JPH08295640A - Production of 3-ethyl-1-olefin - Google Patents

Abstract

PURPOSE: To obtain the subject compound useful as a raw material for polyolefins by bringing a catalyst excellent in low-temperature activity and reaction selectivity into contact with propylene followed by codimerization when conducting codimerization between ethylene and an olefin. CONSTITUTION: This compound is obtained by bringing a catalyst prepared by carrying an alkali metal on a granular carrier composed of an anhydrous potassium compound and carbon (e.g. graphite) into contact with propylene at 130-170 deg.C under a pressure of 20kg/cm<2> G for 2-50h followed by codimerization between ethylene and a >=4C olefin (e.g. 1-butene) under a pressure of normal pressure to 100kg/cm<2> G at 70-120 deg.C in the presence of the above catalyst. The amounts of the alkali metal and the carbon to be used are 1-10wt.% and 0.2-3wt.% based on the whole amount of the catalyst. Propylene treatment of the catalyst prior to the codimerization markedly improves the catalyst activity, thus increasing the space time yield of this compound and enabling reaction at lower temperatures, and also resulting in longer catalyst life.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a process for producing 3-ethyl-1-olefin useful as a raw material for polyolefin. For details, use a catalyst with low temperature activity and excellent reaction selectivity.
It relates to a method for producing ethyl-1-olefin.

[0002]

2. Description of the Related Art Conventionally, it has been known that an alkali metal catalyst is effective for codimerization of ethylene and an olefin having 4 or more carbon atoms.

In J. Org. Chem., Vol.30, 3290 (1965), a Li-K catalyst is used to carry out a co-dimerization reaction of 1-butene, 2-butene, 1-pentene and the like with ethylene. , 3-methylpentene-1 (3-ethylbutene-1) and 3-ethylpentene-1 etc.
It is disclosed that 3-ethyl-1-olefins can be synthesized. However, due to the low activity of this catalyst,
It has the drawback of requiring high-temperature and high-pressure reaction conditions of 1 kg / cm ² G and very poor reaction selectivity.

Chem. Brit., Vol. 5, 354 (1969) also discloses a method for producing 3-methylpentene-1 from ethylene and 1-butene or 2-butene using an alkali metal catalyst. There is. The reaction conditions in this method are 85 ° C., 70 kg / cm ² G, and although relatively mild, the production rate of 3-methylpentene-1 is 20 to 22 g (3-methylpentene-1) / g. -It is very small with atomic alkali metal / hr.

[0005]

The object of the present invention is to provide a process for efficiently producing 3-ethyl-1-olefin in the co-dimerization of ethylene with an olefin having 4 or more carbon atoms by using a catalyst having a very high activity even at a low temperature. To provide.

[0006]

DISCLOSURE OF THE INVENTION The present invention is directed to the codimerization of ethylene and an olefin having 4 or more carbon atoms in the presence of a catalyst prepared by supporting an alkali metal on a granular carrier composed of an anhydrous potassium compound and carbon. In the method for producing 3-ethyl-1-olefin, the catalyst is brought into contact with propylene, and then co-dimerization is carried out.
It relates to a method for producing olefins.

In the present invention, potassium carbonate and potassium fluoride are preferable as the anhydrous potassium compound. Although each may be used alone, it is preferable to use a mixture of potassium carbonate and potassium fluoride because the co-dimerization reaction selectivity is increased.

As the anhydrous potassium compound, in addition to potassium carbonate and potassium fluoride, potassium halide such as potassium chloride, potassium bromide and potassium iodide, potassium sulfate, potassium nitrate, potassium silicate, potassium silicofluoride and the like are contained. Good.

Specific examples of the alkali metal used in the present invention include sodium, potassium and a mixture thereof. Generally, the reaction activity of sodium metal is considerably lower than that of potassium metal. However, when the sodium metal is brought into contact with potassium fluoride or potassium carbonate under heating, the sodium metal easily undergoes an exchange reaction to form sodium fluoride or sodium carbonate and potassium metal. It is also possible to use sodium metal alone as the metal component. In particular, in the present invention, the catalyst using sodium has a remarkable effect of improving the selectivity.

The amount of the alkali metal used is not particularly limited, but is preferably 1 to 10% by weight based on the total weight of the catalyst.
1.5 to 6% by weight is preferred. Generally, increasing the amount of the alkali metal supported increases the production rate per unit weight of the catalyst, which is industrially advantageous, but it is difficult to remove heat even if the amount is excessively increased, or the selectivity decreases. It is not preferable.

The carbon used in the present invention is activated carbon,
Examples include graphite and carbon black. These may be used alone or in a mixture of two or more. Particularly, graphite can be preferably used.

In the present invention, the amount of carbon used is not particularly limited, but is preferably 0.2 to 3.0% by weight based on the total weight of the catalyst.

In the present invention, carbon and an anhydrous potassium compound raw powder are sufficiently mixed, and the mixed raw powder is compressed into a tablet molding machine,
The granular carrier can be produced by compression molding with a compression molding machine, pelletizer or the like.

Anhydrous potassium compound is used as a mixed raw powder before compression molding and has a loose packing bulk density of 0.6 g / carbon-free state.
If it goes below ml, the flow will become poor and compression molding will not be possible. If it exceeds 1.2 g / ml, molding is easy,
The obtained granular carrier becomes dense with a small specific surface area. The potassium fluoride and potassium carbonate raw powders may be used as they are as they are, or they may be pulverized or granulated and then mixed. Alternatively, it may be pulverized after mixing.

The shape of the granular carrier is not particularly limited, but is usually cylindrical, pelletized, spherical, etc., and the particle size is usually 0.5 mm or more, preferably 1 to 10 mm. . The strength of the carrier is not particularly limited,
It may be in the range of 1.5 to 20 kg (radial crush strength).

The carrier must be dried before supporting the alkali metal. Dry under reduced pressure at 50-200 ℃ or 200-600 ℃
It is preferable to perform normal pressure firing. Only vacuum drying,
Only normal pressure firing or both may be performed.

The method of loading the alkali metal on the carrier is, for example, by stirring and mixing the dried or calcined carrier at a temperature above the melting point of the alkali metal, preferably at a temperature of 200 to 450 ° C. under an inert gas atmosphere. It can be carried out. The catalyst of the present invention does not show a significant decrease in crush strength even by the above-mentioned alkali metal supporting treatment, and can be effectively used as a practical catalyst.

In the present invention, the above catalyst is treated with propylene before the codimerization reaction. By this treatment, the co-dimerization activity of the catalyst is greatly improved as compared with the untreated one.
Since the space-time yield (STY) is increased and the reaction can be performed at a lower temperature, the reaction selectivity is improved and the catalyst life is extended.

The temperature of the contact treatment with propylene is preferably higher than that in the co-dimerization reaction, specifically 130 to 170 ° C.
More preferably 135 to 160 ° C., particularly preferably 140
It is in the range of ~ 155 ° C. If it is less than the above range, the improvement of the co-dimerization activity is not sufficient. If the amount exceeds the above range, the deactivation of the catalyst starts during the treatment, and similarly, a high co-dimerization activity cannot be obtained.

The propylene pressure at the time of contact is preferably 20 kg / cm ² G or more, more preferably 30 kg / cm ² G or more. Below the above pressure, the improvement of co-dimerization activity is not sufficient. The upper limit of the propylene pressure is not particularly limited, but is 150 kg / cm ² G from a practical viewpoint. The time required for the propylene treatment is not particularly limited as it is shortened as the contact temperature and pressure are higher, but it is practically in the range of 2 to 50 hours.

According to the method of the present invention, ethylene and an olefin having 4 or more carbon atoms are co-dimerized in the presence of the catalyst obtained as described above, preferably using a fixed bed method as a reaction method. To produce 3-ethyl-1-olefin.

Number of carbon atoms used in the co-dimerization method of the present invention
Specific examples of 4 or more olefins include 1-butene, 1-pentene, 1-hexene, 1-olefins such as 1-heptene, 2-
Examples thereof include 2-olefins such as butene, 2-pentene, 2-hexene, and 2-heptene. These olefins may be used as a mixture of two or more kinds such as 1-olefin and 2-olefin.

The co-dimerization method of the present invention is to produce 3-methylpentene-1 (3-ethylbutene-1) by co-dimerization of ethylene and 1-butene or ethylene and 2-butene. 3-Ethylpentene by Co-dimerization of Ethylene with 1-Pentene or Co-dimerization of Ethylene with 2-Pentene
It can be preferably used for the production of -1, production of 3-ethylhexene-1 by co-dimerization of ethylene and 1-hexene or co-dimerization of ethylene and 2-hexene.

In particular, the co-dimerization of 1-butene and ethylene,
Co-dimerization of ethylene with 2-butene or with 1-butene
It can be more suitably used for the production of 3-methylpentene-1 by co-dimerization of a mixture of 2-butene and ethylene.

The reaction pressure is in the range of atmospheric pressure to 100 kg / cm ² G. 2 kg because higher reaction pressure improves space-time yield
/ cm ² G or more is preferable. The upper limit of the reaction pressure is not particularly limited, but is 100 kg / cm from a practical viewpoint.
It is ² G.

The reaction temperature is preferably in the range of 70 to 120 ° C, more preferably 80 to 110 ° C. When the reaction temperature is lower than 70 ° C, the space-time yield becomes small. Also, 1
If it exceeds 20 ° C., the 3-ethyl-1-olefin selectivity is lowered, and the space-time yield (STY) becomes too large, which makes it difficult to remove heat from the reaction tube.

The liquid hourly space velocity (LHSV) of ethylene and an olefin having 4 or more carbon atoms is usually in the range of 0.5 to 10 hr ^-1 , preferably 1 to 7 hr ^-1 .

[0028]

INDUSTRIAL APPLICABILITY According to the present invention, in the co-dimerization of ethylene with an olefin having 4 or more carbon atoms, the catalyst is brought into contact with propylene and then the co-dimerization is carried out to obtain a high reaction selectivity with an increased low-temperature activity. There is provided a process for the production of 3-ethyl-1-olefins that can be obtained.

[0029]

Embodiments of the present invention will be described below.

Example 1 Average particle size 250 μm, bulk density 0.953 g / ml, specific surface area 0.84
m ² / g potassium carbonate powder and 0.99 wt% graphite powder were added and mixed well, and then tablet-molded into a cylindrical carrier having a diameter of 3 mm and a height of 3 mm. The crush strength (radial direction) measured using a Kiya type hardness tester was 4.7 kg. 2hr at 380 ℃
After the calcination, 2.49% by weight of metallic sodium was added in a nitrogen atmosphere, and the mixture was stirred at 370 ° C. for 4 hours to prepare a catalyst. This catalyst
63.53 g was packed in a tubular reactor with a catalyst volume of 54 ml and an inner diameter of 21 mm, and propylene was supplied at a liquid hourly space velocity (LHSV) of 4.6 hr ^-1 at a pressure of 100 kg / cm ² G and a temperature of 150 ° C for 22 hr of pretreatment. I went. After that, the temperature and pressure were reduced to 100 ° C and 5 kg / cm ² G, and ethylene was added at a molar ratio of ethylene / 1-butene of 0.67.
A mixed gas of 1-butene was supplied at LHSV of 4.2 hr ^-1 to carry out a continuous flow reaction. The conversion of ethylene after 1 hour is 17.6
%, The selectivity of 3-methylpentene-1 was 79.9%. The propylene pretreatment conditions, reaction conditions and reaction results are shown in Table 1, Table 2 and Table 3, respectively.

Example 2 50 parts by weight of potassium fluoride powder having an average particle diameter of 270 μm, a loosely packed bulk density of 1.148 g / ml and a BET specific surface area of 0.09 m ² / g,
Average particle size 250μm, bulk density 0.953g / ml, specific surface area 0.84
After mixing with 50 parts by weight of m ² / g potassium carbonate powder, the mixture was pulverized with a Willey pulverizer (500 μm screen). After adding 0.99% by weight of graphite powder to this pulverized raw powder and mixing them well, they were tablet-molded into a cylindrical carrier having a diameter of 3 mm and a height of 3 mm. The crushing strength (radial direction) measured using a Kiya hardness meter was 4.9 kg. After vacuum drying at 100 ° C for 20 hours,
2.50% by weight metallic sodium was added under a nitrogen atmosphere.
A catalyst was prepared by stirring at 70 ° C. for 4 hours. 66.38 g of this catalyst was filled in a tubular reactor with a catalyst volume of 54 ml and an inner diameter of 21 mm, and propylene was supplied at a liquid hourly space velocity (LHSV) of 4.5 hr ^-1 at a pressure of 100 kg / cm ² G and a temperature of 150 ° C for 13 hr. Pretreatment was performed. Then, lower the temperature and pressure to 100 ° C and 5 kg / cm ² G to 0.69
A mixed gas of ethylene and 1-butene at a molar ratio of ethylene / 1-butene was supplied at LHSV of 4.1 hr ^-1 to carry out continuous flow reaction. The propylene pretreatment conditions, reaction conditions and reaction results are shown in Table 1, Table 2 and Table 3, respectively.

Comparative Example 1 In the same manner as in Example 1, a cylindrical carrier having a diameter of 3 mm and a height of 3 mm was prepared. The crush strength was 8.2 kg. 2 at 380 ° C
After the hr calcination, 2.50 wt% of metallic sodium was added in a nitrogen atmosphere and stirred at 370 ° C. for 4 hr to prepare a catalyst. 64.34 g of this catalyst was charged into a tubular reactor and the pressure was 5 kg / cm ² G
, Temperature 100 ℃, ethylene / 1-butene molar ratio 0.60,
A mixed gas of ethylene and 1-butene was fed at LHSV of 4.1 hr ^-1 for continuous flow reaction. After 5 hours, the ethylene conversion rate was 4.4%. After 13 hours, the mixed gas supply conditions were changed to a pressure of 5 kg / cm ² G, a temperature of 110 ° C., an ethylene / 1-butene molar ratio of 0.61, and LHSV of 4.0 hr ⁻¹ to continue the reaction. After 18 hours (5 hours after changing supply conditions), the ethylene conversion rate was 7.9%. The propylene pretreatment conditions, reaction conditions and reaction results are shown in Table 1, Table 2 and Table 3, respectively.

Comparative Example 2 In the same manner as in Example 2, a cylindrical carrier having a crushing strength of 4.6 kg was prepared. After drying under reduced pressure at 100 ° C for 20 hours, under a nitrogen atmosphere,
The catalyst was prepared by adding 2.50 wt% of metallic sodium and stirring at 370 ° C. for 4 hours. 64.98 g of this catalyst was packed in a tubular reactor, pressure was 5 kg / cm ² G, temperature was 110 ° C., ethylene / 1-
A mixed gas of ethylene and 1-butene was supplied at a LHSV of 4.0 hr ^-1 at a butene molar ratio of 0.61, and a continuous flow reaction was carried out. The propylene pretreatment conditions, reaction conditions and reaction results are
The results are shown in Table 1, Table 2 and Table 3, respectively.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

Claims (1)

[Claims] 1. Ethyl and an olefin having 4 or more carbon atoms are co-dimerized in the presence of a catalyst prepared by supporting an alkali metal on a granular carrier composed of an anhydrous potassium compound and carbon, and 3-ethyl-1- A method for producing an olefin, which comprises contacting the catalyst with propylene and then performing co-dimerization, the method for producing 3-ethyl-1-olefin.