SU318217A1 - METHOD OF OBTAINING OLEFINS - Google Patents

Description

The invention relates to a process for the production of olefins by dimerization and codimerization in the liquid phase of lower C2-Q olefins, especially dimerization of propylene in order to obtain a product with a very high content of methyl pentenes.

A known method for producing C4-Sb olefins by dimerization and codimerization of ethylene and propylene at pressures in the range from normal to 25 atm and temperatures from -50 to + 150 ° C in an organic solvent medium and in the presence of a catalytic system consisting of triphenylphosphine and two metal-containing compounds, one of which is the general formula RzMXy, where R is a hydrocarbon radical;

M - aluminum, gallium, indium, chromium, beryllium, titanium, vanadium; X is halogen;

Z is an integer varying from zero to / g - the valence of M;

Y is an integer equal to (p-z) and the other is of the general formula RpMe, where R is the residue of an organic acid, an allyl or cyclonentadienyl group or halogen; Me - nickel, cobalt, iron; p is an integer equal to valency. Me.

However, the use of α-allyl complex compounds of nickel halide with triphenylphosphine and dichloroethyl aluminum, which are difficult to prepare, is very sensitive.

are suitable for oxygen in the air and require sufficiently low working temperatures for a period of time; from -10 to -20 ° C, does not provide a high product yield and high selectivity of the process.

In order to eliminate these drawbacks, it is proposed to use a compound of the general formula as a metal-containing component

Ni (R2SO) 6 MX4

where R-Ci-Cz alkyl, preferably methyl or ethyl, aryl, preferably phenyl or two R together can form a methylene closed chain, for example, tetramethyl is new, i.e. RaSO can take the form

sn

CH.

CH3-S-CH3; C2H5-S-C3H3; CH2-S-CH .;

25

M - iron, nickel or cobalt or any transition metal of group VIII; X is halogen, in particular chlorine, bromine or iodine.

The catalyst is usually reacted in an amount of 0.005-5 g per 1 / cr olefin in terms of metallic nickel as a transition metal.

In order to accelerate the activation of the catalyst and, consequently, increase the reaction rate, O-2 mol of water per 1 mol of the nickel complex compound is added to the reaction mixture.

As the amount of water increases, the degree of selectivity of the process decreases.

Nickel sulfoxide complex compounds are readily prepared by known methods. Organic compounds of aluminum are commonly used as RA1X2 and .RsAlsXs, where R is alkyl, for example ethyl, propyl, isopropyl, butyl or isobutyl, X is chlorine and / or bromine.

The ratio between the organoaluminum component and the nickel complex compound is 3-100. It is desirable that the atomic ratio aluminum: transition metal in the catalytic system is 6–12, preferably 7–9, when the catalyst is prepared on site, i.e. when the sulfoxide complex compound of nickel and the transition metal, the solvent, organoaluminum compound and olefin.

On the contrary, this ratio should be greater, preferably should be 15-50 and better than 20-30 when the catalyst is prepared in advance, i.e. before it is brought into contact with dimerizuyushim olefin. Within these limits, the selectivity itself is high.

. In preparing the catalyst in the reaction medium, the amount of the latter may be such that the weight of the transition metal of the complex compound used is 0.05-5 g (in the case of nickel) per 1 kg of olefin. Good results are obtained with a nickel content of 0.1-1 g nickel per 1 kg of olefin. If the catalyst is prepared in advance, the amount of nickel is 0.005-1 g. Good results are obtained with a nickel content of 0.001-0.5 g.

Dimerization is carried out at a temperature of from -50 to 4-80 ° C, but the best results are obtained at a temperature of (-5) - (+10) ° C. Conversion is almost 100% observed at 0 ° C.

Solvents suitable for dimerisadia are inert liquids to the catalyst, in particular, powdered hydrocarbons, sometimes halogenated, aromatic or haloaromatic hydrocarbons; aliphatic, aromatic or cyclic ethers, not reactive, not with a catalyst.

matic solvents. Liquid propylene can also serve as a solvent, as dimers obtained in the reaction. It is recommended to choose a solvent with a rather high boiling point and a sufficiently low solidification point in order to easily release the formed dimers without danger of solidification at low temperatures.

Example I. 30.6 g of liquid propylene are dimerized in the presence of a catalyst consisting of 0.35-10-3 mol of the Ni ((CH2) 45Ob) NiCU complex and 2.5-10 mol of ethyl aluminum chloride and 10 ml of a- Chlornaphthalene. After 225 minutes, 28.5 g (93%) of liquid oligomers are obtained, of which 25.6 g of dimers are separated. 90% dimer selectivity. The resulting dimer consists (in%) of 69.5 methyl pentenes, 27.1 hexenes, and 3.4 dimethyl butenes. The content of methyl-2-pentene-2 in this mixture is 46.3%.

Example 2. For dimerization, a catalyst was used consisting of Ni ((CH3) 25 O) b NiCU and (CH3 CH2) H-Al2 Ni (Al / Ni 7), taken in the same amounts as in Example 1.

The solvent is 10 ml of α-chloronaphthalene. From 30 g of liquid propylene, after 133 minutes at 0 ° C, 28.6 g (conversion of 95.5%) of liquid oligomers are obtained, of which 27.4 g (96% selectivity) are dimers containing (in%); 71.4 methyl pentenes, 25 hexenes, 3.6 dimethyl butenes. The amount of methyl-2-pentene-2 is 55.1%. 18.75 kg / h of oligomers are obtained per 1 g of nickel.

Example 3. The experiment was carried out as in example 2, at different temperatures. The results obtained are carried out below.

Temperature, ° С Reaction time,

min

Conversion,% Selectivity,

Example 4. In the experiment, as in example 2, using a complex, the anion of which is ReSC, and the cation Ni (CbH5), the conversion of propylene is 95%, the selectivity is 94%.

Example 5. Analogously to Example 2, when using a catalyst in a dose of 1 g of nickel per 1 kg of propylene, a change in the Al / Ni atomic ratio leads to the following results (see Table 1).

Table 1

The data show that the very high selectivity is obtained when the ratio Al / Ni is close to 7. At a lower value of this magnitude, the reaction time is much longer.

Examples b-11. To assess the effect of water present in the catalyst, the experiment was carried out as in Example 2, but 90 g of propylene was used to increase the accuracy of the experiment. The results are presented in table. 2

table 2

ten

15

 The dimer contains (in%): 72 methylpenthenes, 25 geyseiov and 3 dnmetilbutenov. The Dniers, described in the other examples, have a bold composition.

From the data given in table. 2, it follows that the addition of water shortens the reaction time, without causing a decrease in selectivity, if its content does not exceed 2 mol pas 1 mol of the nickel complex.

Examples 12-17. Dimerization.

A stainless steel autoclave with a capacity of 250 ml, cooled to 0 ° C with a thermostatic fluid circulating through a double jacket, was injected in an argon atmosphere 40 ml of a catalytic solution containing 3.23 mg of nickel. 30.6 g of propylene are introduced while maintaining the temperature at 0 ° C. Initial pressure 5 bar. Lowering the pressure allows monitoring the progress of the reaction. When the pressure drops to zero, the reaction is complete. 10 ml of water was added to deactivate the catalyst.

The organic phase is isolated and distilled. Conversions in all subsequent examples 100%. The reaction rate or productivity is calculated as the amount of propylene reacted per I g Ni over 1 hour.

The results are summarized in table. 3

The data show that with an increase in the Al / Ni ratio, the reaction time decreases, but the selectivity decreases.

Examples 18-22. Wire dimerization, as in Examples 12-17, removes the effect of small amounts of water in the catalyst.

Call for selectivity if the overall water / aluminum ratio does not exceed 0.3.

For Example 22, the rate of conversion of propylene is calculated, starting from 95 kg of propylene / g Ni-hour at 0 ° C.

Example 23. When using 20 ml of a catalytic solution (Al / Ni 50), 30.6 g of propylene at 15 ° C is completely converted to a dimer in 5 minutes. The conversion rate of propylene is 228 kg / h-hr.

Example 24. Dimerization 30.6 g of propnylene at 0 ° C is added in 2 minutes.

using 40 ml of a catalytic thief (Al / Ni 28). Conversion speed

283 kg1g-hour is propylene.

Selectivity -, „..

Thus, the use of (SNSNz)

AlCb instead of ethyl aluminum pentochloride | does not result in more active pah

cross sections, but selectivity is reduced.

To achieve the same results, it is necessary to increase the ratio Al / Ni npiji, all other things being equal.

Example 25-29. Using a catalytic solution, in which the Al / Ni ratio changes, at -10 ° C, 30.6 g of propylene is dimerised (see Table 5),

Table 5

 The amount of catalytic solution 30 ml. The amount of catalytic analysis is 20 ml.

Lriemer 30. A stainless steel autoclave cooled to 0 ° C is injected in an inert atmosphere with 80 ml of a catalytic solution (Al / Ni 25) containing 6.4 mg of nickel. At a pressure of 1 bar, ethylene is introduced. After 20 min, 42 ml of l of similar olefins of the following composition (in%) are separated:

S461

Sat36

GS and above 3

Example 31. After replacing ethylene with 1-butene and driving the process as in Example 30, after 6 hours, the organic phase consisting of octenes is separated and distilled.

Example 32. In a 500 ml stainless steel autoclave at 25 ° C, 75 ml of butenes are condensed, 200 ml of a catalytic solution (Al / Ni 25) is added. The autoclave is cooled to 0 ° C and propylene is introduced at atmospheric pressure. After 1 hour, volatiles are removed, 51 g of liquid feedstock are separated, which contain 37.5 g of olefins in composition (%):

Sat30.55

St46,5

Cg23

Subject invention

Claims (3)

1. A method of producing olefins by dimerization and sodimerization of C2-C4 olefins in an organic solvent at a temperature of (-50) - (+80) ° C in the presence of a catalytic system consisting of two metal-containing compounds, one of which is an organoaluminum compound containing halogen , characterized in that, in order to increase the yield of the target product and the selectivity of the process, as another component of the catalytic system, a complex compound of the general formula is used NKR2SO) 6 MX4 where R is Ci-C3 alkyl, aryl or two R together form a methylene closed chain; M - any transition metal VIII groups, X - halogen. 2. A method according to claim 1, characterized in that the catalyst is introduced into the reaction in an amount of 0.005-5 g per 1 kg of olefin, calculated on metallic nickel, as a transition metal. 3. The method according to claim 1, characterized in that water in an amount of up to 2 mol per 1 mol of the complex compound is added to the reaction mixture.