U.S. patent application number 10/990084 was filed with the patent office on 2005-06-02 for hydrocracking catalyst and method of hydrocracking heavy oil.
Invention is credited to Fukuyama, Hidetsugu, Terai, Satoshi, Uchida, Masayuki.
Application Number | 20050115870 10/990084 |
Document ID | / |
Family ID | 34463859 |
Filed Date | 2005-06-02 |
United States Patent
Application |
20050115870 |
Kind Code |
A1 |
Fukuyama, Hidetsugu ; et
al. |
June 2, 2005 |
Hydrocracking catalyst and method of hydrocracking heavy oil
Abstract
In a process of hydrocracking heavy oil with a catalyst in
petroleum refining, asphaltene contained in heavy oil, and
impurities including heavy metals such as nickel and vanadium, are
efficiently removed with activated carbon, whereby the reduction in
catalyst activity or formation of coke by the impurities can be
prevented. The invention provides a hydrocracking catalyst
comprising activated carbon extrudate as a carrier activated with
steam and having a high distribution of pores having pore sizes in
the range of 20 to 200 nm.
Inventors: |
Fukuyama, Hidetsugu; (Chiba,
JP) ; Terai, Satoshi; (Chiba, JP) ; Uchida,
Masayuki; (Chiba, JP) |
Correspondence
Address: |
FLYNN THIEL BOUTELL & TANIS, P.C.
2026 RAMBLING ROAD
KALAMAZOO
MI
49008-1699
US
|
Family ID: |
34463859 |
Appl. No.: |
10/990084 |
Filed: |
November 16, 2004 |
Current U.S.
Class: |
208/111.3 ;
208/111.35; 502/185; 502/321; 502/325; 502/337; 502/338 |
Current CPC
Class: |
B01J 23/88 20130101;
B01J 23/883 20130101; C10G 47/12 20130101; B01J 35/10 20130101;
B01J 35/1066 20130101; C10G 2300/4018 20130101; C10G 2300/301
20130101; C10G 2300/807 20130101; C01B 32/336 20170801; B01J 23/75
20130101; B01J 23/745 20130101; C10G 2300/206 20130101; B01J 21/18
20130101; B01J 35/108 20130101; B01J 23/755 20130101; B01J 35/1061
20130101; B01J 35/1042 20130101; B01J 35/1047 20130101; C10G
2300/703 20130101; B01J 37/10 20130101; B01J 23/74 20130101; C10G
2300/205 20130101; B01J 23/28 20130101; B01J 37/0009 20130101 |
Class at
Publication: |
208/111.3 ;
208/111.35; 502/337; 502/338; 502/325; 502/321; 502/185 |
International
Class: |
C10G 047/02; B01J
021/18 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 28, 2003 |
JP |
2003-398454 |
Claims
1. A method of hydrocracking heavy oil, comprising the step of
hydrocracking heavy oil in a fixed bed, a moving bed or an
ebullating bed with a hydrocracking catalyst comprising activated
carbon extrudate as a carrier activated with steam and having a
high distribution of pores having pore diameter in the range of 20
to 200 nm and any one of the group VIIIB metals selected from iron,
nickel and cobalt or molybdenum, both nickel and molybdenum, or
both cobalt and molybdenum, under the conditions of a pressure of 8
to 20 MPa, a temperature of 380 to 450.degree. C., an LHSV of 0.1
to 1.0 hr.sup.-1, and an H.sub.2/oil ratio of 350 to 1500
Nm.sup.3/kl-oil.
2. The method according to claim 1, wherein the heavy oil is a
hydrocarbon oil containing 70 vol % fraction or more with the
boiling point at 525.degree. C. or more, a hydrocarbon oil
containing at least 200 to 2000 wppm nickel and/or vanadium as
heavy metal, or a hydrocarbon oil containing 8 to 30 wt %
asphaltene (heptane insolubles).
3. The method according to claim 1, wherein, in the activated
carbon extrudate, the volume of pores determined by mercury
porosimetry is 0.7 to 1.8 ml/g, the proportion of pores having pore
diameter in the range of 20 to 200 nm is 20 vol % or more, and the
ratio by volume of pores having pore diameter in the range of 38 to
90 nm to pores having pore diameter in the range of 20 to 200 nm is
40% or more.
4. The method according to claim 1, wherein, in the activated
carbon extrudate, the volume of pores determined by mercury
porosimetry is 0.7 to 1.8 ml/g, the proportion of pores having pore
diameter in the range of 20 to 200 nm is 20 vol % or more, the
ratio by volume of pores having pore diameter in the range of 38 to
90 nm to pores having pore diameter in the range of 20 to 200 nm is
40% or more, and the ability of the activated carbon to adsorb
asphaltene is 22%/ml or more.
5. The method according to claim 1, wherein the catalyst comprises
iron, cobalt or nickel as the catalyst component.
6. A hydrocracking catalyst comprising activated carbon extrudate
as a carrier activated with steam and having a high distribution of
pores having pore diameter in the range of 20 to 200 nm and any one
of the group VIIIB metals selected from iron, nickel and cobalt or
molybdenum, both nickel and molybdenum, or both cobalt and
molybdenum.
7. The catalyst according to claim 6, wherein, in the activated
carbon extrudate, the volume of pores determined by mercury
porosimetry is 0.7 to 1.8 ml/g, the proportion of pores having pore
diameter in the range of 20 to 200 nm is 20 vol % or more, and the
ratio by volume of pores having pore diameter in the range of 38 to
90 nm to pores having pore diameter in the range of 20 to 200 nm is
40% or more.
8. The catalyst according to claim 6, wherein, in the activated
carbon extrudate, the volume of pores determined by mercury
porosimetry is 0.7 to 1.8 ml/g, the proportion of pores having pore
diameter in the range of 20 to 200 nm is 20 vol % or more, the
ratio by volume of pores having pore diameter in the range of 38 to
90 nm to pores having pore diameter in the range of 20 to 200 nm is
40% or more, and the ability of the activated carbon to adsorb
asphaltene is 22%/ml or more.
9. A hydrocracking catalyst, comprising activated carbon extrudate
as a carrier, activated with steam, and having a pore size
distribution with a high proportion of pores having pore diameter
in the range of 20 to 200 nm, the pore size distribution
particularly having a peak; and any one of the group VIII metals
selected from iron, nickel, and cobalt, or molybdenum; both nickel
and molybdenum; or both cobalt and molybdenum.
10. The catalyst according to claim 9, wherein the volume
proportion of pores in the range of 20 to 200 nm is 20% or more;
the volume ration of pores having a pore diameter in the range of
38 to 90 nm to pores having a pore diameter in the range of 20 to
200 nm is more than 40%; and/or the differential pore size
distribution has a peak, said peak being in the pore size range 20
to 200 nm, or/and said peak having a height of at least 0.4
cm.sup.3/g.
11. A process of manufacturing a hydrocracking catalyst, comprising
the steps of providing a starting carbon source, grinding said
starting carbon source into fine particles; preparing an extrudable
mixture from said fine particles; molding the material by
extruding; activating the extrudate with an activating gas; and
converting the activated carbon extrudate into the catalyst by
adding a catalyzing metal or metal compound; characterized in that
said activating gas comprises steam and optionally air, such that
the oxygen content is not more than 4 vol %.
12. The process according to claim 11, in which the starting carbon
source is selected from the group consisting of charcoal, coconut
shell carbon, peat, lignite, brown coal, bituminous coal and
petroleum cokes; the material is extruded at a pressure of 300 to
600 Mpa; and the extrudate is activated with an activating gas for
4 to 12 hours.
13. The process according to claim 11, which further comprises
providing an activated carbon extrudate and again activating said
activated carbon extrudate with steam.
14. The catalyst, obtainable by the process according to claim
11.
15. Use of the catalyst according to claim 6 for hydrocracking a
heavy oil.
16. The method according to claim 1, wherein the catalyst is
obtainable by a process comprising the steps of providing a
starting carbon source, grinding said starting carbon source into
fine particles; preparing an extrudable mixture from said fine
particles; molding the material by extruding; activating the
extrudate with an activating gas; and converting the activated
carbon extrudate into the catalyst by adding a catalyzing metal or
metal compound; characterized in that said activating gas comprises
steam and optionally air, such that the oxygen content is not more
than 4 vol %.
Description
TECHNICAL FIELD
[0001] The present invention relates to a hydrocracking catalyst
and to a method of hydrocracking heavy oil by using it. More
specifically, it relates to a method wherein in a step of
hydrocracking heavy oil with a catalyst in petroleum refining,
asphaltene and impurities including metals such as nickel and
vanadium contained in heavy oil are removed with activated carbon
so that the reduction in catalyst activity or formation of coke by
the impurities is prevented.
PRIOR ARTS
[0002] A method of treating heavy oil with a catalyst includes
fluid catalytic cracking (FCC), hydrocracking, etc. In fluid
catalytic cracking, raw oil is fluidized together with a silica
alumina catalyst or a zeolite catalyst, and pyrolyzed to produce
gasoline mainly. The catalyst on which coke formed and accumulated
in the cracking reaction is recycled and reused after the coke is
burned in a regenerating tower.
[0003] In hydrocracking, heavy oil is hydrocracked with an alumina
supported catalyst in high-pressure hydrogen thereby producing
naphtha, kerosene and gas oil, while impurities such as sulfur,
nitrogen, nickel and vanadium are removed. The coke formed in the
reaction, and nickel and vanadium released from asphaltene by
cracking, are accumulated on the catalyst, and thus the catalyst is
exchanged or replenished with a new catalyst. In hydrocracking, a
guard reactor is arranged in a previous stage such that the nickel
and vanadium are captured with an alumina catalyst having pores of
relatively large pore size to remove the metal.
[0004] Generally, the pore size means "diameter" so that when the
present specification refers to pore size, "diameter" is referred
to. In a graph or in analysis of pore size, however, "radius" is
generally used in discussion, and thus "radius" is referred to in a
graph in the present specification.
[0005] In the process using these catalysts, the catalysts are
deactivated by asphaltene, nickel, vanadium etc. contained in a raw
oil, and thus the amount of the catalysts used is increased.
[0006] To solve this problem in the process using these catalysts,
a method of removing asphaltene and impurities such as nickel and
vanadium in a raw oil by pre-treating the raw oil includes a
process of removing impurities with a solvent, which involves
merely extracting light fraction free of impurities from heavy
distillates containing a large amount of impurities with a solvent
to separate them from each other. These prior art techniques are
described briefly by Speight, J. G. in The Desulfurization of Heavy
Oils and Residua, Marcel Dekker (1981).
[0007] Mobile (U.S. Pat. No. 5,364,524 and U.S. Pat. No. 5,358,634)
discloses a method of using activated carbon as a catalyst used in
hydrocracking and a method of hydrocracking with metal together
with activated carbon.
[0008] In the activated carbon catalyst prescribed in these US
publications, the volume of pores having a diameter size of 100 to
400 .ANG. (10 to 40 nm) is at least 0.08 cc/g, desirably 0.2 cc/g,
and the average pore diameter is about 15 to about 100 .ANG. (1.5
to 10 nm), desirably 40 to 90 .ANG. (4 to 9 nm), but these pores
are intended to be those measured by nitrogen adsorption.
[0009] Texaco Sudhakar (U.S. Pat. No. 5,624,547) describes an
activated carbon catalyst, but discloses that this catalyst is used
after treatment with phosphoric acid or together with a metal on
the activated carbon itself.
[0010] The subject of treatment in the US publication is
distillates of less than 350.degree. C., that is, gas oil.
[0011] Any of the above shown publications are concerned with
activated carbon having those physical properties (e.g., specific
surface area, pore volume, and average pore size) of pores which
were measured by a nitrogen adsorption method.
[0012] JP-A 2001-9282, being equivalent to DE-A 10020723, describes
a method of hydrocracking heavy oil as a subject of treatment by a
catalyst characterized by those physical properties of pores which
were measured by the same nitrogen adsorption method as above.
DISCLOSURE OF THE INVENTION
[0013] Because a catalyst is used in fluid catalytic cracking or
hydrocracking, the content of nickel and vanadium and the content
of residual carbon in heavy oil as a raw oil are limited. Coke is
formed in the process of fluid catalytic cracking reaction where
the amount of coke accumulated on the catalyst is increased in
proportion to the content of residual carbon in the raw oil. In a
regeneration tower, the catalyst is regenerated by burning the
coke, but when the amount of accumulated coke is large, the
temperature in the regeneration tower is increased to deteriorate
the catalyst. Nickel and particularly vanadium destroy the
crystalline structure of zeolite to deteriorate the activity.
[0014] The process of removing asphaltene and impurities such as
nickel and vanadium with a solvent is a method of merely separating
asphaltene, and thus asphaltene in the raw oil is separated as it
is, and therefore, as the raw oil becomes heavy, the amount of
asphaltene after separation is increased to make use thereof
problematic.
[0015] In the hydrocracking process, an alumina supported catalyst
is usually used, and pores are designed to have a relatively large
size in order to reduce the clogging of catalyst pores with
accumulated nickel and vanadium, but as described by Speight, J. G.
in The Chemistry and Technology of Petroleum, Marcel Dekker (1980),
acidic sites of the original alumina carrier are effective in
hydrocracking activity, but are poisoned by a basic compound
contained in heavy oil. Activated carbon has less acidic sites than
in the alumina catalyst, and metal oxides carried on the activated
carbon carrier can be easily activated.
[0016] As described by Godfried M. K. Abotsi and Alan W. Scanroni
in Fuel Processing Technology, 22, pp 107-133 (1989), alumina is
problematic in that a metal oxide carried on the carrier is hardly
reduced to form an active metal species.
[0017] The means to solve the problem is as follows:
[0018] In the prior patent publications above cited, some of the
physical properties of pores in activated carbon, that is, specific
surface area, pore volume and average pore size are measured by the
nitrogen adsorption method, and the effectiveness of pores with
diameter in the range of up to about 100 nm (1000 .ANG.
(angstroms)) measured by the nitrogen adsorption method is
described. In the present application, on the other hand, a
distribution of larger pores, not measured by the conventional
nitrogen adsorption method, which were given to activated carbon
obtained by molding with an extrusion molding machine etc. is
prescribed by mercury porosimetry. It is an object of the invention
to enable a method effective in hydrocracking of heavy oil. By
giving the larger pores, asphaltene contained in heavy oil of high
molecular size, and heavy fractions containing impurities such as
heavy nickel and vanadium, are easily diffused into pores of
activated carbon thereby effectively removing and capturing heavy
metals such as nickel and vanadium.
[0019] The invention provides a method of hydrocracking heavy oil,
comprising the step of hydrocracking heavy oil in a fixed bed, a
moving bed or an ebullating bed with a hydrocracking catalyst
comprising activated carbon extrudate as a carrier activated with
steam and having a high distribution of pores having pore diameter
in the range of 20 to 200 nm and any one of the group VIIIB metals
selected from iron, nickel and cobalt or molybdenum, both nickel
and molybdenum, or both cobalt and molybdenum, under the conditions
of a pressure of 8 to 20 MPa, a temperature of 380 to 450.degree.
C., an LHSV of 0.1 to 1.0 hr.sup.-1, and an H.sub.2/oil ratio of
350 to 1500 Nm.sup.3/kl-oil.
[0020] Herein, LHSV is the Liquid Hourly Space Velocity, expressed
in liters-feed per liters-catalyst, per hour. Nm.sup.3/kl means
Standard cubic meters (H.sub.2) per kilo-liters (oil).
[0021] The present invention provides a hydrocracking catalyst
comprising activated carbon extrudate as a carrier activated with
steam and having a high distribution of pores having pore diameter
in the range of 20 to 200 nm and any one of the group VIIIB metals
selected from iron, nickel and cobalt or molybdenum, both nickel
and molybdenum, or both cobalt and molybdenum.
[0022] The invention provides a hydrocracking catalyst, comprising
activated carbon extrudate as a carrier, activated with steam, and
having a pore size distribution with a high proportion of pores
having pore diameter in the range of 20 to 200 nm, the pore size
distribution particularly having a peak; and any one of the group
VIII metals selected from iron, nickel, and cobalt, or molybdenum;
both nickel and molybdenum; or both cobalt and molybdenum.
[0023] The invention provides a process of manufacturing a
hydrocracking catalyst, comprising the steps of providing a
starting carbon source, grinding said starting carbon source into
fine particles; preparing an extrudable mixture from said fine
particles; molding the material by extruding; activating the
extrudate with an activating gas; and converting the activated
carbon extrudate into the catalyst by adding a catalyzing metal or
metal compound; characterized in that said activating gas comprises
steam and optionally air, such that the oxygen content is not more
than 6 vol %.
[0024] The invention provides a catalyst obtainable by the above
shown process. The catalyst may be used in the hydrocracking
method.
[0025] The invention provides use of the above shown catalyst for
hydrocracking a heavy oil.
[0026] The present invention makes use of an activated carbon
catalyst thereby adsorbing and cracking asphaltene contained in
heavy oil, effectively removing impurities such as nickel and
vanadium, and enabling hydrocracking with less formation of
coke.
[0027] That is, the advantages of the present invention are as
follows:
[0028] Activated carbon has affinity for heavy fractions and
selectively adsorbs asphaltene containing a large amount of
impurities such as nickel and vanadium.
[0029] Activated carbon has a relatively large pore size to
facilitate diffusion of heavy fractions containing e.g. asphaltene
of large molecular weight into pores.
[0030] Unstable hydrocarbon radicals formed by cracking of heavy
oil containing a large amount of asphaltene are hydrogenated so
that the chain reaction of the hydrocarbon radicals is regulated
and the formation of coke by the polycondensation reaction of the
hydrocarbon radicals is inhibited.
[0031] Acidic sites of the conventional alumina supported catalyst
are poisoned by basic compounds contained in heavy oil so that the
activity is significantly lowered thus resulting in formation of
coke, whereas activated carbon has less acidic sites and thus the
activity is hardly lowered.
[0032] Activated carbon has a high specific area to permit an
active metal for hydrogenation to be highly dispersed and carried
thereon.
[0033] The highly dispersed metal oxide can be activated more
easily than the alumina catalyst, and the carried metal species is
effectively used.
[0034] Activated carbon has a large volume of pores to exhibit high
tolerance to accumulation of nickel and vanadium removed from raw
oil.
[0035] Accordingly, the activated carbon catalyst is effective as a
catalyst forming less coke, incorporating a larger amount of
removed heavy metal, and undergoing less deterioration in the
hydrocracking reaction of heavy oil than the conventional
catalyst.
[0036] Further, the used activated carbon catalyst having nickel
and vanadium accumulated thereon can be subjected to burning
treatment to recover nickel and vanadium easily.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is an illustration showing a general process of
producing activated carbon extrudate;
[0038] FIG. 2 is a graph showing a distribution of pore sizes in
activated carbon;
[0039] FIG. 3 is an illustration showing an autoclave;
[0040] FIG. 4 is an illustration showing an ebullating bed reaction
unit used in the present invention;
[0041] FIG. 5 is an illustration showing a fixed bed reaction unit
(A) used in the present invention; and
[0042] FIG. 6 is an illustration showing a fixed bed reaction unit
(B) used in the present invention.
DETAILED EXPLANATION OF THE INVENTION
[0043] Hereinafter, the present invention is described in more
detail. The catalyst of the invention is a hydrocracking catalyst
comprising activated carbon extrudate as a carrier activated with
steam and having a high distribution of pores having pore diameter
in the range of 20 to 200 nm, which is preferably a hydrocracking
catalyst having activated carbon as a carrier prepared by molding
Australian Yalloum brown coal as a carbon source in an extrusion
molding machine and then activating it with steam.
[0044] Preferably effective in hydrocracking is a hydrocracking
catalyst comprising activated carbon extrudate as a carrier,
wherein the volume of pores determined by mercury porosimetry is
0.7 to 1.8 ml/g, more preferably 0.8 to 1.6 ml/g, even more
preferably 1.05 to 1.55 ml/g, the proportion of pores having pore
diameter in the range of 20 to 200 nm is 20 vol % or more, more
preferably 25 vol % or more, even more preferably 30 vol % or more,
and the ratio by volume of pores having pore diameter in the range
of 38 to 90 nm to pores having pore diameter in the range of 20 to
200 nm is 40% or more, more preferably 43% or more, even more
preferably 45% or more.
[0045] Preferably effective in hydrocracking is a hydrocracking
catalyst comprising activated carbon extrudate as a carrier,
wherein the differential pore size distribution has a peak, said
peak being in the pore size range 20 to 200 nm, more preferably in
the pore size range 38 to 90 nm, even more preferably in the pore
size range 40 to 60 nm, said peak having a height of at least 0.4
cm.sup.3/g, more preferably at least 0.5 cm.sup.3/g, even more
preferably at least 0.6 cm.sup.3/g.
[0046] More preferable is a catalyst using activated carbon whose
ability to adsorb asphaltene is 22%/ml or more, having the same
properties as above in view of the volume of pores determined by
mercury porosimetry, the proportion of pores having pore diameter
in the range of 20 to 200 nm and the ratio by volume of pores
having pore diameter in the range of 38 to 90 nm to pores having
pore diameter in the range of 20 to 200 nm.
[0047] Any one of the group VIIIB metals such as iron, nickel and
cobalt, or molybdenum, both nickel and molybdenum, or both cobalt
and molybdenum are carried on activated carbon to form the
catalyst.
[0048] The group VIIIB metals preferably include iron, nickel or
cobalt.
[0049] The catalyst component may be selected from any one of the
group VIIIB metals, molybdenum, a mixture of nickel and molybdenum
and a mixture of cobalt and molybdenum.
[0050] The present invention also relates to a method of
hydrocracking heavy oil in a fixed bed, a moving bed or a
ebullating bed with the hydrocracking catalyst under the conditions
of a pressure of 8 to 20 MPa, a temperature of 380 to 450.degree.
C., an LHSV of 0.1 to 1.0 hr.sup.-1, and an H.sub.2/oil ratio of
350 to 1500 Nm.sup.3/kl-oil. Preferably, the heavy oil used in this
method is a hydrocarbon oil containing 70 vol % fraction or more
with the boiling point at 525.degree. C. or more, a hydrocarbon oil
containing at least 200 to 2000 wppm nickel and/or vanadium as
heavy metal, or a hydrocarbon oil containing 8 to 30 wt %
asphaltene (heptane insolubles).
[0051] Method of Producing Activated Carbon
[0052] Activated carbon extrudate is produced by a general method.
The starting carbon source of activated carbon includes charcoal,
coconut shell carbon, peat, lignite, brown coal, bituminous coal,
petroleum cokes, etc. FIG. 1 shows a method of producing activated
carbon extrudate. The starting carbon source is roughly ground into
course particles of 8/32 mesh size and then devolatalized at 200 to
300.degree. C., and the devolatalized product is then finely ground
until the content of fine particles of not greater than 280 mesh
size reaches 75 to 85 wt % or more. About 0.5 part of a binder such
as tar, pitch and starch is mixed with 1 part of the devolatalized
product, then water is added in a water content of 10 to 20% by
weight, and the mixture is kneaded uniformly. The material is
molded by extruding it at a pressure of 300 to 600 MPa through a
die arranged in an extrusion molding machine. The opening diameter
of the die is selected depending on the use of activated carbon,
and in this example, a die having a diameter of 1 mm was used.
[0053] To activate the activated carbon extrudate, a method of
using a rotary kiln is generally known. The activating gas used may
be steam, carbon dioxide, air or a mixed fluid thereof, but carbon
dioxide is poor in reactivity, thus requiring a longer time for
activation, and is effective in development of only micropores of 2
nm or less.
[0054] It is preferable that the activating gas comprises steam and
optionally air, such that the oxygen content is not more than 4 vol
%.
[0055] Air can also be mixed, but when air is mixed such that the
amount of oxygen is higher than 4 vol %, 50 nm or more macropores
are merely increased, and the ratio by volume of pores having pore
sizes in the range of 38 to 90 nm to pores having pore sizes in the
range of 20 to 200 nm in the present invention is decreased. In the
present invention, steam which is highly reactive and can achieve
the distribution of pores having the most suitable size for the
present invention is more preferable. First, the extruded product
is dried at about 140.degree. C. in air or a combustion gas and
then carbonized at 400 to 600.degree. C., and then the resulting
carbonized material are fed to a rotary kiln and activated with
steam at a temperature of 800 to 950.degree. C. In these steps, the
extruded product becomes activated carbon having a diameter (.phi.)
of 1 mm and a length (L) of 3 to 8 mm. The optimum activation time
is selected depending on the easiness of activation of the starting
carbon source, the intended pore volume, specific surface area,
pore distribution etc. That is, when the activation time is short,
pores are undeveloped. When the activation time is increased, the
crushing strength of the resulting activated carbon is lowered to
cause a problem that the activated carbon cannot endure industrial
use or the yield is decreased to bring about an economic
disadvantage. The standard activation time used in the present
invention is preferably 4 to 12 hours, more preferably 6 to 9
hours. The extrudate may be again activated with the activated
carbon for an additional 2 to 8 hours, more preferably about 3 to 5
hours.
[0056] Pores having a radius of 50 nm or less in the activated
carbon thus prepared were measured for their physical properties
such as specific surface area and pore volume by a BET nitrogen
adsorption method and for their pore size distribution and average
pore diameter by a B. J. Hmethod. Pores having a radius in the
range of 3.2 to 100,000 nm were measured for their pore volume and
pore size distribution (with Autopore III9420 unit manufactured by
MICROMERITICS) by mercury porosimetry.
[0057] Ability to Adsorb Asphaltene
[0058] Heavy oil contains a large amount of asphaltene, and this
asphaltene contains impurities such as sulfur and nitrogen and
heavy metals such as nickel and vanadium. Asphaltene is a compound
of relatively high molecular weight, and the easiness of adsorption
of asphaltene into the catalyst and diffusion thereof into pores is
important for hydrocracking of heavy oil.
[0059] Now, the ability of various kinds of activated carbon to
adsorb asphaltene was examined in the following adsorption test. 20
g vacuum residual oil and 1 g activated carbon were placed in a
glass container. Several glass containers containing similarly
prepared different kinds of activated carbon were placed in a 1 L
autoclave shown in FIG. 3 and then kept under the conditions of a
hydrogen pressure of 10 MPa and a temperature of 250.degree. C. for
2 hours, and then cooled and depressurized, and these glass
containers were removed, and the activated carbon therein was
separated from the vacuum residual oil by filtration. The
concentration of asphaltene in the vacuum residual oil after
separation was determined, and on the basis of the difference of
this determined concentration from the concentration of asphaltene
in the original vacuum residual oil, the weight amount of
asphaltene adsorbed into each activated carbon was determined, and
the weight amount of asphaltene adsorbed per unit weight of
activated carbon per unit volume of pores was regarded as the
ability to adsorb asphaltene, and the abilities of various kinds of
activated carbon were compared. Normal heptane (nC7) insolubles
were regarded as asphaltene, and the concentration thereof was
measured according to ASTM D3279. The vacuum residual oil was from
the Middle East crude, and had the following main properties: API
5.35; 22.4 wt % CCR (carbon residue), 4.02 wt % sulfur, 0.53 wt %
nitrogen, 53 wppm nickel, 180 wppm vanadium and 9.08 wt %
asphaltene (nC7 Insols.).
[0060] API refers to API gravity, and CCR refers to Conradson
carbon residue. The "wppm" given to nickel and vanadium is a unit
on a weight basis.
[0061] The result indicated that the activated carbon having an
absolute value of pore volume in the range of 0.8 ml/g or more and
having a high distribution of pores with the diameter in the range
of 20 to 200 nm was excellent in the ability to adsorb
asphaltene.
[0062] Conversion of the Activated Carbon Extrudate into a
Catalyst
[0063] The method of permitting the activated carbon to carry metal
was conducted by a generally known method of
impregnation/evaporation into dryness with an aqueous solution of a
metal nitrate compound, and thereafter, the nitrate was pyrolyzed
in a nitrogen atmosphere, whereby a catalyst carrying metal thereon
was obtained.
[0064] Now, one example where iron is carried on the catalyst is
described. 50 g activated carbon extrudate and 350 ml distilled
water are introduced into a 1 L separable flask and degassed at
room temperature for 30 minutes at a reduced pressure of 10 torr.
Ferric nitrate.9H.sub.2O (Fe(NO.sub.3).sub.3.9H.sub.2O) is weighed
in such a predetermined amount that the amount of the carried metal
is 10 wt % relative to the activated carbon extrudate, followed by
adding distilled water thereto to prepare an aqueous solution.
Preferably, 36.173 g ferric nitrate is dissolved in 150 g distilled
water, and the activated carbon extrudate previously degassed under
reduced pressure is added thereto. This aqueous solution containing
the activated carbon extrudate is heated to 80 to 90.degree. C.
under stirring in a hot water bath and evaporated into dryness
until water disappears. The resulting product is vacuum-dried at
130.degree. C., 10 torr, for 1 hour. The resulting activated carbon
extrudate having iron carried thereon is packed in a quartz tube
and kept at 150.degree. C. for 1 hour in a nitrogen stream, to
eliminate water completely. Subsequently, the sample was heated to
450.degree. C. and kept at 1 hour thereby decomposing the nitrate,
to give a catalyst.
[0065] When a metal is to be carried, a method of using an
oil-soluble metal can also be used.
[0066] Ability to Suppress Formation of Coke
[0067] In the process of hydrocracking reaction, a bond of
hydrocarbon having a relatively high molecular weight is cleaved to
generate a hydrocarbon radical. This hydrocarbon radical is highly
reactive and causes chain reaction, thus leading to the extreme
progress of the reaction of forming light products by cracking in
one hand and the progress of the polycondensation reaction of
mutually bonding hydrocarbon radicals on the other hand, resulting
in loss of the phase equilibrium of liquid components to
precipitate high-molecular distillates as sediment by phase
separation. A unit or pipe is contaminated or clogged with the
precipitated or settled sediment, thus hindering operation in
hydrocracking facilities.
[0068] With respect to the distribution of products, gas is
generated in a larger amount by overcracking reaction of light
products, and the yield of desired distillates such as naphtha,
kerosene and light oil is reduced, while coke is formed finally by
the polycondensation reaction.
[0069] Now, the catalyst prepared by carrying iron on activated
carbon extrudate was used in a hydrocracking test in a 1 L
autoclave shown in FIG. 3, and the amount of coke formed by the
hydrocracking reaction was quantified.
[0070] About 200 g vacuum residual oil and the activated carbon
extrudate catalyst in an amount of 10 wt % relative to the vacuum
residual oil were charged into an autoclave shown in FIG. 3, then
pressurized with hydrogen at 10 MPa, heated to 400 to 430.degree.
C. and subjected to hydrocracking for a predetermined time (1 to 3
hours). After the reaction was finished, the whole material in the
autoclave was filtered with a 5-micron filter, and the solids
(residues) remaining on the filter were extracted with toluene in a
Soxhlet extractor. The remaining solids on the filter were
vacuum-dried at 8 to 15 torr at 130.degree. C. for a predetermined
time, then measured for their weight, and quantified as toluene
insolubles, and the difference of the measured weight from the
weight of the initially charged activated carbon extrudate catalyst
was regarded as the amount of coke formed. The weight percentage of
the determined amount of formed coke, relative to the vacuum
residual oil charged into the autoclave before the reaction, was
expressed as the degree of formation of coke. The degrees of
formation of coke at the same degree of conversion by the
hydrocracking reaction were compared. A lower degree of formation
of coke is indicative of a higher ability to suppress formation of
coke.
[0071] The degree of conversion and the degree of formation of coke
are defined as follows:
[0072] Degree of conversion (wt %)=100.times.(gas+the fraction with
the boiling point at 525.degree. C. or more in hydrocracked oil)
(weight)/the fraction with the boiling point at 525.degree. C. or
more in vacuum residual oil charged (weight)
[0073] Degree of formation of coke (wt %)=100.times.(amount of coke
formed) (weight)/vacuum residual oil charged (weight)
EXAMPLES
[0074] Hereinafter, the present invention is described in more
detail by reference to the Examples.
Example 1
[0075] Various kinds of activated carbon were prepared by the
above-described method of producing activated carbon extrudate.
[0076] The states of Preparations 1, 2 and 3 prepared in Examples
1-1,1-2 and 1-3 from Yalloum brown coal as the starting carbon
source by changing the activation time are shown in Table 1.
Commercial Product 1 in Comparative Example 1-1 and Commercial
Product 2 in Comparative Example 1-2 are commercial activated
carbon made of peat, and Commercial Product 3 in Example 1-4 is
produced by activating Comparative Product 2 (activated carbon)
again with steam for 3 hours to change its pore structure.
Australian Yalloum brown coal could be used as the carbon source to
produce activated carbon wherein the ratio by volume of pores
having pore diameter in the range of 38 to 90 nm to pores having
pore diameter in the range of 20 to 200 nm was 45% or more.
[0077] A patent application (JP-A2001-9282) concerning activated
carbon as a catalyst for hydrocracking of heavy oils, filed by the
present inventors, is milled activated carbon obtained by milling
Yalloum brown coal as the carbon source and activating it without
molding with a binder etc. The states of this milled activated
carbon are shown in Comparative Example 1-3, where the proportion
of pores having pore diameter in the range of 20 to 200 nm was as
high as 40 vol %, but the ratio by volume of pores having pore
diameter in the range of 38 to 90 nm to pores having pore diameter
in the range of 20 to 200 nm was as low as 37%.
[0078] The distribution of pore sizes in these activated carbon
samples is shown in FIG. 2.
[0079] In the invention, the catalyst may has a pore size
distribution with a high proportion, peak or maximum, of pores
having pore diameter in the range of 20 to 200 nm.
[0080] As shown in the distribution of pore sizes in FIG. 2, the
activated carbon extrudate samples in Examples 1-1,1-2, 1-3 and 1-4
have a peak in distribution of pore diameter in the range of 38 to
90 nm, while the milled activated carbon in Comparative Example 1-3
has a merely broad distribution of pore diameter in the range of 20
to 200 nm and is different in distribution of pore sizes from the
activated carbon extrudate samples of the present invention. As
shown in Example 1-4, the same activated carbon extrudate as in
Example 1-1,1-2 and 1-3 could be prepared by activating commercial
activated carbon extrudate for a longer time. However, the
activated carbon extrudate samples made of Yalloum brown coal in
Examples 1-1,1-2 and 1-3 are superior in the peak of pore
distribution (the proportion by volume of pores having pore
diameter in the range of 20 to 200 nm, and the ratio by volume of
pores having pore diameter in the range of 38 to 90 nm to pores
having pore diameter in the range of 20 to 200 nm).
1 TABLE 1 Comparative Comparative Comparative Example 1-1 Example
1-2 Example 1-4 Example 1-1 Example 1-2 Example 1-3 Example 1-3
Activated carbon extrudate Commercial Commercial Commercial
Preparation Preparation Preparation Milled product product 1
product 2 product 3 product 1 product 2 product 3 Activation time
(h) -- Base Base + 3 6 7 9 2 Size 0.8 mm .phi. .times. 0.8 mm .phi.
.times. 0.8 mm .phi. .times. 1 mm .phi. .times. 1 mm .phi. .times.
1 mm .phi. .times. 1.2-2 mm 3-8 mmL 3-8 mmL 3-8 mmL 3-8 mmL 3-8 mmL
3-8 mmL Pore volume (ml/g) 0.38 0.68 1.09 0.82 1.06 1.54 0.89 by
mercury porosimetry Proportion (%) of 5 18.8 30 36 37 40 40 pores
of 20-200 nm Ratio (%) of pores of 38 to 90 nm 30 40 45 56 54 50 37
to pores of 20 to 200 nm Bulk density (g/ml) 0.53 0.4 0.3 0.36 0.3
0.25 0.4 Abrasive strength (wt. %) 98.8 98 97.4 99.2 98.3 98.6 96
(ASTM D4058) Crushing strength (kg/mm) 0.36 0.35 0.3 0.46 0.35 0.28
0.4 (ASTM D6175)
Example 2
[0081] The ability of activated carbon to adsorb asphaltene was
examined by the method described above for the ability to adsorb
asphaltene.
[0082] Table 2 shows physical properties of activated carbon
extrudate not carrying metal.
[0083] The vacuum residual oil was from the Middle East crude, and
had the following main properties: API 5.35; 22.4 wt % CCR (carbon
residue), 4.02 wt % sulfur, 0.53 wt % nitrogen, 53 wppm nickel, 180
wppm vanadium and 9.08 wt % asphaltene (nC7 Insols.).
[0084] As can be seen from Table 2, it was found that the activated
carbon extrudate having pores with an absolute value of pore volume
in the range of 0.8 ml/g or more wherein the proportion of pores
having pore diameter in the range of 20 to 200 nm is 30 vol % or
more, and the ratio by volume of pores having pore diameter in the
range of 38 to 90 nm to pores having pore diameter in the range of
20 to 200 nm is 45% or more is also excellent in the ability to
adsorb asphaltene.
2 TABLE 2 Comparative Comparative Comparative Example 2-1 Example
2-2 Example 2-4 Example 2-1 Example 2-2 Example 2-3 Example 2-3
Activated carbon extrudate Commercial Commercial Commercial
Preparation Preparation Preparation Milled product product 1
product 2 product 3 product 1 product 2 product 3 Activation time
(h) -- Base Base + 3 6 7 9 2 Size 0.8 mm .phi. .times. 0.8 mm .phi.
.times. 0.8 mm .phi. .times. 1 mm .phi. .times. 1 mm .phi. .times.
1 mm .phi. .times. 1.2-2 mm 3-8 mmL 3-8 mmL 3-8 mmL 3-8 mmL 3-8 mmL
3-8 mmL Pore volume (ml/g) 0.38 0.68 1.09 0.82 1.06 1.54 0.89 by
mercury porosimetry Proportion (%) of 5 18.8 30 36 37 40 40 pores
of 20-200 nm Ratio (%) of pores of 38 to 90 30 40 45 56 54 50 37 nm
to pores of 20 to 200 nm Ability to adsorb 3 18 25 22 27 34 21
asphaltene (%/ml)
Example 3
[0085] Activated carbon catalysts were prepared by the method
described above for conversion of activated carbon extrudate into a
catalyst, and the abilities of the activated carbon catalysts to
suppress formation of coke were compared and evaluated by the
method described above for the ability to suppress formation of
coke.
[0086] The vacuum residual oil was from the Middle East crude, and
had the following main properties: API 5.35; 22.4 wt % CCR (carbon
residue), 4.02 wt % sulfur, 0.53 wt % nitrogen, 53 wppm nickel, 180
wppm vanadium and 9.08 wt % asphaltene (nC7 Insols.).
[0087] As shown in Table 3, it was found that the activated carbon
extrudate having pores with an absolute value of pore volume in the
range of 0.8 ml/g or more wherein the proportion of pores having
pore diameter in the range of 20 to 200 nm is 30 vol % or more, the
ratio by volume of pores having pore diameter in the range of 38 to
90 nm to pores having pore diameter in the range of 20 to 200 nm is
45% or more, and the ability of the activated carbon to adsorb
asphaltene is 22%/ml or more, exhibits a high ability to suppress
formation of coke.
3 TABLE 3 Comparative Comparative Comparative Example 3-1 Example
3-2 Example 3-3 Example 3-1 Example 3-2 Example 3-4 Example 3-3
Catalyst YA-1 YA-2 YA-3 NR-1 NR-2 NR-3 YA-0 Carried metal/wt. %
iron/10 iron/10 iron/10 iron/10 iron/10 iron/10 iron/10 Activated
carbon Preparation Preparation Preparation Commercial Commercial
Commercial Milled product product 1 product 2 product 3 product 1
product 2 product 3 Pore volume (ml/g) 0.82 1.06 1.54 0.38 0.68
1.09 0.89 Proportion (%) of 36 37 40 5.0 18.8 30 40 pores of 20-200
nm Ability to adsorb 22 27 34 3 18 25 21 asphaltene (%/ml) Ratio
(%) of pores of 38 56 54 50 30 40 45 37 to 90 nm to pores of 20 to
200 nm Carried metal iron iron iron iron iron iron iron Amount of
carried metal (wt. %) 10 10 10 10 10 10 10 Degree of conversion (wt
%) 81 82 84 80 82 81 80 Degree of formation of 6.8 6.2 5.5 12 9 6.9
7.5 coke (wt %) Raw oil: Vacuum residual oil from the Middle East
Crude API: 5.35, CCR: 22.4 wt. %, nC7Insol.: 9.08 wt. %, S: 4.02
wt. %, N: 0.53 wt. %, Ni: 53 wppm, V: 180 wppm Pressure: 10 Mpa,
Temperature: 425.degree. C., Time: 90 minutes
Example 4
[0088] FIG. 4 shows an ebullating bed reaction unit. Reactors each
having an internal volume of 1 L charged with a catalyst are
arranged in series. The system is charged with light oil such as
gas oil. By a hydrogen compressor (1), hydrogen is introduced into
the system, and the system is kept at a predetermined pressure by a
gas pressure regulating valve (19). A gas oil is circulated by
circulating pumps (5) and (7) to fluidize the catalyst charged in
ebullating bed reactors (4) and (6), while the system is heated to
an allowable temperature for vacuum residual oil. Vacuum residual
oil is fed through a raw oil feed pump (3) from a raw oil tank (2)
and heated to a predetermined reaction temperature to initiate
hydrocracking reaction. From the effluent from the reactor, heavy
distillates are separated in a high-temperature high-pressure
separator (8), and after gas is separated in a low-pressure
separator (12), the heavy distillates are sent to a heavy
distillate reservoir (14). Light distillates separated in the
high-temperature high-pressure separator (8) are separated from gas
in a low-pressure high-temperature separator (10), and in a
separator (15), the light distillates are separated from water
injected into the line, and the water is sent to a condensed water
reservoir (16), while the light distillates are sent to a light
distillate reservoir (17). From the gas separated in each
separator, hydrogen sulfide is separated in a gas washing column
(20), measured for its flow rate and then discharged into the
outside of the system.
[0089] In the unit having two 1 L ebullating bed reactors connected
in series shown in FIG. 4, the hydrocracking ability of the
activated carbon extruded catalyst carrying iron was examined. The
results in Example 4 are shown in Table 4 in comparison to the
performance of a commercial alumina catalyst in similar ebullating
bed reactors.
[0090] When the activated carbon catalyst YA-1 in Example 4-1 and
the commercial alumina catalyst in Comparative Example 4-1 were
compared at the same degree of conversion, the activated carbon
catalyst YA-1 showed a higher degree of removal of metal and a
lower amount of sediment. The degree of conversion in Example 4-2
was 64 wt % which is higher than the degree of conversion (55 wt %)
in Comparative Example 4-1, and the amount of sediment was 0.8%
which is lower than 0.9% in Comparative Example 4-1, thus
indicating that a higher degree of conversion could be achieved by
using the activated carbon catalyst.
4 Example 4-1 Example 4-2 Example 4-3 Comparative Example 4-1
Catalyst YA-1 YA-1 YA-1 Commercail alumina catalyst Carried
metal/wt. % iron/10 iron/10 iron/10 nickel/2.5, molybdenum/9.5
Temperature (.degree. C.) 415 419 422 415 Degree of conversion (wt
%) 55 64 71 55 Degree of desulfurization (%) 42 49 51 70 Degree of
removal of metal (%) 77 84 88 65 Sediment (%) (ASTM D4870) 0.28 0.8
1.1 0.9 Raw oil: Mixture of Maya/Isthmus vacuum residual oil API:
3.73, CCR: 22.6 wt. %, nC7Insol.: 17.8 wt. %, S: 4.51 wt. %, N:
0.61 wt. %, Ni: 84 wppm, V: 418 wppm Pressure: 18.5 Mpa, LHSV: 0.3
hr.sup.-1, H.sub.2/Oil ratio: 1335 Nm.sup.3/kl-oil
[0091] Degree of desulfurization (%)=100.times.weight of hydrogen
sulfide in gas/weight of sulfur in raw oil
[0092] Degree of removal of metal (%)=100.times.weight of
(nickel+vanadium) in hydrocracked oil/weight of (nickel+vanadium)
in raw oil
Example 5
[0093] FIG. 5 shows a fixed bed reaction unit (A). Four fixed bed
reactors (204) charged with catalysts (each volume 120 cc) are
heated with the same aluminum block heater. Hydrogen is introduced
through a regulating valve (201) into the system, and the pressure
in the system is kept constant with a back pressure regulating
valve (208). A raw oil in a raw oil tank (202) is fed by a raw oil
feed pump (203) to a fixed bed reactor (204). From an effluent from
the reactor, gas is separated in a high-temperature high-pressure
separator (205), and the hydrocracked oil is sent to a cracked oil
tank (207). The separated gas is discharged via a back pressure
regulating valve (208) into the outside of the system.
[0094] The four reactors (each having a volume of 120 cc) shown in
FIG. 5 are arranged in parallel, and hydrocracking shown in Table 5
is conducted by the fixed bed reaction unit placed in the same
heating furnace to compare the performance of the activated carbon
extrudate YA-1 carrying iron with that of a commercial alumina
catalyst. The activated carbon catalyst YA-1 and the commercial
alumina catalyst used were taken out after 100 hours of test, and
one typical catalyst particle was embedded with resin and its cross
section was polished and examined for the distribution of
concentration of vanadium across the cross section by an electron
probe microanalyzer (EPMA) method with EPMA2000 (accelerating
voltage, 15 kV; beam size, 3 .mu.m.phi.; step size, horizon 3 .mu.m
and vertical 3 aim) manufactured by Shimadzu Corporation. When the
distribution of vanadium on the basis of this result is expressed
in terms of the ratio of the concentration of vanadium on the
surface of the catalyst particle to the concentration of vanadium
in the center of the particle, the concentration ratio in the
activated carbon extrudate catalyst YA-1 in Example 5-2 is 2.2
which is lower than the concentration ratio (23) in the commercial
alumina catalyst in Comparative Example 5-1, thus indicating that
vanadium is distributed uniformly from the surface to center of the
particle. In the commercial alumina catalyst, pores are clogged
with vanadium accumulated on the surface of the particle, and thus
pores in the center are not effectively used, but in the activated
carbon extrudate catalyst, asphaltene is diffused into pores, and
the whole of the pores in the catalyst particle are used
effectively to remove vanadium.
[0095] While iron was carried on the activated carbon extrudate
catalyst YA-1 in Example 5-2, nickel and molybdenum were carried on
the activated carbon extrudate catalyst YA-1X in Example 5-1, and
succeeded in improving the degree of desulfurization without
changing other performance.
5 TABLE 5 Example 5-1 Example 5-2 Comparative Example 5-1 Catalyst
YA-1X YA-1 Commercail alumina catalyst Carried metal/wt. %
nickel/2.8, iron/10 nickel/2.5, molybdenum/9.5 molybdenum/9.0
Degree of conversion (wt %) 65 64 73 Degree of desulfurization (%)
67 53 95 Degree of removal of nickel (%) 82 86 96 Degree of removal
of vanadium (%) 96 96 99 Ratio of vanadium concentration (-) 2.4
2.2 23 catalyst-particle surface/ catalyst-particle center Sediment
(%) 0.003 <0.001 0.07 Raw oil: Mixture of Maya/Mesa/Arabian
light crudes vacuum residual oil API: 5.9, CCR: 20.8 wt. %, S: 5.1
wt. %, N: 0.38 wt. %, Ni: 75 wppm, V: 340 wppm Pressure: 18.5 Mpa,
Temperature: 422.degree. C., LHSV: 0.25 hr.sup.-1, H.sub.2/Oil
ratio: 935 Nm.sup.3/kl-oil
Example 6
[0096] FIG. 6 shows a fixed bed reaction unit (B). A reactor (306)
(volume 700 cc) is charged with a catalyst, and hydrogen from a
cylinder is depressurized with a regulating valve (301), and
hydrogen is transferred via a hydrogen buffer tank (302) and sent
at a predetermined rate with a flow controller (313). The pressure
in the system is kept constant with a back pressure regulating
valve (309). A raw oil in a raw oil tank (304) is fed by a raw oil
feed pump (305) to a fixed bed reactor (306). From an effluent from
the reactor, gas is separated in a high-temperature high-pressure
separator (307), and the gas is depressurized to the atmospheric
pressure via the back pressure regulating valve (309), and a small
amount of cracked light oil are separated in a light cracked oil
reservoir (310) and then transferred via a hydrogen sulfide remover
(311) and measured for the amount of gas with a gas meter (312),
and the gas is discharged to the outside of the system. The cracked
heavy oil separated in the high-temperature high-pressure separator
(307) is sent to a heavy cracked oil reservoir (308).
[0097] By the fixed bed reaction unit (B) (internal volume 700 cc)
shown in FIG. 6, the deactivation behavior of the activated carbon
extrudate catalyst YA-3.times.shown in Table 6 was compared with
that of a commercial alumina catalyst by carrying out a
hydrocracking reaction. When the amounts of nickel and vanadium
accumulated on each catalyst reached 5% and 30% respectively
relative to the weight of the new catalyst, each catalyst was
examined for the degree of conversion, the degree of
desulfurization and the degree of removal of metal. By comparing
reductions in the degree of conversion, the degree of
desulfurization and the degree of removal of metal, the activity of
the activated carbon extrudate catalyst YA-3.times.in Example 6-1
was hardly reduced, while the activity of the commercial alumina
catalyst in Comparative Example 6-1 was significantly reduced.
6 Example 6-1 Comparative Example 6-1 Catalyst YA-3X Commercail
alumina catalyst Carried metal/wt. % nickel/1.7, molybdenum/7.0
nickel/2.5, molybdenum/9.5 Accumulated metal wt. (% relative to new
catalyst) 5 30 5 30 Degree of conversion (wt %) 52 48 50 40
Reduction (%) in hydrocracking activity -- 8 -- 20 Degree of
desulfurization (%) 40 38 62 52 Reduction (%) in desulfurization
activity -- 5 -- 16 Degree of removal of metal (%) 65 64 78 76
Reduction (%) in degree of activity of removal of metal -- 1 -- 2.6
Raw oil Mixed Maya vacuum Maya vacuum residual oil residual oil
API: 2.39, CCR: 25.04 wt. API: 4.56, CCR: 22.66 %, nC7Insols.:
22.59 wt. wt. %, nC7Insols.: 20.57 %, S: 5.88 wt. %, Ni: wt. %, S:
5.01 wt. %, 127 wppm, V: 583 wppm N: 0.608 wt. %, Ni: 113 wppm, V:
551 wppm Hydrocracking conditions 12 Mpa, 432.degree. C., 12 Mpa,
420.degree. C., LHSV: 0.5 hr.sup.-1 LHSV: 0.5 hr.sup.-1 H.sub.2/Oil
ratio: 980 H.sub.2/Oil ratio: Nm.sup.3/kl-oil 980
Nm.sup.3/kl-oil
[0098] Reduction in degree of activity=100.times.(activity with 5
wt % accumulated metal-activity with 30 wt % accumulated
metal)/activity with 5 wt % accumulated metal
[0099] The present invention provides a process of hydrocracking
heavy oil with a catalyst in petroleum refining, which enables
hydrocracking to give light hydrocarbon oil with less formation of
coke, while asphaltene contained in the heavy oil is selectively
adsorbed and cracked and impurities including heavy metals such as
nickel and vanadium are selectively removed.
[0100] The catalyst of the invention can be used as a catalyst
which has less reduction in activity and high tolerance to
accumulation of heavy metals such as nickel and vanadium contained
in heavy oils and is charged in a guard reactor arranged in an
upstream of a desulfurization process, for the purpose of removing
heavy metals in heavy oils.
* * * * *