WO2002045856A1

WO2002045856A1 - Method for removing aromatic hydroxy compounds from fluids

Info

Publication number: WO2002045856A1
Application number: PCT/EP2001/014341
Authority: WO
Inventors: Arno Lange; Hans Peter Rath
Original assignee: Basf Aktiengesellschaft
Priority date: 2000-12-07
Filing date: 2001-12-06
Publication date: 2002-06-13
Also published as: DE10060902A1; AU2002218323A1

Abstract

The invention relates to a method for removing aromatic hydroxy compounds from fluids that contain an aromatic hydroxy compound and at least one ring alkylation product. The method is characterized by contacting the fluid with an anion exchanger in the hydroxyl form, the aromatic hydroxy compound having a higher affinity to the anion exchanger than its ring alkylation products. The fluid from which the aromatic hydroxy compounds have been removed is then removed from the anion exchanger. The fluid used is for example a crude reaction mixture derived from the alkylation of aromatic hydroxy compounds.

Description

Process for the separation of aromatic hydroxy compounds from fluids

5

description

The present invention relates to a process for the separation of aromatic hydroxy compounds, in particular phenol, from ₁₀ fluids which contain the hydroxy compound and, if appropriate, core alkylation products thereof, and to a process for the preparation of core alkylation products of aromatic hydroxy compounds.

15 alkylphenols can be prepared by alkylation of phenol (cf. Ullmann's Encyclopedia of Industrial Chemistry, 5th edition, A19, p. 318ff). Since alkylphenols are usually more reactive than phenol, an excess of phenol is usually used for the selective production of monoalkylation products. The phenol

20 weft should be able to be removed extractively with water (cf. EP 0 628 022) or removed by distillation (cf. Ullmann's Encyclopedia of Industrial Chemistry, 5th edition, A19, p. 318ff). These processes have a number of disadvantages: Distillation is the energy generally used for evaporation

25 not recoverable. Contaminated wash water is produced during extraction with water, from which the phenol is difficult to remove / regenerate.

In wastewater treatment, hydrophobic organic resins - which, however, do not have any groups capable of ion exchange - are used for phenol extraction. Examples of these are the resins "Dowex Optipore L493" and "Dowex Optipore V493" and "Amberlite XAD-4" (cf. F.Mijangos, A.Navarro, M.Martin in "Progress in Ion Exchange", The Royal Society of Chemistry , 1997, page 332ff). The ^■ "Using partially pyrolyzed polymer resins for Phenoladsorption is proposed in US 4,040,990. The separation of mixtures of phenol and alkyl phenol, however, in this way not possible (F. Mijangos, A. Navarro, M. Martin in" Progress in Ion Exchange " , The Royal Society of Chemistry, 1997, page

40 340).

The present invention is therefore based on the object of a process for the separation of aromatic hydroxy compounds from fluids, in particular for the selective separation of aromatic

45 to provide hydroxy compounds from fluids which, in addition to the aromatic hydroxy compound, contain at least one core alkylation product thereof, which is simple and economical. Licher way is feasible.

Surprisingly, it has now been found that aromatic hydroxy compounds are bound to an anion exchanger in hydroxyl form and can thus be removed from a fluid to be purified. If aromatic hydroxy compound and kemalkylation products thereof are present side by side in the fluid, it has been found that the aromatic hydroxy compound binds to the anion exchanger with greater preference than its kemalkylation products.

The present invention therefore relates to a process for the separation of aromatic hydroxy compounds from fluids which contain an aromatic hydroxy compound and at least one core alkylation product thereof, in which the fluid is brought into contact with an anion exchanger in hydroxyl form, the aromatic hydroxy compound having greater preference is bound to the anion exchanger as their Ke alkylation products, and separates the fluid depleted in aromatic hydroxy compound from the anion exchanger.

In a second aspect, the invention relates to a process for the preparation of core alkylation products of aromatic hydroxy compounds, in which an aromatic hydroxy compound with a substantially monounsaturated C ₃ - to C ₄₀ o-olefin in the presence of an alkylation catalyst and a diluent to obtain a fluid which contains the aromatic hydroxy compounds and at least one core alkylation product thereof, and the fluid for separating the unreacted aromatic hydroxy compound and / or at least part of the alkylation catalyst in contact with an anion exchanger in hydroxyl form, the aromatic hydroxy compound and / or the alkylation catalyst greater preference is bound to the anion exchanger than the core alkylation products, and the fluid depleted in aromatic hydroxy compound and / or alkylation catalyst is separated from the anion exchanger.

In a further aspect, the invention relates to a process for the separation of aromatic hydroxy compounds from fluids which contain an aromatic hydroxy compound, in which the fluid is brought into contact with an anion exchanger in hydroxyl form, the aromatic hydroxy compound being at least partially bound to the anion exchanger , and the fluid depleted in aromatic hydroxy compound from the anion exchange shear separates.

Mono- are mononuclear or polynuclear aromatic compounds understood that droxylgruppe directly on the aromatic ring have at least one hybrid ^{■ *} * The term "aromatic hydroxy compound", in particular phenol, the isomeric cresols, halogenated phenols such as 2-chlorophenol and 3-bromophenol, nitrophenols, Alkanoylphenole such as 2-acetylphenol, phenol aldehydes such as salicylaldehyde, nitrile-substituted phenols such as 2- or 4-hydroxybenzonitrile, carboxy-substituted phenols such as salicylic acid or 4-hydroxybenzoic acid esters, 1- or 2-naphthol. A "Kernalkylierungsprodukt an aromatic hydroxy compound" means a compound that, upstream from the underlying aromatic hydroxy compound by multiple ownership of at least one alkyl group on the aromatic ring 5 preferably at least one Ci to C ₀₀ -alkyl radical, in particular of at least one C ₃ - to C4oo- Alkylrestes, differs. Exemplary alkyl radicals are methyl, ethyl, n-propyl, sec-propyl, isopropyl, n-butyl, iso-butyl, sec-butyl, ter-butyl, n-pentyl, n -Hexyl, octyl, decyl, undecyl and dodecyl radicals, and also 5-, 6- or 7-membered carbocyclic alkyl radicals. The alkyl radicals mentioned can in turn have substituents, such as. B. alkoxy substituents.

In certain embodiments, the alkyl radical 5 is one which is derived from oligomers or (co) polymers of lower alkenes, such as. B. ethene, propene, 1-butene, isobutene, 1-pentene, 2-methylbutene, 1-hexene, 2-methylpentene, 3-methylpentene, 4-methylpentene, the isomeric hexenes, heptenes, octenes, nonenes, decenes, Undecenes or dodecenes. Preferred examples are polypropenyl, polybutenyl or polyisobutenyl radicals.

In a preferred embodiment, the alkyl radical is an essentially homopolymeric polyisobutenyl radical, in particular one which is derived from a polyisobutene with a number average molecular weight of 200 to 5000. Such polyisobutenes are for example from Günther, Maenz and. Stadermann in Ang. Macrom. Che. 234, 71 (1996).

Presumably, the alkylation product of the aromatic hydroxy compound binds to the anion exchanger with less preference, the aromatic hydroxy compound on which it is based, because the acidity of the hydroxyl group is reduced by the electronic effect of the additional alkyl radical. In addition, 5 is often the affinity of the alkylation product for mobile

Fluid phase higher than that of the aromatic hydroxy compound, especially with non-aqueous fluids.

The fluid can be an aqueous or non-aqueous fluid. Non-aqueous fluids comprise an organic solu- ⁵ tration or diluent, especially aliphatic hydrocarbons, eg. B. pentane, hexane, heptane, cyclohexane or aromatic hydrocarbons such as benzene, toluene, ethylbenzene or the isomeric xylenes and mixtures thereof. Such mixtures are commercially available e.g. B. as "kerosene", "petroleum ether", "Solvesso"

^{• ■} -0 or "Aromatics 150" available. The hydrocarbons can also be halogenated. Non-limiting examples of these are methylene chloride, chloroform, 1,1, 1-trichloroethane, chlorobenzene or perfluoroalkanes. In many cases, non-aqueous fluids are crude reaction mixtures, such as those used in the

15 Alkylation of aromatic hydroxy compounds can be obtained in an organic solvent.

For a non-limiting description and listing of suitable anion exchangers, see Ullmann's Encyclopedia of

20 Industrial Chemistry, 5th edition, A14, pp. 393ff. Other useful basic anion exchangers are, for example, the resins Amberlite IRA-400, IRA-402, IRA-904, IRA-92, IRA-93 and Duolite A-109 from Rohm & Haas, Dowex 66 and Dowex II from Dow Chemical and Purolite A-600, A-400, A-300, A-850 and A-87 and

25 the Lewatit types from Bayer AG. The anion exchanger is selected with a pre-test so that it does not swell or only swells slightly when it comes into contact with the fluid. As a rule, highly crosslinked anion exchangers are preferred. The hydroxyl form of the anion exchanger can be treated by treatment with a solution of a common base, such as

30 sodium hydroxide or potassium hydroxide. In general, aqueous solutions are preferred because of their easy availability.

35 The fluid is brought into contact with the anion exchanger in a conventional manner, for example in a reaction vessel with stirring or in a cascade of reaction vessels. However, the fluid is preferably passed over a bed of the anion exchanger. The bed of the anion exchanger is suitable

40 i ⁿ a column arranged. The fluid is expediently passed over the bed in the direction of gravity, but the reverse flow direction can also be advantageous in individual cases.

45 The temperature at which the treatment is carried out is not critical. With regard to the fragility of the ion exchangers, excessively high temperatures will be avoided. In general operating at a temperature in the range of 0 ° C to about 70 ° C, preferably 20 to 40 ° C.

The quantitative ratio of fluid and anion exchanger depends on the amount of aromatic hydroxy compound to be removed. One skilled in the art can easily determine the appropriate amount by tracking the separation effect, e.g. B. by sampling the fluid running off the bed of the anion exchanger. It is found that the concentration of aromatic

^■ --0 Hydroxy compound in the flowing fluid increases, ie the separation effect becomes worse and the aromatic hydroxy compound is before "breaking through", the treatment is stopped and the anion exchanger is regenerated. The regeneration is generally carried out by treatment with a solution of a base, such as sodium hydroxide or potassium hydroxide.

The process according to the invention makes it possible to treat fluids which are up to about 500 mol%, in particular up to 300 mol% and generally 1 to 100 mol% of aromatic hydroxy compound

20 moved to the core alkylation products. In general, degrees of depletion of aromatic hydroxy compound of 50 to 100 mol%, in particular 90 to 99 mol%, are achieved.

25 In particular, if the fluid to be treated is a crude reaction mixture, as is obtained in the alkylation of aromatic hydroxy compounds with an alkyl halide or olefin, the fluid generally contains an alkylation catalyst and, if appropriate, adducts, reaction products.

30 products and / or deactivation products thereof. Exemplary alkylation catalysts are protonic acids, sulfuric acid, phosphoric acid and organic sulfonic acids, e.g. B. trifluoromethanesulfonic acid, Lewis acids, such as aluminum trihalides, for. As aluminum trichloride or aluminum tribromide, boron trihalides, for. B. boron

3 trifluoride and boron trichloride, tin halides, e.g. B. tin tetrachloride, titanium halides, e.g. B. titanium tetrabromide and titanium tetrachloride; and iron halides, e.g. B. iron trichloride and iron tribromide or adducts of Lewis acids with electron donors, such as alcohols, in particular Ci-Cg-alkanols or phenols, or

40 ethers. When treating the fluid according to the invention with the anion exchanger, the alkylation catalyst or its deactivation products are advantageously also removed.

The following examples illustrate the invention in more detail. example 1

a) separation

⁵ A solution containing 0.5 moles of phenol; 0.5 mol of 4-polyisobutene phenol (M _{n of} the polyisobutene residue: 1000), 50 g of toluene and 300 ml of kerosene is placed on a column which is filled with 200 g of "Serdolit Blue" (Serva Elektrophoresis GmbH, Heidelberg) in hydroxyl form, given. It is rinsed with 200 ml of kerosene and the agreed ^•• "O temperate fractions are concentrated by rotary evaporation mbar on a rotary evaporator at 120 ° C and 5. FIG.

549 g of oil, which according to 1-H NMR is 4-polyisobutene phenol and contains less than 0.5 mol% (about 0.04% by weight) of phenol.

15 b) Regeneration of the ion exchanger

500 ml of a 10% solution of NaOH in water are added to the column, followed by rinsing with 500 ml of water. The 0 water phases are combined, acidified with hydrochloric acid and extracted with diethyl ether. The ether extracts are concentrated on a rotary evaporator at 40 ° C./150 mbar: 43 g of phenol

5

Example 2

Each 800 ml of a hexane solution containing 6 g / 1 BF ₃ -phenol complex are placed on an ion exchange column which is filled with 100 g of exchange resin. The eluate is extracted with 250 ml of 25% ammonia solution and the fluorine content of the ammonia solution is determined.

For comparison, 800 ml of the hexane solution are treated directly with 250 ml of 25% ammonia solution. 5

Ion exchange resin fluorine (mg / 1) Serdolite Blue 11

Amberlite IRA 402 23 0 comparison 4800

This example shows that the process according to the invention can also be used to separate alkylation catalysts from the fluid to be treated. 5

Claims

claims

1. A process for the separation of aromatic hydroxy compounds from fluids containing an aromatic hydroxy compound and at least one core alkylation product thereof, in which the fluid is brought into contact with an anion exchanger in hydroxyl form, the aromatic hydroxy compound being bound to the anion exchanger with greater preference than their core alkylation products, and the fluid depleted in aromatic hydroxy compound is separated from the anion exchanger.

2. The method of claim 1, wherein the fluid is a non-aqueous fluid.

3. The method according to claim 1 or 2, wherein one uses a strongly basic anion exchanger.

4. The method according to any one of the preceding claims, wherein the aromatic hydroxy compound is phenol.

5. The method according to any one of the preceding claims, wherein the core alkylation products of the aromatic hydroxy compound differ from the aromatic hydroxy compound in that they possess at least one C 1 -C ₄ oo-alkyl group.

6. The method according to claim 5, wherein the alkyl radical is a substantially homopoly eren polyisobutenyl radical.

7. The method according to any one of the preceding claims, wherein the fluid is passed over a bed of the anion exchanger.

8. The method according to any one of the preceding claims, in which the anion exchanger is regenerated by treatment with a solution of a base.

9. A process for the preparation of core alkylation products of aromatic hydroxy compounds, in which an aromatic hydroxy compound is reacted with a substantially monounsaturated C ₃ to C ₄ o-olefin in the presence of an alkylation catalyst and a diluent to give a fluid which gives the aromatic hydroxy compounds and contains at least one core alkylation product thereof, and the fluid for separating the unreacted aromatic hydroxy compound and / or at least a portion of the alkylation catalyst in contact with an anion exchanger in hydroxyl form, the aromatic hydroxy compound and / or the alkylation catalyst having greater preference to the Anion exchanger is bound as the nuclear alkylation products, and the fluid depleted in aromatic hydroxy compound and / or alkylation catalyst separates from the anion exchanger.

10. Process for the separation of aromatic hydroxy compounds from fluids containing an aromatic hydroxy compound, in which the fluid is mixed with an anion exchanger

Brings hydroxyl form in contact, wherein the aromatic hydroxy compound is at least partially bound to the anion exchanger, and the fluid depleted in aromatic hydroxy compound separates from the anion exchanger.