JP2672348B2 - Catalyst for heavy oil hydrotreating - Google Patents

Description

TECHNICAL FIELD The present invention relates to a hydrotreating catalyst for performing desulfurization, demetalization, denitrification, decarburization or cracking of heavy oil under hydrogen pressure. .

[Prior Art] Heavy oil such as straight-run, cracked heavy oil, natural bitumen, shale oil, and coal-based heavy oil is important as an energy source. Energy use is extremely important for effective use of energy.

However, heavy oil contains sulfur, nitrogen and metals, which not only cause air pollution when burned but also become a catalyst poison in the oil refining process, so these must be removed in advance. I won't. A hydrotreating method is well known as a method for removing these impurities.

As a catalyst for hydrotreating heavy oil, a porous refractory carrier is selected from Group VIb and Group VIII of the periodic table.
Those carrying more than one metal component are used. In particular, a catalyst supporting a metal component such as molybdenum-cobalt, molybdenum-nickel, or molybdenum-cobalt-nickel has a high initial activity such as desulfurization, denitrification, and decomposition, and thus is used as a catalyst for hydrodesulfurization of heavy oil. Most widely used. However, in this type of catalyst, heavy metals and carbonaceous substances contained in heavy oil adhere to the outer surface of the catalyst, and the desulfurization activity is significantly deteriorated by closing the pores of the catalyst, and the life of the catalyst is short. There was a flaw. In particular, due to the recent trend of diversification of raw materials, heavy oil containing a large amount of nickel and vanadium and having a high content of high molecular weight asphaltene is often used. Preventing catalyst deterioration due to adsorption of substances and extending catalyst life are important issues for effective utilization of heavy oil.

For the above problems, the metal removal performance is enhanced by sacrificing the initial activity to some extent and increasing the metal retention ability.
A catalyst containing any one of Group VIb metal components such as molybdenum is used as a guard catalyst for the desulfurization catalyst, whereby metal in heavy oil is first removed.
Then, the heavy oil from which the metal has been removed is brought into contact with a composite metal oxide catalyst such as molybdenum-cobalt to carry out desulfurization, denitrification, decomposition and the like. This guard catalyst can prevent metal from intensively adhering to the outer surface of the catalyst and prolongs the life of the catalyst, but generally has low activity such as desulfurization, denitrification, and decomposition.

As another measure against the above problem, a catalyst in which the concentration of the active metal in the outer periphery of the catalyst and the concentration of the active metal in the portion susceptible to blockage deterioration due to coke are lowered to increase the concentration distribution of the active metal component toward the center of the catalyst particle It has been proposed (JP-A 61-283351). However, even such a catalyst was not sufficiently satisfactory from the viewpoint of catalyst activity and life. A method using a catalyst carrier having a bidisperse pore distribution of small pore portions (mesopores) and large pore portions (macropores) has also been proposed (JP-A-62-262750), but the same Since small pores and large pores coexist on the catalyst surface, the large pore diameter surface can withstand blockage by heavy metals and coke, but the small pore diameter surface has little durability and is satisfactory from the viewpoint of catalyst life. It cannot be said that it can be done.

[Problems to be Solved by the Invention] As a result of intensive studies conducted by the present inventor to solve the above problems, the catalytic activity is affected by the size of the catalyst pores, but desulfurization, denitrification, and decomposition activities Focusing on the effect of the size of the pores of the catalyst being different between the demetallization and demetallizing activity, the carrier near the center of the catalyst has small pores,
If the support near the outer surface of the catalyst has large pores, the removal rate of the metal can be kept high for a long period of time, the pores of the catalyst are prevented from being blocked, and the heavy oil penetrates well into the catalyst, It has been found that a catalyst having a large activity and small pores can be effectively utilized, and thus the life of desulfurization, denitrification, and decomposition activity can be remarkably extended.

The present invention has been made based on such knowledge to solve the above problems, and an object of the present invention is to prolong the life of desulfurization, denitrification, and decomposition activity for a long time, and to remove metallization activity and decarburization. An object of the present invention is to provide a catalyst which has high activity and can efficiently convert heavy oil into refined oil of excellent quality.

[Means for Solving the Problems] The catalyst of the present invention is a catalyst obtained by supporting a porous refractory inorganic carrier with at least a Group VIb metal component and / or an iron group metal component of the periodic table. The pore volume in and around the center of the is 0.5-0.5 as measured by the BET method.
0.8 ml / g, the pores with a diameter of 50 to 150 Å have a pore distribution of 50 to 90% of the total pore volume with a diameter of 600 Å or less, and the fine particles on the outer surface of the catalyst and in the vicinity thereof. Pore volume is 0.6-1.5 ml / g as measured by BET method, diameter 1
50-600Å pores have a diameter of 600Å or less and 50-90
It is characterized by having a pore distribution of%.

By arranging the catalysts having different pore volumes and pore size distributions in the central portion and the outer surface portion in this manner, the metal removal activity is high, and the poisoning due to the metal adsorption on the catalyst central portion is small, and We have succeeded in obtaining a catalyst for hydrotreating heavy oil, which can maintain a high removal rate of carbonaceous substances for a long period of time and has a long life of desulfurization, denitrification, and cracking activity.

The porous refractory inorganic material used in the present invention may be, for example, those composed of inorganic oxides of Group II, Group III and Group IV elements of the periodic table, in particular, alumina,
It is possible to use oxides of silica, magnesia, thoria, boria, titania, zirconia, and mixtures of two or more thereof. Among these, especially alumina,
Silica-alumina, alumina-magnesia, alumina-
Zirconia, alumina-titania and alumina-boria are preferred, and alumina and silica are particularly preferred. As the alumina, γ-alumina and η-alumina can be preferably used.

In the present invention, the pore volume of the catalyst in the central portion of the catalyst and its vicinity is 0.3 to 1.0 ml / g as measured by the BET method.
The pore size distribution is such that pores having a diameter of 50 to 150Å have 30 to 95%, and γ-alumina and η-alumina are particularly preferable as the carrier used for this purpose.

Also, the pore volume on the outer surface of the catalyst and its vicinity is
The value measured by the BET method is 0.5 to 1.5 ml / g, and the pore size distribution is such that the pores having a diameter of 150 to 600 Å have 30 to 95%, and silica is suitable as a carrier used for this.

The catalyst of the present invention comprises the above-mentioned porous refractory inorganic carrier containing at least a Group VIb metal component and / or an iron group metal component of the Periodic Table, and is suitable as these metal components. It is possible to use molybdenum,
Tungsten, iron, cobalt and nickel, especially molybdenum, cobalt and nickel are most suitable as catalysts for heavy oil hydrotreating. When used in combination of two or more metals, a particularly preferred combination is nickel-
Molybdenum, cobalt-molybdenum, nickel-cobalt-molybdenum.

These metal components are usually supported on the carrier in the form of oxide or metal.

In the present invention, it is preferable that different metal components are contained in the central portion and the vicinity thereof and the outer surface portion and the vicinity thereof, respectively, but the catalyst may be uniformly contained inside and outside. Especially in heavy oil hydrotreating catalysts,
In addition to the means for making the catalyst central volume and its vicinity and the outer surface and its vicinity different in the catalyst pore volume and the pore size distribution, each carrier layer contains a separate metal component. This is an effective method, which can further improve the effects of the present invention.

That is, at least the metal component of Group VIb metal group of the periodic table and the metal component of the iron group having desulfurization, denitrification, and decomposition activity are contained in the central portion of the catalyst and the layer in the vicinity thereof, and the catalyst is applied to the outer surface of the catalyst and its vicinity. By containing a metal component of Group VIb of the periodic table having demetallizing activity, the deterioration of the activity due to the adhesion of heavy metals to the central part of the catalyst and its vicinity is prevented, and the catalyst life is extended.

In this way, in the embodiment in which the catalyst is contained in the central part of the molded body and its vicinity and in the outer surface part of the molded body and its vicinity, the catalyst contained in the central part of the molded body and its vicinity is It is optimal to use at least one of molybdenum and tungsten in combination with one or more of iron, cobalt and nickel. Among these, particularly preferable combinations are nickel-molybdenum, cobalt-molybdenum, and nickel-cobalt-molybdenum.

The content ratio of the metal component of the group VIb and the metal component of the iron group is 0.05-1.
The range of 5, especially 0.1 to 1.0 atom is preferred.

On the other hand, the outer surface of the compact and the first
Molybdenum is particularly excellent as the VIb group metal component.

In the catalyst of the present invention, a plurality of other layers may be provided between the central portion of the molded body and the layer in the vicinity thereof and the outer surface portion and the layer in the vicinity thereof.

Further, in the catalyst of the present invention, the pore volume is 0.5 to 0.8 ml / g as measured by the BET method, and the pores with a diameter of 50 to 150 Å are 50 to 90% of the total pore volume with a diameter of 600 Å or less. The central portion of the catalyst having a certain pore distribution and the layer in the vicinity thereof are 1/5 to 2/3 of the total volume of the catalyst, and the pore volume is 0.6 to 1.5 ml / g as measured by the BET method, The outer surface of the catalyst with a pore distribution in which the pores with a diameter of 150 to 600 Å have a pore distribution of 50 to 90% of the total pore volume with a diameter of 600 Å or less
It is preferably 1/5 to 2/3. When the volume of the catalyst layer in the central portion having a small pore size is small, the initial activity of desulfurization is small,
If the volume of the catalyst layer on the outer surface with a large pore diameter is small, desulfurization activity is reduced due to clogging of the pores of the catalyst due to adhesion of heavy metals and carbonaceous substances to the outer surface of the catalyst, which shortens the life of the catalyst. The object of the present invention cannot be achieved.

Such a catalyst of the present invention can be produced by coating a kneaded material containing a carrier raw material having a small pore diameter with a kneaded material containing a carrier raw material having a large pore diameter, drying and firing.

To prepare a kneaded product of the catalyst carrier, a kneader such as a kneader is used, and water and optionally a deflocculating agent such as a mineral acid or a molding auxiliary is added to the porous refractory inorganic material having a small pore size and kneaded. Then, the first kneaded product is prepared. Next, the surface of the first kneaded material is coated with a second kneaded material made of a porous refractory inorganic material having a large pore size obtained by the same method, dried and fired.

The catalyst component may be kneaded with the carrier raw material in advance,
A supported catalyst containing a catalyst component can be produced by kneading only the carrier raw material or a part of the catalyst component, drying and firing the kneaded product, impregnating the catalyst component, and drying and firing.

A metal component of Group VIb of the periodic table and a metal component of the iron group are contained in the central part of the catalyst and its vicinity, and a metal component of Group VIb of the periodic table is contained in the outer surface part of the catalyst and its vicinity. In this case, the metal raw material of the iron group of the periodic table is contained only in the carrier raw material in the central part of the catalyst and its vicinity, and the obtained first kneaded product is the second kneaded material containing no metal component of the iron group. The periodic table VI b
The desired catalyst can be obtained by impregnating with a group metal component.

As a method of coating the surface of the first kneaded material with the second kneaded material, it is convenient to use the extrusion molding apparatus shown in FIG. That is, the first kneaded material is supplied into the inner cylinder 1 in FIG. 1, the second kneaded material is put between the outer cylinder 2 and the inner cylinder 1, and pressure is applied from above to extrude. If the inner diameters of the outlets of the inner cylinder and the outer cylinder are set to a and b, respectively, a kneaded material 1 having a diameter a is coated with a kneaded material 2 having a diameter b, so that a strand can be cut to an appropriate length. Due to
The catalyst formed into pellets can be obtained. Further, by making the horizontal cross-sectional shape of the apparatus outlet part 3 into a circle, four leaves, three leaves, etc., a catalyst having these cross-sectional shapes can be prepared. In this case, when three or more catalyst layers are formed, it may be manufactured using an apparatus having a plurality of inner cylinders. Further, as another coating method, a rolling granulator (Marmelizer) or the like or a combination thereof with a kneading method can be used.

That is, a method in which the composition powder corresponding to the above-mentioned first kneaded product is formed into a spherical shape by a rolling granulator and then coated with the composition powder corresponding to the second kneaded product, or , The first kneaded product was formed into a spherical shape by a rolling granulator, and then the second kneaded product
Is a method of coating the kneaded product or the composition powder corresponding thereto with a rolling granulator.

As the heavy oil treated using the catalyst of the present invention, atmospheric distillation residual oil, reduced pressure distillation residual oil, coal liquefied oil, shale oil, etc. which have been conventionally subjected to hydrotreatment can be used. However, the effect of the present invention becomes remarkable especially when a heavy oil containing 3 wt% or more of asphaltene content and 50 ppm or more in total of vanadium, nickel and the like is used as a raw material.

In addition, the reaction conditions of the hydrotreating are based on the type of raw heavy oil,
It is appropriately selected depending on the restrictions on the reactor, the desired product structure, the type of catalyst, etc., but is usually a temperature of 300 to 500 ° C., a pressure of 100 to 200 kg / cm ² , and a liquid hourly space velocity of 0.1 to 5 Hr ^−1. , Hydrogen to feedstock heavy oil supply ratio 400 to 3000 Nm ³ −H ₂ / kl − selected from the range of feedstock heavy oil.

[Examples] Example 1 Preparation of catalyst (Catalyst A) Alumina (Versa 1-250 manufactured by Kaiser) was placed in a double-arm kneader and kneaded for 30 minutes while adding water to obtain a kneaded product 1. The kneaded product was taken out from the kneader and stored so that the water content of the kneaded product did not evaporate.

Next, only water was added to silica gel (Mizukasil manufactured by Mizusawa Chemical Co., Ltd.) and the mixture was kneaded for 30 minutes with the same kneader to obtain a kneaded product 2.

Next, the above-mentioned kneaded material 1 is put inside the inner cylinder 1 of the apparatus shown in FIG. 1, and the kneaded material 2 is put between the inner cylinder 1 and the outer cylinder 2, and the kneaded material is extruded by pressing from above. The mixture was molded into pellets so that the volume ratio of the layer 1 to the layer of the kneaded material 2 was 1: 1. The formed pellets were dried at 120 ° C. for 12 hours and calcined at 550 ° C. for 1 hour using a ventilation kiln.

Then, the calcined pellets are impregnated with an aqueous solution of cobalt nitrate, dried and then impregnated with an aqueous solution of ammonium paramolybdate, and the carrier is supported so that the amount of cobalt metal is 2% by weight and the amount of molybdenum metal is 8% by weight.
After drying at 0 ℃ for 12 hours, use a ventilation kiln to
The catalyst A was prepared by calcining at 0 ° C. for 1 hour. Further, in order to estimate the pore structure of the catalyst A, the kneaded material 1 and the kneaded material 2 are separately molded in parallel with the production of the catalyst, dried and fired by the above method, and molybdenum is supported by the above method, It was dried and calcined to obtain catalysts A '(using the kneaded material 1) and A "(using the kneaded material 2).

The catalyst A contains the same metal components as the inner and outer layers, but the BET method has a pore structure in which the inner layer (A ') has a surface area of 230
m ² / g, pore volume 0.70 ml / g, pore diameter 50-150Å ratio is 7
The outer layer (A ″) has a surface area of 120 m ² / g and a pore volume of 0.
The proportion of 85 ml / g and the pore diameter of 150 to 600Å was 85%.

Hydroprocessing of heavy oil Catalyst A in a fixed bed reactor with an inner diameter of 25 mm and a length of 1000 mm
Was filled with 100 ml, and a heavy oil having the properties shown in Table 1 which is an atmospheric residual oil of Arabian heavy crude oil was hydrotreated under the conditions shown in Table 2.

Table 1 Specific gravity: 0.9896 Sulfur yellow: 4.27wt% Nitrogen: 0.27wt% Viscosity (50 ℃): 2000cst Vanadium: 90ppm Nickel: 30ppm Asphaltene: 6.5wt% Table 2 Pressure: 140kg / cm ² G LHSV: 0.30hr ^-1 Hydrogen / Oil: 700Nl / Reaction temperature: 405 ℃ Measure the amount of sulfur, vanadium and nickel in the product oil obtained as a result of hydrogenation treatment, and measure the desulfurization rate and demetalization rate (vanadium and nickel Calculated as the total amount).
The results are shown in FIGS. 2 and 3.

Example 2 Preparation of catalyst (Catalyst B) Alumina (Versa1-250, manufactured by Kaiser) was placed in a double-arm type kneader and kneaded for 2 hours while adding water. Next, an aqueous cobalt nitrate solution was added to this alumina so that the cobalt amount was 2.0% by weight, and the mixture was further kneaded for 15 minutes to obtain a kneaded material 1 '. The kneaded material 1'is supplied to the inner side of the inner cylinder 1 in FIG. 1, and the kneaded material 2 obtained in Example 1 is separately supplied between the inner cylinder 1 and the outer cylinder 2 to form the same as in the first embodiment. Then, it was dried and baked to obtain pellets. The fired pellets were impregnated with and supported with an ammonium paramolybdate aqueous solution so that the molybdenum metal content was 8% by weight with respect to alumina, dried at 120 ° C for 12 hours, and then at 550 ° C using a ventilation kiln. The catalyst B was prepared by firing for 1 hour. In parallel, catalysts B ′ and B ″ were obtained in the same manner as in Example 1.

Catalyst B is a double-layer catalyst in which the inner layer contains molybdenum and cobalt and the outer layer consists of molybdenum, and the pore structure according to the BET method is that the inner layer (B ') has a surface area of 230 m ² / g and a pore volume of 0.70 ml / g. , The proportion of pore diameter 50 to 150Å is 75%, the outer layer (B ″) has a surface area of 115 m ² / g, pore volume of 0.83 ml /
g, and the ratio of pore diameters of 150 to 600Å was 86%.

Hydrotreatment of Heavy Oil Using the catalyst B, the heavy oil was hydrotreated in the same manner as in Example 1, and the sulfur, vanadium, and nickel materials in the produced oil were measured to determine the desulfurization and demetalization rates. . The results are shown in FIGS. 2 and 3.

Comparative Example 1 Preparation of Comparative Catalyst C Alumina (Versa 1-250, manufactured by Kaiser) was placed in a double-arm type kneader and kneaded for 2 hours while adding water. This kneaded product was put into the inner cylinder 1 of FIG. 1 and between the inner cylinder 1 and the outer cylinder 2 in the same amount and molded in the same manner as in Example 1, dried and fired to obtain pellets. Cobalt and molybdenum were supported on this by the same method as for catalyst A, dried and calcined to obtain catalyst C. The catalyst C is a catalyst having the same pore structure and the same metal component in both the inner layer and the outer layer, and the BET method has a pore structure having a surface area of 230 m ² / g, a pore volume of 0.70 ml / g, and a pore diameter of 50.
The proportion of ~ 150Å was 75%.

Hydrotreatment of Heavy Oil Using the comparative catalyst C, the heavy oil was hydrotreated in the same manner as in Example 1, and the sulfur, vanadium and nickel materials in the produced oil were measured to determine the desulfurization and demetalization rates. It was The results are shown in FIGS. 2 and 3. As is clear from these results, the catalysts A and B of the present invention in which the pore diameter of the outer surface portion is large and the pore diameter of the central portion is small are longer than the catalyst C having the same small pore diameter in the inner and outer layers. It can be seen that high desulfurization and demetalization activities can be maintained over a period of time.
Further, the catalyst B in which molybdenum-cobalt is supported in the inner layer and only molybdenum is supported in the outer layer has almost no decrease in demetallizing activity, and has further excellent performance.

[Advantages of the Invention] The present invention increases the demetalization activity by increasing the pore size of the outer surface portion of the catalyst, and prevents poisoning due to metal adsorption to the catalyst central portion, thereby improving the metal removal rate. It can be maintained at a high level for a long period of time, and the life of desulfurization, denitrification, and decomposition activity can be significantly extended.

Further, in the present invention, the VI of the periodic table is added to the center of the catalyst.
By adding a group b metal component and an iron group metal component, and a group VIb metal component of the periodic table on the outer surface portion and its vicinity of the catalyst, the demetalization activity and the desulfurization activity can be further enhanced. it can.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an apparatus for producing the catalyst of the present invention. 1 …… Inner cylinder 2 …… Outer cylinder 3 …… Outlet a …… Inner cylinder outlet inner diameter b …… Outer cylinder outlet inner diameter Fig. 2 shows changes in desulfurization rate with time when heavy oil is hydrotreated, FIG. 3 shows the change over time in the demetalization rate (V + Ni) at that time.

Claims (5)

(57) [Claims] 1. A catalyst comprising a porous refractory inorganic carrier on which at least a metal component of Group VIb of the Periodic Table and / or a metal component of an iron group is supported, which is 1/5 to 2/3 of the total catalyst volume. The pore volume of the catalyst consisting of
The value measured by the T method is 0.5 to 0.8 ml / g, and the diameter is 50 to 150.
The Å pores have a pore size distribution of 50 to 90% of the total pore volume of 600 Å or less in diameter, and 1 / of the total catalyst volume.
The outer surface of the catalyst consisting of 5 to 2/3 and the pore volume in the vicinity thereof is 0.6 to 1.5 ml / g as measured by the BET method,
Pore with a diameter of 150 to 600Å is 5
A catalyst for hydrotreating heavy oil, which has a pore size distribution of 0 to 90%. 2. A metal component of the Group VIb metal group and a metal component of the iron group of at least the periodic table are supported on and in the vicinity of the center of the catalyst,
2. The catalyst according to claim 1, wherein a metal component of Group VIb of the periodic table is supported on the outer surface of the catalyst and in the vicinity thereof. 3. The catalyst according to claim 1, wherein the metal component of Group VIb of the periodic table is molybdenum. 4. The catalyst according to claim 1, wherein the iron group metal component is cobalt or nickel. 5. The catalyst according to any one of claims 1 to 4, wherein the catalyst supported on the central portion of the catalyst and its vicinity is alumina, and the catalyst supported on the outer surface portion of the catalyst and its vicinity is silica.