SU981307A1 - Process for producing butenes - Google Patents

Description

(54) METHOD FOR OBTAINING BUTENES

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This invention relates to petrochemical synthesis, in particular to methods for producing butenes by dimerizing ethylene. Butenes are valuable raw materials for the production of rubbers, as well as alkyl aromatic compounds.

The known method of producing butenes by oligomerization of ethylene at t ' -80 and pressures up to 100 atm in the presence of a homogeneous solution in l SCCd (or aromatic hydrocarbons) of Pg.-allyl nickel complexes, including PG-all-nickel halides and activators-AB-organic compounds at a ratio of C l: 2-l: 5O l

The performance of this method does not exceed 40 kg / g Ni h, and the selectivity of dimers is 60-7O%. The main disadvantages of the method for producing buds are: low selectivity of the process 20 for the desired product due to the formation of significant amounts of high oligomers; the complexity of the synthesis of a meta-complex catalyst resulting in

typically, with low yields, and catalyst instability — in air (immediate and irreversible decomposition of the active phase — TG-allyl nickel halide complex); small times (significantly less than an hour) of the operation of homogeneous catalysts and their one-time use only.

The closest to the invention is the method of producing monoolefinic hydrocarbons in the number of butenes by dimerizing the corresponding mono-olecules in the presence of a catalytic system, containing

 The catalyst is complex nickel compounds, such as dicarbonylditripheniphosphine nickel, and as an activator, an organoaluminium compound, for example () P,, where. The process can be carried out at 15Os and pressures up to 10O atm. in the medium of an organic solvent, for example, chlorobenzene, benzene, heptane, etc. So, when dimerization of ethylene in the presence of a cut catalyst and At -t, taken in a molar ratio of 1:20 rp and a pressure of 1 atm, the selectivity for the buta is 75.6% 2. The disadvantage of the method is the non-selectivity for the target product butenes due to the formation of three-. mer and higher ethylene oligomers. The aim of the invention is to increase the selectivity of the process for the desired product. This goal is achieved by the method of producing butenes by dimerizing ethylene at elevated pressure in the presence of a catalyst — dicarbonylditriphenylphosphine-nickel on an alumina carrier at a weight ratio of carrier: k; atalizator- (3.6-50): and catalyst — organoaluminum compound () y, ,, where., in the environment of hydrocarbon aromatic or aliphatic solvent. Preferably, the process is carried out at a molar ratio of catalyst; activator {8-736): 1, at a temperature of 20-8 ° C and pressures of 2-2O atm; Gensane, heptane, benzene, and tolu can be used as solvents. P pam p 1. Preparation of the catalyst. 5 g of industrial (190-200 m specific surface) are fed into a quartz reactor, connected to a vacuum unit, heated for 6 hours at 450P С and cooled to О С under pressure Р 10t, treated with triphenylphosphine solution () in benzene without air access at at room temperature, 1 hour, benzene was removed by vacuum. Into the reactor with the carrier, OB15O, 085.10 OD 8 98.041.96

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Table 1

61: 1 5: 1 4.4: 1 25: 1 Tested PPL, Wi pairs supplied (about TOJDp, kept 30-40 minutes, excess Mi (CO) removed, reducing pressure to 2:10 tbp, samples of Hi analyzers are obtained (PP ;,) (CO). Table 1 shows the characteristics of samples of catalysts obtained in Reamer 1. Example 2. To a 1 m reactor under nitrogen atmosphere are introduced 34 O of a dry hexane fraction of gasoline, 50 g of catalyst (sample no. 3, Table 1) creates an ethylene pressure of 2 atm and a solution of (CdH) AC, C in hexane is introduced. After 1.5–20 min, intensive absorption of ethylene begins. The pressure in the reactor is adjusted so that temperature would not exceed 60-65 C (atm). The process is stopped after 4 hours. Table 2 shows the conditions and results of experiments on the dimerization of ethylene in 1 and i (,,) (CO) (reactor 0.5 l; 200 ml of solvent; activator (s). Examples No. 3-11. In a 0.5 liter metal reactor in a nitrogen atmosphere, the solvent is loaded, the catalyst prepared according to Example 1 is introduced, nitrogen is removed, the working pressure of ethylene is created, A is an organic compound and the test is carried out at a constant selected pressure. In tab. 3 shows the composition of ethylene dimerization products in the presence of Mi (PPIl3) a (C0) / Ae2. Oz The proposed method has high performance (30-3490 g / g. Mi h) and high selectivity of the process for the target product (85-96% of butenes).

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Claims (2)

о 9 9.813 Claim 1. The method of producing butenes by dimerization of ethylene with increased pressure in the presence of a catalyst dicarbonylditriphenylphosphine nickel and 5 activator - organoaluminum compound () AE-CEz-I, in an aromatic hydrocarbon or aliphatic solvent environment, characterized in that. In order to increase the selectivity of the procedure for the target product, a supported catalyst is used, alumina with a weight ratio of 10 10 carrier: catalyst equal to (3.650): 1. 2. Pop method. X. removal and with the fact that the process is carried out at a molar ratio of catalyst:: activator (8-7 36):., At a temperature of 20-80 ° C and a pressure of 2-2O atm. Sources of information taken into account in the examination of e 1. The patent of Germany Ms 1520964, №. C 07 C 3/21, 1975. 2. Patent of the USSR No. 334675, cl. C 07 C 2/32, 1972, (prototype).