JP2986838B2 - Hydrotreatment of residual oil - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a hydrotreating method for removing sulfur, nitrogen and metals such as nickel and vanadium contained in a residual oil, and particularly to a high desulfurization method. This is a method for hydrotreating a residual oil that can obtain a high boiling point fraction and improve the product stability of the produced high-boiling fraction.

[Prior art] As a recent oil trend, imported crude oil tends to be heavier. Therefore, after removing the useful light fraction, a large amount of the heavy fraction, especially the residual oil, is by-produced. Therefore, treating this residual oil is an important problem. This residual oil has a very high concentration due to the concentration of sulfur, nitrogen and metal. There are hydrocracking, fluid catalytic cracking, etc. as methods for treating and reducing residual oil.However, if residual oil containing a high concentration of sulfur, nitrogen and metal is used as a raw material as it is, It causes reduction or catalyst poisoning, and furthermore, the sulfur and nitrogen contents are a source of air pollution.

Therefore, a method of removing sulfur, nitrogen or metal by hydrotreating the residual oil is becoming increasingly important. Hydrotreating is a method of catalytically treating a feedstock under hydrogen pressure and converting sulfur and nitrogen in the feedstock to hydrogen sulfide, ammonia, etc., or removing metal by depositing in a catalyst. It is. Conventionally, indirect desulfurization has mainly involved the treatment of vacuum gas oil, and the amount of metal in the feedstock oil has been small.
However, with recent heavy crude oil worldwide,
Metal components such as sulfur, nickel, and vanadium contained in crude oil have been increased, and direct desulfurization of residual oil has been actively performed in the process.

By the way, sulfur contained in a large amount in residual oil is not easily desulfurized, and a high reaction temperature is required to achieve a high desulfurization rate. However, it is known that when the reaction temperature is increased, coke is easily generated. ing. Another problem is the clogging of the catalyst pores by metal and coke, which necessitates increasing the reaction temperature to compensate for the decrease in catalyst activity, which hinders the operation of the apparatus. Therefore, in order to perform stable operation, it is necessary to use a hydrotreating method that can efficiently remove sulfur and metals contained in the feedstock oil, maintain the activity for a long period of time, and provide a product with good stability. Development is required.

[Problems to be Solved by the Invention] Residual oil contains a large amount of metals such as vanadium and nickel, and also contains large molecules such as asphaltenes.
This causes coke generation. The active points on the catalyst are covered by the metal component and the generated coke, and the pores are blocked, so that the catalyst is easily deteriorated and its life is shortened.

Therefore, the reaction temperature is usually set high to improve the desulfurization rate and the decomposition rate, thereby improving the decomposition rate, desulfurization rate, denitrification rate, demetallization rate, and the like. However, it is known that the properties of the product obtained at that time, in particular, the properties of the fraction having a boiling point of 360 ° C. or more deteriorate. In other words, this fraction is liable to form sludge and causes trouble during operation, transportation, storage, or the like. As for the sludge, as a quantification method, a toluene insoluble content is measured. If this is 0.05 wt% or less, preferably 0.03 wt% or less, there is no problem. When a high decomposition rate is obtained at a high temperature using an ordinary catalyst, for example, when the decomposition rate is 50 to 60%, the toluene-insoluble content may be 0.1 wt%.

Whether or not the product properties of the fraction are good depends mainly on the toluene-insoluble matter, and the more toluene-insoluble matter, the more unfavorable as a product. Therefore, in order to carry out the hydrotreating of heavy oil, it is necessary to develop a hydrotreating method capable of obtaining a high desulfurization rate even at a low reaction temperature and giving favorable product properties.

[Means for Solving the Problems] The present inventors have conducted intensive studies in order to solve the above problems, and as a result, have a predetermined pore structure, a catalyst having a low active metal content and a predetermined pore structure. A hydrotreating method for a residual oil having a high active metal content and a catalyst containing a boron compound and / or a phosphorus compound, and having a high desulfurization activity and a product property of a heavy fraction of the produced oil for a long period of time. I found

That is, the present invention provides an alumina carrier having a composite active metal selected from nickel-molybdenum, cobalt-molybdenum, and nickel-cobalt-molybdenum supported on an alumina carrier in an amount of 1.0 to 7.0 wt% as an oxide, The total surface area measured by the adsorption method is 150 m ² / g or more, the average pore diameter is 100 mm or more, the total pore volume is 0.6 ml / g or more, and the volume occupied by pores having an average pore diameter of 120 to 200 mm is very small. A first layer filled with a catalyst having a pore volume of 75% or more and a composite active metal selected from nickel-molybdenum, cobalt-molybdenum, and a composite active metal selected from nickel-cobalt-molybdenum on an alumina carrier; as a 8.0～15.0Wt% boron compound and / or phosphorus compounds and 0.5～10.0Wt% supported oxide becomes, the total surface area measured by nitrogen adsorption method 150 meters ² / g or more, an average pore Diameter 1
A reaction section comprising a second layer filled with a catalyst having a volume of at least 00%, a total pore volume of at least 0.5 ml / g, and an average pore diameter of 100 to 200 mm occupying 75% or more of the total pore volume. Accordingly, the present invention provides a method for hydrotreating residual oil, wherein the residual oil is hydrotreated at a hydrogen pressure of 100 kg / cm ² or more, an LHSV of 0.1 to 1.0 and a temperature of 300 ° C. or more.

The alumina carrier used in the present invention can be prepared by a known preparation method. For example, an aluminum salt such as aluminum sulfate is neutralized with an alkali such as ammonia or an aluminate such as sodium aluminate, and an appropriate alkali is added to the generated alumina hydrate to form an alumina hydrate slurry. PH is adjusted to 8-10 weak alkaline, 60-15
After aging at 0 ° C. for 1 to 100 hours to produce boehmite, kneading the boehmite and forming it into an arbitrary shape by extrusion or the like,
It is obtained by drying and baking. However, if the maturation is insufficient, the carrier referred to in the present invention may not be obtained. Also, using commercially available boehmite powder,
It can also be obtained by pulverizing with an acid or the like, molding, and then drying and firing.

The composite active metal used in the present invention includes at least one selected from Ni, Co, and Mo, and includes Ni-Mo, Co-Mo, Ni
-Selected from Co-Mo. Other active metals may be included in small amounts. The amount of active metal supported is calculated as metal oxide based on the total weight of the catalyst, and the catalyst of the first layer is 1.0 to
The range of 7.0 wt%, preferably 3.0 to 6.5 wt% is suitable, and the catalyst of the second layer is 8.0 to 15.0 wt%, preferably 10.0 to 14.0 wt%.
%. In the case of a composite, 0.5% to 3.0% by weight of Co and 0.1% of Ni are used.
The range of 5 to 3.0 wt% and Mo of 2.0 to 15.0 wt% are preferred.

In the present invention, the addition amount of the boron compound and / or the phosphorus compound in the catalyst of the second layer is 0.5 to 10.0 wt%, preferably 0.6 to 5.0 wt%, calculated as an oxide based on the total weight of the catalyst. Range. If the amount of the boron compound or the phosphorus compound is less than 0.5% by weight as an oxide, there is no effect, and if the amount exceeds 10.0% by weight, the desulfurization activity of the catalyst does not change much, but the pore diameter is small. Disadvantage. In the catalyst of the present invention, when both the boron compound and the phosphorus compound are contained, the addition ratio of each oxide is preferably 1: 9 to 9: 1 (weight ratio),
More preferably, the ratio is 1: 4 to 4: 1 (weight ratio).

The boron compound used in the present invention may be either an inorganic compound or an organic compound of boron, and can be converted to boron oxide when the catalyst is calcined. For example, boric acid, ammonium borate, orthoboric acid, tetraboric acid, ammonium biborate, diborane, methyl borate, butyl borate, tricyclohexyl borate and the like can be mentioned.

The phosphorus compound used in the present invention may be either an inorganic compound or an organic compound of phosphorus, and can be converted to phosphorus oxide when the catalyst is calcined. For example, phosphoric acid, ammonium phosphate, diammonium phosphate and the like can be mentioned.

The method for supporting the boron compound, the phosphorus compound and the active metal on the alumina carrier according to the present invention is not particularly limited. For example, there are an impregnation method and a coprecipitation method. The order of loading is not limited. For example, each component may be supported separately or simultaneously. Further, two components may be supported first, and the remaining components may be supported later.

The catalyst of the first layer used in the present invention, the total surface area measured by nitrogen adsorption method 150 meters ² / g or more, preferably 150 to 250 ² / g,
The average pore diameter is 100 mm or more, preferably 100 to 300 mm, the total pore volume is 0.6 ml / g or more, preferably 0.6 to 1.0 ml / g, and the volume occupied by pores having an average pore diameter of 120 to 200 mm is It has a pore distribution of 75% or more, preferably 75-85% of the total pore volume. If the total surface area of the catalyst is less than 150 m ² / g, sufficient activity cannot be obtained. If the average pore diameter is less than 100 °, the pores are likely to be blocked and the life is shortened. The total pore volume is 0.
When it is less than 6 ml / g, the amount of metal in the feedstock accumulated on the catalyst is small. In addition, if the volume occupied by pores having an average pore diameter of 120 to 200 mm is a pore distribution of less than 75% of the total pore volume,
The reaction field required for conversion of the molecules in the residual oil is small and the activity is not effectively exhibited.

Further, in the catalyst of the second layer, the total surface area measured by nitrogen adsorption method 150 meters ² / g or more, preferably 150 to 250 ² / g, an average pore diameter of 100Å or more, preferably 100 to 200 Å, a total pore The volume is 0.5 ml / g or more, preferably 0.5 to 1.0 ml / g, and the volume occupied by pores having an average pore diameter of 100 to 200 mm is 75% or more, preferably 75 to 85% of the total pore volume. Has a pore distribution.
If the total surface area of the catalyst is less than 150 m ² / g, sufficient activity cannot be obtained. If the average pore diameter is less than 100 °, the pores are likely to be blocked and the life is shortened. 0.5ml / g total pore volume
When the amount is less than the above, the amount of metal accumulated in the catalyst in the feed oil is small. In addition, if the volume occupied by pores having an average pore diameter of 100 to 200 mm is less than 75% of the total pore volume, the reaction field required for the conversion of molecules in the residual oil is small, and the activity is effectively exhibited. do not do.

In the present invention, a preferred pore structure is shown, and if it is out of this range, for example, if the pore diameter is small, the catalyst life is short and the product properties are not good. The catalyst of the present invention can be used in a desired shape such as a sphere, a tablet or a column. In the present invention, the ratio of the first layer and the second layer is 1: 1 to 1: 4.
(Weight ratio) is preferred.

The reaction conditions employed in the method of the present invention are as follows:
g / cm ² or more, preferably 100~170Kg / cm ^2, the reaction temperature 300 ° C.
Above, preferably 300 ~ 500 ℃, more preferably 350 ~ 4
50 ° C, LHSV 0.1 to 1.0, preferably 0.1 to 0.5, more preferably 0.1 to 0.3, and the hydrogen / feed oil ratio is 100 to 2000 Nl / Nl.

Both the first catalyst layer and the second catalyst layer in the reaction section are fixed beds,
A reaction system such as a moving bed and a fluidized bed can be used. The supply of the raw material to the reaction section may be performed from either the upper part or the lower part of the reactor. That is, either of the upward flow and the downward flow may be used. Further, the first catalyst layer and the second catalyst layer may be provided in separate reactors, or may be provided in the same reactor.

The residual oil referred to in the present invention is an oil containing a large amount of heavy metal components such as vanadium and nickel, and also containing large molecules such as asphaltenes.For example, residual oil obtained by normal pressure or reduced pressure distillation of crude oil, oil Residual oil obtained by normal pressure or reduced pressure distillation of sand oil or tar sands extracted crude oil, or a mixed oil thereof. In the present invention, a vacuum distillation residue is preferably used.

By treating the residual oil using the method of the present invention, the cracking rate is 50-60% and the yield of middle distillate is about 13-20%. The fraction having a boiling point of 360 ° C. or higher has a toluene insoluble content of 0.05% by weight or less.

[Effects of the Invention] As described above, by subjecting a vacuum residue to hydrogenation treatment using the method of the present invention, a product having a high desulfurization rate, a high decomposition rate and favorable properties of the produced oil can be obtained.

[Examples] Next, the present invention will be described in more detail with reference to Examples and the like.

Example of Preparation of Carrier Aluminum hydroxide was prepared from an aqueous solution of aluminum sulfate and an aqueous solution of sodium aluminate, and aged under predetermined conditions. The obtained gel was heated and kneaded, extruded, dried at 110 ° C., and calcined at 550 ° C. to obtain an alumina carrier. In this operation, an alumina support having a different pore structure was obtained by changing the aging conditions. AM-1 is 120 ° C
For 8 hours, AM-2 for 3 hours at 90 ° C, AS-1 for 5 hours at 120 ° C
Time and AS-2 were prepared by aging at 90 ° C. for 1 hour, respectively.

In the following catalyst preparation examples, the concentrations of Mo, Co, Ni, P and B were determined by using oxides (MoO ₃ , CoO, NiO, P ₂ O ₅ and
B ₂ O ₃ ).

Catalyst Preparation Example 1 The carrier AM-1 was impregnated with an aqueous solution containing 5.0 wt% of Mo, 1.1 wt% of Co, and 10.0 wt% of citric acid by a pore filling method. The carrier is left to dry, then dried at 110 ° C.
Fired at 50 ° C. The obtained catalyst was designated as HM-1.

Catalyst Preparation Example 2 A carrier AS-1 was impregnated with an aqueous solution containing 10.2 wt% of Mo, 2.2 wt% of Ni, 5.0 wt% of P, and 15.0 wt% of citric acid by a pore filling method. After leaving the carrier to dry, 11
Dried at 0 ° C and calcined at 550 ° C. The resulting catalyst was HS-1
And

Catalyst Preparation Example 3 An aqueous solution containing 10.1 wt% of Mo, 2.1 wt% of Ni, 5.0 wt% of B, and 15.0 wt% of citric acid was impregnated into the support AS-1 by a pore filling method. After leaving the carrier to dry, 11
Dried at 0 ° C and calcined at 550 ° C. The resulting catalyst was HS-2
And

Catalyst Preparation Example 4 The carrier AM-2 was impregnated with an aqueous solution containing 5.0 wt% of Mo, 1.0 wt% of Co, and 10.0 wt% of citric acid by a pore filling method. The carrier is left to dry, then dried at 110 ° C.
Fired at 50 ° C. The obtained catalyst was designated as HM-2.

Catalyst Preparation Example 5 The carrier AS-1 was impregnated with an aqueous solution containing 10.1 wt% of Mo, 2.2 wt% of Ni, and 15.0 wt% of citric acid by a pore filling method. After the carrier was left to dry, it was dried at 110 ° C and calcined at 550 ° C. The resulting catalyst was designated as HS-3.

Catalyst Preparation Example 6 The carrier AS-2 was impregnated with an aqueous solution containing 10.2 wt% of Mo, 2.1 wt% of Ni, and 15.0 wt% of citric acid by a pore filling method. After the carrier was left to dry, it was dried at 110 ° C and calcined at 550 ° C. The obtained catalyst was designated as HS-4.

Table 1 summarizes the properties of the catalyst prepared as described above.

* 1: HM-1 and HM-2 are volume ratios with pore diameters of 120 to 200 mm, HS
-1, HS-2, HS-3, and HS-4 are volume ratios of pore diameters of 100 to 200 mm.

Examples 1 and 2 and Comparative Examples 1 to 3 (Evaluation Examples) The catalysts prepared in Catalyst Preparation Examples 1 to 6 were respectively combined, and the first layer and the second layer were each in a ratio of 1: 2 (weight ratio). After filling in a microreactor having an inner diameter of 200 mmφ, the vacuum residue having the properties shown in Table 2 was hydrogenated after sulfuration.

Table 3 summarizes the results of the reaction under the following predetermined conditions. The reaction conditions were as follows: reaction temperature 400 ° C, L
HSV 0.2, pressure 115 kg / cm ² , hydrogen / oil 700 Nl / Nl.

* 2: Ratio of fraction below 170 ° C to feedstock, * 3: Ratio of fraction from 170 to 360 ° C to feedstock, * 4: Toluene insolubles in fraction above 360 ° C, see Table 3. As shown, Examples 1-2 are Comparative Examples 1-2.
As compared with No. 3, the desulfurization rate and the demetalization rate are excellent, and the yield of the middle distillate is also high. Moreover, despite the high conversion, the toluene-insoluble content of the high boiling point fraction was small, and it was preferable as a product.

FIG. 1 shows the change in the rise of the reaction temperature for keeping the desulfurization rate constant. Here, the critical reaction temperature is the maximum temperature for obtaining a good product. That is, above this temperature, the operation cannot be performed because the product stability is deteriorated.

As shown in FIG. 1, in the method of the present invention, since the time required to reach the limit reaction temperature is long, the apparatus can be operated for a longer time, thereby providing a great advantage.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the relationship between operating time and reaction temperature in Examples and Comparative Examples.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10G 45/06 C10G 45/06 A 45/08 45/08 A (72) Inventor Yasuhiro Kubota 8 Chidoricho, Naka-ku, Yokohama-shi, Kanagawa Address Japan Central Oil Research Institute (72) Kazuo Shimizu, Inventor Kazuo Shimizu 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Japan Petroleum Corporation Central Technology Research Institute (72) Tadakazu Yamashita 8, Chidori-cho, Naka-ku, Yokohama, Kanagawa Address: Japan Petroleum Co., Ltd. Central Research Laboratory (72) Inventor Akira Inoue 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Japan Petroleum Co., Ltd. Central Research Laboratory (56) References JP-A-2-35938 (JP, A) JP-A-59-150537 (JP, A) JP-A-55-18499 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C10G 45/04-45/08

Claims (1)

(57) [Claims] 1. An alumina carrier having a composite active metal selected from the group consisting of nickel-molybdenum, cobalt-molybdenum and nickel-cobalt-molybdenum supported as an oxide in an amount of 1.0 to 7.0% by weight based on the total weight of the catalyst. The total surface area measured by the method is 150 m ² / g or more, and the average pore diameter is 100 mm
As described above, the total pore volume is 0.6 ml / g or more, and the average pore diameter is 1
A composite layer selected from nickel-molybdenum, cobalt-molybdenum, and nickel-cobalt-molybdenum on a first layer filled with a catalyst in which the volume occupied by pores of 20 to 200 ° is at least 75% of the total pore volume; 8.0-15.0 wt% based on the total weight of the catalyst, based on the active metal as an oxide, and 0.5-10.0 wt% of a boron compound and / or a phosphorus compound as an oxide, and the total surface area measured by a nitrogen adsorption method is 150 m. ² / g or more, average pore diameter is 100 mm or more, total pore volume is 0.5 ml / g or more, and the volume occupied by pores having an average pore diameter of 100 to 200 mm is at least 75% of the total pore volume the reaction unit consisting of the second layer of filled, the hydrogen pressure 100 kg / cm ² or more, LHSV0.1～1.0, temperature 300
A method for hydrotreating residual oil, the method comprising hydrotreating residual oil at a temperature of not less than ° C.