RU2553995C1 - Method of producing ethylene oligomerisation catalyst system component, catalyst system component, ethylene oligomerisation catalyst system based on said component and ethylene oligomerisation method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: catalyst system component is obtained via mechanical activation of a solid mixture with the ratio of 2-ethyl hexanoate of group I metal:CrCl₃>1:1 and heating the activated mixture to obtain the desired product. The ethylene oligomerisation catalyst system contains an organoaluminium compound of general formula AlR₃, a complexing agent, a modifier, a solvent and a chromium-containing component obtained using the disclosed method. The ethylene oligomerisation method is carried out in the medium of a hydrocarbon solvent at temperature of 40-95°C and ethylene pressure of 1-5 MPa in the presence of said catalyst system.

EFFECT: simple method of producing a component of catalyst systems for oligomerising olefins, high output of the product when oligomerising ethylene to hexene-1, high selectivity of the process and purity of hexene-1, low probability of secondary reactions.

4 cl, 1 tbl, 16 ex

Description

The invention relates to the field of chemistry of polymerization processes, specifically to methods for producing components of catalytic systems for the oligomerization of olefins, in particular trimerization and tetramerization of ethylene. The aim of the invention is to develop a method for producing components of catalytic systems used in the processes of oligomerization of ethylene (mainly in hexene-1) by catalytic oligomerization of ethylene in the presence of complex organometallic compounds, including tris (2-ethylhexanoate) chromium and trialkylaluminium. The invention can find application in various industries, especially in large-scale synthesis of ethylene-propylene copolymers, hexene-1 polymers and oligomers, olefin oxides, and other applications.

The modern petrochemical and chemical industries are largely based on the use of lower olefins (ethylene and propylene) as feedstock for various kinds of syntheses. Butene-1, hexene-1 and octene-1 are the demanded monomers of the olefin series, attention to which has been constantly increasing over the past 20 years. Although in industry these monomers can be isolated from the butane-butylene fraction of cracking gases or the pyrolysis of hydrocarbon feedstocks, as well as from products formed in the Fischer-Tropsch processes, the most promising potential industrial process for producing butene-1, hexene-1 and octene-1 is polymerization degree of purity is the catalytic oligomerization of ethylene. In recent years, due to the expansion of production volumes and the brand composition of copolymers of ethylene and / or propylene with butene-1, hexene-1 and octene-1 with an improved set of properties, the need for these α-olefins has increased.

The catalytic oligomerization of ethylene into higher α-olefins can be carried out either on metals or metal oxides on supports (A. Takahashi et al., Kogyo Kagaku Zasshi. 1963. v.63. P.973, US patent No. 3113166, C08F 10/00 , 1963; No. 4000211, C07C 3/10, 1976), or in the presence of Al (C ₂ H ₅ ) ₃ (KW Egger. Trans. Farad. Soc. 1971. v. 67. No.575. P.2636, patent US No. 4484016, C07C 2/04, 1984; Japanese Patent No. 61122230, C07C 2/30, 1986), or in the presence of complex organometallic catalysts. The first two methods are characterized by low productivity and selectivity for butene-1.

The easiest and cheapest way to obtain butene-1, hexene-1 and octene-1 polymerization grade of purity today is the method of catalytic oligomerization of ethylene in the presence of catalysts based on titanium, chromium or nickel compounds in combination with aluminum trialkyls and various modifiers. Over the past 30 years, researchers in various countries of the world have been working on this very problem, including researchers at the Institute of Problems of Chemical Physics of the Russian Academy of Sciences (US patents Nos. 5030790, C07C 2/24, 1991; No. 5037997, C07C 2/24, 1991, etc. .).

One of the objectives of this invention is to develop a method for producing a component of catalytic systems for the oligomerization of ethylene, mainly in hexene-1, based on tris (2-ethylhexanoate) chromium, from which, if necessary, pure tris (2-ethylhexanoate) chromium can be isolated , which is used as the main component of catalysts of various chemical processes. In particular, this compound is widely used in the industrial process of trimerization of ethylene in hexene-1 [Dixon J.T. et al. Organomet. Chem. 2004. V.689. Number 23. P.3641) and in the tetramerization of ethylene, mainly in octene-1 (Blann K., Bollman A., De Bod H., Dixon JT, Killian E., Nongodlwana P., Maumela MC, Maumela H., McConnell A .E., Morgan DH, Overett MJ, Pretorius M., Kuhlemann S., Wasserscheid P. // J. Catal. 2007. V.249. No. 2. P.244).

One of the industrial methods for producing a component of catalytic systems for the oligomerization of olefins is chromium (III) carboxylates [Mehrotra R.C., Bohra R. Metal carboxylates. Academic Press Inc. (London) Ltd. 1983. 396 pp.] And, in particular, Cr (2-ethylhexanoate) ₃ ("Cr (EH) ₃ ") ethyl hexanoate usually includes a boiling step of chromium (III) acetate with an excess of organic (in particular 2-ethylhexanoic) acid. The resulting acetic acid, excess organic acid and water are usually removed as completely as possible by pumping the reaction mixture in vacuo. Chromium (III) carboxylates are also obtained by reduction of chromium trioxide in the presence of an excess of carboxylic acid, which in this case also acts as a reducing agent. Typical disadvantages of these methods are that the products usually contain residual amounts of carboxylic acid and water. This degrades the quality of the products, as some possible applications of Cr (EH) _{3 are} extremely sensitive to traces of proton-donating contaminants (water, acids). The formation in the processes under consideration and the presence in the products of uncontrolled quantities of polynuclear chromium carboxylates can lead to a decrease in the activity and selectivity of catalytic systems for the oligomerization of olefins based on them [O. L. Sydora, RD Knudsen, EJ Baralt. US Pat. Appl. 2013/0150605 A1, Int. C1. C07F 11/00 (June 13, 2013. Preparation of transition metal carboxylates)].

The specified component of the catalytic systems is also obtained by a multistage exchange reaction - the interaction of sodium ethyl hexanoate with hydrated chromium nitrate during prolonged boiling with an excess of 2-ethylhexanoic acid (Rb Steele, Fair Oaks, A. Katzakian, JJ Scigliano, EE Hamel. US Pat. 3838101, Sept. 24.1974). The process is carried out under heterogeneous conditions and the degree of completion of the process does not have clear criteria. It should also be noted the complexity of the selection of the target product.

Closest to the proposed technical solution is the method according to which the component of the catalytic systems of ethylene oligomerization, mainly in hexene-1, is obtained by the reaction of anhydrous NaEH and CrCl ₃ (TTF) ₃ in absolute THF at room temperature by stirring for a long time (24-96 h) followed by removal of the solvent and volatiles in vacuo, extraction of the resulting mixture with a hydrocarbon solvent, removal of excess NaEH [OL Sydora, RD Knudsen, EJ Baralt. US Pat. Appl. 2013/0150605 A1, Int. Cl. C07F 11/00 (June 13, 2013. Preparation of transition metal carboxylates)] (prototype). In accordance with the specified method, the use of a volatile fire hazardous organic solvent (tetrahydrofuran), long-term (24-96 h) stirring of the heterogeneous reaction mixture, distillation of the solvent in vacuo, and difficult purification of the products thus obtained from excess NaEH is required to obtain the target products. The products resulting from this process are (due to the presence of residues of sodium ethyl hexanoate and a solvating solvent) viscous mixtures that are inconvenient to handle. All of the above operations significantly complicate and increase the cost of obtaining the target product.

The objective of the invention is to develop a method for producing a component of catalytic systems of ethylene oligomerization, mainly in hexene-1, by the method of solid-phase mechanochemical synthesis, as a result of which it is possible to obtain a finished solid product with increased and long-term catalytic activity, which can be stored or used as a solution in hydrocarbon solvents for oligomerization (trimerization, tetramerization) of ethylene to higher alpha olefins. The objective of the invention is also to develop a process for the oligomerization of ethylene to higher alpha olefins in a hydrocarbon solvent medium using catalytic systems based on the obtained components in combination with organometallic compounds.

Currently, in connection with the development of "green chemistry" (green chemistry) of great interest are the processes of interaction of solid starting components in the absence of solvent (solventless reactions) (GWV Cave, C. L. Raston, JL Scott, J. Chem. Soc., Chem. Commun., 2001, No. 21, 2159). In many cases, the method of mechanical activation is used to accelerate such processes (E.G. Avvakumov, Mechanical methods for the activation of chemical processes, Nauka, Novosibirsk, 1986, 297 pp .; K.G. Myakishev, V.V. Volkov, Preprint 89-12 , Institute of Inorganic Chemistry SB RAS, Novosibirsk, 1989, 42 pp .; VV Boldyrev, Usp. Chemistry, 2006, 75, 203 [Russ. Chem. Rev., 2006, 75, 177]; MK Beyer, H. Clausen-Schaumann, Chem. Rev., 2005, 105, 2921; P. Yu. Butyagin, Usp. Chemistry, 1994, 63, 1031 [Russ. Chem. Rev., 1994, 63, 965]). Mechanical action leads to the mixing of reagents at the molecular or cluster level and their subsequent interaction. A local increase in temperature at the points of impact of the elements of the activating nozzle also contributes to an increase in the mobility of ions and acceleration of the interaction process.

The tasks are solved by the method described below for the preparation of a component of ethylene oligomerization catalytic systems, according to which the preparation of these components is carried out by reacting the starting solid reagents - group 1 metal 2-ethylhexanoate (lithium, sodium, potassium) and anhydrous chromium (III) chloride in the absence of a solvent during mechanical activation using well-known devices used in mechanochemistry (ball, vibration ball, bead, planetary, shock, abrasive mills, disintegrants, mixtures Spruce-extruders), followed by heating the activated mixture.

The tasks are also solved by the described method of trimerization of ethylene in hexene-1 in a hydrocarbon solvent at a temperature of 40-95 ° C and a pressure of 1-5 MPa on a component of catalytic systems including tris (2-ethylhexanoate) chromium in combination with an organometallic cocatalyst, characterized in that the process of ethylene oligomerization is carried out in the presence of a component obtained by the method described in this application. The indicated ranges of temperature and pressure are selected to obtain the best values of the activity and selectivity of the catalytic systems. When the temperature drops below 40 ° C and the ethylene pressure in the reactor is below 1 MPa, such indicators as catalyst activity and selectivity of the ethylene oligomerization process sharply decrease. As the temperature rises above 95 ° C, the selectivity of the oligomerization reaction for the main product (hexene-1) decreases and the formation of undesired higher C ₈ -C ₁₄ olefins sharply increases. Carrying out the oligomerization process at a pressure of more than 5 MPa leads to a decrease in the selectivity of ethylene oligomerization over hexene-1 and an increase in the yield of by-products in the form of higher C ₈ -C ₁₄ olefins and a polymer.

Catalytic systems for ethylene oligomerization are a two-, three- or four-component system consisting of a chromium-containing component, an organoaluminum compound of the general formula AlR ₃ , where R is a C ₁ -C ₈ alkyl radical, a complexing agent of the type pyrrole or its derivatives, compounds, organic compounds containing nitrogen and phosphorus, etc., and a type modifier: AlR ₂ Cl, CCl ₄ , tetrahydrofuran, esters, amines. The catalytic activity (product g / g Cr. Hour) and the selectivity for the main product of the oligomerization reaction (% wt.) Strongly depends on the following factors: the nature of the solvent used and AlR ₃ , the type of complexing agent and modifier, the molar ratio of all components used specifically catalytic systems, ethylene pressure and temperature.

The invention consists in the following.

The preparation of the indicated component of the catalytic systems is carried out by reacting the starting solid reactants of 2-ethylhexanoate of a non-transition metal and anhydrous chromium (III) chloride at a ratio of reagents MC ₈ H ₁₅ O ₂ : CrCl ₃ > 1: 1 in the absence of a solvent during mechanical activation for a predetermined time using known devices, followed by heating the activated mixture before the start of an autothermal reaction. The mixture of non-transition metal salt and tris (2-ethylhexanoate) chromium obtained after heating can be directly used as a component of the catalytic system. Specifically, the mechanical activation of the solid reagents was carried out for 1-6 hours, preferably 4 hours at room temperature in a vibratory ball mill. The resulting finely divided powder of a bluish-pink color was then heated until the start of an autothermal reaction, in which the powder quickly turned into a sintered gray-green mass. When cooled to room temperature, the resulting composition turned into a solid, easily milled into powder. Subsequently, the obtained composition can be subjected to extraction with hexane to separate MCl from chromium carboxylate by filtering the resulting suspension.

On the degrams of the initial powders, there are CrCl ₃ reflections and carboxylic acid salts. Warming up the mixture of reagents without mechanical activation does not lead to an autothermal reaction and the formation of target products. After mechanical activation, reflexes that characterize the initial reagents remain on the de-grams, a wide band appears corresponding to the amorphized products of the mechanical activation of the reagents. After heating the mechanically activated mixture, the reflections of the starting materials disappear, a number of lines appear on the diffractograms corresponding to the presence of alkali metal chlorides LiCl, NaCl, or KCl, as well as a halo characterizing the presence of an amorphous phase. The data presented indicate the need for both mechanical processing and subsequent heating of activated mixtures.

A comparison of the IR spectra of the starting reagents, mechanically activated mixtures of the reagents and the isolated reaction products confirms the complete consumption of the starting reagents and the formation of chromium carboxylate in the mixture after heating the activated mixture.

The resulting reaction mixture and samples of Cr (EH) ₃ isolated by extraction from it were used as a component of ethylene trimerization catalyst systems. For comparison, we used the product of the company "abcr GmbH & Co. KG "(a solution in white alcohol, 8-10% Cr) obtained by long and multi-stage synthesis according to the method (Rb Steele, Fair Oaks, A. Katzakian, JJ Scigliano, EE Hamel. US Pat. 3838101, Sept.24.1974). Conditions: t = 40-95 ° C, P = 1-5 MPa, [Cr] = 4 · 10 ^-4 mol / l, Cr / 2,5-dimethylpyrrole / Al (C ₂ H ₅ ) ₃ / CCl ₄ = 1/3/15/2, the volume of the liquid phase is 55 ml. Oligomerization processes were carried out in a 200 ml stainless steel reactor. Before each experiment, the reactor was washed with heptane, sealed, heated to 90 ° C, evacuated for 40 min, and filled with ethylene (0.6 MPa). After that, the temperature of the reactor was brought to the required value and cyclohexane, a mixture of triethylaluminum / 2,5-dimethylpyrrole / carbon tetrachloride in cyclohexane and a solution of the resulting composition or Cr (EH) ₃ isolated in cyclohexane were charged with metal syringes. Then ethylene was fed into the system until the required pressure was reached. The progress of the reaction was monitored by the pressure drop in the measuring cylinder from which ethylene was introduced into the reactor to maintain a constant pressure in it. After a certain time, isopropanol was loaded into the system, the stirring was turned off and the reactor was cooled to 7-10 ° C. Then, ethylene from the reactor was discharged into the atmosphere and a sample of the liquid phase was taken to perform gas chromatographic analysis. The products of the ethylene oligomerization reaction were analyzed on a Chrom 5 gas chromatograph equipped with a capillary column (TR-5 MS from Thermo Fisher Scientific, 30 m long, 0.25 mm inner diameter, stationary phase thickness 0.25 μm) and flame -ionization detector using helium as a carrier.

The claimed technical solution has a number of significant differences from the prototype:

- the starting reagents are introduced into the reaction in the form of solids;

- the reaction is carried out not in solution, but in the solid phase in the absence of solvent;

- the reaction is carried out by mechanical activation of a mixture of solid reagents;

- a mechanically activated mixture of solid reagents is subjected to heat treatment.

The composition formed as a result of these operations (a mixture of chromium carboxylate with group 1 metal chloride) can be directly used as a component of a highly efficient ethylene trimerization catalytic system. All these differences indicate that the proposed technical solution meets the criterion of "novelty."

The proposed technical solution can significantly reduce the duration of the process of obtaining a catalytically active composition (from 24-96 hours to 2-4 hours); to exclude the use of a fire hazardous organic solvent (tetrahydrofuran) at the synthesis stage; to exclude the stages of isolation of the target product and its purification from excess of ethyl hexanoate of metal of group 1, significantly increase the catalytic activity of ethylene oligomerization systems. These features of the developed technical solution indicate that it meets the criterion of "positive effect".

The invention is supported and illustrated (but not limited to) by the following examples.

Example 1

A mixture of 0.105 g (0.66 mmol) of CrCl ₃ and 0.386 g (2.30 mmol) of sodium 2-ethylhexanoate NaC ₈ H ₁₅ O ₂ was subjected to mechanical treatment for 1.5 h in a vibration ball mill. The obtained fine powder of dark pink color was heated before the start of the autothermal reaction. The powder quickly turned into a sintered gray-green mass. The resulting reaction mixture was used as a component of the [Cr] / Al (C ₂ H ₅ ) ₃ / 2,5-dimethylpyrrole / CCl ₄ (mol.) Oligomerization of ethylene in hexene-1 catalyst system (hereinafter, unless otherwise indicated, [Cr] - chromium-containing component, ethylene pressure 2 MPa, temperature 60 ° С). The activity of the catalytic system was 11,600 g of product / (g _Cr · h) with a content of 84.3% C ₆ in the product. See table 1, example 1.

0.39 g of the heated reaction mixture was used to isolate the product by hexane extraction. The green hexane solution was filtered to separate NaCl. After distilling off the solvent and drying in vacuo (160-170 ° C), a greenish dark-colored powder was obtained. Yield 0.168 g (conversion to tris (2-ethylhexanoate) chromium - 66% based on CrCl ₃ ). Found,%: C 59.94; H 9.71; Cr 11.3. C1 0.9. For Cr (C ₈ H ₁₅ O ₂ ) ₃ calculated,%: C 59.85; H, 9.42; Cr 10.8.

Example 2

The preparation of the component of the catalytic systems was carried out analogously to example 1, with the difference that 0.24 g (1.51 mmol) of CrCl ₃ and 0.88 g (5.29 mmol) of NaC ₈ H ₁₅ O ₂ were introduced into the reaction and the mixture was subjected to mechanical treatment for 2 hours. the mixture was used as a component of a catalytic system for ethylene oligomerization in hexene-1. The activity of the catalytic system is 12000 g of product / (g _Cr · h) with a content of 86.9%) C ₆ in the product. See table 1, example 2.

Example 3

The preparation of the component of the catalytic systems was carried out analogously to example 1, with the difference that 0.27 g (1.7 mmol) of CrCl ₃ and 0.99 g (5.95 mmol) of sodium 2-ethylhexanoate NaC ₈ H ₁₅ O ₂ were introduced into the reaction and the mixture was subjected to mechanical treatment for 3 h. The resulting reaction mixture was used as a component of the catalytic system for the oligomerization of ethylene in hexene-1. The activity of the catalytic system is 13500 g of product / (g _Cr · h) at a content of 95.0% C ₆ in the product (selectivity for hexene-1> 99.9%). See table 1, example 3.

Example 4

The preparation of the component of the catalytic systems was carried out analogously to example 1, with the difference that 0.125 g (0.79 mmol) of CrCl ₃ and 0.460 g (2.77 mmol) of sodium 2-ethylhexanoate NaC ₈ H ₁₅ O ₂ were introduced into the reaction and the mixture was subjected to mechanical treatment for 4 h. The resulting composition was used as a component of the catalytic system of oligomerization of ethylene in hexene-1. The activity of the catalytic system is 11500 g of product / (g _Cr · h) with a content of 94.6% C ₆ in the product (selectivity for hexene-1 99.9%). See table 1, example 4.

After extraction of 0.455 g of the reaction mixture, 0.270 g of product was obtained (degree of conversion of CrCl ₃ ~ 93%).

Examples 1-4 show that when the reagent ratio is close to stoichiometric, an increase in the activation time from 1 to 4 hours leads to an increase in the degree of conversion of the reagents to Cr (EN) ₃ to a value close to quantitative conversion. Thus, a further increase in the duration of the process in the conditions used is impractical.

Example 5

0.3 g of the heated reaction mixture obtained in example 2 was used to isolate the product by hexane extraction. The green hexane solution was filtered to separate NaCl. After distilling off the solvent and drying in vacuo (160-170 ° C), a greenish dark-colored powder was obtained. Yield 0.22 g (degree of conversion of Cr (ЕН) ₃ - 74% calculated on CrCl ₃ ).

The resulting Cr (EH) _{3 was} used as a component of the Cr (EH) ₃ / A1 (C ₂ H ₅ ) ₃ / 2,5-dimethylpyrrole / CCl ₄ catalyst system of oligomerization of ethylene in hexene-1.

The activity of the catalytic system is 49600 g of product / (g _Cr · h) with a content of 95.8% C ₆ in the product (selectivity for hexene-1> 99.9%). See table 1, example 5.

Example 6

The reaction mixture obtained in example 3 was used as a component of the catalytic system for ethylene oligomerization in hexene-1, similarly to examples 1-4, but at a concentration of Cr = 2.6 · 10 ^-4 mol / L. The activity of the catalytic system is 92,200 g of product / (g _Cr · h) with a selectivity of 95.6% C ₆ in the product (selectivity for hexene-1> 99.9%). See table 1, example 6.

Example 7

The reaction mixture obtained in Example 3 was extracted with hexane in the same manner as in Example 5. After extraction, 0.86 g of the reaction mixture yielded 0.45 g of product (conversion of CrCl ₃ to Cr (ЕН) ₃ ~ 82%) and was used as a component of the catalyst system Cr (ЕН) ₃ / Al (C ₂ H ₅ ) ₃ / 2,5-dimethylpyrrole / CCl ₄ oligomerization of ethylene in hexene-1. The activity of the catalytic system is 46,400 g of product / (g _Cr · h) with a content of 98.5% C ₆ in the product (selectivity for hexene-1> 99.9%). See table 1, example 7.

Example 8

The preparation of the component of the catalytic systems was carried out analogously to example 1, with the difference that 0.045 g (0.28 mmol) of CrCl ₃ and 0.149 g (0.99 mmol) of LiC ₈ H ₁₅ O ₂ were introduced into the reaction, and the mixture was subjected to mechanical treatment for 3 hours. the mixture was used as a component of a catalytic system for ethylene oligomerization in hexene-1. The activity of the catalytic system of 7500 g of product / (g _Cr · h) at a content of 98% C ₆ in the product. See table 1, example 8.

Example 9

ABCR GmbH & KG Cr (EN) ₃ (commercial reagent) was used as a component of the Cr (EH) ₃ / Al (C ₂ H ₅ ) ₃ / DMP (2,5-dimethylpyrrole) / CCl ₄ catalytic system for the oligomerization of ethylene in hexene-1 . The activity of the catalytic system of 8200 g of product / (g _Cr · h) with a content of 86% C ₆ in the product (selectivity for hexene-1 97%). See table 1, example 9.

Example 10

The preparation of the component of the catalytic systems was carried out analogously to example 1, with the difference that 0.075 g (0.47 mmol) of CrCl ₃ and 0.18 g (1.08 mmol) of sodium 2-ethylhexanoate NaC ₈ H ₁₅ O ₂ were introduced into the reaction and the mixture was subjected to mechanical treatment for 3 h. After heating the reaction mixture, a viscous dark green mass formed, the IR spectrum of which is significantly different from the spectrum of the target product. After extraction, a significant amount of chlorine was detected in the isolated product. This example shows that at least a stoichiometric ratio of reagents is required to completely remove chlorine and produce Cr (EH) ₃ .

The resulting reaction mixture was used as a component of the catalytic system for ethylene oligomerization in hexene-1. The activity of the catalytic system 6800 g of product / (g _Cr · h) with a content of 87.8% C ₆ in the product. See table 1, example 10.

Example 11

The preparation of the catalyst system component was carried out analogously to example 1, with the difference that 0.045 g (0.28 mmol) of CrCl ₃ and 0.195 g (1.1 mmol) of sodium 2-ethylhexanoate NaC ₈ H ₁₅ O ₂ were introduced into the reaction and the mixture was subjected to mechanical treatment for 3 h. After extraction of 0.20 g of the reaction mixture, 0.105 g of product was obtained (CrCl ₃ conversion ratio ~ 96%). This example shows that a small excess of NaC ₈ H ₁₅ O ₂ leads to an increase in the degree of conversion of CrCl ₃ to almost quantitative and a further increase in the excess is impractical in order to save reagents.

The resulting reaction mixture was used as a component of the catalytic system for ethylene oligomerization in hexene-1. The activity of the catalytic system is 12500 g of product / (g _Cr · h) with a content of 84.4% C ₆ in the product. See table 1, example 11.

Example 12

The preparation of the component of the catalytic systems was carried out analogously to Example 1, with the difference that 0.055 g (0.34 mmol) of CrCl ₃ and 0.220 g (1.2 mmol) of KC ₈ H ₁₅ O ₂ were introduced into the reaction and the mixture was subjected to mechanical treatment for 3 h.

The resulting reaction mixture was used as a component of the catalytic system for ethylene oligomerization in hexene-1. The activity of the catalytic system 5600 g of product / (g _Cr · h) with a content of 89% C ₆ in the product. See table 1, example 12.

Example 13

The reaction mixture obtained in Example 3 was used as a component of the catalytic system for the oligomerization of ethylene in hexene-1 at a temperature of 95 ° C.

The activity of the catalytic system 85300 g of product / (g _Cr · h) with a content of 96.0% C ₆ in the product (selectivity for hexene-1> 99.9%). See table 1, example 13.

Example 14

The reaction mixture obtained in example 3 was used as a component of the catalytic system for the oligomerization of ethylene in hexene-1 under the conditions of example 6, but at a temperature of 40 ° C. The activity of the catalytic system 62100 g of product / (g _Cr · h) with a content of 94% C ₆ in the product (selectivity for hexene-1> 98%). See table 1, example 14.

Example 15

The reaction mixture obtained in example 3 was used as a component of the catalytic system for the oligomerization of ethylene in hexene-1 under the conditions of example 6, but at a pressure of 1 MPa. The activity of the catalytic system was 66200 g of product / (g _Cr · h) at a content of 95% C ₆ in the product (selectivity for hexene-1> 99.9%). See table 1, example 15.

Example 16

The reaction mixture obtained in example 3 was used as a component of the catalytic system for the oligomerization of ethylene in hexene-1 under the conditions of example 6, but at a pressure of 5 MPa. The activity of the catalytic system 122400 g of product / (g _Cr · h) with a content of 93.5% C ₆ in the product (selectivity for hexene-1 97.2%). See table 1, example 16.

Comparison of our results (examples 1-16) with published data [1) Khasbiullin I.I. Dis. Ph.D. Kazan. 2013. S. 114, S. 130; 2) patent RU 2412002 C1; 3) Yang Y. et al. Appl. Catal. A. 2000. V. 193. No. 1-2. P. 33; 4) Fang Y. et al. Appl. Catal. A. 2002. V. 235. No. 1-2. P. 35] shows that the use of a catalyst component of the ethylene oligomerization catalyst system obtained by the proposed method without the use of additional purification or the use of physical methods of stimulating reactions allows a significant (several-fold) increase in the activity of the catalyst and a decrease in the proportion of polymer formed compared to similar catalytic systems for ethylene oligomerization based on a commercial product or based on a product obtained from reactions using sol Itel (Wed examples 1-7 and 9, paragraphs 17-20, Table 1).

Thus, the described method for producing a component of the catalytic system and the method of oligomerization of ethylene allow:

- in one step, without additional purification, to obtain a chromium component of catalytic systems of ethylene oligomerization, which provides a significantly higher activity of catalytic systems compared to catalytic systems that use Cr (ЕН) ₃ obtained by reactions using solvents;

- significantly reduce the duration of the process of obtaining a component of catalytic systems (from 24-96 hours to 2-4 hours);

- to exclude the use at the stage of synthesis of the component of the catalytic systems of any solvents, including those used in the prototype fire hazardous organic solvent (tetrahydrofuran);

- to exclude the stage of separation of the target product and its purification from excess of ethyl hexanoate of metal of group 1, excess of 2-ethylhexanoic acid;

- to exclude the formation of products of hydration, hydrolysis and polycondensation of the chromium-containing component, leading to a decrease in catalytic activity and selectivity of the process and thereby eliminate the need to purify the chromium-containing component from these products;

- to store the catalyst for a long time in a compact form without loss of its activity and selectivity.

Analysis of the existing scientific, technical and patent literature showed that the claimed combination of features meets the criterion of industrial applicability, and also confirms the compliance of the claimed invention with the criteria of novelty and significant differences.

Table 1 Reaction conditions for ethylene oligomerization catalytic system Cr (EH) ₃ / DMP / AlEt ₃ / CCl ₄ = 1/3/15/2 (mol). A - activity of the catalytic system, P - polymer Example No. Chromium component [Cr] · 10 ⁴ , mol / L Time min T, ° C P, MPa A, g / (g _Cr · h) C ₄ ,% of the mass. C ₆ ,% of the mass. C _n ,% wt. The polymer,% of the mass. one Received according to example 1 4.0 60 60 2 11600 0.3 84.3 (97.5) 15.1 0.3 2 Obtained in example 2 4.0 60 60 2 12000 0.3 86.9 (98.0) 12.6 0.2 3 Obtained according to example 3 4.0 60 60 2 13500 0.1 95.0 (> 99.9) 4.0 0.1 four Obtained according to example 4 4.0 60 60 2 11500 0.1 94.6 (99.0) 5.2 0.1 5 Cr (EH) ₃ , isolated from the reaction mixture, pr.2 4.0 40 60 2 49600 0 95.8 (> 99.9) 4.1 0.1 6 Obtained according to example 3 2.6 40 60 2 92200 0 95.6 (> 99.9) 4.4 0.1 6 Obtained according to example 3 2.0 60 60 2 12900 0.2 85.8 (97.8) 13.9 0.1 7 Cr (EH) ₃ isolated from reaction mixture pr 3 4.0 40 60 2 46400 0 98.5 (> 99.9) 1.4 0.1 8 Obtained according to example 8 3,1 fifty 60 2 7500 0.1 98.0 (98) 1.7 0.2 9 prototype Cr (EH) ₃ ABCR GumbH & Co.KG 4.0 60 60 2 8200 0.3 86.0 (97.0) 13.3 0.4 10 Obtained in example 10 4.0 60 60 2 6800 0.3 87.8 (97.8) 11.8 0.1 eleven Obtained according to example 11 4.0 60 60 2 12500 0.2 84.4 (97.3) 15,2 0.2 12 Obtained according to example 12 2,5 40 60 2 5600 0.5 89.0 (98.0) 10,2 0.3 13 Obtained according to example 13 2.6 40 95 2 85300 0 96.0 (> 99.9) 4.0 0.1 fourteen Obtained according to example 14 2.6 40 40 2 62100 0 94.0 (98.0) 5.7 0.3 fifteen Obtained according to example 15 2.6 40 60 one 66200 0.1 95.0 (> 99.9) 4.8 0.1 16 Received according to example 16 2.6 40 60 5 122400 0 93.2 (97.2) 6.5 0.3

Claims (4)

1. The method of obtaining a component of the catalytic system for the oligomerization of ethylene by reacting 2-ethylhexanoates of metals of group 1, mainly lithium, sodium, potassium, and chromium (III) chloride, characterized in that the interaction is carried out by mechanical activation of the solid mixture at a ratio of reagents 2-ethylhexanoate Group 1 metal: CrCl ₃ > 1: 1, respectively, and heating the activated mixture to obtain the desired product. 2. A component of the catalytic system for ethylene oligomerization, which is a product of the interaction of 2-ethylhexanoates of Group 1 metals, mainly lithium, sodium, potassium, and chromium (III) chloride, obtained by the method described in paragraph 1. 3. A catalytic system for the oligomerization of ethylene containing an organoaluminum compound of the general formula AlR ₃ , a complexing agent, a modifier, a solvent and a chromium-containing component, characterized in that the component according to claim 2 is used as the chromium-containing component. 4. The method of oligomerization of ethylene in a hydrocarbon solvent at a temperature of 40-95 ° C and an ethylene pressure of 1-5 MPa in the presence of AlR ₃ , a complexing agent and a modifier, characterized in that the ethylene oligomerization process is carried out in the presence of a catalytic system according to claim 3.