FI90349C - Intermediate distillate composition in which wax crystal size has been reduced - Google Patents

Abstract

Long chain alkyl derivs. of difunctional sulphonic gp.-contg. cpds. of formula (I) are new, where -Y-R2=SO3(-) (+)D-R2, -SO2NR3R2 or -SO3R2; -X-R1=-Y-R2, -CONR3R1, -CO2(-)(+)D-R1, -R4COOR'-R4COOR1 -NR3COR1, -R4OR1, -R4OCOR1, -R4R1 or -N(COR3)R1; D=NR3.3, HNR3.2, H2NR3 or H3N; R1, R2=alkyl, alkoxyalkyl or polyalkoxyalkyl contg. at least 10C atoms in the main chain; R3=hydrocabryl (same or different); R4=nothing or 1-5C alkylene. In the group (i) the C-C bond is either (a) ethylenically unsatd., when A and B are alkyl, alkenyl or substd. hydrocarbyl groups, or (b) part of a cyclic structure which may be aromatic, polynuclear aromatic or cycloaliphatic.

Description

90349

A selected distillate composition with reduced wax crystal size

This invention relates to an improved fuel oil distillate.

Mineral oils containing paraffin waxes, such as distilled fuels used as diesel oil and fuel oil, are characterized by the flowability of the green belt. when the temperature drops. This decrease in fluidity is due to the crystallization of the wax into plate-like crystals, possibly forming a porous, oil-enclosing mass, and the temperature at which the wax crystals begin to form is known as the cloud point, and the temperature at which the wax prevents the oil from pouring is known.

It has long been known that various additives act as freezing point depressants when mixed with waxy mineral oils. These compounds change the size and shape of the wax crystals and reduce the cohesive forces between the crystals and the wax and oil by allowing the oil to remain liquid at lower temperatures and to remain pourable and capable of shoveling coarse filters.

Various stagnation points have been described in the literature, and many of them are in commercial use. For example, U.S. Patent 3,048,479 teaches the use of copolymers of ethylene and C 1 -C 3 vinyl esters, e.g., vinyl acetate, as a pour point depressant in fuels, particularly heating, diesel, and jet fuel fuels. Polymeric freezing point depressants based on ethylene and alpha-olefins, e.g. polypropylene, are also known. us - U.S. Pat. No. 3,252,771 relates to the use of C16-C18 polymers of alpha-olefins in combination with aluminum trichloride / alkyl halides in connection with distilled "wide boiling point" "easy to handle" fuels available in the United States in the early 1960's.

2,90349 In the late 1960s and early 1970s, great emphasis was placed on improving the filterability between the cloud point and the freezing point of oils, which was determined by the rather rigorous "Cold Filter Plugging Point" (CFPP) test (CFPP), CFPP and several patents relating to the improvement of fuel properties in this experiment have been published since then. U.S. Patent 3,961,916 teaches the use of a copolymer blend to control the size of wax crystals. GB Patent 1,263,152 proposes that the size of wax crystals be adjusted by using a copolymer with a smaller number of side branches in the chain.

GB Patent 1,469,016, for example, also suggests that copolymers of di-n-alkyl fumarates and vinyl acetate, previously used as freezing point depressants for lubricating oils, be used as separate additives for the use of ethylene / vinyl acetate copolymers. low temperature conditions.

It has also been proposed to use additives based on olefin / maleic anhydride copolymers. For example, U.S. Pat. No. 2,542,542 uses copolymers of olefins such as octadecene with maleic anhydride esterified with an alcohol such as lauryl alcohol as depressants, and GB as separate additives. Consistent with this, olefin / maleic anhydride copolymers that have reacted with an amine are used as freezing point depressants in JA Patent No. 5,654,037.

JA Patent 5,654,038 uses derivatives of olefin / maleic anhydride copolymers in combination with conventional coolant flow improvers such as ethylene-vinyl-3,90349 acetate copolymers. JA Patent No. 5,540,640 discloses the use of (non-esterified) olefin / maleic anhydride copolymers and states that the olefins used should contain more than 20 carbon atoms to achieve a CFPP effect. Mixtures of esterified olefin / maleic anhydride copolymers and low molecular weight polyethylene as defined in GB Patent 2,192,012, when used alone, are ineffective esterified copolymers.

Improvement in CFPP Efficiency The addition of the additives of these patents has been accomplished by altering the size and shape of the wax crystals and causing them to form mostly needle-like crystals generally having a particle size of 10,000 nanometers or greater, typically 30,000 to 100,000 nanometers. When operating diesel engines at low temperatures, these crystals do not pass through the engine's paper fuel filter, but form a cake that passes through the filter, which passes through the fuel, the wax crystals dissolve more slowly as the engine and fuel dissolve. However, the formation of wax can clog the filters, leading to diesel engine starting difficulties and cold weather problems at the beginning of the run, as well as interruptions in the operation of the diesel heating systems.

It has now surprisingly been found that waxy fuels with a sufficiently small wax crystal size at low permeation temperatures can be obtained by means of paper main filters, which are typically used as additives in diesel engines.

Therefore, the present invention provides fuel oils boiling in the temperature range of 120 to 500 ° C, having a wax content of at least 0.3% by weight at a temperature of 10 ° below the onset temperature of the wax and having an average particle size of the wax crystals. less than 4000 nunomet riå.

4,90349

The Wax Appearance Temperature (WAT) in the fuel is measured with a differential scanning calorimeter (DSC). In this test, a small fuel sample (25 microliters) is cooled to 2 ° C / minute together with a control sample having the same lamp charge but not precipitating as a wax in the temperature range in question (such as kerosene). When crystallization begins, an exothermic reaction is observed in the sample. For example, the WAT of the fuel can be measured by extrapolating the Metier ΤΑ 2000B with a differential scanning calorimeter11a.

The wax content of the fuel is derived from the DSC curve by integrating the area bounded by the baseline and the exothermic peak into a defined temperature space. The calibration has been performed with a known amount of crystallizing wax on the front cover.

The average particle size of the wax crystals is measured by analyzing the scanning image of the fuel sample from an electron microscope over a range of 4000-8000x magnification and measuring the maximum dimension from a predetermined screen to at least 40 points out of 88. It has now been found that by making the average particle size smaller than 4000 nanometers, the wax begins to pass through typical paper filters used in diesel engines, although a size of 3000 nanometers is now preferred, preferably less than 2000, still more preferably less than 1500 nanometers, and most preferably less than 1000 nanometers. the real benefits of passing through a paper filter. The actual size to be achieved depends on the original nature of the fuel and the amount and nature of the additives used, but it has now been found that such and smaller sizes are achievable.

The ability to produce such small wax crystals in the fuel leads to significant benefits in the usability of the diesel engine.

T.im.'i can be demonstrated by pumping the blended fuel through a diesel filter paper used for V.W. In Golf or Cummins diesel engines at 8 to 15 ml / s and 1,0 to 2,4 liters per minute per square meter of filter surface at a temperature of at least 5 ° C below the wax onset temperature of the fuel, having a solid wax content of at least 0.5% by weight. both the wax and the fuel are considered to have passed the filter successfully if one or more of the following criteria are met.

(i) After 18-20 liters of fuel have been scrubbed by the filter, the pressure drop across the entire surface of the filter shall not exceed 50 kiloPascall (kPa), preferably 25 kPa, even more preferably 10 kPa and most preferably 5 kPa.

(ii) At least 60%, preferably at least 80% and even more preferably 90% of the wax in the parent fuel, as determined by the DSC test described previously, is present in the fuel leaving the filter.

(iii) When pumping 18-20 liters of fuel, the filter blade always maintains a flow rate greater than 60% of the original flow rate, and preferably 80% of the original flow rate.

The amount of shaking crystals in the motor filter and the utility of small crystals in usability depend greatly. the length of the crystals, although the shape of the crystals is also essential.

It was now found that cube-shaped crystals have slightly better tendencies for blade filters than are characteristic of flat crystals, and have a lesser effect on increasing fuel flow resistance when they do not blade the filter. However, the primary crystal form is flat, which in principle allows a larger amount of wax to precipitate as the temperature decreases, and therefore a larger amount of wax precipitates before the critical crystal length is reached than would be the case with cubic crystals of the same length.

The fuels of this invention have striking advantages over formerly distilled fuels whose cold flow properties have been improved with conventional additives. These fuels also have improved cold start properties at 6,90349 low temperature conditions that do not depend on hot fuel recirculation to remove unwanted wax deposits. Furthermore, the wax crystals tend to remain in suspension rather than settling to the bottom of the container and forming wax layers, as is the case when treating fuels with conventional additives to aid in their distribution.

In addition, these fuels generally have better performance in the cold climate body dynamometer test compared to fuels containing conventional additives. In many cases, these fuels also have improved CFPP properties.

Normal quality distilled fuels boiling in the range of 120-500 ° C vary widely in their boiling properties, n-alkane distribution and wax content. Northern European fuels generally have lower final boiling points and cloud points than their counterparts in Southern Europe. The wax content is usually higher than 1.5% (10 ° C below WAT). Similarly, fuels around the world vary from country to country according to similar climatic conditions, but the wax content also depends on the source of the crude oil. Fuels shipped from the Middle East are likely to have lower wax content than waxy Chinese or Australian crude oils.

The size to which very small crystals can be obtained depends on the nature of the fuel itself, and for some fuels it may be impossible to obtain the most extremely small crystals of the present invention.

However, if such a problem occurs, the properties of the fuel can be changed by making it possible to obtain such small crystals, for example by changing the conditions and mixing of the refinery, and thus making it possible to use suitable additives.

The general formula of the additives we prefer is A X - R1 ^ C 1

C

B ^ - R2 7 90349 where -Y-R2 is SO3 ("] (+} NR2R2, -SO3 (') (+} HNR3R2, -so3 (_) (+) h2nr3r2, -so3 (-) U) h3nr2, -SO2NR3R2 or -SO3R2; -X-R1 is -Y-R2 or -CONR3R1, -co2 <-) (+) nr3r1, -co2 (_) (+) hnr | r1, -CO2 (_) (+) H2NR3R1, -CO2 (-) (+) h3nr1, -R4-COOR1 (-nr3cor1, 4 1 4 1 4 1 R4OR, -R OCOR1, -R * R, -N (COR3) R1 or Z (_) ^ NR R1 and -Z1-) are SO3 (*) or -CO2 (_), R1 and R2 are alkyl, alkoxyalkyl or polyalkoxyalkyl having at least 10 carbon atoms in the chain, R3 is hydrocarbyl, and each R3 may be the same or

different, and R is zero or C 1 -C 4 alkylem, and in formula A

C

c the carbon-carbon bond (CC) is either a) ethylenically unsaturated when A and B may be alkyl, alkenyl or substituted hydrocarbyl groups, or b) part of a cyclic structure which may be aromatic, polynuclear aromatic, or cyclo-1 aliphatic, is it is preferred that XR and YR between them contain at least three alkyl, alkoxyalkyl or polyalkoxyalkyl groups.

The ring atoms of such a cyclic compound are primarily carbon atoms, but may nevertheless contain an N, S or O ring atom to give the heterocyclic compound.

Examples of aromatic-based compounds from which additives can be prepared include 8 90349 0 0 in which the aromatic group may be substituted.

Alternatively, they can be obtained from polycyclic compounds, i. those with two or more ring structures that can take different shapes. They may be a) sealed Bent fungal structures, b) sealed ring structures in which none or all of the rings are benzene, c) frying-associated rings, d) non-aromatic or partially saturated ring systems, or f) three-dimensional structures.

Concentrated benzene structures from which compounds can be derived include, for example, naphthalene, anthracine, phenatrin, and pyridine.

Condensed structures in which none or not all of the rings are benzene include, for example, azulene, indene, hydroindenifluorene, diphenylene. Compounds in which the rings are attached to the roast include, for example, diphenyl. Suitable heterocyclic compounds from which they may be derived include quinoline, pyridine, indole, 2: 3 dihydroindole, benzofuran, coumarin, isocoumarin, benzothiophene, carbazole and thiodiphenylamine. Suitable non-aromatic or partially saturated ring structures include decalin (decahydronaphthalene), oU-pinene, cardine, borlylene. Suitable 3-dimensional compounds include, for example, norborene, bicycloheptane (norborane), bicyclooctane and bicyclooctene.

Both substituents X and Y are attached to related ring atoms in a ring having only one ring, or to associated 9,90349 ring atoms in one of those rings in which the compound is polycyclic. In the latter case, this means that if naphthalene is used, these substituents cannot be attached at the 1,8 or 4,5 positions, but can be attached at the 1,2-, 2,3-, 3,4-, 5,6-, 6, To 7- or 7.8 positions.

These compounds are reacted to form esters, amines, amides, half esters / half amides, half esters or salts which are used as additives. Preferred additives are salts of a secondary amine having a hydrogen or carbon-containing group or groups containing at least 10, preferably at least 12 carbon atoms. Such amines or salts can be prepared by reacting the acid or anhydride described above with an amine, or by reacting a secondary amine derivative with carboxylic acids or anhydrides. In the preparation of amides from acids, dewatering and heating are generally essential.

Alternatively, the carboxylic acid may be reacted with an alcohol containing at least 10 carbon atoms or a mixture of alcohol and amine.

The groups containing the hydrogen and carbon atoms of the substituents are preferably hydroxyl groups, although halogenated hydrocarbyl groups which preferably contain only a small number of halogen atoms (e.g. chlorine atoms), for example less than 20% by weight, could also be used. Hydrocarbyl groups are primarily aliphatic, e.g. alkylenes.

They are primarily straight-chain. Unsaturated hydrocarbyl groups, e.g. alkenyls, may also be used, but are not preferred.

Alkyl groups preferably have at least 10 carbon atoms, preferably 12 to 22 carbon atoms, for example 14 to 20 carbon atoms, and are primarily straight-chain or branched 1 or 2. Two positions. If branching occurs in more than 20% of the alkyl chains, these branches must be methyl. Other groups containing hydrogen and carbon may be shorter, e.g. containing less than 6 carbon atoms, or may have at least 10 carbon atoms if desired. Suitable alkyl groups include methyl, ethyl, propyl, hexyl, decyl, dodecyl, tetradecyl, eicosyl and docosyl (behenyl). Preferred alkyl groups include, but are not limited to, hexylene, octylene, dodesylene, and hexadylene.

In the primary structure in which the intermediate has reacted with a secondary amine, one of the substituents is primarily an amine, and the other is an amine or a diammonium salt of a secondary amine. Particularly preferred additives are amides and amine salts of secondary amines.

In order to obtain the fuels of this invention, these additives are generally used in combination with other additives, and examples of other additives include so-called "comb" polymers having the general formula:

D H "J H

II II

- c - c - c - c -

Il i

_E G _ m [_K LJ n where D = R, CO.OR, OCO.R, R'CO.OR or OR E = H or CH 2 or D or R '

G = H, or D

m = 1.0 (homopolymer) to 0.4 (molar ratio) J = H, R 'aryl or heterocyclic group, R'CO.OR K = H, CO.OR', OCO.R ', OR', CO2H L = H, R ', CO.OR', OCO.R ', aryl, CO2H n = 0.0-0.6 (molar ratio) R> C1Q R' ^ C1

If necessary, another monomer can be terpolymerized.

Since these other additives are copolymers of alpha-oleflines and maleic anhydride, they are most easily prepared by polymerizing monomers without solvents, or in a solution of a hydrocarbon solvent such as heptane, benzene, cyclohexane or at 50 ° C in the general temperature. C and usually accelerated with a peroxide or azotypic catalyst such as benzoyl peroxide or azo-diisobutyronitrile under the protection of an inert gas such as nitrogen or carbon dioxide to exclude oxygen. It is recommended but not. it is essential that equimolar amounts of olefin and maleic anhydride be used, although molar ratios in the range of 2: 1 and 1: 2 are suitable. Examples of olefins that can be copolymerized with maleic anhydride are 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octodecene.

The copolymer of olefin and maleic anhydride may be esterified by any suitable technique, and although it is preferred, it is not essential that the maleic anhydride be at least 50% esterified. Examples of alcohols that can be used include n-decan-1-ol, n-tetradecan-1-ol, n-hexadecan-1-ol, n-octadecan-1-ol. Alcohols may also contain one methyl branch per chain, for example 1-methyl, pentadecan-1-ol, 2-methyl, tridecan-1-ol The alcohol may be a mixture of ordinary and simple methyl branched alcohols. Each alcohol can be used to esterify copolymers of maleic anhydride and any olefin. It is preferable to use pure alcohols rather than commercially available alcohol mixtures, but when mixtures are used, R 'refers to the average number of carbon atoms in the alkyl group, if alcohols having a branch in the 1 or 2 position are used, refers to the straight chain backbone of the alcohol. When using mixtures, it is important that no more than 15% of the R 1 groups have the value R 1 + 2. The choice of alcohol naturally depends on the choice of olefin copolymerizable with maleic anhydride such that R + R * is in the range 18-38. The preferred value of R + R 2 "depends on the boiling properties of the fuel in which the additive is used.

The comb polymers may also be fumarate polymers and copolymers and, as described in European Patent Applications 12,90349, 0153176, 0153177, 85301047 and 85301048.

Examples of other additives which may be used in combination with cyclic compounds are polyoxyalkylene esters, ethers, ester / ethers and mixtures thereof, in particular those containing at least one, preferably at least two C10-C30 linear saturated alkyl groups and a polyoxyalkylene glycol group having a polyoxyalkylene glycol group , preferably 200-5000, and the alkyl group of said polyoxyalkylene glycol contains 1 to 4 carbon atoms. These substances form the subject of European Patent 0 061 895 B. Other such additives are described in U.S. Patent 4,491,455.

Preferred esters, ethers or ester (s) useful in this invention may be structurally represented by the formula: R-O (A) -O-R "wherein R and R" are the same or different, and may be i) n-alkyl

II

ii) n-alkyl-C 0

II

iii) n-alkyl-O-C-O 0

Η II

iv) the n-alkyl-O-C (CH2) n-C-alkyl group is linear and saturated and contains 10 to 30 carbon atoms, and A represents a polyoxyalkylene block of glycol having 1 to 4 carbon atoms in the alkylene group, such as a polyoxymethylene, polyoxyethylene or polyoxytrimethylene moiety , which is substantially linear; some degree of branching to the lower α-side chains is tolerable, but it is recommended that the glycol be substantially linear, A may also contain nitrogen.

13 90349

Suitable glycols are generally substantially linear polyethylene glycols (PEG) and polypropylene glycols (PPG) having a molecular weight of about 100-5000, preferably about 200-2000. Preferred are esters and fatty acids containing from 10 to 30 carbon atoms useful for reacting with glycols to form ester additives, and preferably C 1 -C 6 is used. fatty acids, especially behenic acids. The esters may also be prepared by esterification of polyethoxylated fatty acids or polyethoxylated alcohols.

Polyoxyalkylene diesters, diethers, ether / esters and mixtures thereof are suitable for use as additives with diesters in narrow boiling point distillates, while small amounts of monoethers and monoesters may be present and are often formed in the manufacturing process. For the preparation of additives, it is important that a large amount of dialkyl compound is present. Mixtures of stearic or benzene diesters or polyethylene / polypropylene glycol are particularly preferred. The additives used may also contain an unsaturated copolymer of ethylene as flow improvers. Unsaturated monomers which can be copolymerized with ethylene include mono- and diesters of the general formula:

R6 H

C = C

R 5 R 7 is hydrogen or methyl, R 8 is -OOCR 8, wherein R 6 is hydrogen or C 1 -C 6, most usually C 1 -C 6, 3a preferably C 1 -C 6, straight or branched chain alkyl; or R 1 is -OOCRO, wherein R 8 is as described above but is not hydrogen, and R 8 is hydrogen or -COOR 8 as defined above. When R ^ and R? are hydrogen and R 9 is -OOCR 8, the monomers include C 1 -C 4 vinyl alcohol esters C 1 -C 10, monocarboxylic acid, and primarily C 2 -C 2 M 'even more usually C 1 -C 18 monocarboxylic acid, and preferably -Cg monocarboxylic acid. Examples of vinyl esters that can be copolymerized with ethylene include vinyl acetate, vinyl propionate and vinyl butyrate, of which vinyl acetate is preferred.

14 90349

When used, we recommend that the copolymers contain 5-40% by weight of vinyl ester, preferably 10-35% by weight of vinyl ester. They may also be blends of the two copolymers described in U.S. Patent 3,961,916. It is recommended that these copolymers have a number average molecular weight of 1000-10,000, preferably 1000-5000, as measured by vapor fractional osmometry.

The additives used may also contain other polar compounds, either ionic or non-ionic, which have the ability in fuels to act as inhibitors of the growth of wax crystals. Polar nitrogen-containing compounds have been found to be particularly effective when used in combination with glycol esters, ethers or ester / ethers. These polar compounds are generally amine salts and / or amides formed from at least one molar portion of a hydroxyl-substituted amine with a hydrocarbyl acid having 1 to 4 carboxyl groups or anhydrides thereof; esters / amides containing a total of 30-300, preferably 50-150 carbon atoms can also be used. These nitrogen compounds are described in U.S. Patent 4,211,534. Suitable amines are usually long-chain (-: ^ 2-C40 Pr'im ^ r; '- s <secondary, tertiary and quaternary amines or mixtures thereof, but shorter chain amines may also be used). amines, provided that the resulting nitrogen compound is oil soluble, and usually contains a total of about 30 to 300 carbon atoms, The nitrogen compound preferably contains at least one straight chain alkyl block.

Suitable amines include primary, secondary, tertiary and quaternary amines, but primary ones are secondary. Tertiary and quaternary amines can only form amine salts.

Examples of suitable amines include tetradecylamine, coconut amine, hydrogenated thallamine and the like. Examples of 90349 secondary amines include dioctadecylamine, methyl-behenylamine and the like. Amine mixtures are also suitable, and many amines derived from natural raw materials are mixtures.

The primary amine is a secondary hydrogenated thallium amine of the formula HNR.R wherein R and R are alkyl groups derived from hydrogenated thallamine of approximately 4% C ^, 31% 59% C ^ g.

Examples of carboxylic acids (and their anhydrides) suitable for the preparation of these nitrogen compounds include cyclohexane, 1,2-dicarboxylic acid, cyclohexene-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, naphthalenedicarboxylic acid and the like. These acids generally have about 5 to 13 carbon atoms in the cyclic moiety. Preferred acids useful in this invention are benzenedicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid. Particularly preferred is phthalic acid or its anhydride. Particularly preferred compounds are amide amine salts formed by reacting 1 molar part of phthalic anhydride with 2 molar parts of dihydrated thallamine. Another preferred compound is a diamine formed by dehydration of this amide-amine salt.

Hydrocarbon polymers may be used in the preparation of the fuels of this invention as part of the added combination. They are described by the following general formula: “th! ”Ϋ H” I I I i --c - c ---- c - c--

I I I I

_t tJ vhuw where T = H or R 'U = Η, T or aryl v = 1.0-0.0 (molar ratio) w - 0.0-1.0 (molar ratio) R ^ is normal, more than lo carbon atoms containing an alkyl group.

16 90349

These polymers can be prepared directly from ethylenically unsaturated monomers, or indirectly by hydrogenation of polymers made from other monomers such as isoprene and butadiene.

A particularly preferred hydrocarbon polymer is a copolymer of ethylene and propylene, preferably having an ethylene content of between 50 and 60% by weight.

The amount of additive required in the preparation of the distilled fuels of this invention varies depending on the combustion oils, but is generally 0.001 to 0.5% by weight, for example 0.01 to 0.1% by weight (active substance) based on the weight of the fuel oil. The additive is dissolved in the most suitable solvent to form a 20-90, e.g. 30-80% by weight concentrate in the solvent. Suitable solvents include kerosene, aromatic fuel oils, mineral lubricating oils, etc.

The present invention is illustrated by the following examples in which the size of wax crystals in fuels was measured by placing fuel samples in 60 ml bottles in refrigerated cabinets for 1 hour above a cloud point of about 8 ° C until the fuel temperature stabilized. The cabinet was then cooled to 1 ° C per hour in a test lamp room, which was then stored.

A front filter holder consisting of a 10 mm diameter sintered ring surrounded by a 1 mm wide annular metal ring supporting a 200 nanometer silver membrane filter held in place by two vertical rods is placed on top of the vacuum device. A vacuum of at least 80 kPa is developed, and the cooled fuel is dropped onto the membrane with a clean drip pipette until a small dome-shaped liquid slice just covers the membrane. To amplify the dome, fuel is added slowly; after about 10-20 drops of fuel have been dripped, the dome is allowed to dry, leaving a thin non-polished 17 90349 wet wax cake of Mata fuel on the film. The thick layer of wax si rinses thoroughly, and the thin layer can be rinsed off. The optimal layer thickness depends on the shape of the crystals, with "leaf-like" crystals requiring thinner layers than "grain-like" crystals. It is important that the final cake looks matte. An "audible cake" indicates too much fuel and the "lubricity" of the crystals, and such a cake should be discarded.

The cake is then washed with a few drops of methyl ethyl ketone, which is allowed to dry completely. The procedure is repeated a few times. When the wash is complete, the methyl ethyl ketone disappears very quickly, leaving a brilliant "Matan-white" surface that turns gray upon the addition of another drop of methyl ethyl ketone.

The washed sample is then placed in a cold desiccator and kept there until ready for coating under an electron microscope. To protect the wax, it may be necessary to keep the sample cooled, in which case it should be stored in a cooling box that can be transported (in a suitable transport box) to the electron microscope to prevent the formation of fractions on the surface of the sample.

During the coating, the sample must be kept as cold as possible to minimize damage to the crystals. the elastic contact with the rack is best effected by a fixing screw which presses the ring ring onto the edge of a recess in the rack which is shaped to allow the surface of the sample to be towards the focal plane of the device. Electrically conductive paint can also be used.

After baling, micrographs are placed in a scanning electron microscope in a conventional manner. To determine the average crystal size, the photomicrographs are analyzed by affixing a patch-shaped, 88-dot film on a suitable micrograph on top of a grid of regular, checkered, 8 rows and is 90 3 49 11 columns. The magnification should be such that only a few of the largest crystals come into contact with more than one point, and a magnification of 4000-8000 has proven to be appropriate. The crystal must be measured at each point of the lattice where the point touches the dimension of the crystal, the shape of which can be clearly defined.

The "decomposition" of the crystals is also measured in the same way as the Gaussian standard deviation, to which Bessel's correction has been applied.

The wax content before and after the filter is measured using a differential scanning calorimetry DSC (such as e.g.

DuPont 9000 Series) capable of forming a curve of approximately 100 cm in area from 1% waxy fuel with a variation in the noise-induced output of the device with a standard deviation of less than 2% of the average output signal.

The DSC is calibrated by using an additive that generates large crystals that can be reliably removed by a filter by circulating this calibration fuel in the ring in a test lamp mode and measuring the wax-released fuel WAT by DSC. Samples of the fuel in the tank and the fuel after the filter are then analyzed by DSC and the area of each fuel above the baseline of the WAT determined with the calibration drip fuel is determined.

Ratio The area of the DSC to the sample after the filter The area of the DSC to the sample in the silo is the percentage of wax remaining after the filter.

The cloud point of distilled fuels was determined by a standard cloud point test (IP-219 or ASTM-D 2500), other measurements of the onset of crystallization are the wax onset point (WAP) test (ASTM-D. 3117-72) and the wax onset lamp (WAT) state, and are performed on a differential scanning calorimeter using a Mettler® 2000B differential scanning calorimetry.

19 90349

The ability of the fuel to pass through the main filter of the diesel engine was determined by equipment consisting of a typical main filter of a diesel engine mounted on a fuel line in a standard housing; suitable are the Bosch type used in the diesel engine of a 1980 VW Golf car, and the Cummins FF105, such as that used in the Cummins NTC engine series. Sailio, which was able to store half of the fuel in a normal fuel cylinder and the resulting intake system, was routed through the spent fuel injection pump in VW Golf to suck fuel through the filter at constant flow as in the engine. The equipment houses gauges to measure the ground pressure drop across the fuel, the flow-rate in the injection pump, and the temperature chambers. Silos are placed in the equipment to receive the pumped fuel, both the "injected" fuel and the excess fuel.

The fuel storage tank is loaded with 19 liters of fuel and the tank is tested for leaks. When everything is satisfactory, the air temperature is stabilized at 8 ° C above the cloud point of the fuel. Thereafter, the unit is cooled to 3 ° C / hour in a ground test lamp space and held there for at least 3 hours to stabilize the fuel lamp space. The sieve is shaken vigorously to disperse the wax therein; a sample is taken from the silo and 1 liter of fuel is optionally removed from the sampling point after the silo in the core line and returned to the silo. It is then started with a pump set to a speed of 110 km / h.

.. In the case of the VW Golf, this speed is 1,900 rpm, which corresponds to an engine speed of 3,800 rpm. The pressure drop in the filter and the flow rate of fuel from the injection pump are monitored until fuel is typically consumed in 30-35 minutes.

If the fuel supply to the nozzles can be maintained at 2 ml per second (the amount of overflow fuel is about 6.5-7 ml / s), the result is "RELEASED". A decrease in the flow rate of the fuel pumped to the injectors indicates the "LIMIT CASE" result, and zero flow from the "El LAPAISSYT" result.

20 90 349

In general, the "LÅPÅISSYT" result is associated with an increased pressure drop in the filter, which can rise as high as 60 kPa. Generally, a filter is required from the blades of significant amounts of wax to achieve such a result. The "SHOVEL WELL" result is characterized by an experiment in which the pressure drop in the filter does not rise above 10 kPa, and is the first indication that most of the wax has shaken the filter, with an excellent result in a pressure drop below 5 kPa.

In addition, samples of "overflow" fuel and "fuel fed to the nozzles" are ideally taken every four minutes. These samples are compared together with the samples from the post-experimental silo to determine the DSC-fed filter paddle wax. Samples of the fuel are also taken before the test, and samples from the electron microscope are prepared from these and post-test samples for a true comparison of the size and species of the wax crystals.

The additives used were:

The 1, N-dialkylammonium salt of 2-dialkylamido-benzenesulfonate, wherein the alkyl groups are n-N-dialkylammonium salt, was prepared by reacting 1 mole of cyclic anhydride of orthosulfobenzoic acid with 2 moles of di (hydrogenated) thallamine at 50% w / v. The reaction mixture was stirred between 100 ° C and reflux temperature. The solvent and chemicals should be kept as dry as possible to prevent hydrolysis in the anhydride.

The product was analyzed by 500 MHz Nuclear Magnetic Resonance Spectroscopy, which confirmed the structure to be

O

II

- »<CV <CH2> 14/16-CH3> 2 ror SO3t -> <+) N„ 2 (CH2- (CH2) 14/16-CH3) 2 2i 90 3 49

Additive 2

A copolymer of ethyl and vinyl acetate having a molecular weight of 1700 by weight of 1700 and having 8 methyl per 100 methyl groups in the side chain branches at 500 MHz as measured by NMR.

Additive 3

A styrene-dialkyl maleate copolymer prepared by esterifying i: 1 molar copolymer of styrene-maleic anhydride with 2 moles of a 1: 1 molar mixture of CH 2 OH and 1z , in which p-toluenesulfonic acid (1/10 mole) in a toluene solvent was used as a catalyst, which gave a number average molecular weight of 50,000 and contained 3% by weight of unreacted alcohol.

Additive 4 The dialkylammonium salts of 2-N, N-dialkylamidobenzoate were formed by mixing one molar portion of phthalic anhydride with two molar portions of dihydrated thallamine at 60 ° C.

The results were as follows:

Example 1

Fuel properties

Melting point -14 ° C

Wax on -18.6 ° C

Initial boiling point 178 ° C

20% 230 ° C

90% 318 ° C

Final boiling point 355 ° C

Wax content at -25 ° C 1.1% by weight

Each of the additives 1, 2 and 3,250 ppm was charged to the fuel and the test lamp temperature was -25 ° C. Wax crystals were found to be 1200 nanometers long, and more than 90% of the wax would shovel the Cummins FF 105 filter.

During the experiment, the permeability of the wax was further detected by observing a decrease in pressure in the filter, which increased by only 2.2 kPa.

Example 2

The experiment of Example 1 was repeated, and the size of the wax crystals was found to be 1300 nanometers, and the maximum final pressure drop was 3.4 kPa.

Example 3

Fuel properties

Melting point 0 ° C

Wax onset temperature -2.5 ° C

Initial boiling point 182 ° C

20% 220 ° C

90% 354 ° C

Final boiling point 385 ° C

Wax content in the test lamp compartment 1.6% by weight

Each additive 1, 2 and 3 was used at 250 ppm and the size of the wax crystals was found to be 1500 nanometers, and about 75% by weight shook the Bosch filter 145434106 at a test lamp temperature of -8.5 ° C. The maximum pressure drop in the filter was 6.5 kPa.

Example 4

The experiment of Example 3 was repeated and the wax crystals were found to be 2000 nanometers in length, of which about 50% shoveled the filter, giving a maximum pressure drop of 35.3 kPa.

Example 5

The fuel used in Example 3 was treated with 400 ppm of a mixture of Additive 1 and 100 ppm of Additive 2 and tested at -B ° C as in Example 3, where the wax content was 1.4% by weight at room temperature. The wax crystals were found to be 2500 nanometers in length, and 50% of the wax was shoveled at a filter pressure drop of 67.1 kPa at most.

23 90349

Comparative Example 6

The fuel used in Example 3 was treated with 500 ppm of a mixture of 4 parts of additive 4 and 1 part of additive 2 and tested at -8 ° C. The size of the wax crystals was found to be 6300 nanometers, and 13% by weight of the wax shook the filter.

This experiment is one of the best among the examples that did not shake the filter.

The scanning images of the electron microscope of the wax crystals formed by the fuels of Examples 1-6 are shown in the corresponding Figures 1-6.

Therefore, Examples 1-6 show that if the crystals can reliably blade the filter, better wax properties can be created for higher wax concentrations in the fuel than has ever been possible, and also lower in temperature conditions below the wax detection point than has been possible. This is possible regardless of the structure of the fuel system, such as the ability to circulate fuel from the engine to heat the feed fuel sucked from the fuel tank, regardless of the ratio of fuel fuel volume to return fuel land

Examples 1-3 show that crystal lengths of less than about 1800 nanometers with tested filters result in dramatically better fuel properties.

Example. 7

In this example, additive 1 was added to a distilled fuel having the following properties: 90349 24

IBP (initial boiling point) 180 ° C

20% 223 ° C

90% 3 3 6 ° C

pBP (final boiling point) 365 ° C

wax onset temperature (WAT) -5.5 ° C

Turbidity point -3.5 ° C

The following additives were also added to the distilled fuel for comparison purposes:

Bisan A: Ethylene / vinyl acetate copolymers, one of which was Additive 2 (1 part by weight) and the other (3 parts by weight) had a vinyl acetate content of 36%, a number average molecular weight (Mn) of 2000, and a degree of side chain branching of about 2-3 methyl per 100 methyl groups measured by NMR at 500 MHz.

Bisan B: A mixture of additives 2 and 4 in a molar ratio of 4: 1.

Bisan C: Dibehenate of polyethylene glycol with an average molecular weight of 600.

Additive D: Ethylene / propylene copolymer with an ethylene content of 56% by weight and a number average molecular weight of about 60,000.

Bisants were added below the amounts indicated in the table, and the experiments were performed according to the PCT, the details of which are as follows:

Programmed cooling test (PCT)

This is a slow cooling test designed to match the pumping of stolen fuel oil. The cold flow properties of fuel oil containing additives are determined by PCT as follows. 300 ml of fuel has been uniformly cooled to 1 ° C / hour in the test temperature, and then the temperature has been kept constant. After 2 hours at the test temperature, about 20 ml of the surface layer is removed by suction to prevent the effect of unusually large wax crystals which tend to form on the oil / air interface during cooling. The wax precipitated in the flask is dispersed with gentle agitation and then poured into a Cfppt (1) filter assembly. Open the tap which creates a vacuum in the 500 mm mercury column and close the tap after 200 ml of fuel has been poured into a collecting vessel fitted with a filter scale: Mark RELEASED if these 200 ml have been collected in ten seconds at a specified mesh RELEASED if the flow rate is too low, which indicates that the filter is clogged.

Indicate the mesh number of the sieve passed in the test.

(1) The Cold Filter Plugging Point Test (CFPPT) cold filter clogging point test is described in detail in the Journal of the Institute of Petroleum, Vol. 510, June 1966, pages 173-185.

Table

Additive (molar ratio) Density PCT mesh number shaken at -11 ° C 150 ppm 250 ppm (active _ _ _substance) A 100 200 4 60 120 1 200 350 4/2 (4/1) 100 350 1/2 ( 4/1) 350 350 4 / C (9/1) 150 250 1 / C (9/1) 250 350 4 / D (9/1) 150 350 1 / D (9/1) 350 350

It can be seen that when only one additive has been added, the best results have been obtained with additive 1, and when Knyt Ptty 1 i horn nepare and, the best results have been obtained when the second pair is additive 1.

26 90 349

Example 8

Tri .s s ri in the example The characteristics of the fuel used are as follows:

IBP (initial boiling point) 190 ° C

20% 246 ° C

90% 346 ° C

FBP (final boiling point) 374 ° C

Wax appearance temperature -1.5 ° C

Turbidity point + 2.0 ° C

It was treated with 1000 ml of the active ingredient of the following additives.

(E) A mixture of Additive 2 (1 part by weight) and Additive 4 (9 parts by weight).

(F) Ethylene-vinyl acetate copolymer additive sold under the tradename ECA 5920 by Exxon Chemicals.

(G) With a mixture of 1 part of additive 1 1 part of additive 3 1 part of additive D 1 part of additive K.

(H) A commercial ethylene-vinyl acetate copolymer additive marketed by Amoco under the name 2042E.

(I) BASF's commercial ethyl vinyl propionate copolymer additive Keroflux 5486.

(J) No additive.

(K) With a reaction product obtained from 4 moles of dihydrated thallium amine and 1 mole of pyromellitic anhydride. The reaction is carried out without solvent at 150 ° C with stirring under a nitrogen blanket for 6 hours.

27 90 349

The following characteristics were then measured for the female fuels: (i) Fuel capacity from the blades of the diesel fuel main filter at -9 ° C, and the percentage of wax in the filter blade with the following results:

Additive Clogging consumption% wax passed _ nut time_ _ E 11 minutes 18-30% F 16 minutes 30% G Not clogged 90-100% H 15 minutes 25% I 12 minutes 25% J 9 minutes 10% (ii) Pressure drop the time determined in the main filter is shown graphically in Figure 7.

(i i i) The settling of the wax in the fuel was measured by cooling the fuel in a 100 ml volumetric flask with a top surface corresponding to 100% of the fuel height. The beaker is cooled to 1 ° C / hour from the outlet temperature, which is preferably 10 ° C above the fuel cloud point, but not less than 5 ° C above the fuel cloud point, to the test temperature, which is then maintained for a predetermined time. The test lamp state and the precipitation time depend on the application, i.e. diesel or fuel oil. The test lamp room is generally 5 ° C below the cloud point, and the minimum time for cold precipitation in the test lamp room is at least 4 hours. The test lamp temperature should preferably be 10 ° C or more below the cloud point of the fuel, and the precipitation time should be 24 hours or more.

At the end of the precipitation time, check the beaker, measure the height of any precipitated wax visually above the bottom of the beaker (0 ml) and express it as a percentage of the total dimension (100 ml). Above the precipitated wax crystals 28,90349, clear fuel is visible, and this method of measurement is often sufficient to assess wax precipitation. Often the fuel is cloudy above the precipitated wax crystals, or the wax crystals appear to be denser than they are when approaching the bottom of the measuring glass. In that case, a more quantitative method of analysis is used. Carefully suck and store the top 5% (5 ml) of that fuel, suck the next 45%, discard, suck and store the next 5%, suck the next 35% and discard, and finally recover the bottom 10% to dissolve the wax crystals. after heating. Samples recovered after this are treated as surface, middle and bottom samples, respectively.

It is important that the vacuum used in the suction is rather weak, i.e.

200 ml of water, and that the pipette tip is placed just on the surface of the fuel in order to avoid currents in the liquid which could interfere with the wax concentrations in the different layers inside the beaker. The samples are then warmed to 60 ° C for 15 minutes and examined with a differential scanning calorimeter as mentioned elsewhere in this text.

DSC technology eliminates the need for a device such as the Dupont 9900 Series or Mettler TA 2000B. The latter device was used here. 25 μl of the sample is placed in the sample cell, and ordinary kerosene is placed in the reference cell and cooled at a rate of 22 ° C / minute from 60 ° C to at least 10 ° C, preferably above 20 ° C above the wax detection lamp (WAT), and then cooled for 2 ° C / minute about 20 ° C below WAT. The reference sample is run on non-precipitated uncooled fuel. In this case, the precipitation of the wax corresponds to WAT (or WAT = WAT precipitated sample - WAT original sample). Negative results indicate wax removal from the fuel, and positive values indicate wax enrichment by precipitation. The wax content can then be considered as a measure of precipitation in female samples. This is expressed as% WAX or 4% WAX (Δ% WAX =% wax in the precipitated sample -% wax in the original sample), again negative values of 29 90349 indicate wax removal from the fuel and positive values indicate wax enrichment by precipitation. These wax concentrations are derived by measuring the area under the DSC curve up to the specified temperature.

The fuel wax was cooled from 1 ° C / hour from + 10 ° C to -9 ° C and kept there for 48 hours before testing. The results were as follows:

Additive Visible wax Surface 5% WAT ° C values_ ____ _ _ Middle part 5% Bottom part 10% E Leaf cloudy, -10.80 -4.00 -3.15 on the base ti-better F On the surface 50% -13.35 -0, 80 -0.40 clear G 100% -7.85 -7.40 -7.50 H Surface 35% -13.05 -8.50 +0.50 clear I Surface 65% - clear J 100% semi- - 6.20 -6.25 -6.40 jellies (These results are also shown graphically in Figure 8).

Original WAT _WAT (° C) (Precipitated samples)

Unprecipitated Surface 5% Middle 5% Bottom 10% combustion_ _ ___ J__ E -6.00 -4.80 +2.00 +2.85 F -5.15 -8.20 +4.35 +4.75 G - 7.75 -0.10 +0.35 +0.25 H -5.00 -8.05 -3.50 +4.50 J -6.20 0.00 -0.05 -0.20 (Note that the most effective additive (G) can cause a marked decrease in WAT).

30 90 349% WAX (Precipitated samples) _

Surface 5% Middle section 5% Bottom 10% E -0.7 +0.8 +0.9 F -0.8 +2.1 +2.2 H -1.3 -0.2 +1.1 G + 0.0 +0.3 +0.1 J -0.1 +0.0 +0.1 (Note:% WAX has been measured by applying the original baseline and measuring the area WAT from -25 ° C to The calibration has been carried out on waxes which crystallize on the known front of the roof) ·

The results show that the crystal size has decreased due to the presence of additives, the wax crystals settle relatively quickly. For example, when untreated fuels are cooled below their cloud point, they tend to show a small settling of the wax crystals because the plate-like crystals adhere to each other and cannot form a free-flowing liquid, but when the shape becomes less plate-like and tends to form a few tens of micrometers long needle-like crystals that can move freely in the liquid and settle relatively quickly.

This settling of wax crystals can cause problems in storage containers and vehicle systems. Condensed wax layers can be inadvertently absorbed into the system, especially when the fuel level is low or the tank mixes (e.g. when the vehicle is cornering), and the filter can become clogged.

If the size of the wax crystals can be reduced to less than 10,000 nanometers, the crystals settle relatively slowly, and this can lead to non-settling of the wax, which gives advantages in terms of fuel properties compared to the case where the fuel contains precipitated wax crystals. If the size of the wax crystals 31,90349 can be reduced to below 4000 nanometers by the inventor, the tendency of the crystals to settle in the fuel storage is almost eliminated. If the size of the wax crystals is reduced to the optimum size of the claims, the permanent wax crystals remain in the fuel soaked for many weeks as required in some storage systems, and the problems are effectively eliminated.

(iv) The CFPP characteristics were as follows:

Additive CFPP Temperature Decrease in CFPP E -14 11 F -20 17 G -20 17 H -20 17 I -19 16 -3 (v) The average crystal size formed was found to be:

Additive Size (Nanometry) E 4400 F 10400 G 2600 H 10800 T 8400 J Thin plates, middle ground 50000

Claims (5)

32 90349 1. Distilled fuel oil boiling in the range of 120 to 500 ° C, characterized in that it has a wax content of at least 0.3% by weight below the wax manifestation temperature of 10 ° C, and that at this temperature the average crystal size of the wax crystals is less than 4000 nanometers. Distilled fuel according to Claim 1, characterized in that the average crystal size of the wax crystals is less than 3000 nanometers. Distilled fuel according to Claim 1, characterized in that the average crystal size of the wax crystals is less than 2000 nanometers. Distilled fuel according to Claim 1, characterized in that the average crystal size of the wax crystals is less than 1500 nanometers. Distilled fuel according to Claim 1, characterized in that the average crystal size of the wax crystals is less than 1000 nanometers. 33 9 0 3 4 9