JPH0593190A - Hydrogenation of residual oil - Google Patents

Abstract

PURPOSE:To obtain a high-boiling oil having stable properties, a high degree of desulfurization, a high degree of demetalling and a high yield of a middle fraction. CONSTITUTION:A residual oil is hydrogenated under the conditions of a hydrogen pressure of 90kg/cm<2> or above, a temperature of 300-500 deg.C and an LHSV of 0.1-1 in the presence of a catalyst layer comprising a first layer packed with 10-50%, based on the total amount of the catalyst in the reaction tower, catalyst prepared by impregnating an alumina carrier with 1-7wt.% (in terms of the oxide) at least one metal selected from among Ni, Co, Mo, V and W and 0.5-5wt.% (in terms of the oxide) boron compound having a total surface area of at least 100m<2>/g, a total pore volume of at least 0.5ml/g and a volume occupied by pores of average pore diameters of 120-200Angstrom of at least 70% based on the total pore volume when measured by the nitrogen adsorption method and a second layer packed with 50-90wt.%, based on the whole catalyst layer, hydrogenation catalyst.

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 a residual oil containing a large amount of sulfur, nitrogen and metals such as nickel and vanadium. Desulfurization rate, especially over long periods of time
Hydrotreatment that can maintain high demetallization rate and middle distillate (distillate at 170-360 ° C) yield, and can obtain high boiling point product oil with stable properties (low toluene insoluble content) Regarding the method.

[0002]

2. Description of the Related Art While crude oil produced is becoming heavier, the demand for light distillates continues to increase. Therefore, it is an important problem to treat the heavy fraction after removing the useful light fraction, especially the residual oil. Since residual oil is concentrated in sulfur, nitrogen and metals, they are present in extremely high concentrations. When lightening the residual oil, treatment means such as hydrocracking and fluid catalytic cracking are adopted, but when the residual oil containing high concentrations of sulfur, nitrogen and metal is directly treated, Not only is it impossible to obtain a quality product, but there is also the problem that the catalyst is poisoned by sulfur, nitrogen, metal components, and the like.

Therefore, in lightening the residual oil,
It is important to remove the sulfur content, nitrogen content or metal content by subjecting the residual oil to hydrogenation treatment in advance. What is hydrotreating? The feedstock is catalytically treated under hydrogen pressure, and the sulfur content and nitrogen content in the feedstock are converted into hydrogen sulfide and ammonia for removal, and the metal content is deposited and removed in the catalyst. Is the way. Conventionally, the feedstock that has been the object of indirect desulfurization is mainly vacuum gas oil, and since the feedstock contains a small amount of metals and asphaltene, no significant problems have occurred. However, when the residual oil is directly subjected to hydrotreatment, there are the following problems.

That is, the residual oil contains a large amount of metal components such as vanadium and nickel, and also contains components having a large molecular weight such as asphaltene, which causes coke formation. These metal components and generated coke mask the active sites of the catalyst or block the catalyst pores, which causes the activity of the catalyst to decrease and the life to shorten. Incidentally, a decrease in catalytic activity leads to a decrease in desulfurization rate and decomposition rate, but in order to compensate for this, conventionally, the reaction temperature is usually increased. However, there is a limit to the increase of the reaction temperature in the operation of the apparatus, and there is a disadvantage that the increase of the reaction temperature promotes the production of coke. In addition to this,
The use of high reaction temperatures has the drawback of degrading the properties of hydrotreated products, especially those with boiling points above 360 ° C.
The fraction generally tends to generate sludge, but if the property deteriorates, the tendency is further increased, and during transportation or storage of the fraction, or after treatment of the fraction,
It causes trouble.

The degree of easiness of sludge formation is 360 ° C.
Evaluated by measuring the amount of toluene insoluble in the fraction having a boiling point above, the amount is 0.05 wt% or less, preferably
If it is 0.03% or less, there is no problem. That is, the quality of the fraction is determined by the amount of toluene insoluble matter, and the more toluene insoluble matter is, the less preferable the product is. When the residual oil is hydrotreated at a relatively high temperature using a conventional ordinary catalyst, the toluene insoluble content of the above-mentioned fraction obtained as a product is 0 at a decomposition rate of the residual oil of about 50 to 60%.
It is not unusual for it to be 1 wt%.

[0006]

DISCLOSURE OF THE INVENTION The present invention stably produces a high boiling point oil having good properties with less sludge formation from a residual oil containing a large amount of sulfur, nitrogen and metals such as nickel and vanadium. The purpose is to get. Further, the present invention has a high desulfurization rate for a long time even if the reaction conditions are mild,
The purpose of the present invention is to establish a hydrotreating method capable of obtaining a metal removal rate and a middle distillate yield.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that a catalyst having a specific pore structure and supporting a specific metal component is usually prepared. By using it in the hydrotreatment of residual oil in combination with the above hydrogenation catalyst, a high boiling point product oil with good properties can be obtained while maintaining a high desulfurization rate, demetalization rate and middle distillate yield over a long period of time. I found that I can be.

Therefore, in the hydrotreating method according to the present invention, 1 to 7 wt% (as an oxide) of at least one active metal selected from nickel, cobalt, molybdenum, vanadium and tungsten and 0.5% of a boron compound are used.
~ 5 wt% (as oxide) supported on alumina support and has a total surface area of at least 100 m ^{2 as} measured by nitrogen adsorption method
/ G, the total pore volume is at least 0.5 ml / g, and the volume occupied by pores with an average pore diameter of 120 to 200 angstroms is at least 70% of the total pore volume, and In the presence of a catalyst layer consisting of a first layer filled with 10 to 50% and a second layer filled with 50 to 90% of the total hydrotreating catalyst, the residual oil has a hydrogen pressure of 90 kg / cm ² or more, Temperature 300 ~
It is characterized in that hydrogenation is carried out under the conditions of 500 ° C. and LHSV 0.1 to 1. In the present invention, the alumina carrier of the catalyst used in the first layer of the catalyst layer can be prepared by a known 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 produced alumina hydrate to prepare an alumina hydrate slurry.
Adjust the pH to a weak alkaline of 8-10 and set it to 60-150 ° C for 1
The desired alumina carrier can be produced by aging for about 100 hours to form boehmite, kneading the boehmite into a desired shape by extrusion molding or the like, and then drying and firing. It is preferable that the above-mentioned aging is sufficiently performed. Alternatively, it is also possible to adopt a method in which commercially available boehmite powder is peptized with an acid or the like, and molded, dried and fired.

The active metal supported on the alumina carrier is N
At least one selected from i, Co, W, Mo, V,
When compounding active metals, Ni-Mo, Co-Mo, Ni-Co-Mo, N
There are combinations of iW, Co-W, Ni-Co-W, Ni-V, Co-V, Co-V-Mo, etc. Preferred combinations include Co-Mo, Ni-Mo, Ni-Co-Mo, C
Examples include oW and Ni-W. A small amount of active metals other than the above may be contained in the carrier. The amount of the active metal supported is in the range of 1 to 7 wt%, preferably 3 to 6.5 wt% of the total weight of the catalyst in terms of metal oxide. When the active metals are combined, the ratio of the active metals can be arbitrarily selected.

A boron compound is supported on the alumina carrier in addition to the above-mentioned active metal, and the supported amount thereof is 0.5 to 5 wt% of the total weight of the catalyst in terms of oxide, preferably 0.6 to.
It is in the range of 4.5 wt%. If the supported amount of the boron compound is less than 0.5 Ww% as an oxide, there is no effect, and even if the supported amount exceeds 5 wt%, the desulfurization activity of the catalyst does not change much,
On the contrary, there is a drawback that the pore diameter becomes small.

The boron compound used in the present invention may be either an inorganic compound or an organic compound as long as it is a compound which can be converted into 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, etc. can all be used.

The method of supporting the boron compound and the active metal component on the alumina carrier is not particularly limited, and for example, an impregnation method, a coprecipitation method or the like can be adopted. The loading order is also arbitrary, and the respective components can be loaded individually or simultaneously. Further, the components thereof may be carried twice or more.

In the present invention, in terms of pore characteristics of the catalyst packed in the first layer of the catalyst layer, the catalyst has a surface area of at least 100 m ² / g, preferably measured by a nitrogen adsorption method. It is in the range of 120 to 250 m ² / g, and the average pore diameter is 100 angstroms or more, preferably 120 to 300.
In the Angstrom range with a total pore volume of 0.5 ml /
g or more, preferably 0.5 to 1 ml / g. The volume occupied by pores having an average pore diameter of 120 to 200 angstrom is at least 70% or more, preferably 70 to 90% of the total pore volume. Surface area of catalyst is 100 m
If it is less than ² / g, sufficient activity cannot be obtained. If the average pore diameter is less than 120 angstrom, the pores are likely to be clogged and the catalyst life is shortened. Total pore volume is 0.5 ml /
If it is less than g, the demetallizing activity of the catalyst is insufficient. Moreover, in the pore distribution in which the volume occupied by pores having an average pore diameter of 120 to 200 angstrom is less than 70% of the total pore volume,
Since there are few reaction sites that contribute to the conversion of molecules in the residual oil,
Satisfactory catalytic activity cannot be expected. The shape of the catalyst to be filled in the first layer can be arbitrarily selected, and for example, a spherical shape, a tablet shape, a cylindrical shape or the like can be appropriately selected.

The second layer of the catalyst layer is filled with a conventional hydrotreating catalyst. As used herein, the conventional hydrotreatment catalyst means a catalyst that is commonly used in the hydrotreating of residual oil in the art. For example, on an oxide carrier such as alumina,
A catalyst supporting one or more kinds of active metals such as molybdenum, tungsten, nickel, cobalt, vanadium, etc. in the range of 1 to 10 wt% and having a surface area of at least 100 m ² / when measured by a nitrogen adsorption method. g, total pore volume
Included in the catalyst used in the second layer is a catalyst having 0.4 ml / g or more and an average pore diameter of 100 Å or more.

In carrying out the method of the present invention, the catalyst filling ratio in the first layer in the reaction tower is 10% of the total catalyst layer volume.
-50%, preferably 20-40%. When it is out of this range, the catalyst life as a whole becomes short, and the desulfurization rate and demetalization rate also decrease. Further, the catalyst filling ratio in the second layer in the reaction tower is 50 to 90% of the total catalyst layer volume, preferably
60-80%. In the present invention, the first layer means the inlet side of the reaction tower, and the second layer means the outlet side of the reaction tower. The catalyst of the first layer and the catalyst of the second layer may be packed in the same reaction tower or may be packed in different reaction towers. What is the total catalyst bed volume when packed in separate reaction towers?
It refers to the total volume of the catalyst layers of the individual reaction towers. The first catalyst layer and the second catalyst layer can be operated in any reaction system of a fixed bed, a moving bed and a fluidized bed. However, the catalysts of the first catalyst layer and the second catalyst layer are not mixed.

The hydrotreating condition of the present invention is a reaction pressure of 90 kg.
/ Cm ² or more, preferably 110 to 250 kg / cm ² , reaction temperature 30
0 to 500 ° C, preferably 350 to 450 ° C, LHSV0.1
-1, preferably 0.1-0.5, hydrogen / feed oil ratio 100-20
It is in the range of 00 Nl / Nl. If the reaction pressure is less than 90 kg / cm ² , the desulfurization rate and demetallization rate will decrease, and the properties of the produced oil will deteriorate. If the reaction temperature is less than 300 ° C, sufficient desulfurization rate and demetallization rate cannot be obtained, and if it exceeds 500 ° C, the properties of the produced oil decrease and the production of coke increases. Is a problem. When LHSV is less than 0.1, the catalyst deteriorates rapidly, and when it exceeds 1, sufficient desulfurization rate and demetalization rate cannot be obtained.

The residual oil to be hydrotreated in the present invention refers to an oil containing a large amount of heavy metal components such as vanadium and nickel and also containing a large molecule such as asphaltene. Typical examples of the oil to be treated in the present invention are residual oil obtained by atmospheric distillation or reduced pressure distillation, oil sand oil, and residual oil of tar sand extracted crude oil at atmospheric pressure or reduced pressure.

According to the hydrotreating method of the present invention, 50 to 60
%, The middle distillate can be recovered in a yield of about 15 to 20%, and the toluene insoluble fraction having a boiling point of 360 ° C or higher can be reduced to 0.05 wt% or less. ..

[0019]

EFFECTS OF THE INVENTION The hydrotreating method of the present invention exhibits a high desulfurization rate, demetalization rate and intermediate fraction (distillate at 170 to 360 ° C.) yield over a long period of time even under mild reaction conditions. Further, despite the high decomposition rate, it is possible to obtain a high boiling point product oil having good properties (toluene insoluble content is small) from the residual oil.

[0020]

EXAMPLES The present invention will be described in more detail by way of examples. 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 gel obtained was kneaded by heating, extrusion-molded, dried at 110 ° C., and calcined at 550 ° C. to obtain an alumina carrier. By changing the aging conditions with this operation,
Three types of alumina supports S-1 to S- with different pore characteristics
Got 3

Catalyst Preparation 1 5.0% Mo, 1.2% Co, 3.5% boric acid, citric acid
The carrier S-1 was impregnated with an aqueous solution containing 10.0% by the pore filling method. Then, after leaving the carrier to dry
It was dried at 110 ° C and calcined at 550 ° C. DM the obtained catalyst
-1.

Catalyst Preparation 2 5.0% Mo, 1.2% Co, 3.5% boric acid, citric acid
The carrier S-1 was impregnated with an aqueous solution containing 10.0% by the pore filling method. The carrier was left to dry, then dried at 110 ° C and calcined at 550 ° C. The obtained catalyst is designated as DM-2.

Catalyst Preparation 3 A carrier S-2 was impregnated with an aqueous solution containing 5.5% Mo, 1.4% Co and 10.0% citric acid by the pore filling method. The carrier was left to dry, then dried at 110 ° C and calcined at 550 ° C. The obtained catalyst is designated as DM-3.

Catalyst Preparation 4 A carrier S-3 was impregnated with an aqueous solution containing 10.7% Mo, 2.8% Co and 15.0% citric acid by the pore filling method. The carrier was left to dry, then dried at 110 ° C and calcined at 550 ° C. The obtained catalyst is called hydrotreating catalyst DS-1. Table 1 shows the properties of each catalyst prepared as described above.

Example 1, Comparative Examples 1 and 2 (Evaluation Example) The catalysts shown in Table 1 were combined, and any one of DM-1, 2, and 3 was used for the first layer of the catalyst layer and DS-1 was used for the second layer. In each case, the volume ratio is 1: 2
Then, after filling in a microreactor with an inner diameter of 200 mm and sulfiding, the vacuum residue with the properties shown in Table 2 was used at a reaction temperature of 400 ° C and L
When the hydrogenation was carried out under the conditions of HSV 0.2, pressure 115 kg / cm 2, hydrogen / oil 700 Nl / Nl, the results shown in Table 3 were obtained.

As is clear from the results shown in Table 3. Experiment No. 1 according to the method of the present invention is superior in desulfurization rate and demetallization rate and also has a high yield of middle distillate, as compared with Experiment Nos. 2 and 3 of Comparative Examples. Further, despite the high conversion, the toluene-insoluble content of the high boiling point fraction was small, which was a preferable product.

Further, only the reaction temperature is changed so that the target desulfurization rate is maintained at about 80%, and the hydrogenation treatment similar to the above is carried out, so that the reaction temperature required for maintaining the target desulfurization rate. Fig. 1 shows the relationship between the degree of increase in the temperature and the operating time.
The critical reaction temperature shown in FIG. 1 is the maximum temperature for obtaining a good product, and above this temperature, the stability of the product deteriorates and the operation cannot be continued. It can be seen from FIG. 1 that the method of the present invention has an advantage that the apparatus can be operated for a longer time because the operation time until the critical reaction temperature is reached is long.

[0028]

[Table 1] Properties of catalystCatalyst DM-1 DM-2 DM-3 DM-4  Carrier S-1 S-2 S-1 S-3 MoO₃ wt% 5.0 5.0 5.1 10.1 CoO wt% 1.1 1.0 1.0 2.1 B₂ O₃ wt% 3.0 3.0 0 0 Surface area m₂/ G 175 220 173 175 Total pore volume ml / g 0.72 0.65 0.72 0.62 Specific pore% 74 65 74 70Volume ratio Note) The volume ratios in the table are for pore diameters of 120 to 200 angstroms.
The volume of the loam pores represents the ratio to the total pore volume.

[0029]

[Table 2] Properties of feedstock 1.02 Sulfur yellow 4.3 wt% Nickel 35 ppm Vanadium 130 ppm Coal residue 15.0 wt%

[0030]

[Table 3]Example Comparative example  1 1 2 Experiment No. 1 2 3 Catalyst 1st layer DM-1 DM-2 DM-3 2nd layer DS-1 DS-1 DS-1 Desulfurization rate% 87.0 86.0 80.6 Ni removal rate% 65.5 63.5 63.8 DeVation rate % 89.7 84.4 87.5 Residual coal% 6.0 6.5 7.3 Decomposition rate wt% 54.0 51.4 52.3 Naphtha, etc. wt% 4.5 3.5 3.8 Middle distillate wt% 16.5 14.2 13.1Insoluble matter wt% 0.03 0.06 0.05  Note) “Naphtha, etc.” in the table refers to the fraction with a boiling point of 170 ° C or less.
"Intermediate fraction" is a fraction with a boiling point of 170-360 ° C,
“Minute” indicates the toluene insoluble fraction of the fraction with a boiling point of 360 ° C.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the operating time of hydrotreating and the degree of increase in reaction temperature required to maintain a target desulfurization rate.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Taichi Yamashita 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Central Research Institute of Nippon Oil Oil Co., Ltd. (72) Kazuo Shimizu 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Central Research Institute of Nippon Oil Co., Ltd.

Claims (1)

[Claims] 1. An alumina carrier containing 1 to 7 wt% (as an oxide) of at least one active metal selected from nickel, cobalt, molybdenum, vanadium and tungsten.
And a boron compound supported by 0.5 to 5 wt% (as oxide), and the total surface area measured by nitrogen adsorption method is at least 100 m 2 / g, the total pore volume is at least 0.5 ml / g,
A first layer in which 10 to 50% of the total catalyst layer in the reaction column is filled with a catalyst in which the volume occupied by pores having an average pore diameter of 120 to 200 angstrom is at least 70% of the total pore volume, and a hydrogenation treatment Hydrogenation of residual oil under conditions of hydrogen pressure 90 kg / cm ² or more, temperature 300 to 500, LHSV 0.1 to 1 in the presence of a catalyst layer consisting of a second layer filled with 50 to 90% of the total catalyst layer. A method for hydrotreating residual oil, comprising: