EP2235144B1 - Production of additive mixtures - Google Patents

Description

The present invention relates to a process for the preparation of additive mixtures for fuel oils by mixing at least two additive components in a mixing pump.

Paraffinic waxes containing mineral oils and crude oils show a significant deterioration in the flow properties when the temperature is lowered. The reason for this lies in the crystallization of longer-chain paraffins occurring from the cloud point temperature (cloud point), which form large platelet-shaped wax crystals. These wax crystals have a sponge-like structure and lead to the inclusion of other fuel constituents in the crystal composite.

The appearance of these crystals leads to a deterioration in the flow properties of the mineral oils and crude oils, which may interfere with the recovery, transportation, storage and / or use of the oils. So it can come during the transport of oils through pipes, especially in winter to deposits on the pipe walls and even to complete blockage. The mineral oils can lead to the blockage and sticking of fuel filters in motor vehicle engines (fuel filters) and firing systems, whereby a safe metering of the fuels is prevented and possibly a complete interruption of the fuel supply occurs. At temperatures below the pour point (Pour Point, PP), finally, no fuel flow takes place.

To remedy these problems, it has long been possible to add additives in small concentrations to mineral oils and crude oils, which often consist of a combination of nucleators with the actual cold flow improvers (CFI). Nucleators are substances that generate crystal nuclei that promote the formation of micro-crystals. Cold flow improvers have similar crystallization properties as the paraffins contained in mineral oil or crude oil, but prevent their growth. Furthermore, Wax Anti-Settling Additives (WASA) are added to the crude oils and mineral oils to prevent the micro-crystals from sinking into the oils. Frequently mixtures of CFI and WASA are used, which are also referred to as WAFI (wax anti-settling flow improvers).

These cold flow improvers are usually added to the mineral oils and crude oils as additive packages. Aside from the cold flow improvers, these additive packages generally contain at least one solvent and frequently also further additives, for example detergent additives, dispersants, defoamers and others.

Since the composition of crude oils and mineral oils varies due to the different origins of the crude oils and the different processing conditions in the refineries, more or less tailor-made additive packages have to be provided for the individual oils. It is therefore of great economic importance to be able to provide the additive packages in a fast, flexible process with reliably reproducible results. At the same time the additive packages should not only have good functional properties, such as good cold flow improving properties, but also have good handling properties, for example, be easily incorporated into the oil.

In general, additive mixtures are prepared in batches, d. H. one or more active substance components and a solvent are metered successively into a container and then mixed by stirring or pumping over. The disadvantage here is the long time that is needed for charging, heating and mixing. Achieving sufficient homogeneity requires, especially when mixing active ingredients and solvents of different viscosity, a longer stirring or circulation over several hours to days. The desired or required mixing temperature sets itself in accordance with the amounts of the components to be mixed and their temperatures and the set heating power generally only slowly. Often, for example, it deviates significantly from the mean value at the metering point of the components as well as at the heating elements, so that the temperature profile during the mixing process is difficult to reproduce. Especially with rapid heating on the heating elements, e.g. the vessel shell, significant overheating may occur, which can lead to sedimentation of the suspended active ingredients or their thermal decomposition in the subsequent storage of the additive packages.

Furthermore, the flowability or pumpability of dispersions of these semicrystalline polymers is often dependent on the mixing conditions. Thus, partially or incompletely melted formulations of semicrystalline polymers with solvents and optionally other active ingredients lead to dispersions with a high intrinsic pour point (PP), whereas completely molten polymers give dispersions with a significantly lower pour point. The targeted adjustment of an important for product handling constant pour point of the formulation produced is thus possible in batch mixing only with great technical and / or time additional effort, for example by heating or cooling the finished mixture.

The EP-A-1405896 describes a continuous process for the preparation of additive mixtures for mineral oils and mineral oil distillates, in which a cold flow improver is mixed with another cold flow improver or a solvent in a static mixer at a defined temperature. Static mixers are Mixing systems in which the energy required for the mixing process is entered by the mixing components. They often contain fixed installations and cause a mixing of the components by exploiting their flow energy.

While the additive blends obtained with this blending process no longer have many of the disadvantages of the additive blends obtained with the older batch blending processes; Also, the mixing process is much faster. However, some handling characteristics are with the procedure of EP-A-1405896 obtained additive mixtures, such as the lower mixing temperature and the filterability, still not satisfactory. In addition, it is almost impossible with static mixers, completely and homogeneously to mix components with very different viscosities or even components that are present in very different proportions in the mixture.

The object of the present invention was therefore to provide additive mixtures for fuel oils which, in addition to good functional properties (ie properties for which these additives are added to the fuel oils at all, eg cold flow-improving properties) have improved handling properties in comparison with additive mixtures of the prior art, for example, a lower Mindestemmischtemperatur (UET) and / or better filterability of the additive fuel oil. In addition, they should also have improved storage stability. Furthermore, the additive mixtures should also be able to be homogeneously composed of components which have a strongly differing viscosity and / or should be present in greatly varying proportions in the mixture.

The minimum blending temperature is an important economic factor for blending the fuel oils with the additives, because the lower the minimum blending temperature of an additive, the less fuel oil must be heated to mix the additive homogeneously. The Mindestemmischtemperatur is thus particularly relevant for such refineries, mix the additives unheated in fuel oils or mix additives in unheated fuel oils. If the minimum mixing temperature of the additive is high, filter problems may occur after unheated mixing.

The filterability of additized fuel oils is a measure of the solubility and miscibility of the additive used in the fuel oil. In the context of the present invention, the filterability is determined by means of the SEDAB method described below. Good filterability is obtained if the added additive is readily mixable or soluble in the fuel oil.

A longer storage stability is also a significant economic factor, as it allows the production of the products in stock, so that, for example, demand peaks can be met more easily or run production rounds (for individual additive compositions) longer and thus more economical, without prolonged storage, the product quality unacceptable sinks.

The object has been achieved by a process for the preparation of additive mixtures for fuel oils, in which at least two components of the additive mixture are mixed in a mixer selected from mixed pumps, the at least two components of the additive mixture (i) comprising at least one cold flow improver and (ii ) comprise at least one solvent; wherein the cold flow improver is selected from copolymers of ethylene with at least one other ethylenically unsaturated monomer selected from alkenylcarboxylic acid esters, (meth) acrylic acid esters, styrene, styrene derivatives and olefins other than ethylene, and the solvent is selected from aliphatic and aromatic hydrocarbons and mixtures thereof ,

The statements made below on suitable and preferred embodiments of the method according to the invention, in particular of the components to be mixed and the mixing conditions, apply both taken alone and in any conceivable combination with one another.

In dynamic mixers, the energy input required for the mixing process takes place through the mixer itself. These contain moving mixing elements or a moving container. Most common are so-called rotor-stator systems with a fixed housing (stator) and a rotating machine part (rotor). In the spaces between the rotor and the stator, a shear flow is formed by the rotating movement of the rotor, which is often, but not necessarily, turbulent. In this shear flow, the mixing of the components takes place by constantly creating new phase interfaces between them.

Examples of dynamic mixers are rotor mills, sprocket dispersing machines, in-line dispersing machines, colloid mills, corundum disk mills, scraped surface heat exchangers, mixing pumps and ultrasonic homogenizers. According to the invention, the dynamic mixers are selected among mixing pumps.

In the process according to the invention, the mixing of the components can also take place in a plurality of mixers arranged in any order, arrangement or combination, at least one of the mixers being a mixing pump. The remaining mixers may be any desired mixer shapes, for example one or more further dynamic mixers and / or lamination mixers and / or static mixers. The mixers may be arranged in series or in a combined series and parallel arrangement.

Lamination mixers are a special form of non-dynamic mixers in which the fluid streams to be mixed are fanned into a multiplicity of thin lamellae or films, and these lamellae are then alternately combed into each other, so that very rapid mixing occurs through diffusion and secondary flows. The fanning of the inflows of the pure mixture component can be done for example by means of flow dividers, which divide the inflows into lamellar layers or films of adjustable thickness. By means of a corresponding spatial arrangement, an alternating stratification of the lamellar pure substance flows is brought about at the outlet from the flow divider, which, depending on the design, can be constructed two-dimensionally in adjacent planes or as concentric annular flows. By diffusion then takes place a material concentration balance between the layers and thus a mixing of the components instead.

However, in the method according to the invention, mixing of the components preferably takes place in a single mixer.

The mixing of the components is preferably carried out at elevated temperature, preferably at least 30 ° C, e.g. at 30 to 180 ° C or 30 to 150 ° C or 30 to 100 ° C, more preferably at least 50 ° C, e.g. at 50 to 180 ° C or at 50 to 150 ° C or at 50 to 100 ° C, and especially at least 70 ° C, e.g. at 70 to 180 ° C or at 70 to 150 ° C or at 70 to 100 ° C. The various components may have different input temperatures at the mixer.

The desired mixing temperature can be set both before and during the mixing process. The adjustment of the temperature before the mixing process is usually carried out by bringing the components to be mixed shortly before they are fed into the mixer to the desired temperature or kept in a storage container at the desired temperature. If, during the supply, the temperature can drop, the components are usefully brought first to a higher temperature, which drops during the feeding to the desired mixing temperature. The adjustment of the temperature during the mixing process is usually via heating elements, which are installed on or in the mixer, for example via a double jacket or a tube bundle. Preferably, the mixing temperature is adjusted before the mixing process by heating the components to be mixed to the desired or a slightly higher temperature.

The feeding of the components in the mixer can be carried out by conventional methods, for example by direct addition of all components in pure form or by adding suitable premixes. If premixes are used, then these are formed in a separate step or, as mentioned above, be prepared in a the actual (mixing pump) upstream mixer.

The setting of a homogeneous mixture with the desired product properties in the process according to the invention generally requires at most 200 seconds, preferably at most 120 seconds, more preferably at most 60 seconds and in particular at most 45 seconds, especially at most 30 seconds. These times are the average mixing time, i. the mean residence time of the components in the mixing zone.

The process of the invention can be configured as a batch, semibatch or continuous process. Preferably, however, it is a continuous process.

In the continuous process, the material throughput is preferably from 0.001 to 200 t / h, particularly preferably from 0.01 to 100 t / h and in particular from 1 to 100 t / h.

In the continuous process variant, a mixing pump is usually supplied with the components to be mixed via suitable supply lines, the supply of the components in the mixing pump, as already stated, either by direct addition of all components in pure form or by adding suitable premixes. The pure components are preferably brought before entry into the mixer by suitable measures to the desired mixing temperature or a temperature slightly above the desired mixing temperature. Since the mixing time / residence time is usually very short, it is usually not necessary in stationary continuous operation to heat the mixer. After mixing, the mixture is then discharged continuously from the mixer.

After the mixing process, it is favorable to cool the mixture formed before discharge from the mixing plant. Suitable are all conventional cooling devices, in particular those for indirect cooling, such as heat exchangers. This ensures that the mixture remains stable at ambient temperature.

1. (i) wenigstens einen Kaltfließverbesserer und
2. (ii) wenigstens ein Lösungsmittel.

In a preferred embodiment of the invention, the method according to the invention is used for the production of CFI additive packages. Accordingly, the at least two components of the additive mixture comprise

1. (i) at least one cold flow improver and
2. (ii) at least one solvent.

Component (i) and component (ii) are used in a weight ratio of preferably 1:99 to 99: 1, particularly preferably from 10:90 to 90:10 and in particular from 20:80 to 80:20.

The cold flow improvers used according to the invention are (a) copolymers of ethylene with at least one further ethylenically unsaturated monomer or mixtures thereof with (d) at least one polar nitrogen compound.

In the copolymers of ethylene with at least one other ethylenically unsaturated monomer (a), the monomer is selected from alkenylcarboxylic acid esters, (meth) acrylic acid esters, styrene, styrene derivatives and olefins.

Suitable olefins are, for example, those having 3 to 10 carbon atoms and having 1 to 3, preferably 1 or 2, in particular having one, carbon-carbon double bond. In the latter case, the carbon-carbon double bond can be arranged both terminally (α-olefin) and internally. However, preferred are α-olefins, more preferably α-olefins having 3 to 6 carbon atoms, such as propene, 1-butene, 1-pentene and 1-hexene.

Suitable styrene derivatives are C ₁ -C ₄ -alkyl-substituted styrenes, such as α-methylstyrene, 2-, 3- or 4-methylstyrene, 2-, 3- or 4-ethylstyrene, 2-, 3- or 4-propylstyrene, 4 Isopropylstyrene, 2-, 3- or 4-n-butylstyrene, 4-isobutylstyrene, 4-tert-butylstyrene, 2,4- or 2,6-dimethylstyrene and 2,4- or 2,6-diethylstyrene. Preference is given here to α-methylstyrene, 2-, 3- or 4-methylstyrene and 2,4- or 2,6-dimethylstyrene and in particular 2-, 3- or 4-methylstyrene and 2,4- or 2,6-dimethylstyrene.

Suitable (meth) acrylic esters are, for example, esters of (meth) acrylic acid with C ₁ -C ₂₀ -alkanols, in particular with methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol, pentanol, hexanol, Heptanol, octanol, 2-ethylhexanol, nonanol, decanol, 2-propylheptanol, undecanol, lauryl alcohol, tridecanol, myristyl alcohol, pentadecanol, palmityl alcohol, heptadecanol, stearyl alcohol, nonadecanol and eicosanol.

Suitable alkenylcarboxylic esters are, for example, the vinyl and propenyl esters of carboxylic acids having 2 to 20 carbon atoms, the hydrocarbon radical of which may be linear or branched. Preferred among these are the vinyl esters. Among the carboxylic acids with a branched hydrocarbon radical, preference is given to those whose branching is in the α-position to the carboxyl group, the α-carbon atom being particularly preferably tertiary, ie the carboxylic acid being a so-called neocarboxylic acid. Preferably, however, the hydrocarbon radical of the carboxylic acid is linear.

Examples of suitable alkenylcarboxylic esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl neopentanoate, vinyl hexanoate, vinyl neononanoate, vinyl neodecanoate and the corresponding propenyl esters, with vinyl esters being preferred. A particularly preferred alkenyl carboxylic acid ester is vinyl acetate.

Particularly preferably, the ethylenically unsaturated monomer is selected from alkenylcarboxylic esters. More preferably, the ethylenically unsaturated monomer comprises vinyl acetate.

Also suitable are copolymers which contain two or more mutually different alkenylcarboxylic acid esters in copolymerized form, these differing in the alkenyl function and / or in the carboxylic acid group. One of the alkenylcarboxylic esters is preferably vinyl acetate. Also suitable are copolymers which, in addition to the alkenylcarboxylic ester (s), contain at least one olefin and / or at least one (meth) acrylic ester and / or styrene and / or at least one styrene derivative in copolymerized form. Preferred among these are terpolymers, i. Copolymers which, in addition to an alkenylcarboxylic acid ester, which is preferably vinyl acetate, contain in copolymerized form an olefin or a (meth) acrylic acid ester or styrene or a styrene derivative. With regard to suitable and preferred olefins, alkenylcarboxylic acid esters, (meth) acrylic acid esters and styrene derivatives, reference is made to the above statements.

The at least one ethylenically unsaturated monomer is copolymerized in the copolymer in a total amount of preferably from 1 to 30 mol%, particularly preferably from 1 to 25 mol% and in particular from 5 to 20 mol%, based on the total copolymer.

The copolymer (a) preferably has a number average molecular weight M _n of 500 to 20,000, particularly preferably 750 to 15,000.

The polar nitrogen compounds (d), which are suitably oil-soluble, may be both ionic and nonionic and preferably have at least one, more preferably at least 2, substituents of the formula> NR ²² , wherein R ^{22 is} a C ₈ -C ₄₀ hydrocarbon radical , The nitrogen substituents may also be quaternized, that is in cationic form. An example of such nitrogen compounds are ammonium salts and / or amides or imides obtainable by reacting at least one amine substituted with at least one hydrocarbyl radical with a carboxylic acid having 1 to 4 carboxyl groups or with a suitable derivative thereof. The amines preferably contain at least one linear C ₈ -C ₄₀ -alkyl radical. Examples of suitable primary amines are octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tetradecylamine and the higher linear homologs. Suitable secondary amines are, for example, dioctadecylamine and methylbehenylamine. Also suitable are amine mixtures, in particular industrially available amine mixtures, such as fatty amines or hydrogenated tallamines, as used, for example, in US Pat Ullmann's Encyclopedia of Industrial Chemistry, 6th edition, 2000 electronic release, chapter "Amines, aliphatic Suitable acids for the reaction are, for example, cyclohexane-1,2-dicarboxylic acid, cyclohexene-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, naphthalenedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid and succinic acids substituted by long-chain hydrocarbon radicals.

Another example of polar nitrogen compounds are ring systems bearing at least two substituents of the formula -A-NR ²³ R ²⁴ wherein A is a linear or branched aliphatic hydrocarbon group optionally substituted by one or more groups selected from O, S , NR ³⁵ and CO, is interrupted, and R ²³ and R ^{24 are} a C ₉ -C ₄₀ -hydrocarbon radical, which is optionally interrupted by one or more groups selected from O, S, NR ³⁵ and CO, and / or substituted by one or more substituents selected from OH, SH and NR ³⁵ R ³⁶ , wherein R ^{35 is} C ₁ -C ₄₀ alkyl optionally substituted by one or more moieties selected from CO, NR ³⁵ , O and S, interrupted, and / or substituted by one or more radicals selected from NR ³⁷ R ³⁸ , OR ³⁷ , SR ³⁷ , COR ³⁷ , COOR ³⁷ , CONR ³⁷ R ³⁸ , aryl or heterocyclyl, wherein R ³⁷ and R ³⁸ each una depending on one another, are selected from H or C ₁ -C ₄ -alkyl; and R ^{36 is} H or R ³⁵ .

Preferably, A is a methylene or polymethylene group having 2 to 20 methylene units. Examples of suitable radicals R ²³ and R ²⁴ are 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, 2-ketopropyl, ethoxyethyl and propoxypropyl. The cyclic system can be either homocyclic, heterocyclic, condensed polycyclic or non-condensed polycyclic systems. Preferably, the ring system is carbo- or heteroaromatic, in particular carboaromatic. Examples of such polycyclic ring systems are condensed benzoic structures, such as naphthalene, anthracene, phenanthrene and pyrene, condensed non-benzoidic structures, such as azulene, indene, hydrindene and fluorene, uncondensed polycycles, such as diphenyl, heterocycles, such as quinoline, indole, dihydroindole, benzofuran, Coumarin, isocoumarin, benzthiophene, carbazole, diphenylene oxide and diphenylene sulfide, non-aromatic or partially saturated ring systems such as decalin, and three-dimensional structures such as α-pinene, camphene, bornylene, norborane, norbornene, bicyclooctane and bicyclooctene.

Another example of suitable polar nitrogen compounds are condensates of long-chain primary or secondary amines with carboxyl group-containing polymers.

The polar nitrogen compounds mentioned here are in the WO 00/44857 as well as in the cited references.

Suitable polar nitrogen compounds are also in the DE-A-198 48 621 of the DE-A-196 22 052 or the EP-B-398 101 described.

Preferred polar nitrogen compounds are ammonium salts and / or amides or imides obtainable by reacting at least one amine substituted with at least one hydrocarbyl radical with a carboxylic acid having 1 to 4 carboxyl groups or with a suitable derivative thereof. Preferred among these are ammonium salts and / or amides or imides of succinic acid, which is substituted by a long-chain hydrocarbon radical, in particular by a polyisobutyl radical.

The at least one cold flow improver comprises at least one copolymer of ethylene with at least one further ethylenically unsaturated monomer (a). With regard to preferred copolymers used according to the invention, reference is made to the statements made above.

Also suitable are mixtures of such copolymers (a) with at least one polar nitrogen compound (d).

In particular, the at least one cold flow improver (i) is a copolymer of ethylene with at least one alkenylcarboxylic acid ester or a copolymer of ethylene with an alkenylcarboxylic acid ester and a (meth) acrylic acid ester or a copolymer of ethylene with an alkenylcarboxylic acid ester and styrene and especially an ethylene / vinyl acetate copolymer.

In an alternatively preferred embodiment, the at least one cold flow improver (i) is a mixture of at least one copolymer of ethylene with at least one further ethylenically unsaturated monomer (a) with at least one polar nitrogen compound (d). With regard to suitable and preferred cold flow improvers (a) and (d), reference is made to the above statements.

The at least one solvent (ii) is a solvent for the at least one cold flow improver (i) and is selected from aliphatic and aromatic hydrocarbons and mixtures thereof. As a rule, solvents (mixtures) such as are customary for fuel additive packages are used. Examples include benzine fractions, kerosene, decane, pentadecane, toluene, xylene, ethylbenzene or commercial solvent mixtures, such as solvent naphtha, Shellsol® AB, Solvesso® 150, Solvesso® 200, Exxsol®, ISOPAR® and Shellsol® D types. Possibly It is also possible to use more polar solvents, for example higher alcohols having 4 to 14 carbon atoms, such as n-butanol, 2-ethylhexanol, decanol, isodecanol or isotridecanol, or higher ethers, such as di-n-butyl ether, or esters, which then act as solubilizers (Solubilizers) act.

• wenigstens ein weiteres Brennstofföladditiv, das ausgewählt ist unter Detergens-additiven, aschefreien Dispergatoren, Demulgatoren, Dehazern, Trägerölen, Cetanzahlverbesserern, Metalldeaktivatoren, Korrosionsinhibitoren, Antioxidantien, Schmierfähigkeitsverbesserern, Entschäumern, Antistatika, Stabilisatoren, Farbmarkern, Duftstoffen und Gemischen davon.

In a preferred embodiment of the invention, in addition to the components (i) and (ii), the at least two components to be mixed additionally comprise (iii)

• at least one other fuel oil additive selected from detergent-additive ashless dispersants, demulsifiers, dehazers, carrier oils, cetane improvers, metal deactivators, corrosion inhibitors, antioxidants, lubricity improvers, defoamers, antistatic agents, stabilizers, color markers, fragrances, and mixtures thereof.

1. (A) Mono- oder Polyaminogruppen mit bis zu 6 Stickstoffatomen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat;
2. (B) Nitrogruppen, gegebenenfalls in Kombination mit Hydroxylgruppen;
3. (C) Hydroxylgruppen in Kombination mit Mono- oder Polyaminogruppen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat;
4. (D) Carboxylgruppen oder deren Alkalimetall- oder Erdalkalimetallsalzen;
5. (E) Sulfonsäuregruppen oder deren Alkalimetall- oder Erdalkalimetallsalzen;
6. (F) Polyoxy-C₂-C₄-alkylengruppierungen, die durch Hydroxylgruppen, Mono- oder Polyaminogruppen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat, oder durch Carbamatgruppen terminiert sind;
7. (G) Carbonsäureestergruppen;
8. (H) aus Bernsteinsäureanhydrid abgeleiteten Gruppierungen mit Hydroxy- und/oder Amino- und/oder Amido- und/oder Imidogruppen; und/oder
9. (I) durch Mannich-Umsetzung von substituierten Phenolen mit Aldehyden und Mono- oder Polyaminen erzeugten Gruppierungen;

Preferably, the detergent additives are amphiphilic substances having at least one hydrophobic hydrocarbon radical having a number average molecular weight (M _n ) of from 85 to 20,000 and at least one polar moiety selected from:

1. (A) mono- or polyamino groups having up to 6 nitrogen atoms, at least one nitrogen atom having basic properties;
2. (B) nitro groups, optionally in combination with hydroxyl groups;
3. (C) hydroxyl groups in combination with mono- or polyamino groups, wherein at least one nitrogen atom has basic properties;
4. (D) carboxyl groups or their alkali metal or alkaline earth metal salts;
5. (E) sulfonic acid groups or their alkali metal or alkaline earth metal salts;
6. (F) polyoxy-C ₂ -C ₄ alkylene moieties terminated by hydroxyl groups, mono- or polyamino groups, wherein at least one nitrogen atom has basic properties, or terminated by carbamate groups;
7. (G) carboxylic acid ester groups;
8. (H) succinic anhydride-derived moieties having hydroxy and / or amino and / or amido and / or imido groups; and or
9. (I) by Mannich reaction of substituted phenols with aldehydes and mono- or polyamines generated groups;

The hydrophobic hydrocarbon radical in the above detergent additives, which provides the sufficient solubility in the fuel oil, has a number average molecular weight (M _n ) of 85 to 20,000, in particular from 113 to 10,000, especially from 300 to 5000. As a typical hydrophobic hydrocarbon radical, especially in connection with the polar groupings (A), (C), (H) and (I), longer-chain alkyl or alkenyl groups, in particular the polypropenyl, polybutenyl and polyisobutenyl radical having in each case M _n = 300 to 5000, in particular 500 to 2500, especially 700 to 2300, into consideration.

As examples of the above groups of detergent additives, the following are mentioned:
Mono- or polyamino groups (A) -containing additives are preferably polyalkylene mono- or polyalkene polyamines based on polypropene or conventional (ie with predominantly intermediate double bonds) polybutene or polyisobutene with M _n = 300 to 5000. If one goes in the preparation of the additives of polybutene or polyisobutene with predominantly central double bonds (usually in the beta and gamma position), the preparation route by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to the carbonyl or carboxyl compound and subsequent amination under reductive (hydrogenating) conditions , For amination here amines, such as. For example, ammonia, monoamines or polyamines, such as dimethylaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine, are used. Corresponding additives based on polypropene are especially in the WO 94/24231 described.

Further preferred monoamino groups (A) containing additives are the hydrogenation products of the reaction products of polyisobutenes having an average degree of polymerization P = 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described in particular WO-A-97/03946 are described.

Further preferred monoamino groups (A) -containing additives are the compounds obtainable from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the amino alcohols, as are described in particular in US Pat DE-A-196 20 262 are described.

Nitro groups (B), optionally in combination with hydroxyl groups, containing additives are preferably reaction products of polyisobutenes of average degree of polymerization P = 5 to 100 or 10 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as described in particular WO-A-96/03367 and WO-A-96/03479 are described. These reaction products are generally mixtures of pure nitropolyisobutenes (eg, α, β-dinitropolyisobutene) and mixed hydroxynitropolyisobutenes (eg, α-nitro-β-hydroxy polyisobutene).

Hydroxyl groups in combination with mono- or polyamino groups (C) -containing additives are in particular reaction products of polyisobutene epoxides, obtainable from polyisobutene preferably predominantly having terminal double bonds with Mn = 300 to 5000, with ammonia, mono- or polyamines, as they are in particular EP-A-476485 are described.

Carboxyl groups or their alkali metal or alkaline earth metal salts (D) containing additives are preferably copolymers of C ₂ -C ₄₀ olefins with maleic anhydride having a total molecular weight of 500 to 20,000, their carboxyl groups wholly or partially to the alkali metal or alkaline earth metal salts and a remainder the carboxyl groups are reacted with alcohols or amines. Such additives are in particular from the EP-A-307,815 known. Such additives are primarily for preventing valve seat wear and can, as in the WO-A-87/01126 described, be used with advantage in combination with conventional fuel detergents such as poly (iso) butenamines or polyetheramines.

Sulfonic acid groups or their alkali metal or alkaline earth metal salts (E) containing additives are preferably alkali metal or alkaline earth metal salts of a Sulfobernsteinsäurealkylesters, as described in particular in EP-A-639 632 is described. Such additives are primarily used to prevent valve seat wear and can be used to advantage in combination with conventional fuel detergents such as poly (iso) butenamines or polyetheramines.

Polyoxy-C ₂ -C ₄ -alkylene (F) containing additives are preferably polyether or polyetheramines, which by reaction of C ₂ -C ₆₀ -alkanols, C ₆ -C ₃₀ -alkanediols, mono- or di-C ₂ -C ₃₀ alkylamines, C ₁ -C ₃₀ -alkylcyclohexanols or C ₁ -C ₃₀ -alkylphenols with 1 to 30 mol of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group and, in the case of polyetheramines, by subsequent reductive amination with ammonia, Monoamines or polyamines are available. Such products are used in particular EP-A-310 875 . EP-A-356 725 . EP-A-700 985 and U.S. Patent 4,877,416 described. In the case of polyethers, such products also meet carrier oil properties. Typical examples of these are tridecanol or Isotridecanolbutoxylate, Isononylphenolbutoxylate and Polyisobutenolbutoxylate and propoxylates and the corresponding reaction products with ammonia.

Carboxylic ester groups (G) containing additives are preferably esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, in particular those having a minimum viscosity of 2 mm ² / s at 100 ° C, as in particular DE-A-38 38 918 are described. As mono-, di- or tricarboxylic acids, aliphatic or aromatic acids can be used, as ester alcohols or Polyols are especially long-chain representatives with, for example, 6 to 24 carbon atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of iso-octanol, iso-nonanol, iso-decanol and of isotridecanol. Such products also meet carrier oil properties.

Succinic anhydride derived groupings containing hydroxy and / or amino and / or amido and / or imido groups (H) containing additives are preferably corresponding derivatives of alkyl- or alkenyl-substituted succinic anhydride and especially the corresponding derivatives of polyisobutenyl succinic anhydride prepared by reacting Conventional or highly reactive polyisobutene with M _n = 300 to 5000 with maleic anhydride by thermal means or via the chlorinated polyisobutene are available. Of particular interest here are derivatives with aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine. The groups having hydroxyl and / or amino and / or amido and / or imido groups are, for example, carboxylic acid groups, acid amides of monoamines, acid amides of diamines or polyamines which, in addition to the amide function, still have free amine groups, succinic acid derivatives with a Acid and an amide, Carbonsäureimide with monoamines, Carbonsäureimide with di- or polyamines, which still have free amine groups in addition to the imide function, or diimides, which are formed by the reaction of di- or polyamines with two succinic acid derivatives. Such fuel additives are particularly in U.S. Patent 4,849,572 described.

By Mannich reaction of substituted phenols with aldehydes and mono- or polyamines produced groupings containing (I) additives are preferably reaction products of polyisobutene-substituted phenols with formaldehyde and mono- or polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or dimethylaminopropylamine. The polyisobutenyl-substituted phenols may be derived from conventional or highly reactive polyisobutene having M _n = 300 to 5,000. Such "polyisobutene-Mannich bases" are particularly in the EP-A-831 141 described.

Particularly preferred are detergent additives from group (H). These are preferably the reaction products of alkyl- or alkenyl-substituted succinic anhydrides, in particular of polyisobutenylsuccinic anhydrides, with amines. It goes without saying that these reaction products are obtainable not only when substituted succinic anhydride is used, but also when substituted succinic acid or suitable acid derivatives such as succinic acid halides or esters are used.

Particularly preferred detergent additives are polyisobutenyl-substituted succinimides, especially the imides with aliphatic polyamines. Especially preferred Polyamines are diethylenetriamine, tetraethylenepentamine and pentaethylenehexamine, with tetraethylenepentamine being particularly preferred. The polyisobutenyl radical has a number average molecular weight M _n of preferably 500 to 5000, particularly preferably 500 to 2000 and in particular about 1000.

It goes without saying that the detergent additives can be used alone or in combination with at least one of the aforementioned detergent additives.

Suitable mineral carrier oils are fractions obtained in petroleum processing, such as bright stock or base oils with viscosities such as from class SN 500-2000; but also aromatic hydrocarbons, paraffinic hydrocarbons and alkoxyalkanols. It is also useful as a "hydrocrack oil" known and obtained in the refining of mineral oil fraction (Vakuumdestillatschnitt with a boiling range of about 360 to 500 ° C, available from high pressure catalytically hydrogenated and isomerized and dewaxed natural mineral oil). Also suitable are mixtures of the abovementioned mineral carrier oils.

Examples of synthetic carrier oils are selected from: polyolefins (polyalphaolefins or polyinternalolefins), (poly) esters, (poly) alkoxylates, polyethers, aliphatic polyetheramines, alkylphenol-initiated polyethers, alkylphenol-initiated polyetheramines and carboxylic acid esters of long-chain alkanols.

Examples of suitable polyolefins are olefin polymers having M _n = 400 to 1800, especially based on polybutene or polyisobutene (hydrogenated or non-hydrogenated).

Examples of suitable polyethers or polyetheramines are preferably polyoxy-C ₂ -C ₄ -alkylene group-containing compounds which are obtained by reacting C ₂ -C ₆₀ -alkanols, C ₆ -C ₃₀ -alkanediols, mono- or di-C ₂ -C ₃₀ alkylamines, C ₁ -C ₃₀ -alkylcyclohexanols or C ₁ -C ₃₀ -alkylphenols with 1 to 30 mol of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group and, in the case of polyetheramines, by subsequent reductive amination with ammonia, Monoamines or polyamines are available. Such products are used in particular EP-A-310 875 . EP-A-356 725 . EP-A-700 985 and US-A-4,877,416 described. For example, as polyetheramines, poly-C ₂ -C ₆ alkylene oxide amines or functional derivatives thereof can be used. Typical examples of these are tridecanol or Isotridecanolbutoxylate, Isononylphenolbutoxylate and Polyisobutenolbutoxylate and propoxylates and the corresponding reaction products with ammonia.

Examples of carboxylic acid esters of long-chain alkanols are in particular esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols, as they are in particular in the DE-A-38 38 918 are described. As mono-, di- or tricarboxylic acids it is possible to use aliphatic or aromatic acids, especially suitable ester alcohols or polyols are long-chain representatives having, for example, 6 to 24 C atoms. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of isooctanol, isononanol, isodecanol and Isotridecanols, such as. As di (n- or iso-tridecyl) phthalate.

Other suitable carrier oil systems are described, for example, in DE-A-38 26 608 . DE-A-41 42 241 . DE-A-43 09 074 . EP-A-0 452 328 and EP-A-0 548 617 ,

Examples of particularly suitable synthetic carrier oils are alcohol-started polyethers with about 5 to 35, such as. B. about 5 to 30, C ₃ -C ₆ alkylene oxide, such as. B. selected from propylene oxide, n-butylene oxide and i-butylene oxide units, or mixtures thereof. Nonlimiting examples of suitable starter alcohols are long-chain alkanols or long-chain alkyl-substituted phenols, where the long-chain alkyl radical is in particular a straight-chain or branched C ₆ -C ₁₈ -alkyl radical. Preferred examples are tridecanol and nonylphenol.

Other suitable synthetic carrier oils are alkoxylated alkylphenols, as described in the DE-A-10 102 913.6 are described.

Preferred carrier oils are synthetic carrier oils, with polyethers being particularly preferred.

Suitable corrosion inhibitors are e.g. Succinic esters, especially with polyols, fatty acid derivatives, e.g. Oleic acid esters, oligomerized fatty acids, substituted ethanolamines, and products sold under the trade name RC 4801 (Rhein Chemie Mannheim, Germany) or HiTEC 536 (Ethyl Corporation).

Suitable demulsifiers are e.g. the alkali or alkaline earth salts of alkyl-substituted phenol and naphthalenesulfonates and the alkali or alkaline earth salts of fatty acids, as well as neutral compounds such as alcohol alkoxylates, e.g. Alcohol ethoxylates, phenol alkoxylates, e.g. tert-butylphenol ethoxylate or tert-pentylphenol ethoxylate, fatty acids, alkylphenols, condensation products of ethylene oxide (EO) and propylene oxide (PO), e.g. also in the form of EO / PO block copolymers, polyethyleneimines or polysiloxanes.

Suitable dehazers are, for example, alkoxylated phenol-formaldehyde condensates, such as, for example, the products NALCO 7D07 (Nalco) and TOLAD 2683 (Petrolite) available under the trade name.

Suitable antifoams are e.g. Polyether-modified polysiloxanes such as TEPHON 5851 (Goldschmidt), Q 25907 (Dow Corning) and RHODOSIL (Rhone Poulenc) available under the trade name.

Suitable cetane number improvers are e.g. aliphatic nitrates such as 2-ethylhexyl nitrate and cyclohexyl nitrate, and peroxides such as di-tert-butyl peroxide.

Suitable antioxidants are e.g. substituted phenols such as 2,6-di-tert-butylphenol and 2,6-di-tert-butyl-3-methylphenol, and phenylenediamines such as N, N'-di-sec-butyl-p-phenylenediamine.

Suitable metal deactivators are e.g. Salicylic acid derivatives such as N, N'-disalicylidene-1,2-propanediamine.

Component (iii) is preferably selected from antioxidants, corrosion inhibitors and antistatic agents.

When component (iii) is used in the process according to the invention, the individual additives are used in amounts which are customary in relation to component (i) for such packages.

When component (iii) is used in the process according to the invention, preferably all three components (i), (ii) and (iii) are mixed in the mixing pump.

Alternatively, in the process according to the invention, preferably only component (i) and component (ii) are mixed in the mixing pump.

Component (iii), in the case where only the components (i) and (ii) are mixed in the mixing pump according to the invention, can also be incorporated subsequently into the additive mixture produced according to the invention, for example by customary mixing or mixing, if the finished additive package also Component (iii) should contain. This is useful, for example, if the mixing in of component (iii) presents no special problems and a homogeneous package can be produced by conventional mixing methods, which has no handling disadvantages.

In the context of the present invention, fuel oils are understood as meaning liquid fuels and liquid fuels. Suitable fuel oils are gasolines and middle distillates. Middle distillates are preferably selected from diesel fuels, heating oil and turbine fuels.

The fuel oils are, for example, low-sulfur or high-sulfur petroleum refines or stone or lignite distillates, which usually have a boiling range of 150 to 400 ° C. The heating oils are preferably low-sulfur heating oils, for example those having a sulfur content of at most 0.1% by weight, preferably of at most 0.05% by weight, more preferably of at most 0.005% by weight, and in particular of at most 0.001% by weight. As examples of heating oil is especially called heating oil for domestic oil firing systems or fuel oil EL. The quality requirements for such heating oils are specified, for example, in DIN 51-603-1 (cf. Ullmann's Encyclopedia of Industrial Chemistry, 5th edition, Vol. A12, p. 617 ff .).

The diesel fuels are, for example, petroleum raffinates, which usually have a boiling range of 100 to 400 ° C. These are mostly distillates with a 95% point up to 360 ° C or even beyond. However, these may also be so-called "ultra low sulfur diesel" or "city diesel", characterized by a 95% point of, for example, a maximum of 345 ° C and a maximum sulfur content of 0.005 wt .-% or by a 95% point of, for example 285 ° C and a maximum sulfur content of 0.001 wt .-%.

In addition to the diesel fuels available through refining (petroleum), renewable diesel fuels, synthetic diesel fuels and blends of all these types of diesel fuel are also included in the concept of diesel fuels.

Synthetic fuels are generally petrol and diesel fuels, which are obtained by the Fischer-Tropsch process from various primary energy sources. The primary energy source is first converted to synthesis gas, which is then further reacted catalytically to the desired fuel type. The type of litigation determines whether synthetic diesel fuels or synthetic gasoline fuels are obtained. If one uses coal as the primary energy source, one speaks of a CTL fuel (CTL: coal-to-liquid); If natural gas is used, the end product is called GTL fuel (GTL: gas to liquid). Biomass is the starting material, it is a BTL fuel (BTL: biomass-to-liquid).

Renewable fuels are fuels that are produced from renewable raw materials, especially from plants. These include vegetable oils, biodiesel, bioethanol and also the BTL fuels already mentioned. Bioethanol is mainly used in gasoline engines and thus does not belong to the regenerative diesel fuels, but is counted among the renewable gasoline fuels. Biodiesel is generally understood to mean the lower alkyl esters of vegetable oils (or else animal fats), ie their C ₁ -C ₄ -alkyl esters, in particular their ethyl or methyl esters and especially their methyl esters. In Europe, the most widely used biodiesel is rapeseed oil methyl ester (RME). Biodiesel is produced by the transesterification of vegetable oils, which, above all consist of glycerol esters of long-chain fatty acids, with lower alcohols (C ₁ -C ₄ alcohols), in particular with methanol, but partially also with ethanol.

Preferred diesel fuels are diesel fuels obtained by refining, synthetic diesel fuels, the GTL, CTL and BTL diesel fuels, vegetable oils, biodiesel, and mixtures of these diesel fuel types.

Suitable turbine fuels, also referred to as jet fuels, jet fuels, jet fuel, aviation fuel or turbo-fuel, are for example fuels of the designation Jet A, Jet A-1, Jet B, JP-4, JP-5, JP-7, JP -8 and JP-8 + 100. Jet A and Jet A-1 are commercially available turbine fuel specifications based on kerosene. The associated standards are ASTM D 1655 and DEF STAN 91-91. Jet A and Jet A-1 have maximum freezing points of -40 ° C and -47 ° C, respectively, according to their specifications. Jet B is a further cut fuel based on naphtha and kerosene fractions. JP-4 is equivalent to Jet B. JP 4, 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 part, these names refer to formulations which already contain additives, such as corrosion inhibitors, anti-icing agents, static dissipators, etc. Preferred turbine fuels are Jet A, Jet A-1 and JP 8.

Conventional gasoline fuels are for example in Ullmann's Encyclopedia of Industrial Chemistry, 5th Ed. 1990, Vol. A16, p. 719 et seq , described. Due to their composition, petrol fuels have a lower boiling point range and a lower density compared to middle distillates.

The gasoline fuels can be both fuels for petrol engines in passenger cars and aviation fuel (leaded petrol with an RON of 100 to 130).

Preferred fuel oils are middle distillates, with diesel fuels and fuel oil being preferred. The diesel fuels may, as already mentioned, be refining synthetic (GTL, CTL) or regenerative diesel fuels or mixtures thereof.

Also described are additive mixtures which are obtainable by the process according to the invention. Reference is made to the statements made above with regard to suitable and preferred measures of the method according to the invention and the mixing components to be used and their quantitative ratios.

Finally, a fuel oil composition is described which contains an inventive additive mixture. On the comments made above regarding suitable and preferred measures of the method according to the invention, the mixing components to be used and their proportions and suitable and preferred fuel oils are referred to.

The fuel oil composition usually contains the additive mixture in conventional amounts, e.g. in an amount of 10 to 2000 ppm by weight, preferably from 20 to 1000 ppm by weight and in particular from 50 to 500 ppm by weight.

The use of mixing pumps in the process according to the invention gives additive mixtures which are superior to the additive mixtures prepared by conventional mixing methods in terms of their handling properties. The functional properties (for example cold flow-improving properties, such as CP, PP and CFPP of the fuel oils additized with the additive mixtures or intrinsic CP and PP) are essentially unchanged. "Substantially unchanged" means that the deviation is at most 10%, preferably at most 5%, more preferably at most 3%, and most preferably at most 1% (in comparison to additive mixtures prepared by conventional mixing methods). In particular, the resulting additive mixtures have a lower lower blending temperature (UET), greater storage stability and / or better filterability according to the SEDAB test described below as additive blends prepared by conventional blending techniques. Preferably, at least one of these parameters is improved by at least 10% over the additive mixtures of the prior art. Preferably, all three parameters are improved. Particularly preferably, all three parameters are improved by at least 10% compared to the additive mixtures of the prior art. If only a part of these parameters is improved, the other parameters are not or only slightly deteriorated compared to conventionally produced additive components. "Insignificant" means that the respective measured value is worse by at most 5%, preferably by at most 3%. Moreover, the process according to the invention makes it possible to completely and homogeneously mix components with very different viscosities or else components which are present in very different proportions in the mixture and thereby to obtain additive mixtures which are substantially more homogeneous than mixtures prepared by conventional mixing processes , In particular, the process according to the invention makes it possible to prepare additive mixtures of cold flow improvers in solvents, which are typically used in fuel oil additive packages, which have excellent handling properties. Cold flow improvers are generally highly viscous waxes which can not readily be incorporated homogeneously into such solvents.

The invention will now be described in more detail with reference to the following, non-limiting examples.

Examples 1. Preparation of the additive mixtures

Additive blends of a cold flow improver and a solvent were prepared and tested for their properties. In all experiments, a 50% polymer solution was prepared using as cold flow improver an ethylene / vinyl acetate copolymer having a vinyl acetate content of 30 wt .-% and a viscosity of 310 mm ² / s (at 120 ° C) and as a solvent Solvent naphtha was used. The temperature of the supplied polymer as well as the mixing temperature was in each case 90 ° C in each case. In all cases, the polymer solution formed was cooled by indirect cooling by means of a spiral heat exchanger (length: 1.8 m, diameter: 8 mm) in a water bath prior to discharge from the plant.

Reference Example 1

• Mixer: Zahnrranzdispergiermaschine the company Kinematica, type MT5000; Speed 20,000 rpm
• Throughput: 10 kg / h
• Average residence time: 19.8 s
• Temperature of the discharge: 48 ° C

Reference Example 2

• Mixer: Zahnrranzdispergiermaschine the company Kinematica, type MT5000; Speed 20,000 rpm
• Throughput: 10 kg / h
• Average residence time: 19.8 s
• Temperature of the discharge: 59 ° C

Reference Example 3

• Mixer: Zahnrranzdispergiermaschine the company Kinematica, type MT5000; Speed 6,000 rpm
• Throughput: 10 kg / h
• Average residence time: 19.8 s
• Temperature of the discharge: 59 ° C

Example 4

• Mixer: mixing pump from K-Engineering, type HMR 040; Speed 3,000 rpm
• Throughput: 10 kg / h
• Average residence time: 3.9 s
• Temperature of the discharge: 55 ° C

Example 5

• Mixer: mixing pump from K-Engineering, type HMR 040; Speed 3,000 rpm
• Throughput: 10 kg / h
• Average residence time: 3.9 s
• Temperature of the discharge: 61 ° C

Comparative Example 1

• Mixers: Static mixer from Sulzer, type SMX, diameter 8 mm, ratio length to diameter = 10
• Throughput: 9.6 kg / h
• Average residence time: 1.4 s
• Temperature of the discharge: 52 ° C

Comparative Example 2

• Mixers: Static mixer from Sulzer, type SMX, diameter 8 mm, ratio length to diameter = 10
• Throughput: 10 kg / h
• Average residence time: 1.3 s
• Temperature of the discharge: 49 ° C

2. Determination of the properties of the additive mixtures

The filterability and the minimum mixing temperature of the additive mixtures prepared above in a fuel oil were determined. In addition, the CFPP value (Cold Filter Plugging Point) of fuel oils additized with the additive mixtures was determined. Furthermore, the CP value (cloud point) and the PP value (pour point) of the cold flow improvers were determined. The CP value was determined according to ASTM D 2500, the CFPP value in the fuel oil was determined according to DIN EN 116 and the PP value was determined according to ASTM D 97. Storage stability, minimum mixing temperature (lower mixing temperature, UET) and filterability (SEDAB) were determined as described below.

The CFPP value was determined at each 400 ppm dosage of the additive mixtures prepared above in a fuel oil with the following specification: winter diesel fuel; Austria; CFPP = -14 ° C; CP = -11 ° C; Density = 833.6 kd / m ³ ; IBP = 167 ° C; FBP = 361 ° C; 90-20 = 117 ° C; 19.2% paraffins

The storage stability was determined optically. For this purpose, it was examined whether a phase separation, which can also be expressed in a turbidity, had occurred in the period considered.

SEDAB filtration test (ARAL house method)

For this purpose, a stainless steel vacuum filtration device (SM 16201 from Sartorius) with a 500 ml filter cup, a 2000 ml suction bottle and a membrane filter (order number 11304 50 N from Sartorius, 50 mm diameter, 0.8 μm pore size, 30 min at 90 ° C dried and stored dry) used.

The fuel oil is prefiltered to remove water, dirt and coker ingredients via a pleated filter. Per experiment 500 ml of the prefiltered fuel oil are filled into a 1000 ml mixing cylinder. 500 ppm of the additive mixture is added and then stored at room temperature for 16 h. Subsequently, the sample is homogenized by pivoting the mixing cylinder twice by 180 °. The membrane filter is inserted into the filtration unit and with the tap closed, the pressure is set to 200 mbar. The attached filter cup is filled with the homogenized sample (500 ml). The tap is opened and the filtration time is determined.

Samples that are completely filterable within 120 s are considered uncritical. Samples that are completely filterable within 120 s are considered "PASS"; it will be the Filtration time recorded. Samples where the filtration time is more than 120 s are considered "FAIL".

Determination of the minimum mixing temperature (UET)

The Mindestemmischtemperatur is particularly important for such refineries, mix the additives unheated in fuel oils or mix additives in unheated fuel oils. If the minimum mixing temperature of the additive is high, filter problems may occur after unheated mixing.

The minimum mixing temperature was determined by a modified SEDAB filtration test:
For this purpose, a stainless steel vacuum filtration device (SM 16201 from Sartorius) with a 500 ml filter cup, a 2000 ml suction bottle and a membrane filter (order number 11304 50 N from Sartorius, 50 mm diameter, 0.8 μm pore size, 30 min at 90 ° C dried and stored dry) used.

The fuel oil is prefiltered to remove water, dirt and coker ingredients via a pleated filter. Per experiment, 500 ml of the prefiltered and unadditized fuel oil are filled into a 1000 ml mixing cylinder and brought to the temperature to be tested. The tempered fuel oil is mixed with the undiluted 40 ° C warm additive mixture (500 ppm) and immediately homogenized by ten slight tilting of the mixing cylinder. The membrane filter is inserted into the filtration unit with the top of the filter and the pressure is set to 200 mbar when the tap is closed. The attached filter cup is filled with the homogenized sample (500 ml). The tap is opened and the filtration time is determined.

Samples that are completely filterable within 120 s are considered "PASS"; the filtration time at the given temperature is recorded. Samples in which the filtration time is more than 120 s are considered "FAIL"; The residual volume, which is still contained in the filter cup after 120 seconds, is determined. For such samples, the temperature of the fuel oil is increased by 5 ° C and the filtration time is again determined. The temperature increase by 5 ° C in each case is repeated until the sample is completely filterable within 120 s; the filtration time is recorded at the appropriate temperature. Conversely, for samples which are completely filterable within 120 s, the temperature of the fuel oil is successively lowered by 5 ° C until the sample is no longer completely filterable within 120 s. The minimum temperature value of 10 ° C should not be undercut.

The UET was determined at a dosage of the 40 ° C warm additive of 500 ppm in a fuel oil with the following specification:
Diesel fuel; Germany; CFPP = -13 ° C; CP = -12.2 ° C, density = 835.5 kg / m ³ ; IBP = 206 ° C; FBP = 343 ° C; 90-20 = 74 ° C; 22.6% n-paraffins.
The transit time of the unadditierten fuel was at 10 ° C 74 s.

The results are listed in the table below. table example Lead time ¹ [s] Shelf life ² UET [° C] CFPP [° C] PP [° C] FG ³ [%] 1 78 0 30 -21 15 49 2 87 + 30 -22 15 49 3 83 + 30 -21 15 49 4 55 + 25 -23 12 50 5 57 + 25 -24 12 55 cf. 1 > 120 - 35 -22 15 49 Vgl.2 110 - 35 -23 15 50 ¹ Filterability according to SEDAB test
² + = more than 6 months; 0 = 6 months; - = less than 6 months
³ FG = solids content; determined by evaporation of volatiles at elevated temperature and reduced pressure
Examples 1 to 3 are reference examples.

Claims (5)

1. A process for producing additive mixtures for fuel oils, in which at least two components of the additive mixture are mixed in a mixer selected from mixing pumps, wherein the at least two components of the additive mixture comprise

   (i) at least one cold flow improver and

   (ii) at least one solvent;

   wherein the cold flow improver is selected from copolymers of ethylene with at least one further ethylenically unsaturated monomer selected from alkenylcarboxylic esters, (meth)acrylic esters, styrene, styrene derivatives and olefins other than ethylene, and the solvent is selected from aliphatic and aromatic hydrocarbons and mixtures thereof.
2. The process according to claim 1, wherein the further ethylenically unsaturated monomer comprises vinyl acetate.
3. The process according to any of the preceding claims, wherein the at least one cold flow improver also comprises at least one polar nitrogen compound, the nitrogen compound being ammonium salts and/or amides or imides obtainable by the reaction of at least one amine substituted with at least one hydrocarbon radical with a carboxylic acid having from 1 to 4 carboxyl groups or with a suitable derivative thereof.
4. The process according to any of the preceding claims, wherein the at least two components of the additive mixture further comprise

   (iii) at least one further fuel oil additive which is selected from detergent additives, ashless dispersants, demulsifiers, dehazers, carrier oils, cetane number improvers, metal deactivators, corrosion inhibitors, antioxidants, lubricity improvers, defoamers, antistats, stabilizers, color markers, fragrances and mixtures thereof.
5. The process according to any of the preceding claims, wherein the mean mixing time is at most 120 seconds.