Removal of polyethylene glycols from ethoxylates

Abstract

The invention relates to a process for removing oligo- and polyethylene glycols from ethoxylated alkanols.

Description

[0001] Separation of polyethylene glycols from ethoxylates

[0002] Description

[0003] The present invention relates to a process for separating oligo- and polyethylene glycols from ethoxylated alkanols.

[0004] The ethoxylation of alkanols is usually carried out industrially by reacting the alkanols with ethylene oxide under the catalysis of bases such as sodium or potassium hydroxide. Water is introduced into the reaction either through these bases or as an accompanying component of the alkanol, leading to the formation of oligoglycols and polyethylene glycols. These oligoglycols and polyethylene glycols exhibit higher hydrophilicity than the actual target products.

[0005] In many applications, the presence of oligo- and polyethylene glycols is not detrimental, since the ethoxylated alkanols are already combined with polyethylene glycols in applications such as surfactants or cleaning and washing agents.

[0006] On the one hand, the diethylene glycol contained in oligoethylene glycols is a starting material for the formation of the toxicologically problematic dioxane; on the other hand, the hydrophilic higher ethylene glycols in the ethoxylated alkanols lead to turbidity. Furthermore, especially in the case of low-ethoxylated alkanols, where the hydrophobic character of the alkanol is pronounced, the properties of the ethoxylated alkanol are significantly impaired by the presence of the hydrophilic polyethylene glycols, as this affects the hydrophilicity-hydrophobicity balance of the product.

[0007] The object of the present invention was to provide a process for the removal of oligo- and polyethylene glycols from one- to three-fold ethoxylated Cs-Cu alkanols, especially those obtained from base-catalyzed ethoxylation.

[0008] DE 828839 describes the separation of polyglycols from reaction mixtures of the alkoxylation of alcohols, acids, phenols, alkylphenols, and naphthols with 20 to 400% water at elevated temperature. The explicitly disclosed examples use 50 to 200 wt% water based on the alkoxylate, where the alkoxylates are structurally very different, but ethoxylated alcohols are not explicitly disclosed.

[0009] WO 2021 / 262439 A2 describes the extraction of polyethylene glycols from fatty alcohol ethoxylates, using at least 50 wt% water for the extraction. Such high amounts of water have the disadvantage that large quantities of the desired hydrophilic product also pass into the aqueous phase and are thus lost.

[0010] Instead of extraction with water, WO 2021 / 262439 A2 also proposes extraction with electrolyte-containing solutions, for example aqueous sodium chloride solution, which facilitates phase separation.

[0011] However, this has the disadvantage that traces of the electrolyte pass into the organic phase of the fatty alcohol ethoxylate, which can lead to corrosion in later applications, for example with chlorides.

[0012] EP 43963 A1 describes the ethoxylation of primary monoalcohols with Friedel-Crafts or acidic catalysts followed by basic washing. The washing serves to remove the acidic catalyst; polyethylene glycols are explicitly left in the reaction mixture.

[0013] EP 1015404 B1 describes the production of random polymers of fatty alcohols with ethylene oxide and propylene oxide. It notes that polyethylene glycols are formed as byproducts. These could, in principle, be removed by extraction with suitable solvents such as water, but this requires a further process step that is very time-consuming and not universally applicable.

[0014] Extraction therefore has disadvantages and is not necessarily transferable from one product to another.

[0015] The problem is solved by a process for separating oligo- and polyethylene glycols of the formula HO-[-CH2-CH2-O] n -H wherein n is a rational number of at least 2, preferably of 2 to 30 and particularly preferably of 2 to 20 from ethoxylated alkanols of the formula

[0016] R 1 -O-[-CH2-CH2-O-] m -H wherein

[0017] R 1straight-chain or branched, preferably straight-chain Cs-Cu alkyl, preferably Cs-Cia alkyl, particularly preferably C9-Ci3 alkyl, and most preferably C9-C1i alkyl, and m is a rational number from 1 to 3, in which (i) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols is mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase,

[0018] (ii) allows the phases to separate at a temperature of 30 to 90 °C,

[0019] (ill) separates the organic from the aqueous phase and

[0020] (iv) optionally reducing the water content of the organic phase, characterized in that the extraction is carried out in the presence of a gas atmosphere in which the proportion of oxygen is not more than 10 vol%, preferably not more than 8, particularly preferably not more than 6, most particularly preferably not more than 5, in particular not more than 2 and especially not more than 1 vol%.

[0021] A preferred embodiment of the present invention consists in reducing the dissolved oxygen content in the ethoxylated alkanol and / or in the water before use in the extraction, particularly before heating to the temperature at which the extraction is carried out.

[0022] Another preferred embodiment of the present invention consists in reducing the dissolved oxygen content in the ethoxylated alkanol before use in the extraction to no more than 25% of the possible saturation at the storage temperature, preferably to no more than 20%, particularly preferably to no more than 15%, and most preferably to no more than 10%. The storage temperature is the ambient temperature at which the ethoxylated alkanol is stored, preferably a temperature of 20 °C. Unless otherwise specified, the determination of dissolved oxygen is carried out as described below in the experimental section.

[0023] The invention is based on the observation that oligo- and polyethylene glycols are formed from the ethoxylated alkanol under thermal stress in the presence of oxygen.

[0024] The present invention has the advantage that it keeps the losses of the ethoxylated alkanol as the value product low and at the same time allows both oligo- and polyethylene glycols as well as (earth)alkali metal ions to be removed from the catalyst used for the ethoxylation if the ethoxylation of the alkanol was carried out in the presence of at least one basic salt.

[0025] By using water instead of, for example, saline solution, the introduction of chloride into the valuable product is avoided, so that the product obtained in this way is also suitable for applications in which corrosion or combustion processes play a role.

[0026] Accordingly, a further object of the present invention is a process for the production of ethoxylated

[0027] Alkanols of formula R 1 -O-[-CH2-CH2-O-] m -H wherein

[0028] R 1straight-chain or branched Cs-Cu alkyl, preferably Cs-C alkyl, particularly preferably Cg-C alkyl, and most preferably Cg-Cn alkyl and m a rational number of 1 to 3 with a reduced content of oligo- and polyethylene glycols of the formula

[0029] HO-[-CH2-CH2-O] n -H wherein n is a rational number of at least 2, preferably from 2 to 30 and particularly preferably from 2 to 20, and a simultaneously reduced content of (earth)alkali metal ions, characterized in that one

[0030] (I) an alkanol R 1 -OH reacts with at least m equivalents of ethylene oxide in the presence of at least one basic salt of at least one (earth)alkali metal and in the presence of water at a temperature of 20 to 200 °C to obtain a mixture of oligo- and polyethylene glycols and ethoxylated alkanols and

[0031] (II) subjects the mixture thus obtained to a purification process in which

[0032] (I) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase,

[0033] (II) allows the phases to separate at a temperature of 30 to 90 °C,

[0034] (ill) separates the organic from the aqueous phase and

[0035] (iv) optionally reducing the water content of the organic phase, characterized in that the extraction is carried out in the presence of a gas atmosphere in which the proportion of oxygen is not more than 10 vol%, preferably not more than 8, particularly preferably not more than 6, most particularly preferably not more than 5, in particular not more than 2 and especially not more than 1 vol%.

[0036] Another object of the present invention is a method for separating oligo- and polyethylene glycols of the formula

[0037] HO-[-CH2-CH2-O] n -H wherein n is a rational number of at least 2, preferably of 2 to 30 and particularly preferably of 2 to 20 from ethoxylated alkanols of the formula

[0038] R 1 -O-[-CH2-CH2-O-] m -H wherein

[0039] R 1straight-chain or branched, preferably straight-chain Cs-Cu alkyl, preferably Cs-C alkyl, particularly preferably Cg-C alkyl, and most preferably C9-C1 i-alkyl, and m is a rational number from 1 to 3, wherein one

[0040] (i) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase,

[0041] (ii) allows the phases to separate at a temperature of 30 to 90 °C,

[0042] (ill) separates the organic from the aqueous phase,

[0043] (iv) optionally reduces the water content of the organic phase, characterized in that, prior to extraction, the dissolved oxygen content in the ethoxylated alkanol is reduced to no more than 25% of the saturation at storage temperature, preferably to the saturation at 20 °C, preferably to no more than 20%, particularly preferably to no more than 15% and most particularly preferably to no more than 10%.

[0044] Another object of the present invention is a process for the production of ethoxylated alkanols of the formula

[0045] R 1 -O-[-CH2-CH2-O-] m -H wherein

[0046] R 1 straight-chain or branched Cs-Cu-alkyl, preferably Cs-Cn-alkyl, particularly preferably Cg-Cn-alkyl, and most preferably Cg-Cn-alkyl and m a rational number of 1 to 3 with a reduced content of oligo- and polyethylene glycols of the formula HO-[-CH2-CH2-O] n-H wherein n is a rational number of at least 2, preferably from 2 to 30 and particularly preferably from 2 to 20, and a simultaneously reduced content of (earth)alkali metal ions, characterized in that one

[0047] (I) an alkanol R 1 -OH reacts with at least m equivalents of ethylene oxide in the presence of at least one basic salt of at least one (earth)alkali metal and in the presence of water at a temperature of 20 to 200 °C to obtain a mixture of oligo- and polyethylene glycols and ethoxylated alkanols and

[0048] (II) subjects the mixture thus obtained to a purification process in which

[0049] (i) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase,

[0050] (II) allows the phases to separate at a temperature of 30 to 90 °C,

[0051] (ill) separates the organic from the aqueous phase and

[0052] (iv) optionally reduces the water content of the organic phase, characterized in that, prior to extraction, the dissolved oxygen content in the ethoxylated alkanol is reduced to no more than 25% of the saturation at storage temperature, preferably to the saturation at 20 °C, preferably to no more than 20%, particularly preferably to no more than 15% and most particularly preferably to no more than 10%.

[0053] The ethoxylated alkanols fulfill the formula

[0054] R 1 -O-[-CH2-CH2-O-] m -H wherein

[0055] R 1 straight-chain or branched, preferably straight-chain Cs-Cu alkyl, preferably Cs-C₆ alkyl, particularly preferably C₁-C₆³ alkyl, and most preferably C₁-C₆³ alkyl, and m is a rational number from 1 to 3. Examples of the underlying alkanols R 1 OH are n-octanol (octyl alcohol, caprylic alcohol), 2-ethylhexanol, nonyl alcohol (pelargonyl alcohol), iso-nonanol, n-decanol, 2-propylheptanol, decyl alcohol (capric alcohol), undecyl alcohol, dodecyl alcohol (lauryl alcohol), tridecyl alcohol and tetradecyl alcohol (myristyl alcohol).

[0056] In a preferred embodiment, these are pure substances such as 2-ethylhexanol or 2-propyl heptanol.

[0057] In another embodiment, the underlying alkanol R can be1 OH refers to a mixture of different alkanols, which on average have 8 to 14, preferably 9 to 11, carbon atoms. Since these are mixtures, the number of carbon atoms can also take on non-integer values.

[0058] Examples of such mixtures are mixtures of fatty alcohols, e.g., those obtained from coconut oil. Such mixtures are predominantly composed of Cs to Cie alkanols with even numbers of carbon atoms, typically 4.6–10.0 wt% Cs alkanol, 5.0–8.0 wt% Cw alkanol, 45.1–53.2 wt% Ci2 alkanol, 16.8–21.0 wt% Cu alkanol, and 7.5–10.2 wt% C2 alkanol.

[0059] In another embodiment, the alcohol R 1-OH to a mixture of alcohols having about 13 carbon atoms, particularly preferably to one obtained by hydroformylation from a C12 olefin mixture which in turn is obtained by oligomerization of an olefin mixture containing predominantly four carbon atoms hydrocarbons.

[0060] On average, this olefin mixture has 11 to 16 carbon atoms, preferably 11.1 to 12.9, particularly preferably 11.2 to 12.8, most preferably 11.5 to 12.5 and particularly 11.8 to 12.2. The alcohols obtained from it accordingly have one more carbon atom.

[0061] In a particularly preferred embodiment, this alcohol R 1 -OH exhibits an average degree of branching, measured as an ISO index, of 1.8 to 2.7.

[0062] Such mixtures are commercially available as tridecanols or iso-tridecanols.

[0063] Particularly preferred are mixtures of linear alcohols having 9, 10, and 11 carbon atoms. In a particularly preferred embodiment, the alkanol R is... 1 OH is a mixture of primary alcohols with the composition of 15-20 wt% C9, 40-45 wt% C10, and 35-40 wt% Cn alcohols, wherein the proportion of alcohols with 8 or fewer or with 12 or more carbon atoms is not more than 1 wt%. Particularly preferably, these are highly linear alkanols exhibiting a degree of branching, measured as an ISO index, of not more than 0.5, preferably not more than 0.3, particularly preferably not more than 0.2, and most preferably not more than 0.1. The average molecular weight of such an alcohol mixture is from 158 to 164 g / mol. The OH number is from 342 to 355 mg KOH / g.

[0064] The degree of ethoxylation m of the ethoxylated alkanols is a rational number from 1 to 3, preferably 1.5 to 3, particularly preferably 1.75 to 3, very preferably 1.75 to 2.75 and particularly 2 to 2.75.

[0065] The degree of ethoxylation m is an arithmetic mean, therefore m can also take on non-integer values.

[0066] The oligo- and polyethylene glycols of the formula HO-[-CH2-CH2-O] n -H are mostly formed as a byproduct during the ethoxylation of alkanols.

[0067] The degree of polymerization n is also a rational number of at least 2, preferably from 2 to 30, and particularly preferably from 2 to 20. Here too, it is an arithmetic mean; therefore, m can also take on non-integer values.

[0068] The proportion of oligoglycols and polyethylene glycols in the ethoxylated alkanols varies and is mostly dependent on the water content during the ethoxylation and the reaction conditions. Due to the low molecular weight of water, even small amounts of water are sufficient to result in comparatively high concentrations of oligoglycols and polyethylene glycols.

[0069] Sources of water include, in particular, the alkanol used and the base used as a catalyst. The base is usually used as an aqueous solution, and subsequent removal is either not entirely successful or uneconomical. Other possible sources include atmospheric humidity or traces of moisture in any protective gas used, contamination in the equipment, and a small amount of water in the ethylene oxide.

[0070] The content of oligo- and polyethylene glycols in the ethoxylated alkanols can generally be up to 5 wt%, preferably up to 3, particularly preferably up to 2.5, most preferably up to 2, particularly up to 1.5 and especially up to 1 wt%.

[0071] Different requirements are placed on the target value for the content of oligo- and polyethylene glycols for different applications, see below.

[0072] The reaction of alkanols with ethylene oxide usually proceeds under the catalysis of bases, mostly basic (earth)alkali metal salts. The (earth)alkali metal is usually sodium, potassium, magnesium, or calcium, preferably sodium or potassium, and particularly preferably potassium.

[0073] The anion of these basic salts is selected from the group consisting of hydroxide, oxide, carbonate, hydrogen carbonate, phosphate, hydrogen phosphate, dihydrogen phosphate, Ci-Cio alcoholate and Ci-Cio carboxylate, preferably hydroxide, oxide, carbonate or hydrogen carbonate, particularly preferably hydroxides.

[0074] Particularly preferred basic (earth)alkali metal salts are sodium hydroxide, sodium carbonate, sodium phosphate, sodium acetate, potassium hydroxide, potassium carbonate, potassium phosphate and potassium acetate; sodium hydroxide and potassium hydroxide are particularly preferred.

[0075] Furthermore, the Ci-Cio alcoholates are preferred, preferably Ci-C4 alcoholates, particularly preferably methanolates or ethanolates of the (earth) alkali metals, especially sodium or potassium.

[0076] In a preferred embodiment, the underlying alkanol R 1OH is converted to the corresponding (earth)alkali metal alkanoate prior to ethoxylation, for example by prior reaction with a -methoxide or -ethoxide or reaction with the metal in question, especially sodium or potassium.

[0077] Ethoxylation usually occurs when the alkanol R 1 OH and ethylene oxide are reacted in a molar ratio of at least 1 to m. A molar ratio of 1 to m to 1 to (1.5 x m) is particularly advantageous, especially 1 to m to 1 to (1.25 x m), and particularly 1 to m to 1 to (1.1 x m).

[0078] The reaction with ethylene oxide can be carried out at 50 to 200 °C. A temperature range of 100 to 180 °C is preferred, particularly 120 to 160 °C.

[0079] The process can be carried out at atmospheric pressure, under vacuum, and at elevated pressures, for example, at pressures from 0.8 to 50 bar (abs), particularly at pressures from 1 to 10 bar (abs). A slight overpressure up to 2 bar (abs) is especially advantageous.

[0080] The basic salt is used in amounts of 0.01 to 5% by weight based on the alkanol R. 1 OH is used, preferably 0.05 to 2 and particularly preferably 0.05 to 0.5 wt%.

[0081] Ethoxylation is preferably carried out under an inert gas cover, for example by nitrogen, argon, carbon dioxide or lean air, i.e. oxygen-depleted air, preferably nitrogen.

[0082] The inert gas may contain small amounts of molecular oxygen or nitrogen monoxide that are safe from a safety perspective, so that the explosion limit of the ethylene oxide is not exceeded, for example less than 5 vol%, preferably less than 2 vol%, particularly preferably less than 1 vol% and most preferably less than 0.5 vol%.

[0083] The process does not require the use of solvents. However, it is possible, though less preferred, to carry out the process in the presence of organic solvents such as aliphatic, cycloaliphatic, or aromatic hydrocarbons, ethers, acetals, ketones, esters, or cyclic carbonates.

[0084] If the basic salt is used as a solid, for example in powder form, a reaction carried out in suspension mode is advantageous, for example in one or more stirred reactors.

[0085] The basic salt can either remain in the reactor, for example it can be retained by a frit, filter or sieve, or it can be carried out with the reactor discharge and subsequently separated from the reaction mixture, for example by sedimentation, filtration, centrifugation or absorption, preferably by filtration, which may optionally be supported by a filtration aid such as Celite, aluminum oxide, silicates, silica gel or activated carbon.

[0086] The basic salt can be added to the alkanol in the form of an aqueous solution (usually around 50%), and then the water is removed under vacuum at elevated temperature until a certain water content (usually 1000 ppm) is reached. Ethylene oxide is then added to the resulting starter mixture at the appropriate reaction temperature.

[0087] Ethoxylation processes are generally described in M. lonescu: Chemistry and Technology of Polyols for Polyurethanes, Rapra Technology Limited, 2005, ISBN:1-85957-491-2.

[0088] The conversion can be carried out discontinuously, in the sense of a batch or semi-batch process, or continuously. It can be performed in a stirred reactor, tubular reactor, loop reactor, fixed-bed reactor, or fluidized-bed reactor.

[0089] It is also possible to connect several of the aforementioned reaction units in series. This allows the process to be operated in multiple stages. It is also possible to operate several reactors in parallel within a single process stage.

[0090] The heat of reaction can be dissipated, for example, via a reactor jacket, welded-on half-pipe coils or pipe coils, cooling pipes within the reactor, downstream or upstream heat exchangers, a total condenser in boiling mode, or any combination of these methods. In continuous operation, the reaction mixture is circulated. This is typically achieved by pumping the reaction mixture through an external circuit. A heat exchanger can also be integrated into this external circuit.

[0091] The heat of reaction can be dissipated, for example, via a reactor jacket, welded-on half-pipe coils or pipe coils, cooling pipes in the reactor, downstream or upstream heat exchangers, a total condenser in boiling mode, or any combination of the aforementioned variants.

[0092] The finished ethoxylated alkanol is freed from residual ethylene oxide by applying a vacuum and, optionally, a stripping gas such as nitrogen, air, nitrogen-air mixtures, or steam. The ethoxylated alkanol is then purified and freed from volatile impurities, preferably by stripping in a vessel or column.

[0093] Ethoxylated alkanols, especially those obtained by the process described above, contain oligo- and polyethylene glycols, depending on the water content of the starting materials, which can be up to 5 wt% or more.

[0094] If the preparation was carried out in the presence of a basic salt of an (earth)alkali metal, the ethoxylated alkanol may also contain traces of this (earth)alkali metal, for example in amounts up to 0.5 wt%, preferably up to 0.3 wt%. Particularly preferably up to 0.2 wt% and especially up to 0.1 wt%.

[0095] Depending on the intended later use for the ethoxylated alkanol, the content of oligo- and polyethylene glycols and / or (earth)alkali metals may have a disruptive effect.

[0096] This is particularly the case with hydrophilic oligo- and polyethylene glycols when the hydrophobicity of the comparatively relatively hydrophobic ethoxylated alkanols is important in their application, for example in application in a hydrophobic medium, such as the distribution or dispersion of water in this hydrophobic medium in the sense of a w / o emulsion (water in oil).

[0097] Specifically, diethylene glycol, in the form of oligo- and polyethylene glycol, is a starting material for the formation of dioxane, which should be separated from the product for toxicological reasons. Dioxane is formed from diethylene glycol particularly under acidic conditions, for example, during the production of polyether sulfates from ethoxylated alkanols. Therefore, the separation of the oligo- and polyethylene glycols according to the invention is preferred when the ethoxylated alkanol is exposed to acidic conditions in a subsequent use or derivatization, and especially when the ethoxylated alkanol is later to be converted into the corresponding polyether sulfate. It has been observed that the content of oligo- and polyethylene glycol increases during storage of ethoxylated alkanols, particularly when stored in an atmospheric environment.This can be counteracted by storing the product under an oxygen-depleted gas atmosphere and / or by reducing the oxygen content in the ethoxylated alkanol before storage.

[0098] The presence of (earth)alkali metals should also be kept as low as possible, especially in applications in a hydrophobic medium, as these cations tend to precipitate out of the hydrophobic medium and can thus lead to deposits.

[0099] According to the invention, the mixture of oligo- and polyethylene glycols and ethoxylated alkanols is subjected to a purification process in which one

[0100] (I) the mixture is mixed with a specific amount of water based on the organic phase,

[0101] (II) allows the organic and aqueous phases to separate,

[0102] (ill) separates the organic from the aqueous phase and

[0103] (iv) optionally reduces the water content of the organic phase.

[0104] According to the invention, the extraction is carried out in the presence of a gas atmosphere in which the proportion of oxygen is no more than 10 vol%, preferably no more than 8, particularly preferably no more than 6, most preferably no more than 5, in particular no more than 2 and specifically no more than 1 vol%.

[0105] The gas atmosphere can be oxygen-depleted air (lean air) or a gas inert under the extraction conditions, preferably nitrogen, argon or carbon dioxide, particularly preferably nitrogen.

[0106] For this purpose, at least one of steps (I), (II) or (ill) is carried out in the presence of an oxygen-deficient gas atmosphere, preferably at least one of steps (ii) or (ill), particularly preferably at least step (ii), most preferably at least steps (ii) and (ill) and in particular all three steps (i), (ii) and (ill).

[0107] In a preferred embodiment, such steps are carried out in the presence of an oxygen-deficient gas atmosphere in which the temperature of the ethoxylated alkanol reaches or exceeds at least 50 °C.

[0108] A preferred embodiment of the present invention consists in reducing the dissolved oxygen content in the ethoxylated alkanol and / or in the water before use in the extraction, preferably at least in the ethoxylated alkanol, and particularly preferably in both the ethoxylated alkanol and the water.

[0109] In a particularly preferred embodiment, this reduction of the dissolved oxygen content takes place before heating to the temperature at which the extraction is carried out. The reduction of the dissolved oxygen content can be achieved, for example, by applying a vacuum and / or passing a stripping gas, preferably a low-oxygen gas or water vapor, preferably lean air, nitrogen, argon, or water vapor, most preferably nitrogen or water vapor, and most preferably nitrogen. Preferably, a stripping gas is passed through the respective medium, optionally assisted by applying a vacuum.

[0110] The stripping process should be carried out for at least 1 to 24 hours, preferably 1.5 to 20 hours, and most preferably 2 to 16 hours.

[0111] In this process, 0.1 to 20 times the volume of stripping gas relative to the volume of the ethoxylated alkanols is passed through the ethoxylated alkanol per hour, preferably 0.2 to 15 times, particularly preferably 0.5 to 10 times.

[0112] The stripping gas can be introduced, for example, through submerged inlet pipes, nozzles, frits, or pipes with openings for the stripping gas located in the liquid.

[0113] In the case of water, the reduction of the dissolved oxygen content can also be achieved by heating to a temperature of at least 50°C, preferably at least 60°C, particularly preferably at least 70°C, and most preferably at least 80°C. At 80°C, water under normal pressure has an oxygen content of less than 1 ppm (M. Ros, GD Zupancic, Acta Chim. Slov. 2002, 49, 931-943). Most preferably, the water is heated to the temperature at which step (I) is carried out before contact with the ethoxylated alkanol.

[0114] In a preferred embodiment, the dissolved oxygen content in the mixture of ethoxylated alkanol and oligo- and polyethylene glycols is reduced by at least 20% compared to the saturated oxygen content of the mixture at 20 °C and normal pressure before use in the extraction process, preferably by at least 25%, particularly preferably by at least 30%, most preferably by at least 40%, particularly by at least 50%, and especially by at least 60%. It may be advantageous to reduce the oxygen content by at least 70%, at least 80%, or even at least 90%.

[0115] Since the solubility of oxygen in the mixture of ethoxylated alkanol and oligo- and polyethylene glycols depends on the lipophilicity or hydrophilicity of the mixture, i.e., especially on the number of carbon atoms in the alkanol, the degree of ethoxylation, and the content of oligo- and polyethylene glycols, it is difficult to specify an absolute content of dissolved oxygen.

[0116] It has proven advantageous that the dissolved oxygen content in the mixture of ethoxylated alkanol and oligo- and polyethylene glycols before use in the extraction is not more than 100 ppm by weight, preferably not more than 90, particularly preferably not more than 80, most preferably not more than 70, in particular not more than 60 and especially not more than 50 ppm by weight.

[0117] In the specific case of 2.5-fold ethoxylated Cg-Cn alkanols (R 1 = C9-C1 i-Alkyl, m = 2,5) it has proven advantageous to reduce the dissolved oxygen content in the ethoxylated alkanol to no more than 6 ppm, preferably no more than 5, particularly preferably no more than 4, most preferably no more than 3 and particularly preferably no more than 2 ppm.

[0118] Accordingly, a further object of the present invention is a process for the preparation of ethoxylated alkanols of the formula

[0119] R 1 -O-[-CH2-CH2-O-] m -H wherein

[0120] R 1 straight-chain or branched C9-C11 alkyl and m a rational number of 2 to 3, preferably of about 2.5, with a reduced content of oligo- and polyethylene glycols of the formula HO-[-CH2-CH2-O] n -H wherein n is a rational number of at least 2, preferably from 2 to 30 and particularly preferably from 2 to 20, and a simultaneously reduced content of (earth)alkali metal ions, characterized in that one

[0121] (I) an alkanol R 1-OH reacts with at least m equivalents of ethylene oxide in the presence of at least one basic salt of at least one (earth)alkali metal and in the presence of water at a temperature of 20 to 200 °C to obtain a mixture of oligo- and polyethylene glycols and ethoxylated alkanols and

[0122] (II) subjects the mixture thus obtained to a purification process in which

[0123] (I) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase,

[0124] (II) allows the phases to separate at a temperature of 30 to 90 °C,

[0125] (ill) separates the organic phase from the aqueous phase and (iv) optionally reduces the water content of the organic phase, characterized in that, prior to extraction, the dissolved oxygen content in the ethoxylated alkanol is reduced to no more than 6 ppm, preferably no more than 5, particularly preferably no more than 4, most preferably no more than 3 and particularly preferably no more than 2 ppm.

[0126] In step (i) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols is mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times the volume (v / v) of water per 1 volume of organic phase.

[0127] The temperature during mixing ranges from ambient temperature to 90 °C, preferably from 20 to 85 °C, particularly preferably from 35 to 80 °C, most preferably from 40 to 80 °C and particularly from 45 to 75 °C.

[0128] It is also possible to work at higher temperatures, for example at 95 °C or, with the application of overpressure, even at temperatures above 100 °C; however, this is less preferred because, on the one hand, it is more complex in terms of equipment, and on the other hand, the stability of the product can be impaired by these high temperatures.

[0129] The temperature can remain the same or increase during mixing.

[0130] The duration of the mixing is less relevant; it can range from 1 minute to 8 hours, preferably from 5 minutes to 4 hours, particularly preferably from 10 minutes to 2 hours, and most preferably from 15 to 90 minutes.

[0131] According to the invention, the essential element in the mixing step (i) is the amount of water, which is 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase.

[0132] Smaller volumes of water are insufficient to effectively remove the hydrophilic components in an economically viable number of washing steps, while larger quantities of water remove too much valuable product from the mixture.

[0133] It is possible to carry out the extraction according to the invention with larger quantities of water, for example, more than 2 to 10 times, preferably more than 2 to 5 times, the volume, for example, when the removal of polyethylene glycols is the primary objective and losses of fatty alcohol ethoxylates are acceptable. The water used according to the present invention should preferably be ion-free, i.e., water with a neutral pH value that contains essentially no ions other than the hydroxide and hydronium ions resulting from the autoprotolysis of water at the respective temperature.

[0134] The electrical conductivity (determined according to ASTM D 1125) at 25 °C of the ion-free water used should preferably not exceed 5 piS / cm, more preferably not exceed 3, more preferably not exceed 2 and in particular not exceed 1 piS / cm.

[0135] The ion-free water used can be pure distilled or double distilled water, or water that has been deionized, for example by ion exchange, preferably by ion exchange of at least the cations, and particularly preferably by ion exchange of both the cations and the anions.

[0136] The mixing of the organic phase with the water generally occurs through the input of energy via shear energy. This can be achieved, for example, in dynamic mixing devices, i.e., by mixing using a stirrer or by pumping (natural or forced circulation) or pumping with static mixing devices such as static mixers or nozzles in the pumping circuit, by static mixing devices such as static mixers, nozzles, orifices, Y- or T-pieces in the inlet of the mixing tank, or by dynamic mixing devices such as mixing pumps or stirred tanks.

[0137] In step (ii), the organic and aqueous phases are separated at elevated temperature, exploiting the fact that the systems according to the invention, consisting of oligo- and polyethylene glycols and ethoxylated alkanols, have an upper separation temperature (OET) or form an emulsion that separates upon increasing temperature. In the latter case, it is possible that the emulsions are formed by the presence of ethoxylated alkanols with a value for m > 3, since such highly ethoxylated alkanols, which are present in small proportions in the ethoxylated alkanols due to production processes, can act as emulsifiers.

[0138] The temperature in step (ii) is generally selected from 30 to 90 °C, preferably from 35 to 85 °C, particularly preferably from 40 to 85 °C and most particularly preferably from 45 to 80 °C.

[0139] The duration of the separation process can range from 10 minutes to 8 hours, preferably from 15 minutes to 4 hours, particularly preferably from 30 minutes to 3 hours and most preferably from 45 minutes to 4 hours.

[0140] At high concentrations of oligoglycols and polyethylene glycols in the system, these can act as solubility enhancers between the organic and aqueous phases, which, through the formation of mixed phases, makes demixing more difficult and delays it. In this case, the addition of an organic solvent can accelerate demixing, which, depending on the intended use, can later remain in the ethoxylated alkanol or be separated from it. The use of emulsion breakers or phase separation aids to improve or accelerate demixing or to stabilize the phase boundary is conceivable, although less preferred, since these usually remain in the product. Such aids are not preferably used in the process according to the invention.

[0141] In step (ill) the organic phase is separated from the aqueous phase.

[0142] This separation usually takes place at the same temperature as in step (ii), but it can exceptionally be down to 20, preferably down to 15 and particularly preferably down to 10 °C lower.

[0143] Steps (i) to (ill) can be carried out, for example, in a mixing vessel or in other conventional apparatus, e.g., in a column or mixer-settler apparatus.

[0144] From a process engineering perspective, all known extraction and washing processes and apparatus can be used for these steps in the described procedure, e.g., those described in Ullmann's Encyclopedia of Industrial Chemistry, 6th ed, 1999 Electronic Release, Chapter: Liquid - Liquid Extraction - Apparatus. For example, these can be single-stage or multi-stage extractions, preferably single-stage, as well as those operating in co-current or counter-current mode, preferably counter-current mode.

[0145] Preferably, sieve tray or packed columns, stirred tanks or mixer-settler apparatuses, as well as pulsed columns or those with rotating internals are used; stirred tanks and mixer-settler apparatuses are particularly preferred.

[0146] Steps (i) to (ill) in the method according to the invention can be carried out one or more times, preferably one to ten times, particularly preferably one to eight times and most preferably one to six times.

[0147] More frequent execution of steps (i) to (ill) is of course possible, but is mostly uneconomical and leads to increased losses of ethoxylated alkanols as a valuable product.

[0148] In the optional step (iv), the water content of the organic phase can be reduced.

[0149] This is particularly advantageous if the product is later to be used for distributing water in fuels, see below.

[0150] For example, the product can be treated with water-binding compounds, such as zeolites or molecular sieves, to remove water, or it can be subjected to a membrane filtration process, in particular ultrafiltration, nanofiltration, and reverse osmosis. The membranes used have the property of retaining certain substances (such as organic compounds) and allowing others (such as inorganic salts or water) to pass through.

[0151] Preferably in step (iv) the water content of the organic phase is reduced by distillation, which can optionally be supported by passing a stripping gas, preferably the oxygen-poor gas, preferably lean air, nitrogen or argon, particularly preferably nitrogen.

[0152] Preferably, step (iv) is also carried out in the presence of a gas atmosphere in which the proportion of oxygen is not more than 10 vol%, preferably not more than 8, particularly preferably not more than 6, most particularly preferably not more than 5, in particular not more than 2 and especially not more than 1 vol%.

[0153] It is preferred to keep the thermal stress on the product during the distillation of water as low as possible by carrying out the distillation for no more than 4 hours at a temperature of no more than 100 °C and at reduced pressure.

[0154] Preferably, the distillation is carried out in less than 4 hours, particularly preferably in no more than 3h45min, most particularly preferably in no more than 3h30min.

[0155] The temperature during distillation should not exceed 100 °C, preferably not more than 98 °C and particularly preferably not more than 95 °C.

[0156] The distillation is carried out at reduced pressure, i.e., at ambient pressure, preferably at no more than 750 mbar, particularly preferably at no more than 500 mbar, most preferably at no more than 250 mbar, in particular at no more than 200 mbar and especially at no more than 150 mbar.

[0157] The combination of duration, temperature, and pressure is selected such that the water content in the organic phase is reduced to no more than 5 wt%, preferably no more than 4 wt%, particularly preferably no more than 3 wt%, most preferably no more than 2 wt%, and particularly no more than 1 wt%. Specifically, levels of no more than 0.75 wt%, and even no more than 0.5, 0.25, or 0.1 wt%, can be targeted.

[0158] Distillation can be carried out continuously or discontinuously in any manner. Preferably, the distillative separation of water takes place in a stirred tank with double-wall heating and / or internal heating coils under reduced pressure.

[0159] Of course, distillation can also be carried out by passing the mixture through a falling-film, thin-film, or wiper-blade evaporator one or more times. For this, the aqueous mixture is passed through the apparatus continuously or discontinuously under reduced pressure. To minimize the thermal stress on the distillation residue, the effluent is preferably cooled after passing through the evaporator.

[0160] Advantageously, an inert gas, preferably argon or a nitrogen-containing gas, particularly preferably argon, nitrogen or a mixture of air and nitrogen (lean air), most preferably nitrogen, can be introduced or passed through the distillation apparatus, for example 0.1 - 1, preferably 0.2 - 0.8 and particularly preferably 0.3 - 0.7 m 3 / m 3 h, relative to the volume of the liquid mixture.

[0161] Optionally, a rectification column with up to 10 theoretical trays can be added to the distillation apparatus; however, this is usually not necessary for the simple separation of water and is therefore less preferred.

[0162] By carrying out the process according to the invention, it is possible to reduce the initial content of oligo- and polyethylene glycols in the ethoxylated alkanols generally by at least 10%, preferably by at least 15%, particularly preferably by at least 20%, and most preferably by at least 25%. The process according to the invention makes it possible to remove the oligo- and polyethylene glycols almost completely and to reduce their formation during the process.

[0163] The initial content of (Earth)Al potassium imetal hones in the ethoxylated alkanols can generally be reduced by at least 20%, preferably by at least 30%, particularly preferably by at least 40% and most preferably by at least 50% and up to 95% or more.

[0164] The ethoxylated alkanols obtained, preferably obtained, according to the inventive process, which are depleted of oligo- and polyethylene glycols and / or (earth)alkali metal ions, can generally be used in all applications that are typically known for such ethoxylated alkanols that are not depleted.

[0165] These could include, for example, use as

[0166] - wetting agent

[0167] - Detergent

[0168] - Dispersing agent

[0169] - Solution mediator

[0170] - for textile cleaning and textile dyeing

[0171] - Intermediate for the synthesis of anionic phosphates, sulfates or ethercarboxylates

[0172] - as an adjuvant in agrochemical formulations: aids for improving the

[0173] - - Liability

[0174] - - Retention (spray retention aid)

[0175] - - Distribution - - Penetration

[0176] - - Wetting aid (spreading aid) for spray solutions.

[0177] However, ethoxylated alkanols are preferably used in applications where a reduced content of oligo- and polyethylene glycols and / or (earth) alkali metal ions is required.

[0178] These can be, for example, emulsifiers in w / o emulsions.

[0179] These ethoxylated alkanols with a reduced content of oligo- and polyethylene glycols and / or (earth)alkali metal ions are particularly advantageously used as a surfactant for the distribution, especially dispersion, of water in fuels selected from the group consisting of gasoline, diesel, marine fuels and aviation fuels, preferably diesel or aviation fuels, especially preferably aviation fuels, especially turbine fuels.

[0180] These ethoxylated alkanols make it possible to distribute a water content of at least 50 ppm in liquid hydrocarbon fuels in stable microemulsions with a droplet size of no more than 0.25 pim. This is particularly useful for reducing or suppressing the formation of ice particles in the fuel when cooled to minus 50°C. Furthermore, it prevents the formation of a separated water phase at the bottom of aircraft fuel tanks, which can lead to undesirable corrosion due to biofilm formation.

[0181] The ethoxylated alkanols can be used alone or preferably in combination with a (C8-C24)alkylamido (Ci-Cejalkyl betaine).

[0182] Such an application and corresponding mixtures are described in WO 2011 / 045334 A1 .

[0183] To reduce ice crystal formation, the following quantities are preferably added to the fuel:

[0184] - from 45 to 4575 ppm, preferably 45 to 500 ppm of at least one ethoxylated alkanol and / or

[0185] - from 0 to 425 ppm, e.g. 1 to 425 ppm, preferably 1 to 5 ppm of at least one (C8-C24)alkylamido (Ci-C6)alkyl betaine.

[0186] The at least one (C8-C24)alkyl amido (Ci-C6)alkyl betaine may preferably be Cocoamidopropyl betaine.

[0187] In addition to this surface-active agent or emulsifier, the fuel may contain one or more of the following additional components: static dissipators, antioxidants, metal deactivators, leak detection additives, corrosion inhibitors, lubricants, alcohols, glycols, and other standard products known to those skilled in the art, as well as impurities such as fatty acid methyl esters. The ethoxylated alkanols are mostly used in the form of liquid concentrates, essentially containing

[0188] 0.1 to 10 wt% of at least one (C8-C24)alkylamido (Ci-Cejalkyl betaine, preferably Cocoamidopropyl betaine) 30 to 95 wt% of at least one ethoxylated alkanol, with a reduced content of oligo- and polyethylene glycols and / or (earth)alkali metal ions

[0189] 0 to 20 wt% of at least one glycol-based solubility enhancer, preferably ethylene glycol, and 0 to 65 wt% of at least one organic solvent, preferably ethanol.

[0190] Analogous to WO 2011 / 045334 A1 is a preferred composition of the liquid concentrate

[0191] 2 parts cocoamidopropyl betaine

[0192] 60 parts of at least one ethoxylated alkanol, with a reduced content of oligo- and polyethylene glycols and / or (earth)alkali metal ions

[0193] 4 parts ethylene glycol, and 34 parts ethanol.

[0194] Turbine fuels contain a major proportion of liquid turbine fuel, such as a turbine fuel commonly used in civil or military aviation. Examples include fuels designated Jet Fuel A, Jet Fuel A-1, Jet Fuel B, Jet Fuel JP-4, JP-5, JP-7, JP-8, and JP-8+100. Jet A and Jet A-1 are commercially available kerosene-based turbine fuel specifications. The relevant standards are ASTM D 1655 and DEF STAN 91-91. Jet B is a more highly refined fuel based on naphtha and kerosene fractions. JP-4 is equivalent to Jet B. JP-5, JP-7, JP-8, and JP-8+100 are military turbine fuels, such as those used by the Navy and Air Force. In some cases, these standards specify formulations that already contain further additives, such as corrosion inhibitors, icing inhibitors, static dissipators, etc.

[0195] Furthermore, turbine fuels made from renewable biomass are conceivable; these are referred to as Sustainable Aviation Fuel (SAF). The requirements for these SAFs are specified in ASTM D7566, currently in revision 24d. Preferred SAFs are FT-SPK (Fischer-Tropsch Synthetic Paraffinic Kerosene, Annex 1 of ASTM D7566), HEFA-SPK (Hydroprocessed Esters and Fatty Acids, Annex 2 of ASTM D7566), HFS-SIP (Synthesized Iso-paraffin from Hydro-processed Fermented Sugar, Annex 3 of ASTM D7566), FT-SKA (Fischer Tropsch Synthetic Kerosene with Aromatics, Annex 4 of ASTM D7566), ATJ-SPK (Alcohol to Jet Synthetic Paraffinic Kerosene, from ethanol or iso-butanol, Annex 5 of ASTM D7566), CHJ (Catalytic Hydrothermolysis Synthesized Kerosene, Annex 6 of ASTM D7566) and HC-HEFA-SPK (Hydroprocessed Hydrocarbons, Annex 7 of ASTM D7566).Potential biomass feedstocks for SAFs include forestry waste, solid household waste, industrial exhaust gases, agricultural waste, used cooking oils (cooking oil, animal fat, tall oil), sugar, and algae. The resulting SAFs can currently be blended with conventional fossil turbine fuels at levels of up to 50%, or up to 10% in the case of HFS-SIP and HC-HEFA-SPK. SAFs can be produced, for example, using power-to-liquid (PtL) technology: Electricity is generated from renewable sources such as wind or solar power and used to split water into hydrogen and oxygen via electrolysis. The hydrogen obtained in this way is then combined with CO2, captured from the air or industrial processes, in several steps to produce an SAF, for example, through processes such as Fischer-Tropsch synthesis.

[0196] In the related Solar to Liquid (StL) process, energy is provided directly via solar thermal energy. Electrolysis is eliminated; water and CO2 are directly converted into a synthesis gas using solar energy. The subsequent steps correspond to Power to Liquid technology.

[0197] Further additives, known per se, may be added to the turbine fuel. Suitable additives that may be included in the turbine fuel composition typically include detergents, corrosion inhibitors, sulfur-free antioxidants such as sterically hindered tert-butylphenols, N-butylphenylenediamines or N,N'-diphenylamine and derivatives thereof, metal deactivators such as N,N'-disalicylidene-1,2-diaminopropane, solubilizers, antistatic agents such as Stadls 450, biocides, anti-icing agents such as diethylene glycol methyl ether or triethylene glycol methyl ether, and mixtures of the aforementioned additives.

[0198] Specifications for turbine fuel and approved additives with their respective dosages are listed in ASTM D 1655-24.

[0199] The microemulsions can be produced by mixing

[0200] - 99,995 to 99,999 parts, e.g. 99,998 parts, of a fuel, e.g. a turbine fuel and

[0201] - approximately 0.0001 to approximately 0.01 parts, e.g. 0.025 parts, emulsifier composition, wherein the emulsifier composition comprises

[0202] - - at least one (C8-C24)alkylamido (Ci-Cejalkyl betaine, preferably Cocoamidopropyl betaine and

[0203] - - at least one ethoxylated alkanol, with a reduced content of oligo- and polyethylene glycols and / or (earth) alkali metal ions, wherein the proportions always refer to volume.

[0204] Accordingly, a further object of the present invention is a method for distributing water in fuels using ethoxylated alkanols of the formula

[0205] R 1 -O-[-CH2-CH2-O-] m -H wherein

[0206] R 1 straight-chain or branched Cs-Cu alkyl, preferably Cs-C alkyl, particularly preferably Cg-C alkyl, and most preferably Cg-Cn alkyl and m a rational number of 1 to 3 with a reduced content of oligo- and polyethylene glycols of the formula

[0207] HO-[-CH2-CH2-O]nH wherein n is a rational number of at least 2, preferably from 2 to 30 and particularly preferably from 2 to 20, and a simultaneously reduced content of (earth)alkali metal ions, wherein one

[0208] (I) an alkanol R 1-OH reacts with at least m equivalents of ethylene oxide in the presence of at least one basic salt of at least one (earth)alkali metal and in the presence of water at a temperature of 20 to 200 °C to obtain a mixture of oligo- and polyethylene glycols and ethoxylated alkanols and

[0209] (II) subjects the mixture thus obtained to a purification process in which

[0210] (I) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase,

[0211] (II) allows the phases to separate at a temperature of 30 to 90 °C,

[0212] (ill) separates the organic from the aqueous phase and

[0213] (iv) optionally reduces the water content of the organic phase,

[0214] (III) mixes the oligo- and polyethylene glycol-depleted, ethoxylated alkanol thus obtained into a fuel selected from the group consisting of gasoline, diesel, marine fuels and aviation fuels.

[0215] Examples

[0216] Materials and methods

[0217] On average, a 2.5-fold ethoxylated mixture of Cg-Cn alkanols, for example Synperonic™ 91 / 2.5 from Croda, GAS 68439-46-3.

[0218] Potassium levels were measured using ICP-OES

[0219] PEG content was measured against a PEG standard using HPLC-MS. PEG standards of the respective molar mass range, determined in the sample by MS, were used. Water content was measured by volumetric Karl Fischer titration.

[0220] Determination of the dissolved oxygen content in liquids

[0221] In a glass vessel with a septum and an inlet tube for the stripping gas ending in a glass frit, demineralized water is placed in a quantity sufficient to cover the frit and the syringe tip. This is then connected to the measuring cell (electrochemical oxygen measuring cell ("heart cell" from Pro-Chem Analytik GmbH & Co. KG, Kamp-Lintfort, Germany (O2-Sensor 16T304), Range 2). Nitrogen is then passed through the measuring cell and the water at ambient temperature as the stripping gas at a pressure of 150 kPa until the measuring device is oxygen-free, as indicated by the oxygen cell's signal. Optimal mixing of the two liquids is ensured by the bubbling stripping gas. 100 to 200 pl of the sample are then dosed into the water through the septum using a syringe, and the measurement process is initiated.The measurement process ends when the signal from the oxygen sensor returns to the same level as before the sample was added. The oxygen sensor signal is recorded and analyzed using a laboratory data system. The O2 content is calculated via a calibration measurement, taking into account the current air pressure and ambient temperature.

[0222] Calibration:

[0223] To calibrate the measuring arrangement, a defined quantity of a calibration gas with a known oxygen content is dosed into the measuring cell with liquid reservoir using a gas-tight syringe, and the resulting measurement signal is evaluated using the laboratory data system.

[0224] The experiments were conducted in double-jacketed reactors with a multi-stage inclined-blade stirrer, thermostat, and bottom drain. Phase separations were achieved by draining the aqueous phase through the bottom drain valve.

[0225] Example 1

[0226] According to ASTM D 1094 - 07, 80 ml of an aviation fuel of specification Jet A-1 were shaken at ambient temperature with 20 ml of pH 7 buffer solution and the amount of additive and polyethylene glycol of mean molar weight 400 g / mol (PEG400) specified in the table, based on the fuel, and the phases and their separation were evaluated in a 100 ml graduated cylinder after periods of 5, 30 and 60 minutes.

[0227] The additive has the composition according to Example 4 of WO 2011 / 045334 A1, wherein the ethoxylated alkanol is an on average 2.5-fold ethoxylated mixture of Cg-Cn alkanols. Table 1

[0228] [1] individual stable water droplets in organic phase

[0229] The mixed phase is a cloudy phase between the aqueous and organic phases.

[0230] It can be seen that the additive, without the presence of polyethylene glycol (entries 2 and 4), results in good phase separation with little or no mixed phase.

[0231] The presence of polyethylene glycol causes an increase in the mixed phase (entries 1 and 3 compared to 2 and entry 5 compared to 4).

[0232] The presence of polyethylene glycol therefore results in a deterioration of the phase separation between water and aviation fuel.

[0233] Example 2

[0234] 500 g of ethoxylated alkanol (PEG content: 0.92 wt%, potassium content: 0.1 wt%, water content: 0.3 wt%) and 250 ml of desalinated water were heated to 80°C under a nitrogen atmosphere and stirred at this temperature for 30 min.

[0235] The aqueous phase was separated at 80°C. 250 ml of water were added and the mixture was stirred for 30 minutes at 80°C. The aqueous phase was then separated. The ethoxylate was extracted three more times in this manner, each time with 250 ml of desalinated water (a total of five extractions were performed, each with 250 ml of desalinated water).

[0236] After the final phase separation, the organic phase (549 g) contained 11.8% water. The water was removed using a rotary evaporator at 100°C under vacuum. The final product showed a water content of 0.2%, a potassium content of 4 ppm, and a PEG content of <50 ppm. Example 3

[0237] This experiment was conducted in an atmospheric environment and the ethoxylated alkanol was not degassed:

[0238] 1000 g of a 2.5-fold ethoxylated mixture of Cg-Cn alkanols (PEG content 109 ppm) was heated to 80°C, mixed with 500 g of demineralized water, and the mixture was then stirred for 1 h at 80°C. The phases were allowed to separate for 17 h, and the aqueous phase (332.5 g, aqueous phase 1) was collected. Another 500 g of demineralized water was added, the mixture was stirred for 1 h at 80°C, the phases were allowed to separate for 1.5 h, and the aqueous phase (490.8 g, aqueous phase 2) was collected. The water was distilled off the organic phase under vacuum (80°C / 100 mbar).

[0239] 980 g of ethoxylated alkanol with a water content of 0.01% was obtained.

[0240] The following PEG levels were determined:

[0241] The mass balance shows that the ethoxylated alkanol contained 109 mg of PEG at the beginning of the experiment, and the three phases together contained 302 mg of PEG at the end of the experiment. During the experiment, 193 mg of PEG were newly formed (177% of the original amount). The experiment further demonstrates that the PEG content cannot be reduced by extraction in the presence of oxygen.

[0242] Example 4:

[0243] This experiment was carried out under a nitrogen atmosphere and the ethoxylated alkanol (400 g) was degassed by passing a nitrogen stream (10 L / h) through it for 30 min:

[0244] 400 g of a 2.5-fold ethoxylated mixture of Cg-Cn alkanols (PEG content 109 ppm) were heated to 80°C, mixed with 200 g of demineralized water, and the mixture was then stirred for 30 min at 80°C. The phases were allowed to separate for 1.5 h.

[0245] A sample from the organic phase showed a water content of 18.2% and a PEG content of 50 ppm. Calculated based on the anhydrous ethoxylated alkanol, the PEG content was accordingly reduced to 61 ppm.

[0246] This experiment, compared to Example 3, shows that excluding oxygen during extraction can lead to a reduction in the PEG content of the ethoxylated alkanol. Example 5:

[0247] This experiment was carried out under a nitrogen atmosphere and the ethoxylated alkanol (600 g) and the desalinated water were degassed by passing a nitrogen stream (10 L / h) through them for 15 h:

[0248] 600 g of a 2.5-fold ethoxylated mixture of Cg-Cn alkanols (PEG content 109 ppm) were heated to 80°C, mixed with 300 g of demineralized water, and the mixture was then stirred for 30 min at 80°C. The phases were allowed to separate for 2 h, and the aqueous phase (186 g), containing 249 ppm PEG, was separated. The organic phase (714 g, 15.7% water) contained 34 ppm PEG.

[0249] The mass balance shows that the two phases contained a total of 71 mg of PEG at the end of the experiment, while the ethoxylated alkanol contained 65 ppm PEG at the beginning of the experiment. During the course of the experiment, 6 mg of PEG were newly formed (9% of the original amount).

[0250] Example 6:

[0251] This experiment was carried out under a nitrogen atmosphere and the ethoxylated alkanol (1000 kg) was previously degassed by passing a nitrogen stream (1500 L / h) through it for 6 h at ambient temperature.

[0252] 1000 kg of a 2.5-fold ethoxylated mixture of Cg-Cn alkanols (PEG content 98 ppm) was heated to 80°C, mixed with 500 kg of demineralized water (90°C), and the mixture was then stirred for 1 h at 80°C. The phases were allowed to separate for 6 h, and the aqueous phase (320 kg, 188 ppm PEG) was separated. The water from the organic phase was distilled off under vacuum (80°C, 100 mbar) to a water content of 0.4%.

[0253] The ethoxylated alkanol (995 kg) was obtained with a PEG content of 41 ppm.

[0254] The mass balance shows that 3% of the originally present amount of PEG was newly formed during the course of the experiment (98 g PEG at the beginning, 101 g PEG at the end of the experiment). Example 7:

[0255] The dissolved oxygen content in the mixture of Cg-Cn alkanols, which had been ethoxylated on average 2.5-fold, was determined as described above. The samples were pretreated as follows:

[0256] Sample A: no treatment

[0257] Sample B: Air (10 L / h) was passed through the sample (100 g) at room temperature for 3 hours.

[0258] Sample C: Passing 10 l / h of nitrogen through the sample (600 g) at room temperature overnight for 15 h, analogous to Example 5

[0259] Results

[0260] It can be seen that the dissolved oxygen content in the ethoxylated alkanol can be reduced by passing an inert gas through it. The saturation limit for oxygen in the ethoxylated alkanol used is approximately 23 mg of oxygen per kg of ethoxylated alkanol at room temperature.

Claims

Patent claims 1. Method for separating oligo- and polyethylene glycols of the formula HO-[-CH2-CH2-O]nH wherein n is a rational number of at least 2, preferably of 2 to 30 and particularly preferably of 2 to 20 from ethoxylated alkanols of the formula R 1 -O-[-CH2-CH2-O-] m -H wherein R 1 straight-chain or branched, preferably straight-chain Cs-Cu alkyl, preferably Cs-C alkyl, particularly preferably Cg-C alkyl, and most preferably C9-C1 i-alkyl, and m is a rational number from 1 to 3, wherein one (I) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase, (II) allows the phases to separate at a temperature of 30 to 90 °C, (ill) separates the organic from the aqueous phase, (iv) optionally reducing the water content of the organic phase, characterized in that the extraction is carried out in the presence of a gas atmosphere in which the proportion of oxygen is not more than 10 vol%, preferably not more than 8, particularly preferably not more than 6, most particularly preferably not more than 5, in particular not more than 2 and especially not more than 1 vol%.

2. Method for separating oligo- and polyethylene glycols of the formula HO-[-CH2-CH2-O] n -H where n is a rational number of at least 2, preferably from 2 to 30 and particularly preferably from 2 to 20 from ethoxylated alkanols of the formula R 1 -O-[-CH2-CH2-O-] m -H wherein R 1straight-chain or branched, preferably straight-chain Cs-Cu alkyl, preferably Cs-C alkyl, particularly preferably Cg-C alkyl, and most preferably Cg-Cn alkyl, and m is a rational number from 1 to 3, wherein one (i) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase, (ii) allows the phases to separate at a temperature of 30 to 90 °C, (iii) separates the organic phase from the aqueous phase, (iv) optionally reduces the water content of the organic phase, characterized in that, prior to extraction, the dissolved oxygen content in the ethoxylated alkanol is reduced to no more than 25% of the saturation at storage temperature, preferably to the saturation at 20 °C, preferably to no more than 20%, particularly preferably to no more than 15% and most particularly preferably to no more than 10%.

3. Method according to claim 1 or 2 for the simultaneous separation of oligo- and polyethylene glycols and (Earth)al potassium imetallic ions from ethoxylated alkanols, which are formed by the reaction of an alkanol R 1 -OH with at least m equivalents of ethylene oxide in the presence of at least one basic salt of at least one (earth)alkali metal.

4. Method for the preparation of ethoxylated alkanols of the formula R 1 -O-[-CH2-CH2-O-] m -H wherein R 1straight-chain or branched Cs-Cu alkyl, preferably Cs-C alkyl, particularly preferably Cg-C alkyl, and most preferably Cg-Cn alkyl, and m a rational number of 1 to 3 with a reduced content of oligo- and polyethylene glycols of the formula HO-[-CH2-CH2-O]nH wherein n is a rational number of at least 2, preferably from 2 to 30 and particularly preferably from 2 to 20, and a simultaneously reduced content of (earth)alkali metal ions, wherein one (I) an alkanol R 1 -OH reacts with at least m equivalents of ethylene oxide in the presence of at least one basic salt of at least one (earth)alkali metal and in the presence of water at a temperature of 20 to 200 °C to obtain a mixture of oligo- and polyethylene glycols and ethoxylated alkanols and (II) subjects the mixture thus obtained to a purification process in which (I) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase, (II) allows the phases to separate at a temperature of 30 to 90 °C, (ill) separates the organic from the aqueous phase, (iv) optionally reducing the water content of the organic phase, characterized in that the extraction is carried out in the presence of a gas atmosphere in which the proportion of oxygen is not more than 10 vol%, preferably not more than 8, particularly preferably not more than 6, most particularly preferably not more than 5, in particular not more than 2 and especially not more than 1 vol%.

5. Method according to claim 1, 2 or 4, characterized in that at least one of the steps (I), (II) or (ill) in the presence of an oxygen-deficient gas atmosphere, preferably at least one of the steps (ii) or (ill), particularly preferably at least the step (ii), most particularly preferably at least the steps (ii) and (ill) and in particular all three steps (i), (ii) and (ill).

6. A method according to one of the preceding claims, characterized in that such reaction steps are carried out in the presence of an oxygen-deficient gas atmosphere in which the temperature of the ethoxylated alkanol reaches or exceeds at least 50 °C.

7. Method according to one of the preceding claims, characterized in that steps (i) to (iii) passes through one to ten times, preferably one to eight times, most preferably one to six times.

8. Method according to one of the preceding claims, characterized in that the content of dissolved oxygen in the ethoxylated alkanol and / or in the water is reduced before use in the extraction, preferably at least in the ethoxylated alkanol, particularly preferably in both the ethoxylated alkanol and in the water.

9. Method according to claim 8, characterized in that the content of dissolved oxygen in the ethoxylated alkanol is reduced during extraction by applying a vacuum and / or passing a stripping gas, preferably an oxygen-depleted gas or water vapor.

10. Method according to claim 8, characterized in that the dissolved oxygen content in the mixture of ethoxylated alkanol and oligo- and polyethylene glycols is reduced by at least 20% compared to the saturation oxygen content of the mixture at 20 °C and normal pressure before use in the extraction.

11. Method according to claim 8, characterized in that the dissolved oxygen content in the Water reduced by heating to a temperature of at least 50°C.

12. Method according to one of the preceding claims, characterized in that an additional step is performed. (iv) is carried out in the presence of a gas atmosphere in which the proportion of oxygen is not more than 10 vol%, preferably not more than 8, particularly preferably not more than 6, most particularly preferably not more than 5, in particular not more than 2 and especially not more than 1 vol%.

13. Method according to one of the preceding claims, characterized in that the alkanol R 1 -OH R 1= C9-C1 i-alkyl and m = 2.5 and the content of dissolved oxygen in the ethoxylated alkanol is not more than 6 ppm, preferably not more than 5, particularly preferably not more than 4, very particularly preferably not more than 3 and particularly preferably not more than 2 ppm.

14. Method according to any one of claims 1 to 12, characterized in that the alkanol is R 1 -OH is a mixture of alcohols having about 13 carbon atoms, obtainable by hydroformylation from a Ci2 olefin mixture, and has a mean degree of branching, measured as ISO index, of 1.8 to 2.

7.

15. Method according to any one of claims 1 to 13, characterized in that the alkanol is R 1 -OH is a mixture of primary alcohols with the composition 15-20 wt% C9-, 40-45 wt% Gw and 35 to 40 wt% Cn alcohols, wherein the proportion of alcohols with 8 or fewer or with 12 or more carbon atoms is not more than 1 wt% in each case.

16. Use of oligo- and polyethylene glycol- and optionally (earth)alkali metal-depleted ethoxylated Alkanols are obtained by one of the above methods for distributing water in fuels, especially gasoline, diesel, marine fuels and aviation fuels.

17. Use of oligo- and polyethylene glycol- and optionally (earth)alkali metal-depleted ethoxylated Alkanols are obtained according to one of the methods according to one of claims 1 to 13 as - wetting agent - Detergent - Dispersing agent - Solution mediator - for textile cleaning and textile dyeing - Intermediate for the synthesis of anionic phosphates, sulfates or ethercarboxylates - as an adjuvant in agrochemical formulations: aids for improving the - - Liability - - Retention (spray retention aid) - - Distribution - - Penetration - - Wetting aid (spreading aid) for spray solutions.

18. Method for distributing water in fuels using ethoxylated alkanols of the formula R 1 -O-[-CH2-CH2-O-] m -H wherein R 1 straight-chain or branched Cs-Cu alkyl, preferably Cs-Cia alkyl, particularly preferably Cg-C alkyl, and most preferably Cg-Cn alkyl and m a rational number of 1 to 3 with a reduced content of oligo- and polyethylene glycols of the formula HO-[-CH2-CH2-O] n -H where n is a rational number of at least 2, preferably from 2 to 30 and particularly preferably from 2 to 20, and a simultaneously reduced content of (earth) alkali metal ions, in which one (I) an alkanol R 1 -OH reacts with at least m equivalents of ethylene oxide in the presence of at least one basic salt of at least one (earth)alkali metal and in the presence of water at a temperature of 20 to 200 °C to obtain a mixture of oligo- and polyethylene glycols and ethoxylated alkanols and (II) subjects the mixture thus obtained to a purification process in which (i) the mixture of oligo- and polyethylene glycols and ethoxylated alkanols mixed at a temperature of ambient temperature up to 90 °C with 0.05 to 10 times, for example 0.05 to 2.0 times, preferably 0.1 to 1.5 times, particularly preferably 0.15 to 1.0 times, most preferably 0.25 to 0.75 times the volume (v / v) of water per 1 volume of organic phase, (II) allows the phases to separate at a temperature of 30 to 90 °C, (ill) separates the organic from the aqueous phase and (iv) optionally reducing the water content of the organic phase, the extraction being carried out in the presence of a gas atmosphere in which the oxygen content is not more than 10 vol%, preferably not more than 8, particularly preferably not more than 6, most particularly preferably not more than 5, in particular not more than 2 and especially not more than 1 vol%, (III) mixes the oligo- and polyethylene glycol-depleted, ethoxylated alkanol thus obtained into a fuel selected from the group consisting of gasoline, diesel, marine fuels and aviation fuels.

19. Fuel comprising an oligo- and polyethylene glycol-depleted, ethoxylated alkanol obtained according to a process according to any one of claims 1 to 13.

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