JP2740815B2 - Two-stage hydrocracking method for petroleum heavy oil - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a lightened hydrocarbon oil by hydrocracking petroleum heavy oil in a two-stage hydrotreatment step.

(Prior art and its problems) A method of treating petroleum heavy oil by a two-stage hydrotreating process is known (JP-A-53-98308, etc.). However, many of the conventional two-stage hydrotreating processes for petroleum heavy oils are aimed at removing contaminants such as metal components and sulfur components and nitrogen components contained in petroleum heavy oils. It is not intended for hydrocracking of heavy oil.
In such a two-stage hydrotreating, the first-stage hydrotreating step is usually aimed at demetallization, and the second-stage hydrogenation step is desulfurized.

In order to hydrocrack petroleum heavy oil, there is known a method of hydrotreating heavy oil at 410 to 490 ° C under a hydrogen pressure using a catalyst having an average pore diameter of 140 mm or more. Kaisho 58
-179291). However, in such a single-stage hydrocracking method, when the hydrocracking rate is increased, catalyst deterioration is likely to occur, and dry sludge is generated in the cracked oil,
This causes a problem of deteriorating the stability and quality of the cracked oil.

(Problems of the Invention) It is an object of the present invention to solve the above-mentioned problems observed in hydrocracking of petroleum heavy oil.

(Means for Solving the Problems) The present inventors have conducted intensive studies to solve the above problems, and as a result, completed the present invention.

That is, according to the present invention, heavy petroleum oil is converted to a heavy oil by using a large pore hydrogenation catalyst having an average pore diameter of 150 ° or more.
The first hydrotreating step is performed at a temperature of 400 ° C. or less, a hydrogen pressure of 100 kg / cm ² G or more, and a hexane-insoluble, benzene-soluble component reduction rate of 90% or more and a boiling point of 540 ° C. Performed under the conditions that the decomposition rate of the above fraction is 10% or less,
And the second hydrotreating step is performed at a temperature of 400 to 460 ° C. and a hydrogen pressure of 80
A petroleum-based heavy oil which is obtained under the condition that the total cracking rate of a fraction of kg / cm ² G or more and a boiling point of 540 ° C. or more is at least 60% to obtain a hydrocracking oil substantially containing no sludge. A two-stage hydrocracking method for oil is provided.

Examples of the petroleum heavy oil used in the present invention include atmospheric residual oil, vacuum residual oil, and the like.
Containing hexane-insoluble and benzene-soluble components,
It contains 2 to 18% by weight.

In the present invention, such a heavy oil is used as a feedstock oil, and a two-stage hydrotreating process as described below is performed in order to hydrocrack it into a lightened oil.

(First Hydrotreating Step) In the first hydrotreating step, the feed oil is heated at a temperature of 400 ° C. or less, preferably 350 to 390 ° C., and a hydrogen pressure of 100 kg / cm ² G or more, preferably 120 to 150 kg / cm ^2. This is a step of highly hydrotreating using a hydrogenation catalyst under the conditions of G. The hydrogenation catalyst used in this hydrogenation process is mainly for the purpose of hydrogenation of aromatic nuclei, and the degree of hydrogenation is the rate of decrease in hexane-insoluble and benzene-soluble components (hereinafter referred to as HI-BS components). Is 90% by weight or more, preferably 95 to 100% by weight. The decomposition rate [f (I)] (hereinafter, also simply referred to as the decomposition rate) of the fraction having a boiling point of 540 ° C. or higher in the heavy oil in the first-stage hydrotreating step is 10% or less, and is usually 10% or less. 5
It is in the range of ~ 10%.

The HI-BS component reduction rate R and decomposition rate F (I) referred to in this specification are defined by the following equations.

A: wt% of HI-BS component in heavy oil B: wt% of HI-BS component in hydrogenated oil C: weight% of the fraction having a boiling point of 540 ° C. or higher in the raw heavy oil D: weight% of the fraction having a boiling point of 540 ° C. or higher in the first hydrogenation product oil The hydrogenation catalyst used in the first hydrotreating step Is a porous carrier that supports a metal such as V, Mo, W, Ni, Co, Pd, Pt, Re, Ru, and Rh. In particular, Ni-Co-Mo, Ni
It is preferable to use one carrying a combination such as -Mo. As the porous carrier, various carriers such as alumina, silica, titania, alumina silica, alumina titania, alumina zirconia, and silica magnesia are used. Preferred carriers are alumina, titania and the like. The supported metal is usually present on the support in oxide and / or sulfide form. As the catalyst used in this hydrotreating step, one having an average pore diameter of 150 ° or more is used.

(Second Hydrotreating Step) In this step, the hydrogenated oil obtained in the first hydrotreating step is treated at a temperature of 400 to 460 ° C, preferably 430 to 450 ° C, and a hydrogen pressure of 80 kg / cm ² G or more, Preferably, it is a step of hydrotreating using a hydrogenation catalyst under a condition of 100 kg / cm ² G or more. The main purpose of this hydrotreating step is to hydrocrack the first hydrogenated oil, and as described above, the reaction temperature is higher than that of the first hydrotreating step. Decomposition rate f (II) in the second hydrotreating step
Is usually 60 to 80%, and the total decomposition rate f (T) is usually
70-90%. Note that the decomposition rate f (II) and the total decomposition rate f
(T) is defined by the following equation.

E: Weight% of the fraction having a boiling point of 540 ° C or higher in the second hydrogenated oil As the second hydrotreating catalyst, one having the same properties as those shown in the first hydrogenation step, that is, as a porous carrier, alumina, silica, titania, alumina silica, alumina titania, alumina zirconia, silica Various materials such as magnesia are used, and V, M
A catalyst having a large pore diameter of 150 ° or more in average pore diameter using a metal such as o, W, Ni, and Co is used. As a particularly preferred catalyst, Ni-Mo, silica-alumina supporting Ni-W, or the like is used as a supported metal.

In the second hydrotreating step, it is preferable to add 2 to 20% by weight of an aromatic oil to the reaction solution in order to increase the total decomposition rate and prevent sludge formation. As the aromatic oil, an aromatic compound having a boiling point of 200 to 400 ° C. (for example, methylnaphthalene, naphthalene, ethylnaphthalene, propylnaphthalene, or the like) or at least 50
% By weight.

(Effects of the Invention) According to the present invention, heavy oil is highly hydrogenated in a first hydrotreating step using a large pore diameter catalyst and then hydrocracked, so that sludge generation is avoided. To hydrocrack heavy oil to a high degree. The product (lightened hydrocarbon oil) obtained in the present invention is of high quality, substantially free of sludge, and has good stability.

(Example) Next, the present invention will be described in more detail with reference to examples.

Example A vacuum residue of Arabian light crude oil was used as a raw material heavy oil. This vacuum residue oil was composed of 91% by weight of a hexane-soluble (HS) component, 9% by weight of a hexane-insoluble and benzene-soluble (HI-BS) component, and 0% by weight of a benzene-insoluble (BI) component. Was. The ratio of the fraction having a boiling point of 540 ° C. or higher was 95% by weight.

10 parts by weight of this raw material oil was placed in an autoclave, 1 part by weight of a hydrotreating catalyst was added, and the temperature was 390 ° C. and the hydrogen pressure was 150 kg.
The reaction was carried out at / cm ² G for 3 hours. Table 1 shows the results of the reaction.

The hydrogenation catalyst used in this hydrotreating step was Ni
A silica-alumina catalyst containing 1.0% by weight of O and 5.0% by weight of MoO ₃ , having a specific surface area of 147 m ² / g, a specific pore volume of 0.71 ml / g and an average pore diameter of 168 °. This was preliminarily sulfurized at 360 ° C. for 6 hours using hydrogen gas containing 5% H ₂ S before use.

Next, 10 parts by weight of the hydrogenated oil obtained above was placed in an autoclave, 1 part by weight of the same hydrogenation catalyst as described above was added, and the temperature was 420 ° C. and the hydrogen pressure was 150 kg / cm ² G. The reaction was performed for one hour. Table 1 shows the results of the reaction.

Example 2 An experiment was performed in the same manner as in Example 1, except that the reaction time in the second hydrotreating step was changed to 3 hours. As a result, a result of a total decomposition rate [f (T)] of 70% was obtained.
In this case, the generation of sludge in the produced oil was extremely small, but the quality of the produced oil was judged to be good.

Example 3 An experiment was carried out in the same manner as in Example 1 except that the temperature in the second hydrotreating step was 440 ° C., and 10% by weight of 1-methylnaphthalene was added to the first hydrogenated oil. As a result, a result of a total decomposition rate [f (T)] of 81% was obtained, and substantially no sludge was found in the produced oil.

Comparative Example 1 10 parts by weight of the raw material heavy oil shown in Example 1 was placed in an autoclave, 1 part by weight of the catalyst shown in Example 1 was added, and the reaction temperature was 420 ° C., and the hydrogen pressure was 150 kg / cm ² G. A time reaction was performed. As a result, a decomposition rate of 74% was obtained. In this case, a large amount of sludge was generated.

Comparative Example 2 In Example 1, an alumina catalyst containing 3.1% by weight of NiO and 15% by weight of MoO ₃ was used as a catalyst in the first and second hydrotreating steps. The specific surface area was 273 m ² / g, Pore volume 0.
An experiment was performed in the same manner except that a material having a property of 52 ml / g and an average pore diameter of 100 ° or less was preliminarily sulfurized at 360 ° C. for 6 hours using hydrogen gas containing 5% H ₂ S. . As a result, a result of a total decomposition rate [f (T)] of 63% was obtained. In this case, a large amount of sludge was generated.

Claims (1)

(57) [Claims] 1. A petroleum heavy oil is subjected to a two-stage hydrogenation treatment using a large pore diameter hydrogenation catalyst having an average pore diameter of 150 ° or more. 400
At a hydrogen pressure of 100 kg / cm ² G or more, a benzene-insoluble fraction of benzene-soluble components reduced by 90% or more and a boiling point of 540 ° C or more at a decomposition rate of 10% or less. The hydrotreating step is performed at a temperature of 400 to 460 ° C, hydrogen pressure of 80 kg / cm ² G or more and a boiling point of 540 ° C or more.
A two-stage hydrocracking method for petroleum heavy oil, characterized in that a hydrocracking product oil containing substantially no sludge is obtained.