DE1931060C3 - Process for the oligomerization of ethylene in the liquid phase - Google Patents

Description

The invention relates to a process for the oligomerization of ethylene in the liquid phase in the presence one containing a cobalt or nickel compound and optionally with an alkyl aluminum compound treated supported catalyst.

Oligomerization processes of this type in which ethylene is converted into olefinic products of higher molecular weight is converted, e.g. B. into the dimer, trimer or tetramer are known per se. For example, ethylene is brought into contact with a catalyst that uses activated carbon as the carrier material contains, on which cobalt oxide is applied. However, the oligomerization product essentially consists only from the dimer and contains only a small proportion of olefinic products with a higher proportion Molecular weight (see US Pat. No. 3,271,474). According to a other known processes, ethylene is oligomerized by means of a catalyst system, which by Reduction of a cobalt salt by means of an organic aluminum compound is obtained. Also in this In this case, however, the oligomerization product consists essentially only of the olefin dimer (cf. NL-OS 66 09 512 and 66 09 513). For many purposes However, it would be of considerable advantage if the reaction product of the oligomerization was a relative would contain high proportion of olefins in the range of higher molecular weights, these being High molecular weight products particularly expediently also have a strongly linear structure.

According to the invention, this technical problem can be solved if the oligomerization in the presence of a special catalyst is carried out. Accordingly, the invention relates to a method for Oligomerization of ethylene in the liquid phase in the presence of a cobalt or nickel compound containing and optionally with an alkyl aluminum compound, in particular a dialkyl aluminum halide treated supported catalyst, which is characterized in that in the presence oligomerized a catalyst whose cobalt or nickel component up to a sulfur content of sulfided at most 5 percent by weight per cobalt compound or 30 percent by weight per nickel compound has been.

Suitable cobalt or nickel compounds for producing the catalysts to be used according to the invention are anhydrous cobalt or nickel salts, which are in a practically anhydrous liquid medium,

ίο like an inert polar organic solvent, can be applied to the carrier material of the catalyst. In most cases a cobalt or Nickel salt with a solubility in an inert polar solvent of at least 0.2 g of salt each

Use 100 g of inert solvent, with salts with a solubility of at least 0.5 g per 100 g of inert solvent are preferred. The Within the scope of the invention cobalt halides, in particular cobalt chloride, as well as nickel halides, nickel oxide and Cobalt acetylacetonate, especially because these compounds are easily accessible.

Sulphidation is likely to produce cobalt or nickel salts, which are cobalt-sulfur bonds or have nickel-sulfur bonds. This sulfidation can be carried out in a manner known per se take place. The cobalt salt in question is preferably used up to a sulfur content of 0.1 to 3 percent by weight Sulfur sulfides, while when using a nickel compound preferably up to a sulfur content from 0.1 to 20 percent by weight is sulfided.

Olefin sulfides are suitable as sulfiding agents, in particular those which contain only carbon atoms and Contain hydrogen atoms and 1 or 2 episulfide atoms. Compounds of this type are alkenyl sulfides

.15 and cycloalkenyl sulfides with up to 10 carbon atoms. Well usable alkenyl sulfides are z. B. Propyler ¹ sulfide, 2-butene sulfide, 1-hexene sulfide and 3-octene sulfide. Cycloalkenyl sulfides which can be used well are, for example, cyclopentene sulfide, cyclohexene sulfide and cyclodecene sulfide. Dialkyl sulfides and dialkyl disulfides, in particular dimethyl sulfide, methyl ethyl sulfide, diethyl sulfide, ethyl butyl sulfide and dibutyl sulfide, are also very suitable for this purpose. In the context of the invention, well applicable dialkyl disulfides are, for example, dim

4S thyl disulfide propyl butyl disulfide and ethyl octyl sulfide.

Other sulfur-containing hydrocarbon compounds suitable for the sulfidation treatment are Alkyl alkenyl sulfides with up to 10 carbon atoms, for example methyl allyl sulfide, ethyl allyl sulfide and

so methyl 2-butene sulfide; aliphatic ones are also suitable Mercaptans with up to 10 carbon atoms such as ethyl mercaptan, propyl mercaptan and cyclohexyl mercaptan; other suitable sulfidating agents are alkyldithiocarboxylic acids, such as thionothiolacetic acid, Thionothiol propionic acid and thionothiobutyric acid; also aliphatic thioketones, such as 2-propanthione, 2-butanthione, 2-hexanthione, 2,4-pentanedithione and cyclohexanthione. In itself, the use is more olefinic Sulphides and other sulphurous hydrocarbons

(10 substances, such as alkyl disulfides, for the storage of Sulfur in metal compounds is known, for example from the publication by P. M. T r e i c h e I and Collaborator in!, Inorganic Chemistry «, 5, 1182 (1966). Inorganic sulfidizing agents can also be used

(> Use 5 sulfur halides, e.g. sulfur monochloride, Sulfur dichloride, sulfur monobromide or sulfur dibromide. According to another Embodiment can be a cobalt or nickel salt

19 3ί

sulfiding and anhydrous at the same time by treating it with a thionyl halide such as thionyl chloride or thionyl bromide. For example, treating the compound CoCh 6 H2O with excess thionyl chloride gives an anhydrous sulfided cobalt salt which is suitable as a component for the catalysts to be used according to the invention

The catalyst support generally consists of a practically silica-free refractory inorganic ι ο see metal oxide, which mainly consists of aluminum oxide. Examples of such carrier materials are

Aluminum oxide, magnesia-aluminum oxide, tungsten oxide-aluminum oxide,

Zirconia-alumina,
Molybdenum oxide-aluminum oxide and
Aluminum oxide-titanium oxide-zirconium oxide.
The carrier material preferably contains at least 75 percent by weight aluminum oxide and in particular at least 90 percent by weight aluminum oxide.

If the catalyst contains a sulphided nickel compound, the carrier material used is a one containing silicic acid refractory oxide is preferred, which contains silica as the main component. In this case there is the refractory oxide containing silica is particularly useful from a mixture of silica and Aluminum oxide with an aluminum oxide content of up to 30 percent by weight and preferably in the range of 5 up to 25 percent by weight.

Particularly favorable results are achieved if the carrier has been calcined for about 6 to 24 hours at a temperature of 450 to 600 ^{° C. before the cobalt or nickel compound is applied.}

A wide variety of working methods can be used for the preparation of the single catalyst according to the invention. According to one embodiment, the cobalt or nickel salt is applied to the carrier material! sulfided. In this case, the sulfidation of the metal salt is carried out in an inert diluent at a temperature in a range from C to 200 ^° C. and at a pressure of 1 to 20 atmospheres.

Inert diluents suitable for this purpose are hydrocarbons if they are not unsaturated have aliphatic bonds, for example hexane, octane, decane, dodecane, cyclohexane, decahydronaphthalene, Benzene, toluene and xylene. After treating the metal salt with the sulfiding agent has, the sulfided metal salt by means of usual so Measures separated from the diluent, for example by filtration, decanting or Evaporation.

According to another procedure, the unsulfided cobalt or nickel compound is first applied to the catalyst support and only then treated with the sulfidizing agent. In this embodiment, the catalyst support is first impregnated with the metal salt, and then the metal salt deposited on the support is sulfided in the same way as it is described above for the metal salt not deposited on a support, for example, by the Carrier-deposited metal salt in an inert diluent at a temperature in a range from hs 0 to 20O ⁰ C and a pressure of 1 to 20 atmospheres with the sulfidating agent. This procedure is preferred for the preparation of the catalysts which can be used according to the invention.

For the production of a nickel oxide catalyst, the nickel oxide is preferably deposited on the support material before the sulfidation treatment, the selected support material, for example silica-aluminum oxide, impregnated with a nickel salt, for example with nickel nitrate, then the impregnated support material is dried and then for the purpose of converting the nickel salt heated in nickel oxide to a temperature in the range from 300 to 700 ^{G C.} According to another embodiment, the hydrous oxides of silicic acid and / or other metals, such as aluminum, can be mixed together with a nickel salt and then the nickel compound can be converted into the by heating in a non-reducing atmosphere at a temperature in the range from 300 to 700 ^° C Transfer nickel oxide. The carrier material loaded with nickel oxide generally contains 0.1 to 20 percent by weight and preferably 3 to 10 percent by weight of nickel oxide, based on the carrier. The nickel oxide deposited on the support can be sulfided by conventional methods.

The preferred procedure is that the carrier material with a solution of the sulfide or not yet sulfided cobalt or nickel compound in a liquid polar organic solvent brings intimately into contact, which preferably no active hydrogen atoms and no unsaturated has aliphatic carbon bonds, d. H. no non-aromatic carbon-carbon unsaturation. Suitable solvents of this type are oxygen-containing hydrocarbons, which apart from carbon atoms and hydrogen atoms only contain 1 to 3 oxygen atoms, e.g. B. oxygen-containing Hydrocarbons with up to 10 carbon atoms, preferably up to 6 carbon atoms, such as Dia'kyl ketones, e.g. B. acetone, methyl ethyl ketone and ethyl butyl ketone; Cycloalkyl ethers, e.g. B. dioxane, tetrahydrofuran, and tetrahydropyran, also acyclic alkyl ethers, such as dimethoxyethane, diethylene glycol dimethyl ether and dibutyl ether. Other suitable polar organic solvents are nitriles, for example Acetonitrile, also dialkylamides, such as dimethylformamide, and dialkylsulfoxides, such as dimethylsulfoxide. In the context of the invention, preference is given to using dialkyl ketones and monocycloalkyl ethers, in particular Acetone and tetrahydrofuran.

The amount of cobalt or nickel compound applied to the catalyst carrier is not critical. Generally 0.1 to 5 percent by weight cobalt or nickel compound is based on that Carrier material, sufficient, amounts of 0.5 to 3 percent by weight being preferred.

The treatment of the catalyst support with the sulfided cobalt or nickel compound can be carried out at any temperature, with temperatures in the range of 20 to 150 ⁰ C are particularly useful. The pressure here is not critical either. In general, pressures in the range of 1 to 50 atmospheres are satisfactory.

After men the catalyst carrier with the treated sulfided metal compound, the carrier with the deposited thereon cobalt or Nickel compound separated from the solvent phase, for example by filtration or decanting.

Extremely active catalyst systems will be

obtained when the carrier loaded with the cobalt or nickel compound also contains an alkylaluminium compound treated, with alkylaluminum halides and trialkylaluminum compounds for preferred for this purpose. Suitable alkyl aluminum compounds are alkylaluminium sesquihalides of the following formula I and alkylaluminum halides and trialkylaluminum compounds of following general formula II

R ₃ Al ₂ X ₃

(II)

In these formulas, R denotes an alkyl group with up to 8 carbon atoms and preferably with up to 4 carbon atoms, X is a halogen atom, preferably chlorine or bromine, π is an integer with a value from 1 to 3. Suitable representatives of alkylaluminum sesquihalides of the formula J are triethylaluminum sesquichloride and triethylaluminum sesquibromide.

Suitable representatives of alkyl aluminum compounds of the above general formula II are alkyl aluminum dihalides, such as ethyl aluminum dichloride, ethyl aluminum dibromide, propyl aluminum dichloride and butyl aluminum dichloride; Dialkyl aluminum halides such as diethyl aluminum chloride, dipropyl aluminum bromide and dioctyl aluminum chlorod; also trialkylaluminum compounds such as triethylaluminum, tripopylaluminum, tributylaluminum and trioctylaluminum. For most applications, alkylaluminum compounds of the formula II, namely alkylaluminum halides, where η is 2 , are particularly preferred, for example dialkylaluminum halides and especially diethylaluminum chloride.

The ratio of cobalt or nickel compound deposited on the substrate to the Alkyl aluminum compound depends in part on the type of alkyl aluminum compound used. the The amount of the alkyl aluminum compounds is chosen so that the ratio of the alkyl aluminum compound provided alkylaluminum bonds per cobalt or nickel atoms in the the metal compound deposited on the carrier material in the range 2: 1 to 10: 1 and preferably in Range from 3: 1 to 6: 1. Although salts of trivalent cobalt have larger amounts of the reducing acting as a divalent cobalt salt, are the The amounts of alkylaluminum compound given above are generally sufficient to allow in the Oligomerization catalysts both salts of divalent cobalt and trivalent cobalt are present.

The alkyl aluminum compound is preferably in an inert diluent which is at reaction temperature and the reaction pressure is liquid with that of the sulfided deposited on the support material Metal connection brought into contact. Suitable reaction diluents are hydrocarbons, which do not contain any aliphatic unsaturated bonds, for example hexane, decane, cyclohexane, Decahydronaphthalene, benzene and toluene. These diluents preferably contain aliphatically saturated ones Alkanes with 6 to 12 carbon atoms in the molecule.

This treatment is expediently carried out at temperatures in the range from -15 ° C to +50 "C. The more reactive trialkylaluminum compounds and alkylaluminum sesquihalides are preferably brought into contact with a cobalt-containing compound deposited on the support material, for example a Temperature between -15 ° C and 0 ° C. The working pressure used is not critical, and pressures in the range of 1 to 50 atmospheres have been found to be useful.
The oligomerization catalyst prepared in this way is then separated off from the diluent in the customary manner, for example by filtration or decanting. In most cases, however, it is very expedient to use a mixture of the diluent and directly for the ethylethylene oligomerization

is to use the catalyst, especially if for the oligomerization anyway a diluent must be used.

The amount of catalyst used for the oligomerization can vary within wide limits. in the generally result in catalyst concentrations of 1 up to 200 percent by weight, based on ethylene, very satisfactory results, with amounts of catalyst from 10 to 100 percent by weight, based on ethylene, are preferred.

If a reaction diluent is used, it can be that for the preparation of the catalyst used diluent must be the same or similar. In certain embodiments of the inventive A proportion of the oligomeric product serves at least in part as a process such reaction diluent, and then less diluent needs to be additionally admixed will. Quantities of up to 5 moles of diluent per mole of ethylene are very useful. Ethylene Oligomerization is generally carried out under inert conditions, so that the reaction space is practical is anhydrous and essentially oxygen-free.

According to one embodiment, the catalyst and the diluent are in an autoclave or fed into a corresponding pressure reactor, then the ethylene is fed, and this reaction mixture is for the desired period of time at the reaction temperature and at the reaction pressure touched. According to another embodiment,

the ethylene feed as a liquid phase solution in a reaction diluent continuously passed through a reaction zone in which the catalyst is arranged. In any case, the Oligomerization at moderate temperatures and

Press so implemented Suitable reaction temperatures are in the range of 20 to 200 ° C and preferably in the range of 20 to 100 ⁰ C. The reaction takes place at or above atmospheric pressure. Typical pressures range from 1 to 80 atmospheres, with pressures in the range from 2 to 35 atmospheres being preferred.

After the reaction has ended, the reaction mixture can be separated and the oligomers formed Products can be isolated in a manner known per se

ho be, for example by fractional distillation, selective extraction, adsorption or similar measures. The reaction diluent, catalyst and unreacted olefin feed are used with advantage in the circuit in the reaction zone

hs returned.

The oligomerization products obtained in this way of ethylene can be used for a wide variety of purposes and represent commercial

chemicals. Oligomers which are still ethylenic in character can be converted into aldehydes by a conventional oxo synthesis, which can then be hydrogenated to the corresponding alcohols by means of conventional catalysts. On the other hand, olefins obtained as reaction products can be converted into secondary and tertiary alcohols by an addition of water catalyzed by sulfuric acid. _{The Q 2} - Cjo alcohols accessible in this way can be ethoxylated by reaction with ethylene oxide in the presence of a basic catalyst, such as sodium hydroxide, to give known detergents, and alcohols of low molecular weight can be reacted with polybasic acids, such as phthalic acid, to form plasticizers be esterified for polyvinyl chloride.

example 1

a) 10 g of a commercially available anhydrous divalent cobalt chloride together with 0.7 g Cyclohexenyl sulfide stirred for one hour at a temperature of 25 ° C. The sulfided cobalt chloride is then filtered off, washed with n-heptane and dried under vacuum at a temperature of 25 ° C. the Elemental analysis confirms that the cobalt chloride has a sulfur content of up to 0.43 percent by weight, based on the cobalt chloride, has been sulfided.

By means of a corresponding procedure, 10 g of cobalt chloride are mixed with 10 g of cyclohexenyl sulfide over the course of 20 Sulphided at a temperature of 25 ° C for hours. The cobalt chloride obtained contains 5.6 percent by weight Sulfur.

b) These sulfided cobalt chlorides and a commercially available cobalt chloride are used as catalysts prepared by adding 50 ml of saturated tetrahydrofuran solution of the cobalt salt in question at a temperature of 25 ° C with a commercially available calcined aluminum oxide. Of the Catalyst is then separated from the tetrahydrofuran solution, washed with n-heptane and with a Solution of 1 g of diethylaluminum chloride in n-heptane brought into contact. This catalyst system will then fed into a stirred autoclave together with n-heptane as solvent. Also will the autoclave is charged with 20 g of ethylene. The autoclave is kept at a temperature of 25 ° C. the reaction conditions used, the selectivity with respect to the formation of the various oligomers and the content of straight-chain products is shown in Table I. The product distribution is determined by gas-liquid chromatography of the olefinic reaction product, and the content of Straight chain compounds are determined by gas-liquid chromatography of the hydrogenated reaction product mixture certainly

55

Table I.

attempt

A.
(Comparison)

(Comparison)

60

Wt% S on CoCl ₂ 0 0.43 5.6 Ethylene, g 20th 20th 20th Response time, hours 2.5 2.5 2.5 Pressure, atm 28 28 28 Ethylene conversion 65 58 0

attempt B. ( Λ (Comparison) (Comparison) Selectivity,% 67.5 0 C ₄ 95.5 16.5 0 c " 4.1 5.8 0 C _K 0.4 3.5 0 C | (i 0 6.7 0 C12-C20 0 Straight chain Product,% 91 - C ₆ 50 94 - C. 30th 96 - Cm - 98 - C12-C20 -

From the table above it can be seen that the most favorable results are obtained by means of the catalyst composition can be achieved by experiment B, the cobalt component of less than 5 percent by weight has been sulfided.

Example 2

a) 10 g of a commercially available anhydrous divalent cobalt chloride are added for 24 hours stirred at a temperature of 77 ° C together with 5 g of S2CI2 in a solution of carbon tetrachloride. That sulfur-containing cobalt salt thus obtained is then filtered off, washed with n-heptane and held for 3 hours dried in vacuo at a temperature of 25 ° C. Elemental analysis confirms that the cobalt chloride has been sulfided to a sulfur content of 0.45 percent by weight

A sulphidated one becomes a sulphided one by using sulfur dichloride (SCI2) Cobalt chloride produced, which contains 0.06 percent by weight sulfur.

b) These sulfur-containing cobalt salts are deposited on a carrier material by each brings a saturated solution of the salt in acetone into contact with calcined aluminum oxide and then the cobalt salt deposited on the support material according to the procedure of Example Ib Diethylaluminum chloride treated. In this way, catalysts are obtained which each have 1 Contains percent by weight of cobalt metal on aluminum oxide. These catalysts are then used for the Oligomerization of ethylene used in an autoclave In Table II below are the cobalt salts used in each case, the reaction conditions, the selectivity of the various oligomers Products and the percentage of straight-chain reaction products compiled

Table II S ₂ Cl ₂ SCl ₂ Sulfiding agents 0.45 0.06 Wt% S on CoCl ₂ 10 10 Amount of catalyst, g 20th 20th Ethylene, g 28 28 Pressure, atm 2.5 2.5 Response time, hours 54 61 Conversion in%

l-orlscl / uiiu 83.2 Product,% 100 85.5 Selectivity,% 8.5 88 7.3 C, 3.0 93 2.6 c " 1.8 94 1.5 C _x 1.2 96 1.0 C ₁₀ 2.3 98 2.1 C ₁ , Example 3 C 14 "Ci (I. 100 Straight chain 90 C, 94 C ₆ 96 C ₈ 98 C ₁₀ 98 C ₁₂ ^ CI4-C20

Table III 53.5 Selectivity,% 16.5 C ₄ 10.6 C ₆ 6.9 C ₈ 53 C ₁₀ 3.0 C ₁₂ 2.0 Cm 1.5 C ₁₆ 10 C ₁₈ 41 Catalyst, g 15th Heptane, g 25th . Ethylene, g 21-28 Temperature, "C 2.5 Pressure, atm 33 Response time, hours 0.8 Ethylene conversion, % C20 92 Straight-chain product, % 98 C ₄ Cs - C20

.1 °

a) 238 g of divalent cobalt chloride hexahydrate are stirred for 3 hours at a temperature of 25 ° C with 714 g of thionyl chloride, and then heated for 15 hours on a water bath. This sulfided cobalt salt is then filtered, washed with heptane and 3 hours (5 mm Hg) dried under vacuum at a temperature of 100 ⁰ C. Elemental analysis determined that the cobalt chloride had been sulfided to a sulfur content of 1.4 percent by weight.

b) A saturated acetone solution of this sulfided cobalt chloride is then brought into contact with calcined aluminum oxide. In this way, a catalyst is produced which contains 1.4 percent by weight of cobalt metal, based on the support material. 10 g of the support material with a silfidized cobalt compound are then treated for 5 minutes at a temperature of 20 ° C. with a solution of 1 g of diethylaluminum chloride in heptane. This catalyst is used for ethylene oligomerization in an autoclave. Table III below shows the amounts of the reaction components used, the reaction conditions, the selectivity with regard to the formation of the various oligomers and the proportion of straight-chain compounds in the reaction product.

Example 4
(only for comparison)

20 g of activated charcoal (Norit A) are mixed with 5 aliquots of 100 ml each of a succession then washed 1.6 N nitric acid at a temperature of 8O ⁰ C and treated with 500 ml of distilled water. It is then dried, the thus treated active carbon for 15 hours in air at a temperature of 120 ° C and 3 hours at a temperature of 300 ⁰ C in a nitrogen atmosphere. The dried activated carbon is then stirred for 30 minutes at a temperature of 25 ^° C. with a solution of 30 g of divalent cobalt chloride hexahydrate in 20 ml of water. After filtering off, drying is carried out for 1 hour at 120 ^° C. in the air and for 30 minutes at 300 ^° C. in a nitrogen atmosphere. It is determined by elemental analysis that this catalyst contains 17.9 percent by weight cobalt.

11.7 g of the catalyst are fed together with 4 ml of diethylaluminum chloride and 60 ml of n-heptane into an autoclave with a capacity of 300 ml. The autoclave is l / ₄ hours' is held on a Timperatur 25-30 ⁰ C, while simultaneously continuously 123 g of ethylene are fed to maintain a pressure from 20 to 27 atmospheres. The ethylene conversion is 98%. Table IV below shows the selectivity with respect to the formation of the various oligomers and the proportion of straight-chain products.

Table IV

Oligomer

55

60 selectivity

Straight product

.15

40

C ₄ 92.7 62 C ₆ 6.6 62 C ₈ 0.6 37 C ₁₀ 0.2 9 Example 5

a) 4.2 g of anhydrous nickel dichloride are ^{stirred for 7 hours at a temperature of about 110 °} C. with a solution of 0.9 ml of cyclohexene episulfide in 25 ml of toluene. The sulfided nickel chloride is then filtered off, washed with n-heptane and dried in vacuo at a temperature of 25 ° C. The elemental analysis confirms that the nickel dichloride has been sulfided to a sulfur content of 0.4 percent by weight. 1 g of this sulfided nickel chloride is then for 48 hours at about 110 ° C with 10 of a commercially available calcined aluminum oxide in 25 ml of toluene g brought into contact with the catalyst so obtained is then separated from the solution and with 1.0 g of diethylaluminum chloride in 10 ml of n-heptane treated. The catalyst system obtained in this way is then introduced into a stirred autoclave. In addition, the autoclave is charged with 15 g of ethylene. The reaction conditions used and the results of this experiment are summarized in Table V under Experiment A below

b) 700 ml of a tetrahydrofuran solution, which with anhydrous nickel chloride is saturated, will be 4 days brought into contact with 20 g of aluminum oxide at a temperature of 25 ° C.

Gnated carrier material is then separated and for 6 hours at a temperature of 25 ° C im Vacuum dried (2 mm Hg). Elemental analysis confirmed that the carrier material was 1.5 percent by weight Contains nickel, calculated as elemental nickel.

4 g of this nickel-laden support material are treated with 0.16 ^ cyclohexene episulfide in 16 ml of toluene ^{at a temperature of 110 ° C. for 1/2 hour.} The sulfided catalyst is then filtered off, washed with heptane and dried in vacuo. The elemental analysis confirms that the catalyst contains 0.3 percent by weight of sulfur or 20 percent by weight of sulfur, based on the nickel content. 1 g of the sulfided catalyst is then treated with 2 molar equivalents of diethylaluminum, based on the nickel content, in 2 ml of heptane. The solution containing the catalyst and a further 30 ml of heptane are then introduced into an autoclave. The autoclave is also charged with 15 g of ethylene. In Table V below, under Experiment B, the reaction conditions used and the results obtained are compiled.

c) 1 g of the support material loaded with nickel according to section b), but which is not sulfided treated with 2 molar equivalents of diethylaluminum chloride in 2 ml of n-heptane. Also the catalyst obtained in this way is then used for the oligomerization of ethylene (comparative experiment). The one with it The results obtained are shown in Table V under Experiment C below.

Table V

attempt
AWAY

(Comparison)

Wt% SaufNiCl ₂ 0.4 20th 0 Ethylene, g 15th 15th 28 Response time, hours 2 3 1 Pressure, atm 21-42 28-35 28-35 Ethylene conversion,% 33 81 90 Selectivity,% C ₄ 61.7 60 85 C ₆ 24.8 22nd 11th C ₈ 8.5 8th 4th 2.7 4th traces CI ₂ -C 20 2.3 6th - Linearity,% C ₄ 100 100 100 C ₆ 78 95 55 C ₈ 69 90 12th C, o 60 95 - C12-C20 70 97 -

Example 6

a) 30 g of silica-aluminum oxide with an aluminum oxide content of 25 percent by weight and a specific surface area of about 200 m ² / g are impregnated at a temperature of 25 ° C. with a solution of 6 g of nickel nitrate in 27 ml of water. The impregnated support material is then dried and calcined in air for 4 hours at a temperature of 525 ° C. The catalyst obtained in this way contains 3.6 percent by weight of nickel, calculated as elemental nickel, based on the support material of silica-aluminum oxide.

For the sulfidation, 10 g of the support material nickeloxydhaltigen for 5 hours at a temperature of 50 ⁰ C with 0.1 g of dimethyl disulfide in 30 ml of n-heptane treated. The catalyst is then filtered off, treated with n-heptane and dried at a temperature of 25 ° C. in vacuo. The elemental analysis confirms that the catalyst has been sulfided up to a sulfur content of 0.29 percent by weight, based on the support material.

b) According to a corresponding procedure, a catalyst is prepared which has nickel oxide contains deposited on a support material made of silica-aluminum oxide, the nickel content being 10 Weight percent is. Then it is sulfided as described in section a), whereby one A catalyst is obtained which has 2 percent by weight sulfur, based on the support material.

c) Using these catalysts, a series of oligomerization attempts are carried out, wherein each reactor is charged with 50 g of ethylene, 60 ml of heptane and 5 g of the catalyst in question. In the Table VI below shows the reaction conditions used and those obtained Results compiled. Experiment A relates to the non-sulfided, nickel oxide-containing Catalyst of a). Experiment B relates to the sulfided, nickel oxide-containing catalyst of a), and Experiment C relates to the sulfided, nickel oxide-containing catalyst from b).

Table VI

attempt B. C. A. (Comparison) catalyst composition 3.6 10 Weight percent nickel 3.6 0.29 2 % Sulfur by weight 0 Reaction conditions 150 150 Temperature, "C 150 3 3 Time, hours 3 28 28 Pressure, atm 28 1.9 2.1 Grams of oligomer / 3.2 Grams of catalyst / Hours. Selectivity,% 42.7 57.4 C ₄ 85.4 28.2 23.0 C ₆ 9.6 12.6 9.0 C ₈ 2.3 7.0 3.5 Cio 1.1 4.0 3.0 C ₁₂ 0.6 2.8 2.1 C ₁₄ 0.5 1.3 1.5 C ₁₆ 0.3 0.8 0.5 C ₁₈ 0.2 0.6 - C20 - Linearity of the Oligomer product 100 100 C ₄ 100 87 80 C ₆ 81 80 65 C ₈ 32 72 5σ Cio 4th 78 72 C ₁₂ 1 82 91 C ₁₄ 9 88 90 C ₁₆ 0 89 95 C ₁₈ 0 90 - C ₂₀ -

Claims (3)

Patent claims: 1. Process for the oligomerization of ethylene in the liquid phase in the presence of a cobalt or Nickel compound containing and optionally with an alkyl aluminum compound, in particular a dialkyl aluminum halide, treated supported catalyst, characterized in that that one oligomerizes in the presence of a catalyst, its cobalt or nickel component up to a sulfur content of at most 5 percent by weight per cobalt compound or 30 Percentage by weight per nickel compound has been sulfided. 2. The method according to claim 1, characterized in that one is in the presence of a catalyst oligomerized. its cobalt component up to a sulfur content of 0.1 to 3 percent by weight has been sulfided. 3. The method according to claim I, characterized in that one is in the presence of a catalyst oligomerized, the nickel component of which has a sulfur content of 0.1 to 20 percent by weight has been sulfided.