JPS5940503B2 - α-olefin duplication catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst for dimerization or co-dimerization of α-olefins.

More specifically, the present invention relates to a catalyst that is highly active in the dimerization or co-dimerization reaction of α-olefins and can be used for a long period of time without deteriorating its activity.
Dimers or codimers of α-olefins, typified by 4-methyl-1-pentene, are used as monomers for producing polyolefins.

Many basic catalysts have hitherto been proposed as catalysts for producing the corresponding dimers or codimers by dimerization or codimerization reactions of α-olefins.

However, most of these catalysts have drawbacks such as low activity, insufficient selectivity toward the desired product, or short catalyst life even if the initial activity is high, and they cannot be used on an industrial scale. There are few methods that can be effectively used in implementation. Among these basic catalysts that have been proposed in the past, catalysts in which sodium metal is dispersed in granular anhydrous potassium compounds are disclosed in Japanese Patent Publication No. 42-22474, Japanese Patent Publication No. 43-25344, and Japanese Unexamined Patent Application Publication No. 1987-55. It is disclosed in Japanese Patent Laid-Open No. 145533-14553 and Japanese Patent Application Laid-open No. 145534-1983. In particular, among these proposals, the
Publication No. 474 shows an example in which granular potassium carbonate containing a small amount of graphite is used as a granular anhydrous potassium compound as a carrier, but all of these catalysts have poor catalytic activity and selectivity to the desired product. It is also advantageous in terms of ease of preparation and handling during industrialization, but since the catalyst activity decreases in a relatively short period of time, the catalyst must be replaced frequently. Furthermore, among the basic catalysts that have been proposed in the past, catalysts in which alkali metals are supported on various types of carriers other than the above-mentioned anhydrous potassium compound have been proposed.
For example, attempts have been made to use a catalyst in which an alkali metal is supported on a carbon carrier such as graphite as a dimerization catalyst for α-olefin.
, No. 822, No. 912,823, and No. 932,342, these catalysts also have sufficient catalytic activity, catalyst life, and selectivity to the target dimerization product as described above. are not expensive, and none of them are used on an industrial scale. Therefore, in any case, it is a challenge to improve the catalytic activity and extend the active life of a catalyst in which an alkali metal is supported on a carrier. Similarly, in the method using catalytic converters, the biggest challenge is to improve the catalytic activity and to suppress the decrease in the activity. The present invention was made in view of the above-mentioned current situation, and its object is to provide a catalyst for dimerization or co-dimerization of α-olefins that is highly active, highly selective to the target product, and has a long life. Our goal is to provide the following.

The present invention is based on the discovery that the above object can be achieved by using a catalyst in which an alkali metal mixture of a specific composition is supported on a compression-molded granular carrier containing anhydrous potassium carbonate having specific properties as a main component. It is. To summarize the present invention, the present invention provides a catalyst in which an alkali metal prisoner is supported on a carrier (B) mainly composed of anhydrous potassium carbonate, in which (1) the alkali metal (A) is sodium metal (a) and consisting of a mixture of potassium metal (b) whose composition is from 20 to 90% of sodium metal (a)
(4) the carrier [B
], the average particle size of the raw powder before compression molding is 150 to 60
Anhydrous potassium carbonate (anhydrous potassium carbonate ( c) is a compression-molded granular carrier consisting of (111), and the pore volume ratio of the carrier [B] is
in the range of 22 to 38%, and the compressive strength is 1.5
The present invention is a catalyst for dimerizing α-olefin, which is in the range of from 151<g/0f1i-G.

The alkali metal prison, which is one of the constituent components of the catalyst of the present invention, consists of a mixture of sodium metal (a) and potassium metal (b), and its composition is 20% of sodium metal (a).
and potassium metal (b) in the range from 90 g at %
It should be in the range of 10 to 80 gram at%.

The composition ratio of sodium metal among the alkali metals is 90
When the composition ratio of potassium metal becomes larger than 10 g atom % and the composition ratio of potassium metal becomes less than 10 g atom %, the catalyst activity and selectivity to dimerization products decrease, and when the composition ratio of sodium metal becomes 20 g atom % % and when the composition ratio of potassium metal exceeds 80 g at %, the initial activity of the catalyst becomes high, but the activity decreases significantly and the catalyst life becomes short. Furthermore, the composition of the alkali metal mixture is 30 to 85 sodium metal (a).
A range of 15 to 70 gram at % of potassium metal (b) is preferred because it provides a catalyst with excellent catalytic activity, catalyst life, and selectivity to the desired dimerization product. This alkali metal mixture contains
If necessary, other components may be blended to form a supporting component. Further, the carrier (B')-. of the alkali metal mixture in the carrier component. The supported proportion of is generally in the range of 0.5 to 10% by weight, preferably 1 to 5% by weight, based on the anhydrous potassium compound (c) as a component of carrier [B].

The carrier (B), which is another component of the catalyst of the present invention, is a compression-molded granular carrier containing anhydrous potassium carbonate as a main component,
More specifically, it is a compression-molded granular carrier prepared from raw powder of anhydrous potassium carbonate having specific properties. The raw powder of the anhydrous potassium carbonate constituting the compression molded granular carrier (B) before compression molding has an average particle size of 150 to 600 μm.
Anhydrous potassium carbonate having a particle size distribution in which the powder with a particle size of less than 100μ is in the range of 1 to 15% by weight, and the powder with a particle size of more than 600μ is in the range of 1 to 20% by weight. It is necessary. Furthermore, the average particle size is in the range of 200 to 600μ, and the particle size is 100μ.
Compression molded granules obtained from raw powder of anhydrous potassium carbonate having a particle size distribution in which the powder with a particle size of less than 600 μm is in the range of 2 to 10% by weight and the powder with a particle size of more than 600 μm is in the range of 2 to 15% by weight. The catalyst prepared from the support has catalytic activity,
This is preferred because catalyst life and selectivity to dimerization products are improved. Anhydrous potassium carbonate raw powder with a narrow particle size distribution, such as ordinary commercially available anhydrous potassium carbonate powder with an average particle size in the range of 350 to 800μ, has a composition of powder with a particle size of less than 100μ and a powder with a particle size of more than 600μ. The catalyst prepared from the compression-molded carrier obtained from this anhydrous potassium carbonate raw powder has a catalytic activity,
Catalyst life and selectivity to dimerization products become reduced. The bulk density of the anhydrous potassium carbonate constituting the compression molded granular carrier (B) before compression molding is usually 1.09/W.
Ll or less, and the bulk density is 0.9 to 0.59/ml
It is preferable to use the anhydrous potassium carbonate in the range of 1 to 1 as a component of the compression-molded granular support because it improves catalyst activity, catalyst life, and selectivity to dimerization products. Note that the anhydrous potassium carbonate having the specific properties used in the method of the present invention can be prepared by various methods.

For example, a conventionally known method involves blending anhydrous potassium carbonate powder with a narrow particle size distribution with anhydrous potassium carbonate powder with a different distribution to achieve the above-mentioned particle size distribution. It can be prepared by The carrier, which is a component of the catalyst of the present invention, is mainly composed of anhydrous potassium carbonate as mentioned above.
Small amounts of other ingredients may be added as needed. Further, the carrier constituting the catalyst of the present invention (Bl is a compression-molded granular carrier containing the above-mentioned anhydrous potassium carbonate (c) as a main component and having specific properties; more specifically,
The compression-molded granular carrier (B) needs to have a pore volume ratio in the range of 22 to 38% and a compressive strength in the range of 1.5 to 151<9/CTii-G.

There is a correlation between this pore volume ratio and compressive strength.
Outside the above numerical range, when the pore volume ratio of the compression-molded granular carrier [B] increases and the compressive strength decreases,
The initial activity of the catalyst is high to some extent, but the activity is likely to decrease and the catalyst life will also be shortened.Also, since the strength of the prepared catalyst is insufficient, it will crumble and turn into powder during use, which will shorten the catalyst life. further decreases, making it unusable on an industrial scale. In addition, the compression molded carrier (
When the pore volume ratio of B] becomes smaller and the compressive strength becomes larger, the catalyst activity becomes lower and the selectivity to the desired dimerization product decreases. In order to obtain a catalyst with excellent catalytic activity, catalyst life, and selectivity to dimerization products, and which is suitable for use in industrial-scale reactions, the compression-molded granular support [B] must have a pore volume ratio of is in the range of 26 to 33%, and its compressive strength is in the range of 2 to 10
It is preferably in the range of k9/Crd-G. As mentioned above, the essential supporting component constituting the catalyst of the present invention is an alkali metal mixture consisting of sodium metal (a) and potassium metal (b), but if its composition falls within the scope of the present invention, In addition to the above-mentioned essential alkali metal mixture, other components may be added to the supporting component as a mixture, if necessary. Here, when the supporting component consists only of the alkali metal mixture, it is a liquid or solid material consisting of a sodium-potassium alloy, but when the supporting component is a mixture of the alkali metal mixture and the other components, it is a paste. It is in a state of

The catalyst of the present invention can be prepared by various methods.

First, the compression-molded granular carrier (B) constituting the catalyst of the present invention
can usually be prepared by the following method. A powder composition containing anhydrous potassium carbonate (c) having the above-mentioned specific properties as a main component is compression molded using a tablet molding machine, a compression molding machine, a pelletizer, or the like. At that time, the compression molded granular carrier (B) is obtained by molding so that the pore volume ratio and compressive strength after molding are within the above range.The shape of this compression molded granular carrier may be any shape. However, it is usually formed into a tablet, pellet, or spherical shape, and the particle size thereof is usually 0.5 mm or more, preferably in the range of 1 to 10 mm.The catalyst of the present invention can be used in the above method. The compression-molded granular carrier thus prepared [B
) is prepared by supporting the above-mentioned supporting components. Various methods can be employed to support the compression-molded granular carrier (B) with the supporting component.
In either case, when sodium metal (a) is used as the alkali metal of the supporting component, the alkali metal undergoes an exchange reaction by contacting the sodium metal (a) with anhydrous potassium carbonate (c) under heating. to produce potassium metal and anhydrous sodium carbonate. Therefore, the composition of the alkali metal (A) consisting of sodium metal (a) and potassium metal (b) in the supported component of the prepared catalyst is changed to It is necessary to adjust it so that it falls within the range. Therefore, as the alkali metal component before being supported, sodium metal can be used alone, or an alloy of sodium metal and potassium metal can be used. Specifically, the following method can be exemplified as the supporting method. [1] A method in which sodium metal and the compression-molded granular carrier (Bl) are brought into contact with each other under heating and stirring in an inert gas atmosphere.

(2) A method in which a mixture of sodium metal and optionally other supported components is brought into contact with the compression-molded granular fingers (B) under heating and stirring in an inert gas atmosphere.

[3] An alloy of sodium metal and potassium metal and the compression-molded granular carrier (B) in an inert gas atmosphere,
Method of contacting under heating and stirring.

(4) A method in which a mixture consisting of an alloy of sodium metal and potassium metal and other supported components as necessary is brought into contact with the compression-molded granular carrier (B) under heating and stirring in an inert gas atmosphere. Here, the temperature during the supporting treatment is usually in the range of 150 to 400°C, but in order to obtain a catalyst with excellent catalytic activity, catalyst life, and selectivity to dimerization products, it is necessary to set the temperature at 200 to 350°C. It is preferable to carry out the supporting treatment at a temperature within a range.

Conventionally known α-olefin dimerization catalysts have been commonly used in areas where the conversion rate of α-olefin is high, but their drawbacks are that the activity of the catalyst is significantly reduced, and it is difficult to reduce the conversion rate of α-olefin. However, even if the catalyst was used, it was not possible to significantly reduce the activity of the catalyst and improve the selectivity to dimerized products.

In contrast, compared to any conventionally known catalyst, the catalyst of the present invention not only suppresses the decrease in activity even in the region where the conversion rate of α-olefin is high, but also is low, especially when the rate of change of α-olefin is 5.
In the range of 0% or less, the decrease in catalyst activity is significantly suppressed, the catalyst life is long, and the selectivity to dimerization products is high. The catalyst of the present invention is used in the dimerization reaction or co-dimerization reaction of α-olefin.

Specific examples of α-olefins include lower α-olefins such as ethylene, propylene, 1-butene, isobutylene, and 1-benzene. Among these dimerization reactions or co-dimerization reactions, production of 4-methyl-1-benzene by dimerization of propylene, production of 3-methyl-1-benzene by co-dimerization of 11-butene and ethylene,
Preference is given to using the catalyst of the invention for the production of 2-methyl-1-benzene by co-dimerization of isobutylene and ethylene, in particular for the production of 4-methyl-1-benzene by co-dimerization of propylene.
Preference is given to using the catalyst of the invention for the production of 1-benzene. The dimerization reaction or co-dimerization reaction of α-olefin using the catalyst of the present invention is carried out by a gas phase method or a liquid phase method under heating, but it is preferably carried out by a gas phase method.

The temperature when carrying out the reaction by the gas phase method is usually 0 to 300°C.
℃, preferably 100 to 200℃. The pressure during the reaction is usually normal pressure to 200k9/CTli-G1
Preferably it is in the range of 20 to 150 K9/dG. Although the reaction can be carried out in a fixed bed system or a fluidized bed system, it is preferable to carry out the reaction in a fixed bed system. When the reaction is carried out in a fixed bed method, the liquid hourly space velocity (LHSV) of α-olefin is usually 0.1 to 10 hr.
-1 is preferably in the range of 0.5 to 5 hr-1.
After the reaction is completed, unreacted α-olefin and products are separated from the mixture according to a conventional method, and the unreacted α-olefin is recycled and reused in the reaction. EXAMPLES Next, the method of the present invention will be specifically explained using Examples, but the present invention is not limited thereto. The physical properties of the carrier and supported catalyst shown in the Examples were measured as follows.

(1) Measurement of particle size distribution of raw powder of anhydrous potassium carbonate Combine JIS standard standard sieves from 16 mesh to 200 mesh, put a sample of raw powder of anhydrous potassium carbonate of about 1509 on top of the sieves, and place the whole into a polyethylene sieve. Put it in a bag and seal it.

This sieve was set in a low-tap vibratory sieve shaker (Kurihara Seisakusho 19-45) and sieved for 10 minutes under the conditions of shaking 290 times/min and hammering 156 times/min. The weight of the anhydrous potassium carbonate on each sieve after sieving was measured, the weight percentage was calculated, and the average particle size was determined from the RRS diagram. (2) Measurement of pore volume ratio of carrier Using approximately 109 carrier samples that had been heated and dried at 300°C for 2 hours, the specific gravity of the carrier was measured in mercury and carbon tetrachloride at 40°C. The ratio of the pore volume to the volume of the pore volume was determined as a volume percentage using the following formula as the pore volume ratio.

νν14●νν14 Here, DHy and DCOl4 are
ρH9 and ρ represent the specific gravity of the carrier measured in mercury and carbon tetrachloride, respectively.

. 14 represents the density of mercury and carbon tetrachloride at 40°C, respectively.

(3) Measurement of graphite content in the carrier 100ml of water and 20a of methanol were added to the carrier sample of 509, which had been heated and dried at 300°C for 2 hours.
After stirring with a magnetic stirrer for 0 minutes, the mixture was further stirred with an ultrasonic cleaner for 30 minutes.

After washing the liberated graphite with water, it was dried at 100°C for 2 hours, the weight was measured, and the weight was expressed as a percentage by weight relative to the anhydrous potassium compound in the carrier. (4) Measurement of supported alkali metal component composition About 2 g of the supported catalyst was accurately weighed, and 15 TI of water was added in a nitrogen atmosphere.
11 was added, and the amount of hydrogen gas generated was measured using a gas bottle.

The temperature at the time of measurement is TCC), the pressure is P (M77!Hg),
The partial pressure of water in TCC) is PHO (MmHg), the amount of gas generated is V (ml), the amount of alkali metal supported in the measured supported catalyst M (9) is A (g), and the carbon content is C (g).
), and the amount of alkali metal supported on anhydrous potassium carbonate 1009 is B (9 atoms), and the values of A and B were determined from the following formula. On the other hand, 50 m4 of anhydrous isopropyl alcohol was added to the supported catalyst 29 in a nitrogen atmosphere, and after being left at room temperature for 1 hour, the carrier and other solids were centrifuged.

The amounts of sodium alkoxide and potassium alkoxide eluted into the isopropyl alcohol thus obtained were measured by atomic absorption spectrometry, and the Na/K ratio was determined from both values. In addition, the amount of Na and the amount of K with respect to anhydrous potassium carbonate 1009 in the supported alkali metal component constituting the supported catalyst are as follows:
It was determined by the following formula from the supported alkali metal amount B (9 atoms) and the Na/K ratio for 009.

Na content (9 atoms/1009 anhydrous K compound) K content (9 atoms/1009 anhydrous K2CO3) ]) Measuring the bulk density of raw powder of anhydrous potassium carbonate It has a sample drop opening at the lower end and its inner diameter is 26.5 m1 ! , the inner diameter of the upper end is 941tm1 and the height is 100m77! The funnel, which had an internal volume of 150 m1, was fixed vertically so that the height from the bottom end of the funnel to the sample droplet was 10,011 mm.

Directly below the sample droplet of this funnel, there is an inner diameter of 39 mm and a height of 81 mm.
A cylindrical receiver with mT1 and internal volume of 98.0TLI was placed. Anhydrous potassium carbonate sample powder was placed in the funnel, a sample drop opening at the bottom was opened, and the sample powder was dropped into the receiver. The raised sample at the top of the receiver was ground horizontally. The weight of the sample in the receiver was measured and the bulk density was determined. Other physical properties were measured by conventional methods.

Example 1 (1) Preparation of catalyst A particle size distribution was prepared in which the average particle size was 300μ, 4.8% was less than 100μ, and 4.2% was more than 600μ and up to 1000μ. The bulk density is 0.7g.
/ml of anhydrous potassium carbonate and contains 0.5% by weight of graphite based on the anhydrous potassium carbonate with a diameter of 3 m7J! A cylindrical carrier with a height of 3 mm was molded into tablets.

After drying this carrier 97.59 at 350°C in a nitrogen stream for 2 hours, 2.59% sodium was added in a nitrogen atmosphere, and the mixture was stirred at 230°C for 5 hours to prepare a catalyst.

The physical properties of the carrier and supported catalyst are shown in Table 1 below together with the results of each example. (2) Dimerization reaction A propylene dimerization reaction was carried out using the catalyst prepared in (1) above.

A pressure-resistant gas phase reactor was filled with catalyst, and propylene was heated at a liquid hourly space velocity (LHS) of 0.85 hr while maintaining the reactor pressure at 100 kg/C7lt-G and temperature at 157°C.
-1, and continuous reaction was carried out. As a result, the propylene conversion rate reached a maximum of 82% after 5 hours, and then gradually decreased. The half-life of maximum activity, ie, the time required for the maximum conversion of propylene to be halved, was 1800 hours. In addition, 4-methyl- in the hexene fraction of the product
The content of 1-benzene was 92%. Example 2 The same procedure as in (2) of Example 1 was carried out, except that the catalyst prepared in (1) of Example 1 was used and the dimerization reaction of propylene was carried out under the conditions of LHSV 2.7 hrl and 150°C. I went.

The results are shown in Table 1. Examples 3 to 4 The samples shown in Table 1 were prepared by using anhydrous potassium carbonate having the same particle size distribution and bulk density as those used in Example 1 (1), and changing the pore volume ratio and compressive strength. The carrier was compressed into tablets.

Using this carrier, the catalysts shown in Table 1 were obtained by preparing according to the method (1) of Example 1. Using this catalyst, a propylene dimerization reaction was carried out under the same conditions as in Example 2. The results are shown in Table 1. Comparative Example 1 In (1) of Example 1, the sodium loading conditions were changed to 14
The catalysts shown in Table 1 were prepared by changing the temperature to 0° C. for 2 hours.

Using this catalyst, a propylene dimerization reaction was carried out under the same conditions as in Example 2. The results are shown in Table 1. Comparative example 2
~3 A carrier was prepared in the same manner as in (1) of Example 1, using anhydrous potassium carbonate having the same particle size distribution and bulk density as those used in (1) of Example 1, but changing the pore volume ratio and compressive strength. was compressed into tablets.

Using this carrier, the catalysts shown in Table 1 were obtained by preparing according to the method (1) of Example 1. Using this catalyst, a propylene dimerization reaction was carried out under the same conditions as in Example 2. The results are shown in Table 1. Comparative Example 4 It has a particle size distribution with an average particle size of 450μ, 0.5% for particles with a particle size of less than 100μ, and 27.6% for particles with a particle size of more than 600μ and up to 1000μ, and a bulk density of 1. .1
9/ml of anhydrous potassium carbonate containing 0.5% by weight of graphite according to the same method as in Example 1 (1). The cylindrical carrier was compressed into tablets.

Using this carrier, the catalysts shown in Table 1 were obtained by preparing according to the method (1) of Example 1. Using this catalyst, a propylene dimerization reaction was carried out under the same conditions as in Example 2. The results are shown in Table 1. As is clear from Table 1 above, the catalyst of the present invention has particularly remarkable effects on catalyst activity, catalyst life, and selectivity to dimerization products compared to the catalyst of the comparative example.

Claims (1)

[Scope of Claims] 1. A catalyst in which an alkali metal [A] is supported on a carrier [B] whose main component is anhydrous potassium carbonate, in which (i) the alkali metal [A] is supported by sodium metal (a) and potassium (ii) the carrier [B ], the average particle size of the raw powder before compression molding is in the range of 150 to 600μ, and the powder with a particle size of less than 100μ is in the range of 1 to 15% by weight, and the powder with a particle size of over 600μ is in the range of 1 to 15% by weight. It is a compression-molded granular carrier consisting of anhydrous potassium carbonate (c) having a particle size distribution in the range of 20 to 20% by weight, and (iii) the pore volume ratio of the carrier [B] is in the range of 22 to 38%. and has a compressive strength of 1.5 to 15 kg/cm^2
A catalyst for dimerizing α-olefins, which is in the range of −G. 2 The carrier [B] has an average particle size of raw powder before compression molding of 2
00 to 600μ, and the powder with a particle size of less than 100μ is in the range of 2 to 10% by weight, and the particle size is 60μ
A catalyst according to claim 1, which is a compression-molded granular carrier consisting of anhydrous potassium carbonate (c) with a particle size distribution in the range of 2 to 15% by weight of powder larger than 0μ. 3 The pore volume ratio of the carrier [B] is in the range of 26 to 33%, and the compressive strength is 2 to 10 kg/cm^2
3. The catalyst according to claim 1 or 2, which is a compression molded granular carrier in the range -G. 4 The composition of the alkali metal [A] is sodium metal (
A catalyst according to any one of claims 1 to 3 in which a) is in the range from 30 to 85 gram at % and potassium metal (b) is in the range from 15 to 70 gram at %.