TECHNICAL FIELD
The present invention relates to an oil refining method for producing a plurality of
oil products of high added value with a high efficiency, and more particularly, to an oil
refining method for producing a plurality of oil products of high added value that have
different specifications with a high efficiency from a heavy feed oil or a low sulfur oil.
BACKGROUND ART
Technologies of this type known in the prior art include the following
technologies that are capable of efficiently producing oil products and intermediate
products used for producing the same:
(1) A technology for producing thermally cracked gasoline and gas oil by
separating a feed oil into distillate and atmospheric residue through atmospheric distillation,
distilling the atmospheric residue in a vacuum and processing the vacuum residue (VR) in
a coker; and (2) A technology that applies solvent deasphalting (SDA) to the atmospheric
residue and uses deasphalted oil (DAO) thus obtained as a feed for a fluid catalytic
cracking (FCC) process, or applies vacuum distillation (VDU) to the atmospheric residue
and uses vacuum gas oil (VGO) thus obtained as a feed for fluid catalytic cracking (FCC)
process.
However, the technology (1) described above faces the problem that the market
for coker bottom (coke) is pressured by over supply that hinders the construction of cokers
which produce coke as a byproduct.
The technology (2) described above has such a problem as described below.
Fuels for transportation such as gasoline and gas oil can be produced by separating
deasphalted oil and vacuum gas oil from ultra heavy crude that is found in vast amount of
reserves or atmospheric residue of which an over supply is expected in the future, and
processing the deasphalted oil or vacuum gas oil by fluid catalytic cracking (FCC) or
hydrocracking (HCR) process. But this scheme would cause supply-demand imbalance
in the market of fuels for transportation and power generation, since a higher increase in
the demand for electricity over the demand increase for gasoline and gas oil is expected
world over.
Besides the technologies (1) and (2) described above, there is such a technology
of producing gas turbine fuel (GTF) from ultra heavy crude that includes much vanadium
(V) content or from atmospheric residue through solvent deasphalting process. However,
this technology also has the problem that increasing the yield (extraction rate) of producing
the deasphalted oil in the solvent deasphalting process leads to higher contamination of the
deasphalted oil product by metals and/or residual carbon. This results in increased
process load (higher pressure, low LHSV) when refining the deasphalted oil by
demetalization and desulfurization, thus making this method economically
disadvantageous. When the yield of deasphalted oil production is lowered to circumvent
the problem described above, the yield of the gas turbine fuel produced decreases, leading
to the new problem of increased production of asphaltene (pitch) that has lower added
value.
An object of the present invention is to provide a method of refining oil for
producing oil products (for example, gas turbine fuel) that includes a vanadium (V) content
of 0.5 wt ppm or lower and intermediate oil products having metal content (V + Ni) of 30
wt ppm or lower that can be used as the feed for a fluid catalytic cracking (FCC) or a
hydrocracking (HCR) process efficiently at the same time, whether a particularly heavy
feed oil or a feed oil having a low sulfur content is used as the starting material.
DISCLOSURE OF THE INVENTION
A method for refining oil according to the first aspect of the present invention is a
method for producing oil products including a plurality of intermediate oil products by
refining a feed oil, comprising a fractional distillation process for separating the feed oil
into distillate and a residue through distillation; a hydrorefining process wherein at least a
part of the distillate obtained in the fractional distillation process is refined and
desulfurized by hydrogenation in the presence of hydrogen and a catalyst thereby to obtain
a hydrorefined oil; a solvent deasphalting process wherein the residue is deasphalted with a
solvent thereby to obtain deasphalted oil as an extract and asphaltene (pitch) as the residue;
a hydrodemetalizating/desulfurizing process wherein at least a part of the deasphalted oil is
demetalized and desulfurized by hydrogenation in the presence of hydrogen and a catalyst
thereby to obtain HDMS refined oil that has been demetalized and desulfurized; and a first
mixing process wherein a part of the HDMS refined oil and at least a part of the
hydrorefined oil are mixed in order to produce one of the oil products.
According to this refining method, since at least a part of the hydrorefined oil is
mixed with a part of the HDMS refined oil in the first mixing process, it is possible to
obtain an oil product that has a sufficiently low vanadium (V) content such as gas turbine
fuel, and also to produce intermediate oil products having a relatively low metal content (V
+ Ni) that can be used as the feed for fluid catalytic cracking (FCC) or a hydrocracking
(HCR) process from the remainder of the HDMS refined oil.
Since the intermediate oil product used as the feed for a fluid catalytic cracking or
a hydrocracking process has more lenient tolerance for metal contents than gas turbine fuel
or the like does, the yield of deasphalted oil produced in the solvent deasphalting process
can be improved by producing the gas turbine fuel and the feed for a fluid catalytic
cracking or a hydrocracking process at the same time, thereby suppressing the production
of asphaltene (pitch) from the atmospheric residue.
A method for refining oil according to the second aspect of the present invention
comprises a fractional distillation process for separating the feed oil into a distillate and a
residue through distillation; a hydrorefining process wherein at least a part of the distillate
obtained in the fractional distillation process is refined and desulfurized through
hydrogenation in the presence of hydrogen and a catalyst thereby to obtain a hydrorefined
oil; a solvent deasphalting process wherein the residue is deasphalted with a solvent
thereby to obtain deasphalted oil as an extract and asphaltene (pitch) as the residue; a
hydrodemetalizating/desulfurizing process wherein at least a part of the deasphalted oil is
demetalized and desulfurized through hydrogenation in the presence of hydrogen and a
catalyst thereby to obtain HDMS refined oil that has been demetalized and desulfurized; a
vacuum fractional distillation process wherein the HDMS refined oil is distilled in a
vacuum and separated into vacuum gas oil and vacuum residue; and a second mixing
process wherein at least a part of the vacuum gas oil and at least a part of the hydrorefined
oil are mixed thereby to produce one of the oil products.
According to this refining method described above, since at least a part of the
vacuum gas oil and at least a part of the hydrorefined oil are mixed in the second mixing
process, oil products can be obtained that have a sufficiently low vanadium (V) content
such as gas turbine fuel. It is also possible to obtain an intermediate oil product having a
relatively low metal content (V + Ni) that can be used as the feed for a fluid catalytic
cracking or a hydrocracking process from the remainder of vacuum gas oil or the vacuum
residue obtained by vacuum distillation, and even from the HDMS refined oil.
Also because the HDMS refined oil is subjected to a vacuum fractional distillation
process to be separated into vacuum gas oil and vacuum residue having low metal content
and residual carbon content by making use of the range of boiling points of the distillation
properties particularly in the vacuum fractional distillation process, relatively high
concentrations of vanadium and metals can be allowed for the HDMS refined oil, thus
improving the yield of deasphalted oil in the solvent deasphalting process, and therefore it
is possible to suppress the production of asphaltene (pitch) from the atmospheric residue.
A method for refining oil according to the third aspect of the present invention
comprises a fractional distillation process for separating the feed oil into distillate and a
residue through distillation; a hydrorefining process wherein at least a part of the distillate
obtained in the fractional distillation process is refined and desulfurized through
hydrogenation in the presence of hydrogen and a catalyst thereby to obtain a hydrorefined
oil; a vacuum fractional distillation process wherein the residue is distilled in a vacuum and
separated into vacuum gas oil and vacuum residue; a solvent deasphalting process wherein
the vacuum residue is deasphalted with a solvent thereby to obtain deasphalted oil as an
extract and asphaltene (pitch) as the residue; a hydrodemetalizating/desulfurizing process
wherein the vacuum gas oil and deasphalted oil are mixed and the mixture is subjected to
hydrodemetalizating/desulfurizing process in the presence of hydrogen and a catalyst
thereby to obtain HDMS refined oil that is demetalized and desulfurixed; and a third
mixing process wherein a part of the HDMS refined oil and at least a part of the
hydrorefined oil are mixed thereby to produce one of the oil products.
According to this refining method, since a part of the HDMS refined oil and at
least a part of the hydrorefined oil are mixed in the third mixing process, the vanadium (V)
content of the mixed oil thus obtained is decreased sufficiently and it is possible to obtain
an oil product used as gas turbine fuel. It is also possible to obtain an intermediate oil
product having a relatively low metal content (V + Ni) that can be used as the feed for a
fluid catalytic cracking or a hydrocracking process even from the remainder of the HDMS
refined oil obtained by processing the mixture of the vacuum gas oil and deasphalted oil in
the hydrodemetalizating/desulfurizing process.
Since the intermediate oil product used as the feed for a fluid catalytic cracking or
a hydrocracking process has a higher tolerable concentrations of metal contents than those
of gas turbine fuel or the like, the yield of the deasphalted oil in the solvent deasphalting
process can be improved by producing the gas turbine fuel and the feed for a fluid catalytic
cracking or a hydrocracking process at the same time, thereby suppressing the production
of asphaltene (pitch) from the atmospheric residue.
In case the present invention is applied to a heavy oil having an API gravity of 20
or lower, the amount of pitch produced can be made lower than in the prior art, in which a
large quantity of pitch that has a low commodity value generated as a byproduct, and the
yield of producing a plurality of oil products having a high added values is improved, thus
resulting in a greatly improved productivity.
A method for refining oil according to the fourth aspect of the present invention is
a method for producing oil products including a plurality of intermediate oil products by
refining a feed oil that includes low sulfur content, and comprises a fractional distillation
process for separating the feed oil into distillate and a residue through distillation; a solvent
deasphalting process wherein the residue obtained in the fractional distillation process is
deasphalted with a solvent thereby to obtain deasphalted oil as an extract and asphaltene
(pitch) as the residue; a hydrodemetalizating/desulfurizing process wherein at least a part
of the deasphalted oil is demetalized and desulfurized through hydrogenation in the
presence of hydrogen and a catalyst thereby to obtain HDMS refined oil that has been
demetalized and desulfurized; and a fourth mixing process wherein a part of the HDMS
refined oil and at least a part of the distillate are mixed thereby to produce one of the oil
products.
According to this refining method, since a part of the HDMS refined oil and at
least a part of the hydrorefined oil are mixed in the fourth mixing process, it is possible to
obtain an oil product such as gas turbine fuel that has a sufficiently low vanadium (V)
content. It is also possible to obtain an intermediate oil product having low metal content
(V + Ni) that can be used as the feed for a fluid catalytic cracking or a hydrocracking
process from the remainder of the HDMS refined oil.
Since the intermediate oil product used as the feed for a fluid catalytic cracking or
a hydrocracking process has a higher tolerable concentrations of metal contents than that of
gas turbine fuel or the like, the yield of deasphalted oil produced in the solvent
deasphalting process can be improved by producing the gas turbine fuel and the feed for a
fluid catalytic cracking or a hydrocracking process at the same time, thereby suppressing
the production of asphaltene (pitch) from the atmospheric residue.
A oil refining method according to the fifth aspect of the invention comprises a
fractional distillation process for separating the feed oil into distillate and a residue through
distillation; a solvent deasphalting process wherein the residue obtained in the fractional
distillation process is deasphalted with a solvent thereby to obtain deasphalted oil as an
extract and asphaltene (pitch) as the residue; a hydrodemetalizating/desulfurizing process
wherein at least a part of the deasphalted oil is demetalized and desulfurized by
hydrogenation in the presence of hydrogen and a catalyst thereby to obtain HDMS refined
oil that has been demetalized and desulfurized; a vacuum fractional distillation process
wherein the HDMS refined oil is distilled in a vacuum and separated into vacuum gas oil
and vacuum residue; and a fifth mixing process wherein at least a part of the vacuum gas
oil and at least a part of the distillate are mixed in order to produce one of the oil products.
According to this refining method, since at least a part of the vacuum gas oil and
at least a part of the distillate are mixed in the fifth mixing process, it is possible to obtain
an oil product that has a sufficiently low vanadium (V) content such as gas turbine fuel.
It is also possible to produce an intermediate petroleum product, that has relatively low
metal content (V + Ni) and can be used as the feed for a fluid catalytic cracking or a
hydrocracking process, from the remainder of the vacuum gas oil or the vacuum residue
obtained by vacuum distillation process, and even from the HDMS refined oil.
Also, the HDMS refined oil is subjected to vacuum distillation so as to separate
into vacuum gas oil and vacuum residue having low metal content and residual carbon
content by making use of the range of boiling points of the distillation properties
particularly in the vacuum fractional distillation process, thus relatively high
concentrations of vanadium and metals can be allowed for the HDMS refined oil, thereby
improving the yield of deasphalted oil in the solvent deasphalting process, and therefore it
is possible to suppress the production of asphaltene (pitch) from the atmospheric residue.
A oil refining method of the sixth aspect of the present invention comprises a
fractional distillation process for separating the feed oil into distillate and a residue through
distillation; a vacuum fractional distillation process wherein the residue obtained in the
fractional distillation process is distilled in a vacuum and separated into vacuum gas oil
and vacuum residue; a solvent deasphalting process wherein the vacuum residue is
deasphalted with a solvent thereby to obtain deasphalted oil as an extract and asphaltene
(pitch) as the residue; a hydrodemetalizating/desulfurizing process wherein the vacuum gas
oil and the deasphalted oil are mixed and the mixture is demetalized and desulfurized by
hydrogenation in the presence of hydrogen and a catalyst thereby to obtain HDMS refined
oil that has been demetalized and desulfurized; and a sixth mixing process wherein a part
of the HDMS refined oil and at least a part of the distillate are mixed thereby to produce
one of the oil products.
According to this refining method, since a part of the HDMS refined oil and at
least a part of the distillate are mixed in the sixth mixing process, the vanadium (V) content
of the mixed oil becomes sufficiently low and it is possible to obtain an oil product that can
be used as gas turbine fuel. It is also possible to produce an intermediate oil product
having sufficiently low metal content (V + Ni) that can be used as the feed for a fluid
catalytic cracking or a hydrocracking process even from the remainder of HDMS refined
oil that is obtained by processing the mixture of vacuum gas oil and deasphalted oil in the
hydrodemetalizating/desulfurizing process.
Since the intermediate oil product used as the feed for a fluid catalytic cracking or
a hydrocracking process has a higher tolerable concentration of metal contents than that of
gas turbine fuel or the like, the yield of deasphalted oil produced in the solvent
deasphalting process can be improved by producing the gas turbine fuel and the feed for a
fluid catalytic cracking or a hydrocracking process at the same time, thereby suppressing
the production of asphaltene (pitch) from the vacuum residue.
When the method of one of fourth through sixth aspects of the invention is applied
to a crude oil having low sulfur content of 2.0 wt% or lower, the amount of pitch produced
can be made less than in the prior art where a large quantity of pitch that has low
commodity value is produced, thus improving the yield of a plurality of oil products
having a high added values, resulting in greatly improved productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 through Fig. 6 are process flow diagrams explaining the first through sixth
embodiments of the oil refining method according to the present invention.
Fig. 7 through Fig. 12 are process flow diagrams explaining the oil refining
methods of the first through sixth experimental examples.
BEST MODE FOR CARRYING OUT THE INVENTION
Now preferred embodiments of the oil refining method according to the present
invention will be described below with reference to the accompanying drawings. It
should be understood, however, that the present invention is not limited to the
embodiments described below and, for example, any combination of components of these
embodiments is deemed to fall within the scope of the present invention.
Fig. 1 is a process flow diagram explaining an embodiment of the oil refining
method according to the present invention, wherein a heavy crude oil is used as feed oil
from which gas turbine fuel (GTF) and a feed for fluid catalytic cracking (FCC) process or
a feed for hydrocracking (HCR) process are produced at the same time.
There is no limitation to the feed oil to be processed, and any hydrocarbon oil
ranging from crude oil to heavy oil can be used. The description that follows will deal
with cases where the present invention is applied to heavy crude oil such as Orinoco tar,
particularly to heavy oils having an API gravity not higher than 20 while achieving a
remarkable effect of improving the yield of producing a plurality of oil products having a
high added values.
API gravity is an index for classifying crude oils by the physical properties
thereof, and is calculated from the specific gravity by the following formula, where S is the
specific gravity at 60 degrees Fahrenheit.
API = (141.5/S) - 131.5
According to the method of this example where the heavy crude oil described
above is used as the feed oil, the feed oil is first subjected to fractional distillation process
1 to separate into a distillate M1 consisting of low-boiling point oil and a residue M2 of
high boiling point by distilling similarly to the prior art. While a topper, which is a
commonly used atmospheric distillation apparatus, is preferably used as the fractional
distillation apparatus of this example, there is no limitation to the apparatus as long as it is
means for fractional distillation. Distillates may be either collectively recovered without
classifying, or recovered individually after classifying by the boiling point. In case
distillates are recovered in a plurality of classes and some class of the distillate satisfies the
specification requirements for petroleum, the hydrorefining process 2 that would follow
may be omitted or bypassed as indicated by arrow 11.
Then at least a part of the distillate M1 obtained in the fractional distillation
process 1 is introduced into the hydrorefining process (HT process) 2 to be refined and
desulfurized by hydrogenation in the presence of hydrogen and a catalyst, thereby
producing hydrorefined oils M3, M3'.
In the hydrorefining process of the distillate M1, hydrogen gas is mixed with the
distillate M1 and the mixture is introduced into a reactor filled with a CoMo catalyst or a
NiMo catalyst where sulfur and nitrogen contents included in the distillate M1 are removed
by hydrogenation in the presence of hydrogen under a high pressure, followed by the
separation of hydrogen gas in a high-pressure separator thereby to obtain the hydrorefined
oils M3, M3'.
Apart from the hydrorefining process 2, the residue M2 obtained in the fractional
distillation process 1 is introduced into the solvent deasphalting process (SDA process) 3
to be deasphalted with a solvent, thereby to obtain deasphalted oil (DAO) M4 as an extract
and asphaltene (pitch) M5.
In the solvent deasphalting process, the residue M2 is put into contact with the
solvent in counterflow in a solvent extraction tower and is separated into deasphalted oil
and asphaltene (pitch) that includes metals and residual carbon in high concentrations.
The deasphalted oil is recovered together with the solvent through the top of the tower, and
the solvent is separated from the recovered material in super-critical state. Asphaltene
(pitch) is recovered together with the solvent through the bottom of the tower, and the
solvent in the recovered material is removed by evaporation.
It is known that, in solvent deasphalting process in general, the extraction ratio of
deasphalted oil from the feed oil varies among components included in the deasphalted oil
such as sulfur, vanadium, nitrogen and residual carbon. According to the present
invention, in case the residue obtained by fractional distillation of heavy oil is used as the
feed oil, the extraction ratio for the vanadium content included in the deasphalted oil to the
vanadium content included in the feed oil is preferably controlled to within 20% when the
atmosphere distilled residue is used as the feed oil, or within 15% when the vacuum
distilled residue is used as the feed oil. There is not a specific lower limit to the
extraction ratio in either case, and the extraction ratio may be in a range appropriately
selected in accordance to the type of feed oil and the vanadium content. In case the
residue obtained by fractional distillation of low-sulfur feed oil including a sulfur content
of 2.0 wt% or lower is used as the feed oil, the vanadium content included in the
deasphalted oil is preferably controlled to within 25 wt ppm when atmosphere distilled
residue is used as the feed oil, or within 70 wt ppm when vacuum distilled residue is used
as the feed oil.
According to the present invention, refined oil can be produced efficiently with
the extraction ratio in the solvent deasphalting process being maximized, without placing a
significant load on the hydrodemetalizating/desulfurizing process that follows the solvent
deasphalting process, in either of the cases described above.
In case the refining process that follows the solvent deasphalting process 3
includes only the hydrodemetalizating/desulfurizing process 4, it is preferable to control
the extraction rate of the solvent deasphalting process 3 so that the extraction ratio for the
vanadium content included in the deasphalted oil M4 to the vanadium (V) content included
in the residue M2 used as the feed oil is 20% or lower.
At least a part of the deasphalted oil M4 obtained in the solvent deasphalting
process 3 is introduced into the hydrodemetalizating/desulfurizing process (HDMS
process) 4, wherein the deasphalted oil is demetalized and desulfurized by hydrogenation
in the presence of hydrogen and a catalyst thereby to obtain HDMS refined oil that has
been demetalized and desulfurized. The hydrodemetalizating/desulfurizing process is
basically the same as the hydrorefining process 2 described previously, and the description
thereof will be omitted.
The demetalizing and desulfurizing conditions for the HDMS refined oil M6
obtained in the hydrodemetalizating/desulfurizing process are preferably selected so as to
achieve the vanadium (V) content of 2 wt ppm or lower, preferably 1 wt ppm or lower, and
a sulfur content of 0.5 wt % or lower, preferably 0.3 wt % or lower.
Then a part of the HDMS refined oil M6 obtained in the
hydrodemetalizating/desulfurizing process 4 and at least part of the hydrorefined oil M3
obtained in the hydrorefining process 2 are mixed in the first mixing process 5 thereby to
obtain a petroleum product.
In order to produce gas turbine fuel (GTF) as the oil product obtained in the first
mixing process 5, mixing condition is set so as to achieve the vanadium (V) content of 0.5
wt ppm or lower. In this case, when the vanadium content of the HDMS refined oil M6 is
assumed to be 1 wt ppm, for example, rate of the HDMS refined oil M6 to the
hydrorefined oil M3 is set to 1:1 or less (that is, a smaller proportion of the HDMS refined
oil M6) in volume proportion for mixing, with the vanadium content in the hydrorefined
oil M3 being set to 0 wt ppm.
Of the HDMS refined oil M6 obtained in the hydrodemetalizating/desulfurizing
process 4, the remainder that is not subjected to the first mixing process 5 is used as an
intermediate oil product to be used as the feed for the fluid catalytic cracking (FCC)
process or the hydrocracking (HCR) process. Of the hydrorefined oil M3, the remainder
that is not subjected to the first mixing process 5 may be used as oil product M3' such as
naphtha, gasoline, kerosene, or gas oil.
According to the oil refining method described above, since a part of the HDMS
refined oil M6 and at least a part of the hydrorefined oil M3 are mixed, it is possible to
obtain an oil product that has a sufficiently low vanadium (V) content, such as gas turbine
fuel. It is also possible to produce an intermediate oil product having relatively low metal
content (V + Ni) that can be used as the feed for fluid catalytic cracking (FCC) or
hydrocracking (HCR) process, from the remainder of HDMS refined oil M6 and therefore
a plurality of oil products having a high added values can be produced efficiently at the
same time.
Since the intermediate oil product used as the feed for fluid catalytic cracking
(FCC) or hydrocracking (HCR) process has a higher tolerable concentrations of metal
contents than that of gas turbine fuel (GTF) or the like, the yield of deasphalted oil M4
produced in the solvent deasphalting process 3 can be improved without accompanying a
load of hydrodemetalizating/desulfurizing process, thereby suppressing the production of
asphaltene (pitch) M5 from the residue M2.
Now referring to the process flow diagram of Fig. 1, in case the deasphalted oil
M4 obtained in the solvent deasphalting process 3 includes relatively low concentrations of
metals and sulfur, and is mixed with a part of the HDMS refined oil that includes further
lower concentrations of metals and sulfur so that the requirements for the feed stock
properties for fluid catalyst cracking (FCC) or hydrocracking (HCR) process are satisfied,
a part thereof may be sent through the bypass shown by reference numeral 12 in Fig. 1 to
be mixed with a part of the HDMS refined oil M6, instead of being subjected to the
hydrodemetalizating/desulfurizing process 4, thereby to produce intermediate oil products
used as the feed for fluid catalytic cracking (FCC) process or the feed for hydrocracking
(HCR) process.
[Second embodiment]
Fig. 2 is a process flow diagram explaining the second embodiment of the oil
refining method according to the present invention, wherein gas turbine fuel (GTF) and
feed for fluid catalytic cracking (FCC) process or feed for hydrocracking (HCR) process
are produced at the same time from a feed oil, similarly to the first embodiment shown in
Fig. 1.
The second embodiment is different from the first embodiment shown in Fig. 1
mainly in that a vacuum fractional distillation process 6 is provided to follow the
hydrodemetalizating/desulfurizing process 4, so as to process the HDMS refined oil M6
that has been obtained in a vacuum distillation and separate it into vacuum gas oil M7 and
vacuum residue M8 through a vacuum distillation process. In other words, with the oil
refining method shown in Fig. 2, the HDMS refined oil M6 obtained similarly to the
example shown in Fig. 1 is distilled in a vacuum in the vacuum fractional distillation
process 6.
In the vacuum fractional distillation process, the HDMS refined oil M6 is
introduced into a vacuum distillation tower where the HDMS refined oil M6 is distilled
and separated into a low-boiling point component and a high-boiling point component,
while the vacuum gas oil M7 having low boiling point is obtained from the top of the
tower and the vacuum residue M8 having a high boiling point is obtained from the bottom
of the tower.
Since the vacuum fractional distillation process described above is applied,
extraction ratio for the vanadium content included in the deasphalted oil M4 to the
vanadium (V) content included in the residue M2 used as the feed oil is 30% or lower.
This makes it possible to improve the yield of the oil products without applying a large
load of a hydrodemetalizating/desulfurizing process.
The demetalizing and desulfurizing conditions for the HDMS refined oil M6
obtained by hydrodemetalizating/desulfurizing process of the deasphalted oil M4 are
selected so as to control the vanadium (V) content of the HDMS refined oil M6 to 20 wt
ppm or lower, preferably 10 wt ppm or lower, and the sulfur content is desirably controlled
to 0.5 wt % or lower, preferably 0.3 wt % or lower.
Moreover, it is desirable to set the vanadium content of the vacuum gas oil
obtained by vacuum distillation of the HDMS refined oil M6 to 1 wt ppm or lower.
Following the process described above, at least a part of the vacuum gas oil M7
obtained in the vacuum fractional distillation process 6 and at least a part of the
hydrorefined oil M3 obtained in the hydrorefining process 2 are mixed in the second
mixing process 7 thereby to obtain one of the oil products.
In order to produce gas turbine fuel (GTF) as the oil product obtained in the
second mixing process 7, the mixing condition is set so as to achieve the vanadium (V)
content of 0.5 wt ppm or lower similarly to the example shown in Fig. 1. In this case, the
mix proportion is properly adjusted according to the vanadium content of the vacuum gas
oil M7 similarly to the previous example. When vanadium (V) content of the vacuum gas
oil M7 is 0.5 wt ppm or lower, this may be used as gas turbine fuel (GTF) without adding
the hydrorefined oil M3 thereto.
The remainder of the vacuum gas oil M7, the vacuum residue M8 obtained by
vacuum distillation, and remainder of the HDMS refined oil M6 that is not fed to the
vacuum fractional distillation process 6 are used individually or in an appropriate
combination thereof thereby to provide an intermediate oil product used as the feed for
fluid catalytic cracking (FCC) process or the feed for hydrocracking (HCR) process.
With the oil refining method described above, since the HDMS refined oil M6 is
subjected to vacuum distillation and is separated into the vacuum gas oil M7 and the
vacuum residue M8 that include no significant metal content or residual carbon content, by
making use of the range of boiling points of the distillation properties in the vacuum
fractional distillation process 6, relatively high concentrations of vanadium, metals and
residual carbon can be allowed for the HDMS refined oil M6 itself, thus improving the
yield of deasphalted oil M4 in the solvent deasphalting process 3, and therefore it is
possible to suppress the production of asphaltene (pitch) M5 from the residue M2.
With regard to the deasphalted oil M4 obtained in the solvent deasphalting
process 3, too, in case the vanadium (V) content of M4 is sufficiently low, a part of the M4
may be introduced into the bypass 12 to be mixed with a part of the vacuum residue M8
sent from the vacuum fractional distillation process 6, instead of being subjected to the
hydrodemetalizating/desulfurizing process 4, thereby to produce intermediate oil products
used as the feed for fluid catalytic cracking (FCC) or hydrocracking (HCR) process. The
HDMS refined oil M6 obtained in the hydrodemetalizating/desulfurizing process 4 may
also be introduced into the bypass 12 to be mixed with the vacuum residue M8 sent from
the vacuum fractional distillation process 6 thereby to produce intermediate oil products
used as the feed for fluid catalytic cracking (FCC) or hydrocracking (HCR) process.
[Third embodiment]
Fig. 3 is a process flow diagram explaining the third embodiment of the present
invention, wherein gas turbine fuel (GTF) and feed for fluid catalytic cracking (FCC) or
hydrocracking (HCR) process are produced at the same time from a feed oil, similarly to
the example shown in Fig. 1.
The third embodiment is different from the first embodiment shown in Fig. 1
mainly in that fractional distillation process 1 is followed by a vacuum fractional
distillation process 20 wherein the residue M2 is separated into vacuum gas oil M11 and
vacuum residue M12 by vacuum distillation, a solvent deasphalting process 21 wherein the
vacuum residue M12 is separated into deasphalted oil M13 and asphaltene (pitch) M14 by
solvent deasphalting, and a hydrodemetalizating/desulfurizing process 22 wherein a
mixture of the deasphalted oil M13 and the vacuum gas oil M11 is subjected to
hydrodemetalizating/desulfurizing process thereby to produce HDMS refined oil M15.
With the oil refining method shown in Fig. 3, the residue M2 obtained similarly to
the example shown in Fig. 1 is distilled in a vacuum in the vacuum fractional distillation
process 20.
In the vacuum fractional distillation process, the residue M2 is introduced into a
vacuum distillation tower where the residue M2 is distilled and separated into a
low-boiling point component and a high-boiling point component, while the vacuum gas
oil M11 having the lower boiling point is obtained from the top of the tower and the
vacuum residue M12 having the higher boiling point is obtained from the bottom of the
tower.
Following the vacuum fractional distillation process 20, the vacuum residue M12
thus obtained is subjected to the solvent deasphalting process 21 and is separated into
deasphalted oil M13 and asphaltene (pitch) M14. Although the solvent deasphalting
process is similar to those in the examples shown in Fig. 1 and Fig. 2, the desirable upper
limit of the extraction ratio of vanadium for the deasphalted oil M13 obtained from the
vacuum residue by solvent deasphalting process becomes lower in correspondence to the
concentrations of metals, residual carbon and sulfur that are higher than those of the
residue M2, and therefore the extraction ratio is preferably controlled to 15%.
Then the deasphalted oil M13 and the vacuum gas oil M11 thus obtained are
mixed and the mixture is subjected to the hydrodemetalizating/desulfurizing process,
thereby to obtain the HDMS refined oil M15. The demetalizing and desulfurizing
conditions for the HDMS refined oil M15 thus obtained are preferably selected so as to
achieve the vanadium (V) content of 2 wt ppm or lower, preferably 1 wt ppm or lower, and
a sulfur content of 0.5 wt ppm or lower, preferably 0.3 wt ppm or lower.
Then a part of the HDMS refined oil M15 obtained in the
hydrodemetalizating/desulfurizing process 22 and at least a part of the hydrorefined oil M3
obtained in the hydrorefining process 2 are mixed in the third mixing process 23, thereby
to obtain gas turbine fuel (GTF) as one of the oil products that has vanadium (V) content of
0.5 wt ppm or lower.
Of the HDMS refined oil M15 obtained in the hydrodemetalizating/desulfurizing
process 22, the remainder that is not subjected to the third mixing process 23 may be used
as an intermediate oil product to be fed to fluid catalytic cracking (FCC) or hydrocracking
(HCR) process.
In case the deasphalted oil M13 and the vacuum gas oil M11 include significantly
different concentrations of metals, residual carbon and sulfur and require reaction
conditions, particularly partial pressure of hydrogen, that are significantly different from
each other, the M13 and the M11 may be, instead of being mixed, subjected to
hydrodemetalizating/desulfurizing process in separate reactors each under optimum
conditions, and then mixed or at least part of the vacuum gas oil M11 that has been
subjected to hydrodemetalizating/desulfurizing process and at least a part of the
hydrorefined oil M3 may be mixed thereby to obtain gas turbine fuel (GTF) that has
vanadium (V) content of 0.5 wt ppm or lower.
According to the oil refining method described above, since a part of the HDMS
refined oil M15 and at least a part of the hydrorefined oil M3 are mixed in the third mixing
process 23, vanadium (V) content of the mixture oil thus obtained becomes sufficiently low,
and it is possible to obtain gas turbine fuel as one of the petroleum product. It is also
possible to obtain an intermediate oil product having sufficiently low metal content (V +
Ni) that can be used as the feed for a fluid catalytic cracking or a hydrocracking process,
even from the remainder of HDMS refined oil M15 obtained from a mixture of the vacuum
gas oil M7 and the deasphalted oil M13 by hydrodemetalizating/desulfurizing process, and
therefore a plurality of oil products having a high added value can be produced at the same
time.
Since the intermediate oil product used as the feed for fluid catalytic cracking
(FCC) or hydrocracking (HCR) process has a higher tolerable concentrations of metal
contents than that of gas turbine fuel (GTF) or the like, the yield of deasphalted oil M13 in
the solvent deasphalting process 21 can be improved by producing the gas turbine fuel and
the feed for a fluid catalytic cracking or a hydrocracking process at the same time, thereby
suppressing the production of asphaltene (pitch) M14 from the vacuum residue M12.
Now fourth through sixth embodiments that can be preferably applied when
low-sulfur crude is used as the feed oil will be described below. The low-sulfur crude in
this specification refers to crude oil such as Arabian Light, Iranian Light, Iranian Heavy,
Marban, and other crude oil that includes sulfur content in a concentration similar to or
lower than those of the former species, specifically crude oils including a sulfur content of
2.0 wt % or lower.
The hydrorefining process (HT process) 2 of the first embodiment that deals with
heavy crude oil is omitted in the following embodiments because low-sulfur crude is used.
In other respects, basically the same processes as those of the first embodiment are carried
out. In the description that follows, processes identical to those of the first embodiment
will be indicated by adding a letter A to the end of the reference numeral used in the first
embodiment.
[Fourth embodiment]
Fig. 4 is a process flow diagram showing the fourth embodiment of the present
invention. In the fourth embodiment, the low-sulfur crude mentioned above is used as the
feed oil which is subjected to a fractional distillation process 1A and is distilled similarly
to the prior art so as to be separated into a distillate M1A consisting of low-boiling point
oil and a residue M2A having a higher boiling point. An apparatus similar to that of the
first embodiment may be used.
The distillate M1A obtained in the fractional distillation process 1A is separated
into distillates M3A, M3A' by a flasher 30.
The residue M2A obtained in the fractional distillation process 1A is deasphalted
with a solvent in a solvent deasphalting process (SDA process) 3A, thereby to obtain
deasphalted oil (DAO) M4A as an extract and asphaltene (pitch) M5A.
In the solvent deasphalting process, first the residue 2A is put into contact with
the solvent in counterflow in a solvent extraction tower and is separated into deasphalted
oil and asphaltene (pitch) that includes metal and residual carbon in high concentrations.
The deasphalted oil is recovered together with the solvent through the top of the tower, and
the solvent is separated from the recovered material in super-critical state. Asphaltene
(pitch) is recovered together with the solvent through the bottom of the tower, and the
solvent in the recovered material is removed by evaporation.
In case the refining process that follows the solvent deasphalting process 3A
includes only the hydrodemetalizating/desulfurizing process 4A, it is preferable to control
the extraction ratio of the solvent deasphalting process so that vanadium (V) content in the
deasphalted oil M4A becomes 25 wt ppm or lower.
At least a part of the deasphalted oil M4A obtained in the solvent deasphalting
process 3A is introduced into the hydrodemetalizating/desulfurizing process (HDMS
process) 4A, so that the part of the deasphalted oil is demetalized and desulfurized by
hydrogenation in the presence of hydrogen and a catalyst thereby to obtain the HDMS
refined oil M6A that has been demetalized and desulfurized. Since the
hydrodemetalizating/desulfurizing process is basically the same as the hydrorefining
process that deals with heavy crude oil described previously, and the description thereof
will be omitted.
Hydrodemetalizing and desulfurizing conditions are preferably selected so as to
obtain the HDMS refined oil M6A having vanadium (V) content of 2 wt ppm or lower,
preferably 1 wt ppm or lower, and a sulfur content of 0.5 wt % or lower, preferably 0.3
wt % or lower.
A part of the HDMS refined oil M6A obtained in the
hydrodemetalizating/desulfurizing process 4A and at least a part of the distillate M3A are
mixed in the fourth mixing process 5A thereby to obtain a petroleum product.
In order to produce gas turbine fuel (GTF) as the oil product obtained in the fourth
mixing process 5A, the mix proportion is set so as to achieve a vanadium (V) content of
0.5 wt ppm or lower in the petroleum product. In case the vanadium content of the
HDMS refined oil M6A is 1 wt ppm and the vanadium content of the distillate M3A is 0
wt ppm, for example, rate of the HDMS refined oil M6A to the distillate M3A is set to 1:1
or less (that is, the smaller proportion of the HDMS refined oil M6A) in volume proportion
for mixing.
Of the HDMS refined oil M6A obtained in the hydrodemetalizating/desulfurizing
process 4A, the remainder thereof that is not subjected to the fourth mixing process 5A is
used as an intermediate oil product to be fed to the fluid catalytic cracking (FCC) or
hydrocracking (HCR) process. Of the hydrorefined oil M3, the remainder thereof that is
not subjected to the first mixing process 5A may be used as an oil product M3A' such as
naphtha, gasoline, kerosene or gas oil.
According to the oil refining method described above, since a part of the HDMS
refined oil M6A and at least a part of the hydrorefined oil M3A are mixed, it is possible to
obtain an oil product that has a sufficiently low vanadium (V) content such as gas turbine
fuel. It is also possible to produce an intermediate oil product having a relatively low
metal content (V + Ni) that can be used as the feed for fluid catalytic cracking (FCC) or
hydrocracking (HCR) process from the remainder of the HDMS refined oil M6A, and
efficiently produce a plurality of oil products having high added values.
Since the intermediate oil product used as the feed for fluid catalytic cracking
(FCC) or hydrocracking (HCR) process has a higher tolerable concentrations of metal
contents than that of gas turbine fuel (GTF) or the like, the yield of deasphalted oil M4A
produced in the solvent deasphalting process 3A can be improved without accompanying
load of hydrodemetalizating/desulfurizing process, thereby suppressing the production of
asphaltene (pitch) M5A from the residue M2A.
Now referring to the process flow diagram of Fig. 4, in case the deasphalted oil
M4A obtained in the solvent deasphalting process 3A includes relatively low
concentrations of metals and sulfur, and is mixed with a part of the HDMS refined oil that
includes further lower concentrations of metals and sulfur so as to satisfy the requirements
for the feed stock properties for fluid catalytic cracking (FCC) or hydrocracking (HCR)
process, a part thereof may be sent through the bypass shown by reference numeral 12A in
Fig. 4 thereby to be mixed with a part of the HDMS refined oil M6A, instead of being
subjected to the hydrodemetalizating/desulfurizing process 4A, thereby to produce an
intermediate oil product used as the feed for the fluid catalytic cracking (FCC) process or
the feed for the hydrocracking (HCR) process.
[Fifth embodiment]
Fig. 5 is a process flow diagram explaining the fifth embodiment of the oil
refining method according to the present invention, in which gas turbine fuel (GTF) and
feed for fluid catalytic cracking (FCC) process or feed for hydrocracking (HCR) process
are produced at the same time from a feed oil, similarly to the embodiment shown in Fig.
4.
This embodiment is different from the embodiment shown in Fig. 4 mainly in that
vacuum fractional distillation process 6A is provided to follow the
hydrodemetalizating/desulfurizing process 4A, so as to process the HDMS refined oil M6A
in a vacuum distillation and separate it into vacuum gas oil M7A and vacuum residue
M8A.
In other words, with the oil refining method shown in Fig. 5, the HDMS refined
oil M6A obtained similarly to the example shown in Fig. 4 is distilled in a vacuum in the
vacuum fractional distillation process 6A.
In the vacuum fractional distillation process, the HDMS refined oil M6A is
introduced into a vacuum distillation tower where the HDMS refined oil M6A is distilled
and separated into a low-boiling point component and a high-boiling point component,
while the vacuum gas oil M7A having the lower boiling point is obtained from the top of
the tower and the vacuum residue M8A having the higher boiling point is obtained from
the bottom of the tower.
Since the vacuum fractional distillation process described above is carried out,
extraction ratio of the deasphalted oil M4A obtained in the solvent deasphalting process
can be controlled so that desirable upper limit of the vanadium (V) content is set to, for
example, 50 wt ppm. Thus the extraction ratio can be made higher and the yield of
recovering the oil products can be improved.
The demetalizing and desulfurizing conditions for the HDMS refined oil M6A
obtained from the deasphalted oil M4A through the hydrodemetalizating/desulfurizing
process are preferably selected so as to achieve the vanadium (V) content of 20 wt ppm or
lower, preferably 10 wt ppm or lower, while the sulfur content is desirably set to 0.5 wt %
or lower, preferably 0.3 wt % or lower.
Moreover, it is desirable to set the vanadium content of the vacuum gas oil
obtained by vacuum distillation of the HDMS refined oil M6A to 1 wt ppm or lower.
Following the process described above, at least a part of the vacuum gas oil M7A
obtained in the vacuum fractional distillation process 6A and the distillate M3A are mixed
in the fifth mixing process 7A thereby to obtain one of the oil products.
In order to produce gas turbine fuel (GTF) as the oil product obtained in the fifth
mixing process 7A, vanadium (V) content is controlled to 0.5 wt ppm or lower similarly to
the example shown in Fig. 4. In that case, the mix proportion is adjusted according to the
vanadium content of the vacuum gas oil M7A similarly to the previous example. When
vanadium (V) content of the vacuum gas oil M7A is 0.5 wt ppm or lower, this may be used
as gas turbine fuel (GTF) without adding the distillate M3A.
The remainder of the vacuum gas oil M7A, the vacuum residue M8A obtained by
vacuum distillation and remainder of the HDMS refined oil M6A that is not fed to the
vacuum fractional distillation process 6A are used individually or in an appropriate
combination thereof as an intermediate oil product to be used as the feed for fluid catalytic
cracking (FCC) process or the feed for hydrocracking (HCR) process.
With the oil refining method described above, since the HDMS refined oil M6A is
subjected to vacuum distillation in the vacuum fractional distillation process 6A so as to
separate into the vacuum gas oil M7A and the vacuum residue M8A that include no
significant metal content and residual carbon content by making use of the range of boiling
points of the distillation properties, relatively high concentrations of vanadium, metals and
residual carbon can be allowed for the HDMS refined oil M6A itself, thus improving the
yield of deasphalted oil M4A in the solvent deasphalting process 3A, and therefore it is
possible to suppress the production of asphaltene (pitch) MSA from the residue M2A.
With regard to the deasphalted oil M4A obtained in the solvent deasphalting
process 3A, too, in case the vanadium (V) content of M4 is sufficiently low, a part of the
M4 may be introduced into the bypass 12A to be mixed with the vacuum residue M8A sent
from the vacuum fractional distillation process 6A, instead of being subjected to the
hydrodemetalizating/desulfurizing process 4A, thereby to produce intermediate oil
products used as the feed for fluid catalytic cracking (FCC) or hydrocracking (HCR)
process. The HDMS refined oil M6A obtained in the hydrodemetalizating/desulfurizing
process 4A may also be introduced into the bypass 12A to be mixed with the vacuum
residue M8A sent from the vacuum fractional distillation process 6A thereby to produce
intermediate oil products used as the feed for fluid catalytic cracking (FCC) or
hydrocracking (HCR) process.
[Sixth embodiment]
Fig. 6 is a process flow diagram explaining the sixth embodiment of the oil
refining method according to the present invention, for a case of producing gas turbine fuel
(GTF) and feed for fluid catalytic cracking (FCC) process or feed for hydrocracking
(HCR) process at the same time from a feed oil, similarly to the embodiment shown in Fig.
4.
This embodiment is different from the embodiment shown in Fig. 4 mainly in that
the fractional distillation process 1A is followed by a vacuum fractional distillation process
20A wherein the residue M2A is separated into vacuum gas oil M11A and vacuum residue
M12A by vacuum distillation, a solvent deasphalting process 21A wherein the vacuum
residue M12A is separated into deasphalted oil M13A and asphaltene (pitch) M14A by
solvent deasphalting, and a hydrodemetalizating/desulfurizing process 22A wherein a
mixture of the deasphalted oil M13A and the vacuum gas oil M11A is subjected to
hydrodemetalizating/desulfurizing process thereby to produce HDMS refined oil M15A.
With the oil refining method shown in Fig. 6, the residue M2A obtained similarly
to the example shown in Fig. 4 is distilled in a vacuum in the vacuum fractional distillation
process 20A.
In the vacuum fractional distillation process, the residue M2A is introduced into a
vacuum distillation tower where the M2A is distilled and separated into a low-boiling point
component and a high-boiling point component, while the vacuum gas oil M11A having
the lower boiling point is obtained from the top of the tower and the vacuum residue M12A
having the higher boiling point is obtained from the bottom of the tower.
The vacuum fractional distillation process 20A is followed by the solvent
deasphalting process 21A where the vacuum residue M12A obtained in the former process
is separated into deasphalted oil M13A and asphaltene (pitch) M14A. While the vacuum
fractional distillation process is similar to the cases shown in Fig. 4 and Fig. 5, the
extraction ratio of the deasphalted oil M13A obtained in the solvent deasphalting process
of the vacuum residue is controlled so that the desirable upper limit of the vanadium (V)
content rises to, for example, 70 wt ppm in correspondence to the concentrations of metals,
residual carbon, and sulfur in M13A that are higher than those of the residue M2A.
Then the deasphalted oil M13A and the vacuum gas oil M11A thus obtained are
mixed and the mixture is subjected to the hydrodemetalizating/desulfurizing process,
thereby to obtain the HDMS refined oil M15A. The demetalizing and desulfurizing
conditions for the HDMS refined oil M15A thus obtained are preferably selected so as to
achieve the vanadium (V) content of 2 wt ppm or lower, preferably 1 wt ppm or lower, and
a sulfur content of 0.5 wt % or lower, preferably 0.3 wt % or lower.
Then a part of the HDMS refined oil M15A obtained in the
hydrodemetalizating/desulfurizing process 22A and the distillate M3A are mixed in the
sixth mixing process 23A thereby to obtain gas turbine fuel (GTF) as one of the oil product
that has vanadium (V) content of 0.5 wt ppm or lower.
The remainder of the HDMS refined oil M15 obtained in the
hydrodemetalizating/desulfurizing process 22A that is not fed to the sixth mixing process
23A may be used as an intermediate oil product to be used as the feed for the fluid catalytic
cracking (FCC) process or the feed for the hydrocracking (HCR) process.
In case the deasphalted oil M13A and the vacuum gas oil M11A have
significantly different concentrations of metals, residual carbon and sulfur and require
reaction conditions, particularly partial pressure of hydrogen, which are significantly
different from each other, the M13A and M11A may be, instead of being mixed, subjected
to hydrodemetalizating/desulfurizing process in separate reactors each under optimum
conditions, and then mixed with each other, or at least part of the vacuum gas oil M11A
that has been subjected to the hydrodem6talizating/desulfurizing process and at least a part
of the distillate M3A are mixed thereby to obtain gas turbine fuel (GTF) that has vanadium
(V) content of 0.5 wt ppm or lower.
According to the oil refining method described above, since a part of the HDMS
refined oil M15A and at least a part of the distillate M3A are mixed in the sixth mixing
process 23A, the vanadium (V) content of the mixed oil becomes sufficiently low and it is
possible to obtain gas turbine fuel as one of the petroleum products. It is also possible to
produce intermediate oil products of low metal content (V + Ni) used as the feed for a fluid
catalytic cracking or a hydrocracking process even from the remainder of the HDMS
refined oil M15A obtained from a mixture of the vacuum gas oil M7A and the deasphalted
oil M13A by hydrodemetalizating/desulfurizing process. Thus a plurality of intermediate
oil products having a high added value can be produced efficiently.
Since the intermediate oil product used as the feed for fluid catalytic cracking
(FCC) or hydrocracking (HCR) process has more lenient tolerance for metal contents than
gas turbine fuel or the like, the yield of deasphalted oil M13A in the solvent deasphalting
process 21A can be improved by producing the gas turbine fuel (GTF) and feed for the
fluid catalytic cracking (FCC) process or feed for the hydrocracking (HCR) process at the
same time, thereby suppressing the production of asphaltene (pitch) M14A from the
vacuum residue M12A.
EXPERIMENT EXAMPLES
Now the present invention will be described below more specifically by way of
experimental examples.
(Experimental Example 1)
A plurality of oil products including gas turbine fuel and intermediate oil products
to be used as the feed for a fluid catalytic cracking or a hydrocracking process were
produced as shown in Fig. 7 by the oil refining method shown in Fig. 1.
An ultra heavy crude (Orinoco oil) having an API gravity of 8.5, a sulfur content
of 3.67 wt% and a vanadium content of 393 wt ppm was used as feed oil that was first
distilled under atmospheric pressure (fractional distillation process 1) in a topper thereby to
obtain distillate M1 and residue M2. The yield of the distillate M1 was 15.9 wt% of the
feed oil and the sulfur content was 2.41 wt%. The yield of the residue M2 was 83.5 wt%
of the feed oil, while the sulfur content was 4.07 wt% and the vanadium content was 472
wt ppm.
Then the distillate M1 thus obtained was desulfurized in hydrorefining process 2
in the presence of hydrogen and catalyst, thereby to obtain hydrorefined oils M3, M3'.
M3' was used as a petroleum product, naphtha, without applying further processing. The
yield of the hydrorefined oil M3 was 13.0 wt% of the feed oil and the sulfur content was
0.02 wt%. The yield of naphtha M3' was 2 wt% of the feed oil.
Apart from the hydrorefining process, the residue M2 was subjected to the solvent
deasphalting process 3 in a solvent extraction tower using isobutane as the solvent, thereby
to obtain deasphalted oil M4 with 65% extraction ratio and asphaltene (pitch) M5 as the
residue. The ratio of the solvent to the residue M2 (solvent/M2) in the solvent
deasphalting process was set to 8. The yield of the deasphalted oil M4 was 54.3 wt% of
the feed oil, while the sulfur content was 3.60 wt%, the vanadium content was 66 wt ppm,
and the extraction ratio was 14%. The yield of the asphaltene (pitch) M5 was 29.2 wt%
of the feed oil.
The deasphalted oil M4 thus obtained was introduced into a reactor filled with a
hydrodemetalizing catalyst and a hydrodesulfurizing catalyst in a ratio of 3:7 in volume
proportion, thereby to obtain the HDMS refined oil M6 through
hydrodemetalizating/desulfurizing process 4 in the presence of hydrogen and the catalysts.
The process conditions were set to partial pressure of hydrogen of 100 atm, and the H2 to
oil ratio of 800 Nl/l. The LHSV was 0.7/hr and the reaction temperature was 370°C.
The yield of the HDMS refined oil M6 was 51 wt% of the feed oil, the sulfur content was
0.4 wt%, and the vanadium content was 0.7 wt ppm.
Then 15 wt% (in terms of yield from the fed oil) of the HDMS refined oil M6 thus
obtained was mixed with the hydrorefined oil M3 (first mixing process 5) thereby to
produce a gas turbine fuel (GTF) with a yield of 28 wt% of the feed oil, a sulfur content of
0.22 wt%, and a vanadium content of 0.38 wt ppm. The remainder, namely 36 wt% (in
terms of yield from the fed oil) of the HDMS refined oil M6 was used as a feed stock for
the fluid catalyst cracking (FCC) process or a feed stock for the hydrocracking (HCR)
process without applying further processing.
(Experimental Example 2)
A plurality of oil products including gas turbine fuel and intermediate oil products
to be used as the feed for a fluid catalytic cracking or a hydrocracking process were
produced as shown in Fig. 8 by the oil refining method shown in Fig. 2.
The ultra heavy crude (Orinoco oil) having an API gravity of 8.5, a sulfur content
of 3.67 wt% and a vanadium content of 393 wt ppm was used as feed oil that was first
distilled under atmospheric pressure (fractional distillation process 1) in a topper thereby to
obtain distillate M1 and residue M2. The yield of the distillate M1 was 15.9 wt% of the
feed oil and the sulfur content was 2.41 wt%. The yield of the residue M2 was 83.5 wt%
of the feed oil, while the sulfur content was 4.07 wt% and the vanadium content was 472
wt ppm.
Then the distillate M1 thus obtained was desulfurized in hydrorefining process 2
in the presence of hydrogen and catalyst, thereby to obtain hydrorefined oils M3, M3'.
M3' was used as a petroleum product, naphtha, without applying further processing. The
yield of the hydrorefined oil M3 was 13.0 wt% of the feed oil and the sulfur content was
0.02 wt%. The yield of naphtha M3' was 2 wt% of the feed oil.
Apart from the hydrorefining process, the residue M2 was subjected to the solvent
deasphalting process 3 in a solvent extraction tower using pentane as the solvent, thereby
to obtain deasphalted oil M4 with a 76.6% extraction ratio and asphaltene (pitch) M5 as the
residue. The ratio of the solvent to the residue M2 (solvent/M2) in the solvent
deasphalting process was set to 8. The yield of the deasphalted oil M4 was 64 wt% of the
feed oil, the sulfur content was 3.9 wt%, the vanadium content was 130 wt ppm and the
extraction ratio was 27.5%. The yield of the asphaltene (pitch) M5 was 19.5 wt% of the
feed oil.
The deasphalted oil M4 thus obtained was introduced into a reactor filled with a
hydrodemetalizing catalyst and a hydrodesulfurizing catalyst in a ratio of 5:5 in volume
proportion, thereby to obtain the HDMS refined oil M6 through
hydrodemetalizating/desulfurizing process 4 in the presence of hydrogen and the catalysts.
The process conditions were set to partial pressure of hydrogen of 100 atm, H2 to oil ratio
of 800 Nl/1. The LHSV was 0.5/hr and reaction temperature was 370°C. The yield of
the HDMS refined oil M6 was 59 wt% of the feed oil, the sulfur content was 0.45 wt%,
and the vanadium content was 8 wt ppm.
Then the HDMS refined oil M6 thus obtained was distilled in a vacuum (vacuum
fractional distillation process 6) thereby to obtain a vacuum gas oil (VGO) M7 and the
vacuum residue M8. The yield of the vacuum gas oil M7 was 25 wt% of the feed oil, the
sulfur content was 0.24 wt%, and the vanadium content was 0.3 wt ppm.
All of the vacuum gas oil M7 was mixed with the hydrorefined oil M3 (second
mixing process 7) thereby to produce gas turbine fuel (GTF) with a yield of 38 wt% of the
feed oil, a sulfur content of 0.16 wt%, and a vanadium content of 0.19 wt ppm. The
vacuum residue M8 obtained in the vacuum fractional distillation process was used as a
feed stock for the fluid catalyst cracking (FCC) process or a feed stock for the
hydrocracking (HCR) process without applying further processing. The feed stock for the
fluid catalyst cracking (FCC) process or the feed stock for the hydrocracking (HCR)
process may also be obtained by mixing a part of the deasphalted oil M4 or a part of the
HDMS refined oil M6 with the vacuum residue M8. The feed stock for the fluid catalyst
cracking (FCC) process or the feed stock for the hydrocracking (HCR) process that is
obtained in this way showed yield of 34 wt% of the feed oil, a sulfur content of 0.60 wt%,
and a vanadium content of 13.7 wt ppm.
(Experimental Example 3)
A plurality of oil products including gas turbine fuel and intermediate oil products
to be used as the feed for a fluid catalytic cracking or a hydrocracking process were
produced as shown in Fig. 9 by the oil refining method shown in Fig. 3.
An ultra heavy crude (Arabian heavy) having an API gravity of 28, a sulfur
content of 2.9 wt% and a vanadium content of 69 wt ppm was used as feed oil that was
first distilled under atmospheric pressure (fractional distillation process 1) in a topper
thereby to obtain distillate M1 and residue M2. The yield of the distillate M1 was 41
wt% of the feed oil and the sulfur content was 0.79 wt%. The yield of the residue M2
was 58.5 wt% of the feed oil, while the sulfur content was 4.72 wt% and the vanadium
content was 117 wt ppm.
Then the residue M2 thus obtained was subjected to vacuum fractional distillation
process 20 thereby to obtain a vacuum gas oil M11 and vacuum residue M12. The yield
of the vacuum gas oil M11 was 28.2 wt% of the feed oil, the sulfur content was 3.37 wt%,
and the vanadium content was 1.5 wt ppm. The yield of the vacuum residue M12 was
30.6 wt% of the feed oil, the vanadium content was 223 wt ppm, (V + Ni) content was 294
wt ppm, residual carbon content was 24.4% and the sulfur content was 6.04 wt%.
Fractions of LPG, naphtha, kerosene, and gas oil obtained from the distillate M1
were refined separately by hydrogenation (hydrorefining process 2) thereby to obtain
corresponding hydrorefined oils (light fractions) M3, M3'. The yield of the hydrorefined
oil M3 was 20.3 wt% of the feed oil and the sulfur content was 0.05 wt%. The yield of
the gasoline, kerosene, and gas oil from the hydrorefined oil M3' was 6.0 wt% and 13.7
wt%, respectively, of the feed oil.
Apart from the hydrorefining process, the vacuum residue M12 was subjected to
the solvent deasphalting process 21 in a solvent extraction tower using isobutane as the
solvent, thereby to obtain deasphalted oil M13 with a 60% extraction ratio and asphaltene
(pitch) M14 as the residue. The ratio of the solvent to the vacuum residue M12
(solvent/M12) in the solvent deasphalting process was set to 8. The yield of the
deasphalted oil M13 was 18.4 wt% of the feed oil, the sulfur content was 4.62 wt%, the
vanadium content was 22 wt ppm and the extraction ratio was 19%. The yield of the
asphaltene (pitch) M14 was 12.2 wt% of the feed oil.
A mixture of the deasphalted oil M13 and the vacuum gas oil M11 was introduced
into a reactor filled with a hydrodemetalizing catalyst and a hydrodesulfurizing catalyst in
a ratio of 1:9 in volume proportion, thereby to obtain the HDMS refined oil M15 through
hydrodemetalizating/desulfurizing process 4 in the presence of hydrogen and the catalysts.
The process conditions were set to partial pressure of hydrogen of 90 atm, the H2 to oil
ratio of 800 Nl/l. The LHSV was 0.7/hr and reaction temperature was 370°C. The yield
of the HDMS refined oil M15 was 44 wt% of the feed oil, the sulfur content was 0.6 wt%,
and the vanadium content was 1.0 wt ppm.
Then 15 wt% (in proportion to the fed oil) of the HDMS refined oil M15 thus
obtained was mixed with the hydrorefined oil M3 thereby to produce gas turbine fuel that
included sulfur content of 0.28 wt%, and a vanadium content of 0.42 wt ppm with a yield
of 45 wt% of the feed oil. The remainder, specifically, 29 wt% of the HDMS refined oil
was used as a feed stock for the fluid catalyst cracking (FCC) process or hydrocracking
(HCR) process.
Now experimental examples that used low-sulfur content crude oil will be
described below.
(Experimental Example 4)
A plurality of oil products including gas turbine fuel and intermediate oil products
to be used as the feed for a fluid catalytic cracking or a hydrocracking process were
produced as shown in Fig. 10 by the oil refining method shown in Fig. 4.
A low-sulfur content crude oil (Arabian light) having a sulfur content of 1.79 wt%
and a vanadium content of 13.5 wt ppm was used as feed oil that was first distilled under
atmospheric pressure (fractional distillation process 1A) in a topper thereby to obtain
distillate M1A and residue M2A. The yield of the distillate M1A was 53.5 wt% of the
feed oil and the sulfur content was 0.63 wt%. The yield of the residue M2A was 45.4
wt% of the feed oil, while the sulfur content was 3.20 wt% and the vanadium content was
30.0 wt ppm.
The distillate M1A thus obtained was separated in a flasher 30 thereby to obtain
distillates M3A, M3A'. M3' was used as a petroleum product, naphtha, without applying
further processing. The yield of the distillate M3A was 50.9 wt% of the feed oil and the
sulfur content was 0.66 wt%. The yield of naphtha M3' was 2.6 wt% of the feed oil.
The residue M2A was subjected to the solvent deasphalting process 3A in a
solvent extraction tower using isobutane as the solvent, thereby to obtain deasphalted oil
M4A with 65% extraction ratio and asphaltene (pitch) M5A as the residue. The ratio of
the solvent to the residue M2A (solvent/M2A) in the solvent deasphalting process was set
to 8. The yield of the deasphalted oil M4A was 38.6 wt% of the feed oil, the sulfur
content was 2.80 wt%, and the vanadium content was 5.9 wt ppm. The yield of the
asphaltene (pitch) M5A was 6.8 wt% of the feed oil.
The deasphalted oil M4A thus obtained was introduced into a reactor filled with a
hydrodemetalizing catalyst and a hydrodesulfurizing catalyst in a ratio of 1:9 in volume
proportion, thereby to obtain the HDMS refined oil M6A through
hydrodemetalizating/desulfurizing process 4A in the presence of hydrogen and the
catalysts. The process conditions were set to partial pressure of hydrogen of 100 atm, H2
to oil ratio of 800 Nl/l. The LHSV was 0.5/hr and the reaction temperature was 370°C.
The yield of the HDMS refined oil M6A was 36.3 wt% of the feed oil, the sulfur content
was 0.10 wt%, and the vanadium content was 0.9 wt ppm.
Then 22.7 wt% (in terms of yield from the fed oil) of the HDMS refined oil M6A
thus obtained was mixed with the distillate M3A (fourth mixing process 5A) thereby to
produce gas turbine fuel (GTF) that included a sulfur content of 0.49 wt%, and a vanadium
content of 0.28 wt ppm with a yield of 73.6 wt% of the feed oil. The remainder of the
HDMS refined oil M6A, namely 13.6 wt% (in terms of yield from the fed oil) thereof was
used as a feed stock for the fluid catalyst cracking (FCC) process or a feed stock for the
hydrocracking (HCR) process without applying further processing.
(Experimental Example 5)
A plurality of oil products including gas turbine fuel and intermediate oil products
to be used as the feed for a fluid catalytic cracking or a hydrocracking process were
produced as shown in Fig. 11 by the oil refining method shown in Fig. 5.
The low-sulfur content crude oil (Arabian light), the same oil as that used in the
fourth experimental example, having a sulfur content of 1.79 wt% and a vanadium content
of 13.5 wt ppm was used as the feed oil that was first distilled under atmospheric pressure
(fractional distillation process 1A) in a topper thereby to obtain distillate M1A and residue
M2A. The yield of the distillate M1A was 53.5 wt% of the feed oil and the sulfur content
was 0.63 wt%. The yield of the residue M2A was 45.4 wt% of the feed oil, while the
sulfur content was 3.20 wt% and the vanadium content was 30.0 wt ppm.
The distillate M1A thus obtained was separated in the flasher 30 thereby to obtain
distillates M3A, M3A'. The distillate M3A was used as a petroleum product, naphtha,
without applying further processing. The yield of the distillate M3A was 50.9 wt% of the
feed oil and the sulfur content was 0.66 wt%. The yield of naphtha M3A' was 2.6 wt% of
the feed oil.
Apart from the hydrorefining process, the residue M2A was subjected to the
solvent deasphalting process 3A in a solvent extraction tower using pentane as the solvent,
thereby to obtain deasphalted oil M4A with 65% extraction ratio and asphaltene (pitch)
M5A as the residue. The ratio of the solvent to the residue M2A (solvent/M2) in the
solvent deasphalting process was set to 8. The yield of the deasphalted oil M4A thus
obtained was 38.6 wt% of the feed oil, the sulfur content was 2.80 wt%, and the vanadium
content was 5.9 wt ppm. The yield of the asphaltene (pitch) M5A was 6.8 wt% of the
feed oil.
The deasphalted oil M4A was introduced into a reactor filled with a
hydrodemetalizing catalyst and a hydrodesulfurizing catalyst in a ratio of 1:9 in volume
proportion, thereby to obtain the HDMS refined oil M6A through
hydrodemetalizating/desulfurizing process 4A in the presence of hydrogen and the
catalysts. The process conditions were set to partial pressure of hydrogen of 100 atm, H2
to oil ratio of 800 Nl/l. The LHSV was 0.7/hr and the reaction temperature was 360°C.
The yield of the HDMS refined oil M6A was 36.3 wt% of the feed oil, the sulfur content
was 0.30 wt%, and the vanadium content was 1.5 wt ppm.
Then the HDMS refined oil M6A thus obtained was distilled in a vacuum
(vacuum fractional distillation process 6A) thereby to obtain a vacuum gas oil (VGO)
M7A and the vacuum residue M8A. The yield of the vacuum gas oil M7A thus obtained
was 23.0 wt% of the feed oil, the sulfur content was 0.10 wt%, and the vanadium content
was 0.2 wt ppm.
All of the vacuum gas oil M7A was mixed with the distillate M3A (fifth mixing
process 7A) thereby to produce gas turbine fuel (GTF) that included a sulfur content of
0.49 wt% and a vanadium content of 0.06 wt ppm, with a yield of 73.9 wt% of the feed oil.
The vacuum residue M8A obtained in the vacuum fractional distillation process was used
as a feed stock for the fluid catalyst cracking (FCC) process or a feed stock for the
hydrocracking (HCR) process without applying further processing. The feed stock for the
fluid catalyst cracking (FCC) process or the feed stock for the hydrocracking (HCR)
process may also be obtained by mixing a part of the deasphalted oil M4A or a part of the
HDMS refined oil M6A with the vacuum residue M8A. The feed stock for the fluid
catalyst cracking (FCC) process or the feed stock for the hydrocracking (HCR) process
obtained in this way showed yield of 13.3 wt% of the feed oil, a sulfur content of 0.65 wt%,
and a vanadium content of 3.7 wt ppm.
(Experimental Example 6)
A plurality of oil products including gas turbine fuel and intermediate oil products
used as the feed for a fluid catalytic cracking or a hydrocracking process were produced as
shown in Fig. 12 by the oil refining method shown in Fig.. 6.
The low-sulfur content crude oil (Arabian light), the same oil as that used in the
fourth experimental example, having a sulfur content of 1.79 wt% and a vanadium content
of 13.5 wt ppm was used as feed oil that was first distilled under atmospheric pressure
(fractional distillation process 1A) in a topper thereby to obtain distillate M1A and residue
M2A. The yield of the distillate M1A was 53.5 wt% of the feed oil and the sulfur content
was 0.63 wt%. The yield of the residue M2A was 45.4 wt% of the feed oil, while the
sulfur content was 3.20 wt% and the vanadium content was 30.0 wt ppm.
The residue M2A thus obtained was distilled in a vacuum (vacuum fractional
distillation process 20A) thereby to obtain a vacuum gas oil M11A and vacuum residue
M12A. The yield of the vacuum gas oil M11A was 30.4 wt% of the feed oil, while the
sulfur content was 2.70 wt% and the vanadium content was 0.1 wt ppm. The yield of the
vacuum residue M12A was 15.0 wt% of the feed oil, while the vanadium content was 91.0
wt ppm and the sulfur content was 4.10 wt%.
The distillate M1A was separated in the flasher 30 thereby to obtain distillates
M3A, M3A'. The distillate M3A' was used as one of the petroleum product, naphtha,
without applying further processing. The yield of the distillate M3A was 50.9 wt% of the
feed oil and the sulfur content was 0.66 wt%. The yield of naphtha M3A' was 2.6 wt% of
the feed oil.
Apart from the hydrorefining process, the vacuum residue M12A was subjected to
the solvent deasphalting process 21A in a solvent extraction tower using isobutane as the
solvent, thereby to obtain deasphalted oil M13A with a 60% extraction ratio and asphaltene
(pitch) M14A as the residue. The ratio of the solvent to the vacuum residue M12A
(solvent/M12A) in the solvent deasphalting process was set to 8. The yield of the
deasphalted oil M13A was 10.5 wt% of the feed oil, the sulfur content was 3.30 wt%, and
the vanadium content was 11.0 wt ppm. The yield of the asphaltene (pitch) M14A was
4.5 wt% of the feed oil.
A mixture of the deasphalted oil M13A and the vacuum gas oil M11A was
introduced into a reactor filled with a hydrodemetalizing catalyst and a hydrodesulfurizing
catalyst in a ratio of 1:9 in volume proportion, thereby to obtain the HDMS refined oil
M15A through hydrodemetalizating/desulfurizing process 22A in the presence of hydrogen
and the catalysts. The process conditions were set to partial pressure of hydrogen of 100
atm, H2 to oil ratio of 800 Nl/1. The LHSV was 0.5/hr and the reaction temperature was
375°C. The yield of the HDMS refined oil M15A was 38.4 wt% of the feed oil, while the
sulfur content was 0.10 wt%, and the vanadium content was 0.9 wt ppm.
Then 22.7 wt% (in proportion to the fed oil) of the HDMS refined oil M15A thus
obtained was mixed with the distillate M3A thereby to produce gas turbine fuel that
included a sulfur content of 0.49 wt% and a vanadium content of 0.28 wt ppm, with a yield
of 73.6 wt% of the feed oil. The remainder of the HDMS refined oil, namely 15.7 wt%
thereof was used as a feed stock for the fluid catalyst cracking (FCC) process or
hydrocracking (HCR) process without applying further processing.
INDUSTRIAL APPLICABILITY
The oil refining method according to the present invention makes it possible to
produce, for example, oil product (gas turbine fuel) having vanadium (V) content of 0.5 wt
ppm or lower, and intermediate oil products having metal (V + Ni) content of 30 wt ppm or
lower that is suitable as the feed stock to be used in the fluid catalyst cracking (FCC)
process or in the hydrocracking (HCR) process, from a heavy feed oil such as Orinoco tar
or a feed oil having low sulfur content.