US3008813A

US3008813A - Hydrocarbon oils having improved water tolerance

Info

Publication number: US3008813A
Application number: US770520A
Authority: US
Inventors: Joel R Siegel
Original assignee: Exxon Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1958-10-29
Filing date: 1958-10-29
Publication date: 1961-11-14
Anticipated expiration: 1978-11-14

Description

Nov. 14, 1961 J. R. SIEGEL 3,008,813

HYDROCARBON OILS HAVING IMPROVED WATER TOLERANCE Filed Oct. 29, 1958 EFFECT OF DICOCO DIMETHYL AMMONIUM CHLORIDE UPON HAZE SETTLING RATE 25 I I I CONTAINING N0 DICOCO DIMETHYL l AMMONIUM CHLORIDE /.HAzE

l0 on. CONTAINING 0.0005 WT.%

0|c0c0 DIMETHYL AMMONIUM CHLORIDE O l I l I l I I0 '30 40 so HOURS SETTLING doel R. Siege! Inventor By gm a, Li Ahorney United States Patent Filed Oct. 29, 1958, Ser- No. 770,520 12 Claims. (CI. 4462) The present invention relates to improvements in the water tolerance of hydrocarbon oils and more particularly relates to petroleum distillate fuels and similar hydrocarbon oil products having incorporated therein additive agents singularly adapted to prevent the formation of persistent haze and stable emulsions when such products are contacted with water during handling and storage.

Ashless oil-soluble polymeric dispersants have largely displaced metal sulfonates, metal naphthenates and similar compounds for use as stabilizing additives in petroleum distillate fuels and related hydrocarbon oil products because of their increased ability to suspend insoluble degradation products formed in such oils. Sludge and sediment which might otherwise tend to clog fuel lines, orifices, screens and filters through which the oils must pass are held in suspension to a much greater extent by the polymeric additives than by the additive materials formerly employed. These increased dispersive properties, although highly desirable from the standpoint of oil stability, have given rise to water tolerance problems much more serious than those heretofore encountered. The polymeric materials employed as oil stabilizing addi-tives exhibited particularly pronounced tendencies to suspend any water with which the oils come into contact and hence extremely persistent haze and stable emulsions are formed upon contact of oils containing the polymeric additives with water. Since an aqueous phase exists in most tanks and other vessels containing such oils, haze formation and emulsification are almost impossible to avoid. As a consequence, the marketability of distillate fuels, lubricating oils, transformer oils, turbine oils and other petroleum distillate products in which polymeric dispersants are used is often seriously affected.

The present invention provides a class of new and improved additives which are surprisingly effective for increasing the water tolerance of petroleum distillate fuels and similar liquid hydrocarbon oils containing polymeric dispersant additives. In accordance with the invention, it has now been discovered that the addition of minor amounts of certain quaternary ammonium compounds to such oils greatly reduces the persistence of haze and emulsions formed when the products are contacted with water and thus permits their transportation and storage in the presence of an aqueous phase without adverse results.

The quaternary ammonium compounds which have been found to be singularly effective for improving the water tolerance of petroleum products in accordance with the invention are dialkyl dimethyl ammonium chlorides having alkyl groups which each contain from 12 to 14 carbon atoms. It has been found that compounds of this type are critical for purposes of the invention. Closely related tetraalkyl ammonium chlorides such as the trialkyl monomethyl ammonium chlorides and the monoalkyl trimethyl ammonium chloride are not effective for reducing haze and emulsion formation, are readily extracted by water, adversely affect the action of the polymeric stabilizing additives, or are otherwise unsuitable for purposes of the invention. Specific examples of dialkyl dimethyl ammonium chlorides which may be employed are didodecyl dimethyl ammonium chloride, ditridecyl dimethyl ammonium chloride, dodecyl tridecyl dimethyl ammonium chloride, dodecyl tetradecyl dimethyl ammonium chloride and tridecyl tetradecyl dimethyl ammonium chloride. Also useful for purposes of the invention are dialkyl dimethyl ammonium chlorides derived from naturally occurring materials such as coconut oil which contain at least 50% by weight of C to C alkyl groups. Dicocodimethyl ammonium chloride, derived from coconut oil, contains from about 55 to about 70% of C to C alkyl groups and has been found eminently satisfactory for purposes of the invention. The alkyl groups outside the C to C range in these mixed dialkyl dimethyl ammonium chlorides apparently do not contribute to the improved water tolerance of the products to which the chlorides are added but appear to have no adverse effect. Such mixed dialkyl dimethyl ammonium chlorides are generally referred to as technical dilau'ryl dimethyl ammonium chlorides and are readily available from corrnnercial sources. Such mixtures are therefore preferred for purposes of the invention.

The polymeric dispersant additives primarily responsible for the poor water tolerance of distillate fuels and similar products are widely used commercially and are well known to those skilled in the art. These dispersants in general are polymers and copolymers of unsaturated organic esters, nitriles and similar monomers containing vinyl, vinylene or vinylidene linkages. The dialkyl dimethyl ammonium chlorides employed in accordance with the invention have been found effective when used in oils containing a wide variety of such polymeric dispersants.

A class of polymeric dispersant additives in conjunction with which the dialkyl dimethyl ammonium chlorides have been found to be particularly effective are those which are prepared by the copolymerization of an alkyl chloropropyleneoxy mixed ester of an unsaturated conjugated dibasic acid with a polymerizable organic monomer containing a vinyl linkage. The alkyl chloropropyleneoxy mixed esters used as one of the components of such copolymers are prepared by'first reacting a C to C unsaturated conjugated dibasic acid such as maleic acid, fumaric acid, citraconic acid, mesaconic acid or a mixture of such acids or their anhydrides,,when they exist, with a long chain saturated aliphatic alcohol to produce a half ester. Suitable-alcohols for this purpose are those containing from about 8 to about 24 carbonatoms per molecule, preferably about 8 to 18 carbon atoms per molecule. Straight chain primary alcohols such as dodecyl, cetyl, eicosyl and docosyl alcohols are preferred but branched chain alcohols such as 2-ethy1hexanol-1 and C oxo-alcohols, secondary alcohols such as caprylalcohol and mixtures of straight and branched-chain alcohols may also be used. Commercially marketed mixtures of alcohols of the requisite chain length, such as those obtained by the hydrogenation of coconut oil may also be used.

.may range from about 1:1 to 1:4. Addition of the epichlorohydrin takes place throughthe epoxy group and the chlorine atom is unaffected. The mixed ester may thus contain from 1 to about 3 chlorine atoms.

The mixed ester prepared as described above is then copolymerized with from about /2 to about 2-0 parts of an unsaturated organic monomer containing a vinylfg'roup in the presence of gamma radiation, a peroxide type catalyst such as benzoyl peroxide, or an azo catalyst such as alpha-alpha azo-bis-isobutyronitrile. Suitable mono mers containing vinyl groups include hydrocarbons such as styrene, isobutylene and butadiene'; esters such as vinyl propionate and methyl methacrylate; ethers such as divinyl ether; and nitriles such as acrylonitrile and vinylacetonitrile. Mixtures of such monomers containing materials.

' forrnates,

vinyl groups with other copolymerizable materials, long chain alcohol esters of unsaturated conjugated dibasic acids such as lauryl maleate and tallow fumarate for example, may also be used. Vinyl esters of short chain fatty acids, particularly vinyl acetate and mixtures of such esters with fumarate or malea-te esters of long chain aliphatic alcohols containing from about 8 to about 20 carbon atoms per molecule are preferred monomers for preparation of the copolymers with the mixed esters.

The resulting copolymers are oil-soluble and preferably have molecular Weights between about 6000 and about 20,000 Staudinger. Such copolymers are described in copending application S.N. 673,156, filed July 22, 1957.

A second class of polymeric dispersant additives with which the dialkyl dimethyl ammonium chlorides are es pecially effective are oil-soluble, nitrogen-containing addition type copolymers prepared by copolymerizing an amine-free monomer containing one polymerizable ethylenic linkage and an aliphatic hydrocarbon chain of from 8 to 18 carbon atoms with a monomer containing a nitrogen atom and one polymerizable ethylenic link-age. Such copolymers may be prepared, for example, by the copolymerization of an acrylic or alpha-substituted acrylic ester of an aliphatic alcohol containing an average of from 8 to 18 carbon atoms, such as lauryl methacrylate, with an ethylenically unsaturated compound containing a basic amino group, such as beta dimethylamino-ethyl methacrylate. Other specific examples of the amine-free monomers containing a polymerizable ethylenic linkage and a C -C aliphatic chain include the tridecyl, cetyl and octadecyl esters of acrylic and methacrylic acids. Also suitable are esters of these acids prepared from mixtures of alcohols such as those containing primary alcohols of from 10 to 18 carbon atoms derived by the hydrogenation of coconut oil and sold under the trade name Lorol. A typical mixture consists chiefly of lauryl alcohol having 12 carbon atoms per molecule and has the following approximate composition:

Alcohol constituent- Weight percen c rr orr 4.0 C12H25OH 55.5 c rr orr 22.5 c n ou 14.0 c rr orr 4.0

in addition to those described above may be incorporated into the copolymers of the second preferred class as filler Such filler materials include vinyl and allyl acetates, propionates; isobutylene; styrene; methyl meth-acrylate; ethyl vinyl ether and the like. The final copolymer may contain from about 20% to about 99% of the nitrogen-free monomer, from about 0.5% to 50% of the nitrogen-containing monomer, and from about 0 to about 79% of the monomer used as a filler material. Many of the polymeric additives falling within the second preferred class described above are de scribed in detail in US. Patent No. 2,737,452, issued March 6, 1956.

Polymeric dispersant additives of the second class described above are sometimes employed in combination with tertiary alkyl primary amine-s. Although such amines do not have pronounced dispersant properties,

they effect a considerable improvement in the stabilizing action of the nitrogen-containing polymeric dispersants. They do not, however, overcome the tendency of such dispersants to suspend water in oils in which they are present and hence do not prevent the water tolerance problem caused by the dispersanrts. The dialkyl dimethyl ammonium chlorides may therefore be employed to advantage in oils containing both a polymeric dispersant and a tertiary alkyl primary amine.

The tertiary alkyl primary amines useful with the polymeric dispersants described above in general are those having two alkyl groups of from 1 to 3 carbon atoms attached to the tertiary carbon atom and one alkyl group of from 5 to 21 carbon atoms attached to the tertiary carbon atom. Tertiary alkyl primary amines containing a total of from 8 to 18 carbon atoms per molecule are preferred. Particularly preferred are C tertiary alkyl primary amines. Mixtures of such amines such as those derived from polyolefins may also be used.

Tertiary alkyl primary amines such as those described above are generally employed in combination with the nitrogen-containing polymeric dispersants in concentrations such that the ratio of amine to dispersant in the oil ranges from about 2 to 1 to about 18 to 1. Amine concentrations between about 0.003 wt. percent to about 0.8 wt. percent are especially effective.

Many other polymeric dispersant additives suitable for the stabilization of hydrocarbon oils will be familiar to those skilled in the art. The stabilization of haze and emulsions is a universal property of such disperant additives and the dialkyl dimethyl ammonium chlorides may be employedwith a wide variety of such materials. Representative examples of other ashless, oil-soluble polymeric stabilizing additives are described in US. Patent 2,737,496 to Catlin; in US. 2,800,452 to Bondi et al.; and in application SN. 690,184, filed October 15, 1957, now US. Patent 2,958,590.

The oils in which the additives of the invention may be incorporated are liquid petroleum distillate products boiling in the range between about 75 .and about 900 F. Such products include gasolines, aviation turbo-jet fuels, kerosenes, diesel fuels, transformer oils, turbine oils, heating oils, and lubricating oils. The additives are particularly effective in distillate fuels boiling in the range between about 250 F. and about 750 F. Such fuels include turbo-jet engine fuels, diesel fuels and heating oils which have particularly poor stability properties and require the use of relatively large amounts of the polymeric dispersant additives. Aviation turbo-jet engine fuels are defined by US. Military Specifications MIL- F 5624C, MIL F-25524A, and MIL F 2258A and are generally referred to as IP4, JP-5 and IP-6.

. 'Diesel fuels in connection with which the additives of the invention are particularly useful are more fully dedescribed in ASTM Specification D-97553T and may be used in stationary, marine and automotive type engines. Typical of the heating oils in which the additives may be employed are those described in ASTM Specification D396-48T, particularly those in grades 1 and 2 thereof.

The polymeric dispersant additives are generally employed in petroleum hydrocarbon products such as those described above in concentrations ranging from about 0.001% and about 1% by weight. Concentrations of from 0.001% to 0.05% are generally preferred. The dialkyl dimethyl ammonium chlorides which are used in such oils may be incorporated therein in concentrations in the range of from about 000025 wt. percent to about 0.0 1 wt. percent. Chloride concentrations in the range of from about 0.0005 wt. percent to about 0.001 wt. percent have been found to be generally effective and are preferred, since it has been found that the stabilizing properties of some dispersant additives may suffer when the dialkyl dimethyl ammonium chlorides are present in very high concentrations.

-measuring the volume of the emulsion phase.

' lows:

The ammonium chloride compound may be incorpor-ated into the fuels by dissolving them in a suit-able solvent such as 'isopropanol, butanol, benzene or the like and then adding the resultant solution to the oil in quantities sufiicient to give the desired additive concentrations. If desired, additive concentrates containing both the polymeric dispersant stabilizing additive and the dialkyl dimethyl ammonium chloride compound in a suitable solvent may be prepared. Other additive materials commonly used in the products to which the concentrate is to be added may also be included in such concentrates. Such other additive materials may comprise rust inhibitors, anti-static additives, corrosion inhibitors, dyes, dye stabilizers and the like. i

The invention may be further illustrated by the following examples and the accompanying drawing.

EXAMPLE 1 Samples of a petroleum distillate heating oil which had been stabilized by the inclusion therein of 0.01% by weight of various polymeric dispersant additives were tested to determine the persistence of the haze formed when the fuel was contacted with water and the stability of the emulsions formed during such contacting. The fuel employed was .a blend consisting of about 50% by volume of virgin gas oil and about 50% by volume of catalytically cracked stock. Typical inspections for a fuel of this type are as follows:

Conradson carbon residue, wt. percent 0.006

The persistence of the haze formed in this oil upon contact with water was measured in Waring Blendor haze tests wherein five milliliters of water and 500 milliliters of the oil were mixed in a Waring Blendor for a period of five minutes, the oil-Water mixture was then allowed to stand for six hours, and the amount of light which was transmitted through the oil under standardized conditions was measured. :The light transmission was expressed as a percentage of the total light emitted from the source. This test has been found to be an extremely effective means for determining the degree to which haze is present in hydrocarbon oils and is recognized as reliable throughout the petroleum industry.

Herschel emulsion tests were carried out to determine the effect of the additives upon emulsification by stirring 40 millilters of oil and 40 milliliters of water for five minutes at a temperature of 77 F. to form an emulsion, letting the mixture stand for 15 minutes, and then Similar tests are widely used'for determining the emulsification tendencies of turbine oils in accordance with ASTM Standard D-1401-56T and in similar applications.

Three different tetraalkyl ammonium chlorides were added in concentrations of 0.0008 wt. percent to separate samples of the same heating oil containing 0.01 wt. percent of the same polymeric dispersant additive. The tetraalkyl ammonium chlorides employed were as fol- (1) Dicoco dimethyl ammonium chloride-a dialkyl dimethyl ammonium chloride having mixed alkyl groups derived-from coconut oil as follows: 8% C radicals, 7% C radicals, 48% C radicals, 18.5% C radicals, 8% C radioalsand 10.5% C radicals.

" (2) Disoya dimethyl ammonium chloride-a dialkyl dimethyl ammonium chloride having mixed alkyl groups derived from soybean oil which include about 8% C radicals, about 88% C radicals and about 4% C radicals.

(3) Dihydrogenated tallow dimethyl ammonium chloride-a dialkyl dimethyl ammonium chloride having mixed C and C alkyl groups derived from hydrogenated tallow.

I (4) Tallow trimethyl ammonium chloride- -a monoalkyl trimethyl ammonium chloride having mixed C and C alkyl groups derived from tallow.

The oil samples containing the polymeric dispersant additive and the above tetraalkyl ammonium chlorides were than subjected to Waring Blendor haze tests and Herschel emulsion tests, both with and without prior water extraction. About 1% water was used in the water extraction step. The results obtained in these tests are in Table I.

Table I EFFECT OF TETRAALKYL AMMONIUM GHLORIDES UPON HAZE AND EMULSIFICATION IN HEATING OILS Waring Blendor Herschel emulsion haze test, percent test, milliliters light transmission emulsion after 15 after 6 hours minutes Fuel Fuel not Fuel ex- Fuel not Fuel exwater extreated water extracted tracted with tracted with water water Base heating oil 94 0 0 Base heating oil+0.01% additive A 1 14 12 4 31 Base heating oil+0.01% additive A+0.0008% dicoco dimethyl ammonium chlori e 95 81 l 2 Base heating 0i1+0.01% additive A+0.0008% disoya dimethyl ammonium chloride 54 30 3 18 Base heating oil+0.01% additive A+0.0008% dihydro- I genated tallow dimethyl ammonium chloride 53 12 18 15 Base heating oi1+0.01% additive A+0.0008% tallow trimethyl ammonium chloride 90 6 Base heating oil+0.01% additive B 2 48 64 Base heating 0il+0.01% additive B+0.0008% dicoco dimethyl ammonium chloride 92 88 Base heating oil+0.01% additive B+0.0008% disoya dimethyl ammonium chlo- I ride 36 60 Base heating oi1+0.01% additive B|-0.0008% dihydrogenated tallow dimethyl ammonium chloride 29 27 Additive A was a copolymer of 1 mol of vinyl acetate, 0.25 mol of isooctyl chloropropyleneoxy maleate, and 0.75 mol of mixed 0 5-0 alkyl iumarates, 50 weight percent concentration in benzene.

2 Additive B was a mixture of 8 parts of a C1 tertiary alkyl primary amine and 1 part of a copolymer prepared from 8 parts of Lorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate.

From the Waring Blendor test results in the above table it can be seen that the light transmission through the base heating oil containing the polymeric dispersant additive was quite low, indicating a high haze level. The fact that this haze persisted even though six hours had elapsed between the time the water and oil were mixed and the time the light transmission values were determined shows that it was exceptionally stable due to the presence of the polymeric dispersant in the oil. The results obtained with the samples containing the dicoco dimethyl ammonium chloride demonstrate the remarkable effectiveness of this additive for preventing the formation of persistent haze in oils. This effectiveness is particularly outstanding in view of the fact that this material is marketed commercially for use as a general emulsion stabilizer and might therefore be expected to promote,

rather than hinder, the formation of persistent haze. The disoya dimethyl ammonium chloride and the dihydrogenated tallow ammonium chloride, both of which have structures very similar to that of dicoco dimethyl ammonium chloride but do not contain predominantly C and C alkyl groups, were much less efiective. I Results of the Herschel emulsion tests confirm these findings. The above data also demonstrate that the eifectiveness of dicoco dimethyl ammonium chloride is not seriously raffected by water extraction. The disoya dimethyl =ammonium chloride and the dihydrogenated tallow ammonium chloride, on the other hand, were much less effective after water extraction.

The data obtained with tallow trimethyl ammonium chloride demonstrate that a satisfactory additive must not be extracted by water to any significant extent. The tallow trimethyl ammonium chloride was largely removed from the fuel during the extraction step and hence afforded little protection against the formation of persistent haze when the fuel was subsequently subjected to the Waring Blendor test. The dicoco dimethyl ammonium chloride, on the other hand, was extracted only to a slight degree and was nearly as effective following the water extraction step as it was prior to water extraction. Since distillate fuels and other petroleum products in which polymeric dispersant additives are frequently employed are often contacted with relatively large quantities of water under conditions which may lead to the extraction of additives contained therein, this difference between the dicoco dimethyl ammonium chloride and the tallow trimethyl ammonium chloride is a significant one.

EXAMPLE 2 In order to determine the effectiveness of commercial demulsifiers for use in oils containing polymeric dispersant additives, tests similar to those described above were carried out upon samples of heating oils containing such inhibitors. The heating oils employed had properties similar to those of the oil used in the preceding example and contained polymeric dispcrsants in 0.01 wt. percent concentrations. The samples were first subjected to Waring Blender haze tests. If the results from this test indicated that the particular inhibitor showed promise, Herschel emulsion tests were carried out. The overall results obtained are summarized as follows.

Table II NorE.For footnotes 1 and 2 see Table I.

Tests were carried out on 70 other commercial demulsifiers by adding 0.005 wt. percent of the material to be tested to 250 ml. of heating oil containing 0.01 wt. percent of polymeric dispersant B, shaking the Sample with 1% 'Water, and

then usually observing rate at which the haze cleared. Sixty-three of these commercial additives were found to promote haze in the presence of the polymeric dispersant, six had no visible influence upon the hazing properties of the oil containing the dispersant, and one indicated a slight improvement in haze clearing rate. When this latter additive was retested, the results could not be duplicated.

EXAMPLE 3 Tests were carried out to determine the eifect of dicoco dimethyl ammonium chloride upon the stability of distillate petroleum products. The test employed was the accelerated storage stability test describedin detail in New Fast Test Method for Distillate Storage Stability, by W. A. Konrad, N. L. Shipley and T. S. Tutwiler on page of Petroleum Processing for September 1946. Briefly, the accelerated filter plugging test consists of heating a sample of the oil to be tested at a controlled rate for L6 hours to a final temperature of 230 F. in order to accelerate the formation of sediment in the oil. The oil sample is then cooled and passed through a felt filter pad at a constant rate of 1 gallon per hour. As sediment accumulates on the filter under constant oil flow conditions, the pressure drop across the filter increases. After 12 liters, the Standard Volume used in the test, has been filtered, a record is made of final pressure drop across the filter, the weight of sediment collected is determined, and the appearance of the filter is noted. These criteria are individually interpreted on a demerit basis wherein 0 is an excellent rating and 10 is a very bad rating. The values for the 3 criteria, final pressure drop, Weight of sediment and appearance, are averaged arithmetically to obtain the overall accelerated filter plugging test demerit value for the oil. Results obtained in this test are reproducible to :03.

The oil employed in the accelerated filter plugging tests was a heating oil having properties substantially the same as those of the oil described in Example 1. Tests were also made on samples of this oil containing the polymeric dispersant additives described in Examples 1 and 2 and upon samples containing both the polymeric dispersant additives and dicoco dimethyl ammonium chloride. Table III.

Table III EFFECT OF DICOCO DIMETHYL AMMONIUM CHLORIDE ON FUEL STABILITY Accelerated Fuel filter plugging test overall demerit Base heating oil 9. 3 Base heating oil+0.01% polymeric dispersant A 1 l 0 Base heating oil+0.0l% polymeric dispersant A 0.0005% dicoco dimethyl ammonium chloride- 0. 7 Base heating oil+0.01% polymeric dispersant A 0.001% dicoco dimethyl ammonium chloride 1.3 Base heating oil+0.01% polymeric dispersant B 1 1.0 Base heating oil+0.0l% polymeric dispersant B 0.001% dicoco dimethyl ammonium chloride 1 0 1 Polymeric dispersant A was a copolymer of 1 mol. of vinyl acetate, 0.25 mols. of isooctyl ohloropropyleneoxy maleate, and 0.75 mols. of mixed ole-O13 alkyl iumarate. 50% concentration in benzene.

2 Polymeric dispersant B was a mixture of 8 parts of a Cu tertiary alkyl primary amine and 1 part of a copolymer prepared from 8 parts of Lorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate.

Fro-m the foregoing table it is evident that the addition of dicoco dimethyl ammonium chloride to petroleum distillate fuels and products containing polymeric dispersant additives does not adversely eifect the stability of such fuels or interfere with the stabilizing action of the polymeric additives. At the concentrations in which they are used, the ammonium chloride compounds reduce the ability of the dispersants to suspend water but do not reduce their ability to suspend insoluble reaction products formed in the oil. The data in Table III sug- The results of these tests are set forth in gest that in some instances it may be preferred to limit the amount of dicoco dimethyl ammonium chloride added to oils containing polymeric dispersant stabilizing additives to about 0.001 wt. percent or less. The demerit rating of the sample containing 0.01% of dispersant A and 0.0005% of the chloride was slightly better than that of the sample containing the same amount of the polymeric dispersant and 0.001% of the chloride. The data are consistent within the reproducibility of the test.

EXAMPLE 4 Table IV EFFECT OF EXTRACTION WITH PIPELINE INHIBITOR UPON TETRAALKYL AMMONIUM CHLORIDE HAZE PREVENTIVE Percent light transmission after 6 hrs. Fuel following extraction with pipeline inhibitor solution 1 Base fuel+0.01% polymeric dispersant B 2 51 Base fuel-{001% polymeric dispersant B +0.00076% dicoco dimethyl ammonium chloride Base fuel+0.0l% polymeric dispersant B +0.00068% dicoco dimethyl ammonium chloride 90 Base fuel+0.01% polymeric dispersant B +0 00060% dicoco dimethyl ammonium chloride 84 Base iuel+0.01% polymeric dispersant B +0 005% dicoco dimethyl ammonium chloride 96 The inhibitor was an aqueous solution used commercially for preventing pipeline corrosion and consists of 720 gms. of NBNO: and 8.6 gms. of N aOH in 2,000 ml. of distilled water.

1 See footnote 2, Table III.

The above data demonstrate that the aqueous pipeline inhibitor solution did not extract the dicoco dimethyl ammonium chloride from the fuel to an appreciable extent and hence did not increase the tendency of the fuel to form persistent haze when subsequently contacted with water. The results shown above also show the effect of varying the concentration of the dicoco dimethyl ammonium chloride and indicate that the additive is particularly eifective at concentrations of about 0.0005 wt. percent.

EXAMPLE 5 the oil in the Waring Blendor. The results of these tests are summarized in Table V and it can be seen that the addition of the chloride after haze formation had no effect whatsoever.

a Base heating 0il+0.005% polymeric dispersant 13 I Table V EFFECT OF ADDITION OF DICOOO DIMETHYL fihA/[ZMEONIUM CHLORIDE TO FUELS CONTAINING WATER- Waring Blender haze Fuel test, percent light transmission after 6 hrs.

Base heating oil+0.01% polymeric dispersant B 1 4 Base heating oil+0.017 polymeric dispersant B 0.0005% dicoco dimeth yl ammonium chloride added after haze formation 4 Base heating oil+0.005% polymeric dispersant B 1 5 0.0007595 dicoco dimethyl ammonium chloride added after haze fnrmntinn 5 1 Polymeric dispersant B was a mixture of 8 parts of a C tertiary alkyprimary amine and 1 part of a copolymer prepared from 8 parts of Lorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate.

EXAMPLE 6 In order to further test the eifectiveness of dicoco dimethyl ammonium chloride, full-scale tanker tests were carried out by transporting 140,000 barrels of heating oil containing 0.005 wt. percent of a polymeric stabilizing additive in an ocean-going tanker from the Gulf coast to a New Jersey port. The additive employed was a mixture of 8 parts of a'C tertiary alkyl primary amine and 1 part of a copolymer prepared from 8 parts of Lorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate. About 80,000 barrels of the oil contained 0.0005 wt. percent of dicoco dimethyl ammonium chloride. This oil was transported in 7 tanks of the ship. The remaining 60,000 barrels of oil was free of haze inhibitor and was transported in 12 tan-ks of the ship. There was about 4 inches of water in the bottom of each tank.

Upon completion of the voyage, the oil containing, the dicoco dimethyl ammonium chloride and the oil free of the inhibitor were pumped into separate shore tanks of 112,000 barrels capacity. Hourly haze readings (percent haze equals 100 percent transmission relative to fuel filtered bright) were made during the pumping at (1) the line on the dock (2) the line on the shore, and (3) the receiving tank. Haze readings on the line at the dock showed initial values of to with and without the ammonium chloride. The haze thereafter leveled 01f during pumping at from 45 to 5 0% in the oil which did not contain the additive of the invention; whereas haze in the oil'con taining the additive leveled off at from 7 to 8%. The other haze readingsshowedsimilar advantages for the additive.

After completion of the pumping described above, settling of the haze in the two shore tanks was observed at intervals for several days. The results of these observations are shown in the attached drawing. As can be seen from the drawing, the oil containing the dicoco dimethyl ammonium chloride had settled to 10% haze in 20 hours and contained only 1% haze after 62 hours. After 64 flours the oil without the additive had leveled off at 11% aze.

EXAMPLE 7 A turbo-jet engine fuel boiling between 275 F. and 480 F. contains 0.02 wt. percent of a copolymer of 50 parts of decyl methacrylate, 30 parts of octadecyl styrene and 20 parts of 4-vinyl pyridine as a polymeric dispersant stabilizing additive. The water tolerance properties of this fuel are improved by the addition of 0.002 wt. percent of didodecyl dimethyl ammonium chloride.

EXAMPLE 8 A diesel fuel is stabilized by theincorporation therein of 0.01 wt. percent of a copolymer of 80 parts of lauryl acrylate and 20 parts of beta methylamino butyl vinyl ether and 0.08 wt. percent of a mixture of tertiary alkyl 1 1 primary amines derived from C to C polypropylene. To this fuel is added 0.008 wt. percent of dodecyl tetradecy-l dimethyl ammonium chloride in order to improve its water tolerance.

The preceding examples illustrate the efiect of dicoco dimethyl ammonium chloride and closely related compounds upon the formation of persistent haze and stable emulsions in hydrocarbon oils. The dialkyl dimethyl ammonium chlorides having alkyl groups consisting of at least 50% C to C radicals reduce both haze formation :and emulsification even though water extracted; whereas other closely related compounds are ineffective to reduce haze, have no effect upon emulsification, or are almost completely extracted from the oil by small amounts of water. A wide variety of commercial demulsifiers, many of which :are believed to be imidazolinium compounds and other quaternary ammonium salts, have no beneficial effect upon haze formation and emulsification in the presence of polymeric dispersant stabilizing additives or actually increase haze formation in such oils. This singular effectiveness of the additives of the invention permits a significant improvement in the properties of petroleum products, simplifies the handling and storage of such products, and increases their marketability.

What is claimed is:

1. A petroleum distillate fuel boiling in the range between about 75 F. and about 750 F., having incorporated therein from about 0.001 wt. percent to about 1.0 wt. percent of an 'ashless oil-soluble polymeric dispersant stabilizing additive selected from the group consisting of (u) a copolymer of an alkyl chloropropylene-oxy mixed ester of an unsaturated conjugated dibasic acid and a polymerizable organic monomer containing a vinyl group and (b) a nitrogen-containing addition-type copolymer of an amine-free monomer containing one polymerizable ethylene linkage and an aliphatic hydrocarbon chain of from 8 to 18 carbon atoms with a monomer containing a nitrogen atom and one polymerizable ethylene linkage, and from about 0.00025 wt. percent to about 0.01 wt. percent of a dialkyl dimethyl ammonium chloride in which at least 50% of the alkyl groups are C to C radicals.

2. A fuel as defined in claim 1 wherein the concentration of said dialkyl dimethyl ammonium chloride ranges from about 0.0005 wt. percent to about 0.001 wt. percent.

3. A fuel as defined in claim 1 wherein said dialkyl dimethyl ammonium chloride is didodecyl dimethyl ammonium chloride.

4. A fuel as defined in claim 1 wherein said dialkyl dimethyl ammonium chloride is technical dilauryl dimethyl ammonium chloride.

5. A fuel as defined in claim 1 wherein the concentration of said polymeric dispersant ranges from about 0.001 wt. percent to about 0.05 wt. percent.

6. A fuel as defined in claim 1 containing a tertiary alkyl primary amine having from 8 to 18 carbon atoms per molecule in a concentration of from about 2 to about 18 times the concentration of said copolyrner.

7. A fuel as defined in claim 1 wherein the polymerizable organic monomer is a vinyl ester of a short chain fatty acid.

8. A fuel as defined in claim 1 wherein the polymerizable organic monomer is a mixture of an alkyl fumarate and a vinyl ester of a short chain fatty acid.

9. A petroleum distillate fuel boiling in the range between about F. and about 750 F. containing about 0.001 to about 1.0 wt. percent of a copolymer of an acrylic acid ester of a C to C saturated aliphatic alcohol and a tertiary amino alkyl acrylate and from about 0.00025 wt. percent to about 0.01 wt. percent of dicoco dimethyl ammonium chloride.

10. A petroleum distillate fuel boiling in the range between about 75 F. and about 750 F. containing from about 0.001 wt. percent to about 1.0 wt. percent of a copolymer of from about 2 to about l/2O parts of isooctyl chloropropyleneoxy maleate and 1 part of a mixture of vinyl acetate and tallow fumarate and from about 000025 wt. percent to about 0.01 wt. percent of dicoco dimethyl ammonium chloride.

11. A petroleum distillate fuel boiling in the range between about 75" F. and about 750 F. and containing from about 0.00025 wt. percent to about 0.01 wt. percent of dicoco dimethyl ammonium chloride and from about 0.001 wt. percent to about 1.0 wt. percent of a copolymer of a C to C primary alcohol ester of methacrylic acid and? beta diethylaminoethyl methacrylate.

12. A fuel as defined in claim 11 to which has also been added from about 0.003 wt. percent to about 0.8 Wt. percent of a C tertiary alkyl primary amine.

References Cited in the file of this patent UNITED STATES PATENTS 2,550,982 Eberz May 1, 1951 2,737,452 Catlin et all. Matt. 6, 1956 2,805,925 Biswell Sept. 10, 1957 2,861,874 OKel'ly et a1. NOV. 25, 1958 OTHER REFERENCES Surface Active Agents and Detergents, by Schwartz et al., vol. II, copyright 1958, p. 197.

Claims

1. A PETROLEUM DISTILLATE FUEL BOILING IN THE RANGE BETWEEN ABOUT 75*F. AND ABOUT 750*F., HAVING INCORPO RATED THEREIN FROM ABOUT 0.001 WT. PERCENT TO ABOUT 1.0 WT. PERCENT OF AN ASHLESS OIL-SOLUBLE POLYMERIC DISPERSANT STABILIZING ADDITIVE SELECTED FROM THE GROUP CONSISTING OF (A) A COPOLYMER OF AN ALKYL CHLOROPROPYLENE-OXY MIXED ESTER OF AN UNSATURATED CONJUGATED DIBASIC ACID AND A POLYMERIZABLE ORGANIC MONOMER CONTAINING A VINYL GROUP AND (B) A NITROGEN-CONTAINING ADDITION-TYPE COPOLYMER OF AN AMINE-FREE MONOMER CONTAINING ONE POLYMERIZABLE ETHYLENE LINKAGE AND AN ALIPHATIC HYDROCARBON CHAIN OF FROM 8 TO 18 CARBON ATOMS WITH A MONOMER CONTAINING A NITROGEN ATOM AND ONE POLYMERIZABLE ETHYLENE LINKAGE, AND FROM ABOUT 0.00025 WT. PERCENT TO ABOUT 0.01 WT. PERCENT OF A DIALKYL DIMETHYL AMMONIUM CHLORIDE IN WHICH AT LEAST 50% OF THE ALKYL GROUPS ARE C12 TO C14 RADICALS.