JPH10183143A - Hydrogenation of heavy hydrocarbon oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for hydrogenation capable of suppressing the polymerization reaction of asphaltene, reducing the coke deactivation of a catalyst and prolonging the life of the catalyst by hydrogenating a radicalized asphaltene. SOLUTION: This method for hydrogenating a heavy hydrocarbon oil comprises (a) subjecting the heavy hydrocarbon oil of a feed raw material to hydrogenating metal removal treatment by a first reaction column, (b) hydrogenating the heavy hydrocarbon oil subjected to the hydrogenating metal removal treatment by the process (a) at a reaction temperature lower than that of the process (a) by a second reaction column and further (c) hydrogenating the heavy hydrocarbon oil treated by the process (b) at a reaction temperature higher than that of the process (a) by a third reaction column.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hydrotreating heavy hydrocarbon oils, and more particularly, to a method for hydrotreating heavy hydrocarbon oils by suppressing the production of coke precursor substances. The present invention relates to a hydrotreating method capable of suppressing catalyst deactivation by coke (carbonaceous substance) deposited thereon and extending catalyst life.

[0002]

2. Description of the Related Art Conventionally, in the hydrotreating of hydrocarbon oils, especially heavy hydrocarbon oils such as crude oils containing asphaltenes, sulfur, metals, etc., atmospheric residual oils, and vacuum residual oils, metallization occurs during the treatment. There is a problem that the catalyst activity is reduced due to precipitation of coke and coke on the catalyst, and the catalyst life is shortened.

[0003] As a method of extending the life of the catalyst, two pre-reaction towers are installed in parallel in front of the main reaction tower. A treatment method in which a metal reaction is performed and then a hydrodesulfurization reaction is performed in the main reaction tower, and when the catalyst in the pre-reaction tower is deactivated due to deposition of metal, a method is proposed in which the treatment is switched to another pre-reaction tower. (Japanese Patent Publication No. 49-6163).

However, although this method has a modest effect on the deactivation of the catalyst due to the deposition of metal, it has no effect on the deactivation of the catalyst due to the deposition of coke. This is because the deposition of metal on the catalyst occurs in the former stage of the catalyst layer, and the deposition of coke on the catalyst occurs in the latter stage of the catalyst layer.

[0005] As a method of extending the catalyst life focusing on the deactivation due to coke described above, in hydrotreating a heavy hydrocarbon oil in the presence of a catalyst, the raw material oil is flowed in a certain direction and is treated for a predetermined time. A method for hydrotreating hydrocarbon oils has been proposed in which the flow of the feedstock oil to the catalyst is reversed in accordance with the performance degradation (JP-A-7-331254).

Further, as a method for hydrotreating heavy oil, which can stably operate the hydrotreating apparatus continuously for a long period of time by remarkably suppressing coke generated during the hydrotreating of heavy oil, A method has been proposed in which 0.3 to 15% by weight of oil is blended with at least one oil selected from coal liquefied oil and oil obtained from coal tar, tar sands, oil shale or bitumen, and hydrotreated. (JP-A-7-316566).

[0007] However, the above-mentioned method is not sufficiently effective in suppressing coke deactivation and is not always satisfactory with respect to prolonging the catalyst life.

[0008]

In the conventional hydrotreating method, asphaltene contained in heavy hydrocarbon oil is treated with a demetallizing catalyst to remove metal components such as nickel and vanadium present in the asphaltene structure. Then, a part of the asphaltene structure becomes a radical state.
The asphaltene in the radical state is sent to the subsequent hydrodesulfurization catalyst layer without being hydrogenated because the hydrogenation ability of the demetallation catalyst is low, but the reaction temperature of the hydrodesulfurization catalyst layer is high, so It was found that the asphaltene in a radical state was polymerized and coked without being hydrogenated here.

An object of the present invention is to provide a hydrotreating method capable of suppressing the polymerization reaction by hydrogenating the above-mentioned radicalized asphaltenes, reducing the coke deactivation of the catalyst and extending the life of the catalyst. The point is to provide.

[0010]

SUMMARY OF THE INVENTION The present invention comprises: (a) hydrodemetallizing a feedstock heavy hydrocarbon oil;
(B) hydrotreating the heavy hydrocarbon oil hydrodemetallized in step (a) at a reaction temperature lower than the reaction temperature in step (a); The present invention relates to a method for hydrotreating heavy hydrocarbon oil, which comprises hydrotreating heavy hydrocarbon oil subjected to hydrotreating at a reaction temperature higher than the reaction temperature in step (a). The reaction temperature in the step (b) is preferably 370 ° C. or lower.

The feedstock oil to be hydrotreated in the present invention is:
It is a hydrocarbon oil containing asphaltene, sulfur, nitrogen, and metal components such as vanadium and nickel, and includes heavy hydrocarbon oils such as crude oil, atmospheric residual oil, and vacuum residual oil.

In the step (a) of the present invention, the above-mentioned feedstock oil is subjected to hydrodemetallization treatment in a reaction tower filled with a hydrodemetallization catalyst. Hydrodemetallization conditions in the hydrotreating method are employed. Preferably, while increasing the reaction temperature in the range of 370 to 420 ° C. according to the deterioration of the demetalization catalyst,
The partial pressure of hydrogen is operated in the range of 50 to 250 kg / cm ² . The reaction temperature in the present specification means the weight average reaction temperature (WAT) of each catalyst layer.

Further, as the hydrodemetallation catalyst used in the step (a) of the present invention, an ordinary hydrodemetallation catalyst used in a conventional hydrotreating method can be employed.
Preferred hydrodemetallation catalysts include MoO ₃ and / or WO ₃ in an Al ₂ O ₃ -containing support in an amount of 0.5 to 15 wt%,
A catalyst containing CoO and / or NiO in a range of 0.5 to 5% by weight and having a pore volume of 0.4 to 1.1 ml /
g, average pore diameter is 70 to 2000 °, specific surface area is 10
0 to 400 m ² / g, average diameter of catalyst particles is 1/32 to
Those in the range of 1/4 inch are exemplified.

In the step (b) of the present invention, the heavy hydrocarbon oil hydrodemetallized in the step (a) is treated with the (a)
The hydrogenation treatment is performed at a reaction temperature lower than the reaction temperature of the step, but when the reaction temperature of the step (b) is high, the metal components such as nickel and vanadium present in the asphaltene structure are removed by the demetalization treatment of the step (a). Since the asphaltene in which a part of the structure is in a radical state is polymerized without being hydrogenated and may be coked, the reaction temperature in the step (b) is preferably 370 ° C. or lower. In order to more effectively hydrogenate the above-mentioned radicalized asphaltenes and suppress the polymerization reaction, the reaction temperature in the step (b) is more preferably 360 ° C or lower, and further preferably 200 to 350 ° C. . Other hydrotreating conditions may be the same as those in a normal hydrotreating method.

The hydrotreating catalyst used in the step (b) may be a porous inorganic oxide carrier such as alumina, silica-alumina, silica, titania-alumina, and zircona-alumina. , Pd, Pt, Re,
What has usual hydrogenation ability, such as a catalyst which carried active metal components, such as Ru and Rh, is used. Preferred hydrotreating catalysts used in step (b) include Al ₂ O ₃
8 to 30 wt% of MoO ₃ and / or WO ₃ in the containing carrier,
A catalyst containing CoO and / or NiO in a range of 1 to 10% by weight, having a pore volume of 0.4 to 1.0 ml.
/ G, average pore diameter 70-300 °, specific surface area 10
0 to 400 m ² / g, average diameter of catalyst particles is 1/32 to
Those in the range of 1/4 inch are exemplified.

In the step (c) of the present invention, the heavy hydrocarbon oil hydrotreated in the step (b) is hydrotreated at a reaction temperature higher than the reaction temperature in the step (a). c)
If the reaction temperature in the step is low, sufficient desulfurization activity may not be obtained. As the hydrotreating conditions in the step (c), hydrotreating conditions in a normal hydrotreating method are employed. Preferably, while increasing the reaction temperature in the range of 371 to 450 ° C. in accordance with the deterioration of the hydrotreating catalyst so that the sulfur content of the produced oil is constant, the hydrogen partial pressure is 50 to 250 kg / cm.
Driven in ^two ranges.

Further, as the hydrotreating catalyst used in the step (c) of the present invention, an ordinary hydrotreating catalyst used in a conventional hydrotreating method can be employed. Preferred hydrotreating catalysts include MoO _{3 on} an Al ₂ O ₃ -containing support.
And / or WO ₃ and 8~30wt%, a catalyst containing at CoO and / or range of NiO of 110 wt.%, A pore volume of 0.4~1.0ml / g, average pore diameter 70-300 °, specific surface area 100-400 m ² /
g, those having an average diameter of the catalyst particles in the range of 1/32 to 1/4 inch.

An embodiment of the present invention will be described below in accordance with the hydrotreating method shown in FIG. In the hydrotreating method of the present invention,
(A) A heavy hydrocarbon oil as a feedstock is subjected to hydrodemetallization in a first reaction column filled with a hydrodemetallization catalyst, and then (b) the hydrodemetallized heavy oil in step (a). The high-quality hydrocarbon oil is hydrotreated in a second reaction tower filled with a hydrodesulfurization catalyst at a reaction temperature lower than the reaction temperature in the step (a), and further, in the steps (c) and (b). The heavy hydrocarbon oil thus obtained is hydrotreated at a reaction temperature higher than the reaction temperature in the step (a) in a third reaction tower filled with a hydrodesulfurization catalyst.

In the above-mentioned hydrotreating, the heavy hydrocarbon oil as the feedstock and the heavy hydrocarbon oil hydrodemetalized in the step (a) are heat-treated in a first heat exchanger (HE-1). It is preferable to exchange the temperature to raise the temperature of the heavy hydrocarbon oil of the feedstock and to cool the heavy hydrocarbon oil hydrodemetalized in the step (a) because it is economical in terms of thermal efficiency. .

In the above-mentioned hydrotreating, the heavy hydrocarbon oil hydrotreated in the step (b) and (c)
The heavy hydrocarbon oil hydrotreated in the step is heat-exchanged in the second heat exchanger (HE-2) to raise the temperature of the heavy hydrocarbon oil hydrotreated in the step (b), and (c) It is preferable to cool the heavy hydrocarbon oil that has been hydrotreated in the step (3) because it is economical in terms of thermal efficiency.

Further, in the method of the present invention, the heavy hydrocarbon oil as the feedstock and the heavy hydrocarbon oil hydrodemetalized in the step (a) are heat-treated in the first heat exchanger (HE-1). The heavy hydrocarbon oil as the feedstock is exchanged to raise the temperature, and the heavy hydrocarbon oil subjected to the hydrodemetallization in the step (a) is cooled, and further subjected to the hydrogenation treatment in the step (b). Heat exchange between the heavy hydrocarbon oil obtained and the heavy hydrocarbon oil hydrotreated in the step (c) in the second heat exchanger (HE-2), and the heavy hydrocarbon oil hydrotreated in the step (b) It is preferable to raise the temperature of the hydrocarbon oil and to cool the heavy hydrocarbon oil hydrotreated in the step (c).

The method of the present invention does not limit the number of reaction columns as long as the above-mentioned hydrotreating method can be satisfied.

[0023]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Example 1 Using the reactor shown in FIG. 1, a heavy hydrocarbon oil having the properties shown in Table 1 was hydrotreated. The first reaction tower was filled with a demetalization catalyst having the properties shown in Table 5 to 1/3 of the total catalyst amount, and
The reaction tower and the third reaction tower were each filled with a hydrotreating catalyst having the properties shown in Table 5 by 1/3 of the total catalyst amount, and the sulfur concentration of the produced oil was kept constant at 0.30 wt% under the reaction conditions shown in Table 2. The first reaction tower and the third
The reactor was operated by gradually raising the reaction temperature. That is, the reaction temperature of the second reaction tower is maintained at 350 ° C., and the difference between the reaction temperature of the first reaction tower and the reaction temperature of the third reaction tower is 2
The temperature was raised to 0 ° C., and the reaction temperature of the first reaction tower and the third reaction tower was gradually increased in accordance with the deactivation of the catalyst, and the operation was performed.

[0025]

[Table 1] Raw material properties Normal pressure residual oil Density @ 15 ° C 0.9900 g / cm ³ Sulfur concentration 4.20 wt% Ni + V 80 ppm

[0026]

Table 2 Reaction conditions Hydrogen pressure 13 MPa Liquid hourly space velocity (LHSV) 0.20 Hr ^-1 Hydrogen / oil ratio 800 NL / L

Table 6 shows the respective reaction temperatures of the first, second and third reaction towers and their average reaction temperatures. FIG. 2 shows the temperature rise curve of the average reaction temperature. The average reaction temperature was determined by weight average temperature (WAT). From Table 6 and FIG. 2, it can be seen that the method of the present invention has a lower average reaction temperature and a longer catalyst life than the conventional method.

Comparative Example 1 In Example 1, the produced oil was supplied to the first heat exchanger (HE-1).
And the second heat exchanger (HE-2) and the first reaction tower, the second reaction tower and the second reaction tower according to the deactivation of the catalyst so as to keep the sulfur concentration of the produced oil constant at 0.30 wt%. Except that the reaction temperature of the third reaction column was gradually raised and operated.
A catalyst life test was performed in exactly the same manner as in Example 1. The results are shown in Table 6 and FIG.

Example 2 Using the reactor shown in FIG. 1, a heavy hydrocarbon oil having the properties shown in Table 3 was hydrotreated. In the first reaction tower, a demetalization catalyst having the properties shown in Table 5 was added to 1/5 (100 c
c) packed and the second and third reaction towers were charged with a hydrotreating catalyst having the properties shown in Table 5 at 2/5 (200 c
c) Each of the first and third reaction towers was charged according to the deactivation of the catalyst so that the sulfur concentration of the produced oil was kept constant at 0.20 wt% under the reaction conditions shown in Table 4. Was gradually heated. That is, the reaction temperature of the second reaction tower is operated at a constant 360 ° C., and the difference between the reaction temperature of the first reaction tower and the reaction temperature of the third reaction tower is set to 20 ° C. The reactor was operated by gradually increasing the reaction temperature of the reaction tower and the third reaction tower.

[0030]

[Table 3] Raw material properties Normal pressure residual oil Density @ 15 ° C 0.965 g / cm ³ Sulfur concentration 3.19 wt% Ni + V 41 ppm

[0031]

Table 4 Reaction conditions Hydrogen pressure 13.5 MPa Liquid hourly space velocity (LHSV) 0.30 Hr ^-1 hydrogen / oil ratio 700 NL / L

Table 7 shows the respective reaction temperatures of the first, second and third reaction towers and their average reaction temperatures. FIG. 3 shows a temperature rise curve of the average reaction temperature. From Table 7 and FIG. 3, it can be seen that the method of the present invention has a lower average reaction temperature and a longer catalyst life than the conventional method.

Comparative Example 2 In Example 2, the produced oil was supplied to the first heat exchanger (HE-1).
Heat exchange in the second heat exchanger (HE-2) and the first reaction tower, the second reaction, etc. according to the deactivation of the catalyst so as to maintain the sulfur concentration of the produced oil constant at 0.20 wt%. And third
A catalyst life test was carried out in exactly the same manner as in Example 2 except that the reaction tower was operated while gradually raising the reaction temperature. The results are shown in Table 7 and FIG.

[0034]

[Table 5]

[0035]

[Table 6]

[0036]

[Table 7]

The embodiments of the present invention are listed below. (1) (a) The heavy hydrocarbon oil as a feedstock is subjected to hydrodemetallization treatment, and then (b) the heavy hydrocarbon oil subjected to hydrodemetallization treatment in the step (a) is subjected to the hydrodemetallization treatment in the step (a). Hydrotreating at a reaction temperature lower than the reaction temperature, and further hydrotreating the heavy hydrocarbon oil hydrotreated in the steps (c) and (b) at a reaction temperature higher than the reaction temperature in the step (a) A method for hydrotreating heavy hydrocarbon oils. (2) (a) The heavy hydrocarbon oil as a feedstock is subjected to a hydrodemetallization treatment in a first reaction column packed with a hydrodemetallization catalyst, and then (b) a hydrodemetallization step (a). The treated heavy hydrocarbon oil is hydrotreated in a second reaction tower filled with a hydrodesulfurization catalyst, and further, the heavy hydrocarbon oil hydrotreated in steps (c) and (b) is hydrogenated. At the time of hydrotreating in the third reaction tower filled with a desulfurization catalyst, (a) the heavy hydrocarbon oil as the feedstock and the heavy hydrocarbon oil hydrodemetallized in step (a) are subjected to the first process. Heat exchange in a heat exchanger to raise the temperature of the heavy hydrocarbon oil as the feedstock, and cooling the heavy hydrocarbon oil hydrodemetalized in step (a) and / or
(B) heat-exchanging the heavy hydrocarbon oil hydrotreated in the step (b) with the heavy hydrocarbon oil hydrotreated in the step (c) in a second heat exchanger; The heavy hydrocarbon oil hydrotreated in the step (c) and cooling the heavy hydrocarbon oil hydrotreated in the step (c) is cooled by the step (c). Hydrotreating method. (3) The method for hydrotreating heavy hydrocarbon oil according to the above (1) or (2), wherein the reaction temperature in the step (b) is 370 ° C. or lower. (4) The method for hydrotreating heavy hydrocarbon oil according to the above (1) or (2), wherein the reaction temperature in the step (b) is 360 ° C. or lower. (5) The reaction temperature in the step (b) is 200 to 350 ° C.
The method for hydrotreating heavy hydrocarbon oil according to the above (1) or (2), which is as follows. (6) The hydrotreating in the step (c) is performed in accordance with the deterioration of the hydrotreating catalyst so that the sulfur content of the produced oil is constant.
While increasing the reaction temperature in the range of 371 to 450 ° C,
The method for hydrotreating heavy hydrocarbon oil according to any one of (1) to (5), wherein the hydrogenation is performed at a hydrogen partial pressure in the range of 50 to 250 kg / cm ² . (7) The hydrogenation catalyst used in the step (b) has a pore volume of 0.4 to 1.0 ml / g and an average pore diameter of 70 to 300.
Å, a specific surface area of 100 to 400 m ² / g, and an average diameter of catalyst particles of 1/32 to 1/4 inch (1) to
(6) The method for hydrotreating heavy hydrocarbon oil according to any one of (1) to (4). (8) The hydrogenation catalyst used in the step (c) has a pore volume of 0.4 to 1.0 ml / g and an average pore diameter of 70 to 300.
Å, a specific surface area of 100 to 400 m ² / g, and an average diameter of catalyst particles of 1/32 to 1/4 inch (1) to
(7) The method for hydrotreating heavy hydrocarbon oil according to any one of the above (7).

[0038]

According to the present invention, the catalyst life can be extended by reducing the coke deactivation of the catalyst.

[Brief description of the drawings]

FIG. 1 is a flow sheet of a reaction apparatus used in Examples of the present invention.

FIG. 2 shows a temperature rise curve of an average reaction temperature in Example 1.

FIG. 3 shows a temperature rise curve of an average reaction temperature in Example 2.

Claims (2)

[Claims] (1) Hydrodemetallizing a heavy hydrocarbon oil as a feedstock, and (b) converting the heavy hydrocarbon oil hydrodemetallized in the step (a) into (a) Hydrogenation at a reaction temperature lower than the reaction temperature of the step, and (c)
The heavy hydrocarbon oil hydrotreated in step (b)
Hydrotreating at a reaction temperature higher than the reaction temperature of the process,
A method for hydrotreating heavy hydrocarbon oils. (2) Hydrodemetallizing a heavy hydrocarbon oil as a feedstock in a first reaction column packed with a hydrodemetallizing catalyst, and then (b) hydrogenating in step (a) The demetallized heavy hydrocarbon oil is hydrotreated in a second reaction tower filled with a hydrodesulfurization catalyst, and the heavy hydrocarbon oil hydrotreated in steps (c) and (b) is further treated. When hydrotreating in the third reaction column filled with the hydrodesulfurization catalyst, (a) the heavy hydrocarbon oil as the feedstock and the heavy hydrocarbon oil hydrodemetallized in step (a) Heat exchange in the first heat exchanger to raise the temperature of the heavy hydrocarbon oil as the feedstock, and cooling the heavy hydrocarbon oil hydrodemetalized in the step (a) and / or
(B) heat-exchanging the heavy hydrocarbon oil hydrotreated in the step (b) with the heavy hydrocarbon oil hydrotreated in the step (c) in a second heat exchanger; 2. The hydrogen of heavy hydrocarbon according to claim 1, wherein the temperature of the heavy hydrocarbon oil hydrotreated in step (c) is increased and the heavy hydrocarbon oil hydrotreated in step (c) is cooled. Treatment method.