JPH0763626B2 - Wax isomerization catalyst and wax isomerization method - Google Patents

Description

Detailed Description of the Invention

FIELD OF THE INVENTION The present invention relates to a catalyst and a wax using the catalyst, which is suitable for isomerizing a wax, particularly hydroisomerizing a slack wax to produce a lubricating base oil having a high viscosity index. It relates to an isomerization method.

[0002]

2. Description of the Related Art Conventionally, various methods have been proposed for isomerizing slack wax and producing a lubricating base oil having a high viscosity index by selective hydrocracking. The isomerization of the wax among them progresses even with a general hydrorefining catalyst using alumina as a carrier, but it is difficult to obtain a practically sufficient isomerization rate. Therefore, a method of adding fluorine to the catalyst for the purpose of improving the acidity of the catalyst or adding a nitrogen compound to the raw material for improving the isomerization selectivity (Japanese Patent Publication No. 57-17037 and Japanese Patent Publication No. 59-184).
No. 38) is known.

Further, a method of reacting under a dewaxing condition using a catalyst carrying zeolite and a hydrogenated / dehydrogenated metal component (JP-A-62-112691, JP-A 1-2)
No. 59087) has also been proposed.

Since the dewaxing catalyst containing this zeolite has too strong an acidity, it is suitable for obtaining a lubricating base oil having a low pour point because of its conversion to a light fraction, that is, high cracking activity and low isomerization activity. However, it is difficult to obtain a lubricating base oil having a sufficiently high viscosity index for practical use in good yield.

On the other hand, although a catalyst containing fluorine is effective for isomerization, the catalyst preparation process becomes complicated and it may not reach a sufficient isomerization activity. Therefore, there has been a strong demand for the development of a wax isomerization catalyst which can be prepared by a simple method and has a low decomposition activity and a high isomerization activity.

[0006]

DISCLOSURE OF THE INVENTION The present invention is to solve the above problems, and an object of the present invention is to provide a wax isomerization catalyst having a low decomposition activity and a high isomerization activity, and a high viscosity index using the catalyst. It is intended to provide a wax isomerization method for obtaining a lubricating base oil having a high yield in a high yield.

[0007]

When wax is isomerized using a catalyst in which a metal hydride component is supported on a refractory oxide carrier, linear paraffin components in the wax are dehydrogenated on the metal component. It is believed that the skeletal isomerization is then carried out at the acid sites on the refractory oxide support and again hydrogenated on the metal to be converted into branched paraffins. Therefore, in order to promote isomerization rapidly, both the functions of dehydrogenation and hydrogenation of metal and the skeleton isomerization function of acid sites must be enhanced in a well-balanced manner.

In this case, strong acidity is required for isomerization, but the acidity must be adjusted appropriately in order to suppress competing decomposition reactions. When silica / alumina or zeolite is used as the refractory oxide carrier, the decomposition reaction is prioritized because the acidity is too strong, and thus only a low yield and a low viscosity index product oil are often obtained. However, it is considered that the addition of a small amount of silica to alumina has a suitable influence on the acidity, and that the acidity suitable for the isomerization of wax can be obtained. Therefore, as a result of extensive studies on silica to be added to alumina, it was found that the use of silica gel as the silica source can reduce the decomposition rate to light components and improve the isomerization rate of linear paraffins to branched paraffins. I found it.

The present invention has been made on the basis of such findings, and the present invention is that alumina is mixed with silica gel and kneaded,
One of molybdenum and nickel or cobalt is added to the refractory oxide carrier obtained by drying and firing the kneaded product.
One or both , and preferably, further loaded with phosphorus
A wax isomerization catalyst comprising the above, and a wax isomerization method comprising contacting the wax with the catalyst under hydrogen pressure.

Alumina hydrate is included in the alumina used in the present invention, and any alumina that is usually used for the preparation of catalysts or any alumina hydrate can be used without any particular problems. Can be used without.

Although silica gel which is generally commercially available can be used, it has a surface area of 500 m ² / g or more and a pore volume of 0.7 ml / g or more and a median of 100 μm or less, particularly preferably 1 to 50 μm. Those having a particle size can be used. This silica gel has 1 to 1
It is preferable to mix in the range of 30% by weight. If the amount of silica gel mixed is 1% by weight or less, the isomerization activity will be small, and if it is 30% by weight or more, the decomposition activity will be high and the yield of lubricating oil having a high viscosity index will be reduced, such being undesirable.

On the other hand, the supported metal has a hydrogenating ability.
However, it is not affected by the poisoning effect of sulfur,
Nitrogen is added to molybdenum to increase its hydrogenation activity.
It is preferable to use either one or both of Kell and cobalt . In addition to these metal components, if other elements such as phosphorus are supported, it becomes even easier.
It is preferable because the activity can be improved . The amount of these supported metals is a total amount as a metal component with respect to the catalyst, preferably 3 to 30% by weight, and particularly preferably 10 to 20% by weight. 1 to 7% by weight of other elements such as phosphorus
It is recommended to properly select within the range.

The wax applicable to the present invention is not particularly limited in its kind, but it is a slack wax obtained in the dewaxing step which is one of the steps for producing a lubricating oil, that is, a reduced-pressure medium, a heavy fraction or a reduced pressure. The slack wax obtained by subjecting the residual deasphalted oil to a furfural solvent extraction treatment and then to a hydrorefining device or to a solvent dewaxing device without treatment is preferred. These waxes may be treated individually for each fraction, or may be used as a mixture with those of other fractions.

The catalyst of the present invention can be prepared as follows.

First, alumina and silica gel are mixed and kneaded, but both may be mixed before kneading, or silica gel may be added and mixed while kneading alumina and kneading. There is no need to do anything special for this mixing, just mechanical mixing. In this kneading, a 1-5% nitric acid solution can be used as a peptizer, and any known kneader can be used. After kneading, it may be molded using an extruder or the like. In this case, the shape is preferably cylindrical, three-lobed, spherical, etc. in consideration of the isomerization reactor to be used.
It is advisable to have a maximum cross-sectional diameter of 16 to 1/32 inch.

Next, this molded product is dried at a temperature of 50 to 200 ° C. for 5 to 24 hours and calcined in the air at a temperature of 250 to 800 ° C., preferably 400 to 700 ° C. for 1 to 2 hours. To do. The refractory oxide carrier thus obtained is loaded with the above-mentioned metal components by an impregnation method or the like,
Dry at a temperature of ~ 200 ° C for 5-24 hours, 250-7
At a temperature of 00 ° C, preferably 400-600 ° C,
Bake in air for 0.5 to 2 hours.

The isomerization reaction can be carried out in any of a fixed bed, a moving bed and a fluidized bed, a temperature of 320 to 420 ° C., a hydrogen pressure of 50 to 150 kg / cm ^{2, and} a pressure of 500 to 1500 l.
/ L ratio of hydrogen / oil, liquid hourly space velocity of 0.5-1.0 hr ^-1 (L
It is preferable to carry out under HSV) reaction conditions.

In order to obtain a high viscosity index and a high yield,
It is preferable to set the reaction conditions such that the conversion rate of the linear paraffin is 80% by weight or more and the conversion rate of the raw slack wax into the light fraction having a boiling point of the initial boiling point or less is 40% by weight or less. . Linear paraffin conversion of 80
If it does not reach the weight percentage, a high viscosity index can be expected,
In the dewaxing process, the oil yield is low, and a sufficiently low pour point may not be achieved. Further, if the conversion to light components exceeds 40% by weight, only a low yield can be obtained and a high viscosity index cannot be maintained, which is not preferable.

The product oil obtained by this isomerization reaction contains a light fraction which is not desirable as a lubricating base oil.
This is separated by distillation or the like. It is preferable to carry out this distillation under reduced pressure, to remove a fraction having a boiling point of 350 ° C. or lower,
It is advisable to obtain a residue having an initial boiling point of 330 to 370 ° C.

After distilling the isomerized product, it can be made into a lubricating base oil by subjecting it to a dewaxing apparatus. Dewaxing in this case may be solvent dewaxing which is generally carried out, for example, using a mixed solvent of methyl ethyl ketone / toluene (1/1 volume ratio), in a solvent / oil ratio of 2/1 to 4/1, It is advisable to carry out at a temperature of 20 to -30 ° C.

[0021]

【Example】

(Examples 1 and 2) 1547 g of alumina was put into a kneader,
Add 1 liter of 3% nitric acid aqueous solution as a peptizer, and add 3
Knead for 0 minutes and add silica gel A (surface area 514 m ² /
g, pore volume 0.85 ml / g, median diameter 75 μm) 81.4
g was added and kneading was continued for 30 minutes. This kneaded product is 1.
It was molded into a columnar shape by an extruder having a die having a hole of 6 mmφ and dried at 130 ° C. overnight. The dried product was calcined in a rotary kiln at 600 ° C. for 1 hour to obtain a catalyst carrier. This carrier has a specific surface area of 272 m ² / g and a pore volume of 0.69 m
l / g, central pore size 86 Å, SiO ₂ 5.4 wt%
Included.

150 g of the above carrier was impregnated with an impregnation solution containing 45.8 g of ammonium molybdate, 41.1 g of nickel nitrate hexahydrate and 15.4 g of phosphoric acid solution. This was dried at 130 ° C. overnight and then calcined at 500 ° C. for 30 minutes to obtain a catalyst A.

A catalyst B was prepared by the same method except that the amount of silica gel added was 116.4 g. Table 1 shows the composition, specific surface area, pore volume, and median pore diameter of these catalysts A and B.

After the catalysts A and B obtained above were sulphurized using a fixed bed flow type experimental apparatus, a reduced pressure heavy slack wax having the properties shown in Table 2 was used, and an isomerization activity test was conducted under the conditions shown in Table 1. Was done. The results are shown in Table 1. In addition, the reduction rate of linear paraffin was expressed as a paraffin conversion rate, the production rate of a fraction having a boiling point lower than 330 ° C. was expressed as a decomposition rate, and the difference between the paraffin conversion rate and the decomposition rate was expressed as an isomerization rate.

(Examples 3 to 5) 1547 g of alumina was placed in a kneader, 1 l of a 3% strength nitric acid aqueous solution was added as a peptizer, and the mixture was kneaded for 30 minutes. Silica gel B (surface area 517 m ² / g, fine Pore volume 0.79 ml / g, median diameter 25
μm) 116.4 g was added and kneading was continued for 30 minutes.
This kneaded product was molded into a columnar shape by an extrusion molding machine having a die having a hole of 1.0 mmφ and dried at 130 ° C. overnight. The dried product was calcined in a rotary kiln at 600 ° C. for 1 hour to obtain a catalyst carrier.

On this carrier 150g, molybdenum, nickel and phosphorus were loaded in the same manner as in the example to obtain catalyst C.

The composition of this catalyst C, the specific surface area, the pore volume,
The median pore size is shown in Table 1.

Using this catalyst C, using the same slack wax and apparatus as in Example 1, an isomerization activity test was conducted under the conditions shown in Table 1. The results are shown in Table 1.

[Table 1]

[Table 2]

(Comparative Examples 1 to 5) In Example 1, 81.4 g of commercially available silica alumina A (silica / alumina weight ratio: 87/13) and commercially available silica alumina B (silica / Alumina weight ratio is 30/70)
81.4 g, silica alumina B of 387 g, and USY zeolite of 81.4 g were used, and catalysts D, E, F, and G were prepared in the same manner as in Example 1. Further, the catalyst H was prepared in the same manner as in Example 1 without adding silica gel.

The composition, surface area, pore volume of these catalysts,
The median pore size is shown in Table 3.

After sulphurizing these catalysts in the same manner as in Example 1, an isomerization activity test was conducted under the conditions shown in Table 3 using the same experimental apparatus and slack wax as in Example 1.
The results are shown in Table 3.

[Table 3]

From the comparison between Tables 1 and 3, it can be seen that the catalyst of the present invention has excellent performance in wax isomerization. That is, in the catalysts D to H, the linear paraffin conversion rate is low and the isomerization ability is low, or even if the linear paraffin conversion rate is high, the yield of the fraction having a boiling point of 330 ° C. or less is high. While the drawbacks are many, that is, the decomposition rate is high and the yield of lubricating base oil is low, the catalyst of the present invention remarkably improves these drawbacks.

(Reference Example) The isomerized products obtained with the catalysts 1 and 5 were distilled under reduced pressure to remove light components, and the residual components were dewaxed to produce a lubricating base oil.

First, the obtained isomer was distilled under reduced pressure to remove light components, and a residue having an initial boiling point of 330 ° C. was obtained. Next, this residue was dewaxed under the conditions shown in Table 4.

The yield and properties of the resulting lubricating base oil are shown in Table 5.

[Table 4]

[Table 5]

As shown in Table 5, it can be seen that the catalyst of the present invention has excellent performance for producing a lubricating base oil having a high viscosity index.

[0037]

The wax isomerization catalyst of the present invention has a low decomposition rate and a high isomerization rate, and therefore has a particular effect that a lubricating base oil having a high viscosity index can be obtained in a high yield. It is a thing.

Claims (3)

[Claims] 1. A refractory oxide carrier obtained by mixing silica gel with alumina, kneading the mixture, and drying and firing the kneaded product, and molybdenum, nickel or cobalt.
A catalyst for wax isomerization, characterized in that one or both of them are supported. 2. A silica gel is mixed with alumina and kneaded.
Refractory oxide obtained by drying and firing the kneaded product
Either molybdenum and nickel or cobalt for the carrier
Characterized in that one or both of them and phosphorus are carried.
Wax isomerization catalyst. 3. A process according to claim 1 or pressurized hydrogen wax
A method for isomerizing a wax, which comprises bringing the catalyst for isomerizing a wax according to 2 into contact.