U.S. patent application number 13/911842 was filed with the patent office on 2013-12-19 for bulk catalyst composition comprising bulk metal oxide particles.
This patent application is currently assigned to ALBEMARLE NETHERLANDS B.V.. The applicant listed for this patent is Sona Eijsbouts-Spickova, Paul Joseph Maria Lebens, Robertus Gerardus Leliveld, Sabato Miseo, Bob Gerardus Oogjen, Frans Lodewijk Plantenga, Stuart Leon Soled, Henk Jan Tromp. Invention is credited to Sona Eijsbouts-Spickova, Paul Joseph Maria Lebens, Robertus Gerardus Leliveld, Sabato Miseo, Bob Gerardus Oogjen, Frans Lodewijk Plantenga, Stuart Leon Soled, Henk Jan Tromp.
Application Number | 20130337996 13/911842 |
Document ID | / |
Family ID | 40386529 |
Filed Date | 2013-12-19 |
United States Patent
Application |
20130337996 |
Kind Code |
A1 |
Eijsbouts-Spickova; Sona ;
et al. |
December 19, 2013 |
BULK CATALYST COMPOSITION COMPRISING BULK METAL OXIDE PARTICLES
Abstract
The invention relates to a process for preparing bulk metal
oxide particles comprising the steps of combining in a reaction
mixture (i) dispersible nanoparticles having a dimension of less
than about 1 .mu.m upon being dispersed in a liquid, (ii) at least
one Group VIII non-noble metal compound, (iii) at least one Group
VIB metal compound, and (iv) a protic liquid; and reacting the at
least one Group VIII non-noble metal compound and the at least one
Group VIB metal in the presence of the nanoparticles. It also
relates to bulk metal hydroprocessing catalysts obtainable by such
method.
Inventors: |
Eijsbouts-Spickova; Sona;
(Nieuwkujik, NL) ; Leliveld; Robertus Gerardus;
(Utrecht, NL) ; Lebens; Paul Joseph Maria;
(Woerden, NL) ; Plantenga; Frans Lodewijk;
(Hoevelaken, NL) ; Oogjen; Bob Gerardus; (Almere,
NL) ; Tromp; Henk Jan; (Utrecht, NL) ; Soled;
Stuart Leon; (Pittstown, NJ) ; Miseo; Sabato;
(Pittstown, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Eijsbouts-Spickova; Sona
Leliveld; Robertus Gerardus
Lebens; Paul Joseph Maria
Plantenga; Frans Lodewijk
Oogjen; Bob Gerardus
Tromp; Henk Jan
Soled; Stuart Leon
Miseo; Sabato |
Nieuwkujik
Utrecht
Woerden
Hoevelaken
Almere
Utrecht
Pittstown
Pittstown |
NJ
NJ |
NL
NL
NL
NL
NL
NL
US
US |
|
|
Assignee: |
ALBEMARLE NETHERLANDS B.V.
Amersfoort
NL
|
Family ID: |
40386529 |
Appl. No.: |
13/911842 |
Filed: |
June 6, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12743153 |
May 14, 2010 |
|
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|
PCT/US08/85536 |
Dec 4, 2008 |
|
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13911842 |
|
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61005248 |
Dec 4, 2007 |
|
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Current U.S.
Class: |
502/74 |
Current CPC
Class: |
B01J 37/03 20130101;
B01J 37/20 20130101; C10G 49/04 20130101; B01J 21/16 20130101; B01J
37/0009 20130101; B01J 23/888 20130101; B01J 23/85 20130101; B01J
23/8885 20130101; B01J 35/002 20130101 |
Class at
Publication: |
502/74 |
International
Class: |
B01J 23/888 20060101
B01J023/888 |
Claims
1. A process for preparing bulk metal oxide particles comprising
the steps of combining in a reaction mixture (i) dispersible
nanoparticles having a dimension of less than about 1 .mu.m upon
being dispersed in a liquid, (ii) at least one Group VIII non-noble
metal compound, (iii) at least one Group VIB metal compound, and
(iv) a protic liquid; and reacting the at least one Group VIII
non-noble metal compound and the at least one Group VIB metal in
the presence of the nanoparticles, wherein said nanoparticles are
different in composition from said at least one Group VIII
non-noble metal compound and said at least one Group VIB metal
compound.
2. The process according to claim 1, wherein the nanoparticles are
clay mineral particles.
3. The process according to claim 1 or claim 2, wherein at least
one Group VIII non-noble metal compound and at least two Group VIB
metal compounds are combined in the reaction mixture.
4. The process according to any one of claim 1 or 2, wherein the
reaction mixture further comprises a Group V metal compound.
5. The process according to any one of claim 1 or 2, wherein the
metal compounds are at least partly in the solid state during the
process.
6. The process according to any one of claims 1 or 2, wherein the
nanoparticles are added to the reaction mixture after the metal
compounds.
7. The process according to claim 5, wherein the reaction mixture
is prepared by: a) preparing a first suspension of at least one
Group VIII non-noble metal compounds in a protic liquid; b)
preparing a second suspension of at least one Group VIB metal
compounds in a protic liquid, and c) combining the first and second
suspensions together, wherein either the first, second, or both
suspensions contain nanoparticles and wherein said nanoparticles
are different in composition from said at least one Group VIII
non-noble metal compound and said at least one Group VIB metal
compound.
8. The process according to claim 7, wherein the at least one Group
VIII non-noble metal compound comprises nickel (hydroxy) carbonate
precipitated in the presence of nanoparticles.
9. The process according to any one of claim 1 or 2, wherein the
nanoparticles comprise platelets having a thickness of 0.1 to 1.5
nm, an aspect ratio of 100 to 1500 and a surface area greater than
250 m.sup.2/g.
10. The process according to any one of claims 1 or 2, wherein the
nanoparticles are clay mineral particles selected from the group
consisting of synthetic clays of the smectite family, layered
silicic acids, kaolinite, laponite, halloysite and mixtures
thereof.
11. The process according to claim 10, wherein the clay mineral
nanoparticles consist essentially of laponite.
12. A bulk catalyst composition comprising bulk metal oxide,
sulfide, or a combination of oxide and sulfide particles having (i)
dispersible nanoparticles having a dimension of less than about 1
.mu.m upon dispersion in a liquid, (ii) at least one Group VIII
non-noble metal compound, and (iii) at least one Group VIB metal
compound, obtainable by the process according to any one of claims
1 to 11 wherein said nanoparticles are different in composition
from said at least one Group VIII non-noble metal compound and said
at least one Group VIB metal compound.
13. A bulk catalyst composition comprising bulk metal oxide,
sulfide, or a combination of oxide and sulfide particles comprising
(i) dispersible nanoparticles having a dimension of less than about
1 .mu.m upon dispersion in a liquid, (ii) at least one Group VIII
non-noble metal compound, and (iii) at least one Group VIB metal
compound, wherein the bulk metal oxide particles are prepared by
combining in a reaction mixture the nanoparticles, at least one
Group VIII non-noble metal compound, at least one Group VIB metal
compound, and a protic and reacting the at least one Group VIII
non-noble metal compound and the at least one Group VIB metal
compound in the presence of the nanoparticles, wherein said
nanoparticles are different in composition from said at least one
Group VIII non-noble metal compound and said at least one Group VIB
metal compound.
14. A bulk catalyst composition comprising bulk metal oxide and/or
sulfide particles, wherein the bulk metal particles comprise: from
about 50 wt. % to about 99.5 wt. % (calculated as metal oxide
weight relative to the total weight of the bulk metal oxide and/or
sulfide catalyst particles) of at least one Group VIII non-noble
metal and at least one Group VIB metal, the metals being the form
of oxides and/or sulfides, and from about 0.5 wt. % to about 15 wt.
% (relative to the total weight of the bulk metal particles) of
nanoparticles having a dimension of less than 1 .mu.m upon
dispersion in a liquid, wherein said nanoparticles are different in
composition from said at least one Group VIII non-noble metal
compound and said at least one Group VIB metal compound.
15. The bulk catalyst composition of claim 14, wherein the at least
one Group VIII non-noble metal is cobalt and/or nickel.
16. The bulk catalyst composition of claim 15, wherein nickel
and/or cobalt represent at least about 90 wt. %, calculated as
oxide, of the total of the Group VIII non-noble metals.
17. The bulk catalyst composition according to any of claims 14 to
16, wherein the at least one Group VIB metal is molybdenum and/or
tungsten.
18. The bulk catalyst composition according to any of claims 14 to
17, wherein the only Group VIII non-noble metal is nickel and the
only Group VIB metal is tungsten.
19. The bulk catalyst composition of claim 14, wherein the bulk
metal oxide and/or sulfide particles comprise molybdenum and
tungsten, and wherein the molar ratio of molybdenum:tungsten is in
the range from about 3:1 to about 1:6.
20. The bulk catalyst composition according to any of claims 14 to
18, characterized by a molar ratio of Group VIB metals to Group
VIII non-noble metals in the range from about 3:1 to about 1:3.
21. The bulk catalyst composition according to any of claims 14 to
20, further comprising a Group V metal.
22. The bulk catalyst composition of claim 21, wherein the molar
ratio of Group V metals to Group VIB metals is between about 0.01
and about 5.
Description
TECHNICAL BACKGROUND OF THE INVENTION
[0001] The invention relates to a bulk catalyst composition, in
particular a hydroprocessing bulk catalyst composition, and a
process for its preparation of, wherein the bulk catalyst
composition comprises bulk metal oxide particles having at least
one Group VIII non-noble metal, at least one Group VIB metal, and
dispersible nanoparticles.
DESCRIPTION OF THE PRIOR ART
[0002] The hydroprocessing of hydrocarbon feedstocks generally
encompasses all processes in which a hydrocarbon feedstock is
reacted with hydrogen in the presence of a catalyst and under
hydroprocessing conditions, typically, at elevated temperature and
elevated pressure. The term hydroprocessing includes, but is not
limited to, processes such as hydrogenation, hydrodesulfurization,
hydrodenitrogenation, hydrodemetallization, hydrodearomatization,
hydroisomerization, hydrodewaxing, hydrocracking and mild
hydrocracking.
[0003] In general, conventional hydroprocessing catalysts are
composed of a carrier (or support) with a Group VIB metal component
and a Group VIII non-noble metal component deposited thereon. Such
catalysts may be prepared by impregnating a carrier with aqueous
solutions of compounds of the desired metals, followed by one or
more drying and/or calcination steps.
[0004] Alternative techniques for, the preparation of the
"supported" catalysts are described in U.S. Pat. No.
4,113,605--where inter alis nickel carbonate is reacted with
MoO.sub.3 to form crystalline nickel molybdate, which is
subsequently mixed and extruded with alumina--and in German Patent
No. DE 3029266, where nickel carbonate is mixed with WO.sub.3 and
the resulting composition is mixed with alumina impregnated with
compounds such as nickel nitrate and ammonium tungstate.
[0005] A significant amount of attention has recently been directed
to the provision of catalysts, which can be applied without a
carrier, generally referred to as bulk catalysts. WO 99/03578
describes a method for the preparation of bulk hydroprocessing
catalysts compositions comprising bulk metal oxide particles having
one Group VIII non-noble metal and two Group VIB metals by reacting
and co-precipitating nickel, molybdenum, and tungsten compounds in
the absence of sulfides.
[0006] WO 00/41810 describes a method for the preparation of a
hydroprocessing catalyst comprising bulk metal oxide particles
wherein one or more Group VIII non-noble metal and two or more
Group VIB metals are reacted in a protic liquid, wherein the metal
compounds are at least partly in the solute state (i.e., dissolved)
during the reaction. The prior art also discloses producing the
hydroprocessing catalyst in a convenient form for use in a
hydroprocessing process by shaping, for example by extrusion, and
by compositing the obtained bulk metal oxide particles with small
quantities of further materials, for example binder material, to
facilitate shaping and to provide mechanical strength to a shaped
catalyst.
[0007] Although the bulk catalyst compositions described in the
prior art have an excellent hydroprocessing activity, there exists
a continuous need in the art to develop novel bulk catalyst
compositions with further improved hydroprocessing activity, in
particular, in hydrodesulfurisation (HDS), as well as
hydrodenitrogenation (HDN), and hydrogenation of particular target
hydrocarbon feedstocks, such as diesel and vacuum gas oil
(VGO).
[0008] For instance, WO 00/41810 describes bulk catalysts having
bulk metal oxide particles comprising at least one Group VIII metal
and at least 2 Group VIB metals with varying ratios of Group VIII
to Group VIB metals. The examples describe that increasing
hydrodesulfurisation (HDS) activity is obtained at increasing molar
ratios of Group VIII metal over Group VIB metals. This document
indicates in particular that, for bulk metal catalysts having one
Group VIII metal and one Group VIB metal, it is very difficult to
obtain a suitably active catalyst at a Group VIII to Group VIB
metal molar ratio below 1.25. Furthermore, at metal molar ratios
below about 1.1 to 1, a completely different crystal structure is
obtained that was not active at all. From a theoretical point of
view, it is believed that such large amounts of Group VIII metal,
although advantageous or even necessary in the process of the
preparation of the catalyst, may not be necessary, or not fully
necessary, in the active sulfided bulk catalyst employed in the
hydrotreatment of a hydrocarbon feedstock. While high Group VIII to
Group VIB metal molar ratios appear to be useful during catalyst
synthesis, excessive amounts of Group VIII metals seem to only add
unnecessary weight and to reduce the activity per unit weight of
the bulk catalyst composition once the bulk metal oxide particles
are sulfided. Thus, there is a desire to find higher activity
catalyst, in particular for bulk catalysts comprising at least one
Group VIII and at least one Group VIB metal that can be produced
with low Group VIII to Group VIB metal molar ratios.
SUMMARY OF THE INVENTION
[0009] Accordingly, a bulk catalyst composition is provided
comprising bulk metal oxide particles having (i) dispersible
nanoparticles having a dimension of less than about 1 .mu.m upon
being dispersed in a liquid, (ii) at least one Group VIII non-noble
metal compound, and (iii) at least one Group VIB metal compound; as
well as a process for preparing such bulk metal oxide particles
comprising the steps of combining in a reaction mixture (i)
dispersible nanoparticles having a dimension of less than about 1
.mu.m upon being dispersed in a liquid, (ii) at least one Group
VIII non-noble metal compound, (iii) at least one Group VIB metal
compound, and (iv) a protic liquid; and reacting the at least one
Group VIII non-noble metal compound and the at least one Group VIB
metal compound.
[0010] The process preferably comprises: (a) preparing a first
suspension of at least one Group VIII non-noble metal compounds in
a protic (b) preparing a second suspension of at least one Group
VIB metal compounds in a protic liquid and (c) adding the first and
second suspensions together, wherein at least one of the first or
second suspensions comprises dispersible nanoparticles having a
dimension of less than about 1 .mu.m upon being dispersed in a
liquid. More preferably, at least a portion of the nanoparticles is
included in the first suspension of the Group VIII non-noble metal
compound. Most preferably, at least a portion of the nanoparticles
is included in a first suspension that comprises at least one of
nickel carbonate, nickel hydroxy-carbonate, cobalt carbonate and
cobalt hydroxy-carbonate.
[0011] In one embodiment, the Group VIB or VIII metal compound is
prepared by precipitation in the presence of the nanoparticles.
Preferably, nickel (hydroxy-) carbonate and cobalt (hydroxy-)
carbonate are prepared by precipitation in the presence of
nanoparticles, preferably of synthetic clay mineral.
[0012] This process can also be used to make bulk metal oxide
particles comprising at least one Group VIII non-noble metal
compound and at least two Group VIB metal compounds.
[0013] In another embodiment of the process according to the
invention, the reaction mixture further comprises a Group V metal
compound, preferably a niobium compound. The Group V metal has been
found to promote, even when present in relatively low amounts, the
formation of an active catalyst especially in critical composition
ranges, for example at low. Group VIII to Group VIB metal molar
ratio. The term "active catalyst" means a catalyst having a high
HDS and/or HDN activity.
[0014] This invention is also directed to a bulk catalyst
composition comprising bulk metal oxide catalyst particles
comprising at least one Group VIII non-noble metal, at least one
Group VIB metal and dispersible nanoparticles having a dimension of
less than about 1 .mu.m upon being dispersed in a liquid,
obtainable by the process according to the invention. Further, in
accordance with another aspect of the invention there is provided a
bulk catalyst composition comprising bulk metal oxide catalyst
particles which comprise at least one Group VIII non-noble metal
and at least one Group VIB metal, said Group VIII and Group VIB
metals representing from about 50 wt. % to about 99.5 wt. %,
calculated as oxides, of the total weight of the bulk catalyst
composition, the metals being present in the bulk catalyst
composition in their oxidic state and/or their sulfidic state, and
from about 0.5 wt. % to about 15 wt. % (based of the total weight
of the bulk metal oxide catalyst particles) of nanoparticles. The
invention further relates to a sulfided bulk catalyst obtainable by
sulfiding the above described bulk catalyst composition comprising
bulk metal oxide catalyst particles.
[0015] Within the bulk catalyst composition it is preferred that
the bulk metal oxide catalyst particles preferably comprise: i)
from about 50 wt. % to about 99.5 wt. %, more preferably from about
70 wt. % to about 99 wt. %, and most preferably from about 85 wt. %
to about 95 wt. % of said Group VIII non-noble metals and Group VIB
metals, calculated as oxides based of the total weight of the bulk
catalyst composition, the metals being present in their oxidic
and/or sulfidic states; and, ii) from about 0.5 wt. % to about 15
wt. %, preferably from about 1 to about 10 wt. %, more preferably
from about 1 to about 5 wt. % and even more preferably from about 2
to about 4 wt. % (based of the total weight of the bulk metal oxide
catalyst particles) of nanoparticles. Considering that particles
always have a particle size distribution, it is preferred that at
least about 50 wt. %, preferably at least about 70 wt % of the
total amount of added nanoparticles have a lateral dimension of
less than about 1 .mu.m.
[0016] In accordance with another aspect of the invention there is
provided a process for the hydroprocessing of a hydrocarbon
feedstock wherein the feedstock is contacted under hydroprocessing
conditions with the aforementioned bulk catalyst composition. The
bulk catalyst composition according to this invention can be used
in virtually all hydroprocessing processes to treat a plurality of
feedstocks under wide-ranging reaction conditions, including but
not limited to pre-treating a feedstock prior to its being
hydrocracked. Generally, these reaction conditions comprise a
temperature in the range from about 200.degree. to about
450.degree. C., hydrogen pressures in the range from about 5 to
about 300 Bar, liquid hourly space velocities (LHSV) in the range
from about 0.5 to about 10 h.sup.-1 and H.sub.2/oil ratios in the
range from about 50 to about 2000 Nl/l. However, it is preferred to
employ the catalyst of the present invention in the hydroprocessing
of, and more particularly, the hydrodesulfurisation (HDS),
hydrodenitrogenation (HDN) and hydrodearomatization (HDA) of
feedstocks comprising a diesel oil or a vacuum gas oil under
conditions at least comprising liquid hourly space velocities
(LHSV) in the range from about 0.5 to about 10 h.sup.-1 and
H.sub.2/oil ratios in the range from about 50 to about 2000 Nl/l.
The bulk catalyst composition has been found to show improved
hydrodesulfurisation activity under conditions wherein the
feedstock has a low nitrogen level, in particular in VGO. One
preferred embodiment of the invention is as a catalyst for the
pre-treatment of a feedstock prior to it being hydrocracked.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is an X-ray diffraction pattern of a bulk catalyst
composition according to the present invention.
[0018] FIG. 2 shows a comparison between the X-ray diffraction
pattern of a bulk catalyst composition according to the present
invention and a comparative composition.
DETAILED DESCRIPTION OF THE INVENTION
[0019] It has been found that a bulk catalyst composition
comprising bulk metal particles prepared by combining and reacting,
in the presence of dispersible nanoparticles having a dimension of
less than 1 .mu.m in its dispersed state, at least one Group VIII
non-noble metal compound with at least one Group VIB metal compound
in a reaction mixture with a protic liquid have many advantages
over corresponding catalysts comprising bulk metal particles
prepared without the nanoparticles. For example, it was found that
bulk metal catalysts prepared with nanoparticles having a dimension
of less than 1 .mu.m in their dispersed state provide catalysts
having a significantly higher hydroprocessing activity than the
same catalyst prepared without such nanoparticles in the reaction
mixture. Further, the desired highly active metal oxide bulk
particle structure is formed in a significantly shorter time than
in the absence of the nanoparticles, even at low Group VIII to
Group VIB metal molar ratios.
[0020] The various embodiments relating to these findings are
described below in further detail.
Compounds and Materials
Nanoparticles
[0021] Since the mixed metal oxide/sulfide particles formed during
the catalyst preparation process can also be nanoparticles, the
term nanoparticles as used herein does not refer to metal oxide
nanoparticles that may form during the catalyst synthesis process,
but to other nanoparticles deliberately added to the reaction
mixture used to synthesize the mixed metal oxide particles. In a
preferred embodiment, the nanoparticles are clay mineral
nanoparticles, preferably synthetic clay mineral nanoparticles,
having a dimension of less than about 1 .mu.m. More preferably, the
nanoparticles have a largest dimension, in three coordinate space,
of less than about 1 .mu.m, preferably less than 500 nm, more
preferably less than 250 nm, and even more preferably less than 100
nm. The nanoparticles preferably have a smallest dimension, in
three coordinate space, of less than 25 nm, preferably less than 10
nm, even more preferably less than 5 nm, and even more preferably
less than 1 nm. A nanoparticle's dimensions can be determined by
TEM, light scattering methods, or equivalent methods known in the
art, as described hereafter. Conveniently, at least 50 wt. %, such
as at least 70 wt. % of the nanoparticles have a largest dimension
of less than about 1 .mu.m.
[0022] In addition to definitions described above, the term
"nanoparticles" as used herein encompasses particles of any shape
having appropriate dimensions and, as such, include spherical,
polyhedral, nanofiber and disc-like nanoparticles.
[0023] Preferably the nanoparticles used in the present invention
are clay minerals, more preferably synthetic clay minerals, that
can provide disc-like nanoparticles when dispersed in the protic
liquid of the invention and which thus present a flat or quasi-flat
surface during the reaction of the metal compounds which form the
bulk metal oxide particles. More preferably clay minerals, which
can provide disc-like particles having a surface area greater than
about 250 m.sup.2/g, most preferably greater than about 350
m.sup.2/g are desirable. Such clay minerals include synthetic 2:1
type clays and natural and synthetic layered silicic acids. The
nanoparticles are preferably a clay mineral selected from the group
consisting of synthetic clays of the smectite family, layered
silicic acids, kaolinite, laponite, halloysite and mixtures
thereof.
[0024] Synthetic 2:1 types clays suitable for inclusion in this
invention--such as fluorohectorite, laponite and
fluoromicas--include those of the smectite family with the crystal
structure consisting of nanometer thick sheets of aluminium (Al)
octahedra sandwiched between two silicon (Si) tetrahedron sheets.
These three-sheet layers are stacked with a van de Waals gap
between the layers. Isomorphic substitution of Al with magnesium
(Mg), iron (Fe) or lithium (Li) in the octahedra sheets and/or Si
with Al in the tetrahedron sheets gives each three sheet layer an
overall negative charge which is counterbalanced by exchangeable
metal cations in the interlayer space such as sodium (Na), calcium
(Ca), Mg, Fe and Li.
[0025] Synthetic layered silicic acids suitable for inclusion in
this invention--such as kanemite, makatite, octasilicate, magadite
and kenyaite--are clays that consist mainly of silicon tetrahedron
sheets with different layer thickness. They exhibit similar
intercalation chemistry to the aforementioned smectites;
furthermore, as they possess high purity and structural properties
that are complimentary to these smectite clays, this facilitates
their use in combination with said smectites.
[0026] The intercalation chemistry of both the synthetic smectite
clays and the synthetic layered silicic acids allows them to be
chemically modified to be compatible with the further metal
compounds of the bulk catalyst composition.
[0027] Synthetic 2:1 type clays and layered silicic acids are
typically available commercially as powders. These powder minerals
and other clays are preferably exfoliated and/or delaminated into
disc-like nanoparticles before use in the process according to the
invention. Preferably this is carried out by dispersion of the
powders in a liquid, preferably water, for a sufficiently long
period of time to exfoliate and/or delaminate into disc-like
nanoparticles. Without wishing to be bound by theory, the formation
of disc-like nanoparticles from such powders is believed to occur
by the following process: i) a wetting of the powders to form
aggregated particle stacks, each stack being analogous to a column
of coins with each coin being a layer of the clay structure; ii)
dispersion of said aggregated stacks into individual particle
stacks ("secondary particles"); iii) hydration of intercalated
sodium ions within the stacks; and iv) separation into individual
particles ("primary particles").
[0028] It is to be noted that both the non-aggregated individual
stacks (secondary particles) and the primary particles can be
nanoparticles within the meaning of this invention. The primary
particles of these disc-shaped clay minerals are generally
characterized by a thickness ranging from about 0.1 and about 1.5
nm, a lateral dimension of less than about 100 nm, an aspect ratio
of about 100 to about 1500 and surface areas greater than about 250
m.sup.2/g. However, it is desirable in the present invention to use
clays which can be provided as--or delaminated/exfoliated
into--primary and secondary particles which are characterized by a
surface area ranging from about 350 to about 1000 m.sup.2/g, and
wherein the (constituent) primary particles have a thickness of
about 1 nm, and a lateral dimension of less than about 100 nm.
[0029] As such, it is preferred in the present invention that the
nanoparticles comprise a synthetic clay of the smectite family.
More preferably, the nanoparticles comprise greater than about 70
wt. %, preferably greater than about 90 wt. %, laponite, based on
the total weight of the nanoparticles. Most preferably, the
nanoparticles consist essentially of laponite.
[0030] The clay mineral nanoparticles may also be prepared as
organoclays. Organoclays are manufactured by modifying clay with
quaternary amines, a type of surfactant that contains a nitrogen
ion. The nitrogen end of the quaternary amine, the hydrophilic end,
is positively charged, and can be ion-exchanged for sodium or
calcium. The amines used typically are of the long chain type with
from about 12 to about 18 carbon atoms. If a, certain minimum
percentage, typically about 30% t, of the clay surface is coated
with these amines, the clay becomes hydrophobic. With certain
amines, the clay can be made organophilic.
Other Compounds and Materials
[0031] The process for the preparation of bulk catalysts according
to the invention combines in a reaction mixture with a protic
liquid, metal compounds and nanoparticles, and reacts the metals in
the presence of the nanoparticles. The protic liquid can be any
protic liquid which does not interfere with the reactions of the
metal compounds or the dispersion of the nanoparticles. Examples
include water, carboxylic acids, and alcohols such as methanol,
ethanol or mixtures thereof. Preferred protic liquids are mixtures
of water and other protic liquids, such as mixtures of an alcohol
and water, and a more preferded protic liquid is water alone.
[0032] It will be evident that different protic liquids can be
applied simultaneously in the process of this invention. For
instance, it is possible to add a suspension of a metal compound in
ethanol to an aqueous solution of another metal compound. In some
cases, a metal compound can be used which dissolves in its own
water of crystallization. The water of crystallization serves as
protic liquid in this case.
[0033] At least one Group VIII non-noble metal compound and at
least one Group VIB metal compound are used in the process of the
invention. Suitable Group VIB metals include chromium, molybdenum,
tungsten, or mixtures thereof, with a combination of molybdenum and
tungsten being most preferred. Suitable Group VIII non-noble metals
include iron, cobalt, nickel, or mixtures thereof, preferably
cobalt and/or nickel. Preferably, a combination of metal compounds
comprising either i) nickel and tungsten; ii) nickel and
molybdenum; iii) nickel, molybdenum, and tungsten; iv) cobalt and
tungsten; v) cobalt and molybdenum; vi) cobalt, molybdenum, and
tungsten; or vii) nickel, cobalt, molybdenum and tungsten is used
in the process of the invention.
[0034] In a preferred embodiment, nickel and cobalt make up at
least about 50 wt. %, more preferably at least about 70 wt. %,
still more preferably at least about 90 wt. % of the total of Group
VIII non-noble metal compounds, calculated as oxides. It is even
more preferred for the Group VIII non-noble metal compound to
consist essentially of nickel and/or cobalt.
[0035] In another preferred embodiment, molybdenum and tungsten
represent at least about 50 wt. %, more preferably at least about
70 wt. %, still more preferably at least about 90 wt. % of the
total of Group VIB metal compounds, calculated as trioxides. It is
even more preferred for the Group VIB metal compound to consist
essentially of a mixture of molybdenum and tungsten.
[0036] The molar ratio of Group VIB metal to Group VIII non-noble
metals applied in the process of the invention generally ranges
from about 10:1 to about 1:10 and preferably ranges from about 3:1
to about 1:3. The molar ratio of the different Group VIB metals to
one another generally is not critical. The same holds when more
than one Group VIII non-noble metal is applied. When molybdenum and
tungsten are used as Group VIB metals, the molybdenum:tungsten
molar ratio preferably lies in the range of about 9:1 to about
1:19, more preferably about 3:1 to about 1:9, most preferably about
3:1 to about 1:6.
[0037] In another embodiment, the bulk catalyst according to the
invention comprises a Group V metal, preferably niobium.
Preferably, they Group V metal is present in an amount ranging from
about 0.1 to about 10 mole % (relative to the total of the Group
VIB metals), more preferably from about 0.1 to about 9 mole %, more
preferably from about 0.1 to about 8, even more preferably from
about 0.1 to about 7, and most preferably from about 0.1 to about 5
mole %. The Group V metal has been found to promote, even when
present in relatively low amounts, the formation of an active
catalyst especially in critical composition ranges, for example at
low Group VIII to Group VIB metal molar ratio. The presence of a
Group V metal, preferably niobium, is particularly preferred where
the molar ratio of Group VIII metal over Group VIB metal is below
about 1.5:1, even more preferred when it is below about 1.4:1,
about 1.3:1, or even below about 1.2:1. Particularly preferred
catalysts according to invention comprise Group VIII metals Co, Ni,
or a mixture of Co and Ni, and Group VIB metals W, Mo, or a mixture
of W and Mo, preferably only Ni and W, in a metal molar ratio below
about 1.2:1, and further comprise between about 0.1 and about 5
mole % (relative to the total of the Group VIB metals, wherein all
metals are expressed as oxides) of a Group V metal, preferably
niobium, and about 0.5 to about 5 wt % (relative to the total
weight of the bulk metal oxide particle) of a synthetic nanoclay,
wherein the Group VIII, Group VIB and Group V metals form at least
about 95 wt % (based on oxides) of the total of the metal compounds
in the bulk catalyst particles and at least about 50 wt %,
preferably at least about 70 wt % relative to the total weight of
the bulk catalyst composition.
[0038] If the protic liquid is water, the solubility of the Group
VIII non-noble metal compounds and Group VIB metal compounds which
are at least partly in the solid state during the process of the
invention generally is less than about 0.05 mol/100 ml water at
18.degree. C. This may be contrasted with the high solubility of
the selected compounds of, for example, GB 1 282 950.
[0039] If the protic liquid is water, suitable Group VIII non-noble
metal compounds which are at least partly in the solid state during
the process of the invention comprise Group VIII non-noble metal
compounds with a low solubility in water such as citrates,
oxalates, carbonates, hydroxy-carbonates, hydroxides, phosphates,
phosphides, sulfides, aluminates, molybdates, tungstates, oxides or
mixtures thereof. Preferably, Group VIII non-noble metal compounds
which are at least partly in the solid state during the process of
the invention comprise, and more preferably consist essentially of,
oxalates, carbonates, hydroxy-carbonates, hydroxides, phosphates,
molybdates, tungstates, oxides, or mixtures thereof, with
hydroxy-carbonates and carbonates being most preferred. Generally,
the molar ratio between the hydroxy groups and the carbonate groups
in the hydroxy-carbonate lies in the range, from 0 to about 4,
preferably from 0 to about 2, more preferably from 0 to about 1 and
most preferably from about 0.1 to about 0.8.
[0040] If the protic liquid is water, suitable nickel and cobalt
compounds which are at least partly in the solid state during the
process of the invention comprise slightly soluble nickel or cobalt
or mixed nickel-cobalt compounds such as oxalates, citrates,
aluminates, carbonates, hydroxy-carbonates, hydroxides, molybdates,
phosphates, phosphides, sulfides, tungstates, oxides, or mixtures
thereof. Preferably, the nickel or cobalt compound comprises, and
more preferably consists essentially, of oxalates, citrates,
carbonates, hydroxy-carbonates, hydroxides, molybdates, phosphates,
tungstates, oxides, or mixtures thereof, with nickel and/or cobalt
hydroxy-carbonate, nickel and/or cobalt hydroxide, nickel and/or
cobalt carbonate, or mixtures thereof being most preferred.
Generally, the molar ratio between the hydroxy groups and the
carbonate groups in the nickel or cobalt or nickel-cobalt
hydroxy-carbonate lies in the range of 0 to about 4, preferably 0
to about 2, more preferably 0 to about 1 and most preferably about
0.1 to about 0.8. Suitable iron compounds which are at least partly
in the solid state are iron(II) citrate, iron carbonate,
hydroxy-carbonate, hydroxide, phosphate, phosphide, sulfide, oxide,
or mixtures thereof, with iron(II) citrate, iron carbonate,
hydroxy-carbonate, hydroxide, phosphate, oxide, or mixtures thereof
being preferred.
[0041] If the protic liquid is water, suitable low water-solubility
Group VIB metal compounds which are thus at least partly in the
solid state during contacting include di- and trioxides, carbides,
nitrides, aluminium salts, acids, sulfides or mixtures thereof. Of
this group, it is preferred that the Group VIB metal compounds
consist essentially of, di- and trioxides, acids or mixtures
thereof.
[0042] Suitable molybdenum compounds which are at least partly in
the solid state during the process of the invention comprise
water-insoluble molybdenum compounds such as molybdenum di- and
trioxide, molybdenum sulfide, molybdenum carbide, molybdenum
nitride, aluminium molybdate, molybdic acids (e.g.
H.sub.2MoO.sub.4), ammonium phosphomolybdate, or mixtures thereof,
with molybdic acid and molybdenum di- and trioxide being
preferred.
[0043] Finally, suitable tungsten compounds which are at least
partly in the solid state during the process of the invention
comprise water-insoluble tungsten compounds, such as tungsten di-
and trioxide, tungsten sulfide (WS.sub.2 and WS.sub.3), tungsten
carbide; ortho-tungstic acid (H.sub.2WO.sub.4*H.sub.2O), tungsten
nitride, aluminium tungstate (also meta- or polytungstate),
ammonium phosphotungstate, or mixtures thereof, with ortho-tungstic
acid and tungsten di- and trioxide being preferred.
[0044] All the above compounds generally are commercially available
or can be prepared by, for example, precipitation. In particular
nickel hydroxy-carbonate can be prepared from a nickel chloride,
sulfate, or nitrate solution by adding an appropriate amount of
sodium carbonate. It is generally known to the skilled person to
choose the precipitation conditions in such a way as to obtain the
desired morphology and texture of the resultant precipitate, and
more particularly to control the particle size (surface area) of
the precipitate.
[0045] In general, metal compounds, which mainly contain C, O
and/or H in addition to the metal, are preferred because they are
less detrimental to the environment. Group VIII non-noble metal
carbonates and hydroxy-carbonate are preferred metal compounds to
be added at least partly in the solid state because when carbonate
or hydroxy-carbonate is applied, CO.sub.2 evolves and positively
influences the pH of the reaction mixture. Further, because the
carbonate is transformed into CO.sub.2 and does not end up in that
waste water, it is possible to recycle the waste water.
Consequently, no washing step is necessary to remove undesired
anions from the resulting bulk metal oxide particles.
[0046] Preferred Group VIII non-noble metal compounds to be added
in the solute state comprise water-soluble Group VIII non-noble
metal salts such as nitrates, sulfates, acetates, chlorides,
formates, hypophosphites and mixtures thereof. Examples include
water-soluble nickel and/or cobalt compounds, e.g., water-soluble
nickel and/or cobalt salts such as nitrates, sulfates, acetates,
chlorides, formates, or mixtures thereof of nickel and/or cobalt as
well as nickel hypophosphite. Suitable iron compounds to be added
in the solute state comprise iron acetate, chloride, formate,
nitrate, sulfate, or mixtures thereof.
[0047] Suitable Group VIB metal compounds to be added in the solute
state include water-soluble Group VIB metal salts such as normal
ammonium or alkali metal monomolybdates and tungstates as well as
water-soluble isopoly-compounds of molybdenum and tungsten, such as
metatungstic acid, or water-soluble heteropoly compounds of
molybdenum or tungsten further comprising, e.g., P, Si, Ni, or Co
or combinations thereof. Suitable water-soluble isopoly- and
heteropoly compounds are described in Molybdenum Chemicals,
Chemical data series, Bulletin Cdb-14, February 1969 and in
Molybdenum Chemicals, Chemical data series, Bulletin
Cdb-12a-revised, November 1969. Suitable water-soluble chromium
compounds include normal chromates, isopolychromatcs and ammonium
chromium sulfate.
[0048] Preferred combinations of metal compounds are a Group VIII
non-noble metal hydroxy-carbonate and/or carbonate, such as nickel
or cobalt hydroxy-carbonate and/or carbonate, with a Group VIB
metal oxide and/or a Group VIB acid, such as the combination of
tungstic acid and molybdenum oxide, or the combination of
molybdenum trioxide and tungsten trioxide, or a Group VIII
hydroxy-carbonate and/or carbonate, such as nickel or cobalt
hydroxy carbonate and/or carbonate, with Group VIB metal salts,
such as ammonium dimolybdate, ammonium heptamolybdate, and ammonium
metatungstate. It is considered that the skilled person would be
able to select further suitable combinations of metal
compounds.
Preparation of the Catalyst of the Invention
(A) Preparation of Bulk Metal Oxide Particles
[0049] An aspect of the present invention is directed to a process
for preparing a bulk catalyst composition comprising bulk metal
oxide catalyst particles comprising at least one Group VIII
non-noble metal and at least one Group VIB metal, which process
comprises combining and reacting at least one Group VIII non-noble
metal compound with at least one Group VIB metal compound in a
reaction mixture with a protic liquid: wherein the reaction occurs
in the presence of dispersible nanoparticles, preferably
nanoparticles of clay mineral, the nanoparticles being
characterized by having a dimension of less than 1 .mu.m when in
its dispersed state.
[0050] Although it is possible for the process of this invention to
be performed by combination and reaction of all metal components
being in the solution state--as described in the disclosure of
WO99/03578 which is herein incorporated by reference--it is
preferred that at least one of the metal compounds remains at least
partly in the solid state during the entire process. The term "at
least partly in the solid state" as used herein means that at least
part of the metal compound is present as a solid metal compound
and, optionally, another part of the metal compound is present as a
solution of this metal compound in the protic liquid. A typical
example of this is a suspension of a metal compound in a protic
liquid in which the metal is at least partly present as a solid,
and optionally partly dissolved in the protic liquid. This
aforementioned "entire process" comprises combining and reacting
the metal compounds. More particularly, it comprises adding the
metal compounds to each other and simultaneously and/or thereafter
reacting them.
[0051] Without wishing to be bound by theory, it is believed that
this reaction can even take place if all metal compounds are
virtually completely in the solid state; due to the presence of the
protic liquid a small fraction of the metal compounds can dissolve,
interact and consequently react. The protic liquid is responsible
for the transport of dissolved metal compounds and therefore the
presence of a protic liquid during the process of the present
invention is considered essential. The reaction time in this
process is relatively long, preferably at least about 4 hours.
However, due to the presence of nanoparticles the desired active
structure is formed in a significantly shorter time than in the
absence of the nanoparticles.
[0052] The embodiment of the invention wherein at least one metal
compound is at least partly in the solid state during the process
of the invention can take place in several ways. In this respect,
it is considered, for example, that processes wherein i) a metal
compound which is at least partly in solid state is combined with a
metal compound which is in the solute state; ii) one of the metal
compounds is added at least partly in the solid state and two metal
compounds are added in the solute state; and iii) two metal
compounds are added at least partly in the solid state to one metal
compound in the solute state, are within the scope of this
embodiment of the invention. With the term "in the solute state" is
implied that the whole amount of this metal compound is added as a
solution of this metal compound in the protic liquid. However, a
fourth (iv) and preferred alternative is that all metal compounds
to be combined in the process of the invention are applied at least
partly in the solid state; this preferred embodiment reduces and
ideally eliminates those anionic species (such as nitrate) and
cationic species (such as ammonium ions) which are required for
dissolution of the metal compounds in the protic liquid but which
are not incorporated into the resultant mixed metal reaction
product.
[0053] Within these alternatives all orders of addition of the
metal compounds are possible. For example, that metal compound
which is to remain at least partly in the solid state during the
entire process may be prepared first as a suspension of the metal
compound in a protic liquid to which added simultaneously or
sequentially, solution(s) and/or further suspension(s) comprising
dissolved and/or suspended further metal compound(s) in the protic
liquid. Equally, it is also possible to first prepare a solution of
a first metal component and then subsequently add the required
suspension(s) of the partly solid state metal compound(s) and
optionally further solution(s) either simultaneously or
sequentially. However it is preferred that all Group VIII non-noble
metal compounds are combined simultaneously and all Group VIB metal
compounds are combined simultaneously and the resulting two
mixtures are subsequently combined.
[0054] In all these cases; any suspension comprising a metal
compound can be prepared by suspending a solid metal compound in
the protic liquid. However, it is also possible to prepare the
suspension by precipitating a solid metal compound in a protic
liquid or (co)precipitating metal compounds where more than one
metal compound is to remain at least partly in the solid state
during the entire process. The further metal compounds may then be
added directly in solution, in slurry or per se to the suspension
resulting from this (co-) precipitation. Alternatively, the further
metal compounds may be added:
[0055] i) to a dry precipitate or co-precipitate after that
resulting precipitate has been treated by solid/liquid separation,
followed by the optional steps of drying and/or thermally
treating;
[0056] ii) to the precipitate of step i) above that has been
wetted; or
[0057] iii) to the precipitate of step i) or step ii) above that
has been reslurried in a protic liquid.
[0058] Regardless of whether the metal components are combined and
reacted in the solute state or combined and reacted with at least
one metal compound being at least partly in the solid state, the
reaction between the metal compounds must occur in the presence of
nanoparticles. The nanoparticles are preferably combined with the
metals as a suspension in an aqueous liquid. The nanoparticles may
be added to solutions or suspensions of individual metal compounds
prior to the combinations of said compounds with further metal
compounds or to the suspensions/solutions of already combined metal
compounds. It is preferred that the nanoparticles are admixed in a
suspension of the or a metal compound which is to remain at least
partly in the solid state during the entire process. Where that
suspension of the metal compound has been prepared, by
precipitation it is further preferred that the precipitation occurs
in the presence of the nanoparticles, preferably of synthetic clay
mineral nanoparticles.
[0059] In accordance with an embodiment of the invention, at least
a fraction and preferably all of the nanoparticles to be added are
included in a suspension of nickel and/or cobalt hydroxy-carbonate
or carbonate. More preferably these nickel and/or cobalt compounds
have been prepared by the aforementioned precipitation
reactions.
[0060] Without wishing to be bound by theory, the nanoparticles may
act as nuclei on which the metal compound, preferably nickel and/or
cobalt (hydroxyl-) carbonate, precipitates. The nanoparticles and
the nickel and/or cobalt compounds formed during the reaction are
thus intimately associated during formation of the bulk metal
particles.
[0061] Preferably, at least about 1 wt. %, even more preferably at
least about 10 wt. %, and still more preferably at least about 15
wt. % of a metal compound is added in the solid state during the
process of the invention, based on the total weight of all Group
VIB and Group VIII non-noble metal compounds, calculated as metal
oxides. When it is desired to obtain a high yield, that is a high
amount of the bulk metal oxide particles, the use of metal
compounds of which a high amount remains in the solid state during
the process of the invention may be the preferred method. In that
case, low amounts of metal compounds remain dissolved in the mother
liquid and the amount of metal compounds ending up in the waste
water during the subsequent solid-liquid separation is decreased.
Any loss of metal compounds can be avoided completely if the mother
liquid resulting from solid-liquid separation is recycled in the
process of the present invention. It is noted that it is a
particular advantage of the process of the present invention that,
compared to a catalyst preparation based on a co-precipitation
process--where anions and cations like ammonium can accumulate in
the mother liquor--the amount of waste water can be considerably
reduced.
[0062] In a preferred process the at least one, preferably all
metal compound remains at least partly in the solid state during
the process of the invention. Because in this embodiment the
reactivity is not very high, it is preferred that the compounds are
slightly soluble. Depending on the reactivity of the metal
compounds, preferably at least about 0.01 wt. %, more preferably at
least about 0.05 wt. %, and most preferably at least about 0.1 wt.
% of all metal compounds initially employed in the process of the
invention are in dissolved state in reaction conditions (based on
the total weight of all metal compounds, calculated as metal
oxides). In this way, proper contacting of the metal compounds is
ensured.
[0063] It has been found that the morphology and the texture of the
metal compound(s), which remain at least partly in the solid state
during the process of the invention, can be retained to some extent
during the process of the present invention. Consequently, by using
metal compound particles with a certain morphology and texture, the
morphology and the texture of the bulk metal oxide particles
contained in the final bulk catalyst composition can be controlled
at least to some extent. "Morphology and texture" in the context of
the present invention refer to pore volume, pore size distribution,
surface area, particle form and particle size. Morphologic
properties can be preserved by keeping at least a part of the raw
material at least partly in the solid state means, for example by
controlling the acidity (pH), for example by reducing the addition
of acid such that not all of the metal species dissolve (e.g., when
Ni carbonate, Mo oxide or tungstic acid is used).
[0064] Generally the surface area of the bulk metal oxide particles
is at least about 60%, preferably at least about 70%, and more
preferably at least about 80% of the surface area of the metal
compound which remains at least partly in the solid state during
the process of the invention. The surface area is expressed herein
as surface area per weight of this metal compound, calculated as
metal oxide. Further, the median pore diameter (determined by
nitrogen adsorption) of the oxidic bulk metal particles is at least
about 40% and preferably at least about 50% of the median pore
diameter of the metal compound which remains at least partly in the
solid state during the process of the invention. Furthermore, the
pore volume (determined by nitrogen adsorption) in the oxidic metal
particles generally is at least about 40% and preferably at least
about 50% of the pore volume of the metal compound which remains at
least partly in the solid state during the process of the
invention, with the pore volume being expressed herein as the
volume of pores per weight of this metal compound, calculated as
metal oxide.
[0065] The retention of the particle size generally is dependent on
the extent of mechanical damage undergone by the oxidic bulk metal
particles during processing, especially during steps such as mixing
or kneading. The particle diameter can be retained to a high extent
if these treatments are short and gentle. In this case, the median
particle diameter of the oxidic bulk metal particles generally is
at least about 80% and preferably at least about 90% of the median
particle diameter of the metal compound which remains at least
partly in the solid state during the process of the invention. The
particle size can also be affected by treatments such as
spray-drying, especially if further materials are present. It is
within the capability of the skilled person to select suitable
conditions in order to control the particle size distribution
during such treatments.
[0066] When a metal compound which is added at least partly in the
solid state and which has a large median particle diameter is
selected, it is thought that the other metal compounds will only
react with the outer layer of the large metal compound particle. In
this case, so-called "core-shell" structured bulk metal oxide
particles result (which will be described in greater detail
hereinbelow).
[0067] An appropriate morphology and texture of the metal
compound(s) can be achieved either by applying suitable preformed
metal compounds or by preparing these metal compounds by means of
the above-described precipitation or re-crystallization or any
other technique known by the skilled person under such conditions
that a suitable morphology and texture are obtained. A proper
selection of appropriate precipitation conditions can be made by
routine experimentation.
[0068] To obtain a final bulk catalyst composition with high
catalytic activity, it is preferred that the metal compound or
compounds which are at least partly in the solid state during the
process of the invention are porous metal compounds. It is desired
that the total pore volume and the pore size distribution of these
metal compounds are broadly similar to those of conventional
hydroprocessing catalysts. Conventional hydroprocessing catalysts
generally have a pore volume of about 0.05 to about 5 ml/g,
preferably of about 0.1 to about 4 ml/g, more preferably of about
0.1 to about 3 ml/g, and most preferably of about 0.1 to about 2
ml/g, as determined by mercury or water porosimetry. Further,
conventional hydroprocessing catalysts generally have a surface
area of at least about 10 m.sup.2/g, more preferably of at least
about 50 m.sup.2/g, and most preferably of at least about 100
m.sup.2/g, as determined via the B.E.T. method.
[0069] The median particle diameter of the metal compound or
compounds which are at least partly in the solid state during the
process of the invention is preferably is in the range from about
0.5 .mu.m to about 5000 .mu.m, more preferably from about 1 .mu.m
to about 500 .mu.m, and most preferably from about 2 .mu.m to about
150 .mu.m. Generally, the smaller the particle size of the metal
compounds, the higher their reactivity; in principle metal
compounds with particle sizes below the aforementioned preferred
lower limits would be desirable embodiments of the present
invention but for health, safety, and environmental reasons, the
handling of such small particles requires special precautions and
is thus not preferred.
[0070] Because of the presence of nano-sized particles during the
preparation of the bulk metal particles, the particle size
distribution and the pore size distribution of the bulk metal
particles shifts towards smaller particle diameters, compared to
bulk metal particles prepared in the absence of such nanoparticles.
Preferably the catalyst composition has a pore size distribution
wherein at least 75 percent of the total pore volume is in pores of
diameter from about 20 angstroms below the mode pore diameter to
about 20 angstroms above the mode pore diameter, less than 10
percent of said total pore volume is in pores of diameter less than
60 angstroms and greater than 3 percent to less than 10 percent of
said total pore volume is in pores of diameter greater than 110
angstroms, and said mode pore diameter of said composition is in
the range from about 70 to about 90 angstroms.
[0071] Typically, the surface area increases as a result of the
presence of the nanoparticles by at least 20%, more preferably at
least 30%, even more preferably at least 50%. Also the pore volume
decreases with nanoparticle addition. The pore diameter has been
found to decrease by more than 20%, or even more than 30%, or more
than 50%, when nanoparticles are used during preparation of the
bulk multimetallic particles. Preferably however, for VGO
hydrotreatment, the mean pore diameter (MPD) should not decrease
below a value of about 7 nm to retain sufficiently high catalyst
performance. In view of this effect and the fact that the activity
improvement appears to level off at high nanoparticle content, the
amount of nanoparticles added to the reaction mixture is preferably
less than about 10 wt.%, relative to the total amount of metals
used, calculated as metal oxides.
[0072] In the following, preferred process conditions during the
combination of the metal compounds and the (subsequent) reaction
step will be described:
Combination of the Metal Compounds
[0073] The process conditions during the combination of the metal
compounds generally are not critical. It is possible to add all
compounds at ambient temperature at their natural pH (if a
suspension or solution is applied). Generally, it is preferred to
keep the temperature of the added metal compounds below the
atmospheric boiling point of the reaction mixture to ensure easy
and safe handling of the compounds during the addition. However, if
desired, temperatures above the atmospheric boiling point of the
reaction mixture or different pH values may be applied. If the
reaction step is carried out at increased temperature, the
suspensions and optionally solutions, which are added to the
reaction mixture, generally can be pre-heated to an increased
temperature, which can be equal to the reaction temperature.
[0074] As has been mentioned above, the addition of one or more
metal compounds can also be carried out while already combined
metal compounds react with each other. In this case, the
combination of the metal compounds and the reaction thereof overlap
and constitute a single process step.
Reaction Step
[0075] The reaction can be monitored by conventional techniques
such as IR spectroscopy or Raman spectroscopy, wherein the reaction
is indicated by signal changes. In some cases, it is also possible
to monitor the reaction by monitoring changes in the pH of the
reaction mixture. Further, the completeness of the reaction can be
monitored by X-ray diffraction. This will be described in more
detail under the heading "Bulk catalyst composition of the
invention."
[0076] During and/or after their addition, the metal compounds
together with the nanoparticles, preferably the clay mineral
nanoparticles, are agitated at a certain temperature for a period
of time to allow the reaction to take place. The reaction
temperature is preferably in the range of about 0.degree. to about
300.degree. C., more preferably about 50.degree. to about
300.degree. C., even more preferably about 70.degree. to about
200.degree. C., and most preferably in the range of about
70.degree. to about 180.degree. C. If the temperature is below the
atmospheric boiling point of the reaction mixture, the process
generally is carried out at atmospheric pressure. Above this
temperature, the reaction generally is carried out at increased
pressure, preferably in an autoclave and/or static mixer.
[0077] Typically, the mixture is kept at its natural pH during the
reaction step; said pH is preferably in the range of about 0 to
about 12, more preferably in the range of about 1 to about 10, and
even more preferably in the range of about 3 to about 8. As has
been set out above, it is preferred that the pH and the temperature
are chosen in such a way that not all the metals are dissolved
during the reaction step.
[0078] The reaction time may lie in the range of about 1 minute to
several days depending on the reaction route chosen, but will
generally range from about 1 minute to about 100 hours. In the
process wherein at least one of the metal compounds is at least
partly in the solid state during the reaction, preferably about 1
hour to about 30 hours, more preferably about 4 to about 30 hours,
even more preferably about 10 to about 25 hours and more preferably
about 15 hours to about 25 hours. As has been mentioned above, the
reaction time depends on the temperature.
[0079] After the reaction step, if necessary, the solid can be
separated from any protic liquid that may remain using, for example
filtration. The process of the present invention can be carried out
both as a batch process and as a continuous process.
(B) Subsequent Process Steps
[0080] It is noted that the bulk metal particles resulting from the
process described above under (A) are metal oxide particles
Following the process described above under (A), the bulk metal
particles may be subjected to one or more of the following process
steps before being used in hydroprocessing processes:
[0081] i) compositing with further materials selected from the
group of binder materials, binder precursor materials, conventional
hydroprocessing catalysts, cracking compounds,
phosphorus-containing compounds, boron-containing compounds,
silicon-containing compounds, fluorine-containing compounds,
additional transition metals, rare earth metals or mixtures
thereof,
[0082] ii) spray-drying, (flash) drying, milling, kneading,
slurry-mixing, dry or wet mixing, or combinations thereof,
[0083] iii) shaping,
[0084] (iv) drying and/or thermally treating, and
[0085] (v) sulfiding,
[0086] The listing of these process steps as (i) to (v) is for
convenience only; it is not a statement that these processes are
constrained to be performed in this order. These process steps will
be explained in more detail in the following:
Process Step (i)
[0087] The aforementioned further compositing materials can be
performed at a plurality of stages during the preparation of the
bulk metal particles. However, because any addition of further
materials should not affect the interaction between the metal
compounds and the nanoparticles, it is preferred that the Group
VIB, Group VIII non-noble metal compounds and the nanoparticles are
combined and preferably at least partly reacted to bulk metal
particles before being combined with these further materials.
[0088] These materials can be added in the dry state, either
thermally treated or not, in the wetted and/or suspended state
and/or as a solution. They may be added prior to any step (ii)
and/or during and/or subsequent to any step (ii) but preferably
prior to a final shaping step (iii). Further additives may be
added, for example by impregnation, after shaping (these are not
referred to as further compositing materials)
[0089] Preferably, the material is added subsequent to the
preparation of the bulk metal particles and prior to spray-drying
or any alternative technique, or, if spray-drying or the
alternative techniques are not applied, prior to shaping.
Optionally, the bulk metal particles prepared as described above
can be subjected to a, solid-liquid separation before being
composited with the material. After solid-liquid separation,
optionally, a washing step can be included. Further, it is possible
to thermally treat the bulk catalyst particles after an optional
solid-liquid separation and drying step and prior to its being
composited with the material.
[0090] In all the above-described process alternatives, the term
"compositing the bulk metal particles with a material" means that
the material is added to the bulk metal particles or vice versa and
the resulting composition is mixed. Mixing is preferably done in
the presence of a liquid ("wet mixing"). This improves the
mechanical strength of the final bulk catalyst composition.
[0091] It has been found that compositing the bulk metal particles
with binder material and/or incorporating binder material during
the preparation of the bulk metal particles leads to bulk catalyst
compositions of particularly high mechanical strength, in
particular if the median particle size of the bulk metal particles
is in the range of at least about 0.5 m, more preferably at least
about most preferably at least about 2 .mu.m, but preferably not
more than about 5000 .mu.m, more preferably not more than about
1000 .mu.m, even more preferably not more than about 500 .mu.m, and
most preferably not more than about 150 .mu.m. Even more
preferably, the median particle diameter lies in the range of about
1 to about 150 .mu.m and most preferably in the range of about 2 to
about 150 .mu.m.
[0092] The compositing of the bulk metal particles with the
material results in bulk metal particles embedded in this material
or vice versa. Normally, the morphology of the bulk metal particles
is essentially maintained in the resulting bulk catalyst
composition.
[0093] As stated above, the material may be selected from the group
consisting of binder materials, binder precursor materials,
conventional hydroprocessing catalysts, cracking compounds,
phosphorus-containing compounds, boron-containing compounds,
silicon-containing compounds, fluorine-containing compounds,
additional transition metals, rare earth metals or mixtures
thereof, a binder material, a conventional hydroprocessing
catalyst, a cracking compound, or mixtures thereof. These materials
will be described in more detail below.
[0094] The binder materials to be applied may be any materials
conventionally applied as binders in hydroprocessing catalysts.
Examples are silica, silica-alumina, such as conventional
silica-alumina, silica-coated alumina and alumina-coated silica,
alumina such as (pseudo) boehmite, or gibbsite, titania,
titania-coated alumina, zirconia, hydrotalcite, or mixtures
thereof. Preferred binders are silica, silica-alumina, alumina,
titania, titania-coated alumina, zirconia, bentonite, or mixtures
thereof. These binders may be applied as such or after
peptization.
[0095] It is also possible to use precursors of these binders which
during the process of the invention are converted into any of the
above-described binders. Suitable precursors are, e.g., alkali
metal aluminates (to obtain an alumina binder), water glass (to
obtain a silica binder), a mixture of alkali metal aluminates and
water glass (to obtain a silica-alumina binder), aluminium
chlorohydrol, aluminium sulfate, aluminium nitrate, aluminium
chloride, or mixtures thereof.
[0096] If desired, the binder material may be composited with a
Group VIB metal-containing compound and/or a Group VIII non-noble
metal-containing compound, prior to being composited with the bulk
metal particles and/or prior to being added during the preparation
thereof. Compositing the binder material with any of these
metal-containing compounds may be carried out by impregnation of
the binder with these materials. Suitable impregnation techniques
are known to the person skilled in the art. If the binder needs to
be peptized, it is also possible to carry out the peptization in
the presence of Group VIB and/or Group VIII non-noble metal
containing compounds.
[0097] If alumina is used as binder, the surface area of the
alumina generally lies in the range of about 50 to about 600
m.sup.2/g and preferably about 100 to about 450 m.sup.2/g, as
measured by the B.E.T. method. The pore volume of the alumina
preferably is in the range of about 0.1 to about 1.5 ml/g, as
measured by nitrogen adsorption. Before the characterization of the
alumina, it is thermally treated at 600.degree. C. for 1 hour.
[0098] Generally, the binder material to be added in the process of
the invention has less catalytic activity than the bulk metal
particles or no catalytic activity at all. Consequently, by adding
a binder material, the activity of the bulk catalyst composition
may be reduced. Furthermore, the addition of binder material leads
to a considerable increase in the mechanical strength of the final
bulk catalyst composition. Therefore, the amount of binder material
to be added in the process of the invention generally depends on
the desired activity and/or desired mechanical strength of the
final bulk catalyst composition. Binder amounts from 0 to about 95
wt. % of the total composition can be suitable, depending on the
envisaged catalytic application. However, to take advantage of the
resulting unusually high activity of the bulk metal particles of
the present invention, the binder amounts to be added generally are
in the range of about 1 to about 75 wt. % of the total composition,
preferably about 1 to about 50 wt. %, more preferably about 1 to
about 30 wt. %, even more preferably about 3 to about 20 wt. %, and
most preferably about 4 to about 12 wt %.
[0099] The bulk metal particles of the present invention may also
be combined with conventional hydroprocessing catalysts include
known hydro-desulfurization, hydrodenitrogenation, or hydrocracking
catalysts. These catalysts can be added in the used, regenerated,
fresh, or sulfided state. If desired, the conventional
hydroprocessing catalyst may be milled or treated in any other
conventional way before being applied in the process of the
invention.
[0100] The bulk metal particles of the present invention may also
be combined with cracking components. A cracking compound according
to the present invention is any conventional cracking compound such
as cationic clays, anionic clays, crystalline cracking compounds
such as zeolites, e.g. ZSM-5, (ultra-stable) zeolite Y, zeolite X,
ALPOs, SAPOs, MCM-41, amorphous cracking compounds such as
silica-alumina, or mixtures thereof. It will be clear that some
materials may act as binder and cracking compound at the same time.
For instance, silica-alumina may have a cracking and a binding
function at the same time.
[0101] If desired, the cracking compound may be composited with a
Group VIB metal and/or a Group VIII non-noble metal prior to being
composited with the bulk metal particles. Compositing the cracking
compound with any of these metals may take the form of impregnation
of the cracking compound with these materials.
[0102] Generally, it depends on the envisaged catalytic application
of the final bulk catalyst composition which of the above-described
cracking compounds, if any, is added. A crystalline cracking
compound is preferably added if the resulting composition is to be
applied in hydrocracking. Other cracking compounds such as
silica-alumina or cationic clays are preferably added if the final
bulk catalyst composition is to be used in hydrotreating
applications or mild hydrocracking. The amount of cracking
material, which is added, depends on the desired activity of the
final composition and the application envisaged, and thus may vary
from 0 to about 90 wt. %, based on the total weight of the bulk
catalyst composition.
[0103] Phosphorus-containing compounds that may be combined with
the bulk metal particles include ammonium phosphate, phosphoric
acid or organic phosphorus-containing compounds.
Phosphorus-containing compounds can be added prior to the shaping
step and/or subsequent to the shaping step. If the binder material
needs to be peptized, phosphorus-containing compounds can also be
used for peptization. For instance, an alumina binder can be
peptized by being contacted with phosphoric acid or with a mixture
of phosphoric acid and nitric acid.
[0104] Boron-containing compounds that may be combined with the
bulk metal particles include boric acid or heteropoly compounds of
boron with molybdenum and/or tungsten. A fluorine-containing
compound that may typically be used is ammonium fluoride. Typical
silicon-containing compounds are water glass, silica gel,
tetraethylorthosilicate or heteropoly compounds of silicon with
molybdenum and/or tungsten. Further, compounds such as
fluorosilicic acid, fluoroboric acid, difluorophosphoric acid or
hexafluorophosphoric acid may be applied if a combination of F with
Si, B and P, respectively, is desired.
[0105] Suitable additional transition metals are, e.g., rhenium,
manganese, ruthenium, rhodium, iridium, chromium, vanadium, iron,
platinum, palladium, titanium, zirconium, niobium, cobalt, nickel,
molybdenum, or tungsten. These metals can be added at any stage of
the process of the present invention prior to the shaping step.
Apart from adding these metals during the process of the invention,
it is also possible to composite the final bulk catalyst
composition therewith. Thus it is possible to impregnate the final
bulk catalyst composition with an impregnation solution comprising
any of these metals.
Process Step (ii)
[0106] The bulk metal particles optionally comprising any of the
above (further) materials can be subjected to spray-drying, (flash)
drying, milling, kneading, slurry-mixing, dry or wet mixing, or
combinations thereof, with a combination of wet mixing and kneading
or slurry mixing and spray-drying being preferred.
[0107] These techniques can be applied either before or after any
of the above (further) materials are added (if at all), after
solid-liquid separation, before or after a thermal treatment, and
subsequent to re-wetting.
[0108] Preferably, the bulk metal particles are both composited
with any of the above materials and subjected to any of the above
techniques. It is believed that by applying any of the
above-described techniques of spray-drying, (flash) drying,
milling, kneading, slurry-mixing, dry or wet mixing, or
combinations thereof, the degree of mixing between the bulk metal
particles and any of the above materials is improved. This applies
to cases where the material is added before as well as after the
application of any of the above-described methods. However, it is
generally preferred to add the material prior to step (ii). If the
material is added subsequent to step (ii), the resulting
composition preferably is thoroughly mixed by any conventional
technique prior to any further process steps such as shaping. An
advantage of spray-drying is that no waste water streams are
obtained when this technique is applied.
[0109] Spray-drying typically is carried out at an outlet
temperature in the range of about 100.degree. to about 200.degree.
C. and preferably about 120.degree. to about 180.degree. C.
[0110] Dry mixing means mixing the bulk metal particles in the dry
state with any of the above materials in the dry state. Wet mixing
generally comprises mixing the wet filter cake comprising the bulk
metal particles and optionally any of the above materials as
powders or wet filter cake to form a homogenous paste thereof.
Process Step (iii)
[0111] If so desired, the bulk catalyst optionally comprising any
of the above (further) materials may be shaped optionally after
step (ii) having been applied. Shaping comprises extrusion,
pelletizing, beading and/or spray-drying. It must be noted that if
the bulk catalyst composition is to be applied in slurry-type
reactors, fluidized beds, moving beds, or expanded beds, generally
spray-drying or beading is applied. For fixed bed or ebullating bed
applications, generally the bulk catalyst composition is extruded,
pelletized and/or beaded. In the latter case, at any stage prior to
or during the shaping step, any additives which are conventionally
used to facilitate shaping can be added. These additives may
comprise aluminium stearate, surfactants, graphite, starch, methyl
cellulose, bentonite, polyethylene glycols, polyethylene oxides, or
mixtures thereof. Further, when alumina is used as binder, it may
be desirable to add acids such as nitric acid prior to the shaping
step to peptize the alumina and to increase the mechanical strength
of the extrudates.
[0112] If the shaping comprises extrusion, beading and/or
spray-drying, it is preferred that the shaping step is carried out
in the presence of a liquid, such as water. Preferably, for
extrusion and/or beading, the amount of liquid in the shaping
mixture, expressed as LOI, is in the range of about 20 to about
80%.
[0113] If so desired, coaxial extrusion of any of the above
materials with the bulk metal particles, optionally comprising any
of the above materials, may be applied. More in particular, two
mixtures can be co-extruded, in which case the bulk metal particles
optionally comprising any of the above materials are present in the
inner extrusion medium while any of the above materials without the
bulk metal particles is present in the outer extrusion medium or
vice versa.
Process Step (iv)
[0114] After an optional drying step, preferably above about
100.degree. C., the resulting shaped bulk catalyst composition may
be thermally treated if desired. A thermal treatment, however, is
not essential to the process of the invention. A "thermal
treatment" according to the present invention refers to a treatment
performed at a temperature of, e.g., from about 100.degree. to
about 600.degree. C., preferably from about 200.degree. to about
550.degree. C., more preferably about 250.degree. C. to about
450.degree. C., for a time varying from about 0.5 to about 48 hours
in an inert gas such as nitrogen, or in an oxygen-containing gas,
such as air or pure oxygen. The thermal treatment can be carried
out in the presence of water steam.
[0115] In all the above process steps the amount of liquid must be
controlled. Where, prior to subjecting the bulk catalyst
composition to spray-drying, the amount of liquid is too low,
additional liquid must be added. Conversely where, prior to
extrusion of the bulk catalyst composition, the amount of liquid is
too high, the amount of liquid must be reduced using solid-liquid
separation techniques such as filtration, decantation, or
evaporation and, if necessary, the resulting material can be dried
and subsequently re-wetted to a certain extent. For all the above
process steps, it is within the scope of the skilled person to
control the amount of liquid appropriately.
Process Step (v)
[0116] The process of the present invention may further comprise a
sulfidation step. Sulfidation generally is carried out by
contacting the bulk metal particles, directly after their
preparation or after any one of process steps (i)-(iv), with a
sulfur-containing compound such as elementary sulfur, hydrogen
sulfide, dimethyl disulfide (DMDS), or organic or inorganic
polysulfides. The sulfidation step can be carried out in the liquid
and the gaseous phase. The sulfidation can be carried out
subsequent to the preparation of the bulk catalyst composition but
prior to step (i) and/or subsequent to step (i) but prior to step
(ii) and/or subsequent to step (ii) but prior to step (iii) and/or
subsequent to step (iii) but prior to step (iv) and/or subsequent
to step (iv). It is preferred that the sulfidation is not carried
out prior to any process step by which the obtained metal sulfides
revert to their oxides. Such process steps are, e.g., a thermal
treatment or spray-drying or any other high-temperature treatment
if carried out under an oxygen-containing atmosphere. Consequently,
if the bulk catalyst composition is subjected to spray-drying
and/or any alternative technique or to a thermal treatment under an
oxygen-containing atmosphere, the sulfidation preferably is carried
out subsequent to the application of any of these methods. Of
course, if these methods are applied under an inert atmosphere,
sulfidation can also be carried out prior to these methods.
[0117] If the bulk catalyst composition is used in fixed bed
processes, the sulfidation preferably is carried out subsequent to
the shaping step and, if applied, subsequent to the last thermal
treatment in an oxidizing atmosphere.
[0118] The sulfidation can generally be carried out in situ and/or
ex situ. Preferably, the sulfidation is carried out ex situ, i.e.
the sulfidation is carried out in a separate reactor prior to the
sulfided bulk catalyst composition being loaded into the
hydroprocessing unit. Furthermore, it is preferred that the bulk
catalyst composition is sulfided both ex situ and in situ.
[0119] A preferred process of the present invention comprises the
following successive process steps of preparing the bulk metal
particles as described above, slurry mixing the obtained bulk metal
particles with, e.g., a binder, spray drying the resulting
composition, rewetting, kneading, extrusion, drying, calcining and
sulfiding. Another preferred process embodiment comprises the
following successive steps of preparing the bulk metal particles as
described above, isolating the particles via filtration, wet mixing
the filter cake with a material, such as a binder, kneading,
extrusion, drying, calcining and sulfiding.
Bulk Catalyst Composition of the Invention
[0120] The invention further pertains to a bulk catalyst
composition obtainable by the above-described process. Preferably,
the invention pertains to a bulk catalyst composition obtainable by
process step (A) and optionally one or more of process steps B
(i)-(v) described above.
[0121] In a preferred embodiment, the invention pertains to a bulk
catalyst composition obtainable by the above-described process
wherein the morphology of the metal compound(s), which are at least
partly in the solid state during the process is retained to some
extent in the bulk catalyst composition. This retention of
morphology is described in detail under the heading "Process of the
present invention."
Oxidic Bulk Catalyst Composition
[0122] Furthermore, the invention pertains to a bulk catalyst
composition comprising bulk metal particles which comprise at least
one Group VIII non-noble metal and at least one Group VIB metal,
wherein the metals are present in the bulk catalyst composition in
their oxidic state, and wherein the characteristic full width at
half maximum does not exceed 2.5.degree. when the Group VIB metal
is molybdenum, tungsten, a combination of molybdenum and tungsten,
or a combination of molybdenum, tungsten and chromium, or does not
exceed 4.0.degree. when the Group VIB metal is a combination of
molybdenum and chromium or a combination of tungsten and
chromium.
[0123] As described under the heading "characterization methods",
the characteristic full width at half maximum is determined on the
basis of the peak located at 2.theta.=53.9.degree.
(.+-.1.0.degree.) (when the Group VIB metal is molybdenum,
tungsten, a combination of molybdenum and tungsten, or a
combination of molybdenum, tungsten, and chromium) or at
2.theta.=63.5.degree. (.+-.0.6.degree.) when the Group VIB metal is
a combination of molybdenum and chromium, or a combination of
tungsten and chromium).
[0124] Preferably, the characteristic full width at half maximum
does not exceed 2.2.degree., more preferably 2.0.degree., still
more preferably 1.8.degree., and most preferably it does not exceed
1.6.degree. (when the Group VIB metal is molybdenum, tungsten, a
combination of molybdenum and tungsten, or a combination of
molybdenum, tungsten and chromium), or it does not exceed
3.5.degree., more preferably 3.0.degree., still more preferably
2.5.degree., and most preferably 2.0.degree. (when the Group VIB
metal is a combination of molybdenum and chromium, or a combination
of tungsten and chromium).
[0125] Preferably, the X-ray diffraction pattern shows peaks at the
positions 2.theta.=35.9.degree. (.+-.0.6.degree.), 38.7.degree.
(.+-.0.6.degree.), 40.8.degree. (.+-.0.7.degree.), 53.9
(.+-.1.0.degree.), and 64.5 (.+-.1.2.degree.) when the Group VIE
metals include tungsten. A typical X-ray diffraction pattern for a
metal oxide catalyst of the invention comprising tungsten is shown
in FIG. 1.
[0126] From the characteristic full width at half maximum of the
oxidic bulk catalyst compositions of the present invention, it can
be deduced that the microstructure of the catalyst of the present
invention differs from that of corresponding catalysts prepared via
co-precipitation as described in International Patent Application
Publication No. WO 9903578 or U.S. Pat. No. 3,678,124.
[0127] The X-ray diffraction pattern of the bulk metal particles
preferably does not contain any peaks characteristic of the metal
compounds to be reacted. Of course, if desired, it is also possible
to choose the amounts of metal compounds in such a way as to obtain
bulk metal particles characterized by an X-ray diffraction pattern
still comprising one or more peaks characteristic to at least one
of these metal compounds. If, e.g., a high amount of the metal
compound which is at least partly in the solid state during the
process of the invention is added, or if this metal compound is
added in the form of large crystalline particles, small amounts of
this metal compound may be traced in the X-ray diffraction pattern
of the resulting bulk metal particles.
[0128] The molar ratio of Group VIB to Group VIII non-noble metals
generally ranges from about 10:1 to about 1:10 and preferably from
about 3:1 to about 1:3. In the case of a core-shell structured
particle, these ratios of course apply to the metals contained in
the shell. The ratio of the different Group VIB metals to one
another generally is not critical. The same holds when more than
one Group VIII non-noble metal is applied. In cases where
molybdenum and tungsten are present as Group VIB metals, the
molybenum:tungsten ratio preferably lies in the range of about 9:1
to about 1:19, more preferably about 3:1 to about 1:9, most
preferably about 3:1 to about 1:6.
[0129] The bulk metal particles may comprise only one Group VIII
non-noble metal and only one Group VIB metal compound. In this
embodiment, preferred bimetallic combinations comprise
nickel-tungsten, cobalt-tungsten, nickel-molybdenum and
cobalt-molybdenum, more preferably, nickel-tungsten.
[0130] The bulk metal particles may however equally comprise at
least one Group VIII non-noble metal compound and at least two
Group VIB metal compounds. Suitable Group VIB metals include
chromium, molybdenum, tungsten, or mixtures thereof, with a
combination of molybdenum and tungsten being most preferred.
Suitable Group VIII non-noble metals include iron, cobalt, nickel,
or mixtures thereof, preferably nickel and/or cobalt. Preferably, a
combination of metals comprising nickel, molybdenum, and tungsten
or nickel, cobalt, molybdenum, and tungsten, or cobalt, molybdenum,
and tungsten is contained in the bulk metal particles of the
invention.
[0131] Preferably, the oxidic bulk metal particles comprised in
these bulk catalyst compositions have a B.E.T. surface area of at
least about 10 m.sup.2/g, more preferably of at least about 50
m.sup.2/g, and most preferably of at least about 80 m.sup.2/g, as
measured via the B.E.T. method.
[0132] If during the preparation of the bulk metal particles none
of the above (further) materials, such as a binder material, a
cracking compound or a conventional hydroprocessing catalyst, have
been added, the bulk catalyst particles will comprise about 85 to
about 99.5 wt. % of Group VIB and Group VIII non-noble metals. If
any of the above materials have been added during the preparation
of the bulk metal particles, they will still preferably comprise
greater than about 50 wt. %, and more preferably greater than about
70 wt. % of the Group VIB and Group VIII non-noble metals,
calculated as oxides and based on the total weight of the bulk
metal particles, the balance being any of the above-mentioned
(further) materials. The amount of Group VIB and Group VIII
non-noble metals can be determined via TEM-EDX, SEM-EDX, AAS, ICP
and/or appropriate combinations of these methodologies. TEM and
SEM-EDX is used to determine concentrations on nanometer or
micrometer scale; AAS and ICP are bulk methods.
[0133] The median pore diameter (50% of the pore volume is below
said diameter, the other 50% above it) of the oxidic bulk metal
particles preferably is about 1 to about 25 nm, more preferably
about 2 to about 15 inn and most preferably about 5 to about 15 nm
(determined by N.sub.2 adsorption).
[0134] The total pore volume of the oxidic bulk metal particles
preferably is at least about 0.05 ml/g, more preferably at least
about 0.1 ml/g, and most preferably greater than about 0.2 mug as
determined by N.sub.2 adsorption.
[0135] It is desired that the pore size distribution of the bulk
metal particles is similar to that of conventional hydroprocessing
catalysts. More particularly, the bulk metal particles preferably
have a median pore diameter of about 3 to about 25 nm, as
determined by nitrogen adsorption, a pore volume of about 0.05 to
about 5 ml/g, more preferably of about 0.05 to about 4 ml/g, still
more preferably of about 0.05 to about 3 ml/g, and most preferably
of about 0.1 to about 2 ml/g, as determined by nitrogen
adsorption.
[0136] Furthermore, these bulk metal particles preferably have a
median particle size in the range of at least about 0.5 .mu.m, more
preferably at least about 1 .mu.m, most preferably at least about 2
.mu.m, but preferably not more than about 5000 .mu.m, more
preferably not more than about 1000 .mu.m, even more preferably not
more than about 500 .mu.m, and most preferably not more than about
150 .mu.m. Even more preferably, the median particle diameter lies
in the range of about 1 to about 150 .mu.m and most preferably in
the range of about 2 to about 150 .mu.m.
[0137] As has been mentioned above, if so desired, it is possible
to prepare core-shell structured bulk metal particles using the
process of the invention. In these particles, at least one of the
metals is anisotropically distributed in the bulk metal particles.
The concentration of a metal, the metal compound of which is at
least partly in the solid state during the process of the
invention, generally is higher in the inner part, i.e., the core of
the final bulk metal particles, than in the outer part, i.e. the
shell of the final bulk metal particles. Generally, the
concentration of this metal in the shell of the final bulk metal
particles is at most about 95% and in most cases at most about 90%
of the concentration of this metal in the core of the final bulk
metal particles. Further, it has been found that the metal of a
metal compound, which is applied in the solute state during the
process of the invention, is also anisotropically distributed in
the final bulk metal particles. More particularly, the
concentration of this metal in the core of the final bulk metal
particles generally is lower than the concentration of this metal
in the shell. Still more particularly, the concentration of this
metal in the core of the final bulk metal particles is at most
about 80% and frequently at most about 70% and often at most about
60% of the concentration of this metal in the shell. It must be
noted that the above-described anisotropic metal distributions, if
any, can be found in the bulk catalyst composition of the invention
irrespective of whether the bulk catalyst composition has been
thermally treated and/or sulfided. In the above cases, the shell
generally has a thickness of about 10 to about 1,000 nm.
[0138] Though the above anisotropic metal distribution can be
formed/obtained during the process of the invention, the Group VIB
and Group VIII non-noble metals generally are homogeneously
distributed in the bulk metal particles. This embodiment generally
is preferred.
[0139] Preferably, the bulk catalyst composition additionally
comprises a suitable binder material. Suitable binder materials
preferably are those described above. The particles generally are
embedded in the binder material, which functions as a glue to hold
the particles together. Preferably, the particles are homogeneously
distributed within the binder. The presence of the binder generally
leads to an increased mechanical strength of the final bulk
catalyst composition. Generally, the bulk catalyst composition of
the invention has a mechanical strength, expressed as side crush
strength, of at least about 1 lbs/mm and preferably of at least
about 3 lbs/mm (measured on extrudates with a diameter of 1-2
mm).
[0140] The amount of binder depends inter alia on the desired
activity of the bulk catalyst composition. Binder amounts from 0 to
about 95 wt. % of the total composition can be suitable, depending
on the envisaged catalytic application. However, to take advantage
of the unusually high activity of the composition of the present
invention, the binder amounts generally are in the range of 0 to
about 75 wt. % of the total composition, preferably 0 to about 50
wt. %, more preferably 0 to about 30 wt. %.
[0141] If desired, the bulk catalyst composition may comprise a
suitable cracking compound. Suitable cracking compounds preferably
are those described above. The amount of cracking compound
preferably is in the range of 0 to about 90 wt. %, based on the
total weight of the bulk catalyst composition.
[0142] Moreover, the bulk catalyst composition may comprise
conventional hydroprocessing catalysts. The conventional
hydroprocessing catalyst generally comprises any of the
above-described binder materials and cracking compounds. The
hydrogenation metals of the conventional hydroprocessing catalyst
generally comprise Group VIB and Group VIII non-noble metals such
as combinations of nickel or cobalt with molybdenum or tungsten.
Suitable conventional hydroprocessing catalysts include
hydrotreating or hydrocracking catalysts. These catalysts can be in
the used, regenerated, fresh, or sulfided state.
[0143] Furthermore, the bulk catalyst composition may comprise any
further material, which is conventionally present in
hydroprocessing catalysts such as phosphorus-containing compounds,
boron-containing compounds, silicon-containing compounds,
fluorine-containing compounds, additional transition metals, rare
earth metals, or mixtures thereof. Details in respect of these
further materials are given above. The transition or rare earth
metals generally are present in the oxidic form when the bulk
catalyst composition has been thermally treated in an oxidizing
atmosphere and/or in the sulfided form when the bulk catalyst
composition has been sulfided.
[0144] To obtain bulk catalyst compositions with high mechanical
strength, it may be desirable for the bulk catalyst composition of
the invention to have a low macroporosity. Preferably, less than
about 30% of the pore volume of the bulk catalyst composition is in
pores with a diameter higher than about 100 nm (determined by
mercury intrusion, contact angle: 130.degree.), more preferably
less than about 20%.
[0145] The oxidic bulk catalyst composition of the present
invention generally comprises about 10 to about 100 wt. %,
preferably about 25 to about 100 wt. %, more preferably about 45 to
about 100 wt. % and most preferably about 65 to about 100 wt. % of
Group VIB and Group VIII non-noble metals, based on the total
weight of the bulk catalyst composition, calculated as metal
oxides.
[0146] It is noted that a catalyst prepared via stepwise
impregnation with Group VIB and Group VIII non-noble metal
solutions on an alumina carrier as described in JP 09000929 does
not comprise any bulk metal particles and thus has a morphology
which is completely different from that of the present
invention.
Sulfided Bulk Catalyst Composition
[0147] If so desired, the bulk catalyst composition of the present
invention can be sulfided. Consequently, the present invention
further pertains to a bulk catalyst composition comprising sulfidic
bulk metal particles, which comprise at least one Group VIII
non-noble metal and at least one Group VIB metal, and wherein the
degree of sulfidation under conditions of use does not exceed about
90%.
[0148] It will be clear that the above sulfided bulk catalyst
composition may comprise any of the above-described (further)
materials.
[0149] The present invention further pertains to a shaped and
sulfided bulk catalyst composition comprising
[0150] i) sulfidic bulk metal particles comprising nanoparticles,
at least one Group VIII non-noble metal and at least two Group VIB
metals, wherein the degree of sulfidation under conditions of use
does not exceed about 90%, and
[0151] ii) a material selected from the group of binder materials,
conventional hydroprocessing catalysts, cracking compounds, or
mixtures thereof.
[0152] It is essential that the degree of sulfidation of the
sulfidic bulk metal particles under conditions of use does not
exceed about 90%. Preferably, the degree of sulfidation under
conditions of use is in the range of about 10 to about 90%, more
preferably of about 20 to about 90%, and most preferably of about
40 to about 90%. The degree of sulfidation is determined as
described under the heading "characterization methods."
[0153] If conventional sulfidation techniques are applied in the
process of the present invention, the degree of sulfidation of the
sulfidic bulk metal particles prior to use is essentially identical
to the degree of sulfidation under conditions of use. However, if
very specific sulfidation techniques are applied, it might be that
the degree of sulfidation prior to the use of the catalyst is
higher than during the use thereof; as during use part of the
sulfides or elemental sulfur is removed from the catalyst. In this
case the degree of sulfidation is the one that results during use
of the catalyst and not prior thereto. The conditions of use are
those described below in the chapter "use according to the
invention." That the catalyst is "under conditions of use" means
that it is subjected to these conditions for a time period long
enough for the catalyst to reach equilibrium with its reaction
environment.
[0154] It is further preferred that the bulk catalyst composition
of the present invention is essentially free of Group VIII
non-noble metal disulfides. More in particular, the Group VIII
non-noble metals are preferably present as (Group VIII non-noble
metal).sub.yS.sub.x, with x/y being in the range of about 0.5 to
about 1.5
[0155] The shaped and sulfided catalyst particles may have many
different shapes. Suitable shapes include spheres, cylinders,
rings, and symmetric or asymmetric polylobes, for instance and
quadrulobes. Particles resulting from extrusion, beading or pilling
usually have a diameter in the range of about 0.2 to about 10 mm,
and their length likewise is in the range of about 0.5 to about 20
mm. Particles resulting from spray-drying generally have a median
particle diameter in the range of about 1 .mu.m to about 100
.mu.m.
[0156] Details about the binder materials, cracking compounds,
conventional hydro-processing catalysts, and any further materials
as well as the amounts thereof are given above. Further, details in
respect of the Group VIII non-noble metals and the Group VIB metals
contained in the sulfided bulk catalyst compositions and the
amounts thereof are given above.
[0157] It is noted that the core-shell structure described above
for the oxidic bulk catalyst composition is not destroyed by
sulfidation, i.e., the sulfided bulk catalyst compositions may also
comprise this core-shell structure.
[0158] It is further noted that the sulfided catalysts are at least
partly crystalline materials, i.e., the X-ray diffraction pattern
of the sulfided bulk metal particles generally comprises several
crystalline peaks characteristic to the Group VIII non-noble metal
and Group VIB metal sulfides.
[0159] As for the oxidic bulk catalyst composition, preferably,
less than about 30% of the pore volume of the sulfidic bulk
catalyst composition is in pores with a diameter higher than about
100 nm (determined by mercury intrusion, contact angle:
130.degree.), more preferably less than about 20%.
[0160] Generally, the median particle diameters of the sulfidic
bulk metal particles are identical to those given above for the
oxidic bulk metal particles.
Use According to the Invention
[0161] The bulk catalyst composition according to the invention is
particularly useful for hydroprocessing hydrocarbon feedstocks.
Accordingly, the invention relates to a process for hydroprocessing
a hydrocarbon feedstock, said process comprising contacting a
hydrocarbon feedstock under hydroprocessing conditions with a
catalyst composition comprising bulk metal particles that comprise
at least one Group VIII non-noble metal, at least one Group VIB
metal and nanoparticles.
[0162] The catalyst composition according to the invention can be
used in virtually all hydroprocessing processes to treat a
plurality of feeds under wide-ranging reaction conditions such as
temperatures of from 100 to 450.degree. C., hydrogen pressures of
from 5 to 1200 bar, preferably below 300 bars, liquid hourly space
velocities of from 0.05 to 10 h.sup.-1 and hydrogen treat gas rates
of from about 18 to about 1800 m.sup.3/m.sup.3 (100 to 10,000
SCF/B). The term hydroprocessing used in the context of this
invention encompasses all processes in which a hydrocarbon
feedstock is reacted with hydrogen at the temperatures and
pressures noted above, and including hydrogenation,
hydrodesulfurization, hydrodenitrogenation, hydrodemetallization,
hydrodearomatization, hydroisomerization, hydrodewaxing,
hydrotreating, hydrofinishing and hydrocracking.
[0163] The catalyst composition of the invention is particularly
effective for the removal of nitrogen and sulfur from a hydrocarbon
feed. Accordingly, in a preferred embodiment, the catalyst of the
invention is used to remove sulfur, nitrogen, or a combination of
sulfur and nitrogen, from hydrocarbon feedstocks. The contacting of
the hydrocarbon feedstock with the catalyst composition occurs in
the presence of a hydrogen-containing treat gas, and the reaction
is operated under effective hydroprocessing conditions. The
contacting of the hydrocarbon feedstock with the catalyst
composition produces a hydrocarbon product, liquid under
atmospheric conditions, that has less nitrogen, sulfur, or both,
compared to the feedstock.
[0164] The hydrocarbon feedstock is a material comprising hydrogen
and carbon. A wide range of petroleum and chemical hydrocarbon
feedstocks can be hydroprocessed in accordance with the present
invention. Hydrocarbon feedstocks include those obtained or derived
from crude petroleum oil, from tar sands, from coal liquefaction,
from shale oil and from hydrocarbon synthesis, such as reduced
crudes, hydrocrackates, raffinates, hydrotreated oils, atmospheric
and vacuum gas oils, coker gas oils, atmospheric and vacuum resids,
deasphalted oils, dewaxed oils, slack waxes, Fischer-Tropsch waxes
and mixtures thereof. Suitable feedstocks range from relatively
light distillate fractions up to heavy feedstocks, such as gas
oils, lube oils and resids. Non-limiting examples of light
distillate feedstocks include naphtha (typical boiling range of
from about 25.degree. C. to about 210.degree. C.), diesel (typical
boiling range of from about 150.degree. C. to about 400.degree.
C.), kerosene or jet fuel (typical boiling range of from about
150.degree. C. to about 250.degree. C.) and the like. Non-limiting
examples of heavy feedstocks include vacuum (or heavy) gas oils
(typical boiling range of from about 315.degree. C. to about
610.degree. C.), raffinates, lube oils, cycle oils, waxy oils and
the like. Preferred hydrocarbon feedstocks have a boiling range of
from about 150.degree. C. to about 650.degree. C., conveniently
from about 150.degree. C. to about 450.degree. C.
[0165] The catalyst composition of the present invention is
particularly effective for removing sulfur, nitrogen or a
combination of sulfur and nitrogen from hydrocarbon feedstocks.
Hydrocarbon feedstocks indeed often contain nitrogen and sulfur
contaminants, often in the form of sulfur and/or
nitrogen-containing organic compounds. The nitrogen content of the
feedstock can be up to about 5000 wppm nitrogen, preferably up to
about 2000 wppm nitrogen, more preferably up to 1000 wppm nitrogen
and most preferably up to 500 wppm nitrogen. Nitrogen contaminants
may be basic or non-basic. Examples of basic nitrogen contaminants
include quinolines and substituted quinolines, and examples of
non-basic nitrogen species include carbazoles and substituted
carbazoles. The sulfur content of the feedstock may be from 0.05 wt
% to 3 wt %, and is typically less than 2 wt %.
[0166] In a preferred embodiment, effective hydroprocessing
conditions are effective hydrotreating conditions, that is,
conditions effective for at least one of (i) hydrogenation or (ii)
hydrogenolysis. Generally, hydrotreating conditions will result in
removing at least a portion of the heteroatoms in the feed and in
hydrogenating at least a portion of the aromatics in the feed.
Hydrotreating conditions typically include temperatures ranging
from about 100.degree. C. to about 450.degree. C., preferably from
about 200.degree. C. to about 370.degree. C., more preferably from
about 230.degree. C. to about 350.degree. C. Typical liquid hourly
space velocities ("LHSV") range from about 0.05 to about 20
hr.sup.-1, preferably from about 0.5 to about 5 hr.sup.-1. Any
effective pressure can be utilized, and pressures typically range
from about 5 to about 250 bar. Hydrogen (H.sub.2) to oil ratio
generally ranges from about 18 to about 1800 m.sup.3/m.sup.3 (100
to 10000 SCF/B). Process conditions may vary, as is known to those
skilled in the art, depending on the feed boiling range and
speciation. Generally, as the boiling point of the feed increases,
the severity of the conditions will also increase. The following
table serves to illustrate typical conditions for a range of
feeds.
TABLE-US-00001 SPACE TYPICAL VELOC- H.sub.2 GAS BOILING TEMP.
PRESS, ITY RATE FEED RANGE .degree. C. .degree. C. BAR V/V/HR SCF/B
Naphtha 25-210 100-370 10-60 0.5-10 100-2,000 Diesel 150-400
200-400 15-110 0.5-4 500-6,000 Heavy 315-610 260-430 15-170 0.3-2
1000-6,000 Gas Oil Lube 290-550 200-450 6-210 0.2-5 100-10,000 Oil
Resid 10-50% > 340-450 65-1100 0.1-1 2,000-10,000 575
[0167] The process uses hydrogen or a hydrogen-containing treat
gas. Treat gas can comprise substantially pure hydrogen or can be
mixtures of other components typically found in refinery hydrogen
streams. It is preferred that the treat gas contain little, more
preferably no, hydrogen sulfide. The treat gas purity should be at
least about 50% by volume hydrogen, preferably at least about 75%
by volume hydrogen, and more preferably at least about 90% by
volume hydrogen. The treat gas can be pure or substantially pure
hydrogen.
[0168] The hydroprocessing occurs in a reaction stage. The reaction
stage can comprise one or more reactors or reaction zones each of
which comprises one or more catalyst beds of the same or different
catalyst. At least one bed will contain the catalyst composition of
the invention. Although other types of catalyst beds/reactors can
be used, fixed beds are preferred. Such other types of catalyst
beds include fluidized beds, ebullating beds, slurry beds, and
moving beds. Interstage cooling or heating between reactors,
reaction zones, or between catalyst beds in the same reactor, can
be employed. A portion of the heat generated during hydroprocessing
can be recovered. Where this heat recovery option is not available,
conventional cooling may be performed through cooling utilities
such as cooling water or air, or through use of a hydrogen quench
stream. In this manner, optimum reaction temperatures can be more
easily maintained.
Characterization Methods
[0169] The methods described below represent those characterization
methods deemed most appropriate for this invention. However, the
skilled person would be aware of other techniques, such as Raman or
Infrared spectroscopy that could equally be employed in
characterization of products.
1. Side Crush Strength Determination
[0170] First, the length of, e.g., an extrudate particle was
measured, and then the extrudate particle was subjected to
compressive loading (25 lbs in 8.6 sec.) by a movable piston. The
force required to crush the particle was measured. The procedure
was repeated with at least 40 extrudate particles and the average
was calculated as force (lbs) per unit length (mm). The method
preferably was applied to shaped particles with a length not
exceeding 7 mm.
2. Pore Volume Via N.sub.2 Adsorption
[0171] The N.sub.2 adsorption measurement was carried out as
described in the Ph.D. dissertation of J. C. P. Broekhoff (Delft
University of Technology 1969), the disclosure of which is hereby
incorporated by reference.
3. Amount of Added Solid Metal Compounds
[0172] Qualitative determination: The presence of solid metal
compounds during the process of the invention can easily be
detected by visual inspection at least if the metal compounds are
present in the form of particles with a diameter larger than the
wavelength of visible light. Of course, methods such as
quasi-elastic light scattering (QELS) or near-forward scattering,
which are known to the skilled person, can also be used to verify
that at no point in time during the process of the invention all
metals will be in the solute state.
[0173] Quantitative determination: if the metal compounds which are
added at least partly in the solid state are added as
suspension(s), the amount of solid metal compounds added during the
process of the invention can be determined by filtration of the
suspension(s) to be added under the conditions which are applied
during the addition (temperature, pH, pressure, amount of liquid),
in such a way that all solid material contained in the
suspension(s) is collected as solid filter cake. From the weight of
the solid and dried filter cake, the weight of the solid metal
compounds can be determined by standard techniques. Of course, if
apart from solid metal compounds further solid compounds, such as a
solid binder, are present in the filter cake, the weight of this
solid and dried binder must be subtracted from the weight of the
solid and dried filter cake.
[0174] The amount of solid metal compounds in the filter cake can
also be determined by standard techniques such as atomic absorption
spectroscopy (AAS), XRF, wet chemical analysis, or ICP.
[0175] If the metal compounds, which are added at least partly in
the solid state, are added in the wetted or dry state, a filtration
generally is not possible. In this case, the weight of the solid
metal compounds is considered equal to the weight of the
corresponding initially employed metal compounds, on a dry basis.
The total weight of all metal compounds is the amount of all metal
compounds initially employed, on a dry basis, calculated as metal
oxides.
4. Characteristic Full Width at Half Maximum
[0176] The characteristic full width at half maximum of the oxidic
catalysts was determined on the basis of the X-ray diffraction
pattern of the catalysts using a linear background:
[0177] a) if the Group VIB metals are molybdenum and tungsten: the
characteristic full width at half maximum is the full width at half
maximum (in terms of 20) of the peak at 2.theta.=53.6.degree.
(.+-.0.7.degree.),
[0178] b) if the Group VIB metals are molybdenum and chromium: the
characteristic full width at half maximum is the full width at half
maximum (in terms of 2.theta.) of the peak at)
2.theta.=63.5.degree. (.+-.0.6.degree.),
[0179] c) if the Group VIB metals are tungsten and chromium: the
characteristic full width at half maximum is the full width at half
maximum (in terms of 2.theta.) of the peak at 2.theta.=53.6.degree.
(.+-.0.7.degree.),
[0180] d) if the Group VIB metals are molybdenum, tungsten, and
chromium: the characteristic full width at half maximum is the full
width at half maximum (in terms of 2.theta.) of the peak at
2.theta.=53.6.degree. (.+-.0.7.degree.).
[0181] For the determination of the X-ray diffraction pattern, a
standard powder diffractometer (e.g., Philips PW1050) equipped with
a graphite monochromator can be used. The measurement conditions
can be chosen as follows: [0182] X-ray generator settings: 40 kV
and 40 mA [0183] wavelength: 1.5418 angstroms [0184] divergence and
anti-scatter slits: 1.degree. [0185] detector slit: 0.2 mm, [0186]
step size: 0.04 (.degree. 2.theta.) [0187] time/step: 20
seconds
5. Degree Of Sulfidation
[0188] Any sulfur contained in the sulfidic bulk catalyst
composition was oxidized in an oxygen flow by heating in an
induction oven. The resulting sulfur dioxide was analyzed using an
infrared cell with a detection system based on the IR
characteristics of the sulfur dioxide. To obtain the amount of
sulfur the signals relating to sulfur dioxide are compared to those
obtained on calibration with well-known standards. The degree of
sulfidation is then calculated as the ratio between the amount of
sulfur contained in the sulfidic bulk metal particles and the
amount of sulfur that would be present in the bulk metal particles
if all Group VIB and Group VIII non-noble metals were present in
the form of their disulfides.
[0189] It will be clear to the skilled person that the catalyst,
the degree of sulfidation of which is to be measured, is to be
handled under an inert atmosphere prior to the determination of the
degree of sulfidation.
6. Dimension of the Nanoparticles
[0190] The dimension of the dispersed nanoparticles can be
determined by transmission electron microscopy (TEM) (for example,
after careful evaporation of a suspension of dispersed particles,
or, as the clay nanoparticles have different morphology than the
bulk catalyst, by TEM analysis of bulk catalyst particles), or by
light scattering methods (f. ex. in the slurry). Although an
accurate and absolute value for the dimension is difficult to
establish, it is for the purposes of the invention sufficient to
determine that a sufficiently large part, preferably at least about
50%, has a size below one micrometer. This assessment can be done
by taking a TEM picture as is known by the person skilled in the
art and assessing on a representative picture, preferably covering
an area of at least about 500 by about 500 nanometer, whether there
are a substantial number of particles having a size less than about
500 nanometer.
[0191] The invention will be further illustrated by the following
Examples.
Example E1
Ni1Mo0.5W0.5+3 w % Laponite
[0192] 20.3 g of laponite (LOI=11.2%, Laponite RD available from
Rockwood Additives Limited) was suspended in water in a separate
stirred vessel for approximately one hour. According to the
supplier specification, disc-like platelets of about 0.92 nm
thickness and having a lateral dimension of about 25 nm and a
surface area of over 900 m.sup.2g should be obtained after complete
delamination. The particle length and stacking was verified using
TEM. Most of the clay particles indeed consisted of a single layer
about 25 mm long. However, a small portion of the clay particles
was not fully delaminated, i.e. the particles were longer (up to 60
nm) and consisted of multiple layers (up to 5 layers.)
[0193] Separately, 1211 g of nickel hydroxy carbonate paste (10.7
wt. % Ni: 2.21 mol Ni) was suspended in water and the mixture was
stirred until the slurry became homogeneous. Then 161 g of
MoO.sub.3 (99.1% MoO.sub.3, 1.1 mol Mo) and 277 g H.sub.2WO.sub.4
(92.7 wt % WO.sub.3, 1.03 mol W) were added to the nickel slurry
and the mixture was stirred until the slurry became homogeneous.
Then the laponite suspension was added and the mixture was stirred
until the slurry became homogeneous. The reaction was carried out
in an open vessel. The reaction mixture was stirred during the
entire process, i.e. when combining the raw materials and when
reacting them. The reaction was carried out by increasing the
temperature to 95.degree. C. and maintaining the mixture at that
temperature for 24 hours. The pH of the reaction mixture was 5.2 at
the start of the reaction time and 5.0 at the end of the reaction
time.
[0194] The slurry was then allowed to cool down and was then
filtered. The resulting filter cake was combined with surfactant
and 15.3 gr of attapulgite (LOI=20.5%), a needle-like clay mineral
composed of magnesium-aluminum silicate having a lateral dimension
above 1 micrometer in a kneader. Furthermore, 27.6 g of
microgranular SiO.sub.2 (LOI=11.8 wt. %, surface area of about 190
m.sup.2/g, median particle diameter of 22 micrometer) was added to
the cake. Depending on the water content of the filter cake, the
water content of the extrusion mix was adjusted (by adding water or
by evaporating water) to obtain an extrudable mix. The mix was then
extruded, dried in air at 120.degree. C. overnight and calcined at
340.degree. C. for 1/2 hour. The amount of laponite (relative to
the total amount of metal oxides+laponite) was 3.0 wt %. The amount
of laponite in the end product (=final calcined catalyst including
also ca. 1.9 wt. % attapulgite and ca. 3.8 wt. % silica) was 2.8
wt. %. This catalyst was then sulfided and tested as described
below in Test Procedures 1 and 2.
Comparative Experiment C1 (Ni1Mo0.5W0.5)
[0195] In this experiment, Example E1 was repeated without the
addition of the laponite suspension. This catalyst was then
sulfided and tested as described below in Test Procedures 1 and
2.
Testing E1 and C1 by Test Procedures 1 and 2
[0196] The catalysts prepared in examples E1 and C1 were tested in
Test Procedure 1 described below in the hydrotreatment of a Vacuum
Gas Oil, (VGO) feedstock using 4 different test conditions (TC1.1
to TC 1.4, respectively) and in Test Procedure 2 in the
hydrotreatement of Ultra Low Sulfur Diesel (ULSD) feedstock using
in 2 different test conditions (TC2.1 and TC2.2, respectively). The
test conditions and the test results are given in Table 3. For each
test procedure the residual sulfur level (S in ppm) and nitrogen (N
in ppm) is given with the activity (relative volume activity RVA)
for sulfur removal (HDS) and nitrogen removal (HDN). For each test
condition, the activity of the catalyst of the comparative
experiment was set at 100% and the activity of the catalysts
according to the invention was expressed in percentage relative to
the comparative catalyst. CBD is the compacted bulk density of the
catalyst. Details of the test procedure are described in more
detail below.
Test Procedure 1: VGO Testing
[0197] The catalysts were tested in an upflow tubular reactor. Each
reactor tube contained 50 ml of catalyst mixed with an equal amount
of SiC particles and sandwiched between layers of SIC particles.
Before testing the catalysts were presulfided via liquid phase
presulfiding, using the feed described below in Table 1 which had
been spiked with dimethyl disulfide to a total sulfur content of
3.7 wt. % at temperature of 320.degree. C., a pressure of 40 bar, a
hydrogen to oil ratio (Nl/l) of 300 and at a liquid hourly space
volume (LHSV) (1/h) of 1.76. The presulfided catalysts were then
tested in the hydrotreating of a VGO feedstock having the
properties shown in Table 1.
TABLE-US-00002 TABLE 1 VGO FEED Feed Density at 15.degree. C.
(g/ml) 0.9207 Density at 50.degree. C. (g/ml) 0.8964 Hydrogen
Content (% wt.) 12.2 Sulfur Content (% wt.) 1.6297 Nitrogen Content
(ppmwt.) 1714 Pour Point (.degree. C.) 46 Viscosity at 50.degree.
C. (mm.sup.2/s) 25.91 Total Aromatics 46.1 ASTM Distillation IBP
(.degree. C.) 268.2 V05 (.degree. C.) 340.4 V10 (.degree. C.) 370.0
V20 (.degree. C.) 407.6 V30 (.degree. C.) 433.6 V40 (.degree. C.)
455.7 V50 (.degree. C.) 475.9 V60 (.degree. C.) 495.0 V70 (.degree.
C.) 514.4 V80 (.degree. C.) 536.7 V90 (.degree. C.) 563.6 V95
(.degree. C.) 578.7 FBP (.degree. C.) 611.4
[0198] The results of the VGO test for the catalysts of examples E1
and C1 are shown in Table 3.
Test Procedure 2: ULSD Testing
[0199] The catalysts were tested in the same way as in Test
Procedure 1, except the amount of catalyst was 10 ml instead of 50
ml, the liquid hourly space volume (LHSV) (1/h) was 3.00 instead of
1.76 and the feedstock spiked with dimethyl disulfide was the ultra
low sulfur feed of Table 2. The presulfided catalysts were then
tested in the hydrotreating of a diesel feedstock having the
properties shown in Table 2:
TABLE-US-00003 TABLE 2 ULTRA LOW SULFUR DIESEL FEED S (wt. %) 1.2 N
(ppmwt) 102 Total aromatics (wt. %) 28.3 Polynuclear aromatic (PNA)
(wt. %) 11.8 Mono-aromatics (wt. %) 16.5 Di-aromatics (wt. %) 11.0
Di+-aromatics (wt. %) 0.8 Simulated distillation ASTM-D 86 Initial
boiling point 178.4.degree. C. 5 vol. % 211.1.degree. C. 10 vol. %
224.0.degree. C. 30 vol. % 261.4.degree. C. 50 vol. % 283.8.degree.
C. 70 vol. % 309.3.degree. C. 90 vol. % 347.8.degree. C. Final
boiling point 372.0.degree. C.
[0200] The results of the VGO test for the catalysts of examples E1
and C1 are shown in Table 3.
TABLE-US-00004 TABLE 3 H.sub.2/OIL LHSV CBD S N RVA RVA SAMPLE
COMPOSITION TEST T (.degree. C.) P (bar) (Nl/l) (1/h) loaded ppm
ppm HDS HDN VGO E1.1 Ni1Mo0.5W0.5, 3 wt % Lap TC1.1 360 120 1000
1.25 1.22 44.6 155 116 121 C1.1 Ni1Mo0.5W0.5 TC1.1 360 120 1000
1.25 1.12 53.7 232 100 100 E1.2 Ni1Mo0.5W0.5, 3 wt % Lap TC1.2 370
120 1000 1.25 1.22 9.1 35 130 115 C1.2 Ni1Mo0.5W0.5 TC1.2 370 120
1000 1.25 1.12 12.9 57 100 100 E1.3 Ni1Mo0.5W0.5, 3 wt % Lap TC1.3
370 120 1000 0.9 1.22 1.9 cnbd 115 cnbd C1.3 Ni1Mo0.5W0.5 TC1.3 370
120 1000 0.9 1.12 2.3 cnbd 100 cnbd E1.4 Ni1Mo0.5W0.5, 3 wt % Lap
TC1.4 370 120 1000 1 1.22 2.7 6 128 110 C1.4 Ni1Mo0.5W0.5 TC1.4 370
120 1000 1 1.12 3.9 11 100 100 ULSD E1.5 Ni1Mo0.5W0.5, 3 wt % Lap
TC2.1 320 45 300 2 1.27 0.7 0.3 167 103 C1.5 Ni1Mo0.5W0.5 TC2.1 320
45 300 2 1.20 2.2 0.4 100 100 E1.6 Ni1Mo0.5W0.5, 3 wt % Lap TC2.2
320 45 300 2.25 1.27 3.2 0.4 156 104 C1.6 Ni1Mo0.5W0.5 TC2.2 320 45
300 2.25 1.20 8.6 0.5 100 100 Cnbd = Could not be determined.
Example E2
Ni1W1+3w % Laponite
[0201] 1.8 g laponite (LOI=11.2%, Laponite RD available from
Rockwool Additives Limited) was suspended in water in a separate
stirred vessel for approximately one hour. 50.0 g of tungstic acid
H.sub.2WO.sub.4 (0.2 mole W) was slurried in one liter of water
together with 23.5 g of nickel hydroxycarbonate
2NiCO.sub.3*3Ni(OH).sub.2*4H.sub.2O (0.2 mole of Ni). Then the
laponite suspension was added and the mixture was stirred until the
slurry became homogeneous. The suspension was heated to 95.degree.
C. and held at that temperature for a period of 24 hours
(overnight) with continuous stirring. At the end of this time, the
suspension was filtered. The resulting solid was dried at
120.degree. C. for 16 hours (overnight). The resulting solid was
pelleted; the pellets were crushed and 40-60 mesh fraction was
isolated by sieving. The material was then calcined at 300.degree.
C. for 1 hour. The material was then sulfided and tested as
described below in Test Procedure 3.
Example E3
Ni1Mo0.5W0.5+3w % Laponite
[0202] The same catalyst as Example 1 was sulfided and tested as
described below in Test Procedure 3.
Comparative Experiment C2
Ni1Mo0.5W0.5 No Laponite
[0203] The same catalyst as Comparative 1 was sulfided and tested
as described below in Test Procedure 3.
Comparative Experiment C3
Ni1W1 No Laponite
[0204] A catalyst was prepared as described in Example E2, however
without the addition of laponite suspension. The catalyst was
sulfided and tested as described below in Test Procedure 3.
Comparative Experiment C4
Ni1W1 No Laponite-150.degree. C.
[0205] A catalyst was prepared in a procedure similar to that of
Comparative example C3, except the reaction was carried out at
150.degree. C. in an autoclave heated with microwave radiation,
under autogenic pressure for about 6 hours, instead of 95.degree.
C. under atmospheric pressure in an open vessel for 24 hours. 2.35
g of Ni carbonate (0.02 moles Ni) was added to 100 cc of water
along with 4.99 grams of tungstic acid (0.02 mole W). The
suspension was put into a sealed Weflon.TM. vessel of 275 cc total
volume and heated with microwave radiation at 10.degree. C./min to
150.degree. C. and held under autogenic pressure at that
temperature for 6 hours with continuous stirring. The sample was
cooled to room temperature and the solid filtered and dried
overnight at 120.degree. C. The obtained material was pelleted, the
pellets were crushed and a 40-60 mesh fraction was isolated by
sieving. The material was then calcined at 300.degree. C. for 1
hour. The material was then sulfided and tested using Test
Procedure 3.
Comparative Experiment C5
Ni1W1 No Laponite-90.degree. C., 7 Days
[0206] A catalyst was prepared in a procedure similar to that of
Comparative example C3, except the reaction was carried out at
90.degree. C. in an open vessel for 7 days.
[0207] 50.0 g of tungstic acid H.sub.2WO.sub.4 (0.2 mole W) was
slurried in one liter of water together with 23.5 g of nickel
hydroxycarbonate 2NiCO.sub.3*3Ni(OH).sub.2*4 H.sub.2O (0.2 mole of
Ni). The suspension of the 2, solids was heated to 90.degree. C.
and held at that temperature for a period of 7 days with continuous
stirring. At the end of this time, the suspension was filtered. The
resulting solid was dried at 120.degree. C. for 16 hours
(overnight). The resulting solid was pelleted, the pellets were
crushed and a 40-60 mesh fraction was isolated by sieving. The
material was then calcined at 300.degree. C. for 1 hour. The
material was then sulfided and tested using Test Procedure.
Test Procedure 3: Diesel
[0208] The catalysts E2, E3 and C2 to C5 were tested in a diesel
hydrotreatment process in a down-flow tubular reactor. Each reactor
tube contained 10 ml of catalyst mixed with an equal amount of SiC
particles and sandwiched between layers of SIC particles. Before
being tested the catalysts were presulfided via liquid phase
presulfiding using the feed described in Table 4, which had been
spiked with dimethyl disulfide to a total sulfur content of 3.7 wt.
%. The presulfided catalysts were then tested in the hydrotreatment
of a diesel feedstock having the properties shown in Table 4.
TABLE-US-00005 TABLE 4 GAS OIL FEEDSTOCK S (wt. %) 1.1969 N (ppm
wt) 102 total aromatics (wt. %) 28.3 mono-aromatics (wt. %) 16.5
di-aromatics (wt. %) 11.0 tri+-aromatics (wt. %) 0.8 SIMULATED
DISTILLATION ASTM-D 86 Initial boiling point 178.4.degree. C..sup.
5 vol. % 211.degree. C. 10 vol. % 224.degree. C. 30 vol. %
261.degree. C. 50 vol. % 283.degree. C. 70 vol. % 309.degree. C. 90
vol. % 348.degree. C. Final boiling point 372.degree. C.
[0209] The catalysts were tested under the two conditions shown in
Table 5. The test results are given in Table 6, wherein suffix 1
and 2 after HDS, HDN, N and S refer to Conditions 1 and 2 given in
Table 5.
TABLE-US-00006 TABLE 5 Presulfiding Condition 1 Condition 2
Temperature (.degree. C.) 320 320 340 Pressure (bar) 45 45 20
H.sub.2 to oil ratio (Nl/l) 200 300 300 LHSV (1/h) 3.00 3.00
1.50
[0210] The results presented in Table 6 show that nanosized clays
allows the preparation of catalysts with superior hydrotreating
performances relative to catalysts prepared without nanosized
clays, even when long reaction times or hydrothermal conditions are
used in the absence of nanosized days.
TABLE-US-00007 TABLE 6 CBD S1 S2 N1 N2 RVA RVA RVA RVA SAMPLE
COMPOSITION TEST loaded ppm pmm ppm ppm HDS1 HDS2 HDN1 HDN2 E2
Ni1W1 + 3 w % laponite TC3 1.53 0.7 0.8 0.3 13 403 155 110 139 E3
Ni1Mo0.5W0.5 + 3 w % laponite TC3 1.27 7.7 2 0.4 3.8 140 104 106
105 C2 Ni1.5Mo0.5W0.5 TC3 1.25 15.7 2.2 0.5 4.4 100 100 100 100 C3
Ni1W1-95.degree. C./1 day TC3 1.12 159 20.6 27 29 26 36 25 38 C4
Ni1W1-150.degree. C. TC3 1.72 0.9 0.9 0.3 1.4 347 151 110 130 C5
Ni1W1-90.degree. C./7 days TC3 1.51 6.7 1.7 0.3 2.9 148 112 105
102
Example E4
Ni1W1+10 wt. % Lapointe
[0211] 7.3 g laponite (LOI=11.2%, Laponite RD available from
Rockwool Additives Limited) was suspended in one liter of water in
an open stirred vessel for approximately one hour. As mentioned in
Example E1, the laponite used in this example is formed of primary
particles that are disc-like platelets of about 0.92 nm thickness
and having a lateral dimension of about 25 nm. According to the
manufacturer the laponite has a surface area of over 900
m.sup.2g.sup.-1. 49.9 g of tungstic acid H.sub.2WO.sub.4 (92.7 wt.
% WO.sub.3, 0.2 mole W) and 23.5 g of nickel hydroxycarbonate
2NiCO.sub.3*3Ni(OH).sub.2*4 H.sub.2O (0.2 mole of Ni) were added to
the laponite suspension while stirring. The mixture was stirred
until the slurry became homogeneous. The suspension was heated to
90.degree. C. and held at that temperature for a period of 20
hours, while stirring. The pH of the suspension measured 5.7. At
the end of this time, the suspension was filtered. The resulting
solid was dried at 90.degree. C. overnight. X-ray diffraction of
the resulting solid showed the typical features of the catalyst
according to the invention, as shown in the top XRD pattern of FIG.
2.
Comparative Example C6
Ni1W1+10 wt. % Actigel 208
[0212] The procedure of Example E4 was repeated, except Actigel 208
was used instead of laponite. Actigel 208 is a high quality,
purified, self-dispersing natural clay having rod-shaped particles
that average a thickness of about 3 nm and a lateral dimension of
about 2 microns. The X-ray pattern of the resulting solid is shown
in the bottom XRD pattern of FIG. 2 and shows peaks characteristic
of unreacted metal species rather than the characteristic pattern
of the desired bulk metal particles.
* * * * *