FPII-0389-00
DESCRIPTION
Title of Invention:
METHOD OF PRODUCING REGENERATED HYDROTREATING
CATALYST AND METHOD OF PRODUCING PETROLEUM
PRODUCTS
Technical Field
[0001] The present invention relates to a method of producing a
regenerated hydro treating catalyst, and a method of producing a
petroleum product.
Background Art
[0002] Sulfur-containing compounds, nitrogen-containing compounds,
oxygen-containing compounds, and the like are contained in crude oil as
impurities, and these impurities are also contained in petroleum
fractions obtained by fractionating the crude oil. For the above
impurities in these petroleum fractions, reducing their content is
performed by the step of contacting with a catalyst having hydrotreating
activity in the presence of hydrogen, called hydrotreating. Particularly,
desulfurization in which the content of sulfur-containing compounds is
reduced is well known. Recently, in terms of the reduction of
environmental loads, a demand for the restriction and reduction of the
content of the above impurities, including sulfur-containing compounds,
in petroleum products, has become stricter, and many so-called
"sulfur-free" petroleum products have been produced.
[0003] When a hydrotreating catalyst used for the hydrotreatment of
petroleum fractions described above is used for a certain period, activity
decreases due to the deposition of coke and sulfur components, and the
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like, and therefore, replacement is performed. Particularly, the above
"sulfur-free" is required, and high hydrotreating ability is required in
facilities for the hydrotreatment of fractions, such as kerosene, light oil,
and reduced pressure light oil. As a result, catalyst replacement
5 frequency increases, which, as a result, leads to an increase in catalyst
cost and an increase in the amount of the catalyst discarded.
[0004] As measures for this, the use of a regenerated catalyst for which
a spent hydrotreating catalyst is regenerated (regenerated hydrotreating
catalyst) is partly performed in these facilities (for example, see Patent
10 Literatures 1 and 2).
Citation List
Patent Literature
[0005] Patent Literature 1: Japanese Patent Application Laid-Open No.
52-68890
15 Patent Literature 2: Japanese Patent Application Laid-Open No.
5-123586
Summary of Invention
Technical Problem
[0006] In conventional regeneration treatment, it has been general to
20 select regeneration treatment conditions in terms of whether deposits of
coke can be removed or not, assuming that the main cause of a decrease
in activity occurring during the use of a hydrotreating catalyst lies in the
deposition of coke. For example, in conventional regeneration
treatment, there has been a thought that it is good to set treatment
25 temperature to a temperature as high as possible and set treatment
temperature to a time as long as possible.
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[0007] But, apart from the problem of the removal of deposited coke,
regeneration treatment itself may decrease catalytic activity by changing
the structure of an active metal supported on a catalyst (the coordination
form of the active metal and an oxygen atom, and the like), and the like.
5 In other words, a problem of excessive regeneration treatment is that a
hydrotreating catalyst is damaged, and activity that the hydrotreating
catalyst intrinsically has is decreased.
[0008] It is an object of the present invention to provide a method of
producing a regenerated hydrotreating catalyst in which a regenerated
10 hydrotreating catalyst stably having high activity can be produced from
a spent hydrotreating catalyst by such regeneration treatment conditions
that the hydrotreating catalyst can be sufficiently regenerated, and
excessive regeneration treatment is not provided. In addition, it is an
object of the present invention to provide a method of producing a
15 petroleum product using a regenerated hydrotreating catalyst produced
by the above production method.
Solution to Problem
[0009] The present invention provides a method of producing a
regenerated hydrotreating catalyst, comprising a first step of preparing a
20 hydrotreating catalyst that has been used for hydrotreatment of a
petroleum fraction and has a metal element selected from Group 6
elements of the periodic table; a second step of performing regeneration
treatment for part of the above catalyst prepared in the above first step,
then performing X-ray absorption fine structure analysis for the above
25 catalyst after the regeneration treatment, and obtaining regeneration
treatment conditions in which a ratio IslIo of a peak intensity Is of a
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peak attributed to a bond between the above metal element and a sulfur
atom to a peak intensity 10 of a peak attributed to a bond between the
above metal element and an oxygen atom is in the range of 0.1 to 0.3 in
a radial distribution curve obtained from an extended X-ray absorption
fine structure spectrum; and a third step of performing regeneration
treatment under regeneration treatment conditions determined based on
the above second step, for the other part of the above catalyst prepared
in the above first step.
[0010] In such a production method, the regeneration treatment
conditions determined based on the second step are regeneration
treatment conditions in which the hydrotreating catalyst can be
sufficiently regenerated, and excessive regeneration treatment is not
provided. Therefore, a regenerated hydrotreating catalyst regenerated
in the third step is a regenerated hydrotreating catalyst stably having
high activity.
[0011] In addition, conventionally, for regeneration treatment
conditions, it has been general to select regeneration treatment
conditions in terms of whether deposits of coke can be removed or not,
whereas in the present invention, regeneration treatment conditions are
selected based on the ratio IsfIo in terms of removing the deposition of
sulfur. Therefore, in the production method of the present invention,
providing excessive regeneration treatment is more reliably prevented
compared with conventional methods. In addition, a regenerated
hydrotreating catalyst produced by the production method ofthe present
invention has the same level of activity as a hydrotreating catalyst
before being used for hydrotreating, and therefore can be preferably
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used as a catalyst for obtaining a "sulfur-free" product.
[0012] In the present invention, it is preferred that the above metal
element is molybdenum or tungsten.
[0013] The present invention also provides a method of producing a
5 petroleum product, comprising a step of performing hydrotreatment of a
petroleum fraction using a regenerated hydrotreating catalyst produced
by the production method of the present invention described above.
Such a production method is excellent in economy because a
regenerated hydrotreating catalyst is used.
10 Advantageous Effects of Invention
[0014] According to the present invention, there is provided a method
of producing a regenerated hydrotreating catalyst in which a regenerated
hydrotreating catalyst stably having high activity can be produced from
a spent hydrotreating catalyst by such regeneration treatment conditions
15 that the hydrotreating catalyst can be sufficiently regenerated, and
excessive regeneration treatment is not provided. In addition, there is
provided a method of producing a petroleum product using a
regenerated hydrotreating catalyst produced by the above production
method.
20 Brief Description of Drawings
[0015] [Figure 1] Figure 1 is a diagram showing changes in radial
distribution curves over time in Example 1.
[Figure 2] Figure 2 is a diagram showing a relationship between
a ratio 1sfIo and treatment time in Example 1.
25 [Figure 3] Figure 3 is a diagram showing a relationship between
treatment temperature and minimum required treatment time in
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Example 2.
Description of Embodiments
[0016] A preferred embodiment of the present invention will be
described in detail below.
5 [0017] (Hydrotreating Catalyst)
In this embodiment, a hydrotreating catalyst has a metal element
selected from the Group 6 elements of the periodic table (hereinafter
sometimes referred to as a "metal element M"). Here, examples of the
metal element selected from the Group 6 elements of the periodic table
10 include chromium (Cr), molybdenum (Mo), and tungsten (W). Here,
the periodic table refers to a long-form periodic table defined by the
International Union of Pure and Applied Chemistry (IUPAC). The
hydrotreating catalyst preferably has molybdenum or tungsten, more
preferably molybdenum, as the metal element selected from the Group 6
15 elements of the periodic table.
[0018] Examples of the hydrotreating catalyst include a catalyst having
an inorganic support and a metal element selected from the Group 6
elements of the periodic table, supported on the inorganic support.
[0019] In the hydrotreating catalyst, the amount of the supported metal
20 element selected from the Group 6 elements of the periodic table is
preferably 5 to 40% by mass, more preferably 10 to 30% by mass, in
terms of an oxide of the metal element, based on the total mass of the
hydrotreating catalyst.
[0020] As the inorganic support, an inorganic support comprising
25 aluminum oxide is preferred. Examples of such an inorganic support
include alumina, alumina-silica, alumina-boria, alumina-titania,
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alumina-zirconia, alumina-magnesia, alumina-silica-zirconia, and
alumina-silica-titania. In addition, supports in which porous inorganic
compounds, such as various clay minerals (various zeolites, sepiolites,
montmorillonites, and the like), are added to alumina can also be used.
5 Among these, alumina is preferred as the inorganic support.
[0021] Other than the metal element selected from the Group 6
elements of the periodic table, one or two or more metal elements
selected from the Group 8 to 10 elements of the periodic table may be
further supported on the inorganic support. Examples of the metal
10 element selected from the Group 8 to 10 elements of the periodic table
include iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium
(Rh), iridium (Ir), nickel (Ni), palladium (Pd), and platinum (Pt).
Among these, it is preferred to comprise a metal element selected from
iron, cobalt, and nickel, it is more preferred to comprise a metal element
15 selected from cobalt and nickel, and it is further preferred to comprise
cobalt. In this embodiment, as the combination of metal elements
supported on the inorganic support, cobalt-molybdenum,
nickel-molybdenum, cobalt-molybdenum-nickel,
cobalt-tungsten-nickel, and the like are preferably used.
20 [0022] The amount of the supported metal element selected from the
Group 8 to 10 elements of the periodic table is preferably 0.1 to 20% by
mass, more preferably 0.5 to 10% by mass, in terms of an oxide of the
metal element, based on the total mass ofthe hydrotreating catalyst.
[0023] Examples of the hydrotreating catalyst that is unused (unused
25 catalyst) include a catalyst obtained by supporting 5 to 40% by mass of
a metal element selected from the Group 6 elements of the periodic
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table, as an oxide, and 0.1 to 20% by mass of a metal element selected
from the Group 8 to 10 elements of the periodic table, as an oxide, on an
inorganic support.
[0024] As a precursor of the metal element used when supported on the
5 inorganic support, for example, inorganic salts and organometallic
compounds of the metal element are used. Among these,
water-soluble inorganic salts are preferred. The support of the metal
element is preferably performed using a solution (preferably an aqueous
solution) of the above precursor. As support operation, known
10 methods, for example, an immersion method, an impregnation method,
and a co precipitation method, are preferably used.
[0025] It is preferred that the support on which the metal element is
supported is dried, and then preferably calcined in the presence of
oxygen, and the metal element is turned into an oxide once. Further, it
15 is preferred that before the hydrotreatment of a petroleum fraction is
performed, the metal element is turned into a sulfide by sulfurization
treatment called presulfiding.
[0026] (Hydrotreating step)
In the step of hydrotreating a petroleum fraction, it is preferred
20 to perform the presulfiding of a catalyst charged into a hydrotreating
facility, before a hydrotreating reaction, to turn a metal element in the
catalyst into a metal sulfide.
[0027] The conditions of the presulfiding are not particularly limited,
and it is preferred to add a sulfur compound to feed oil used in the
25 hydrotreatment of a petroleum fraction and continuously contact the
mixture with the catalyst under the conditions of a temperature of 200 to
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380°C, an LHSV (Liquid Hourly Space Velocity) of 1 to 2 h- I, the same
pressure as during hydrotreating operation, and a treatment time of 48
hours or more. The sulfur compound added to the feed oil is not
limited, and dimethyl disulfide (DrvIDS), hydrogen sulfide, and the like
5 are preferred, and it is preferred to add about 1% by mass of these,
based on the mass ofthe feed oil, to the feed oil.
[0028] Operation conditions in the step of hydrotreating a petroleum
fraction are not particularly limited, and for the purpose of maintaining
a state in which the metal element of the catalyst is a sulfide, a small
10 amount of a sulfur compound, such as DMDS, may be added to the feed
oil, but it is preferable that the sulfur compound is not particularly
added because generally, the state in which the metal element of the
catalyst is a sulfide can be maintained by the sulfur compound already
contained in the feed oil.
15 [0029] Hydrogen partial pressure at a reactor inlet in the hydrotreating
step is preferably 3 to 13 :MIla, more preferably 3.5 to 12 :MIla, and
further preferably 4 to 11 :MIla. When the hydrogen partial pressure is
less than 3 :MIla, coke production on the catalyst becomes intense, and
there is a tendency that catalyst life shortens. On the other hand, when
20 the hydrogen partial pressure is more than 13 :MIla, the construction cost
of the reactor, peripheral equipment, and the like increases, and there is
a fear that economy is lost.
[0030] LHSV in the hydrotreating step can be performed in the range of
preferably 0.05 to 5 h-I, more preferably 0.1 to 4.5 h-I, and further
25 preferably 0.2 to 4 h-I. When the LHSV is less than 0.05 hoi, the
construction cost of the reactor becomes excessive, and there is a fear
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that economy is lost. On the other hand, when the LHSV is more than
5 h-I
, there is a fear that the hydrotreatment of the feed oil is not
sufficiently achieved.
[0031] Hydrotreating reaction temperature in the hydrotreating step is
preferably 200°C to 410°C, more preferably 220°C to 400°C, and
further preferably 250°C to 395°C. When the reaction temperature is
less than 200°C, there is a tendency that the hydrotreatment of the feed
oil is not sufficiently achieved. On the other hand, when the reaction
temperature is more than 410°C, the generation of gas components that
are by-products increases, and therefore, the yield oftargeted refined oil
decreases, which is not desired.
[0032] A hydrogen/oil ratio in the hydrotreating step can be effected in
the range of preferably 100 to 8000 SCF/BBL (17 to 1400 NL/L), more
preferably 120 to 7000 SCF/BBL (20 to 1200 NL/L), and further
preferably 150 to 6000 SCF/BBL (25 to 1050 NL/L). When the
hydrogen/oil ratio is less than 100 SCF/BBL (17 NL/L), coke
production on the catalyst at a reactor outlet proceeds, and there is a
tendency that catalyst life shortens. On the other hand, when the
hydrogen/oil ratio is more than 8000 SCF/BBL (1400 NL/L), the
construction cost of a recycle compressor becomes excessive, and there
is a fear that economy is lost.
[0033] A reaction form in the hydrotreating step is not particularly
limited, and can be selected from various processes, such as a fixed bed
and a moving bed, and a fixed bed is preferred. In addition, it is
preferred that the reactor is in the tower type reactor.
[0034] As the feed oil subjected to the hydrotreatment of a petroleum
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fraction, one in which distillation temperature in a distillation test is
preferably in the range of 130 to 700°C, further preferably 140 to
680°C, and particularly preferably 150 to 660°C is used. When feed
oil in which the distillation temperature is less than 130°C is used, a
hydrotreating reaction is a reaction in a gas phase, and there is a
tendency that performance is not sufficiently exhibited with the above
catalyst. On the other hand, when feed oil in which the distillation
temperature is more than 700°C is used, the content of poisoning
substances for the catalyst, such as heavy metals, contained in the feed
oil, increases, and the life of the catalyst may decrease largely. Other
properties of the petroleum fraction used as the feed oil are not
particularly limited, and as typical properties, density at 15°C is 0.8200
to 0.9700 g/cm3
, and sulfur content is 1.0 to 4.0% by mass.
[0035] Here, the sulfur content means sulfur content measured
according to "Energy-dispersive X-ray fluorescence method" in "Crude
oil and petroleum products - Determination of sulfur content" defined in
ns K 2541. In addition, the distillation test means one performed
according to "Determination of distillation characteristics at reduced
pressures" or "Determination of distillation characteristics by gas
chromatography" in "Petroleum products - Determination of distillation
characteristics" defined in ns K 2254. The density at 15°C means
density measured according to "Oscillating Determination of density" in
"Crude petroleum and petroleum products - Determination of density
and Petroleum measurement tables" defmed in ns K2249.
[0036] (Method ofProducing Regenerated Hydrotreating Catalyst)
A method of producing a regenerated hydrotreating catalyst
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according to this embodiment comprises the frrst step of preparing a
hydrotreating catalyst that has been used for the hydrotreatment of a
petroleum fraction and has a metal element selected from the Group 6
elements ofthe periodic table (hereinafter a "spent catalyst"); the second
step of performing regeneration treatment for part of the catalyst
prepared in the first step, then performing X-ray absorption fine
structure analysis for the catalyst after the regeneration treatment, and
obtaining regeneration treatment conditions in which the ratio Is/lo of
the peak intensity Is of a peak attributed to a bond between the above
metal element and a sulfur atom to the peak intensity 10 of a peak
attributed to a bond between the above metal element and an oxygen
atom is in the range of 0.1 to 0.3 in a radial distribution curve obtained
from an extended X-ray absorption fme structure spectrum; and the
third step of performing regeneration treatment under regeneration
treatment conditions determined based on the second step, for the other
part ofthe catalyst prepared in the first step.
[0037] In this embodiment, the regeneration treatment conditions
determined based on the second step are regeneration treatment
conditions in which the hydrotreating catalyst can be sufficiently
regenerated, and excessive regeneration treatment is not provided.
Therefore, a regenerated hydrotreating catalyst regenerated in the third
step is a regenerated hydrotreating catalyst stably having high activity.
[0038] In addition, conventionally, for regeneration treatment
conditions, it has been general to select regeneration treatment
conditions in terms of whether deposits of coke can be removed or not,
whereas in the present invention, regeneration treatment conditions are
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selected based on the ratio IsfIo in terms of removing the deposition of
sulfur. Therefore, in the production method of the present invention,
providing excessive regeneration treatment is more reliably prevented
compared with conventional methods. In addition, a regenerated
hydrotreating catalyst produced by the production method of the present
invention has the same level of activity as a hydrotreating catalyst
before being used for hydrotreating, and therefore can be preferably
used as a catalyst for obtaining a "sulfur-free" product.
[0039] The X-ray absorption fine structure (XAFS) analysis in the
second step is a method in which a substance to be analyzed is
irradiated with X-rays contained in synchrotron radiation generated by
an electron accelerator, or X-rays corresponding to the X-rays, with
energy changed, and the structure of the substance is analyzed by an
absorption spectrum (XAFS spectrum) in which the X-ray absorptivity
of the substance is plotted on the X-ray energy. The extended X-ray
absorption fine structure (EXAFS, spectrum is a spectrum in a region on
a higher energy side than a region in which the X-ray absorptivity
changes suddenly with respect to the irradiation X-ray energy
(absorption edge), in the XAFS spectrum. By Fourier transforming
this EXAFS spectrum, a radial distribution curve can be obtained.
[0040] From the radial distribution curve obtained in this manner,
information regarding a structure around an atom to be measured can be
obtained. In this embodiment, attention is paid to a peak attributed to a
bond between the metal element selected from the Group 6 elements of
the periodic table and an oxygen atom, and a peak attributed to a bond
between the metal element selected from the Group 6 elements of the
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periodic table and a sulfur atom, in the radial distribution curve, and the
peak intensities 10 and Is ofthese peaks are obtained.
[0041] In this embodiment, the above ratio IsfIo needs to be in the range
of 0.1 to 0.3, and is more preferably in the range of 0.1 to 0.2, further
5 preferably 0.1 to 0.15. When the ratio IsfIo is in the above range, an
obtained regeneration treatment catalyst has higher activity.
[0042] When the metal element selected from the Group 6 elements of
the periodic table is molybdenum, the XAFS analysis in the present
invention can be carried out by the following method.
10 X-ray source: continuous X-rays
Analyzing crystal: Si(311)
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Beam size: 1mm x 2 mm
Detector: ionization chamber
Measurement atmosphere: the air
Dwell time: 1 sec
Measurement range: Mo K absorption edge (19500 to 21200
eV)
Data analysis (Fourier transform) program: REX2000
(manufactured by Rigaku)
[0043] In addition, for the details of data analysis, such as the way of
taking a baseline when extracting an EXAFS spectrum, data analysis
can be performed according to a method described in "X-Ray
Absorption Spectroscopy - XAFS and Its Applications - edited by
Toshiaki Ohta, published by Industrial Publishing & Consulting, Inc.
(2002), pp. 57 to 61" using the XAFS analysis integrated software
REX2000 (manufactured by Rigaku). This method was also used in
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Examples described later.
[0044] When the metal element selected from the Group 6 elements of
the periodic table is tungsten, the XAFS analysis in the present
invention can be carried out by the following method.
X-ray source: continuous X-rays
Analyzing crystal: Si(311)
Beam size: 1mm x 2 mm
Detector: ionization chamber
Measurement atmosphere: the air
Dwell time: 1 sec
Measurement range: W L3 absorption edge (9700 to 101400 eV)
Data analysis (Fourier transform) program: REX2000
(manufactured by Rigaku)
[0045] The details of data analysis, such as the way oftaking a baseline
when extracting an EXAFS spectrum, are similar to the above.
[0046] When the metal element selected from the Group 6 elements of
the periodic table is chromium, the XAFS analysis in the present
invention can be carried out by the following method.
X-ray source: continuous X-rays
Analyzing crystal: Si(lll)
Beam size: 1mm x 2 mm
Detector: ionization chamber
Measurement atmosphere: the air
Dwell time: 1 sec
Measurement range: Cr K absorption edge (5500 to 7200 eV)
Data analysis (Fourier transform) program: REX2000
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(manufactured by Rigaku)
[0047] The details of data analysis, such as the way of taking a baseline
when extracting an EXAFS spectrum, are similar to the above.
[0048] When the hydrotreating catalyst has two or more metal elements
5 selected from the Group 6 elements of the periodic table, the second
step is carried out for a metal element in which content in terms of an
oxide is highest, among the metal elements.
[0049] The position of a peak attributed to a bond between each metal
element and an oxygen atom or a sulfur atom can be easily determined
10 by those skilled in the art, and for example, when the metal element
selected from the Group 6 elements of the periodic table is
molybdenum, a peak attributed to a bond between molybdenum and an
oxygen atom (hereinafter a "Mo-O bond"), in a radial distribution curve,
is generally at an interatomic distance in the range of 0.1 to 0.15 nm.
15 In addition, a peak attributed to a bond between molybdenum and a
sulfur atom (hereinafter a "Mo-S bond") is generally at an interatomic
distance in the range of 0.18 to 0.22 nm.
[0050] The first to third steps will be described in detail below.
(First Step)
20 In the first step, a spent catalyst is prepared, and part ofthe spent
catalyst prepared in the first step is subjected to the second step, and the
other part is subjected to the third step.
[0051] Here, the spent catalyst does not necessarily indicate only
hydrotreating catalysts that have been simultaneously used for one
25 hydrotreating. The spent catalyst may include a plurality of
hydrotreating catalysts that have been used for similar or analogous
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hydrotreating. For example, it is also possible to subject a
hydrotreating catalyst that has been used for first hydrotreating to the
second step and subject a hydrotreating catalyst that has been used for
second or subsequent hydrotreating to the third step.
[0052] (Second Step)
In the second step, regeneration treatment conditions in which
the above peak intensity ratio IsfIo is in the range of 0.1 to 0.3 are
obtained. A method of obtaining the regeneration treatment conditions
is not limited, and examples thereof include methods described in the
following methods (1), (2), (3), and (4).
[0053] Method (1):
Part of the spent catalyst is divided into a plurality of samples,
and for each sample, regeneration treatment is performed with treatment
temperature changed and regeneration treatment conditions other than
the treatment temperature (treatment time, a treatment atmosphere, and
the like) unchanged. After the regeneration treatment, for each
sample, the ratio IsfIo is obtained, and treatment time in which the ratio
IsfIo is in the range of 0.1 to 0.3 is obtained.
[0054] According to the method (1), treatment temperature required
when regeneration treatment is performed under predetermined
conditions (treatment time, a treatment atmosphere, and the like) can be
obtained. In addition, specifically, the lowest treatment temperature
and the highest treatment temperature when regeneration treatment is
performed under predetermined conditions can be obtained.
[0055] Method (2):
Part of the spent catalyst is divided into a plurality of samples,
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and for each sample, regeneration treatment is performed with treatment
time changed and regeneration treatment conditions other than the
treatment time (treatment temperature, a treatment atmosphere, and the
like) unchanged. After the regeneration treatment, for each sample,
5 the ratio IsfIo is obtained, and treatment temperature at which the ratio
IsfIo is in the range of 0.1 to 0.3 is obtained.
[0056] According to the method (2), treatment time required when
regeneration treatment is performed under predetermined conditions
(treatment temperature, a treatment atmosphere, and the like) can be
10 obtained. In addition, specifically, the shortest treatment time and the
longest treatment time when regeneration treatment is performed under
predetermined conditions can be obtained.
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[0057] Method (3):
Part of the spent catalyst is placed in a measuring apparatus in
which regeneration treatment and X-ray absorption fine structure
analysis can be simultaneously performed, and X-ray absorption fine
structure analysis is performed at predetermined intervals (for example,
every minute) while regeneration treatment is performed. Then, from
the results ofthe X-ray absorption fine structure analysis, changes in the
ratio IsfIo over time are obtained, and treatment time in which the ratio
IsfIo is in the range of 0.1 to 0.3 is obtained.
[0058] According to the method (3), treatment time (minimum
treatment time and maximum treatment time) required when
regeneration treatment is performed under predetermined conditions
(treatment temperature, a treatment atmosphere, and the like) can be
obtained in a short time without performing measurement for a plurality
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of samples as in the method (2).
[0059] Method (4):
Part of the spent catalyst is divided into a plurality of samples,
each sample is placed in a measuring apparatus in which regeneration
5 treatment and X-ray absorption fine structure analysis can be
simultaneously performed, and X-ray absorption fme structure analysis
is performed at predetermined intervals (for example, every minute)
while regeneration treatment is performed with treatment temperature
changed for each sample. Then, from the results of the X-ray
10 absorption fine structure analysis, changes in the ratio Is/lo over time at
each treatment temperature are obtained, and treatment time in which
the ratio IslIo is in the range of 0.1 to 0.3, at each treatment temperature,
is obtained.
[0060] According to the method (4), a relationship between treatment
15 temperature and required treatment time becomes clear, and therefore,
treatment temperature and treatment time can be appropriately
determined based on the relationship.
[0061] The second step can also be performed by methods other than
the above, and regeneration treatment conditions in which the ratio IslIo
20 is in the range of 0.1 to 0.3 can be determined with various conditions in
regeneration treatment changed.
[0062] Under regeneration treatment conditions in which the ratio Is/lo
is larger than 0.3, the spent catalyst cannot be sufficiently regenerated,
and sufficient catalytic activity may not be obtained. In addition,
25 under regeneration treatment conditions in which the ratio IslIo is less
than 0.1, due to excessive regeneration treatment, the metal elements in
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the catalyst form complex metal oxides, aggregation is caused, and the
like, and the activity of an obtained regenerated catalyst may decrease.
In addition, even if such a decrease in the activity of the regenerated
catalyst does not occur, economy is impaired by unrequired
5 regeneration treatment.
[0063] (Third Step)
In the third step, the regeneration treatment of the spent catalyst
is performed under regeneration treatment conditions determined based
on the second step.
10 [0064] Here, the "regeneration treatment conditions determined based
on the second step" do not necessarily mean applying the regeneration
treatment conditions (treatment temperature, treatment time, and the
like) in which the ratio IsfIo is in the range of 0.1 to 0.3 in the second
step as they are.
15 [0065] For example, when a treatment apparatus by which regeneration
treatment is performed in the second step (hereinafter a "treatment
apparatus A") and a treatment apparatus by which regeneration
treatment is performed in the third step (hereinafter a "treatment
apparatus B") are different, a correlation between the treatment
20 apparatus A and the treatment apparatus B is previously obtained, and
regeneration treatment conditions in the third step can be determined
based on the correlation and the regeneration treatment conditions in
which the ratio IsfIo is in the range of 0.1 to 0.3 in the second step.
[0066] For example, when there is a proportional relationship between
25 a treatment time a required when regeneration treatment is performed by
the treatment apparatus A, and a treatment time b required when
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regeneration treatment is performed by the treatment apparatus B,
regeneration treatment conditions in the third step can be determined by
the following method.
[0067] First, a treatment temperature To and a treatment time bo in
which regeneration can be sufficiently performed by the treatment
apparatus B are previously determined. In addition, a treatment time
ao in which the ratio IsfIo is in the range of 0.1 to 0.3 when regeneration
treatment is performed at the treatment temperature To using the
treatment apparatus A is determined.
[0068] Thus, a correlation between the treatment time a in the treatment
apparatus A and the treatment time b in the treatment apparatus B
(proportionality constant (bolao)) can be obtained.
[0069] Here, the second step is performed, and a treatment time al in
which the ratio IsfIo is in the range of 0.1 to 0.3 when regeneration
treatment is performed at a treatment temperature TI using the treatment
apparatus A is obtained.
[0070] Then, regeneration treatment conditions in the third step is
determined based on the treatment time al obtained in the second step,
and the previously obtained correlation (proportionality constant
(bolao)). In other words, in the third step, regeneration treatment can be
performed under the regeneration treatment conditions of the treatment
temperature T1 and the treatment time al x (bolao).
[0071] Of course, when the treatment apparatus A and the treatment
apparatus B are the same treatment apparatus, or the same regeneration
treatment conditions can be applied to the treatment apparatus A and the
treatment apparatus B, the same regeneration treatment conditions as the
21
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regeneration treatment conditions determined in the second step can be
applied in the third step.
[0072] (Regeneration Treatment)
The regeneration treatment in the second step and the third step
5 will be described in detail below. The specific mode of the
regeneration treatment is not particularly limited, and the regeneration
treatment can be performed by known regeneration methods.
[0073] A facility used for the regeneration treatment is not particularly
limited, and it is preferred that the regeneration treatment is performed
10 in a facility different from a facility for the hydrotreatment of a
petroleum fraction. In other words, rather than performing
regeneration treatment in a state in which the reactor of the facility for
the hydrotreatment of a petroleum fraction remains charged with the
catalyst, it is preferred to extract the catalyst from the reactor, transfer
15 the extracted catalyst to a facility for regeneration treatment, and
perform regeneration treatment by the facility.
[0074] A form for performing the regeneration treatment of the spent
catalyst is not limited, and is preferably composed of the step of
removing from the spent catalyst a pulverized catalyst and fillers and
20 the like other than the catalyst by sieving (removal step), the step of
removing oil components attached to the spent catalyst (deoiling step),
and the step of removing coke, sulfur components, and the like
deposited on the spent catalyst (regeneration step), in this order.
[0075] Among these, for the deoiling step, a method of volatilizing oil
25 components by heating the spent catalyst to a temperature of about 200
to 400°C under an atmosphere in which substantially no oxygen is
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present, for example, a nitrogen atmosphere, and the like are preferably
used. In addition, the deoiling step may be performed by a method of
washing oil components with light hydrocarbons, or a method such as
the removal of oil components by steaming.
5 [0076] The treatment atmosphere, treatment temperature, and treatment
time of the regeneration step can be set as follows. However, the
following ,description does not mean that sufficient catalytic activity can
always be provided to the regenerated hydrotreating catalyst when the
treatment atmosphere, the treatment temperature, and the treatment time
10 meet respective requirements. Strictly, the regeneration treatment in
the third step is performed by regeneration treatment conditions
determined based on the second step.
[0077] It is preferred that the treatment atmosphere in the regeneration
step is an atmosphere in which molecular oxygen is present, and for
15 example, the treatment atmosphere is in air, particularly in an air flow.
[0078] In addition, the treatment temperature of the regeneration step is
different according to the use history of the spent catalyst, and the like,
and is preferably selected in the range of 250 to 700°C, more preferably
260 to 550°C, further preferably 280 to 450°C, and further preferably
20 300 to 400°C. A method of removing deposited coke, sulfur
components, and the like by oxidizing is preferably used. When the
treatment temperature is less than the above lower limit temperature,
there is a tendency that the removal of substances that have decreased
catalytic activity, such as coke and sulfur components, does not proceed
25 efficiently, and the like. On the other hand, when the treatment
temperature is more than the above upper limit temperature, the metal
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elements in the catalyst form complex metal oxides, aggregation is
caused, and the like, and the activity of an obtained regenerated
hydrotreating catalyst may decrease.
[0079] The treatment time of the regeneration step is preferably 0.5
5 hours or more, more preferably 2 hours or more, further preferably 2.5
hours or more, and particularly preferably 3 hours or more. When the
treatment time is less than 0.5 hours, there is a tendency that the
removal of substances that have decreased catalytic activity, such as
coke and sulfur components, does not proceed efficiently.
10 [0080] (Regenerated Hydrotreating Catalyst)
A regenerated hydrotreating catalyst produced by the production
method according to this embodiment is produced by such regeneration
treatment conditions that the hydrotreating catalyst can be sufficiently
regenerated, and excessive regeneration treatment is not provided, and
15 therefore, the regenerated hydrotreating catalyst has high activity.
[0081] The activity of a hydrotreating catalyst can be evaluated, for
example, by desulfurization activity. The desulfurization activity is
evaluated by a desulfurization rate constant obtained from sulfur
component content in a petroleum fraction before hydrotreating, and
20 sulfur component content in the petroleum fraction after hydrotreating.
[0082] The efficiency of regeneration treatment can be evaluated by
specific activity (relative activity) SdSo in which the desulfurization rate
constant So of a hydrotreating catalyst before use (unused catalyst) are
compared with the desulfurization rate constant 81 of a regenerated
25 hydrotreating catalyst (regenerated catalyst). The specific activity
81/80 of the regenerated hydrotreating catalyst produced by the
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production method according to this embodiment is preferably 0.80 or
more, more preferably 0.85 or more.
[0083] (Method of Using Regenerated Hydrotreating Catalyst)
Such a regenerated hydrotreating catalyst may be used alone as
a catalyst in the step of hydrotreating a petroleum fraction described
above, or may be used by laminating it on an unused catalyst. When
the regenerated hydrotreating catalyst is used by laminating it on an
unused catalyst, the proportion of the regenerated hydrotreating catalyst
is not particularly limited, and is preferably 80 or more (mass ratio),
more preferably 120 or more (mass ratio), based on 100 of the unused
catalyst in terms of a reduction in the amount of the catalyst discarded,
the ease of separation of the catalyst during catalyst replacement, and
the like. In the use of the regenerated hydrotreating catalyst,
hydrotreating can be performed as in the above hydrotreating step.
[0084] The preferred embodiment of the present invention has been
described above, but the present invention is not limited to the above
embodiment. For example, the present invention can also be referred
to as a method of determining the conditions of the regeneration
treatment of a hydrotreating catalyst, comprising the fIrst step of
preparIng a hydrotreating catalyst that has been used for the
hydrotreatment of a petroleum fraction and has a metal element selected
from the Group 6 elements of the periodic table; the second step of
performing regeneration treatment for the above catalyst prepared in the
fIrst step, then performing X-ray absorption fme structure analysis for
the above catalyst after the regeneration treatment, and obtaining the
conditions of regeneration treatment in which the ratio Is/Io of the peak
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intensity Is of a peak attributed to a bond between the above metal
element and a sulfur atom to the peak intensity 10 of a peak attributed to
a bond between the above metal element and an oxygen atom is in the
range of 0.1 to 0.3 in a radial distribution curve obtained from an
5 extended X-ray absorption fine structure spectrum; and the third step of
determining the conditions of the regeneration treatment of the
hydrotreating catalyst based on conditions obtained in the second step.
[0085] In addition, the present invention can also be referred to as a
method of producing a regenerated hydrotreating catalyst, comprising
10 the step of regenerating a hydrotreating catalyst that has been used for
the hydrotreatment of a petroleum fraction and has a metal element
selected from the Group 6 elements of the periodic table, under
regeneration treatment conditions determined by the above
determination method.
15 [0086] Further, the present invention may be a method of producing a
petroleum product, comprising the step of performing the
hydrotreatment of a petroleum fraction using a regenerated
hydrotreating catalyst produced by the above production method.
According to such a production method, a petroleum product can be
20 produced with good economy.
Examples
[0087] The present invention will be more specifically described below
by Examples, but the present invention is not limited to the Examples.
25 [0088] [Example 1]
(Unused Catalyst and Spent Catalyst)
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A catalyst in which molybdenum and cobalt as active metals
were supported on an alumina support (unused catalyst, the amount of
molybdenum supported (in terms of an oxide): 22.9% by mass, the
amount of cobalt supported (in terms of an oxide): 2.5% by mass) was
5 prepared. Next, part of the above catalyst was used for 2 years in a
facility for the hydrotreatment ofkerosene to obtain a spent catalyst.
[0089] (XAFS Analysis)
For part of the above spent catalyst, an in-situ cell for XAFS
measurement was installed in the XAFS Experimental Station of the
10 Beamline NWI0A of the PF-AR of the High Energy Accelerator
Research Organization in order to simultaneously perform regeneration
treatment and X-ray absorption fine structure analysis, and while
regeneration treatment was performed, XAFS analysis was performed
every minute from the start of the regeneration treatment until after a
15 lapse of30 minutes. From an EXAFS spectrum at a Mo K absorption
edge obtained from the result of each XAFS analysis, a radial
distribution curve was obtained. Changes in the obtained radial
distribution curves over time are shown in Figure 1.
[0090] A peak Is attributed to a Mo-S bond and a peak 10 attributed to a
20 Mo-O bond in the obtained radial distribution curve were obtained, and
a ratio IsfIo was obtained. A relationship between the ratio IsfIo and
treatment time is shown in Figure 2.
[0091] (Regeneration Treatment)
Using part of the above spent catalyst, regeneration treatment
25 was performed under regeneration treatment conditions in which the
above ratio IsfIo was a value shown in Table 1. For obtained
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regenerated catalysts, catalytic activity was evaluated by the following
method.
[0092] (Evaluation of Catalytic Activity)
For each of the unused catalyst and the regenerated catalysts,
5 catalytic activity was evaluated as follows. First, a fixed bed
continuous flow type reaction apparatus was charged with the catalyst,
and the presulfiding of the catalyst was performed. Specifically, to a
kerosene fraction, 1% by mass of DMDS based on the mass of the
fraction was added, and the mixture was continuously fed to the above
10 catalyst for 48 hours. Then, using the above kerosene fraction (to
which DMDS was not added) as feed oil, a hydrotreating reaction was
performed at a hydrogen partial pressure of 3 MPa, an LHSV of 1 h-I
, a
hydrogen/oil ratio of 200 NL/L, and a reaction temperature of 300°C.
A desulfurization rate constant was obtained from sulfur component
15 content in produced oil. In addition, taking the desulfurization rate
constant of the unused catalyst as 1, the specific activity of the
regenerated catalysts was obtained. The results are shown in Table 1.
[0093] [Table 1]
Regeneration treatment
Ratio Is/Io Specific activity
time (min)
Comparative
10 min 1.37 0.75
Example 1-1
Example 1-1 14 min 0.27 0.85
Example 1-2 17 min 0.16 0.89
Example 1-3 30 min 0.12 0.89
Comparative
45 min 0.08 0.78
Example 1-2
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[0094] In the regenerated catalyst of Comparative Example 1-1 in
which regeneration treatment was performed under regeneration
treatment conditions in which the ratio IsfIo was a value larger than 0.3,
the specific activity was low, and sufficient activity was not obtained.
5 In addition, also in the regenerated catalyst of Comparative Example
1-2 in which regeneration treatment was performed under regeneration
treatment conditions in which the ratio IsfIo was a value less than 0.1,
the specific activity was low, and sufficient activity was not obtained.
On the other hand, in Example 1-1, Example 1-2, and Example 1-3 in
10 which regeneration treatment was performed under regeneration
treatment conditions in which the ratio IsfIo was in the range of 0.1 to
OJ, the specific activity was high, and a regenerated catalyst that was
sufficiently regenerated was obtained.
[0095] [Example 2]
15 XAFS analysis as m Example 1 was performed at a
predetermined regeneration treatment temperature T1°C, and a
relationship between a ratio IsfIo and treatment time was obtained.
Then, a fIrst treatment time in which the ratio IsfIo was 0.3 was taken as
a minimum required treatment time al at the regeneration treatment
20 temperature TI.
[0096] Then, XAFS analysis as in Example 1 was performed at a
regeneration treatment temperature T2 °C lower than the above T1 by
100°C (T1 - 100°C), and a relationship between a ratio IsfIo and
treatment time was obtained. Then, a fIrst treatment time in which the
25 ratio IsfIo was 0.3 was taken as a minimum required treatment time a2 at
the regeneration treatment temperature T2. The ratio a2/al of the
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minimum required treatment time a2 to the minimum required treatment
time al was 1.88.
[0097] In addition, XAFS analysis as in Example 1 was performed at a
regeneration treatment temperature T3 °C higher than the above T1 by
100°C (TI + 100°C), and a relationship between a ratio IsfIo and
treatment time was obtained. Then, a frrst treatment time in which the
ratio IsfIo was 0.3 was taken as a minimum required treatment time a3 at
the regeneration treatment temperature T3. The ratio a3/al of the
minimum required treatment time a3 to the minimum required treatment
time al was 0.75.
[0098] A relationship between the treatment temperature and the
minimum required treatment time obtained is shown in Figure 3.
[0099] Here, using a regeneration treatment apparatus different from
the measuring apparatus in which the above measurement was
performed (hereinafter a "regeneration apparatus B"), a treatment time
bi required in regeneration treatment at the regeneration treatment
temperature T1 was previously studied. As a result, it was confirmed
that when the treatment time bI was 2 hours, a regenerated catalyst
having a specific activity of 0.85 was obtained. In other words, the
regeneration apparatus B is an apparatus in which a regenerated catalyst
having high activity can be obtained with a treatment time of 2 hours at
the regeneration treatment temperature T1.
[0100] (Example 2-1)
When a required treatment time b2 at a regeneration treatment
temperature T2 when the regeneration apparatus B was used was
obtained by the following formula (1), b2= 3.76 hours was obtained.
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b2=bi x a2/al (1)
When regeneration treatment was performed at the regeneration
treatment temperature T2 for a treatment time of 3.76 hours using the
regeneration apparatus B, the specific activity of an obtained
5 regenerated catalyst was 0.89, and a regenerated catalyst having high
activity was obtained.
[0101] (Example 2-2)
When a required treatment time b3 at a regeneration treatment
temperature T3 when the regeneration apparatus B was used was
10 obtained by the following formula (2), b3= 1.50 hours was obtained.
b3=bl x a3/al (2)
When regeneration treatment was performed at the regeneration
treatment temperature T3 for a treatment time of 1.50 hours using the
regeneration apparatus B, the specific activity of an obtained
15 regenerated catalyst was 0.88, and a regenerated catalyst having high
activity was obtained.
[0102] From the above, according to the present invention, by obtaining
a relationship between treatment temperature and required treatment
time in regeneration treatment, required treatment time at any treatment
20 temperature can be appropriately obtained.

CLAIMS
[Claim 1]
A method of producing a regenerated hydro treating catalyst,
comprising:
a first step of preparing a hydro treating catalyst that has been
used for hydro treatment of a petroleum fraction and has a metal element
selected from Group 6 elements of the periodic table;
a second step of performing regeneration treatment for part of
the catalyst prepared in the first step, then performing X-ray absorption
fine structure analysis for the catalyst after the regeneration treatment,
and obtaining regeneration treatment conditions in which a ratio Is/Io of
a peak intensity Is of a peak attributed to a bond between the metal
element and a sulfur atom to a peak intensity Io of a peak attributed to a
bond between the metal element and an oxygen atom is in the range of
0.1 to 0.3 in a radial distribution curve obtained from an extended X-ray
absorption fine structure spectrum; and
a third step of performing regeneration treatment under
regeneration treatment conditions determined based on the second step,
for the other part of the catalyst prepared in the first step.
[Claim 2]
The method of producing a regenerated hydro treating catalyst
according to claim 1, wherein the metal element is molybdenum or
tungsten.
[Claim 3]
A method of producing a petroleum product, comprising a step
of performing hydro treatment of a petroleum fraction using a
32
regenerated hydro treating catalyst produced by the production method
according to claim 1 or 2.