US2996366A

US2996366A - Stable fuel oil compositions

Info

Publication number: US2996366A
Application number: US449515A
Authority: US
Inventors: Arthur V Churchill; Mitchell Edward
Original assignee: Gulf Research and Development Co
Current assignee: Gulf Research and Development Co
Priority date: 1954-08-12
Filing date: 1954-08-12
Publication date: 1961-08-15
Anticipated expiration: 1978-08-15

Description

United States Patent OfiFice Patented Aug. l5, 1961 2,996,366 STABLE FUEL OIL COMPOSITIONS Arthur V. Churchill, Oakmont, and Edward Mitchell,

Rosedale, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware No Drawing. Filed Aug. 12, 1954, Ser. No. 449,515 17 Claims. (Cl. 44-66) This invention relates to stable fuel oil compositions, and more particularly to stable fuel oil compositions comprising mixtures of straight run and catalytically cracked fuel oil distillates.

Distillate fuel oil compositions containing mixed straight run and catalytically cracked fuel oil distillates have proved exceptionally troublesome with regard to sludge deposition during storage at normal atmospheric temperatures. It has been found that the sludging characteristics of such mixed, or blended, fuel oil distillates are strikingly poor, much poorer than can be accounted for from the known sludging characteristics of the individual component fuel oil distillates alone. Although the exact cause for the unusual instability of mixed distillate fuel oils is not fully understood, the unusual character and the unexpectedly large volume of sludge formed by such mixed distillate fuel oils have led those skilled in the art to regard the problem of sludge deposition in mixed distillate fuel oils as separate and distinct from that of sludging in other oils.

More particularly, straight run distillate fuel oils contain predominantly parafiinic components. Sludge deposition in these oils, where such occurs, is considered to result from the presence of minor amounts of components that are not normally present and which impart instability to the otherwise stable oils, e.g., impurities picked up during refining, rather than from the inherent instability of the oil itself. The problem of sludge formation in such oils is considered essentially one involving oxidation and the formaton of insoluble oxygenated products.

catalytically cracked fuel oil distillates on the other hand are rich in olefinic, aromatic and mixed olefinicaromatic compounds. Sludging in such oils is considered to involve primarily condensation and/or polymerization type reactions which result in the formation of insoluble reaction products of relatively high molecular weight.

Still further, sludge deposition in blends of straight run and catalytically cracked fuel oil distillates is an entirely distinct problem from that for either component oil. While the sludge formed in such blended fuel oils very probably contains some sludge of the type formed in each component oil, the sludge formed in blended fuel oils is consistently greatly in excess of the amount that can be accounted for from the known sludging tendencies of the individual component oils, thus indicating the existence of a special problem.

The problem of sludge deposition in mixed straight run and catalytically cracked fuel oil distillates is not only separate and distinct from that of sludge deposi-: tion in individual distillate fuel oils, but also from that of sludge deposition in lubricating oils and from that of gum formation in gasolines. In the former instance sludge formation is attributed to the high temperature oxidation of the highly parafiinic components contained in the loil, the reaction of acidic oxygenated products with metals contacted therewith, and, in the caseof crankcase lubricants, sludge formation is additionally attributed to the presence of foreign materials such as water, dust particles, carbon, incompletely burned fuel and the like.

Gum formation in gasolines on the other hand is attributed primarily to the oxidation of olefinic linkages (as opposed to oxidation of parafiinic compounds). Moreover, the gums formed in gasoline are not normally insoluble in the fuel as is the case with sludge; instead, deposition of gums from gasoline occurs upon vaporization of the latter, rather than during storage as is the case with blended fuel oils.

The present invention relates to fuel oil compositions comprising mixed catalytically cracked and straight run fuel oil distillates, which compositions possess improved sludging characteristics. It has been found that. such improved distillate fuel oil compositions can be obtained by incorporating in the mixed oil a small, sludge inhibiting amount of a salt of a carboxylic acid containing at least 8 carbon atoms per molecule and a 1,3-diaminopropane having the general formula:

where R is an aliphatic radical containing from 8 to 30 carbon atoms. For example, excellent results are obtainable with fuel oil compositions having incorporated therein small amounts of the carboxylic acid salts of 1,3-diaminopropanes of the type indicated above, where R is an alkyl or alkenyl group containing 12 to 18 carbon atoms.

The addition of very small amounts of salts of the foregoing type to blended distillate fuel oils containing both straight run and catalytically cracked components has been found to produce a marked improvement in the sludging tendencies of the oils. Naturally, the various individual salts of the herein disclosed class do not possess exactly identical effectiveness, and the most advantageous concentration for each such salt will depend to some extent upon the particular compound used. Also, the minimum effective inhibitor concentration may vary somewhat according to the nature of the mixed fuel oil utilized. In general, however, the herein disclosed salts are useful in concentrations of as little as about 0.005 percent, up to about 1.0 percent by weight of the composition. Major improvement of the sludging characteristics of mixed fuel oils is usually obtainable by incorporation therein of from about 0.01 to about 0.05 percent by weight, of a salt of the herein disclosed class. However, in some cases it can be advantageous to add as much as 0.1 percent by weight of the inhibitor, and in unusual instances it may even be desirable to add as much as 1. 0 percent by weight of the inhibitor.

The inhibitor compounds included by this invention may be incorporated in the mixed fuel oil in any suitable manner. Thus, the salts may be formed in situ in the oil, or they may be added, per se, to the mixed fuel oil, either directly or in the form of concentrated solutions or dispersions, either immediately after the mixture of distillate fuel oils is formed or after the mixture has been stored for a substantial period of time. In the latter case, the additives of this invention tend to transform previously formed sludge into an unobjectionable form. Alternatively, the sludge inhibiting salts of this invention may be formed in situ in, or added per se or in the form of concentrated solutions or dispersions to, either the straight run or the catalytically cracked fuel oil distillates prior to blending of these components to form a mixed fueloil. In either case, addition of the preformed additives is preferred. Suitable concentrates containing the inhibitor compounds of this invention comprise, for example, mineral oil solutions or dispersions containing from about 20 to weight percent, and preferably from about 40 to 60 weight percent active ingredient. In instances where the concentrates are in the form of dispersions it may be desirable to heat the concentrates and/or the fuel oil distillates to be inhibited, e.g. to a temperature of from to F.,

the diamine in a 2:1 mol ratio.

in order to expedite blending. An alternative practice involves the use of concentrated solutions of the disclosed inhibitors in solvents, other than mineral oils,

which have a high degree of solubility for the inhibitors of this invention and which do not adversely affect the sludging tendencies of the distillate fuel oils. Examples of such concentrates are the 50 weight percent solutions of the monoand dioleates of 3-tallow-aminopropylamine in benzene, isopropanol and methyl isobutyl ketone.

The class of distillate fuel oils to which this invention is applicable includes mixtures of straight run and catalytically cracked distillate fuel oils such as areused for domestic heating and for heating purposes in some industrial processes, typical of which are the so-ealled No. 2 fuel oils, i.e., distillate oils boiling within the approximate range of 350 to 750 F. andhaving a minimum API gravity of about 26. i i

The problem of stabilizing such oils, with which problem the present invention is concerned, is unique, and it exists only when a catalytically cracked fuel oil distillate and a straight run fuel oil distillate are combined in such proportions as to cause a substantial effect of the kind previously described. The invention is important when the ratio of thevolume of the catalytically cracked to the straight run oil iswithin the range of about 9:1 and about 1:9. It is especially advantageous when applied to mixed oils containing these oils in a volume ratio within the range of 4:1 and 1:4.

As indicated, the salts that are useful for the purposes of this invention are carboxylic acid salts of 1,3-diaminopropanes that contain a secondary amine grouping. Such salts are prepared by neutralization with a carboxylic acid of one or both of the amino groups of a 1,3-diaminopropane that contains a secondary amino grouping. The neutralization reaction normally takes place spontaneously at room temperature with evolution of heat, but in some cases moderate heating may be desirable in order to accelerate the reaction. In no case should the reaction be carried out at temperatures in excess of about 195 F., since decomposition of the ammonium salt may occur with prolonged exposure to temperatures substantially in excess of this limit. The mol ratio of the reactants, i.e., the carboxylic acid and the diamine, varies according to the degree of neutralization desired and according to the number of carboxyl groups in the acid,

lesser amounts of polycarboxylic acids being required for the desired degree of neutralization than of monocarboxylic acids. By way of illustration, partial neutralization of the 1,3-diaminopropanes may be obtained by reacting a monobasic carboxylic acid with the diamine in a 1:1 mol ratio, and complete neutralization may be obtained by reacting a monobasic carboxylic acid with partial neutralization of the diamine may be obtained by reacting a dibasic acid therewith in a 1:2 mol ratio and complete neutralization of the diamine may be ob tained by reacting a dibasic acid therewith in a 1:1 mol ratio.

The diaminopropanes that form salts included by this invention may be illustrated by the generic formula:

where R is an aliphatic radical containing from 8 to 30 carbon atoms. Thus, the present invention includes, for example, the use of salts of long chain alkyl-, alkenyland alkadienylaminopropylamines. Specific examples of such compounds are salts of the hereinafter disclosed carboxylic acids and 3-octylaminopropylamine, 3-tetradecylaminopropylamine, 3 tetradecenylaminopropylamine, 3 eicosylaminopropylamine, 3 eicosenylaminopropylamine, and V 3 triacontanylaminopropylamine. Within the general class of the carboxylic acid salts of l,3-diaminopropanes included by this invention, the salts On the other hand, the

and cyclohexyl stearic acids.

secondary amine grouping contains at least 12, and preferably from 12 to 18, carbon atoms are especially effective. Examples of salts considered to be exceptionally effective are the carboxylic acid salts of the 3-dodecyl-, the 3-hexadecylaminopropylamines, and especially the 18 carbon alkyl-, alkenyl-, and alkadienylaminopropylamines, such as the 3-octadecyl-, 3-octadecenyl-, and 3- octadecadienylaminopropylamines. Although salts of aliphatic hydrocarbon N-substituted 1,3-diaminopropanes are preferred, the invention also includes salts of diamines in which the N-substituent of the secondary amine grouping is itself substituted with one or more groups that contain elements such as oxygen, sulfur, nitrogen or halogen, and that do not interfere with the oil-solubility of the salt. Representative examples of carboxylic acid salts of 1,3-diaminopropanes containing substitutents of this kind are salts of 3-ricinoleylaminopropylamlne and- 3-(chlorostearyl)aminopropylamine.

Carboxyl-ic acids that form salts included by this invention are oil-soluble monoor polybasic carboxylic acids which contain at least 8 carbon atoms per molecule and which are capable of reacting with a diamino compound of the kind described above to form a substituted ammonium salt. The invention particularly includes salts of long chain, saturated or unsaturated, oil-soluble fatty acids. Specific examples of such acids include caprylic, myristic, tetradecenoic, arachidic, eicosenoic and triacontanoic acids. Mixtures of long chain fatty acids such as those obtained from the saponification of natural fats and oils are also suitable. Examples of such acids are coconut, soya, tallow and tall oil fatty acids. Theinvention is not limited to the use of salts of open'chain carboxylic acids but also includes salts of alicyclic oilsoluble carboxylic acids, such as, for example, alkyl cyclopentanoic acids, alkyl cyclohexanoic acids, and the naphthenic acids, e.g., the mixed, alicyclic monocarboxylic acids recovered by alkali washing of petroleum distillates such as kerosene, naphtha, gas oil, and lubricating distillates. The thus'derived acids are considered to comprise mixtures containing from about 7 to 30 carbo'n atoms per molecule, which mixtures have average molecular weights ranging from about 200 to about 450. The invention not only includes the salts of petroleum naphthenic acids but also the salts of synthetic naphthenic acids, such as cyclohexyl acetic, cyclohexyl propionic,

The invention further includes the use of salts of oil-soluble polybasic carboxylic acids. Representative examples of such salts are salts of azelaic, sebacic, dodecanedioic and hexadecanedioic acids, as well as dimerized unsaturated fatty acids such as dilinoleic acid. Other suitable oil-soluble disbasic carboxylic acids are the long chain alkyl or alkenyl, or cycloalkyl substituted succinic acids or similarly substituted glutaric or thiaglutaric acids, representative examples of which are dodecenylsuccinic acid and 2,4-dinaphthenyl,3- thiaglutaric acid. The latter may be prepared as indicated in the copending application of Pellegrini et al, Serial No. 387,308, filed October 20, 1953, now abandoned. The invention includes acids "which are substituted with groups containing sulfur, oxygen, halogen, etc., which do not adversely afiect the oil-solubility thereof, such as ricinole ic acid or chlorostea'ric acid. 7

It is not necessary that either the oil-soluble carboxylic acid or the N-substituted 1,3-diaminopropane :be employed in pure form. If desired, mixed salts formed by reacting mixed carboxylic acids, such as those derived from the saponification of natural oils or fats, the mixed N-substituted 1,3-diaminopropanes, such as those resulting when the aliphatic N-substituent of the secondary amine grouping is a monovalent aliphatic hydrocarbon radical derived from mixtures of fatty. acids obtained from naturally occurring fats and oils. In such cases the N-substituents will be monovalent, straight chain hydrocarbon radicals containing from 8 to 20 carbon atoms.

Thus, for example, the mixed, coconut, soya or tallow fatty acid salts of 3-tallow"-, 3-soyaor 3-cocoaminopropylamines are satisfactory for the purposes of this invention, where the respective N-substituents are mixed alkyl and unsaturated alkyl groups derived from animal tallow (C fatty acids, soybean (C fatty acids, and coconut (C fatty acids.

The effectiveness of the herein disclosed class of salts to improve the sludging characteristics of mixed straight run and catalytically cracked distillate fuel oils is considered to be peculiar thereto in view of the fact that carboxylic acid salts of low molecular weight alkylene diamines, even though of similar structure, not only fail appreciably to inhibit sludge deposition in such mixed distillate fuel oils, but in many instances actually function as sludge accelerators.

The utility of the herein disclosed class of carboxylic acid salts of N-substitluted 1,3-diaminopropanes has been demonstrated by subjecting mixtures of catalytically cracked and straight run fuel oil distillates containing various representative salts of the class included by the invention to a standard, accelerated stability test. The test samples were made up by adding the desired concentration of each additive to be tested to separate samples of various fuel oil mixtures containing 50 percent by volume Eastern Venezuela straight run No. 2 fuel oil distillate and 50 percent by volume catalytically cracked No. 2 fuel oil distillate and having varying sludging characteristics. The results of the testing of fuel oil compositions containing the following additives are presented elsewhere herein as illustrative of the lbenefits obtainable by this invention: the monooleate of 3-tallow-aminopropylamine (prepared by reacting oleic acid and 3- tallow-aminopropylamine in a 1:1 mol ratio), the dioleate of 3-"tallow-aminopropylamine (prepared by reacting oleic acid and 3-tallow-aminopropylamine in a 2:1 mol ratio), the substantially neutral diammonium 2,4-dinaphthenyl-3-thiaglutarate of 3t2LllOW-3Hhil101)l0- pylamine (prepared by reacting 2,4-dinaphthenyl-3- thiaglutaric acid and 3-tallow-aminopropylamine in a 1:1 mol ratio), the di-(3-an1inopropyl, tallow-ammonium)2,4-dinaphthenyl-3-thiaglutarate (prepared by reacting 2,4-dinaphtl1enyl-3-thiaglutaric acid with 3-tallow-aminopropylamine in a 1:2 mol ratio), the mononaphthenate of 3-"tallow-aniinopropylamine (prepared be reacting petroleum naphthenic acids with 3-tallowaminopropylamine in a 1:1 mol ratio), the dinaphthenate of 3-tallow-aminopropylarnine (prepared by reacting petroleum naphthenic acids with 3-tallow-aminopropylamine in a mol ratio of 2:1), the mono-(Z-ethylhexoate) of 3-"tallow"-aminopropylamine (prepared by reacting 2- ethylhexoic acid with 3-tallow-aminopropylamine in a 1:1 mol ratio), and the di-(Z-ethylhexoate) of 3-tallowaminopropylamine (prepared by reacting Z-ethylhexoic acid with 3-"talloW-aminopropylamine in a 2:1 mol ratio). The naphthenic acids referred to above had an average molecular weight of 258 and a boiling range of 150 to 196 C. at 0.7 to 0.9 of mercury.

In order to illustrate by comparison the unique nature of the benefits obtainable from the use of the paitioular class of salts included by this invention, there are also presented below the results obtained from testing similarly compounded and tested fuel oil compositions containing the mono and dinaphthenic acid salts of ethylene diamine (prepared by reacting naphthenic acids and ethylene diamine in a 1:1 and a 2:1 mol ratio).

The 3-"tallow-aminopropylamine previously adverted to was a mixture containing about 80 percent active ingredients, calculated as diamines, wherein the N-substituent of the secondary amine grouping was a mixture of alkyl and alkenyl radicals containing from 14 to 18 carbon atoms derived from the mixed fatty acids obtained from the saponification of animal tallow. The mixture contained predominantly 3-octadeceny1aminopropylamine,

or 3-oleylaminopropylamine, together with lesser proportions of 3 -octadecyland 3-hexadecylaminopropylamines and still smaller proportions of 3-octadecadienyland 3- tetradecylaminopropylamines. The mixture had a melting range of 44 to 48 C., a theoretical molecular weight of 320 and a combining weight (calculated on percent active ingredients) of 400.

The stability test referred to above was carried out on the above-indicated mixed fuel oil compositions by heating 600 gram samples of the fuel oil compositions for a period of 16 hours at 210 F. in loosely stoppered, onequart, clear glass bottles. Following the heating period each test sample was cooled to room temperature and filtered by suction through a tared, medium porosity, fritted glass Gooch-type crucible. The sludge in each crucible was washed with heptane. Complete removal of the sludge adhering to the inside of the bottles was obtained by means of a rubber policeman and heptane. The respective crucibles were dried in an oven maintained at 210 F. for 1 hour, cooled in a desiccator and reweighed. The increase in weight was recorded as milligrams of sludge per 600 grams of oil.

The results obtained in the testing of the above-described fuel oil compositions are set forth below in tabular form. The fuel oil blend referred to as Blend A in the table was found to have an API gravity of 28.7, a specific gravity (60/60 F.) of 0.8833,. a viscosity of 35.6 SUS at R, an NPA color of 2-, a bromine number of 16.5, a pour point of 0 R, an olefin content of 22.3 weight percent (calculated), an aromatic content of 26.2 volume percent, a flash point of R, an aniline point of 116 R, an acid number of 0.05, an ash content of less than 0.01 percent, calculated as oxides, an initial boiling point of 385 F. and an end point of 642 F. The foregoing values are typical of, although not necessarily identical with, those obtained for Blend B and Blend C.

Table A Sludge, Fuel Oil Compositions mg./60O g. Oil, After 16 Hrs.

1. Blend A50/50 Mixture of E.V.S.R. and F.C.C. N0. 2

Fuel Oil Distillate 18. 2 2. Blend A plus 0.02 Wt. Percent Monooleate of 3-T low-aminopropylamine 2. 0 3. Blend A plus 0.02 Wt. Percent Dioleate of 3-Tallowaminopropylamine 2. 3 4. Blend A plus 0.05 Wt. Percent 2,4-Dinaphthenyl-3- Thiaglutarate of 3-.Ta1low"-ami110propylamine 5. 1 5. Blend A plus 0.05 Wt. Percent di-(3-Aminopr0pyl- Tallow-am1noniu m)-2,4-Dinaphthenyl-3-Thiaglutarate 3.1 6. Blend A plus 0.05 Wt. Percent Mouonaphthenate oi 3- Tallow-an1inupropylamine 1. 3 7. Blend A'plus 0.02 Wt. Percent Mononaphthenate 01' 3- "Tallow-aminopropylamine 4. 2 8. Blend A plus 0.01 Wt. Percent Mononaphthe TalloW-an1i nopr0pylamine 4. 6 9. Blend A plus 0.05 Wt. Percent Mono-2-Ethy1hex0ate of 3-Tallow"-arninopropylamine 3. 9 l0. Blend A plus 0.05 Wt. Percent Di-2-Ethylhexoate of 3- "Tallow"-aminopropylamine 4. 9 11. Blend B50/50 Mixture of E.V.S. and FCC. N0. 2

Fuel Oil Distillate 9. 8 12. Blend B plus 0.05 Wt. Percent Dinaphthenate of 3- "Tallovv-amin0propylamine 3. 9 13. Blend C50/50 Mixture of E.V.S.R. and F.C.C. No. 2

Fuel Oil Distillate 31. 8 14. Blend 0 plus 0.02 Wt. Percent Ethylenediamine Mononaphthenate 315. 0 15. Blend 0 plus 0.02 Wt. Percent Ethylenediamine Dina phthenate 34. 8

Compositions 2, 3, 4, 5, 6, 7, 8, 9, 10 and 12 in the foregoing table are specific embodiments of the invention. The results shown in the table for these compositions are considered typical of those obtainable with the carboxylic acid salts of the class included by the invention. Comparison of the results obtained for Compositions 2 to 10, inclusive, and for Composition 12 with the results obtained for corresponding blank Compositions 1 and 11 clearly indicates the marked improvement in the sludging characteristics of mixed distillate fuel oils I that is obtainable with the salts included by this invention. On the other hand, comparison of the sludging characteristics of Compositions 14 and with those of corresponding blank Composition 13 indicates that salts other than those included by the invention, even though of related structure, do not improve the sludging characteristics of mixed catalytically cracked and straight run fuel oils. Indeed, many such compounds, as shown by the results set forth in the table for Composition 14, have a marked detrimental effect upon the sludging tendencies of said mixed'fuel oils.

The sludge inhibiting additives of this invention are especially advantageous in that they are. essentially ashless in character.

It will be understood that the foregoing specific embodiments of the invention are merely illustrative and that other members of the class of sludge inhibiting salts included by the invention can be used in the same concentrations or in other equivalent concentrations within the ranges disclosed, to prepare mixed catalytically cracked and straight run fuel oil compositions having similarly improved sludging characteristics. Examples of other specific embodiments of the invention are mixtures of straight run and catalytically cracked fuel oil distillates within the ratios of 9:1 and 1:9 by volume, e.g., 411,2:1, 1:1, 1:2 and 1:4 by volume, having incorporated therein from' 0.005 to 1.0 percent by weight, e.g., 0.01, 0.02, 0.03, 0.04, 0.05, 0.1 percent by weight, of the monoand dilaurates, monoand dimyristates, monoand dipalmitates, monoand distearates, monoand dilinoleates and monoand dinaphthenates of 3-dodecylaminopropylamines, 3 -tetradecylaminopropylamine, 3- hexadecylarninopropylamine, 3 octadecylaminopropylamine and 3-octadecenylaminopropylamine. Examples of other suitable compounds which can be substituted in the foregoing embodiments are salts 'of sebacic acid, azelaic acid, dodecyl, dodecenyl, and octadecyl succinic acids and the foregoing N-substituted aminopropylamines.

If desired, the stable fuel oil compositions of this invention may contain, in addition to the additives disclosed herein, other improvement agents such as for example, oxidation inhibitors, flash point control agents, corrosion inhibitors, anti-foam agents, ignition quality improvers, combustion improvers and other additives adapted to improve the oils in one or more respects.

It will be apparent to those skilled in the art that many modifications and variations of the invention may be resorted to without departing from the spirit thereof. Accordingly, only such limitations should be imposed as are indicated in the claims appended hereto.

We claim:

1. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending'to deposit sludge and containing a small amount of an oil-soluble salt of a carboxylic acid that contains 1 to 2 carboxyl groups and at least 8 carbon atoms per molecule, and a compound of the type indicated by the general formula:

cent by weight of said mixture of oils.

4. The fuel oil composition of claim 1 wherein R is a radical selected from the group consisting of alkyl and alkenyl groups containing 12 to 18 carbon atoms. 7

5. A fuel oil composition comprising a major proportion of a mixture of straight run and oatalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a monooleate of 3.-octadecenylaminopropylamine, said small amount being sufficient to inhibit sludge deposition from said mixture of oils.

6. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a monooleate of mixed 3-alkyland 3-alkenylaminopropylamines wherein said alkyl and alkenyl substituents contain 14 to 18 carbon atoms, and the predominant substituent is octadecenyl, said small amount being sufficient to inhibit sludge deposition from said mixture of oils.

7. A fuel oil composition comprising a major proportion of a mixture of straight run and catalyticaly cracked distillate fuel'oils tending to deposit sludge and containing a small amount of a dioleate of 3-octadecenylaminopropylamine, said small amount being sufficient to inhibit sludge deposition from said mixture of oils.

8. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a dioleate of mixed 3-alkyland 3-alkenylaminopropylamines wherein said alkyl and alkenyl substituents contain 14 to 18 carbon atoms, and the predominant substituent is octadecenyl, said small amount being sufficient to inhibit sludge deposition from said mixture of oils.

9. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing'a small amount of a mono-2-ethylhexoate of 3octyldecenylaminopropylamine, said small amount being suflicient to inhibit sludge deposition from said mixture of oils.

10. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked tion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a di-Z-ethylhexoate of 3-oc t adecenylaminopropylamine, said small amount being sufficient to inhibit sludge deposition from said mixture of oils. I

12. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a di-Z-ethylhexoate 'of mixed 3- alkyland 3-alkenylaminopropylamines wherein said alkyl and alkenyl substituents contain 14 to 18 carbon atoms, and the predominant substituent is octadecenyl, said small amount being sufficient to inhibit sludge deposition from said mixture of oils.

13. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a mononaphthenate of 3-octadecenylaminopropylamine, said small amount being sulficient to inhibit sludge deposition from said mixture of oils.

14. 'A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a mononaphthenate of mixed 3-alkyland 3-alkenyla1r1inopropylamines wherein said alkyl and alkenyl substituents contain 14 to 18 carbon atoms,

a and the predominant substituent is octadecenyl, said small amount being sufiicient to inhibit sludge deposition from said mixture of oils.

15. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a dinaphthenate of 3-octadecenylaminopropylamine, said amount being suflicient to inhibit sludge deposition from said mixture of oils.

16. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a dinaphthenate of mixed 3-alkyland 3-alkenylaminopropylamines wherein said alkyl and alkenyl substituents contain 14 to 18 carbon atoms, and the predominant substitutent is ootadecenyl, said small amount being sufficient to inhibit sludge deposition from said mixture of oils.

17. A fuel oil composition comprising a major proportion of a mixture of straight-run and catalytical-ly cracked distillate fuel oils tending to deposit sludge and contain- References Cited in the file of this patent UNITED STATES PATENTS 2,329,251 Chenicek Sept. 14, 1943 2,684,292 Caron et a1. July 20, 1954 2,688,595 Fainman Sept. 7, 1954 2,700,612 Ohenicek J an. 25, 1955 2,736,641 Mattson et a1 Feb. 28, 1956 2,736,658 Pfohl et a1 Feb. 28, 1956 2,771,348 Meguerian Nov. 20, 1956

Claims

1. A FUEL OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF A MIXTURE OF STRAIGHT RUN AND CATALYTICALLY CRACKED DISTILLATE FUEL OILS TENDING TO DEPOSIT SLUDGE AND CONTAINING A SMALL AMOUNT OF AN OIL-SOLUBLE SALT OF A CARBOXYLIC ACID THAT CONTAINS 1 TO 2 CARBOXYL GROUPS AND AT LEAST 8 CARBON ATOMS PER MOLECULE, AND A COMPOUND OF THE TYPE INDICATED BY THE GENERAL FORMULA: