CN1025347C - Middle distillate compositions with reduced wax crystal size - Google Patents

Abstract

The invention relates to a distillated fuel oil with a boiling point from 120 DEG C to 500 DEG C. In temperature below 10 DEG C of wax occurrence, the content of the wax is at least 0.3 percent (weight). In the temperature, average granularity of wax crystal is less than 4000millimicron, preferably less than 1000millimicron. 159:02) (C10M109:00) C10N40:00.

Description

Middle distillate compositions with reduced wax crystal size

The present invention relates to improved distillate fuel oil.

As the mineral oil that contains paraffin (as distillate fuel) of diesel engine oil and warming oil, when the temperature of oil reduced, their flowability had the trend that reduces.The loss of its mobility is because wax crystallization slabbing crystal, and this tabular crystal finally forms sponge block, and oil is wrapped in wherein.Temperature when the wax crystalline substance begins to form is called cloud point; The temperature that wax stops oil to pour into is called pour point.

Some additive when they and content of wax mineral oil, can be used as the pour point depressant of pour point.

These composition changes the size and the shape of wax crystalline substance, reduced force of cohesion between crystal and the bonding force between crystal and the oil, keep the low temperature fluidised form to cause oil, thereby can pour into and can pass through strainer.

Narrated various pour point pour point depressant in the document, some of them have had supply of commodities.For example United States Patent (USP) № 3,048,479th, and the pour point depressant that acts as a fuel with the multipolymer of the vinyl acetate (for example vinyl-acetic ester) of the acid of ethene and 1～5 carbon especially for heating oil, diesel engine oil and jet engine oil.Based on the hydro carbons polymerization pour point depressant of ethene and more senior alpha-olefin (for example propylene), also be known.United States Patent (USP) 3,252,771st, is used for U.S. sixties early stage " wide boiling range ", easily handles the distillate fuel of type as the pour point pour point depressant with the polymkeric substance of the alpha-olefin of 16～18 carbon and aluminum chloride/alkyl fontanel catalyzer.At the later stage sixties and the initial stage seventies, emphasize to improve oil filtration performance between cloud point and pour point temperature, stop up point (CFPP) test (IP309/80) with strict low-temperature filter and measure.After this many relevant patents of improving the additive of fuel performance (with this method test) have been issued.United States Patent (USP) 3,961,916th, the size of the mixture control wax crystalline substance of usefulness multipolymer.English Patent 1,263,152 propose, and the big or small available of wax crystalline substance has the multipolymer of rudimentary side chain to control.

Such suggestion is also arranged: for example English Patent 1,469,016 proposes, fumaric acid di n-alkanyl ester/the vinyl acetate copolymer that is used as lubricating oil pour point pour point depressant can be used as common additive and handles the distillate fuel of high end point with ethylene/acetic acid ethyl ester multipolymer, so that improve their low-temperature fluidity.

Also there is suggestion to use based on the additive of alkene/maleic anhydride copolymers.For example United States Patent (USP) 2,542, and 542 use the alkene (as vaccenic acid) and the multipolymer of maleic anhydride to use alcohol (as lauryl alcohol) esterification as the pour point pour point depressant.English Patent 1,468,588 use the multipolymer common additive of behenyl alcohol esterification as distillate fuel of 22～28 carbon olefins and maleic anhydride, equally, Japanese patent gazette 5,654,037 use alkene/copolymer-maleic anhydride after reacting with amine as the pour point pour point depressant.

Japanese patent gazette 5,654,038 uses cut FLOW IMPROVERS (as ethylene) in alkene/copolymer-maleic anhydride and the routine.Japanese patent gazette 5,540,640 disclose use alkene/maleic anhydride copolymers (no esterification) as the pour point pour point depressant, and narrated the carbonatoms that employed alkene contains should be greater than 20, so that obtain the CFPP activity.English Patent 2,192,012 uses the alkene/maleic anhydride copolymers of some esterification and the mixture of low molecular weight polyethylene.During as independent additive, the multipolymer of esterification is invalid.

After in fuel, adding the described additive of these patents, owing to changed the size and the shape of wax crystalline substance, the major part that produces is acicular crystal, usually its granular size is 10,000 millimicron or bigger, typical person is 30,000 to 100,000 millimicron, thereby reached the active purpose of improvement CFPP.When diesel engine is worked under low temperature, these crystal are the paper type oil filter by vehicle not, but on purolator, form permeable cake piece, make liquid fuel can pass through purolator, after engine and fuel heating, the wax crystalline substance just melts thereupon, promptly when round-robin fuel has heated most fuel.But the heap of wax may be blocked filter paper, makes the difficulty of starting to produce difficulty and winter driving of diesel engine vehicle, also can cause the problem of fuel-heating system.

We find uncannily now, add some additive and can obtain the brilliant enough little waxy fuel of wax, can be by being generally used for the papery main fuel filter in the diesel engine when low temperature.

Therefore, the invention provides boiling range and be 120～500 ℃ distillate fuel oil, its wax content is at least 0.3(weight under the temperature that 10 ℃ of temperature appear in wax being lower than) %, the mean particle size of wax crystalline substance is lower than 4,000 millimicrons under this temperature.

It is to measure with differential scanning formula calorimetry (DSC) that temperature (WAT) appears in the wax of fuel.This test method(s) be with a fuel sample (25 microlitre) with the cooling of 2 ℃/minute speed, test simultaneously similar thermal capacity is arranged but in the temperature range of research the non-setting reference sample of wax (as kerosene).When beginning crystalline polamer is arranged, sample can observe exothermic phenomenon.Can measure the WAT of fuel with extrapotation with Metter TA 2000 B differential scanning formula calorimeters.

The area integral that the content of wax can be surrounded the above DSC track of baseline calculates, and specific temperature is reduced in heat release.Crystalline wax with known quantity is demarcated in advance.

The mensuration of the mean particle size of wax crystalline substance is to analyze the scanning electron photomicrograph of the fuel sample of amplifying 4,000 to 8,000 times, and measures at least 44 longest dimension in 88 that are scheduled on the grid.We find, if the particulate mean sizes is less than 4,000 millimicron, wax will begin by typically being used for the paper type oil filter of diesel engine, though the particle size that we select is 3 with fuel, below 000 millimicron, preferably be lower than 2,000 millimicrons, very cause and be lower than 1500 microns, particularly be lower than 1000 millimicrons, just can make the wax crystalline substance obtain real benefit by paper type oil filter.The particulate actual size depends on the original character of fuel and the character and the consumption of additive.We find that these sizes and littler size can reach.

In fuel, to obtain so little wax crystalls, operability to diesel engine has great benefit, can be with following described fact proved: the fuel that stir are made it by V.G.Golf or Cummins diesel engine purolator filter paper with pump with 1.0～2.4 liters of 8～15 milliliters of every square metre of filter paper p.s.s and per minutes, its temperature is lower than wax and at least 5 ℃ of temperature occur, wherein has 0.5(weight at least) fuel of % is the form of solid wax.If satisfy one or more standards what follows, fuel and wax all can be thought and successfully passed through purolator.

(ⅰ) pass through purolator with 18～20 liters of fuel, the pressure of purolator falls and is no more than 50 kPas (KPa), and preferably 25KPa is more preferably 10KPa, and that especially preferentially select is 5KPa.

(ⅱ) having 60%, preferably at least 80% at least, all by weight with 90%(at least) wax (by above-mentioned DSC test determination) that exists in the crude fuel is present in the fuel that has passed through purolator.

(ⅲ) make 18～20 liters fuel pass through purolator with pump, its flow velocity often remains on more than 60% of initial flow rate, preferably more than 80%.

The crystal that passes through the vehicle purolator that has improved owing to fine crystals and the runnability of engine are mainly to depend on crystalline length, though the crystalline shape is also very important.We find that cubic crystal is easier slightly than flat crystal by purolator, and are when they do not pass through, usually also less to the resistance to flow of fuel.But crystal is a flats preferably, when temperature descends, has more wax to become crystal on the principle, therefore, is reaching before the critical crystal length, gets more than the cube crystal settling of equal length.

Fuel of the present invention is compared with the distillate fuel that improves its low-temperature fluidity with the conventional additives that adds before, and advantage is outstanding.Fuel of the present invention also has improved low-temperature startup performance, but it and the circulation that do not rely on hot fuel are to remove the deposition of dewax.And the wax crystalline substance trends towards keeping being suspended in the fuel, and can not form one deck wax layer in basin, as using the conventional additives processing phenomenon that fuel produced.Thereby its distributivity is better.Compare with the fuel that contains conventional additives, fuel of the present invention is everlasting has improved runnability in the low temperature CDY Chassis Dynamometer test.In many examples, this fuel also has improved CFPP performance.

Boiling point is at the distillate fuel of 120 ℃ to 500 ℃ general category, and the content of its boiling point characteristic, distribution of normal alkanes and wax all has very big difference.The fuel in Northern Europe generally full boiling point and the cloud point than the fuel in southern Europe is all low, and the general high 1.5%(of wax content is below WAT 10 ℃ the time).Because of separately climate relationship similar difference is arranged also from the fuel of other countries in the world, but its wax content also depends on the source of crude oil.The fuel the wax content roughly recently Chinese freely or fuel that Australian waxy crude oil is made that derives from middle-eastern crude will hang down.

The degree that can access fine crystals is decided by the character of fuel itself, can not produce minimum crystal of the presently claimed invention in some fuel.As run into this situation, and can regulate the refinery condition and make it to use suitable additive, change the characteristic of fuel, make it can obtain so little crystal.

The preferential additive of selecting is the compound with following general formula:

In the formula-Y-R ²Be SO ^{(-) (+)} ₃NR ³ ₃R ²,-SO ^{(-) (+)} ₃HNR ³ ₂R ²,

-SO ^{（-）（+）} ₃H ₂NR ³R ²，-SO ^{（-）（+）} ₃H ₃NR ²，

-SO ₂NR ³R ²Or-SO ₃R ²;

-X-R ¹For-Y-R ²Or-CONR ³R ¹,

-CO ^{（-）（+）} ₂NR ³ ₃R ¹，-CO ^{（-）（+）} ₂HNR ³ ₂R ¹，

-CO ^{（-）（+）} ₂H ₂NR ³R ¹，-CO ^{（-）（+）} ₂H ₃NR ¹，

-R ⁴-COOR ₁，-NR ³COR ¹，

R ⁴OR ¹，-R ⁴OCOR ¹，-R ⁴R ¹，

-N(COR ³) R ¹Or Z ^{(-) (+)}NR ³ ₃R ¹;

-Z ^(-)Be SO ^(-) ₃Or-CO ^(-) ₂;

R ¹And R ²The poly-alkoxyalkyl that contains at least 10 carbon atoms for alkyl, alkoxyalkyl or main chain;

R ³Be alkyl, each R ³Can have nothing in common with each other or identical R ⁴Be the alkylidene group of 1～5 carbon or do not represent any group,

In carbon-to-carbon (C-C) key be a) ethylene unsaturated bond (when A and B may be for alkyl, alkenyl or substituted alkyl) or b) can be the part ring texture of aromatics, polynuclear aromatic or cyclic aliphatic.That preferentially select is X-R ¹And X-R ²Between contain the group of at least 3 alkyl, alkoxyalkyl or poly-alkoxyalkyl.

Annular atoms on this kind ring compound is carbon atom preferably, but also can comprise-N, S or Sauerstoffatom become heterogeneous ring compound.

The example that can prepare the fragrant parent compound of additive is

Aryl wherein is can be substituted; They also can make from polynuclear compound, the compound of promptly desirable various forms of two rings or polynuclear plane, and they can be (a) fused benzene rings; (b) the condensed ring structure of non-benzene or non-whole phenyl ring; (c) ring that links of tail end; (d) heterogeneous ring compound; (e) non-aromatics or fractional saturation ring system or (f) three-dimensional structure.

The example that condenses the benzene structure of above-claimed cpd of can deriving comprises naphthalene, anthracene, phenanthrene and pyrene.

The example of the condensed ring structure of non-benzene or non-whole phenyl ring comprises

, indenes, hydrogen indenes, fluorenes, diphenylene.The example of the ring compound that tail end links comprises biphenyl.The example of suitable heterocycle that can derivative compound comprises quinoline, pyrindine, indoles, 2,3-indoline, cumarone, tonka bean camphor, Isocoumarin 〉97, thionaphthene, carbazole and thiophene piperazine.The non-aromatics that is fit to or the ring system of fractional saturation comprise naphthalane (perhydronaphthalene), α-Pai Xi, cadinene, bornylene.The example of the three-dimensional compound that is fit to comprises norbornylene, norbornane (norbornane), double-octane and dicyclo octene.Substituent X and Y must be connected (if monocycle) on the adjacent ring atom of ring or be connected on the adjacent ring atom on the ring of polynuclear compound.The latter means promptly that when using naphthalene this di-substitutedly can not be connected 1, and 8-or 4 on the 5-position, but is connected 2,3-, and 3,4-, 5,6-, 6,7-or 7 is on the 8-position.

These compounds can generate ester, amine, acid amides, half ester/half amide, half ether or the salt as additive after reaction.The preferential additive of selecting is a secondary amine salt, and they have a hydrogeneous and carbonaceous group, or contains at least 10, the best group of at least 12 carbon atoms.This kind amine or salt can react with aforementioned acid or with amine and prepare, or produce with secondary amine derivative and carboxylic acid or anhydride reaction.Prepare acid amides by acid and need remove moisture and heating usually.Other method is the mixture phase reaction that carboxylic acid and is contained alcohol or the alcohol and the amine of at least 10 carbon atoms.

The preferential hydrogeneous and group of selecting carbon is an alkyl in the substituent, though available fontanel, preferably only contains the fontanelle atom (for example chlorine atom) than small proportion for alkyl, for example less than 20(weight) %.The preferential alkyl of selecting is an aliphatic alkyl, alkylidene group for example, preferably straight chain.Can use undersaturated alkyl, alkene for example, but be not that preferential the selection used.

The preferential alkyl of selecting has at least 10 carbon atoms, 12～22 carbon atoms preferably, the alkyl of 14～20 carbon atoms for example, and preferably straight chain or on 1-or 2-position, side chain is arranged.Surpass 20% alkyl chain as branching, then side chain must be a methyl.Other are hydrogeneous can be to lack with group carbon, and for example being less than 6 carbon atoms maybe can have at least 10 carbon atoms (as needs).The alkyl that is fit to comprises methyl, ethyl, propyl group, hexyl, decyl, dodecyl, tetradecyl, larane base and docosyl (sweet potato base).The alkylidene group that is fit to comprises hexylidene, octylene, inferior dodecyl and inferior hexadecyl, but all non-preferential selections of these groups.

In optimum implementation, the reaction of intermediate and secondary amine, one of preferential substituent of selecting will be an acid amides, other will be the dialkyl ammonium salt of amine or secondary amine.The preferential especially additive of selecting is the amine salt of acid amides and secondary amine.

For producing fuel of the present invention, these additives generally will be used in combination with other additive.The example of other additives comprises that those are referred to as the additive of " comb " shaped polymer, and its general formula is as follows:

D=R in the formula, CO.OR, OCO.R, R ' CO.OR or OR

E=H or CH ₃Or D or R '

G=H, or D

The m=1.0(homopolymer)～the 0.4(mol ratio)

J=H, R ', aryl or heterocyclic radical, RCO.OR

K＝H，CO.OR′，OCO.R′，OR′，CO ₂H

L=H, R ', CO.OR ', OCOR ', aryl, CO ₂H

N=0.0～0.6(mol ratio)

R≥C ₁₀

R≥C ₁

Can carry out trimerization with another monomer when needing.

Other additives that consist of alpha-olefin and copolymer-maleic anhydride are easy to preparation: monomer is carried out solvent-free polymeric or carry out polymerization in the solution of hydrocarbon (as heptane, benzene, hexanaphthene or white oil) solvent; temperature is generally 20～150 ℃; superoxide commonly used or azo class catalyzer (as benzoyl peroxide or Diisopropyl azodicarboxylate) promote reaction, carry out under rare gas element (as nitrogen or carbonic acid gas) protection (eliminating oxygen).Though the mol ratio that is fit to of alkene and maleic anhydride is 2: 1 to 1: 2, using the alkene and the maleic anhydride of equimolar amount is preferably, and this is not main.Can 1-decene, 1-dodecylene, tetradecene, cetene, 1-vaccenic acid be arranged with the example of the alkene of maleic anhydride copolymerization.

Alkene and copolymer-maleic anhydride can carry out esterification with any suitable technology.Though maleic anhydride have at least 50% esterified be preferably, be not main.The example of spendable alcohol comprises nonylcarbinol, n-dodecanol, positive tetradecyl alcohol, positive hexadecanol, positive stearyl alcohol.The chain of alcohol can comprise 1 methyl branch, for example 1-methyl pentadecylic alcohol, 2-methyl tridecyl alcohol.Used alcohol also can be the mixture of the alcohol of a n-alkanol and a methyl-branched.Each alcohol all can be used to the multipolymer of esterification maleic anhydride and any alkene.Preferably use pure alcohol and do not use commercially available alcohol mixture, if but use mixture, then R ¹Represent average carbon atom number in the alkyl; If use the alcohol that side chain is arranged on 1-or the 2-position, then R ¹Represent the straight chain carbon skeleton of alcohol.When using mixture, importantly be no more than R ¹15% of base has R ¹+ 2 value.The alkene with the maleic anhydride copolymerization is depended in the selection of alcohol naturally, so that R+R ¹In 18 to 38 scope.The preferential R+R that selects ¹Value depends on that needs add the boiling point characteristic of the fuel of additive.

Comb-shaped polymer also can be the multipolymer of being narrated in fumaric acid polymkeric substance and applicant's the european patent application 0513176,0513177,85301047 and 85301048.Other comb-shaped polymers that are fit to are the polymkeric substance of alpha-olefin and the styrene and maleic anhydride of multipolymer and esterification.

Can polyoxy alkylidene ester, ether, ester/ether and their mixture be arranged with the example of shared other interpolation of ring compound, particularly those contain at least one, preferably the linear saturated alkyl and the molecular weight of at least two 10～30 carbon are 100～5,000, preferably 200～5, the poly (oxyalkylene) based compound of 000 polyoxyalkylene glycols, the alkyl in polyoxyalkylene glycols contain 1～4 carbon atom.These materials have constituted European patent 0.061, the theme of 895B.Other examples of such additives is described in United States Patent (USP) 4,491,455.

The preferential ester that is used for the present invention, ether or the ester/ether of selecting can be used formula

Make structure and set forth R in the formula and R " can be identical or inequality, can be:

ⅰ) normal chain alkyl

Alkyl is linear saturated, contains 10～30 carbon atoms, and A represents the poly (oxyalkylene) base section of glycol, and wherein alkylidene group has 1～4 carbon atom, and as polyoxymethylene, polyoxyethylene or polyoxy trimethylene, they are actually linear; Can allow the low alkyl group side chain branching to a certain degree of (as in the polyoxy trimethylene glycol), but preferably glycol should come down to linearity; A also can be nitrogenous.

Often for coming down to linear polyoxyethylene glycol (PEG) and polypropylene glycol (PPG), molecular weight is about 100～5,000 to the glycol that is fit to, and preferably about 200～2,000.Ester class additive is preferential the selection, the lipid acid that contains 10～30 carbon atoms is the useful lipid acid that forms ester additive with the glycol reaction, esterification is carried out in the preparation of preferably using the lipid acid of 18～24 carbon, particularly sweet potato, the ester also lipid acid of available polyethoxylated or the alcohol of polyethoxylated.

Polyoxy alkylidene diester, diether, ether/ester and their mixture are the additives that is fit to, and diester is preferably used in narrow-boiling range fraction; Also have simultaneously monoether in a small amount and monoesters and exist, and form in the production process of being everlasting.It is very important for the additive performance that the dialkyl compound existence of main amount is arranged, and particularly the stearic acid or the sweet potato acid esters of poly-ethylidene glycol, polytrimethylene glycol or poly-ethylidene/polytrimethylene glycol mixture are the preferential compounds of selecting.

Employed additive also can contain ethene unsaturated ester multipolymer FLOW IMPROVERS, can comprise the unsaturated monoesters and the diester of following general formula with the unsaturated monomer of ethylene copolymer

R in the formula ₅Be hydrogen or methyl; R ₆For-OOCR ₈Base, R wherein ₈For hydrogen or 1～28 carbon, relatively more commonly used be 1～17 carbon, it is preferential that what select is the straight or branched alkyl of 1～8 carbon; Perhaps R ₅For-COOR ₈Base, R wherein ₈Be preceding address but and non-hydrogen group; R ₇For hydrogen or as defined above-COOR ₈Base.R ₆And R ₇Be hydrogen, R ₅For-OOCR ₈The time, monomer comprise 1～29 carbon, commonly used be the ethene alcohol ester of the monocarboxylic acid of 1～18 carbon, preferential select be 2～29 carbon, commonly used be the ethene alcohol ester of the monocarboxylic acid of 1～18 carbon, the particularly monocarboxylic acid of 2～5 carbon.Can comprise vinyl-acetic ester, propionate, vinyl butyrate or isopropylformic acid vinyl acetate with the example of the vinyl acetate of ethylene copolymer, preferential what select is vinyl-acetic ester.

When using these esters, multipolymer preferably contains 5～40(weight) %, preferentially select 10～35(weight) vinyl acetate of %.Also can use United States Patent (USP) 3,961, the mixture of two kinds of multipolymers described in 916.Preferably the molecular-weight average of these multipolymers (measuring by the vapor phase osmose process) is 1,000 to 10,000, preferentially selects 1,000 to 5,000.

Used additive also can contain other polar compounds, ionic or non-ionic, and they play the wax crystal growth hold back agent in fuel.When being used in combination with diol ester, ether or ester/ether, the polarity nitrogenous compound has good especially effect.The amine that these polar compounds are normally replaced by the alkyl of 1 molar ratio at least and the amine salt and/or the acid amides that 1～4 carboxylic acid group's hydrocarbon is sour or its anhydride reaction forms that have of 1 molar ratio.Contain 30～300 altogether, preferably ester/the acid amides of 50～150 carbon atoms also is operable.These nitrogenous compounds are described in United States Patent (USP) 4,211, in 534.The amine that is fit to normally long-chain 12～48 carbon primary, second month in a season, uncle, quaternary amine or their mixture, but also can use amine than short chain, need only resulting nitrogenous compound and be oil-soluble and under normal circumstances contain 30～300 the total carbon atoms of having an appointment.The alkyl chain that nitrogenous compound preferably contains 8～24 carbon of at least one straight chain breaks.

The amine that is fit to comprises primary, the second month in a season, uncle, quaternary amine, preferentially selects secondary amine.Tertiary amine and quaternary amine can only form amine salt.The example of amine comprises 14 carbon amine, coconut amine, tallow amine and analogue secondary amine etc.The mixture of amine also is fit to, and all is mixture from the many amine of natural product deutero-.The preferential amine of selecting is the secondary hydrogenated tallow amine, and molecular formula is HNRR, and wherein R and R are derived and next alkyl by hydrogenation ox ester, and the composition of hydrogenated tallow is about 4% 14 carbon, 31% 16 carbon, 59% 18 carbon.

The example for preparing the carboxylic acid (with its acid esters) that is fit to of these nitrogenous compounds comprises hexanaphthene-1,2-diacid, tetrahydrobenzene-1,2-diacid, pentamethylene-1,2-diacid, naphthalene diacid etc.Usually, nearly 5～13 carbon atoms on the ring of these acid.The acid that is used for the present invention's preferential selection is that phthalic acid is (as phthalic acid, m-phthalic acid and terephthalic acid.Phthalic acid or its acid anhydride are preferential especially the selections.The preferential especially compound of selecting is acid amides-amine salt, is formed by 1 mole of phthalic anhydride and 2 mole of two (hydrogenation ox ester) amine.Another preferential compound of selecting is a diamide, is that acid amides-amine salt dehydration forms thus.

Hydrocarbon polymer also can be used as the part of compositions of additives to produce fuel of the present invention.This base polymer can be represented with following general formula:

T=H or R ' in the formula

U=H, T or aryl

V=1.0～0.0(mol ratio)

W=0.0～1.0(mol ratio)

R ' is for containing the normal chain alkyl of 10 above carbon atoms.

The polymkeric substance that this base polymer can directly be prepared by ethylene unsaturated monomers or be generated by other monomers (as different propylene and divinyl) indirectly carries out hydrogenation and produces.

The preferential especially hydrocarbon polymer of selecting is the multipolymer of ethene and propylene, and the content of therein ethylene is between 50% to 60% (w/w) preferably.

The required additive capacity of production distillate fuel oil of the present invention is different according to the difference of fuel, generally is 0.001～0.5(weight) %, for example 0.001～0.1(weight of weight of fuel) the %(active substance).Additive can conveniently be dissolved in suitable solvent and form 20～90(for example 30～80) enriched material of the concentration of weight percent.The solvent that is fit to comprises kerosene, aromatic series petroleum naphtha, mineral lubricating oils etc.

The present invention is with the explanation of following example, and the mensuration of the size of wax crystalline substance is 2 ounces the bottle that fuel sample is placed ice chest in the fuel, remain on the fuel cloud point above about 8 ℃ 1 hour, make the temperature-stable of fuel.Ice chest cools off with 1 ℃ speed per hour, until test temperature, keeps this temperature then.

Then, one ready-formed filter-carrier is positioned on the vacuum unit, said prefabricated filter-carrier is that 10 millimeters sintered ring is formed by a diameter, have around this ring one wide be 1 millimeter annular metal circle, and supporting 200 millimicrons silver membrane filter, this strainer is located by two vertical leg.Adopt the vacuum tightness of 80KPa at least, drip refrigerative fuel from a suction pipe that cleans to this film, till top, garden pitting just covers this silverskin.Slowly splash into this fuel to keep this pitting; Splash into after about 10～20 oil drippings, this pitting is drained, on this film, stay a dim coarse wet wax stone thin layer.The wax of thick-layer can not wash, and thin layer wax can be rinsed.Best bed thickness is the function of crystal shape, and " lobate " crystalline layer needs thinner than having " granular " crystalline layer.Importantly final gatch will have coarse outward appearance.The gatch of " glossy " shows residual excessive fuel, and crystalline " profile is unclear " should be discarded.

Then, with obtaining gatch above several methylethylketones cleanings, methylethylketone drop fully falls.Said process is repeated for several times.When cleaning was finished, methylethylketone wherein was with very fast disappearance." the coarse white of the light " surface that stays one, this surface are on dripping during another methylethylketone, with grizzle.

Then, the sample that cleaned is positioned in the cool-drying device, preserves up in scanning electronic microscope, applying.Have and necessary this sample kept freezing to preserve wax, in this case, shift (with a suitable sample transfer container) in the scanning electronic microscope before, should hold it in the cold box, in order to avoid on this sample surfaces, form ice crystal.

When applying, must make this sample keep cold as much as possible, so that the crystalline damage is reduced to minimum degree.Preferably making endless loop be pressed in the Stage microscope concave edge by retaining screw provides and the electrically contacting of Stage microscope, and the design of Stage microscope can make the surface of sample be on the focusing surface of instrument.Also can use electroconductive paints.

Coated with after, just can on scanning electronic microscope, obtain Photomicrograph with ordinary method.Analyze Photomicrograph to measure the crystal mean sizes, method is that a slide is fixed on the suitable Photomicrograph, and slide has the grid infall of 88 points (with mark) at 8 rows, 11 row that clocklike are evenly distributed.Its ratio of enlargement should make the crystal of several maximums be contacted by the point more than, amplifies 4000～8000 times and proves suitable.On each grid point of crossing, if the point on it touch one can clear definite crystalline size, this crystal can be determined.Also can adopt Gauss (Gauss) standard deviation form, and measure with Bezier (Bessel) gauged " scattering " with crystal length.

Measure wax content before and after the purolator and be to use differential scanning formula calorimeter (DSC) (Du Pont's 9900 series for example, it can obtain a graphic representation, its area is about 1% the fuel that 100cm/ represents with the wax form, has standard error to bring out output less than 2% instrument noise of average output signal and changes.

The demarcation of DSC is can guarantee by the purolator filtering to produce big crystal with a kind of additive, under the test temperature at rig-testing this WAT that demarcates fuel and on DSC, measure this dewaxed fuel.On DSC, analyze the groove oil and the filter back fuel sample of desire test then,, analyze the WAT of the above area of baseline until the demarcation fuel of measuring for each fuel.

(the DSC area of filtering sample)/(the DSC area of groove oil samples) * 100%=filters the percentage composition of the remaining wax in back.

Measure the cloud point of distillate fuel with standard cloudy test (IP-219 or ASTM-D2500), other begins to occur measuring as crystallization is with wax appearance point (WAP) test (ASTM3117-72), and it is to measure with Mettler TA 2000 B differential scanning formula calorimeters with the differential scanning method that temperature (WAT) appears in wax.

Ability by Diesel's vehicle main fuel filter is to measure in the device of the typical Diesel's vehicle main fuel filter in comprising the standard valve casing that is contained on the oil circuit; The Basch type is used for 1980VW Golf Diesel passenger vehicle; It is suitable that Cummins FF105 is used for Cummins NTC power team.The oil tank of half oil mass of use energy supply standard oil groove and oil supply system are connected in just like the used fuel filling pump of VW Golf and make it pass through purolator with constant flow rate from the oil tank oil pumping, as in the vehicle, with various instruments with the pressure of measuring purolator fall, the flow rate of filling pump and the temperature of system.Reclaim the oil that pumps, the i.e. oil of " injection " and excessive oil with storage tank.

In this test, inject oil groove and make leak test with 19 kilograms fuel.After qualified, oily temperature is stabilized under the air themperature that is higher than 8 ℃ of fuel cloud points.Then this device is cooled to desired test temperature with 3 ℃/hour speed, placed at least 3 hours afterwards so that fuel temperature is stable.The wax that violent shake oil groove exists with abundant dispersion; From the oil groove sampling, and from taking out 1 liter of fuel and send oil groove back near the sampling spot on the delivery pipe of oil groove.

Start pump then, pump speed is scheduled the pump speed (rpm that is equivalent under the 110kph travel speed.Under the situation of VW Golf, this pump speed is 1900rpm, is equivalent to the motor speed of 3800rpm.Pressure on the monitoring purolator falls and from the oily flow velocity that filling pump comes out, till running out of gas, generally needs 30～35 minutes.

If supply with the fuel of oil nozzle can be fixed on the 2ml/sec(excess of fuel will be 6.5～7ml/sec) time for about, the result is " qualified "; The fuel flow rate of supplying with oil nozzle descends and represents " border " result; Not having flows is " defective ".

Generally, the possibility of result of " qualified " is relevant with the rising that purolator pressure falls, and it may be raised to 60KPa.Reach such result, generally must have the wax of significant proportion to pass through purolator.Good " qualified (GOOD PASS) " is that the not test of super 10KPa of rising falls in the pressure of purolator, this be most of wax first of logical oiling device indicate, excellent results be reduced to 5KPa.

Test (the test whole process, getting a sample with per 4 minutes is ideal) from " excess of fuel " and " oil nozzle " sampled fuels again.These compare with DSE with the oil groove sample of prerun like this, determine the ratio by the charging wax of purolator, get the prerun fuel sample simultaneously and after test with they preparation SEM samples, with the real-world operation relatively size and the type of wax.

The additive that uses has:

Additive 1

The N of 2-dialkyl amide base Phenylsulfonic acid, the N-dialkyl ammonium salt, wherein alkyl is positive C _16-18H _33-37, it is by being that two (hydrogenated tallow) amine is 50%(w/w in concentration with 1 mole adjacent iodo-benzoic acid cyclic anhydride and 2 moles) under in xylene solvent prepared in reaction.At 100 ℃ to stirred reaction mixture between the reflux temperature.Solvent and reagent should keep dry as far as possible, avoid acid anhydride to be hydrolyzed.

With 50MHz nuclear magnetic resonance analyser assay products, determine that its structure is

Additive 2

The multipolymer of ethene and vinyl-acetic ester, content are 17%(weight), molecular weight is 3500, measuring its degree of branching with 500MHzNMR is that per 100 methylene radical must have 8 methyl.

Additive 3

Ethylbenzene-the copolymer-maleic anhydride that with mol ratio is 1: 1 is with 1 of 2 moles of every mole of anhydride group: the C 1(mole) ₁₂H ₂₅OH and C ₁₄H ₂₉OH mixture (excessive slightly, 5% alcohol) carries out esterification, with tosic acid (1/10 mole) make catalyzer, dimethylbenzene is made solvent, the molecular weight of products therefrom is 50,000, contains 3%(w/w) unreacted alcohol.

Additive 4

2-N, the dialkyl ammonium salt of N dialkyl amide yl benzoic acid, it is 1 mole Tetra hydro Phthalic anhydride to be mixed with two (hydrogenated tallow) amine of 2 moles to form under 60 ℃.

The result is as follows:

Example 1

-

Fuel characteristic

Cloud point-14 ℃

Temperature-18.6 ℃ appears in wax

178 ℃ of initial boiling points

20%????230℃

90%????318℃

355 ℃ of full boiling points

-25 ℃ of following wax content 1.1%(weight)

Additive 1,2 and 3 is respectively sneaked in the fuel with 250ppm, and test temperature is-25 ℃.The length of finding wax crystalls is 1200 millimicrons, and the wax by Cummins FF105 purolator is in 90(weight) more than the %.

In this test, fall, only increased 2.2KPa, further confirmed passing through of wax by the pressure of observing purolator.

Example 2

-

Repeat example 1, find that wax crystalls length is 1300 millimicrons, it is 3.4KPa that maximum value falls in the resulting pressure of purolator.

Example 3

-

Fuel characteristic

0 ℃ of cloud point

Temperature-2.5 ℃ appears in wax

182 ℃ of initial boiling points

20%????220℃

90%????354℃

385 ℃ of full boiling points

Wax content 1.6%(weight under the test temperature)

Additive 1,2 and 3 is respectively used 250ppm, finds that wax crystalls length is 1500 millimicrons, and about 75% wax passes through Bosch 145434106 purolators under-85 ℃ test temperature.The peak pressure of purolator is reduced to 6.5KPa.

Example 4

-

Repeating example 3, find that wax crystalls length is 2000 millimicrons, 50(weight is arranged approximately) wax of % passes through, and peak pressure is reduced to 35.3KPa.

Example 5

-

With used fuel in the mixture process example 3 of the additive 1 of 400ppm and 100ppm additive 2, test under-8 ℃ by example 3, wax content is a 1.4(weight under this temperature) %.Find that wax crystalls length is 2500 millimicrons, 50(weight) wax of % passed through purolator, and maximum resulting pressure is reduced to 67.1KPa.

Comparison example 6

-

With used fuel in the mixture process example 3 of 4 parts of additives 4 of 500ppm and 1 part of additive 2, under-8 ℃, test, find that wax crystalls length is 6300 millimicrons, 13(weight) wax of % passed through purolator.

This example is one of extraordinary example in the prior art, does not wherein have crystal and passes through.

The scanning electron photo of the wax crystalls that forms in the fuel of example 1～6 is shown in Fig. 1～6.

Therefore, example 1～4 expression, if crystal can pass through purolator reliably, best cold warm nature can expand to this feasible so far higher wax content, same, when temperature was lower, the wax appearance point can be extended to the higher fuel of wax content.This and fuel system are irrelevant, for example with the engine heating from the circulation ability of the charging fuel of fuel tank sucking-off, dyestuff, charging fuel ratio, main fuel filter surface-area and the ratio of fuel stream and the size and the position of preceding purolator and screen cloth with circulating fuel.

Example 1～3 expression crystal length is less than about 1800 millimicrons purolator test, the consequently non-perseverance of the characteristic of fuel.

Example 7

-

In this example, in distillate fuel, add additive 1 with following properties:

IBP????180℃

20%????223℃

90%????336℃

FBP????365℃

Temperature (WAT)-5.5 ℃ appears in wax

Cloud point-3.5 ℃

For the purpose of contrast, also in distillate fuel, add following additive:

Additive A

-

The mixture of ethylene, one of them is an additive 2(1 weight part), another kind of (3 weight part) has content is 36(weight) vinyl-acetic ester of %, molecular weight (Mn) is 2000, and degree of branching is that per 100 methylene radical have 2～3 methyl (measuring with 500MHzNMR).

Additive B

-

Additive 4 and 2 mixture, its mol ratio is 4: 1.

Addition of C

-

Molecular-weight average is the mixture of 600 polyoxyethylene glycol two sweet potato acid esters.

Additive D

-

Ethylene/propene copolymer, therein ethylene content are 56(weight) %, molecular-weight average is 60,000.

Express the additive capacity of adding down, and test, be described in detail as follows by PCT:

Programming cool test (PCT)

The design of this slow refrigeration test relates to the warming oil of storage.The cold flow properties that contains additive fuel is measured with PCT, and its method is as follows: 300ml fuel is cooled to test temperature with 1 ℃/hour speed linearity, keeps constant then.After this test temperature was through 2 hours, remove the about 20ml of scalping with suction pipe, to prevent to test the influence that is subjected to unusual big wax crystalline substance, this wax crystalline substance has the trend that forms on oil/air interface when cooling.Relax and stir, the wax in the bottle is disperseed, add CFPPT ^*Filtration unit.The tap of fetching boiling water applies the vacuum of 500mm mercury column, when the fuel of 200ml has entered the scale receiving vessel by purolator, closes water tap.If collected 200ml by given sieve mesh in 10 seconds, then record " qualified " if flow velocity is too slow, shows that purolator stops up, then record " defective ".

Be recorded in the screen size that passes through under the test temperature.

* the cold purolator of CFPPT-stops up experimental tests Cold Filter Plugging Point Test) be described in detail in " Journal of the Institute of Petroleum ", Vol.52, № 510, and June 1966, pp.173～185.

Table

-

The thinnest PCT sieve mesh that additive (mol ratio) passes through under-11 ℃

150ppm 250ppm(active ingredient)

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

As can be seen, when only using a kind of additive, optimum is obtained by additive 1, and when using a pair of additive, optimum obtains during for one of them when additive 1.

Example 8

-

The fuel of Shi Yonging has following properties in this example:

（ASTM-D86）

IBP????190℃

20%????246℃

90%????346℃

FBP????374℃

Temperature (WAT)-1.5 ℃ appears in wax

Cloud point+2.0 ℃

Following additive active ingredient with 1000ppm is handled above-mentioned fuel:

(E) additive 2(1 weight part) and additive 4(9 weight part) mixture.

(F) commercially available ethylene additive, it is sold with ECA5920 by Exxon Chemicals company.

(G) by 3,1 part of additive D of 1,1 part of additive of 1 part of additive and 1 part of mixture that additive K forms.

(H) the ethylene additive of selling with 2042E by Amoco company.

(I) the ethylene/propylene vinyl acetate copolymer additives of selling with Keroflux5486 by BASF.

(J) additive-free

(K) reaction product of the pyromellitic anhydride of 4 moles two (hydrogenated tallow) amine and 1 mole, this reaction is at 150 ℃, stirs to finish in 6 hours under the nitrogen protection.

Measure the following performance of these fuel then:

(ⅰ) in the ability of-9 ℃ of following fuel by the diesel engine main fuel filter, and the percentage ratio that passes through the wax of filter, the result is as follows:

Additive wax break period pass through percentage ratio

E 11 minutes 18～30%

F 16 minutes 30%

G does not have interruption 90～100%

H 15 minutes 25%

I 12 minutes 25%

J 9 minutes 10%

(ⅱ) pressure of main fuel filter falls and time relation, and it the results are shown among Fig. 7.

(ⅲ) by cool off the precipitation of measuring wax in the oil in a dial drum, used graduated cylinder contains the 100ml scale, and its top line is equivalent to 100% of fuel height.Will this tube from (best) be higher than this fuel 10 ℃ of cloud points but not more than the low fuel cloud point 5 ℃ temperature be cooled to test temperature with 1 ℃/hour.Then it is placed specific time.Test temperature and soaking time depend on application, i.e. diesel engine fuel and warming oil.Test temperature generally is lower than 5 ℃ of its cloud points at least, and minimum cold soaking time was at least 4 hours under this test temperature.Preferably this test temperature should be lower than 10 ℃ of valenta values or more, and soaking time should be 24 hours or longer.

Soaking time is observed this graduated cylinder after finishing, and estimates the sedimentary degree of wax crystalls, promptly exceeds the height of any wax layer in a bottom surface (0ml), and represents with the percent value of cumulative volume (100ml).Can see limpid fuel on sedimentary wax crystalls, this mensuration form is enough to usually as the sedimentary determination methods of wax.Usually the oil on the wax crystalls layer of visible precipitate is muddy, or visible wax crystalls is closeer when its approaching end.In this case, can use a kind of more quantitative analytical procedure, with its top 5%(5ml) the careful sucking-off of fuel and it is stored, discard to sucking-off 45% from last then, afterwards again sucking-off 5% with its storage, and then sucking-off 35% discards, and 10% last heating makes the brilliant dissolving of wax, collects.After, these are stored samples respectively as the sample of top layer, middle level and bottom.Importantly the vacuum tightness of Cai Yonging is quite low, i.e. 200mm water column, and the top of suction pipe just should be placed on the surface of fuel, in order to avoid cause liquid-flow, this flowing will be upset the wax concentration at different layers place in the graduated cylinder.Then, these samples were heated 15 minutes down at 60 ℃,, measure with differential scanning formula calorimetry (DSC).

The DSC technology comprises uses a kind of machine, as Du Pont's 9900 series or Mettler TA2000B.Use a kind of machine in back at this.The sample of 25 μ l is put in the sample pool, common kerosene is put in the contrast pond, then they are cooled to be higher than at least the temperature that 10 ℃ of temperature (WAT) (being preferably 20 ℃) appears in wax with 22 ℃/minute speed from 60 ℃, and then they are cooled to be less than about its WAT20 ℃ temperature with 2 ℃/minute speed.Simultaneous test must be do not precipitate, uncooled processing fuel.Set up the relation of wax precipitation degree and WAT then.(or the original WAT of the WAT-of WAT=working sample) negative value is represented to pass through the enrichment of precipitation wax by the dewaxing of precipitation fuel on the occasion of expression.The content of wax also can be used as the precipitation yardstick of these samples.This available %WAT or △ %WAX are illustrated (the %WAX one original %WAX of △ %WAX=deposit sample) and emphasize once again; Negative value is represented the dewaxing by precipitation fuel, on the occasion of the enrichment of expression by precipitation wax.The DSC area under a curve obtained when these wax contents were reduced to specified temp by measurement.

This wax is cooled to-9 ℃ with 1 ℃/hour speed from+10 ℃, and before test all cold 48 hours.The result is as follows:

Additive range estimation wax precipitation WAT (℃) data

5% bottom 10%, 5% middle part, top

The all muddy bottom closeer-10.80-4.00-3.15 of E

F top 50% transparent-13.35-0.80-0.40

G????100%????-7.85????-7.40????-7.50

H top 35% transparent-13.05-8.50+0.50

I top 65% is transparent

J 100% semi-gelled-6.20-6.25-6.40

(these results also are shown among Fig. 8)

Original WAT WAT (℃) (sedimentary sample)

5% bottom 10%, 5% middle part, (unprecipitated fuel) top

E????-6.00

F????-5.15????-4.80????+2.00????+2.85

G????-7.75????-8.20????+4.35????+4.75

H????-5.00????-0.10????+0.35????+0.25

J????-6.20????-8.05????-0.35????+4.50

0.00????-0.05????-0.20

(annotate: can obtain the remarkable reduction of WAT by effective additives (G).）

The %WAX(deposit sample)

5% bottom 10%, 5% middle part, top

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

(annotate: %WAX measures from the area measurement of WAT to-25 ℃ by prolonging initial baseline, demarcates with the crystalline wax of known quantity in advance)

The result shows that when the existence owing to additive reduced crystallographic dimension, the precipitated phase of wax crystalls was when rapid.For example, untreated fuel when being cooled to be lower than their cloud point temperatures, tends to express wax crystalls precipitation in a small amount, because tabular crystal interlinks, can not freely in liquid, fall, and form gel-like structure, but when adding flow improver additive, crystal may be enhanced, so it is less and tend to form the needle-like of size in 10 micron number magnitudes that their form becomes sheet, this crystal can free movement in liquid, and precipitated phase is when fast.This wax crystalls precipitation can give rise to trouble in bin and Vehicular system.Spissated wax layer can be sucked out suddenly, when particularly low or fuel tank is shaken when level of fuel (for example, Ackermann steer angle), purolator may take place stop up.

If the wax crystalls size further can be reduced to below 10000 millimicrons, the crystal sedimentation is quite slow, compares with the situation that contains the fuel that precipitates wax crystalls, and the anti-sedimentation of wax can be given fuel with advantageous property.Be lower than about 4000 millimicrons if the wax crystalls size can be reduced to, during fuel storage in, crystalline precipitation trend is almost eliminated.Require size if crystalline size is reduced to our the best, in required several weeks, this wax crystalls will keep suspended state in fuel at some stocking system, thus, can eliminate the problems referred to above effectively.

(ⅳ) the CFPP performance is as follows:

Addition of C FPP temperature CFPP reduces

E????-14????11

F????-20????17

G????-20????17

H????-20????17

I????-19????16

J????-3????-

(ⅴ) average crystalline size is as follows:

Additive size (millimicron)

E????4400

F????10400

G????2600

H????10800

I????8400

J thin slice about 50000

Claims (5)

1, boiling point is 120～500 ℃ a distillate fuel oil, and it is being lower than under the temperature that 10 ℃ of temperature appear in wax, its wax content at least 0.3 (weight) %, and the mean particle size of the wax crystalls under this temperature is less than 4000 millimicrons.

2, distillate fuel as claimed in claim 1, the mean particle size of wax crystalls wherein is less than 3000 millimicrons.

3, distillate fuel as claimed in claim 1, the mean particle size of wax crystalls wherein is less than 2000 millimicrons.

4, distillate fuel as claimed in claim 1, the mean particle size of wax crystalls wherein is less than 1500 millimicrons.

5, distillate fuel as claimed in claim 1, the mean particle size of wax crystalls wherein is less than 1000 millimicrons.

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