FI90231C - Method for oligomerization of 1-butene - Google Patents

Description

90231

The present invention relates to a process for the oligomerization of 1-butene. The present invention relates to a process for the oligomerization of 1-butene.

PRIOR ART

Traditionally, iso- or tert-butene has been used as butene in the preparation of butene oligomers, which has been oligomerized to an oligomer of suitable molecular weight. These oligo- and polymers formed in the oligomerization of iso-butene are collectively referred to as poly-i-butenes or polybutylenes, depending on the composition of the starting material.

The source of i-Butene has mainly been the so-called raffinate I stream. In this stream, raffinate I 15 contains, in addition to iso-butene, 1- and 2-butenes as well as butanes. Alternatively, purified iso-butene has been used as a starting material.

The most important mechanisms for polymerizing olefins are the cationic mechanism and coordination polymerization. These coordination polymerizations are mainly used for the production of poly-1-20 butene plastics, where it is desired to determine very precisely the structure of the resulting product. In the polymerization of 1-butene, the cationic mechanism produces only oligomers or viscous liquids, the so-called nestepolymeerejå.

Lewis acids such as BF3, AlCl3, AlBr3, TiCl4, SnCl4, etc. have been used as catalysts in the cationic mechanism. It is known that Lewis acid catalysts alone cannot initiate the polymerization reaction, but require a proton donor, i.e. a cocatalyst. Such cocatalysts include e.g. water, alcohols, carboxylic acids, inorganic acids, certain alkyl halides or halogens. The oligomerization can be carried out in bulk, i.e. without a co-solvent, or in the presence of an inert solvent. Such inert solvents include e.g. alkanes such as hexane and heptane, and cycloalkanes such as cyclohexane and cycloheptane.

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Thus, oligomers suitable for a variety of applications have traditionally been prepared by oligomerization of an iso-butene or raffinate I stream. The catalyst used is e.g. BF3 and AlCl3. The cocatalyst is usually said water, lower alcohols and organic acids. A 1-butanol cocatalyst has been commonly used with BF3 for the purpose of producing fractions suitable as lubricants and additives. These fractions have been produced mainly by copolymerization. Larkin et al. (US 4,417,082, 4,395,578 and 4,434,309) use 1-butene as a short-chain olefin and a C6-C18-alkene as a long-chain olefin in the copolymerization. The catalyst system consisted of BF3 and 1-butanol as well as a possible transition metal cation. Nipe et al. (US 4,225,739) also used 10 BF3-1-butanol catalysts for the copolymerization, but the short-chain olefin was propylene instead of 1-butene. Watts et al. (US 4,413,156) used a mixture of C3-C4 olefins as a starting material, from which C9 to C24 olefins were prepared by a disproportionation reaction. Further oligomerization of this fraction with a BF3-1-butanol catalyst gave fractions suitable for the preparation of lubricant additives. The processes described in the aforementioned patents are either two-step or copolymerizations.

The catalysts used to oligomerize the raffinate I stream depend in part on the desired product distribution. Torck et al. (GB 1 312 950) used as di- and trimerization catalysts e.g. BF3-HF complex in tetramethylenesulfonic solution. Chen et al. (US 4,849,572) used anhydrous and / or methanol as cocatalyst, the product being Mn = 520 to 1500 g / mol. For the oligomerization of a raffinate II stream containing 1- and 2-butenes as main components, Halaska et al. (EP 337 737) use BF3 or alkylaluminum chlorides of the general formula R2A1Cl or RA1C12, where R is C1-6 alkyl. As cocatalysts, they use HF, HCl or compounds having a reactive chlorine or fluorine atom attached to a tertiary, benzylic or allylic carbon atom. These catalyst systems are the same as those described by Loveless et al. (US 4,041,098) Catalysts used for the oligomerization of C3 to C14 olefins, preferably C8 to C10 olefins.

Carboxylic acid cocatalysts are little known in the oligomerization of short chain olefins. Sheng et al. (US 4,263,465) use a carboxylic acid having up to five carbon atoms as cocatalyst. Their process was two-step. The first 3,90231 step involved the oligomerization of 1-butene into a fraction having a number average carbon chain length of 8 to 18, preferably 10 to 16 carbon atoms. In the second step, the product fraction of the first step is co-oligomerized with a C8 to C18 alpha-olefin. Carboxylic acids, • e.g. containing five carbon atoms has been used for the oligomerization of longer chain olefins. For example, according to GB 1 378 449, n- and i-Valeric acid, methylbutanoic acid or mixtures thereof have been used to catalyze the oligomerization of C6 to C12 olefins together with BF3.

The production of MTBE 10, i.e. methyl tert-butyl ether, which has grown strongly and continues to grow over the last ten years, limits the availability of iso-butene (while raising production costs). The object of the present invention is to show that by oligomerizing 1-butene to poly-n-butene, it is possible to produce fractions replacing light oligomers of iso-butene (Mn = ΙΙΟ.,. Η. 650 g / mol or even 850 g / mol). Poly-i-butene and polybutylene have been produced for several years even on an industrial scale, but the production of poly-15 n-butene by oligomerization of 1-butene is not known.

In the present invention, the oligomerization of 1-butene is carried out in a one-step process using a boron trifluoride-cocatalyst complex in which the cocatalyst is a C2-C10 monoalcohol or a C2-C8 monocarboxylic acid, preferably valeric acid. In addition, the present invention demonstrates that i-butene can be oligomerized to heavy hydrocarbon fractions without comonomers and by a one-step process.

The process according to the present invention can replace light fractions of poly-i-butenes and polybutylenes having a number average molecular weight of 110 ... n. 650 25 or even 850 g / mol.

The present invention relates to a process for the oligomerization of 1-butene which can produce poly-n-butenes having a number average molecular weight in the above-mentioned range.

30 4 90231 ΚλΥΤΓό

Oligomers of short-chain olefins are technically important intermediates that can be used to prepare a wide variety of end products. Of the short chain olefins, the most important are propylene and the various isomers of butene and pentene. Butylene oligomers with Mn = 110 ... 2500 g / mol are used e.g. as solvents, fuels, in the manufacture of chemical cabbages and in the manufacture of lubricants and their additives.

The 1-butene oligomers prepared in accordance with this invention, also known as poly-n-butenes, contain an olefinic double bond in the polymer chain with increased reactivity. Their molecular weights have a polydispersity Mw / Mn = 1.02 ... 1.5. Among the properties of oligomers, e.g. resistance to oxidation by lammona, low pour point, low volatility, good temperature-viscosity dependence. The above properties are important 15 especially if oligomers are used in the production of lubricants and their additives. Due to the reactive double bond, oligomers can be used as selected products in the production of various chemical compounds. In the manufacture of chemicals, oligomers of 1-butene are used e.g. for the preparation of alkylbenzenes, alkylphenols and alkylsuccinic anhydride. Alkylbenzenes and phenols are prepared by sulfonating surfactants. In lubricant additives, oligomers of 1-butene can be used e.g. sulfonates, phenates, thiophosphonates and ashless dispersants, alkenyl succinimides. In these compounds the molecular weight of the hydrocarbon moiety is about 350 to 1200 g / mol, in alkenyl succinimide up to 2500 g / mol. Other applications include e.g. as a lubricant in two-stroke spark ignition engines, as a working oil for metallurgical materials in rolling and drawing, in the leather and rubber industries and in rendering various surfaces hydrophobic. Hydrogenation of oligomers can produce high quality transformer oils, electrical insulation and cable oils, as well as non-toxic cosmetic oils and white oils.

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EXAMPLES

In order to illustrate in detail the oligomerization of 1-butene according to the present invention, the following examples are given, which, however, do not limit the scope of the invention in any way.

The oligomerization reactions of 1-butene were carried out, unless otherwise stated, as follows: A steel reactor having a volume of 300 ml was cooled internally with a cooling coil and, if necessary, heated externally with an electric bath. The reactor was equipped with a stirrer. 1-Butene and catalyst were fed to the reactor via a valve to the liquid phase. The temperature of the reaction mixture was monitored with a thermocouple. The temperature of the reaction mixture was kept within ± 1 ° C of the set point. The reactor was charged under a nitrogen atmosphere with 100 ml of n-heptane as solvent and the amount of cocatalyst mentioned in the example. The solvent was dried through molecular sieves. Thereafter, 60-70 g of liquid 1-butene was fed to the reactor. After the addition of the monomer, the reactor was pressurized with BF 3 gas to form the catalyst complex in situ and the reaction started immediately. The reactor pressure was kept constant by BF3 gas. The reaction parameters used were as follows: pressure 2.5 to 10 bar expressed as overpressure, reaction temperature 10 to 70 ° C and reaction time 1 to 121 minutes or 1 to 6 hours. The reaction was quenched by the addition of excess either NaOH solution or water to the reactor. The product fraction was washed with NaOH solution and then with water until the pH of the fraction was in the neutral range. The product distribution was determined by the GC method.

Examples 1 and 2.

As cocatalyst, 14.2 mmol of n-valeric acid per mole of 1-butene were used. The reactor pressure was 4.0 bar and the temperature was 20 ° C. In Example 1 the reaction time was 9 minutes and in Example 2 49 minutes. After said reaction times, the reactions were quenched with NaOH solution. The hydrocarbon phases were analyzed to give the following results: 30 6 90231

Selectivities C4 conver. Cg C12 C16 C20 C24 C28 C32 +

Example 1 77.4% - 10.5 51.5 28.2 8.0 1.8

Eg 2 91.0% 0.3 5.0 15.8 15.3 22.8 18.5 22.3 5

The number average molecular weights of the product distributions according to the examples were 237 g / mol and 310 g / mol. The light fractions (C16) were separated from the product of Example 2 by vacuum distillation at Mn = 360 g / mol.

10 Examples 3 and 4,

As cocatalyst, 5.1 mmol of n-valeric acid per mole of 1-butene were used. The reactor pressure was 4.0 bar and the temperature was 20 ° C. In Example 3, the reaction time was 9 minutes and in Example 4, 49 minutes. After said reaction times, the reactions were stopped with NaOH solution. The hydrocarbon phases were analyzed with the following results:

Selectivities C4 conver. C8 C, 2 C16 C20 C24 C28 C32 + 20 Eg 3 84.6% - 7.7 23.2 36.2 24.0 8.9

Eg 4 92.7% 0.4 1.2 4.1 12.8 18.9 14.8 47.0

The number average molecular weights of the product distributions according to the examples were 268 g / mol and 383 g / mol. From the product of Example 4, light fractions (C16) were separated by vacuum distillation, where Mn = 407 g / mol. For this non-hydrogenated product, a viscosity index of 81 was determined with a kinematic viscosity of 4.3 cSt measured at 100 ° C.

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Examples 5 and 6.

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37.8 mmol of n-valeric acid per one mole of 1-butene were used as cocatalyst. . The reactor pressure was 4.0 bar and the temperature was 20 ° C. In Example 5, the reaction time was 9 5 minutes and in Example 6 49 minutes. After said reaction times, the reactions were stopped with NaOH solution. The hydrocarbon phases were analyzed with the following results:

Selectivities 10 C4 conver. C8 C12 C16 C20 C24 C28 C32 +

Eg 5 72.5% 0.5 34.3 32.4 10.4 16.9 5.5

Eg 6 97.0% 0.7 9.2 11.2 14.8 25.5 23.0 15.6

The number average molecular weights of the product distributions according to the examples were 220 g / mol and 302 g / mol. The light fractions (C16) of the product of Example 6 were separated by vacuum distillation, where Mn = 357 g / mol.

Example 7.

20.4 mmol of n-valeric acid per one mole of 1-butene were used as cocatalyst. The reactor pressure was 2.5 bar and the temperature was 20 ° C. In Example 7, the reaction time was 49 minutes. After said reaction time, the reaction was quenched with NaOH solution. The hydrocarbon phase was analyzed to give the following result: Selectivities C4 conver. C8 C12 C16 C20 C24 C28 C32 +

Eg 7 81.8% 0.6 43.3 40.7 10.5 3.9 1.0

The number average molar mass of the product distribution according to the example was 202 g / mol. 30

Symbol 8.

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13.0 mmol of n-valeric acid per one mole of 1-butene were used as cocatalyst. The reactor pressure was 4.0 bar and the temperature was 20 ° C. The reaction time was 6 hours. After said reaction time, the reaction was quenched with NaOH solution. The hydrocarbon phase was analyzed to give the following result:

Selectivities C4 conver. Cg C12 C] 6 C20 C24 C2g C32 + 10 Eg 8 n.99% 0.9 4.2 9.0 8.0 7.5 8.4 58.4

The number average molecular weight of the product distribution according to the example was 386 g / mol. The light fractions (C16) of the product of Example 8 were separated by vacuum distillation at Mn = 467 g / mol.

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Examples 9 and 10.

4.8 mmol of n-valeric acid per mole of 1-butene were used as cocatalyst. The reactor pressure was 10 bar and the temperature 10 ° C. In Example 9, the reaction time was 9 to 20 minutes and in Example 10 to 121 minutes. After said reaction times, the reactions were quenched with NaOH solution. The hydrocarbon phases were analyzed with the following results:

Selectivities 25 C4 conver. Cg C12 C16 C20 C24 C2g C32 +

Eg 9 53.5% 0.3 7.6 43.3 36.8 7.1 5.0

Eg 10 n.99% 0.1 1.2 4.7 23.5 21.0 18.2 31.3

The number average molecular weights of the product distributions according to the examples were 247 g / mol and 349 g / mol. The light fractions (C16) of the product of Example 10 were separated by vacuum distillation, where Mn = 365 g / mol.

Examples 11 and 12.

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4.9 mmol of n-valeric acid per mole of 1-butene were used as cocatalyst. The reactor pressure was 10 bar and the temperature 40 ° C. In Example 11, the reaction time was 4 to 5 minutes and in Example 12 to 121 minutes. After said reaction times, the reactions were stopped with NaOH solution. The hydrocarbon phases were analyzed with the following results:

Selectivities 10 C4 conver. Cg C12 C16 C20 C24 C28 C32 +

Example 11 60.6% - 6.1 21.6 36.2 23.9 12.2

Example 12 n.99% - 5.7 7.3 9.3 13.3 13.1 51.4

The number average molecular weights of the product distributions according to the examples were 275 g / mol and 371 g / mol. The light fractions (C16) were separated from the product of Example 12 by vacuum distillation at Mn = 429 g / mol. For this non-hydrogenated product, a viscosity index of 82 was determined with a kinematic viscosity of 7.0 cSt measured at 100 ° C.

20 Examples 13 and 14.

As cocatalyst, 5.0 mmol of n-valeric acid per one mole of 1-butene were used. The reactor pressure was 10 bar and the temperature 70 ° C. In Example 13 the reaction time was 9 minutes and in Example 14 121 minutes. After said reaction times, the reactions were stopped with NaOH solution. The hydrocarbon phases were analyzed to give the following results: Λ - ·

Selectivities C4-k ° Nver. C8 Cj2 C16 C20 C24 C28 C32 + 30 Ex.13 63.2% 0.9 27.1 40.3 24.4 7.3

Eg 14 n.98% - 8.8 19.7 19.0 29.5 13.4 9.6 10 90231

The number average molecular weights of the product distributions according to the examples were 219 g / mol and 286 g / mol. From the product of Example 14, light fractions (C16) were separated by vacuum distillation, where Mn = 341 g / mol.

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Examples 15 ... 21.

1-Butene is also oligomerizable with organic acid cocatalysts other than n-valeric acid, as well as alcohols and water, as shown in Examples 15-21. The reactor pressure was 4.0 bar and the temperature was 20 ° C with a reaction time of 36 minutes. Acetic acid (e.g. 15), n-octanoic acid (e.g. 16), ethanol (17), 1-pentanol (18), 1-octanol (19) and water (20) were used as cocatalysts. A comparative example is the reaction with n-valeric acid under the same conditions. The cocatalyst was used in an amount of 14.5 to 15.9 mmol of cocatalyst per mole of 1-butene.

15 cocatal. ^ kk C2g. ·. C2- ^ C2Q ... C28 ^ 32 + C ^ conversion C2 acid 15.1 57.0 43.0 - 77.0% C8 acid 14.8 17.4 59.4 23.2 83.9 % ethanol 14.5 5.4 75.4 19.2 80.4% 20 pentanol 15.9 10.0 69.9 20.1 74.8% octanol 14.5 22.7 61.1 16.2 79 , 2% water 15.0 12.7 87.3 - 61.2% n-valer.h. 15.0 18.3 59.7 22.0 86.7% 25

Claims (7)

11 90231 A process for the oligomerization of 1-butene, characterized in that the i-butene is oligomerized in one step between BF3 and a C2-C10 monoalcohol or Process according to claim 1, characterized in that said monocarboxylic acid is n-valeric acid, i-valeric acid, methylbutanoic acid or a mixture thereof. Process according to Claim 1 or 2, characterized in that the temperature in the oligomerization reaction is 0 to 90 ° C. Process according to Claim 1, 2 or 3, characterized in that the total pressure of the oligomerization reaction is 1 to 15 bar. Process according to one of Claims 1 to 4, characterized in that the reaction time of the oligomerization reaction is 0.5 to 10 hours. 5 with a complex of C2-C8 monocarboxylic acid to a hydrocarbon containing 12 to 48 carbon atoms, such that the BF3 complex is formed in situ at constant BF3 pressure by first loading an inert solvent, a cocatalyst and i-butene into the reactor. Process according to one of Claims 1 to 5, characterized in that the inert solvent is an alkane or a cycloalkane, preferably n-heptane. Use of a 1-butene oligomomer prepared by a process according to any one of claims 1 to 6 as a solvent or intermediate in the preparation of lubricants or their additives. 12 90231