation varied between 83.6 and 95.5 percent. ##SPC1##
EXAMPLE 7
This example will illustrate the results obtained employing a
conventional catalyst for demetalation of the same residual oil
employed in Example 6. The catalyst employed was a molybdenum
oxide-aluminum oxide catalyst and comprised 11.1 weight percent of
MoO.sub.3 on Al.sub.2 O.sub.3. It is identified by the trade name
"Harshaw Mo 1210 T". This catalyst was placed in a downflow reactor
and the residual oil and hydrogen were passed through it at a
variety of conditions. The conditions and results are given in
Table VII. The conditions used between 4.79 and 9.42 days in this
table were essentially the same as those employed in Example 6.
As shown in Table VII, the demetalation varied between 82.2 and
95.0 percent. This is comparable to the extent of demetalation
obtained with the manganese nodules in Example 6. However, the
hydrogen consumption in Example 7 was 563 SCF/B as compared to the
lower hydrogen consumption in Example 6 of 222 SCF/B. ##SPC2##
EXAMPLE 8
This example will illustrate the effect of the manganese nodules
from the Atlantic Ocean on the demetalation of a residual oil. The
example will also illustrate the effect of three other catalysts,
the first of which is not considered to have hydrogenation activity
and the other two of which contain metals or metal oxides which are
used to impart hydrogenation activity in conventional
hydroprocessing catalysts. The oil was a West Texas Sour vacuum
residual oil and had the following physical properties and chemical
composition:
Gravity, .degree.API 7.3 Hydrogen, wt. % 10.05 Sulfur, wt. % 4.02
Nitrogen, wt. % 0.36 CCR, wt. % 15.9 Ni, ppm 19 V, ppm 32
The manganese nodules were obtained from the Blake Plateau in the
Atlantic Ocean and, after crushing and washing with hot water, had
the following physical properties and chemical composition:
Surface Area, m.sup.2 g.sup..sup.-1 225 Particle Density, g
cm.sup..sup.-3 1.21 Pore Diameter, A 103 Pore Volume, (cm.sup.3
g.sup..sup.-1) 0.58 Real density, g cm.sup..sup.-3 4.06 Mn, wt. %
20.9 Fe, wt. % 13.3 Ni, wt. % 0.92 Co0, wt. % 0.43 Mo0.sub.3, wt. %
<0.1
These nodules were sieved to 14-30 mesh and were loaded into an
upflow reactor, and a West Texas Sour vacuum gas oil which was
relatively free of metallic constituents was passed over them along
with hydrogen for a period of 3 days at 2,000 psig at
700.degree.-750.degree. F. and a space velocity of 1.16 volumes of
gas oil per volume of nodules per hour. Thereafter, the West Texas
Sour vacuum residual oil was passed over the nodules along with the
hydrogen at a temperature of 750.degree. F. After a short time at
750.degree. F., the temperature was raised to 800.degree. F.
Results obtained at 800.degree. F. are given in Table VIII.
The three other catalysts were, respectively, (I) an alumina
(Al.sub.2 O.sub.3) containing 6 percent by weight of silica
(SiO.sub.2), (II) an alumina base containing 6 percent by weight of
silica and 0.5 percent by weight of nickel, and (III) an alumina
base containing 6 percent by weight of silica, 3.10 percent by
weight of cobalt oxide (CoO) and 17.3 percent by weight of
molybdenum oxide (MoO.sub.3). These catalysts were also loaded into
upflow reactors and the West Texas Sour vacuum residual oil along
with hydrogen was passed over the catalysts. Reaction conditions
and results obtained are also given in Table VIII.
TABLE VIII
CATALYST Nodules I II III TIME ON STREAM, DAYS 4.0* 3.6 6.9 5.6
TEMPERATURE, .degree.F. 803 804 801 800 PRESSURE, PSIG 2000 2000
2000 2000 LHSV 0.97 0.83 0.74 0.89 H.sub.2 CIRC 6620 8050 9560 7840
HYDROGEN CONSUMPTION, SCF/B 235 345 490 1060 LIQUID PRODUCT
PROPERTIES Gravity, .degree.API 11.2 11.8 12.8 17.7 Hydrogen, wt. %
10.38 10.37 10.36 11.45 Sulfur, wt. % 2.93 3.46 2.91 0.62 Nitrogen,
wt. % 0.38 0.37 0.36 0.29 CCR, wt. % 11.9 -- 14.0 8.1 Nickel, ppm
10 19 12 3 Vanadium, ppm 13.5 27 10 0.8 % DEMETALATION 53.9 9.8
56.9 92.5 *Total time on stream counting 3 days with vacuum gas
oil.
The table indicates that the extent of demetalation employing the
nodules was 53.9 percent. However, it was considered that this was
not a representative figure since, on opening the reactor, it was
discovered that about half of the catalyst charge had been removed
from the reactor by the oil and hydrogen passed through it. The
table also indicates that the extent of demetalation employing
Catalyst III was 92.5 percent. However, the table also indicates
that, while the nodules took out over one-half the metal removed by
Catalyst III, the hydrogen consumption with the nodules was less
than one-fourth that of Catalyst III. Further, the table shows that
the nodules are far superior to Catalyst I which contains no metal
or metal oxide component generally considered to have hydrogenation
activity and comparable to Catalyst II. The table also shows that
the hydrogen consumption with the nodules is significantly less
than Catalyst I and less than one-half that of Catalyst II.
EXAMPLE 9
This example will illustrate the demetalation of a topped petroleum
crude oil at relatively low pressures of hydrogen. A relatively
high space velocity also was employed.
The manganese nodules were the same as those employed in Example 2
and the topped petroleum crude oil was the same as that employed in
Example 1. The reaction conditions and the results obtained are
given in Table IX.
As shown in the table, the percent demetalation varied between 43.7
and 78.3 percent over the course of the run.
TABLE IX
Temperature -- 750.degree. F. Pressure -- 1015 psig LHSV -- 2.9
H.sub.2 Circ -- 10,000 SCF/B TIME ON STREAM, DAYS 0.10 0.23 0.64
1.14 1.64 2.14 2.37 HYDROGEN CONSUMPTION, SCF/B -- 81 LIQUID
PRODUCT PROPERTIES Gravity, .degree.API 26.1 25.2 24.9 24.9 24.9
24.9 24.9 Sulfur, wt % 1.42 1.67 1.74 1.79 1.82 1.81 1.80 Nitrogen,
wt % 0.17 0.19 0.19 0.19 0.20 0.10 0.20 0.20 CCR, wt % 3.46 4.06
3.85 4.05 3.93 4.17 4.26 Ni, ppm 4.1 6.4 6.3 9.35 9.1 10.4 10.2 V,
ppm 8.7 15.0 16.9 19.7 21.4 22.9 22.9 % DESULFURIZATION 35.5 24.1
20.9 18.6 17.3 17.7 18.2 % CCR REDUCTION 21.9 8.4 13.3 8.6 11.3 5.9
3.8 % DEMETALATION 78.3 63.8 60.7 50.8 48.4 43.7 44.0
EXAMPLE 10
This example will illustrate the demetalation of a topped petroleum
crude oil at a lower pressure and at a lower space velocity than in
the previous example.
The manganese nodules and the topped petroleum crude oil were the
same as those in the previous example. During the run, the
temperature was increased from 750.degree. F. to 800.degree. F. The
reaction conditions and the results obtained are shown in Table
X.
As shown, the percent demetalation varied between 93.1 and 59.2
percent over the course of the run.
TABLE X
Temperature -- 750.degree.--800.degree. F. Pressure -- 560 psig
LHSV -- 1.1 H.sub.2 Circ -- 10,000 SCF/B TIME ON STREAM, DAYS 0.11
0.25 0.64 1.14 1.64 2.14 2.63 3.09 HYDROGEN CONSUMPTION, SCF/B --
85 TEMPERATURE, .degree.F. 750 750 750 750 750 800 800 800 LIQUID
PRODUCT PROPERTIES Gravity, .degree.API 27.5 -- 25.5 25.6 25.3 25.4
26.4 -- Sulfur, wt % 1.04 -- 1.51 1.63 1.65 1.45 1.53 1.54
Nitrogen, wt % .15 -- 0.19 0.19 0.19 0.18 0.19 0.19 CCR, wt % 2.38
3.12 3.90 4.17 4.27 3.33 3.63 3.54 Ni, ppm 1.4 2.8 5.5 7.1 7.6 4.6
5.6 5.7 V, ppm 2.7 6.0 11.8 16.9 16.5 7.9 8.6 7.8 % DESULFURIZATION
52.7 -- 31.4 25.9 25.0 34.1 30.5 30.0 % CCR REDUCTION 46.3 29.6
12.0 5.9 3.6 24.8 18.1 20.0 % DEMETALATION 93.1 85.1 70.7 59.4 59.2
78.8 76.0 77.2
EXAMPLE 11
This example will illustrate the demetalation activity of manganese
nodules obtained from the Atlantic Ocean on a topped petroleum
crude oil.
The nodules employed were obtained from the Blake Plateau in the
Atlantic Ocean. These nodules, after crushing and washing with hot
water, had the following physical properties and chemical
composition:
Surface Area, m.sup.2 g.sup..sup.-1 226 Particle Density, g
cm.sup..sup.-3 1.43 Pore Diameter, A 73 Pore Volume, cm.sup.3
g.sup..sup.-1 0.41 Real Density, g cm.sup..sup.-3 3.53 Mn, wt. %
18.8 Fe, wt. % 12.3 Ni, wt. % 0.72 CoO, wt. % 0.46 Mo0.sub.3, wt. %
0.1
The topped petroleum crude oil was the same as that employed in
Example 1. The reaction conditions and results obtained are given
in Table XI.
As shown, the demetalation varied between 95.8 and 79.7 percent
over the course of the run.
TABLE XI
Temperature -- 750.degree. F. Pressure -- 2000 psig LHSV -- 1.3
H.sub.2 Circ -- 10,000 SCF/B TIME ON STREAM, DAYS .10 0.45 0.90
1.36 HYDROGEN CONSUMPTION, SCF/B -- 174 LIQUID PRODUCT PROPERTIES
Gravity, .degree.API 25.5 24.7 -- 25.3 Sulfur, wt % 1.40 1.63 1.71
1.69 Nitrogen, wt % 0.17 0.19 0.20 0.20 CCR, wt % 3.19 3.85 3.89
3.89 Ni, ppm 1.2 2.7 4.9 5.9 V, ppm 1.3 5.0 7.1 5.9 %
DESULFURIZATION 36.4 25.9 22.3 23.2 % CCR REDUCTION 28.0 13.1 12.2
12.1 % DEMETALATION 95.8 87.0 79.7 83.6
EXAMPLE 12
This example will illustrate the demetalation effect of manganese
nodules from the Pacific Ocean on a topped petroleum crude oil.
The nodules employed were obtained from the Pacific Ocean and,
after crushing and washing with hot water, had the following
physical properties and chemical composition:
Surface Area, m.sup.2 g.sup..sup.-1 230 Particle Density, g
cm.sup..sup.-1 1.52 Pore Diameter, A 69 Pore Volume, cm.sup.3
g.sup..sup.-1 0.40 Real Density, g cm.sup..sup.-3 3.80 Mn, wt. %
28.5 Fe, wt. % 13.9 Ni, wt. % 1.21 CoO, wt. % 0.23 Mo0.sub.3, wt. %
0.1
The nodules were sieved to 14-30 mesh and sulfided in accordance
with the procedure described in Example 2. The reaction conditions
and results obtained are given in Table XII.
As shown, the demetalation varied between 60.1 and 86.1 percent
over the course of the run.
TABLE XII
Temperature -- 750.degree. F. Pressure -- 2000 psig LHSV -- 1.2
H.sub.2 Circ -- 10,000 SCF/B TIME ON STREAM, DAYS 0.06 0.20 0.60
1.10 1.60 2.15 2.60 HYDROGEN CONSUMPTION, SCF/B -- 69 LIQUID
PRODUCT PROPERTIES Gravity, .degree.API 26.5 25.5 25.1 25.0 25.0
25.0 25.0 Sulfur, wt % 1.20 1.39 1.49 1.50 1.52 1.47 1.53 Nitrogen,
wt % .17 .19 .20 .20 .20 .20 .20 CCR, wt % 3.17 3.58 4.04 4.29 4.23
4.11 4.15 Ni, ppm 4.1 3.2 5.1 8.9 6.9 6.9 7.8 V, ppm 11.4 5.0 8.2
14.7 13.4 9.3 14.3 % DESULFURIZATION 45.5 36.8 32.3 31.8 30.9 33.2
30.5 % CRR REDUCTION 28.4 19.2 8.8 3.2 4.5 7.2 6.3 % DEMETALATION
73.8 86.1 77.5 60.1 65.7 72.6 62.6
EXAMPLE 13
This example will demonstrate the sensitivity of manganese nodules
to the effect of sulfur with respect to the hydrogenation of
aromatic compounds.
In this example, in the first portion thereof, benzene and hydrogen
were passed over three different catalysts packed into a reactor.
The first two catalysts were Atlantic Ocean nodules having the
physical characteristics and chemical composition as given in
Example 8, and Lake Michigan nodules having the physical properties
and chemical composition given in Example 1. The third catalyst was
the same type of conventional catalyst containing CoO/MoO.sub.3
employed in Example 7. The reaction conditions were as follows:
Temperature 700.degree. F. Pressure 1,050 psig LHSV 4.0 Ratio of
Hydrogen to Benzene 2.68
At the end of two hours, the effluent stream from the reactors was
analyzed for the proportion of cyclohexane contained therein. The
results are given in Table XIII.
TABLE XIII
Catalyst Mole Percent of Cyclohexane Atlantic Ocean Nodules 87.6
Lake Michigan Nodules 45.3 Co0/Mo0.sub.3 93.1
It will be observed from Table XIII that each of the catalysts had
significant benzene hydrogenation activity, with the CoO/MoO.sub.3
having the greatest activity.
In the second portion of this example, the procedure was repeated
except that an olefin, i.e., hexene-1, and a sulfur-containing
organic compound, i.e., 2-methyl thiophene, were mixed with the
benzene. The mixture had the following composition in weight
percent:
Benzene 79.4 Hexene-1 18.2 2-Methyl Thiophene 2.4
The reaction conditions were:
Temperature 700.degree. F. Pressure 1050 psig LHSV 4.0 Ratio of
Hydrogen to other reactants 10.0
After 22.5 hours on stream, the effluent streams from the reactors
were analyzed to determine the extent of benzene and hexene-1
hydrogenation and sulfur removal. The results are given in Table
XIV.
TABLE XIV
Benzene Hexene-1 Sulfur Hydro- Hydro- Removal genated genated
Weight Catalyst Mole Mole Percent Percent Percent Atlantic Ocean
<0.1 72 41 Nodules Lake Michigan <0.1 100 90 Nodules
Co0/Mo0.sub.3 3.3 100 91
The runs were continued for an additional 5 hours but the
temperature was increased to 800.degree. F. Analyses were again
made of the effluent stream from the reactors and the results are
given in Table XV.
TABLE XV
Benzene Hexene-1 Sulfur Hydro- Hydro- Removal genated genated
Weight Catalyst Mole Mole Percent Percent Percent Atlantic Ocean
<0.1 93 92 Nodules Lake Michigan <0.1 100 93 Nodules
CoO/MoO.sub.3 6.2 100 93
as will be seen from Tables XIV and XV, the manganese nodules, in
the presence of the sulfur-containing compound, had essentially no
activity for hydrogenating the benzene but had activity for
hydrogenating the olefin. On the other hand, the CoO/MoO.sub.3
catalyst retained some of its activity for hydrogenating the
benzene in the presence of the sulfur-containing compound.
EXAMPLE 14
This example will illustrate the processing sequence, described in
connection with FIG. 3, of demetalation followed by hydroprocessing
for sulfur and nitrogen removal. The Kuwait atmospheric residual
oil described in Example 6 is fed to the demetalation reactor 14.
The catalyst in the demetalation reactor is manganese nodules which
have been crushed to small particle size. The ebullating bed
demetalation reactor is operated at 800.degree. F., a LHSV of 1.0,
a pressure of 2,000 psig, and a hydrogen circulation rate of 10,000
SCF/B. Ten percent of the catalyst in the demetalation reactor is
withdrawn daily and an equivalent amount of fresh catalyst added
daily.
The metals content of the liquid product from the demetalation
reactor is significantly reduced relative to that of the feed to
the demetalation reactor. The sulfur content is also reduced but to
a lesser extent. The product from the demetalation reactor is
passed on to the desulfurization reactor 36. The catalyst in the
desulfurization reactor is cobalt molybdate on alumina. The
desulfurization reactor is operated at a LHSV of 1.0, a temperature
of 800.degree. F., a pressure of 2,000 psig and a hydrogen
circulation rate of 10,000 SCF/B. The sulfur content of the product
from the desulfurization reactor is significantly reduced relative
to the feed to the desulfurization reactor.
EXAMPLE 15
This example will illustrate the processing sequence, described
above in connection with FIG. 4, of demetalation prior to catalytic
cracking. A Kuwait crude oil is fed to atmospheric still 50. The
bottoms from the atmospheric still, which are very similar to the
Kuwait atmospheric residual oil described in Example 6, are passed
to vacuum still 62. The cut temperature of the vacuum still is
adjusted so that the overhead has a metals factor of about 50. This
overhead is then passed on to demetalation reactor 64. The catalyst
in the demetalation reactor is manganese nodules which have been
crushed to small particle size. The ebullating bed demetalation
reactor is operated at a LHSV of 0.5, a pressure of 2,000 psig, and
a hydrogen circulation rate of 10,000 SCF/B. Ten percent of the
catalyst in the demetalation reactor is withdrawn daily and an
equivalent amount of fresh catalyst added daily. The temperature of
the demetalation reactor is controlled such that the product from
this reactor has a metals factor of about 5. This product is then
passed on to catalytic cracking unit 60.
EXAMPLE 16
This example will illustrate a processing sequence of demetalation
and hydrogenation prior to catalytic cracking. A Kuwait crude oil
is fed to atmospheric still 50 as illustrated in FIG. 4. The
bottoms from the atmospheric still, which are very similar to the
Kuwait atmospheric residual oil described in Example 6, are passed
to vacuum still 62. The cut temperature of the vacuum still is
adjusted so that the overhead has a metals factor of about 50. This
overhead is then passed on to demetalation reactor 64 containing
manganese nodules which have been crushed to small particle size.
The ebullating bed demetalation reactor is operated at a
temperature of 800.degree. F., a LHSV of 1.0, a pressure of 2,000
psig, and a hydrogen circulation rate of 10,000 SCF/B. Ten percent
of the catalyst in the demetalation reactor is withdrawn daily and
an equivalent of fresh catalyst added daily.
The product from the demetalation reactor, which has been
significantly reduced in metals content relative to the feed to the
demetalation reactor, is passed on to a hydrogenation reactor,
i.e., the desulfurization reactor 36 illustrated in FIG. 3. The
catalyst in the hydrogenation reactor is cobalt molybdate on
alumina. The hydrogenation reactor is operated at a LHSV of 1.0, a
temperature of 700.degree. F., a pressure of 2,000 psig, and a
hydrogen circulation rate of 7,500 SCF/B. The hydrogen content of
the liquid effluent from the hydrogenation reactor is significantly
increased relative to the feed to the hydrogenation reactor. This
effluent is then passed on to the catalytic cracking unit 60.
The gasoline yield and conversion from this processing sequence are
now far in excess of that obtainable by catalytic cracking alone;
and a steady-state cracking operation is achieved with a charge
stock metals input far in excess of that achieved by catalytic
cracking.
* * * * *