EP1923453A1 - Additives and use thereof as a solubilizing agent in fuels - Google Patents

Abstract

Use of a composition (I) comprising 1-8C alkyl ester and partial glyceride, where the glycerin content of free glycerin is up to 2 wt.%, as additive for the improvement of solubility of water and/or alcohol in fuel composition, is claimed. An independent claim is included for a fuel composition comprising: 60-99 wt.% of diesel; 0.5-20 wt.% (preferably 2-15 wt.%) of (I); 0.5-20 wt.% of ethanol; and 0-1% of additional water (in addition to the water content in the additive or in ethanol).

Description

The invention relates to the technical field of fuel additives. It relates to compositions containing fatty acid esters and partial glycerides and their use as solubilizers in ethanol-containing fuel compositions, especially diesel fuel.

In hydrocarbons, such as gas oils, fuel oils, gasoline, diesel, kerosene, etc., numerous additives are used. Thus, in addition to additives for corrosion protection and lubricity also flow improvers or compounds are known which improve the emission levels of gases such as CO, CO ₂ or NO _x . The addition of ethanol to diesel can reduce CO, NO _x and particulate matter levels. The problem with adding ethanol to diesel is the limited solubility of ethanol in diesel. The biggest problem is the very poor solubility of water or hydrous ethanol in diesel. It comes even with traces of water in ethanol-diesel mixtures to a separation and phase separation. Since diesel is highly hygroscopic and some traces of water in the tanks, it can be particularly easy to come to an undesirable separation.

Now, additives which allow the solution of water in fuel and counteract a phase separation are known in principle. From the WO 98/17745 For example, a composition comprising 25% by volume of a diethanolamide, 50% by volume of an ethoxylated alcohol and 25% by volume of a 7 mole ethoxylated C-14 fatty acid is concretely known. This additive serves to improve the solubility of ethanol in diesel, which, for example, leads to a reduction in the emissions of CO ₂ and CO and NO _x in the combustion of the additized fuel. In the WO 02/38709 are described fuel compositions which are free of alkanolamides and contain certain selected additives which are selected from ethoxylated and / or propoxylated alcohols or esters or from polyols or their fatty acid esters.
However, as before, there is a need to achieve a solution of ethanol in fuel, preferably in diesel by using as simple as possible, inexpensive additives. Another goal remains, a noticeable reduction in gaseous reaction products, in particular NO _x and CO or CO ₂ to achieve or improve existing additives in their effectiveness.

The object of the presently described invention has now been to effectively prevent the occurring during the addition of ethanol to fuels phase separation or segregation by the water content. The additives are also said to be useful in fuels according to the above-cited EU directive on biofuels application.

The invention relates to the use of a composition comprising (a) alkyl esters having an alkyl radical containing 1 to 8 carbon atoms and (b) partial glycerides having a glycerol content of free glycerol of not more than 2 wt .-% based on the total amount of the composition, as an additive for improving the solubility of water and / or alcohols in fuel compositions.
Thus, these additives have a solvent effect between non-aqueous at room temperature (= 21 ° C) liquid hydrocarbons and polar liquids such as alcohols and especially water.

For the purposes of this application, fuel compositions are understood as all energy-supplying operating materials whose free combustion energy is converted into mechanical work. The propellants in the context of the present invention are water-insoluble and can not be mixed with water without auxiliary means.
These include all types of liquid at room temperature and normal pressure motor and aviation fuels. Motor fuels, eg for car or truck engines, usually contain hydrocarbons, for example gasoline or higher-boiling petroleum fractions. The fuel compositions according to the invention are preferably diesel oil. This includes both road use such as diesel for engines and non-road use such as fuel oil, tractor oil, diesel diesel for mobile diesel engines, marine bunker oils or the like.
Diesel fuels are obtained from gas oil by cracking or from tars recovered from the carbonization of lignite or coal. Diesel fuels are flame retardant mixtures of liquid hydrocarbons used as fuels for constant pressure or Burner engines (diesel engines) are used and consist mainly of paraffins with admixtures of olefins, naphthenes and aromatic hydrocarbons. Their composition is inconsistent and depends especially on the manufacturing method. Typical products have a density between 0.83 and 0.88 g / cm ³ , a boiling point between 170 and 360 ° C and flash points between 70 and 100 ° C. Particularly preferred is the use of the additives according to the invention in diesel fuels which contain so-called biofuels according to European Directive 2003/30 / EC. The European Parliament has adopted Article 3.1 (b) of Directive 2003/30 / EC; that all diesel fuels contain 2% biofuel from 31.12.2005. This share should rise to 5.75% by 31.12.2010. Which biofuel is added is up to the manufacturers. In this directive, bio-fuel is defined in Article 2.2 as follows: bio-ethanol, rapeseed oil methyl ester (RSME), biogas, biomethanol, biodimethyl ether, biohydrogen, synthetic biofuels and pure vegetable oils.

The compositions used according to the invention are already known as such.
Reference is made to the WO 2006/077023 A2 the applicant in which the additives are described in full. However, there is no description of the specific use as a solubilizer, which is the subject of the present application.

For solubilization, preference is now given to using those compositions which have a maximum glycerol content of 1.3% by weight and more preferably of 1.0% by weight, amounts given by evaluation by area percent in the GC analysis and Values for glycerin need to be calibrated due to the strong absorption. Particularly preferred are compositions which are free of glycerol.

In a particular embodiment, the composition contains methyl and / or ethyl esters as alkyl esters. A further preferred embodiment relates to a composition as described above having a partial glyceride content of at least 10% by weight, and / or a triglyceride content of not more than 5% by weight and / or an acid number of not more than 5 based on the total amount of the composition. Preference is given to a monoglyceride content of at least 25 wt .-%.

In a further preferred embodiment, the composition contains methyl and / or ethyl esters, monoglycerides and diglyceride, preferably in proportions of: Methyl and / or ethyl esters 30-70% by weight, preferably 55-60% by weight monoglyceride 10-35% by weight, preferably 25-33% by weight diglyceride 1-30% by weight, preferably 1-20% by weight

The evaluation of the percentages by weight is carried out in a conventional manner by the area percent in the GC analysis. The information

Another embodiment relates to compositions in which both the alkyl esters (a) and the partial glycerides (b) are fatty acid esters of saturated or unsaturated, linear or branched fatty acids having an alkyl radical having 8 to 22 carbon atoms.
Particularly preferred for the purposes of the invention are in this case those fatty acid esters which can be obtained from vegetable oils such as linoleate, oleate, palmitate, stearate and / or pelargonate. Unsaturated representatives are, for example, laurolein, myristolein, palmitoleic, petroselaidin, oil, elaidin, ricinole, linoleic, linolaidin, linolenic gadolein, arachidone and erucic acid esters. Mixtures of the methyl esters and / or ethyl esters of these acids are also suitable. The esters based on unsaturated fatty acids may be particularly preferred.

Preferred oils for obtaining the fatty acid esters are sunflower oil, rapeseed oil, thistle oil, soybean oil, linseed oil, peanut oil, tallow, olive oil, castor oil, palm oil, palm oil fractions such as palm olein or palm stearin, yatropha oil, coconut oil or palm kernel oil. Particularly preferred are those compositions which are based on rapeseed oil fatty acids in the alkyl ester as in the glyceride component.

Peanut oil contains on average (based on fatty acid) 54% by weight of oleic acid, 24% by weight of linoleic acid, 1% by weight of linolenic acid, 1% by weight of arachidic acid, 10% by weight of palmitic acid and 4% by weight of stearic acid. The melting point is 2 to 3 ° C. Linseed oil typically contains 5% by weight of palmitic, 4% by weight of stearic, 22% by weight of oil, 17% by weight of linoleic acid and 52% by weight of linolenic acid. The iodine number is in the range 155 to 205, which is saponification number 188 to 196 and the melting point is about - 20 ° C. Olive oil contains predominantly oleic acid. Palm oil contains as fatty acid components about 2 wt .-% myristic, 42 wt .-% palmitane, 5 wt .-% stearic, 41 wt .-% oil, 10 wt .-% linoleic acid. Rapeseed oil typically contains about 48% by weight of erucic acid, 15% by weight of oleic acid, 14% by weight of linoleic acid, 8% by weight of linolenic acid, 5% by weight of icosenoic acid, 3% by weight of palmitic acid, 2% by weight of fatty acid components % Hexadecenoic acid and 1% by weight docosadienoic acid. Rapeseed oil from new breeding is enriched in terms of unsaturated components. Typical fatty acid moieties here are erucic acid 0.5% by weight, oleic acid 63% by weight, linoleic acid 20% by weight, linolenic acid 9% by weight, icosenoic acid 1% by weight, palmitic acid 4% by weight, hexadecenoic acid 2 Wt .-% and docosadienoic 1 wt .-%. Castor oil consists of 80 to 85 wt .-% of the glyceride of ricinoleic acid, besides about 7 wt .-% glycerides of the oil, to 3 wt .-% glycerides of linoleic and about 2 wt .-% of the glycerides containing palmitic and stearic acid. Soybean oil contains 55 to 65 wt .-% of total fatty acids polyunsaturated acids, especially linoleic and linolenic acid. Similarly, the situation with sunflower oil, whose typical fatty acid spectrum, based on total fatty acid looks like this: about 1 wt .-% myristic, 3 to 10 wt .-% palmitic, 14 to 65 wt .-% of oil and 20 bis 75% by weight of linoleic acid. All the above information on the fatty acid moieties in the triglycerides are known to be dependent on the quality of the raw materials and therefore may vary in number.

The fatty acid composition in the mixture results from the particular native fatty acid composition of the vegetable oil used and the particular quality of the raw material from which the methyl and / or ethyl esters and the monoglycerides are prepared.

The compositions according to the invention are preferably used in fuels which either additionally contain water or alcohols, preferably short-chain alcohols, such as methanol, ethanol, propanol or butanol, and more preferably contain both water and the alcohol. Preferred alcohols are ethanol or butanol, in particular ethanol being preferred.

The additive is contained in the fuel in amounts of at least 0.01% by weight, preferably in amounts of from 0.1 to 25% by weight and in particular in amounts of from 0.5 to 20% by weight. In this case, preference is again given to those mixtures which are typically 60 to 99% by weight. Diesel fuel, 0.5 to 20% by weight (preferably 2 to 15% by weight) of the compositions described above, 0.5 to 20% by weight of ethanol and 0 to 1% by weight of additional water (in addition to the water content in the additive or in the alcohol). The ethanol can also be replaced by butanol.

Claimed are also fuel compositions containing the above additives, wherein the fuel compositions must contain at least diesel and ethanol (or butanol, or mixtures of ethanol with butanol) side by side, and possibly even water. Preference is given to those fuel compositions which contain 60 to 99% by weight of diesel, 0.5 to 20% by weight (preferably 2 to 15% by weight) of the composition according to the description of claims 1 to 8 as an additive, 0, 5 to 20 wt .-% ethanol and 0 to 1% additional water - in addition to the water content in the additive or in the ethanol contained. The total water content (ie water content of additives and the alcohol plus any added water) of the fuel according to the invention should preferably be in the range of 0 to 5 wt .-% and particularly preferably in the range of 0.1 to 2.5 wt .-%. Further preferred are those fuels which contain less than 2 wt .-% total water, and preferably less than 1 wt .-% water.

Additives which may additionally be used with the compositions of the present invention are preferably selected from the group consisting of conductivity improvers, cetane improvers, CFPP / CP improvers, defoamers, lubricity improvers, corrosion inhibitors and dehazers. These are used in the usual concentrations, ie preferably in amounts of 0.001 to 15 wt .-%, with amounts of 0.001 to 5, 0 and in particular up to a maximum of 1.0 wt .-% may be preferred.

Examples Example 1: Enzymatic Synthesis of Ethanol-Containing Ethyl Ester Partial Glyceride Mixture

The preparation of Examples 1 and 2 is carried out according to the teaching of the above cited according to WO 2006/077023 A2 , A total of 1600 kg of refined rapeseed oil, 640 kg of ethanol, 600 ml of 1 M NaOH, 71% water and 250,000 U lipase (esterase from Thermomyces, unit information according to the manufacturer) are added to 1 kg rapeseed oil in a 4000 l reactor. The mixture is stirred for 40 h, then the mixture is heated with stirring to 80 ° C and stirred for 2 h at 80 ° C, the container remains closed, so that no ethanol can escape. It is then cooled to 50 ° C and filtered through a drum filter with 10 kg Celatom FW 14. The product is bottled and stored at room temperature.
Conclusion: 2200 kg of product are obtained with a yield of 98%.

Example 2: Preparation of distilled ethyl ester partial glyceride mixture

A total of 1600 kg of refined rapeseed oil, 640 kg of ethanol, 600 ml of 1 M NaOH, 71% water and 250,000 U lipase (esterase from Thermomyces, unit information according to the manufacturer), based on 1 kg rapeseed oil, are introduced into a 4000 l reactor. The mixture is stirred for 40 h, then the mixture is heated with stirring to 120 ° C. Vacuum is placed on the reactor and the ethanol - water mixture is withdrawn from the reactor. The vacuum is slowly lowered until no more ethanol escapes from the batch. It is then cooled to 50 ° C and filtered through a drum filter with 10 kg Celatom FW 14. The product is bottled and stored at room temperature.
Conclusion: 1742 kg of product and 470 kg of distillate are obtained with a yield of 98%.

Example 3: Analysis of the experimental products from Examples 1 and 2

The analyzes listed in the table were carried out with the test products from Examples 1 and 2. Product from Example 1 (undistilled) Product from Example 2 (distilled) Key figures hydroxyl about 318 - 335 107 iodine Value 83 105 peroxide 9.1 9.6 acid number 1.9 2.7 saponification 136 173 density 0.875 g / ml 0.9 g / ml color values Lovibond 5-1 / 4 19 / 2.3 35 / 3.2 Lovibond 1 2.0 / 0.6 3.5 / 0.8 Gardner 2.6 3.9 trace analysis nitrogen <20 mg / kg <20 mg / kg sulfur <2 mg / kg <2 mg / kg sodium 8 mg / kg 10 mg / kg iron 0.4 mg / kg 0.7 mg / kg phosphorus <3 mg / kg <3 mg / kg composition water content 0.3 0.01 Glycerin free 0.20% 0.30% Glycerol bound 6.80% 9.00% ethanol 21.90% 0.20% ethyl ester 41.00% 55.50% monoglycerides 23.00% 32.20% diglycerides 13.00% 11.40% triglycerides <1% <1% fatty acid spectrum palmitic 5.20% 4.80% stearic acid 1.30% 1.30% oleic acid 58.30% 60.20% linoleic acid 21.10% 20.80% linolenic 8.80% 8.30% Conclusion: The test products are a mixture consisting mainly of ethyl esters and monoglycerides based on the fatty acid composition of rapeseed oil. In lower proportions diglycerides are included, secondary components are fatty acids and triglycerides. The non-distilled approach contains additional ethanol and small amounts of water. The test products are of good color, which corresponds to that of the oils used. The contents of organic and inorganic substances are low. Based on the glycerol analysis can be seen the glycerol of the triglyceride is almost completely bound in the form of the partial glycerides and less than 5% of the glycerol is in free form.

Example 4 Stability of the Experimental Products of Examples 1 and 2

The products of Example 1 and Example 2 were stored for 3 months at room temperature in sealed drums. Product out Product out Product out Product out Example 1 (undistilled) example 1 Example 2 (distilled) Example 2 composition after synthesis after 3 months after synthesis after 3 months ethyl ester 41.00% 40.10% 55.50% 55.00% monoglycerides 23.00% 22.30% 32.20% 31.20% diglycerides 13.00% 13.30% 11.40% 12.00% triglycerides <1% 1.90% <1% 0.90% Glycerine free (titr.) 0.20% 0.25% 0.30% 0.50% Glycerine free (GC) 1.10% 0.70% 0.90% 0.90% Key figures after synthesis after 3 months after synthesis after 3 months Acid value 1.9 1.9 2.7 2.8 POV 9.1 9.6 Lovibond 2.0 / 0.6 1.9 / 0.6 3.5 / 0.8 3.0 / 0.8 Gardner 2.6 2.6 3.9 3.6 Conclusion: The products are sufficiently storage stable for use as diesel additive or fuel additive to diesel.

Example 5 Water Absorption Capacity of Ethanol-Diesel Mixtures in the Presence of Experimental Products of Example 1 or 2 or in the Presence of FAME (Fatty Acid Methylester - Rape Methyl Ester)

Mixtures are prepared from 170 g of diesel, 10 g of 99.9% strength ethanol and 20 g of undistilled test product from Example 1, distilled test product from Example 2 or biodiesel (FAME - fatty acid methyl ester - rapeseed methyl ester). "Blank", as the comparison mixture is a mixture of 190 g of diesel and 10 g of 99.9% ethanol. The mixtures are titrated with water while stirring until turbidity appears. This point gives the solubility limit of water in the system.
Results: Water content [%] Product from Example 1 (undistilled) 0.22% Product from Example 2 (distilled) 0.30% FAME 0.15% bright 0.14% Conclusion: Biodiesel (FAME) has no significant effect on water solubility in ethanol - diesel blends. In contrast, products of Example 1 and 2 - admixtures produce a significantly increased water solubility in the system diesel-ethanol. With distilled product from Example 2, a water solubility is achieved under the set conditions, which is above the water content of azeotropic ethanol in the ethanol concentration used. The water content of azeotropic ethanol is 0.20%.

Example 6 Solubility Behavior of 96 Vol .-% Alcohol in Diesel in the Presence of Experimental Products of Example 1 or 2 at 25 ° C

There were produced 82 different mixtures consisting of 30 g total weight. The mixtures consisted of different combinations of diesel, 96% aqueous ethanol and either distilled product of Example 1, distilled product of Example 2 or biodiesel (rapeseed methyl ester). The mixtures were placed in 50 ml Falcon tubes, mixed well and stored sealed at 25 ° C for 1 week. After 1 week, it was checked whether the system was clear and single-phase or whether a segregation had taken place. Two-phase as well as multi-phase and cloudy samples without clear phase boundary were evaluated as demixed. The phase boundary between the one- and two-phase range as a function of the ethanol and the test products or biodiesel concentration is shown in the form of diagrams in Figure 1a (product according to Example 2), 1b (product according to Example 1) and 1c (biodiesel).
Conclusion: The solubility of 96 vol .-% ethanol in diesel at 25 ° C is below 0.5%. Addition of biodiesel to the system can only insignificantly improve ethanol solubility. In contrast, test products according to Example 1 or 2 distilled and undistilled significantly increase the ethanol solubility in ethanol-diesel mixtures. In particular, product after Example 2 - distilled, can hold large amounts of 96% ethanol for one week stable in solution over a period of at least 1 week.

Example 7 Solubility Behavior of 96 Vol .-% Alcohol in Diesel in the Presence of Experimental Products of Example 1 or 2 at 8 ° C

There were produced 82 different mixtures consisting of 30 g total weight. The mixtures consisted of different combinations of diesel, 96% aqueous ethanol and either distilled product of Example 1, distilled product of Example 2 or biodiesel (rapeseed methyl ester). The mixtures were placed in 50 ml Falcon tubes, mixed well and stored sealed at 8 ° C for 1 week. After 1 week, it was checked whether the system was clear and single-phase or whether a segregation had taken place. Two-phase as well as multi-phase and cloudy samples without clear phase boundary were evaluated as demixed. The phase boundary between the one- and two-phase range as a function of the ethanol and the experimental products or biodiesel concentration is shown in the form of diagrams in Figure 2a (product according to Example 2), 2b (product according to Example 1) and 2c (biodiesel).
Conclusion: The solubility of 96 vol .-% ethanol in diesel is at 8 ° C below 0.5%. Addition of biodiesel to the system can only insignificantly improve ethanol solubility. In contrast, test products according to Example 1 or 2 distilled and undistilled significantly increase the ethanol solubility in ethanol-diesel mixtures. In particular, product according to Example 2 - distilled can hold large amounts of 96 vol .-% ethanol over a period of at least 1 week single-phase stable in solution.

Example 8 Solubility Behavior of 96 Vol .-% Alcohol in Diesel in the Presence of Experimental Products of Example 1 or 2 at -17 ° C

There were produced 82 different mixtures consisting of 30 g total weight. The mixtures consisted of different combinations of diesel, 96% aqueous ethanol and either distilled product of Example 1, distilled product of Example 2 or biodiesel (rapeseed methyl ester). The mixtures were added for better cold stability with 0.5% flow improver (Liqui Moli Diesel flow fit), in 50 ml Falcon tubes given, mixed well and stored sealed at -17 ° C for 1 week. After 1 week, it was checked whether the system was clear and single-phase or whether a segregation had taken place. Two-phase as well as multi-phase and cloudy samples without clear phase boundary were evaluated as demixed. The phase boundary between the one- and two-phase range as a function of the ethanol and the test products or biodiesel concentration is shown in the form of diagrams in Figure 3a (product according to Example 2), 3b (product according to Example 1) and 3c (Biodiesel).
Conclusion: The solubility of 96% ethanol in diesel at -17 ° C is below 0.5%. Addition of biodiesel to the system can not detectably improve ethanol solubility. In contrast, test products according to Example 1 or 2 distilled and undistilled significantly increase the ethanol solubility in ethanol-diesel mixtures. In particular, product according to Example 2 - distilled can hold larger amounts of 96 vol .-% ethanol over a period of at least 1 week single-phase stable in solution.

Example 9 Solubility Behavior of 99 Vol .-% Alcohol in Diesel in the Presence of Experimental Products of Example 2 at 8 ° C

There were 54 different mixtures consisting of 30 g total weight produced. The mixtures consisted of different combinations of diesel, 99% aqueous ethanol and either distilled product from example 2 or biodiesel (rapeseed methyl ester). The mixtures were placed in 50 ml Falcon tubes, mixed well and stored sealed at 8 ° C for 1 week. After 1 week, it was checked whether the system was clear and single-phase or whether a segregation had taken place. Two-phase as well as multi-phase and cloudy samples without clear phase boundary were evaluated as demixed. The phase boundary between the one- and two-phase region as a function of the ethanol and the test product or biodiesel concentration is shown in the form of diagrams in FIGS. 4a and 4b .
Conclusion: The solubility of 99 vol.% Ethanol in diesel at 8 ° C is about 4%. Biodiesel has a positive effect on ethanol solubility in this system. Compared to this, the test product according to Example 2 - distilled has a much stronger effect on the alcohol solubility. Up to 20% ethanol can be solved stable over a week, if 10% test product according to Example 2 distilled to be mixed system of diesel and ethanol.

Example 10 Solubility Behavior of 99 Vol .-% Alcohol in Diesel in the Presence of Experimental Products of Example 2 at -17 ° C

There were 54 different mixtures consisting of 30 g total weight produced. The mixtures consisted of different combinations of diesel, 99% by volume aqueous ethanol and either distilled product from Example 2 or biodiesel (rapeseed methyl ester). The mixtures were added for better cold stability with 0.5% flow improver (Liqui Moli Diesel flow fit), placed in 50 ml Falcon tubes, well mixed and sealed at -17 ° C for 1 week. After 1 week, it was checked whether the system was clear and single-phase or whether a segregation had taken place. Two-phase as well as multi-phase and cloudy samples without clear phase boundary were evaluated as demixed. The phase boundary between the one- and two-phase range as a function of the ethanol and the test product or biodiesel concentration is shown in the form of diagrams in FIGS. 5a and 5b.
Conclusion: The solubility of 99 vol .-% ethanol in diesel is at -17 ° C below 2%. Biodiesel has a positive effect on ethanol solubility in this system. Compared to this, the test product according to Example 2 - distilled has a much stronger effect on the alcohol solubility. Up to 10% ethanol can be stably dissolved over a week, when 10% test product according to Example 2 - distilled mixed to the system of diesel and ethanol.

Example 11: Solubility Behavior of 99.9 Vol .-% Alcohol in Diesel in the Presence of Experimental Products of Example 2 at 8 ° C

There were 34 different mixtures consisting of 30 g total weight produced. The mixtures consisted of different combinations of diesel, 99% by volume aqueous ethanol and either distilled product from Example 2 or biodiesel (rapeseed methyl ester). The mixtures were placed in 50 ml Falcon tubes, mixed well and stored sealed at 8 ° C for 1 week. After 1 week, it was checked if the system was clear and single-phase or whether a demixing had taken place. Two-phase as well as multi-phase and cloudy samples without clear phase boundary were evaluated as demixed. The phase boundary between the one- and two-phase range as a function of the ethanol and the test product or biodiesel concentration is shown in the form of diagrams in FIGS. 6a and 6b.
Conclusion: The solubility of 99.9 vol.% Ethanol in diesel at 8 ° C is between 10% and 15%. Biodiesel has a positive effect on ethanol solubility in this system. Compared to this, the test product according to Example 2 - distilled has a much stronger effect on the alcohol solubility. Up to 25% ethanol can be stably dissolved over a week when 5% test product according to Example 2 - distilled mixed to the system of diesel and ethanol.

Example 12 Solubility Behavior of 99.9 Vol .-% Alcohol in Diesel in the Presence of Experimental Products of Example 2 at -17 ° C

There were 34 different mixtures consisting of 30 g total weight produced. The mixtures consisted of different combinations of diesel, 99.9% by volume aqueous ethanol and either distilled product from Example 2 or biodiesel (rapeseed methyl ester). The mixtures were added for better cold stability with 0.5% flow improver (Liqui Moli Diesel flow fit), placed in 50 ml Falcon tubes, mixed well and sealed at -17 ° C for 1 week. After 1 week, it was checked whether the system was clear and single-phase or whether a segregation had taken place. Two-phase as well as multi-phase and cloudy samples without clear phase boundary were evaluated as demixed. The phase boundary between the one- and two-phase range as a function of the ethanol and the test product or biodiesel concentration is shown in the form of diagrams in FIGS. 7a and 7b.

Conclusion: The solubility of 99.9 vol .-% ethanol in diesel is at -17 ° C between 5% and 10%. Biodiesel has a positive effect on ethanol solubility in this system. In comparison, ECO diesel distilled has a much stronger effect on the alcohol solubility. Up to 20% ethanol can be solved stable over a week, when 10% trial product according to Example 2 are mixed to the system of diesel and ethanol.

Summary of the results for Examples 6-12

Ex. T [° C] Addition of Max. Solubility of ethanol in diesel [%] (Ex 6-8 = 96 vol.% Ethanol, Ex. 9-10 = 99 vol.% Ethanol; Ex 11-12 = 99.9 vol. % ethanol) Product Ex. 1 [%] Product Ex. 2 [%] Biodiesel [%] Without addition With trial product With biodiesel Example 1 Ex. 2 6 25 18% 15% 19% <0.5% 7% 10% 1% 7 8th 19% 15% 19% <0.5% 6% 10% 1 % 8th -17 19% 17% 19% <0.5% 6% 8th% <0.5% 9 8th 10% 15% 4% 20% 12% 10 -17 10% 15% <2% 10% 5% 11 8th 5% 10% 10-15% 25% 20% 12 -17 10% 10% 5-10% 20% <18% The table summarizes the effects on the solubility of ethanol in diesel with the addition of certain amounts of test product according to Example 1, Example 2 or comparative after the addition of biodiesel. In comparison with biodiesel, surprisingly higher solubilities of ethanol in diesel could be found, especially at temperatures of 8 ° C. or 25 ° C., when test products according to Example 2 (distilled) were added in amounts of up to 15%.

Claims (14)

Use of a composition comprising (a) alkyl esters having an alkyl radical containing 1 to 8 carbon atoms, (b) partial glycerides, characterized in that it has a glycerol content of free glycerol of not more than 2% by weight, based on the total amount of the composition, as an additive to Improving the solubility of water and / or alcohols in fuel compositions. Use according to claim 1, characterized in that the composition contains as component (a) methyl and / or ethyl esters. Use according to at least one of claims 1 to 2, characterized in that the composition contains a Partialglyceridgehalt of at least 10 wt .-%, based on the total amount of the composition. Use according to at least one of claims 1 to 3, characterized in that the composition contains a triglyceride content of at most 5 wt .-%, based on the total amount of the composition. Use according to at least one of claims 1 to 4, characterized in that the composition has an acid number of at most 5. Use according to at least one of claims 1 to 5, characterized in that the alkyl esters, monoglycerides and diglycerides in the composition in proportions of alkyl esters 30-70% by weight monoglyceride 10-35% by weight diglyceride 1-30% by weight containing. Use according to at least one of claims 1 to 6, characterized in that the alkyl esters and partial glycerides in the composition of saturated or unsaturated, linear or branched fatty acids having 8 to 22 carbon atoms derived. Use according to at least one of Claims 1 to 7, characterized in that the alkyl esters and the partial glycerides are derived from rapeseed oil fatty acids. Use according to at least one of claims 1 to 8, characterized in that the fuel compositions are diesel. Use according to at least one of claims 1 to 9, characterized in that the alcohol is butanol, ethanol and / or methanol. Use according to at least one of claims 1 to 10, characterized in that the fuel composition in addition to the non-aqueous phase still contains at least ethanol and / or water, preferably water and ethanol. Use according to at least one of claims 1 to 11, characterized in that the fuel composition comprises 60 to 99% by weight of diesel, 0.5 to 20% by weight (preferably 2 to 15% by weight) of the composition according to the description of Claims 1 to 8 as an additive, 0.5 to 20 wt .-% ethanol and 0 to 1% additional water - in addition to the water content in the additive or in the ethanol - contains. Use according to at least one of claims 1 to 12, characterized in that the fuel composition contains ethanol, wherein an ethanol with 96.0 vol .-%, preferably 99.0 vol .-% and preferably 99.9 vol .-% ethanol selected is. Fuel composition containing 60 to 99 wt .-% diesel, 0.5 to 20 wt .-% (preferably 2 to 15 wt .-%) of the composition according to the description of claims 1 to 8 as an additive, 0.5 to 20 wt % Ethanol and 0 to 1% additional water in addition to the water content in the additive or in the ethanol.

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