DE102022114815A1 - Process for removing deposits from internal combustion engines - Google Patents

Abstract

The present invention relates to a method for removing deposits from internal combustion engines using water emulsified in fuels.

Description

The present invention relates to a method for removing deposits from internal combustion engines using water solubilized in fuels.

It has long been known to add water to fuels in order to reduce emissions during combustion in the engine.

CN102051241 describes additives for diesel fuels containing oleic acid, ethoxylated sorbitol monostearate, methanol, ethanol, calcium naphthenate, dodecylbenzene sulfonic acid and naphthenic acid. This additive can be used to emulsify water in diesel fuel. The advantage mentioned is that this additive does not block the nozzles and has good stability.

DE19917753 describes fuel emulsions with less than 0.3% by volume of emulsifier and at least 20% by volume of demineralized water. The use of ultrapure water has the effect of reducing engine deposits.

WO 2001/055282 describes alkoxylated polyisobutenes as emulsifiers for water in fuel emulsions, especially for diesel. The emulsions have a droplet size of 0.5 to 5 µm and give small amounts of combustion chamber deposits.

The present invention relates to a fuel composition, in particular diesel fuel composition, containing 0.1 to 10% by weight of at least one emulsifier (B) and 200 ppm, preferably at least 300, particularly preferably at least 400 ppm to 5% by weight of water (A) emulsified in the fuel composition. , characterized in that the average diameter of the water-containing micelles in the fuel composition is not more than 100 nm, preferably not more than 80, particularly preferably not more than 50 nm, very particularly preferably not more than 30 nm, in particular not more than 20 nm (measured by dynamic light scattering according to).

The mean diameter is generally at least 1 nm, preferably at least 2, particularly preferably at least 3, very particularly preferably at least 4 and in particular at least 5 nm.

With this water-based fuel composition it is possible to remove deposits in engines, especially deposits on valves, in the combustion chamber and on injectors.

This water-containing fuel composition is particularly suitable for removing deposits on injectors in direct-injection engines, in particular diesel engines. In particular, so-called inner diesel injector deposits are removed.

Deposits in the injection systems of modern diesel engines cause significant performance problems. It is widely recognized that such deposits in the spray channels can lead to a reduction in the fuel flow and thus to power losses. Deposits on the injector tip, on the other hand, impair the optimal formation of fuel spray and thus cause poorer combustion and the associated higher emissions and increased fuel consumption. In contrast to these conventional, "external" deposit phenomena, "internal" deposits (collectively referred to as internal diesel injector deposits (IDID)) also prepare in certain parts of the injectors, such as on the nozzle needle, on the control piston, on the valve piston, on the valve seat the control unit and the guides for these components are increasingly experiencing performance problems.

“IDID” stands for “Injector Nozzle Deposits” or “Internal Injector Nozzle Deposits” as seen on modern diesel engines. While conventional (external) deposits are coke-like deposits in the area of the needle tips and the spray holes of the injectors, deposits have accumulated in the meantime on the inside of the injectors and lead to significant performance problems, such as blocking of the internal moving parts of the valve and associated deteriorated or lack of fuel injection control, loss of power and the like. The IDIDs occur both in the form of waxy or soapy deposits (fatty acid residues and/or C ₁₂ - or C ₁₆ -alkyl succinic acid residues can be detected analytically), especially as soaps of certain metals, and in the form of polymer-like carbon deposits. The latter, in particular, have special requirements in terms of their removal/avoidance.

It is an advantage of the present invention that the aqueous fuel blends of the present invention are effective in removing diesel injector internal deposits (IDID) from the injectors. Such injector deposits in direct-injection diesel engines can be determined, for example, using the DW10 test according to CEC F-098-08. By using the water-containing fuel mixtures according to the invention and the method according to the invention, zinc, sodium, Potassium and / or calcium-containing and polymeric deposits are reduced or removed. In general, deposits effective in the DW10 test can be reduced by at least 50%, preferably at least 60, particularly preferably at least 70, very particularly preferably at least 80 and in particular at least 90% by the method according to the invention, and the test result can be improved accordingly.

It should be noted that the water content of the fuel compositions according to the invention is above the range permitted under DIN EN 590 (maximum value 200 ppm), so that motor vehicles should not be operated with these fuel compositions on the road.

Motor vehicles with the water-containing fuel composition according to the invention should therefore only be operated outside of public road traffic, for example in workshops, roller test benches or private areas.

Accordingly, a further object of the present invention is a method for cleaning deposits from an engine, characterized in that the engine is operated for a period of at least 5 minutes to 10 hours with a fuel composition according to the invention. The preferred time period is 5 minutes to 8 hours, more preferably 10 minutes to 6 hours, most preferably at least 15 minutes to 4 hours, in particular 20 minutes to 3 hours and especially 30 minutes to 2 hours.

In the process, deposits on valves, in the combustion chamber and/or on injectors are removed, particularly in the combustion chamber and/or on the injectors and in particular on the injectors.

The water content in the fuel composition according to the invention and the particle size of the dispersed water droplets are brought about by the emulsifier (B) used.

The emulsifier is preferably at least one emulsifier selected from the group consisting of alkoxylated fatty acid amides (B1), alkoxylated alcohols or phenols (B2) and alkoxylated alkylamines (B3).

The emulsifier can be a compound or a mixture of 2 or more, usually 1 to 3 emulsifiers are sufficient, preferably 1 to 2 and particularly preferably one emulsifier.

Preferred alkoxylated fatty acid amides (B1) are those of the formula ^R1 -(C=O)-NH _u (-[-R2 ^-O ] _w -H) _v
wherein
R ¹ is an alkenyl or alkyl radical having 7 to 17 carbon atoms,
R ^{2 is} a 1,2-ethylene or 1,2-propylene radical, preferably 1,2-ethylene,
u either 0 or 1,
v either 1 or 2, and
w is a positive integer from 1 to 5
mean,
where (u + v) always equals 2.

The underlying carboxylic acids R'COOH are preferably fatty acids or mixtures of fatty acids such as can be obtained from naturally occurring fats and oils.

Preferred fatty acids are stearic acid, palmitic acid, lauric acid, oleic acid, linoleic acid and linolenic acid.

Industrially customary fatty acid mixtures are preferably tallow fatty acid, coconut oil fatty acid, trans fatty acid, coconut palm kernel oil fatty acid, soybean oil fatty acid, rapeseed oil fatty acid, peanut oil fatty acid or palm oil fatty acid, which contain oleic acid and palmitic acid as main components.

The fatty acid amides (B1) can be obtained, for example, by reacting these fatty acids or esters of the fatty acids with ammonia, monoethanolamine, diethanolamine, monopropanolamine or dipropanolamine, optionally with subsequent alkoxylation, preferably with ethylene oxide or propylene oxide or mixtures thereof, until the desired average degree of alkoxylation (in the above Formula (v x w)) is reached.

The alkoxylation is preferably omitted and the fatty acid amides (B1) are obtained by reaction with monoethanolamine, diethanolamine, monopropanolamine or dipropanolamine, particularly preferably by reaction with monoethanolamine or diethanolamine and very particularly preferably by reaction with diethanolamine.

Preferred alkoxylated alcohols or phenols (B2) are those of the formula R ³ -O-[-CH ₂ -CH ₂ -O-] _x -H
wherein
R ³ is an alkyl radical having 8 to 18 carbon atoms or a C ₈ - to C ₁₈ -alkylphenol radical, preferably octylphenyl radical or nonylphenyl remainder and x is a positive integer from 3 to 15, preferably 3 to 8
means.

The underlying alcohols R ³ —OH are, for example, fatty alcohols of the fatty acids and fatty acid mixtures listed above under (B1).

Preferred alcohols R ³ -OH are octanol, decanol, dodecanol, tetradecanol, hexadecanol and octadecanol, each preferred as linear n-alkanols.

Examples of branched alkanols are tridecanol and heptadecanol, as described for example in WO 2005/37752 or in WO 2009/124979 .

Examples of alkyl phenols are octyl phenol, nonyl phenol, decyl phenol, undecyl phenol, dodecyl phenol, tridecyl phenol, tetradecyl phenol, hexadecyl phenol, heptadecyl phenol and octadecyl phenol.

The degree of ethoxylation is from 3 to 15, preferably from 3 to 12, particularly preferably from 3 to 8.

Preferred alkoxylated alkylamines (B3) are those of the formula H-[-O- _{CH2 -CH2} -] _y ^-NR4 -[- _{CH2 -CH2} -O-] _z -H
wherein
R ⁴ is an alkenyl or alkyl radical having 12 to 18 carbon atoms and
y and z are each independently a positive integer from 2 to 10
mean.

The underlying alkylamines R ⁴ -NH ₂ are, for example, fatty amines of the fatty acids and fatty acid mixtures listed above under (B1).

Preferred alkylamines R ⁴ -NH ₂ are dodecylamine, tetradecylamine, hexadecylamine and octadecylamine, each preferred as linear n-alkylamines.

The degree of ethoxylation (y+z) is from 2 to 10, preferably from 2 to 8, particularly preferably from 3 to 8.

The content of emulsifier or emulsifier mixture (B) in the fuel mixture according to the invention is generally 0.1 to 10% by weight, based on the total amount of fuel, emulsifier and water, preferably 0.2 to 9, particularly preferably 0.3 to 8, very particularly preferably 0.4 to 7, in particular 0.5 to 6 and especially 0.6 to 5% by weight.

The water contained in the fuel mixture according to the invention should contain as few hardness factors as possible, or generally few metal salts, especially zinc, sodium, potassium and/or calcium, and should preferably have a hardness of not more than 8.4°dH. Particular preference is given to using deionized, distilled or double-distilled water, very particularly preferably deionized water.

The amount of water in the fuel mixture according to the invention is generally 200 ppm by weight to 5% by weight, based on the total amount of fuel, emulsifier and water, preferably from 300 ppm by weight to 4% by weight, particularly preferably 400 ppm by weight to 3 wt% and most preferably from 500 wppm to 2.5 wt%.

The amount of emulsifier and the amount of water are tailored to the fuel used in each case in such a way that the mean diameter (z-average) of the water-containing micelles in the fuel composition is no more than 100 nm, preferably no more than 80, particularly preferably no more than 50 nm particularly preferably not more than 30 nm, in particular not more than 20 nm (measured by dynamic light scattering according to). The measurement is preferably carried out in accordance with ISO standard 22412 and particularly preferably with a Malvern Nanosizer, wavelength of the laser: 633 nm.

The mean diameter is generally at least 1 nm, preferably at least 2, particularly preferably at least 3, very particularly preferably at least 4 and in particular at least 5 nm.

In general, the desired particle size is achieved with a weight ratio of emulsifier (B) to water (A) of 1:1 to 50:1, preferably 2:1 to 10:1, particularly preferably 3:1 to 7:1.

As a rule, the emulsifier or the emulsifier mixture (B) is worked into the fuel first, followed by the desired amount of water. However, it is also possible to premix emulsifier and water and introduce them into the fuel at the same time.

The mixing of the fuel with (B) and water usually takes place through energy input through shearing energy. This can be done, for example, in dynamic mixers, ie by mixing using a stirrer or by pumping (natural circulation or forced circulation) or pumping with static mixing elements such as static mixers or nozzles in the pump circuit, by static mixing apparatus such as static mixers, nozzles, screens or T-pieces in the inlet of the preparation tank, or by dynamic mixing apparatus such as mixing pumps or stirred tanks.

The fuel is preferably initially introduced and (B) and water are added in a constant stream or in one or more portions.

The mixing temperature is generally from 10 to 60°C, preferably from 15 to 50°C and particularly preferably from 20 to 40°C. Mixing can of course also be carried out at a higher or lower temperature, as long as the components do not decompose under the chosen conditions. However, this usually does not bring any advantages. Mixing preferably takes place at ambient temperature.

The additive according to the invention is outstandingly suitable as a fuel additive and can in principle be used in any fuel. It brings about a whole range of beneficial effects when operating internal combustion engines with fuels. The quaternized additive according to the invention is preferably used in middle distillate fuels, in particular diesel fuels.

In principle, the use according to the invention relates to any fuel, preferably diesel and Otto fuels, particularly preferably diesel fuels.

Middle distillate fuels such as diesel fuels or heating oils are preferably petroleum raffinates which usually have a boiling range of 100 to 400.degree. These are mostly distillates with a 95% point up to 360°C or even higher. However, this can 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% by weight or by a 95% point of for example 285°C and a maximum sulfur content of 0.001% by weight. In addition to the mineral middle distillate fuels or diesel fuels that can be obtained through refining, there are also those that have been produced through coal gasification or gas liquefaction [“gas to liquid” (GTL) fuels] or through biomass liquefaction [“biomass to liquid” (BTL) fuels]. are available. Mixtures of the aforementioned middle distillate fuels or diesel fuels with regenerative fuels such as biodiesel or bioethanol are also suitable.

The qualities of heating oils and diesel fuels are specified in more detail, for example, in DIN 51603 and EN 590 (cf. also Ullmann's Encyclopedia of Industrial Chemistry, 5th edition, volume A12, p. 617 et seq.).

The use according to the invention in middle distillate fuels of fossil, vegetable or animal origin, which are essentially hydrocarbon mixtures, also relates to mixtures of such middle distillates with biofuel oils (biodiesel). Such mixtures are encompassed by the term "middle distillate fuel". They are commercially available and usually contain the biofuel oils in minor amounts, typically in amounts of 1 to 30% by weight, in particular 3 to 10% by weight, based on the total amount of middle distillate of fossil, vegetable or animal origin and biofuel oil.

Biofuel oils are typically based on fatty acid esters, preferably essentially on alkyl esters, of fatty acids derived from vegetable and/or animal oils and/or fats. Alkyl esters are usually understood to mean lower alkyl esters, in particular C ₁ - to C ₄ -alkyl esters, which are obtained by transesterification of the glycerides occurring in vegetable and/or animal oils and/or fats, in particular triglycerides, using lower alcohols, for example ethanol or, above all, methanol (“ FAME"), are available. Typical lower alkyl esters based on vegetable and/or animal oils and/or fats that are used as biofuel oil or components thereof are, for example, sunflower methyl ester, palm oil methyl ester ("PME"), soybean oil methyl ester ("SME") and in particular rapeseed oil methyl ester ("RME") .

The middle distillate fuels or diesel fuels are particularly preferably those with a low sulfur content, ie with a sulfur content of less than 0.05% by weight, preferably less than 0.02% by weight, in particular less than 0.005% by weight and especially less than 0.001% by weight sulphur.

All commercially available petrol compositions can be used as petrol. The standard Eurosuper base fuel according to EN 228 should be mentioned here as a typical representative. Furthermore, gasoline compositions are also in accordance with the specification WO 00/47698 possible areas of application for the present invention.

Unless otherwise stated, the ppm and percentage data used in this document relate to weight percentages and ppm.

The mean particle size (z-average) used in this specification is measured using dynamic light scattering with Malvern® Autosizer 2C unless otherwise noted.

Measurement with Malvern Nanosizer, wavelength of the laser: 633 nm. The mean micelle sizes to be expected should be between 7 and 20 nm. ISO standard: 22412

The following examples are intended to illustrate the invention but are not intended to limit it to these examples.

examples

• Beispiel 1 50 g Dieselkraftstoff 0,8 g vollentsalztes Wasser 2,4 g Cocosfettsäure diethanolamid
• Beispiel 2 20 g Dieselkraftstoff 0,04 g vollentsalztes Wasser 0,06 g Ölsäure diethanolamid 0,02 g siebenfach ethoxyliertes Nonylphenol
• Beispiel 3 10 g Dieselkraftstoff 0,08 g vollentsalztes Wasser 0,16 g Ölsäure diethanolamid
• Beispiel 4 40 g Dieselkraftstoff 0,08 g vollentsalztes Wasser 0,17 g vierfach ethoxyliertes 2-Propylheptanol 0,36 g C8/18-alkyl-diethanolamin

With the following formulations, fully desalinated water can be clearly solubilized in diesel fuel:

• Example 1 50 g diesel fuel 0.8 g deionized water 2.4 g coconut fatty acid diethanolamide
• Example 2 20 g diesel fuel 0.04 g deionized water 0.06 g oleic acid diethanolamide 0.02 g sevenfold ethoxylated nonylphenol
• Example 3 10 g diesel fuel 0.08 g deionized water 0.16 g oleic acid diethanolamide
• Example 4 40 g diesel fuel 0.08 g deionized water 0.17 g quadruply ethoxylated 2-propylheptanol 0.36 g C8/18-alkyl-diethanolamine

application example

DW10 Test - Determination of power loss due to injector deposits in common rail diesel engines

To investigate the influence of the additives on the performance of direct injection diesel engines, the IDID engine test was used as a further test method, in which the exhaust gas temperatures of the cylinders at the cylinder outlet were determined during a cold start of the DW10 engine. A direct-injection diesel engine with a common-rail system from the manufacturer Peugeot was used in accordance with test methods CEC F-098-08. A commercially available B7 diesel fuel in accordance with EN 590 from Aral was used as the fuel. To artificially stimulate the formation of deposits, 1 ppm by weight of sodium naphthenate and 20 ppm by weight of dodecenylsuccinic acid were added to this.

1. I. Dirty-up:
   • Der Test wurde ohne Zusatz von Verbindungen gemäß dieser Erfindung durchgeführt. Der Test wurde auf 8 Stunden verkürzt, das CEC F-98 -08 Verfahren wurde ohne Zusatz von Zn, jedoch unter Zugabe von Natriumnaphthenat und Dodecenylbernsteinsäure durchgeführt. Wenn signifikante Abweichungen von Abgastemperaturen beobachtet wurden, wurde die Prüfung vor Erreichen der 8 Stunden-Marke angehalten, um Motorschäden zu vermeiden. Nach dem dirty up-Lauf, ließ man den Motor abkühlen und danach wurde erneut gestartet und im Leerlauf 5 Minuten betrieben. Während dieser 5 Minuten wurde der Motor aufgewärmt. Die Abgastemperatur von jedem Zylinder wurde aufgezeichnet. Je geringer die Unterschiede zwischen den ermittelten Abgas-Temperaturen sind, um so niedriger ist die Menge an gebildeten IDID.
2. II. Clean-up:
   • Der Test wurde auf 8 Stunden verkürzt, das CEC F-98 -08 Verfahren wurde ohne Zusatz von Zn wurde durchgeführt. Es wurden jedoch jeweils 1 Gew.-ppm Natriumnaphthenat sowie 20 Gew.-ppm Dodecenylbernsteinsäure sowie eine erfindungsgemäße Verbindung in einer Menge von 40 mg/kg zugesetzt, und die Motorenleistung bestimmt.

Similar to the CEC F-98 -08 procedure, engine power is measured during the test. The test consisted of two parts:

1. I. Dirty up:
   • The test was carried out without the addition of compounds according to this invention. The test was shortened to 8 hours, the CEC F-98 -08 procedure was carried out without the addition of Zn but with the addition of sodium naphthenate and dodecenylsuccinic acid. If significant deviations in exhaust gas temperatures were observed, the test was stopped before reaching the 8 hour mark to avoid engine damage. After the dirty up run, the engine was allowed to cool and then restarted and idled for 5 minutes. During these 5 minutes the engine was warmed up. The exhaust gas temperature from each cylinder was recorded. The lower the differences between the determined exhaust gas temperatures, the lower the amount of IDID formed.
2. II. Clean up:
   • The test was shortened to 8 hours, the CEC F-98 -08 procedure was performed without the addition of Zn. However, 1 ppm by weight of sodium naphthenate and 20 ppm by weight of dodecenylsuccinic acid and a compound according to the invention in an amount of 40 mg/kg were each added, and the engine output was determined.

After the clean up, the engine was cooled down and restarted. The exhaust gas temperature from each cylinder was recorded. The lower the differences between the determined exhaust gas temperatures, the lower the amount of IDID formed.

After the dirty-up run, a power loss from 97.5 kW to 91.4 kW (6.3%) was observed, indicating heavy deposits due to IDID.

A clear and transparent, water-based fuel with 2% water in the fuel was used for the clean-up run (10 hours) and the engine power was then determined at 94.4 kW (3.2% below the target value) with a water-free fuel.

The power was thus increased by 3.1% as a result of the cleaning run with the fuel according to the invention. From the course of the exhaust gas temperatures during the cleaning run, it can be seen that most of the deposits were removed during the first hour.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• CN102051241 [0003]
• DE 19917753 [0004]
• WO 2001/055282 [0005]
• WO 2005/37752
• WO 2009/124979 [0029]
• WO 0047698 [0053]

Claims (10)

Fuel composition, in particular diesel fuel composition, containing 0.1 to 10% by weight of at least one emulsifier (B) and 200 ppm to 5% by weight of water (A) emulsified in the fuel composition, characterized in that the mean diameter of the water-containing micelles in the fuel composition is not more than 100 nm (measured by dynamic light scattering according to). Fuel composition according to claim 1 , characterized in that the weight ratio of emulsifier (B) to water (A) is from 1:1 to 50:1, preferably from 2:1 to 10:1, particularly preferably from 3:1 to 7:1. Fuel composition according to one of the preceding claims, characterized in that the at least one emulsifier (B) at least one compound (B1) R ¹ -(C=O)-NH _u (-[-R ² -O] _w -H) _v in which R ¹ is an alkenyl or alkyl radical having 7 to 17 carbon atoms, R ² is a 1,2-ethylene or 1,2-propylene radical, preferably 1,2-ethylene, u is either 0 or 1, v is either 1 or 2, and w is a positive integer from 1 to 5, where (u + v) always equals 2. Fuel composition according to claim 3 , characterized in that the at least one emulsifier (B) contains at least one further compound (B2) in addition to the compound (B1) R ³ -O-[-CH ₂ -CH ₂ -O-] _x -H in which R ³ is an alkyl radical having 8 to 18 carbon atoms or a C ₈ - to C ₁₈ -alkylphenol radical, preferably octylphenyl radical or a nonylphenyl radical and x is a positive integer from 3 to 15, preferably 3 to 8. Fuel composition according to claim 3 or 4 , characterized in that the at least one emulsifier (B) contains at least one further compound (B3) in addition to the compound (B1) H-[-O- _{CH2 -CH2} -]y ^-NR4 -[- _{CH2 -CH2} -O-] _z -H wherein R ⁴ is alkenyl or alkyl of 12 to 18 carbon atoms and y and z are each independently a positive integer of 2 to 10. Use of fuel compositions according to any one of the preceding claims for removing deposits in internal combustion engines, especially diesel engines, more preferably direct injection diesel engines. use according to claim 6 , characterized in that it is deposits on internal injectors. A method of cleaning deposits from an engine, characterized in that the engine is fueled for a period of 5 minutes to 10 hours with a fuel composition according to any one of Claims 1 until 7 operates. procedure according to claim 8 , characterized in that deposits on fuel injectors are removed. procedure according to claim 8 or 9 , characterized in that deposits on fuel injectors are removed by at least 50% according to the DW10 test.