U.S. patent number 3,870,623 [Application Number 05/397,071] was granted by the patent office on 1975-03-11 for hydroconversion process of residuum oils.
This patent grant is currently assigned to Hydrocarbon Research, Inc.. Invention is credited to Seymour B. Alpert, Axel R. Johnson, Ronald H. Wolk.
United States Patent |
3,870,623 |
Johnson , et al. |
March 11, 1975 |
HYDROCONVERSION PROCESS OF RESIDUUM OILS
Abstract
In processing high metals Venezuelan residuum, higher conversion
of the 975.degree.F plus fraction and improved operability can be
obtained by maintaining a high catalyst addition rate to obtain
reduced metals loading on the catalyst; it being determined that
for a macroporous catalyst there is a limiting factor of metals
deposition.
Inventors: |
Johnson; Axel R. (North
Babylon, NJ), Wolk; Ronald H. (Trenton, NJ), Alpert;
Seymour B. (Los Altos, CA) |
Assignee: |
Hydrocarbon Research, Inc. (New
York, NY)
|
Family
ID: |
26905153 |
Appl.
No.: |
05/397,071 |
Filed: |
September 13, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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210436 |
Dec 21, 1971 |
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Current U.S.
Class: |
208/108; 208/48R;
208/157; 208/112; 208/251H |
Current CPC
Class: |
C10G
45/16 (20130101) |
Current International
Class: |
C10G
45/02 (20060101); C10G 45/16 (20060101); C10g
013/02 (); C10g 009/16 (); B01j 011/74 () |
Field of
Search: |
;208/108,112,164,251H |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gantz; Delbert E.
Assistant Examiner: Schmitkons; G. E.
Parent Case Text
RELATED APPLICATION
This is a continuation of application Ser. No. 210,436, filed Dec.
21, 1971, and now abandoned.
Claims
We claim:
1. In a process for the continuous hydrogenation of a Lagunillas
vacuum bottoms having in excess of 500 ppm of metals from the group
of vanadium and nickel wherein the residuum and hydrogen are passed
upwardly through a reaction zone containing a macroporous
microspherical particulate catalyst being closely sized within the
range of 60 to 325 U.S. Standard mesh at a rate to place the
microspherical catalyst in random motion in the liquid without
substantial carryover from the reaction zone and wherein the
operating conditions are within a pressure range of 1,000 to 3,000
PSIG, and a temperature range of 750.degree. to 850.degree.F and a
liquid space velocity of 0.2 to 2.0 V.sub.f /hr/V.sub.r such as to
maintain conversion of at least 80 percent of the portion of the
residuum boiling above 975.degree.F to material boiling below
975.degree.F wherein the improvement comprises:
adding said catalyst to and removing said catalyst from the
reaction zone at a rate between 0.2 and 0.5 pounds of catalyst per
barrel of feed oil such that the percent of vanadium on the spent
catalyst is less than 23 percent.
2. The process of claim 1 wherein the catalyst addition and
withdrawal rate is between 0.4 and 0.5 pounds of catalyst per
barrel of feed oil.
Description
BACKGROUND OF THE INVENTION
The ebullated bed system described by Johanson in U.S. Reissue Pat.
No. 25,770 has proved successful in hydrogenation, including
hydrocracking and hydrodesulfurization, of a wide variety of
petroleum stocks. The advantages of high throughput, uniform
temperature, low pressure drop and non-plugging characteristics
have been of great benefit to residuum processors. Liquid phase
conditions assure good catalyst contact with no substantial
attrition.
In processing vacuum residuum, such as Lagunillas, which contain in
excess of 500 ppm of vanadium, conversion was limited to about 50
percent of the feed boiling above 975.degree.F to lower boiling
products in a non-replacement catalyst system. The high metals
levels and high asphaltene content of Venezuelan residuum makes
them difficult to convert due to the rapid poisoning of catalyst.
This results in a short onstream time and, therefore, low
conversion rates are obtained. As the amount of metals deposition
on the catalyst increases the residuum begins to coke in the
reactor. The coking then causes the rapid defluidization of the
catalyst bed and this requires that the reactor be then shut down.
However, a catalyst replacement reactor system utilizing a catalyst
replacement rate such that not more than about 23 percent of
vanadium was deposited on the catalyst showed long term successful
operations even in the 70-80 percent conversion range.
SUMMARY OF THE INVENTION
A system for obtaining in excess of a 70 percent conversion of the
975.degree.F plus fraction in high metals residuums is disclosed
using an ebullated bed reactor system. This system operates by
replacing the demetalization catalyst at a rate sufficient to limit
vanadium deposition, thereby assuring continuous operability. The
process for this invention is carried out at temperatures from
750.degree. to 850.degree.F, pressures of 1,000 to 3,000 psig,
space velocity of 0.2 to 2.0 V.sub.f /hr/V.sub.r (volume of feed
per hour per volume of reactor) and a hydrogen circulation of 4,000
to 10,000 SCF of hydrogen per barrel of liquid product.
DESCRIPTION OF THE DRAWING
The drawing is a schematic drawing of the preferred embodiment of
the process for the hydroconversion of high metals content residua
using a continuous demetalization catalyst replacement.
PREFERRED FORM OF EMBODIMENT
In the drawing, a high metals containing residuum feed 10 is
preferably combined with a catalyst 12 and fed by line 14 with
hydrogen from line 16 in upflow through a reactor generally
designated 18. Residua containing high metals are exemplified by
Lagunillas vacuum bottoms, Venezuelan atmospheric bottoms, Tia
Juana vacuum bottoms and the like with metals levels of at least
100 ppm and preferably 500 ppm. The metals are basically vanadium
and nickel. The reactor may have a liquid distributor and catalyst
support 20 so that the liquid and gas passing upwardly through the
reactor 18 will tend to place the catalyst in random motion in the
liquid.
The catalyst particle size range is usually of a narrow size range
for uniform expansion and random motion of the catalyst bed under
controlled liquid and gas flow conditions. While the overall range
of sizes that can be used is usually between 3 and 325 mesh (USS),
a once through operation uses catalyst in the 60 to 325 mesh range
with a liquid velocity in the order of 1 to 10 gallons per minute
per square foot of horizontal reaction space. Alternatively, larger
catalyst, usually in the 3 to 60 mesh size, can be used by adequate
recycle of oil to provide from about 10 to 60 gallons total liquid
velocity per minutes per square foot of horizontal reactor space.
The lifting effect of the hydrogen and oil are factors in the
buoyancy of the catalyst.
High metals containing residua are considered heavy hydrocarbon
oils. Such oils are most preferably hydrogenated with the use of
catalytic macroporous microspheres. These macroporous microspheres
are composed of platinum, palladium, molybdenum, nickel or cobalt
and the oxides or sulfides thereof or mixtures thereof supported on
an alumina or silica carrier or mixtures thereof as a carrier.
A macroporous microsphere catalyst according to this invention
should be of a type and fall within a given size range as
hereinbefore described. At the same time the macroporous
microspheres have a pore volume of from about 0.10 cc/g to 0.60
cc/g comprising pores larger than 250A and a pore volume of from
about 0.30 cc/g to 0.50 cc/g comprising pores with a diameter of
less than 250A. The total pore volume of the macroporous
microspheres is between about 0.40 cc/g and about 1.10 cc/g. A
preferred macroporous microsphere catalyst would have a pore volume
of from about 0.2 to about 0.4 cc/g in pores with a diameter larger
than 250A and a pore volume from about 0.35 to about 0.45 cc/g in
pores with a diameter of less than 250A and the total pore volume
is between about 0.55 and about 0.85 cc/g.
The macroporous microspheres have an average size such that 80
weight percent fall within a narrow size range and are ebullated by
the upward flow of oil and hydrogen through the reactor during
hydroconversion. The pore volume of the microspheres is critical as
there must be a penetration of the hydrocarbon oil into the
catalyst for at least a 3 percent gain in weight. These
microspheres are more specifically disclosed in U.S. Pat. No.
3,622,500.
By the control of the microspherical catalyst particle size and
density and the liquid and gas velocities and taking into account
the viscosity of the liquid under the operating conditions, the
catalyst bed may be expanded to have a definite solids level or
interface indicated at 22 in the liquid. The settled or static
level of the catalyst is considerably lower than level 22.
Normally, bed expansion should be at least 10 percent and seldom
over 300 percent of the static level.
The entire effluent is removed overhead at 24 and passed with such
hydrogen as may be required from line 32 into the second stage
reactor 34. This reactor is similar to the first stage reactor
except that a vapor separating space 36 is provided at the top. The
vapors, substantially solids-free and liquid-free are removed at 38
and a liquid is removed over trap tray 40 through line 42. The
upper solids level is indicated at 44 and the upper liquid level is
indicated at 46.
While we have shown microspherical catalyst addition through line
12, it is also convenient to add catalyst directly to the upper
part of the reactors as through lines 54 and remove it through
lines 56 using suitable valves as more particularly disclosed in
the Ehrlich, et al., U.S. Pat. No. 3,547,809. The catalyst is added
and removed at a high rate in the range of 0.2 to 0.5 lbs. of
catalyst per barrel of feed oil so as to maintain the percent
vanadium on the spent microspherical catalyst at less than 23
percent. Under these conditions the reactor operates without
defluidization or coking.
In a reactor system of this type, the vapor overhead 38 is largerly
hydrogen which may be purified by conventional means and after
being appropriately reheated and recompressed, can be recyled to
the hydrogen feed line 16 and 32 to the reactors.
Although it is preferable to hydrogenate the feeds in a two stage
system, a single stage is also suitable.
Table I shows the results of five operations for the hydrogenation
of heavy metals containing residuum using macroporous microspheres
as the catalyst. From the results it can be seen that the
microspherical catalyst must be added and removed at a rate such
that the spent catalyst has less than 23 percent vanadium deposited
on it. In this manner at least 70 percent conversion of the feed is
maintained without the defluidization and coking of the
microspherical catalyst bed taking place.
TABLE I
__________________________________________________________________________
I II III IV V
__________________________________________________________________________
FEED A* A A B* C* .degree.API 4.0 4.0 4.0 18 8 % S 2.75 2.75 2.75
2.2 2.7 ppm V 535 535 535 200 570 Vol. % 975.degree.F+ 75 75 75 50
89 OPERATING CONDITIONS Temperature .degree.F 830 840 830 825 820
Pressure psig Circulation 2250 2250 2250 2000 2000 H.sub.2 SCF/Bbl
5000 9000 5000 6000 6000 Space Velocity V.sub.f /hr/V.sub.r 0.6 0.5
0.6 0.5 0.4 CONVERSION** 72% 81% 73% 75% 70% Cat. Rate No./bbl.
0.36 0.36 0.18 0.18 0.18 % Vanadium on Spent Catalyst 20 21 40 8 23
Reactor Operability Satisfac- Satisfac- Coked Satisfac- Coked tory
tory tory
__________________________________________________________________________
*A is Lagunillas Vacuum Bottoms combined with 20% decant oil. B is
a light Venezuelan Atmospheric Bottoms. C is Tia Juana Vacuum
Bottoms. **Conversion is disappearance of 975.degree.F plus
material.
Above 70 percent conversion, 85 percent of vanadium in the feed is
removed, 94 percent of which ends up on catalyst. Therefore, 80
percent of vanadium ends up on catalyst.
While we have shown and described the preferred form of embodiment
of our invention, it will be apparent that modifications may be
made thereto without departing from the scope and spirit of the
description herein and of the claims appended hereinafter.
* * * * *