DE102005030659A1 - Method of processing acid-catalyzed reaction of olefin in liquid phase comprises terminating reaction mixture by adding aliphatic nitrile, separating into nitrile-rich- and nitrile-poor phase, and further reconditioning product-phase - Google Patents

Abstract

Method for processing reaction mixture of acid-catalyzed reaction of olefin in liquid phase in the presence of at least a Lewis acid halogen compound catalyst, comprises terminating the reaction by adding aliphatic nitrile (0.5-10 mol per mole of Lewis acid halogen compound) to the reaction mixture, separating the reaction mixture into nitrile-rich phase and nitrile-poor product phase; separating the nitrile-rich phase of the nitrile-poor product phase and further reconditioning the product phase, where the nitrile is 2 or 3C-mononitrile or 3-6C -dinitirile. Method for processing reaction mixture of acid-catalyzed reaction of olefin in liquid phase in the presence of at least a Lewis acid halogen compound catalyst, comprises terminating the reaction by adding aliphatic nitrile (0.5-10 mol per mole of Lewis acid halogen compound) to the reaction mixture, separating the reaction mixture into nitrile-rich phase and nitrile-poor product phase; separating the nitrile-rich phase of the nitrile-poor product phase and further reconditioning the product phase, where the nitrile is 2 or 3C-mononitrile or 3-6C -dinitirile. An independent claim is included for a procedure for the production of polyisobutene by polymerization of an isobutene containing hydrocarbon stream in presence of complex catalyst such as boron trifluoride and at least an oxygen-containing compound, comprising the above process.

Description

The The present invention relates to a process for the processing of Reaction mixtures of acid-catalyzed Reactions of olefins in liquid Phase in the presence of catalytic amounts of at least one Lewis acid Halogen compound.

A Row of by Lewis acids catalyzed reactions of olefins are used on an industrial scale, for example, in the alkylation of phenols and olefin alkylation (See, for example, WO 2004/050806 and references cited therein), in which Polymerization of isobutene (see for example EP-A-145235, EP-A-628575, EP-A-742191 and WO 99/31151), in the oligomerization of linear 1-olefins such as 1-decene (see, for example, WO 2004/022511 and references cited therein) as well as in the polymerization of vinyl ethers, tetrahydrofuran or Styrene.

In As a rule, the catalyst used in these reactions is one or more lewissaure halogen compounds, optionally together with a or more cocatalysts used. Due to the high reactivity lewissaurer Halogen compounds become the reactions typically under protic conditions aborted, e.g. by adding water, alcohols or water or alcoholic bases. This is a solvolysis of Lewis acids Halogen compound to form hydrogen halides instead. The latter, however, are highly corrosive, requiring appropriate action must be taken against corrosion. In addition, this way a big part or the total amount of catalyst in the wastewater, resulting in more economical and more ecological View not desirable is. Furthermore, leads the protic demolition frequently to problems in the phase separation of hydrolyzate and product phase. However, it proves to be particularly problematic that this Way additional Halogen is introduced into the desired product, which for many Applications unwanted is.

There has therefore been no lack of attempts to separate at least parts of the Lewis acid halogen compounds while avoiding a protic termination of the reaction mixture of such a reaction. A number of patent applications describe the removal of boron trifluoride from reaction mixtures of an oligomerization of α-olefins by absorption on silica gel or on polyvinyl alcohol (see, eg US 4,454,366 . US 4,384,162 . US 4,433,197 . US 4,429,177 and cited literature). However, these methods are problematic not least because of the input of solids in their implementation.

The EP-A-742191 suggests before, a boron trifluoride-containing product stream of a boron trifluoride-catalyzed olefin oligomerization to split thermally and the liberated boron trifluoride in to introduce the educt current. However, this procedure is due the thermal treatment of the product flow in the first place limited the oligomerization of 1-olefins.

The WO 99/31151 describes the polymerization of isobutene in the presence a boron trifluoride complex catalyst in which by lowering of the isobutene content in the reaction mixture to less than 2 wt .-% of a partial deposition a boron trifluoride-rich phase causes this phase separated and recycled to the polymerization. On This way, however, larger amounts remain on boron trifluoride in the product stream, which in a conventional manner, e.g. protic, must be disabled. Get in this way big amount of of fluorine in the sewage. In addition, the fluorine content of the obtained Products not satisfactory.

Out EP-A-145235 is known to catalyze the reaction mixture of a boron trifluoride Disable isobutene polymerization by adding acetonitrile. The thus deactivated reaction mixture is then a water wash subjected. In this way, the above-mentioned problems naturally do not become solved.

Of the The present invention is therefore based on the object, a method for the work-up of reaction mixtures used in the reaction of olefins using Lewis Acid-based catalysts Halogen compounds are obtained to provide it allows reduce the halogen content in the waste water and in the product.

This object is surprisingly achieved by a method in which such Um tion by adding 0.5 to 10 moles of at least one aliphatic nitrile per mole of Lewis acid halogen compound to the reaction mixture, causing a separation of the resulting reaction mixture in a nitrile-rich phase and a nitrile-poor product phase and at least the majority of the nitrile rich phase separated from the nitrile-poor product phase. The aliphatic nitrile is selected from aliphatic mononitriles having 2 or 3 C atoms and aliphatic dinitriles having 3 to 6 C atoms. The product phase is then sent to a further workup.

The The present invention thus relates to a process for working up of reaction mixtures of acid-catalyzed Reactions of olefins in liquid Phase in the presence of catalytic amounts of at least one Lewis acid Halogen compound, characterized in that the reaction by adding from 0.5 to 10 mol of at least one aliphatic nitrile breaks off per mole of Lewis acid halogen compound to the reaction mixture, a separation of the reaction mixture thus obtained in a nitrile-rich Phase and a nitrile-poor product phase causes the bulk the nitrile-rich phase separates from the nitrile-poor product phase and the product phase for further processing, wherein the aliphatic nitrile selected is among aliphatic mononitriles having 2 or 3 C atoms as well aliphatic dinitriles having 3 to 6 carbon atoms.

The inventive method allows not just an immediate reaction abort and easy separation the catalytically active Lewis acid halogen compound from the reaction mixture but surprisingly delivers also products with a very low Halogen content, even at longer Storage does not increase. Other than those described in the prior art Method, is the inventive method generally for the work-up of reaction mixtures suitable in the reaction of olefins in the presence of catalytically active, Lewis acid halogen compounds to be obtained. In addition, the Lewis acid halogen compound can often be the nitrile-rich phase recovered and fed again to the implementation be, both in terms of profitability as well on the environmental compatibility the implementation is advantageous. In any case, one is extensive or complete Removal of the Lewis acid compound from the reaction mixture possible, without that it's a water wash requires, so that by the workup of the invention, the burden reduced waste water with halogen and other catalyst residues.

The inventive method can be used to work up reaction mixtures, obtained by a batch or semi-batch process. However, it is particularly suitable for working up reaction mixtures, which were obtained in a continuous reaction of the olefin.

When Nitriles can in the process according to the invention all aliphatic mono- and dinitriles are used, in which The relationship of nitrile groups to the total number of carbon atoms in the range from 1: 1.5 to 1: 3, e.g. Acetonitrile, propionitrile, malononitrile, succinodinitrile and adiponitrile. Preferred nitrile is acetonitrile.

In usually the addition of the nitrile takes place at a time when the desired one Sales is reached. In general, sales, based on the used olefin, at least 50% and especially at least 80% be.

at the continuous reaction of olefins, e.g. in the polymerization Of olefins, one will often implement the reaction so that the concentration not to set olefin in the reactor output not more than 50 Wt .-%, in particular not more than 30 wt .-% and especially not more than 10% by weight, e.g. 0.1 to 50% by weight or 0.5 to 30% by weight or 1 to 10 wt .-% is.

at the continuous production of polyisobutene is the isobutene concentration preferably less than 50% by weight at the time of termination, especially preferably less than 30% by weight and most preferably less as 10 wt .-%, based to the reaction mixture (= reactor discharge). In continuous Reactions, the nitrile is added typically to the reactor.

Preferably one gives the nitrile at a temperature below 20 ° C, in particular below 10 ° C and more preferably below 0 ° C to. In particular, the addition of the nitrile takes place at temperatures in the range of -50 ° C to <0 ° C. In general it takes place at the reaction temperature to after complex separation the Cold to Cooling to use the reactor feed.

The added amount of nitrile is advantageously 1.0 to 10 moles per mole of Lewis acid halo genverbindung, in particular 1.1 to 5 moles per mole of Lewis acid halogen compound and especially 1.2 to 2 moles per mole of Lewis acid halogen compound.

The Addition of the nitrile is usually carried out in a manner in which ensures thorough mixing of the nitrile with the reaction mixture is, e.g. by using dynamic mixing devices such as stirrer or Mixing pumps or in the case of a continuous reaction also using static mixing elements or mixing pumps.

By the addition of the nitrile is not only a termination of the reaction but also to a formation of a nitrile-rich phase, which the total amount or almost the total amount of the Lewis acid halogen compound contains in the reaction mixture. In other words, form in the reaction mixture a dispersively distributed nitrile-rich phase, which lewissaure the Contains halogen compound, and a coherent one Nitrile-poor product phase, which is the reaction product of the reaction of the olefin. The first extremely fine in the reaction mixture dispersed disperse phase, at least partially coalescing into larger droplets, due to the higher density compared to the product phase at higher Concentrations, at least partially settle and thus from the Reactor, optionally together with small amounts of the product phase, be discharged or returned to demolition to the mixing elements can.

to advancement the coalescence of the primary Forming finely divided nitrile-rich droplets will usually be common measures to promote take the phase separation, for example, slow stirring, heating, extension residence times, absorption on hydrophilic surfaces, the Application of Koalisierfiltern, the return promotion deposited complex for termination or separation of an organic phase by ultrafiltration or microfiltration.

The Addition of the nitrile and the separation of the nitrile-rich phase can also in the form of a single-stage or multi-stage, continuous or discontinuously operated liquid-liquid extraction. Suitable devices for the liquid-liquid extraction are familiar to the expert and usually comprise units for mixing with subsequent ones settling tanks, preferably lying settling tanks and multi-stage extraction columns, including pulsating extraction columns.

in the inventive method it has proved to be advantageous if, after separation of a Part of the nitrile-rich phase in the manner described above the so depleted of nitrile and the lewissauren halogen compound Product flow passes through a filter for additional amounts of nitrile-rich phase and thus to Lewis acid halogen compound from the product stream to remove. Preference is given to such filters with small pore sizes of not more than 50 μm. Which includes Coalescing filters, which typically have pore sizes in the range of 1 to 50 μm, often in the range of 5 to 50 μm but also membrane and paper filters with pore widths of not more than 5 μm, e.g. in the range of 0.5 to 5 microns.

In usually one will proceed in such a way that one first the Part of the present in the reaction mixture nitrile-rich phase, the spontaneously koalisiert, over a device for phase separation, e.g. with the help of separators, Separators, settling tanks preferably with a bed separated from finely divided materials with a high specific surface area and separating the residual amount of nitrile-rich phase via a performs the aforementioned filter. The finely divided material of the bed has preferably a hydrophilic surface or a surface that strong with the polar complex of nitrile and Lewis acid compound Interaction shows up. an example of such a material is Alumina, e.g. Alumina spheres

in the A case of poor phase separation can also affect a fine-pored filtration resorted be as they are, for example used in dispersion wastewater. you works with methods of micro- or ultrafiltration. typical Filter materials for this are cellulose, teflon with polyester fabric, polyamide, polyester sulfone. Preferably, the filter surfaces flowed across, so that circulation and filtration direction approximately at right angles to each other stand. The filtrate thus obtained is free of dispenser phase. The Retentate containing the dispersion is concentrated, i. the content of the dispenser phase increases and in our case leads to phase separation. So get you have two "pure" phases and one third disperse phase as a disperse mixture of pure phases. typical Pore sizes here are between 0.1 and 5 μ. Hydrophobic membranes such as Teflon could be beneficial.

The nitrile-poor product stream thus obtained typically contains only very small amounts or no Lewis acid halogen compound. It is then usually fed to a further workup. The Work-up depends in a manner known per se on the reaction product to be worked up and on the nature of the reaction. In general, the further work-up of the product stream comprises a distillation. In this case, optionally present solvent, unreacted olefins, low molecular weight by-products, in particular halogenated by-products and other volatile compounds are separated from the generally difficult volatile main product. If the reaction is carried out in an organic solvent, this, optionally together with the separated, unreacted olefin can be recycled to the reaction.

Possibly can Remaining amounts of Lewis acid compound and nitrile also removed by a conventional water wash become. This water wash typically takes place before a distillative workup of the Product stream.

In some cases, especially in reactions in the presence of boron trifluoride as Lewissaure halogen compound, it has been proven that after separation the nitrile-rich phase, the product phase with an inorganic Absorbent treated. In this way, the fluorine content in Reduce the final product further. The reaction mixture can before the Adsorbent treatment various other treatments, e.g. a wash with water for deactivation / removal of catalyst traces and / or removal volatile Components are subjected.

at The absorption treatment will probably be the halogenated By-products cleaved and the halogenated fission products, such as Hydrogen fluoride, adsorbed on the zeolite or alumina or by the cations are chemically bound. To an unwanted activation and / or structural change of Absorbent to prevent, it is preferred that in the reaction contained and / or in the cleavage of the halogenated products / by-products formed hydrogen halide by addition of an acid scavenger, for example: an amine or a nitrile to bind.

In In this context, it has proved to be advantageous that the Product phase frequently still contains low levels of nitrile, which is typically in the range from 10 to 200 ppm, especially 20 to 100 ppm, based on the Present product stream. Optionally, you can the absorbent also pretreat with solid cyanides such as alkali cyanides, e.g. by doing the adsorbent is impregnated with a solution of the cyanide and dries.

To the Contacting the product stream with the adsorbent are all conceivable discontinuous and continuous processes suitable. So you can the product stream in portions with the adsorbent offset, preferably with mechanical movement, and after sufficient Separating residence time, e.g. by filtration, decanting or another suitable method. Conveniently, however, is the adsorbent in a fixed bed ago, in an adsorption column is arranged, through which the product stream is passed. The adsorption column is preferably arranged vertically and is the material flow in the direction flows through gravity or preferably against gravity. It can too several adsorption columns connected in series can be used.

The Treatment with the adsorbent is generally carried out at a temperature of -30 up to 100 ° C, preferably -20 up to 85 ° C, when the adsorbent or the adsorbent combination comprises at least one zeolite. The treatment is preferably at a temperature of 130 to 240 ° C, in particular 150 to 230 ° C, when the Adsorbent or the adsorbent combination no zeolite includes, and e.g. as sole adsorbent alumina is used. The residence time, i. the time during the the reaction mixture is in contact with the adsorbent, is preferably 10 to 100 minutes.

The inorganic adsorbent usually comprises oxides of Si, Al, Zr and / or Ti; it is preferably selected from alumina, zeolites, SiO ₂ and combinations thereof.

In a preferred embodiment alumina is used as the adsorbent. The alumina is preferably activated before use by passing it heated under reduced pressure to a temperature of at least 150 ° C.

In other preferred embodiments, the adsorbent comprises a zeolite having mean pore sizes of 5 to 15 Å. The mean pore size is determined by the crystal structure of the zeolite and can be determined, for example, from X-ray structural data. In zeolites with smaller mean pore sizes, the fluorinated by-products can diffuse poorly and are therefore insufficiently split / adsorbed. Larger average pore zeolites can lead to increased side reactions, eg, double bond isomerization, especially when activated by traces of hydrogen fluoride or water.

preferred Zeolites are among zeolite A, zeolite L, zeolite X and zeolite Y selected. Sodium zeolite A or sodium zeolite A, in which the sodium ions completely or partially replaced by magnesium and / or calcium ions are particularly preferred.

Of the Zeolite is preferably substantially free of acid to prevent excessive side reaction, e.g. in the case of the polyisobutene, a double bond isomerization the terminal methylidene double bonds to thermodynamically more stable To avoid double bonds inside the macromolecule. One therefore uses preferably non-activated zeolites, i. those that charge compensation the negative framework load do not contain protons.

It is advantageous that the product stream after the removal of the nitrile-rich Phase and before the absorbent treatment to dry and entrained traces of water largely removed, e.g. to less than 5 ppm, preferably less than 3 ppm. Preferably, the product stream is treated in suitable way to the coalescence of the remaining nitrile phase to promote, e.g. by filtration over a coalescing filter. To further reduce the water content, you can see the polyisobutene with a zeolite of an average Pore size of 4 Å or less bring in contact, preferably at a temperature of less as 40 ° C, e.g. -30 up to 35 ° C.

In a preferred embodiment Therefore, you bring the product stream after the removal of the nitrile-rich Phase successively with (i) a first zeolite of an average Pore size of 4 Å or less, preferably at a temperature of -30 to 35 ° C, and (ii) an alumina or aluminosilicate, preferably at a temperature of 40 to 230 ° C, in Contact. The alumina may be doped with phosphate or fluoride be.

In a particularly preferred embodiment bringing the product stream successively with (i) alumina, (ii) a first zeolite having an average pore size of 4 Å or less and (iii) a second average pore size zeolite of 5 to 15 Å in Contact. The alumina of both embodiments can with a Base, such as an alkali or alkaline earth metal hydroxide, or a Alkali or alkaline earth cyanide be doped.

After adsorption, the diluent and optionally the unreacted olefin are separated, usually by distillation, unless they have already been removed before the adsorbent treatment. The distilled-off diluent can be recycled to the polymerization reactor, preferably without further treatment. If a C ₄ -hydrocarbon stream is used as isobutene source in the production of polyisobutene, the isobutene-depleted stream is preferably not recycled, but fed to a further use, for example a hydroformylation of the linear butenes contained therein to butyraldehyde or the production of alkylate or the dimerization to octenes ,

To Separation of the diluent becomes the residue, the desired one Contains products in usual Way worked up. fugitive By-products, e.g. Oligomers of the olefin used, together with diluent residues according to usual Methods removed by distillation, e.g. at temperatures up to 230 ° C in a vacuum. Circulation evaporators, falling-film evaporators, thin-film evaporators, Sambay evaporator, annular gap evaporator and the like.

The inventive method is particularly suitable for the workup of such reaction mixtures, which at least 95% by weight, based on the total weight of the reaction mixture, and in particular at least 98% by weight, of hydrocarbons, including the unreacted olefins, and / or haloalkanes, at 20 ° C and 1 bar have a density of not more than 0.9 g / ml, and the reaction products consist of olefins. In particular, it has been proven, if the reaction mixture to be worked up less than 5 wt .-% and in particular less than 2% by weight of halogenated hydrocarbons with a density> 1 g / ml (at 20 ° C and 1 bar) such as dichloromethane, dichloroethane or trichloromethane.

As already mentioned in the introduction, is the inventive method in principle for any Reactions of olefins in the presence of Lewis acid halogen compounds suitable. In particular, the process is suitable for working up of reaction mixtures in which the Lewis acid halogen compound selected is among halogen compounds of boron, aluminum, titanium and the zirkon.

Examples for lewissaure Halogen compounds of boron are in particular boron trifluoride and Boron trichloride.

Examples of Lewis acid halogen compounds are, in particular, aluminum trichloride and C ₁ -C ₄ -alkylaluminum dichlorides, such as ethylaluminum dichloride.

Examples for halogen compounds of titanium are in particular titanium tetrachloride, but also dihalometallocene compounds of titanium tetrachloride such as bis (alkylcyclopentadienyl) titanium dichloride.

Examples for halogen compounds of the zirconium are in particular zirconium tetrachloride and also dihalogenometallocene compounds zirconium such as bis (alkylcyclopentadienyl) zirconium dichloride.

By dihalogenometallocene compounds of the zirconium are meant compounds of the formula Cp ₂ MX ¹ X ² wherein M is titanium or zirconium, Cp _{2 is} a pair of optionally substituted cyclopentadienyl ligands and X ¹ and X ^{2 are} independently halogen and especially Chlorine stand. Examples of suitable dihalogenometallocene complexes of titanium and zirconium are:
Bis (n-octadecylcyclopentadienyl) zirconium dichloride,
Bis (trimethylsilyl) zirconium,
(Tetrahydroindenyl) zirconium,
Bis [(tert-butyldimethylsilyl) cyclopentadienyl] zirconium dichloride,
(Ethylidene-bisindenyl) zirconium dichloride,
Ethylidene bis (tetrahydroindenyl) zirconium dichloride and
Bis [3,3 (2-methyl-benzindenyl)] dimethylsilanediylzirconium dichloride and corresponding compounds of titanium.

In a particularly preferred embodiment the method according to the invention the Lewis acidic halogen compound is boron trifluoride.

The process according to the invention is suitable, as already mentioned at the beginning, for working up a large number of reactions of olefins catalyzed by Lewis acid halogen compounds. In a preferred embodiment, the acid-catalyzed reaction is the oligomerization or polymerization of C ₃ -C ₂₀ olefins. Such methods are known, for example from the cited prior art, to which reference is hereby made in its entirety.

Especially the method according to the invention is suitable for working up of reaction mixtures used in the preparation of polyisobutylene, in particular of polyisobutene having a number-average molecular weight from 400 to 50,000 and a content of methylidene groups of more than 50 mol% incurred by polymerization of isobutene-containing hydrocarbon streams.

According to one particularly preferred embodiment the invention is in the implementation of the olefin to the Polymerization of an isobutene-containing hydrocarbon stream in Presence of boron trifluoride and at least one oxygen-containing Connection. In this way, in particular polyisobutenes with a number average molecular weight of 400 to 50,000 and a Content of methylidene groups of more than 50 mol% available. In particular, these are methods of preparation of polyisobutene having a number average molecular weight in the range from 500 to 5000, in particular 700 to 2500. The dispersity (D = Mw / Mn) the polyisobutene is typically less than 2.5, preferably less than 2.0 and in particular less than 1.8. Processes for this purpose are those skilled in the art well known, e.g. cited from the entrance prior art and WO 01/27172, WO 01/30868, WO 01/36860, WO 02/06359, WO 02/14385, WO 2004/029099, WO 2004/065432 and in these documents cited literature.

Suitable isobutene-containing hydrocarbons are both isobutene itself and also isobutene-containing C ₄ -hydrocarbon streams, for example C ₄ -refins, C ₄ cuts from isobutane dehydrogenation, C ₄ cuts from steam crackers, FCC crackers (fluid catalyst cracking) provided they are substantially exempt from 1,3-butadiene present therein. Isobutene-containing C ₄ -hydrocarbon streams which are suitable according to the invention generally contain less than 1000 ppm, preferably less than 200 ppm of butadiene. Typically, the concentration of 1-butene, cis-, and trans-2-butene in the C ₄ hydrocarbon streams is in the range of 40 to 60 weight percent. Such C ₄ hydrocarbon streams are preferred feedstocks for the process of the present invention. When C ₄ cuts are used as starting material, the hydrocarbons other than isobutene assume the role of an inert diluent.

by virtue of high viscosity the polyisobutenes, the polymerization takes place in the presence of a Diluent. For the inventive method are such diluents or mixtures suitable to the reagents used are inert. Suitable diluents are saturated or unsaturated aliphatic, cycloaliphatic and aromatic hydrocarbons, for example, saturated hydrocarbons, such as butane, pentane, hexane, heptane, octane e.g. n-hexane, i-octane, cyclopentane, Cyclohexane, methylcyclohexane, toluene, xylenes or ethylbenzene; such as Mixtures of the aforementioned compounds. As a diluent Isobutene itself can also be used if the polymerization operated only up to a partial turnover. Preferably the diluents prior to their use in the inventive process of impurities like water, carboxylic acids or mineral acids largely or completely freed, for example by adsorption on solid adsorbents, such as activated carbon, alumina, molecular sieves or ion exchangers.

When Catalysts are preferred boron trifluoride complex catalysts. This is understood to mean catalysts of boron trifluoride and at least a, usually oxygen-containing compound as cocatalyst. The cocatalyst is capable of protons or carbon cations under reaction conditions to build. examples for Oxygenated compounds suitable as cocatalysts In particular, alkanols having 1 to 18 C atoms, in particular with 1 to 10 carbon atoms, dialkyl ethers having a total of 5 to 20 carbon atoms, in particular 5 to 12 carbon atoms, phenols, as well as aldehydes and ketones with each up to 20 C atoms, e.g. 2 to 10 carbon atoms. Suitable cocatalysts but are also hydrogen halides, especially hydrogen fluoride.

Preferably, the oxygen-containing compound is selected from primary and secondary C ₁ -C ₅ alkanols, and mixtures of at least one primary or secondary C ₁ -C ₅ alkanol with at least one further oxygen-containing compound selected from C ₆ -C _{1 2} alkanols and Dialkyl ethers having a total of 5 to 12 carbon atoms. The molar ratio of oxygen-containing compound to boron trifluoride is in particular in the range from 0: 9: 1 to 3: 1.

• – L¹ für ein primäres C₁-C₅-Alkanol, ein sekundäres C₃-C₅-Alkanol, ein Phenol B.und/oder einen tert-Butylether, z. tert.-Buylmethylether, steht,
• – L² für wenigstens einen Aldehyd und/oder ein Keton mit vorzugsweise 2 bis 10 C-Atomen, steht,
• – L³ für einen von einem tert-Butylether verschiedenen Ether mit wenigstens 5 Kohlenstoffatomen, ein sekundäres Alkanol mit wenigstens 6 Kohlenstoffatomen, z.B. 6 bis 12 C-Atomen, ein primäres Alkanol mit wenigstens 6 Kohlenstoffatomen, z.B. 6 bis 12 C-Atomen, und/oder ein tertiäres Alkanol mit 4 bis 12 C-Atomen steht,
• – das Verhältnis b:a im Bereich von 0,9 bis 3,0, vorzugsweise 1,1 bis 2,5, liegt,
• – das Verhältnis c:a im Bereich von 0 bis 0,5, vorzugsweise 0 bis 0,3, liegt,
• – das Verhältnis d:a im Bereich von 0 bis 1,0, vorzugsweise 0,1 bis 1, insbesondere 0,1 bis 0,6, liegt.

Particular preference is given to using boron trifluoride complex catalysts which have the following composition: (BF 3 ) a · L 1 b · L 2 c · L 3 d wherein

• L ^{1 is} a primary C ₁ -C ₅ alkanol, a secondary C ₃ -C ₅ alkanol, a phenol B and / or a tert-butyl ether, e.g. tert-butyl methyl ether,
• L ^{2 represents} at least one aldehyde and / or one ketone having preferably 2 to 10 C atoms,
• L ^{3 is} an ether other than a tert-butyl ether having at least 5 carbon atoms, a secondary alkanol having at least 6 carbon atoms, eg 6 to 12 C atoms, a primary alkanol having at least 6 carbon atoms, eg 6 to 12 C atoms, and / or a tertiary alkanol having 4 to 12 C atoms,
• The ratio b: a is in the range from 0.9 to 3.0, preferably 1.1 to 2.5,
• The ratio c: a lies in the range from 0 to 0.5, preferably 0 to 0.3,
• The ratio d: a is in the range from 0 to 1.0, preferably 0.1 to 1, in particular 0.1 to 0.6.

Compounds L ¹ are also referred to as "starter" or "initiator", because their active hydrogen atom or t-butyl cation is incorporated at the beginning of the growing polyisobutene. In addition, tert-butyl ethers, such as tert-butyl methyl ether (MTBE), which readily form a tert-butyl cation, phenols, such as phenol or cresols are suitable. As L ¹ , methanol, ethanol, 2-propanol and / or 1-propanol and / or MTBE are preferred. Of these, methanol or methanol / MTBE is most preferred.

Aldehydes and / or ketones, which usually comprise one to 20, preferably 2 to 10, carbon atoms and in which preferably functional groups other than the carbonyl group are absent, may also be used as regulator L ² . As L ² , for example, formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, acetone, methyl ethyl ketone and diethyl ketone are suitable. Acetone is the most preferred.

The solubilizers L ³ have a solubilizing effect and increase the solubility of the catalyst complex in the feedstock. These are ethers having at least 5 carbon atoms, which are different from tert-butyl ethers, or long-chain and / or sterically hindered alcohols which provide shielding against the access of isobutene molecules. It is preferable to use dialkyl ethers having 5 to 20 Koh lenstoffatomen, a secondary alkanol having 6 to 20 carbon atoms, a primary alkanol having 6 to 20 carbon atoms and / or a tertiary C ₄ -C ₂₀ alkanol. When primary alkanols are used, they preferably have a β-branch, ie, a branch on the adjacent carbon atom to the carbon atom bearing the hydroxyl group. Suitable representatives are, for example, di-n-butyl ether, di-n-hexyl ether, dioctyl ether, 2-ethylhexanol, 2-propylheptanol, the oxo alcohols of di-, tri- and tetramerpropylene and di- and trimerbutene, linear 1-alcohols (eg obtainable by the Alfol® ^methods ), if they are liquid under reaction conditions, such as n-hexanol or n-octanol, and tert-butanol. Of these, 2-ethylhexanol is most preferred.

The BF ₃ concentration in the reactor is generally in the range of 0.005 to 1 wt .-%, based on the liquid reaction phase, in particular in the range of 0.01 to 0.7 wt .-% and especially in the range of 0, 02 to 0.5 wt .-%.

The Boron trifluoride complexes, if soluble in the reaction mixture, can be dissolved in separate reactors prior to their use in the process according to the invention be preformed, stored after their formation and depending on Demand be metered into the polymerization. Another, preferred variant, especially for sparingly soluble complexes, is that the boron trifluoride complexes in situ in the polymerization or a feed generated. In this procedure, the respective Cocatalyst optionally together with a solvent fed to the polymerization or the feed and Boron trifluoride in the required amount in this mixture of Reactants solved or dispersed as a complex. This is the boron trifluoride and the cocatalyst to the boron trifluoride complex. Instead of a additional solvent may be due to in situ generation of the boron trifluoride catalyst complex the reaction mixture of unreacted isobutene and polyisobutene as a solvent act.

The Polymerization of isobutene is preferably carried out in a continuous Method. activities for the continuous polymerization of isobutene in the presence of boron trifluoride-containing Catalysts in inert organic solvents to Polyisobu th are known per se. In a continuous process is continuously part of the resulting in the polymerization reactor Reaction mixture discharged. An amount corresponding to the discharge Feedstock becomes continuous to the polymerization reactor supplied and mixed with a circulating amount. The ratio of circulating volume to inflow is usually in the range of 1000: 1 to 1: 1, preferably in the range from 500: 1 to 5: 1, and more preferably in the range of 20: 1 to 100: 1 v / v. The mean residence time of the isobutene to be polymerized in the polymerization reactor, by reaction volume and feed rate is determined may be 5 seconds to several hours. residence from 1 to 30 minutes, especially 5 to 20 minutes are preferred.

The Polymerization generally occurs at a temperature in the range from -60 ° C to + 40 ° C, preferably less than 0 ° C, more preferably in the range of -5 ° C to -40 ° C and especially in the range of -10 ° C to -30 ° C. The heat of polymerization is according to a cooling device dissipated. This can, for example, with boiling ammonia as a coolant operate. Another way, the polymerisation derive, is the Siedekühlung in the reactor. In this case, the heat released by evaporation of the isobutene and / or other more volatile Components of the isobutene feedstock or possibly volatile solvent dissipated.

The Polymerization of the isobutene is carried out in the usual manner for the continuous polymerization Reactors, such as stirred kettles, Tube, tube bundle and loop reactors wherein loop reactors, i. Tube (bundle) reactors with circulation and turbulent flow and / or internals such as static mixers, i. with stirred tank characteristics, are preferred. Very cheap are in low-viscosity reaction mixtures loop reactors with Pipe cross-sections leading to turbulent flow; in high-viscosity reaction mixtures larger pipe cross sections with static mixing elements.

In preferred embodiments you lead the polymerization in at least two consecutive reactors by, at least the first reactor in some areas backmixed is, with the moderator at least in the second and / or further Metered reactor. In preferred embodiments, one doses a first subset of the moderator in the first reactor and at least another subset in the second or further reactor. Of the Proportion of the metered in the first reactor subset of the total is presenter preferably 40 to 90%.

In the first reactor, the supplied isobutene is generally polymerized to a partial conversion of up to 95%, preferably 50 to 90%, particularly preferably 70 to 90%, based on the isobutene introduced into the first reactor. The discharge from the first reactor is preferably without further Aufar passed in the second reactor or from a preceding in the subsequent reactor. Here, the further polymerization takes place without the addition of fresh isobutene.

The Residence time of the reaction mixture in the first reactor is in the Adjustment of an isobutene conversion of 50 to 90% usually 5 to 60 minutes, but may be shorter or longer, depending on whether one very active or less active catalyst is used. in the second reactor is generally a residence time of 1 to 180, preferably set from 2 to 120 minutes. Generally in the Last reactor of isobutene conversion adjusted so that the total sales of isobutene is 90 to 99.5%. Preferably, the isobutene content is the distillate of the work-up not less than 1%, preferably not below 2%.

The Concentration of the isobutene in the liquid reaction phase in the main reactor is usually in the range of 0.2 to 50 wt .-%, preferably in the range of 0.5 to 20 wt .-% and in particular in the range of 1 to 10 wt .-%, based on the liquid reaction phase. In the Preparation of polyisobutenes with number average molecular weights Mn in the range of 500 to 5000 is preferably carried out at an isobutene concentration in the range of 1 to 20 wt .-% and in particular in the range of 1.5 to 10% by weight. In the production of polyisobutenes with a Number average molecular weight Mn of more than 5000 works preferably at an isobutene concentration in the range of 4 to 50 Wt .-%. In preferred embodiments In the first reactor, an isobutene concentration of 3% by weight does not below.

At the Leaving the last reactor, the reaction mixture usually contains 2% by weight or less of isobutene. Preferably, an isobutene concentration of 0.5 wt .-% but not below.

Preferably one works in the polymerization process according to the invention at least in the main reactor under isothermal conditions, i. the Temperature of the liquid Reaction mixture in the polymerization reactor has a steady state value and changes while the operation of the reactor not or only to a small extent. If desired For example, the polymerization in the second reactor may be at a lower polymerization temperature as done in the first reactor; it usually requires one further activation by the addition of fresh boron trifluoride or a regulator, such as an aldehyde or ketone, e.g. Acetone. It is however, preferably, the second or further reactor at a slightly higher temperature operate to reduce isobutene through thermal activation to complete. Since the polymerization is exothermic, this can be the second or another reactor under essentially adiabatic conditions operate, i. the reactor is then not actively cooled or heated and the heat of polymerization is taken up by the reaction mixture.

The is discharged from the polymerization reactor reaction mixture subsequently a work-up according to the invention supplied i.e. in the reactor discharge, the nitrile is in the amount indicated above given and subsequently is a separation of the polymerization mixture thus obtained in causes a nitrile-rich phase and a nitrile-poor product phase, the majority of the nitrile-rich phase from the low-nitrile product phase separated and fed the product phase for further work-up.

According to one another embodiment The present invention is the acid-catalyzed Reaction to the polymerization of an isobutene-containing hydrocarbon stream in the presence of at least one Lewis acid halogen compound, especially in the presence of boron trichloride or titanium tetrachloride, and at least one tertiary or allylic organic compound that is capable of a carbocation to form, e.g. a tertiary or allylic organic halogen compound. Procedures for this are also known, e.g. from EP-A 722 957, EP-A 0713 883, WO 02/048215, WO 02/048216, WO 02/96964, WO 03/074577 and WO 04/113402, to which reference may be made for further Details are referenced.

According to a further embodiment of the invention, the acid-catalyzed reaction is an oligomerization of C ₈ -C ₂₀ -olefins, in particular 1-olefins and especially 1-decene or 1-dodecene for the preparation of synthetic hydrocarbon oils. Such reactions may in principle be carried out in the presence of boron trifluoride and at least one oxygen-containing compound as catalyst or in the presence of dihalogenometallocene catalysts of zirconium or titanium, as previously mentioned. Methods for this purpose are known to the person skilled in the art, for example from WO 99/67347, US 3,149,178 . US 3,382,291 . US 3,780,128 . US 4,045,507 . US 4,045,508 . US 5,284,988 . US 5,498,815 EP-A-349276, EP-A-1006097 and WO 2004/022511. The workup process according to the invention can be used for working up the reaction mixtures obtained there. For further details regarding the reaction of the 1-olefins, reference is explicitly made to the disclosure of these documents.

The The following examples are for further explanation only of the invention and are not intended to be limiting.

I Preparation of polyisobutene in the presence of boron trifluoride complex catalysts:

For the experiment, in addition to isobutene and pentane, a so-called raffinate I was used, which was obtained by butadiene removal by extractive distillation with NMP from the C _{4 cut of} a naphtha-operated cracker. Raffinate I had the following composition:

General experiment

The reactor consisted of a Teflon hose of 7.1 m length with an inner diameter of 6 mm, over which 1000 l / h reactor contents were circulated by a gear pump. Tube and pump had a capacity of 200 ml. Teflon tube and pump head were in a cooling bath of -25 ° C (cryostat). The feed used was the aforementioned raffinate I or a mixture of aliquots of pentane and isobutene, the feed was 700 g / h. The feed was pre-dried over molecular sieve 3 A with a residence time of 10 minutes at room temperature, pre-cooled through a capillary with 2 mm internal diameter to -25 ° C. and dried over molecular sieve 3 Å in the cold bath with a residence time of 10 minutes below 1 ppm water ( Conductivity measurement) and the circulation reactor on the suction side of the circulation pump. There, BF ₃ , boranes, complexes and complexing agents were also fed there. At a reactor temperature of -18 ° C., an isobutene concentration of about 4% was obtained. To the effluent, acetonitrile was added continuously and the whole was passed through a static mixer into a settling vessel. The upper slightly cloudy phase was separated from the complex solution and filtered through a microfilter (membrane filter cassette Schleicher and Schüll membrane RC) with a pore size of 0.45 μ, whereby a clear organic polymer solution (raffinate) and a disperse retentate was obtained. The retentate was returned to the phase separation vessel. Then, at 0 ° C., it was passed over a neutral aluminum oxide column with a contact time of 5 minutes based on the volume of void, and the resulting raffinate was worked up by distillation at 230 ° C. _2mbar , GPC and N-NMR were carried out and the viscosity was measured.

Example 1: Continuous isobutene

• – 350 g/h Pentan
• – 350 g/h Isobuten
• – 8 mmol/h BF₃
• – 12 mmol/h Methanol
• – 1,2 mmol/h Ethylhexanol
• – 10 mmol Acetonitril zum Abbruch

polymerisiert und aufgearbeitet. Das Raffinat enthielt weniger als 1 ppm anorganisch Fluor. Das zahlenmittlere Molekulargewicht des nach destillativer Aufarbeitung des Raffinats erhaltenen Polymeren betrugt M_N 990 bei einer Dispersizität Mw/Mn von 1,60 und einer Reaktivität (Vinylidendoppelbindungsanteil) von 90%. Die Viskosität des Polymeren bei 100°C betrug 185 mm²/s.According to the general experimental procedure, isobutene was in the above miniplant with the following feeds:

• - 350 g / h pentane
• - 350 g / h isobutene
• - 8 mmol / h BF ₃
• - 12 mmol / h of methanol
• - 1.2 mmol / h ethylhexanol
• - 10 mmol acetonitrile to break off

polymerized and worked up. The raffinate contained less than 1 ppm of inorganic fluorine. The number average molecular weight of the polymer obtained after distillative working up of the raffinate was M _N 990 with a dispersity Mw / Mn of 1.60 and a reactivity (vinylidene double bond content) of 90%. The viscosity of the polymer at 100 ° C was 185 mm ² / s.

Example 2:

• – 700 g/h Raffinat I
• – 16 mmol/h BF₃
• – 25 mmol/h Methanol
• – 2 mmol/h Ethylhexanol
• – 1,6 mmol/h Acetonitril zum Reaktor
• – 18,4 mmol/h Acetonitril zum Abbruch

polymerisiert und aufgearbeitet. Das Raffinat enthielt 2 ppm anorganisches Fluor. Das zahlenmittlere Molekulargewicht des nach destillativer Aufarbeitung des Raffinats erhaltenen Polymeren betrugt M_N 1010 bei einer Dispersizität Mw/Mn von 1,65 und einer Reaktivität (Vinylidendoppelbindungsanteil) von 90%. Die Viskosität des Polymeren bei 100°C betrug 190 mm²/s.According to the general experimental procedure, isobutene was in the above miniplant with the following feeds:

• - 700 g / h raffinate I
• - 16 mmol / h BF ₃
• - 25 mmol / h of methanol
• - 2 mmol / h ethylhexanol
• - 1.6 mmol / h acetonitrile to the reactor
• - 18.4 mmol / h acetonitrile to demolition

polymerized and worked up. The raffinate contained 2 ppm of inorganic fluorine. The number average molecular weight of the polymer obtained after distillative workup of the raffinate was M _N 1010 with a dispersity Mw / Mn of 1.65 and a reactivity (vinylidene double bond content) of 90%. The viscosity of the polymer at 100 ° C was 190 mm ² / s.

Examples 3-9

• n.a. = nicht analysiert

Example 2 was repeated with various amounts of acetonitrile in the kill

• na = not analyzed

Example 10: Production of 1-decene oligomers

In a 1 liter four-necked flask with thermometer, dropping funnel, gas inlet tube for boron trifluoride, Gas discharge pipe with bubble counter and magnetic stirrer were 5 mmol of n-pentanol and 5 mmol of isobutyl tert-butyl ether presented and cooled to -10 ° C. Then led 10 mmol of boron trifluoride while maintaining the temperature one. Thereafter, 140 g of 1-decene were added with cooling. You removed that heat bath and allowed to warm to 30 ° C. Then was passed under vigorous stirring another 10 mmol boron trifluoride within 10 minutes in the reaction mixture one. Subsequently, a temperature of 30 ° C was maintained for 2 h. Then were added with vigorous stirring 30 mmol acetonitrile at 30 ° C to. After 15 minutes of phase separation, the acetonitrile phase became separated. The product phase thus obtained contained after filtration over a Pleated filter with pore size 5 μ less as 1 ppm of inorganic fluorine. The product phase was over a Pillar with 50 g of neutral aluminum oxide balls with 2 to 3.5 mm ball diameter sent with a residence time of 10 min and placed in a rotary evaporator of solvents, 1-decene and decene dimers released. This was done by lowering the pressure slowly to 0.1 mbar and increased the temperature continuously to 150 ° C. After 30 minutes at 150 ° C and 0.1 mbar gave a product containing less than 2 wt .-% dimer.

Example 14: Polymerization of isobutene in the presence of titanium tetrachloride / dicumyl chloride

Example 11 to 13:

The apparatus consisted of 2 four-necked flasks per 1 liter, the original A and the reaction vessel B. Both flasks were equipped with a magnetic bar, a thermometer, a septum and a dropping funnel Handling, overbuilt with a dry ice cooler equipped with drying tube and connected to each other lockable. The flasks were arranged on two magnetic stirrers with stainless steel bowls so that heating and cooling with stirring was possible. The reaction flask was additionally equipped with an IR spectrometer (React-IR 1000 from Mettler Toledo).

In of template A were presented phenathroline, hexane and n-butyl chloride, Isobutene fed to the dropping funnel so that it condensed on the dry ice condenser and was collected in the dropping funnel, emptied into the template and by means of a syringe with a 1 molar solution of Butyllithium added in hexane until it came to permanent browning for 5 min. Then the compound to the reaction vessel was opened and the contents of A distilled to B

In the reaction flask B, the initiator, 1,3-dicumyl chloride (DCC) had been previously submitted. After distilling over from A to B, the initiator was first dissolved. 1.1 g of phenyltriethoxixilane was added via syringe via the septum and cooled to -76 ° C with acetone / dry ice. Then TiCl _{4 was} added with a syringe and added after 1 hour reaction time at incomplete isobutene acetonitrile. The yellowish-brown precipitate which formed was filtered off by means of pressure filtration at 3 bar via a depth filter (Seitz, identification EKS) and a portion of the filtrate was analyzed for titanium (450 ppm), the remainder over 100 g of neutral alumina powder with a residence time of 10 Purified for a few minutes and analyzed for Ti and acetonitrile. Then at room temperature in vacuo up to 2 mbar, the solvent was removed. The residue was analyzed for molecular weight and molecular weight distribution by GPC and for functionality by ¹ H-NMR. The number average molecular weight Mn was 2227, the molecular weight distribution Mw / Mn 1.40, the isobutene conversion was 80%, the halogen functionality was 1.9, the indane functionality was 0.1. Approach: 340 ml 1-chlorobutane 146 ml isobutene 10 ml butyllithium 10.9 g 1.3 dicumylchloride 1.44 g Phenyltriethoxisilan 0.82 ml TiCl ₄

Claims (17)

A process for the treatment of reaction mixtures of acid-catalyzed reactions of olefins in the liquid phase in the presence of catalytic amounts of at least one Lewis acid halogen compound, characterized in that the reaction by addition of 0.5 to 10 moles of at least one aliphatic nitrile per mole of lewissaurer halogen compound to the Reaction mixture breaks down, a separation of the reaction mixture thus obtained in a nitrile-rich phase and a nitrile-poor product phase is effected, the majority of the nitrile-rich phase separated from the nitrile-poor product phase and the product phase for further processing, wherein the nitrile is selected under mononitriles having 2 or 3 C atoms and dinitriles having 3 to 6 C atoms. Method according to claim 1, characterized in that that the nitrile is added at a temperature of less than 0 ° C. Method according to one of the preceding claims, characterized characterized in that the aliphatic nitrile in an amount from 1.2 to 2 moles per mole of Lewis acid halogen compound to the reaction mixture to the reaction mixture. Method according to one of the preceding claims, characterized characterized in that the product phase for complete separation the nitrile-rich phase passes through a filter. Method according to one of the preceding claims, characterized characterized in that the reaction mixture contains at least 95% by weight from hydrocarbons and / or haloalkanes of one density at 20 ° C and 1 bar of not more than 0.9 g / ml and the reaction products the olefins consists. Method according to one of the preceding claims, characterized characterized in that the aliphatic nitrile is acetonitrile. Method according to one of the preceding claims, characterized in that the Lewis acid halogen compound is selected halogen compounds of boron, aluminum, zirconium and titanium. Method according to claim 7, characterized in that that the Lewis Acid Halogen Compound is boron trifluoride is. Method according to one of the preceding claims, characterized characterized in that the work-up of the product phase is a distillative Workup includes. Method according to one of the preceding claims, characterized characterized in that after separation of the nitrile-rich phase treated the nitrile-poor product phase with an inorganic adsorbent. Method according to one of the preceding claims, characterized in that it is the oligomerization or polymerization of C ₃ -C _{2 0-} olefins in the acid-catalyzed reaction. Method according to claim 11, characterized in that that it is the acid catalyzed Reaction to the polymerization of an isobutene-containing hydrocarbon stream is. Method according to claim 12, characterized in that that the polymerization of the isobutene-containing hydrocarbon stream in the presence of boron trifluoride and at least one oxygen-containing Connection performed becomes. A method according to claim 13, characterized in that the oxygen-containing compound is selected from primary and secondary C ₁ -C ₅ alkanols and mixtures of at least one primary or secondary C ₁ -C ₅ alkanol with at least one further oxygen-containing compound which is C ₆ -C _{1 2} -alkanols and dialkyl ethers 5 to 12 C-atoms, is selected. Method according to claim 13, characterized in that that the polymerization of the isobutene-containing hydrocarbon stream in the presence of boron trichloride or titanium tetrachloride and at least a tertiary or allylic organic halogen compound. Process according to Claim 11, characterized in that the acid-catalyzed reaction is an oligomerization of C ₈ -C ₂₀ olefins. Process for the preparation of polyisobutene by Polymerization of an isobutene-containing hydrocarbon stream in Presence of catalytic amounts of a complex catalyst of boron trifluoride and at least one oxygen-containing compound, characterized that the reaction by addition of 0.5 to 10 mol at least an aliphatic nitrile per mole of Lewis acid halogen compound breaks off to the reaction mixture, a separation of the thus obtained Reaction mixture in a nitrile-rich phase and a nitrile-poor product phase causes the majority of the nitrile-rich phase from the nitrile-poor product phase separated and the product phase of further workup feeds, wherein the nitrile selected is under mononitriles having 2 or 3 carbon atoms and dinitriles with 3 to 6 carbon atoms.