DE2228262C3 - Process for the production of higher olefins - Google Patents

Description

oxide, which has at least 0.1 percent hydroxyl groups

contains, and carries out at least one metal of Group I of the Periodic Table and at one Hydroxyl group content of the alumina works from 0.1 to 1 percent in the presence of hydrogen. This process gives the desired higher olefins with a narrow molecular weight distribution, Surprisingly, it has now been found that the efficiency of the DT-OS 20 22 330, especially with regard to the content of α-olefins, can be improved considerably, if the catalysts used there are subjected to a certain calcination and aging process.

The invention thus relates to a process for the production of higher olefins by polymerizing ethylene at temperatures from 30 to 220 ^° C. in the presence of a catalyst, the aluminum oxide

The invention relates to a process for the production of higher olefins and a catalyst for carrying it out of the procedure.

Higher olefins are valuable raw materials, e.g. B. for the production of plasticizers and detergents. They are so far on an industrial scale by breaking down waxes and dehydrating the resulting Ti-paraffins or, according to Ziegler, by polymerizing low molecular weight olefins using made of organic aluminum compounds as catalysts.

However, the degradation of waxes requires severe reaction conditions and gives products with a broader range

Molecular weight distribution and low content 40 with a content of at least 0.1% by weight

on the desired higher olefins. This method thus shows in terms of yields, the Process performance and the purity of the end products numerous deficiencies. Also paraffin dehydration requires severe reaction conditions and gives end products, mostly medium-sized double bonds exhibit. On the other hand, the Ziegler method presents some difficulties because the catalyst is extremely sensitive to air and moisture and the products have a Poisson molecular weight distribution exhibit. In order to limit the molecular weight distribution to a certain range, many improvements have been made proposed, which, however, necessarily complicate the process.

It is already known that alumina activates the polymerization of ethylene and under certain circumstances Conditions butene or wax supplies (S h i b a in "Nippon Kagaku Zasshi [Journal of the Chemical Society of Japan, Pure Chemistry Section] ”, Vol. 76 6b [1955], p. 1046; Amaraiya in "Advances in Catalysis", Vol. 17, p. 132).

It is also known that ethylene can be used over a catalyst which consists essentially of an alkali metal with an ordinal number of at least 11 and an aluminum oxide treated at a higher temperature as an adsorbent, to form a solid mass can polymerize (US-PS 28 87 472).

cent hydroxyl groups and at least one metal of the Contains group I a of the periodic table, and, with a hydroxyl group content of 0.1 to 1 percent, in the presence of hydrogen, and optionally in the presence of a solvent, which is characterized is to use a catalyst obtained by calcining and aging the alumina in a mixture with 0.1 to 50 percent by weight, based on the aluminum oxide, of the metal (or the Metals) in an inert atmosphere at temperatures around or above the metal melting point has been made.

In the process of the invention, surprisingly, only the desired higher ones are obtained Olefins with a high content of u-olefins.

In the process of the invention, therefore, the amount of ethylene used is relatively small, and the individual Process steps are easy to carry out, so that the production of higher olefins is economically advantageous runs.

The calcination and aging conditions in the preparation of the catalyst are great Influence on the catalyst activity and the molecular weight distribution of the product obtained. Into the in particular the type of mixing of the catalyst components or the type of application of the alkali metal on the aluminum oxide carrier as well as the Calci The aging and aging temperature have a major influence

going the catalytic activity, the content of u-olefins and the molecular weight distribution of the End products. At calcining and aging temperatures below the alkali metal melting point the catalyst activity is low and the content of α-olefins in the end products is low. This is based probably that the metals are only insufficiently distributed on the aluminum oxide. For calcination and aging temperatures around or above the metal melting point are achieved on the other hand high catalyst activity, so that higher olefins with a high content of u-olefins with large Let implementation speed be established.

The hydroxyl group content of the aluminum oxide, the type of metal or the metals of group Ia of the periodic table and the mixing ratio of the metals are also of great influence the catalyst activity and the content of α-olefins in the end products.

The catalyst components are used for calcination or aging by stirring, shaking or evaporation over a certain period of time at the set temperature in an inert atmosphere, z. B. in helium, argon, neon or nitrogen, mixed together.

The calcining and aging of the catalyst components can e.g. B. be carried out in such a way that one mixes the ingredients, heated the resulting mixture to the desired temperature and then holds at this temperature for a certain period of time. Another method is that while the heating of the aluminum oxide adds the metal or vice versa and then the catalyst components hold at the desired temperature for a certain period of time. You can also use the aluminum oxide Heat to the desired temperature and then add the metal or vice versa and then hold the catalyst components for a certain time at this temperature.

The catalysts used in the process of the invention are pale blue or pale yellow and should be are not brought into contact with air. No lines appear in the X-ray diagram Indicate aluminate or a metal from Group Ia of the Periodic Table. The absence of the Metal lines is likely caused by the molecular dispersion of the metals on the alumina.

Also the quantitative ratio of the metal from group Ia of the periodic table to aluminum oxide is of great influence on the reaction rate, the catalytic activity and the Content of α-olefins in the end products. With high alkali metal contents, both the reaction rate and the content of α-olefins in the end products is low. The relationship from metal of group Ia of the periodic table to aluminum oxide can vary within wide limits, it is 0.1 to 50 percent by weight, based on the aluminum oxide.

When using an aluminum oxide with a content of 0.1 to 1 percent by weight of hydroxyl groups higher olefins are only obtained when hydrogen is present at the same time. Is the hydroxyl group content below 0.1 percent by weight, either in the presence or in the absence of hydrogen, only wax or solid is obtained Polyethylene. At contents above 1 percent by weight, the presence of hydrogen is not essential required, because regardless of its use, only higher glaefins are created in any case.

The catalyst used in the process of the invention contains at least one metal from group Ia of the periodic table and aluminum oxide a content of at least 0.1 percent by weight hydroxyl groups. Becomes one of the two catalyst components Used on its own, there is no polymerization of the ethylene. When combined Surprisingly, however, an oligomerization reaction of the two components takes place.

The aluminum oxide contains at least 0.1 percent by weight of hydroxyl groups by removing excess water under reduced pressure.

Although the mechanism of the reaction is still completely unclear, it is clear that the amount of Hydrogen plays an important role in terms of catalyst activity and molecular weight distribution the end product plays.

The amount of hydroxyl groups in aluminum oxide is determined according to the method described in "Journal of Catalysis", Vol. 7 (1967) P. 342, described method.

The process of the invention can be carried out in the presence or absence of solvents will. Preferred solvents are aliphatic hydrocarbons, especially hexane and heptane.

The catalyst is used as a slurry in the process according to the invention.

If the reaction is carried out continuously by continuously feeding the starting materials into the reaction vessel, better ones are obtained Results than with discontinuous operation.

The method of the invention is to achieve a high yield of higher olefins at a reaction temperature of about 30 to 220 ° C, preferably at about 50 to 200 ⁰ C is performed. The end products suitable for the production of plasticizers, detergents and aliphatic carboxylic acids have a high content of -olefins and essentially consist of unbranched olefins, as can be seen from the IR spectra.

The examples illustrate the invention.

In the examples, a 1 1 capacity stainless steel autoclave is used, which is equipped with an electromagnetic Stirrer is equipped. First, the air in the autoclave is displaced by nitrogen, then the specified amounts of the catalyst and the solvent are fed in and then ethylene is said for the specified time at the specified temperature under the pressure also specified polymerized. The reaction products are detected with the aid of a hydrogen flame ionization detector analyzed by gas chromatography; the content of α-olefins is measured in the IR spectrometer (Kogyo Kagaku Zasshi in "Journal of the Chemical Society of Japan, Industrial Chemical Section", Vol. 73 [1970], Pp. 505 to 508).

example 1

30 g of aluminum oxide with a content of 0.1 percent by weight To hydroxyl groups is added 2.0 g of potassium metal and the resulting mixture is calcined with stirring for 1 hour at 100 ° C. in a nitrogen atmosphere and aged. In present a suspension of 4.0 g of the catalyst obtained in 200 ml of n-heptane is ethylene for 30 minutes

120 ° C obtained under an ethylene pressure of 90 kg / cm ² . The results obtained are shown in Table I.

polymerized. The polymerization rate of the compiled.

Ethylene is 5.1 g / (g catalyst-hour). The _n . . . . ,, ..,

obtained higher olefins consist of 47.8% of d e ι s ρ ι e i c., to ι _

α-olefins; in detail, the following 5 ^and comparative examples 1 to are produced

higher olefins: The catalysts listed in Table 1 and

Q-C olefins 4.24 percent by weight solvent are fed into the autoclave,

C o-cL-Olenne 9476 percent by weight ™ ^{Γ Αΐ1ι} * ^{1εη un} i ^er _r ^den ! » | ^{but le l on gfhrte} "

C J-C ^ olefins 1.0 weight percent conditions according to Example 1 is polymerized.

- "ίο The results obtained are summarized in Table 1-

Olefins with more than 22 carbon atoms are not provided.

Table 1

Catalyst Calcinie- Kata- Solution Reaction Pressure

Ingredients OH calcination and analyzer medium

Group and aging

Alkali metal AKOj content of the aging time

Al ₂ Oj temperature

(g) (g) (%) (° C | (h) (g) (ml) (kgcrrri

Example 1 K 2.0 30.0 0.1 100 C, l 4.0 n-heptane 90 (10 weight

200 percent H ₂ )

Comparative K 2.0 30.0 0.1 60 0.1 4.0 n-heptane 90 (10 weight example 1 200 percent H ₂ )

Example 2 Na 2.0 30.0 1.3 140 0.1 4.0 n-heptane 90

200

Comparative Na 2.0 30.0 1.3 95 0.1 4.0 n-heptane 90

example 2 200

Example 3 Li 2.0 30.0 1.3 250 0.1 4.0 n-Heptane 90

200

Comparative Li 2.0 30.0 1.3 180 0.1 4.0 n-heptane 90

example 3 200

Example 4 Rb 2.0 30.0 1.3 100 0.1 4.0 n-heptane 90

200

Comparative Rb 2.0 30.0 1.3 space 0.1 4.0 n-heptane 90

example 4 temperature 200

Example 5 Cs 2.0 30.0 1.3 100 0.1 4.0 n-heptane 90

200

Comparative- Cs 2.0 30.0 1.3 space 0.1 4.0 n-heptane 90

example 5 temperature 200

Example 6 K 1.9 30.0 1.3 140 0.1 4.0 n-heptane 90

+ Na 0.1 200

Comparative K 1.9 30.0 1.3 35 0.1 4.0 n-heptane 90

Example 6 + Na 0.1 200

Example 7 K 1.9 30.0 i, 3 100 0.1 4.0 n-heptane 90

+ Na 0.1 200

Comparative K 1.9 30.0 1.3 60 0.1 4.0 n-heptane 90

Example 7 + Na 0.1 200

Example 8 Cs 2.0 30.0 1.8 100 0.1 4.0 n-heptane 90

200

Comparative- Cs 2.0 30.0 1.8 space 0.1 4.0 n-heptane 90

example 8 temperature 200

Example 9 K 1.5 30.0 1.8 140 0.1 4.0 n-heptane 90

200 Example 10 K 10 30.0 1.8 140 0.1 4.0 n-heptane 90

200 Example 11 K 2.0 30.0 1.8 300 0.1 4.0 n-heptane 90

200 Example 12 K 0.2 30.0 1.3 140 0.1 4.0 n-heptane 90

+ Na 1.8 200

Comparative K 0.2 30.0 1.3 35 0.1 4.0 n-heptane 90

ex. 9 + Na 1.8 200

continuation

Response icmpcrature

CC)

Reaction rate reaction time g (end products)

g (catalyst) -hour .i-olefin composition of the higher olefins content (weight percent)

C ₁₀ -C ₁ .

C ₂ J or more

example 1
Comparative example 1
Example 2
Comparative example 2
Example 3
Comparative example 3
Example 4
Comparative example 4
Example 5
Comparative example 5
Example 6
Comparative example 6
Example 7
Comparative example 7
Example 8
Comparative example 8
Example 9
Example 10
Example 11
Example 12
Comparative example 9

120 120

120 120

120 120

120 120

120 120

120 120

120 120

120 120

120 120 120 120 120

0.5 0.5

0.5 0.5

0.5 0.5

0.5 0.5

0.5 0.5

0.5 0.5

0.5 0.5

0.5 0.5

0.5 0.5 0.5 0.5 0.5

5.1 2.8

4.1 1.5

1.8 0.87

15.1 7.7

17.8 9.0

8.2 3.8

13.8 10.5

20.5 14.8

28.0

10.8

600

6.2

6.2

57.8
20.8
65.2
37.0
28.7

4.24
3.31

2.85
3.05

5.64
6.10

11.8
14.1

8.7
10.1

7.90
11.51

12.70
11.07

23.79
17.10

17.79
8.17

11.86
7.90

11.51

94.76 95.85

97.05 96.75

94.26 93.80

83.9 78.6

79.0 78.0

88.19 77.51

75.69 77.87

61.70 71.89

73.19 65.32 63.96 88.19 77.51

1.0 0.84

0.10 0.20

0.10 0.10

3.2 5.8

10.5 Π, Ι

3.91 10.8

10.70 9.89

15.21 11.01

9.02 15.81 23.08

3.91 10.8

0 0

0 0

0 0

1.1 1.5

1.8 0.8

0 0.18

0.91 1.17

0.20 0

10.70 1.10 0 0.18

Test report
Comparative experiments 10 and 11

Comparative experiments were carried out according to Example 1 with a catalyst listed in Table II The results are summarized in Table II.

It can be seen from the table that none of the catalysts with an alkali metal (potassium) in an amount of 0.1 to 50 percent by weight, based on the weight of Al ₂ O ₃ , catalyzes the formation of α-olefins

table Il catalyst
Components
Alkali metal K Al ₂ O ₃ OH group
content of Al-O ₃ Calcination
and aging
temperature Calcination
and aging
time catalyst Solution
medium No. (G) (G) (%) CC) lh) (G) (ml) 0.02 30th 1.8 300 0.1 4.0 n-heptane
200 10 17th 30th 1.8 300 0.1 4.0 n-heptane
200 11th 509 683/21

9 10

continuation

Rcaklions- Reaklions- Reaktioiisgeschtt'indigkcil ./- Olefin- Composition of the higher oleline

pressure temperature time g (end products) content (weight percent)

g (catalyst) -Skinde

(%) C ₁₁ -Q, C ₁₁₁ -C ₁₁ , C ₁₁₁ -C ,,, C ₂ ,

(kg / cm-) ("C) lh) 0 90 120 0.5 1, 90 120 0.5

0 0 0 0 0 0 2.4 41.5 31.6 25.3

Claims (1)

Claim: Process for the production of higher olefins by the polymerization of ethylene at temperatures of 30 to 220 ° C in the presence of a catalyst, the aluminum oxide with a content of at least 0.1 percent by weight of hydroxyl groups and at least one metal from Group I of the Periodic Furthermore, obtained in the polymerization of ethylene in the presence of a catalyst in the essentially consists of an alkali metal on anhydrous aluminum oxide with a large surface area, at the same time a solid polymer having a molecular weight greater than about 1,000 and a liquid Polymer having about 8 to 18 carbon atoms and a molecular weight of up to about 250. The catalyst is produced by System contains, and, in the case of a hydroxyl group, that the aluminum oxide carrier is treated with alkali metal salts or alkali metal hydroxides neutralized and so converted into a promoter and the treated Aluminum oxide then caicinated (JA-PS 23 322/70). Finally, in DT-OS 20 22 330 a process for the production of higher olefins with a narrow molecular weight distribution by polymerization of ethylene in the presence of aluminum oxide-containing catalysts and optionally a solvent be content of 0.1 to 1 percent, in the presence of hydrogen, and optionally in the presence of a solvent, characterized in that that one uses a catalyst obtained by calcining and aging the Aluminum oxide in a mixture with 0.1 to 50 percent by weight, based on the aluminum oxide, of the metal (or metals) in an inert atmosphere at temperatures around or above of the metal melting point has been established. 20 wrote, which is characterized by the fact that one the polymerization at temperatures from 30 to 220 ⁰ C with a catalyst system made of aluminum