US2941876A - Middle distillate fuel composition - Google Patents

Description

United States Patent Q MIDDLE DISTILLATE FUEL COMPOSITION Maurice E. Stanley and Levi C. Parker, Port Arthur,

Tex., assignors to Texaco Inc., a corporation of Delaware This invention relates to a hydrocarbon fuel composition having improved non-corrosive and stability properties. More particularly, this invention relates to a hydrocarbon fuel composition having incorporated therein a high ester content, high viscosity oxidate which has the dual function of an anti-corrosive and a dispersant in the fuel. This application is a continuation-in-part of copending application S.N. 636,514, filed January 28, 1957, now abandoned.

Petroleum oxidates have been proposed as rust inhibitors in almost every type of petroleum fraction. Although rust and corrosion protection are of great importance in petroleum fractions utilized as fuels, there is also a definite need to provide protection against deposit formation. The problem of deposit formation is more prevalent in the middle distillate fuels, for example, diesel fuels, jet fuels and furnace oils which have been subjected to oxidizing conditions, such as long storage which in turn causes deterioration as evidenced by sludge and sediment formation. Usually, when deposit-forming tendencies exist in a fuel, an additive specifically designed to combat oxidation or a dispersing additive, to keep the deposits from fouling the system, is incorporated in the fuel.

In accordance with the present invention a fuel composition boiling within the range of middle distillate fuels has incorporated therein a rust inhibiting and a depositdispersing amount of a special type of petrolatum oxidate characterized by a ratio of neutralization number (neut. No.) to saponification number (sap. No.) below about 0.25 and a viscosity (Saybolt Universal) at 210- F. of at least about 1,500 seconds to about 20,000 seconds and preferably in the range of about 2,500 to 12,000 seconds. This special type of petrolatum oxidate is unique in imparting both anti-rust and dispersant properties to middle distillate fuels. Suitable petrolatum oxidates of this character have a maximum neut. No. of about 35, sap. No. between about 100 and 155, and contain not more than about 50 percent of unsaponifiables.

The petrolatum oxidates employed in these compositions are obtained by oxidizing petrolatum with air in the presence of a catalyst at an air'feed rate of to 35 standard cubic feet of air, per pound of hydrocarbon, per hour, at a temperature between 270 and 400 F. and at atmospheric pressure. The preferred feed stocks employed for obtaining the oxidates for use according to this invention are heavy petrolatum suitably containing from about 1 to 25 percent of oil obtained from naphthenic, paraflinic or mixed base crude oils. Under the above conditions the viscosity of the oxidate increases rapidly during the oxidation and if the oxidation period is extended sufficiently, it becomes a plastic mass at 210 F. With the type of feed stock described, the neut. No. also increases under these conditions to a maximum value of about 35 and the sap. No. to a maximum value of about 155. The oxidation is carried out until a product is obtained having a viscosity of at least about 1500 seconds Saybolt Universal at 210 F., and preferably between 7 Patented June 21, 1960.

2,5 00 and 12,000 seconds, although more viscous products may be employed if desired. A more complete explanation of the method of preparation and examples thereof are set forth in US. Patent No. 2,705,241, issued March 29, 1955, to John K. McKinley, Gordon S. Bright, and Roy F. Nelson.

The deposit dispersing amount of the high ester con tent high viscosity petrolatum oxidates of-this invention ranges from 2 to pounds per thousand barrels of base fuel. The preferred amount, however, on the basis of economy and performance ranges from 5 to 20 pounds per thousand barrels of fuel.

The middle distillate fuels in which the high ester content, high viscosity petrolatum oxidates are effective dispersants and anti-rust agents include hydrocarbon fractions boiling within the range of about 100 to about 750 F. or within the jet fuel to light gas oil range. Included along with straight run middle distillate fuels, are thermal and catalytically cracked hydrocarbon fuels and mixtures of cracked fuels and straight run fuels distilling within the given range. Both the cracked fuels as well as the blends of cracked and straight run fuels may be acid or caustic treated to improve their stability. Middle distillate fuels which have a marked tendency toward sludging and deposit formation are primarily cracked fuels or blends which are composed mainly of cracked fuels. The

so-called light and intermediate cycle gas oil fractions from thermal cracking and catalytic cracking, and which are economically used in furnace oil blends and economy diesel fuels, are particularly prone to form deposits.

Included within-the scope of this invention are middle distillate fuel compositions containing the prescribed high ester content high viscosity petrolatum oxidate, in combination with a Schiffs base reaction product of 1 mole of an aliphatic polyamine having two primary amino groups with 2 moles of an aromatic aldehyde. Schifis base reaction products have the general formula: I j

where A represents an aromatic nucleus and R is an aliphatic radical having two nitrogen atoms attached 'directly to different carbon atoms on the same open chain. Compounds of this type which generally are used in a concentration of about 0.5 to 10 pounds per thousand barrels of fuel in combination with the petrolatum oxidate disalicylidene-1,Z-diaminopropahe.

normally act as metal deactivators as disclosed in the Downing et a1. U.S. Patent No. 2,282,513. A' preferred compound of this class, which is commercially available, is disalicylal propylenediamine which is also known as Examples of other compounds of this type are the following: di-(Z-hydroxy- 3-methoxybenzal) ethylenediamine, di-(Z-hydroxybenzal) ethylenediamine, di-(2-hydroxybenzal) decamethylenediamine, di-(Z-hydroxybenzal) triethylenetetramine, di-(Z- hydroxybenzal) hexarnethylenediamine, di-(Z-hydroxybenzal) 1,3-propylenediamine, dibenzal ethylenediamine, dibenzal hexamethylenediamine, dibenzal diethylenetriamine, dibenzal triethylenetetramine, and disalicylal ethylenediamine.

These metal deactivators by themselves do not act as fuel stabilizers but, surprisingly, when used in combination with a high ester content, high viscosity petrolatum oxidate, they lend added stability to the fuel which in turn prevents color degradation of the fuel-petrolatum oxidate mixture after storage. The preferred additive amount of this compound in the fuel is from about 1 to 5 pounds per thousand barrels.

A number of tests were used in the development of the stable fuel compositions of this invention. The basic deposit determination test involved vigorously shaking the fuel composition'which had been stored for a period of time to obtain a representative sample. A 150 ml. sample was removed and filtered under vacuum through a No. 1 Whatman filter paper disc. The filterdiscs were retained for visual observation and comparison of the discoloration due to retained sediment.

The following table showing the results of the above test is set forth to demonstrate the stability of a fuel composition of this invention as compared to the. base fuel and several other related type fuel compositions.

The base fuel comprised a blend of 30 vol. percent of a heavy kerosine distillate having an API gravity below 42 derived from an asphalt base crude and 70 vol. percent of a fluid cracked light cycle gas oil. Test results on the base fuel were as follows:

Gravity, API Flash, P.M., F. 172 Viscosity, S.U. 100 F. 34.0 Color, ASTM 2.5 Pour, F. 7 -25 Carbon residue (10% btms.) 0.02 Corn, cu. strip at 122 F Neg. 1 Sulfur, wt. percent 0.22 Ash, wt. percent None Cetane No. 41.4 Aromatics, vol. percent 24 Olefins, wt. percent Distillation, F.:

I.B.P. 386

In this test the comparative terms of very slight, slight, medium, heavy, and very heavy, to designate the amount of deposits or sediment on each filter disc, were used.

In the following table and in subsequent tables the amount of additive given as present in the base fuel and the description thereof is based on the active ingredients. Oxidates A and B, which were derived from petrolatum and paraffin waxes, respectively, are completely soluble in middle distillatefuels. However, in order to facilitate handling, each of these oxidates was cut back with a portion of thebase fuel prior to incorporation in the fuel tested. On the other hand, the acid-type paraffin wax oxidate from which oxidate C was derived was only about 75 to 80 percent soluble in a middle distillate fuel. Accordingly, this soluble portion of this. acid-type oxidate material was termed oxidate C and the cut-back oxidate was added in the desired amount to the fuel tested. The additive. amounts shown in the tables in each case were considered to be equivalent thereby allowing comparison of the effectiveness of these oxidates.

TABLE I Basic deposit determination test The oxidate A" in the above table was a high ester content, high viscosity microcrystalline petrolatum oxidate having a neut. No. of 25, a sap. No. of 145, and neut. No. to sap. No. ratio of 0.17 and an unsaponifiable content lessthan 50 percent. Oxidate B consisted of an ester type macrocrystalline .wax oxidate having a neut. Nani 84, 21 san. No. of 230 a neut. No. tqfi pratio of 0.37 and an unsaponifiable content less than 40 percent. Oxidate C consisted of the fuel soluble portion (75 to percent solubility) of an acid-type macrocrystalline wax oxidate having an average neut. No. of 232, an average sap. No. of 380, an average neut. No. to sap. No. ratio of 0.61, and an unsaponifiable content less than 16 percent.

The results in the above table demonstrate the particularity of the invention with respect to the specific oxidate necessarily employed in obtaining a stable fuel composition.

The petrolatum oxidate of the invention has a much lower neut. No. to Sap. No. ratio than those wax oxidates showing no dispersing properties. Oxidate A also differs from oxidates B and C in that it is a microcrystalline wax oxidate rather than a macrocrystalline.

Another test used in the determination of the dispersant qualities of the fuel compositions of this invention was the accelerated filter paper depositv test which consisted of placing a 170 ml. sample of the fuel in a Pyrex glass cell and heating the fuel sample for 2 hours at 275 F. by means of a bath in which the cell was immersed. The glass cell was provided with air inlet means at the bottom thereof through which air could be forced or bubbled through the fuel sample therein. Air was bubbled through 20 percent caustic and Water andv then through the middle distillate fuel sample in the cell at the rate of 0.3 liter per hour. At the end of 2 hours at 275 F., the fuel was removed and cooled to room temperature within approximately 1 hour after removal. sample of the fuel was then filtered under vacuum through a No. 1 Whatman filter paper disc. The filter discs were retained for visual observation and comparison of the discoloration due to retained sediment.

In Table II there is shown the improvement obtained in the accelerated filter deposit test by adding a high ester content, high viscosity petrolatum oxidate to the base fuel described in Table I. For purposes of comparison, there are also shown the results obtained in this test by adding two different parafiin wax oxidates to the same base fuel. The samples were not stored prior to testing.

TABLE II Accelerated filter deposit test Fuel Sample Deposit Formation Base f l heavy. Bass fuel 12 lbs. of Oxidate A 1,000 bhls. of fuel slight. Base fuel 12 lbs. of Oxidate B/l,000 bbls. of fueL. heavy. Base fuel-+ 12 lbs. of Oxldate 011,000 bbls. of fuel heavy.

The accelerated deposits test was designed to simulate a situation wherein the fuel composition had been exposed to oxidizing conditions for a lengthy period. It can be seen from the above table that the oxidate of this invention (oxidate A) is extremely effective in reducing deposit formation. On the other hand, the more acidic macrocrystalline wax oxidates (B and C) are ineffective with respect to dispersant qualities.

In order to ascertain the ability of a high estercontent, high viscosity petrolatum oxidateto stabilize the depositforming tendencies of the fuel after actual storage for comparatively long periods of time, several fuel compositions of interest including the fuel composition of the invention were held in vented dark storage at room temperature for sixand twelve-month periods. These samplcs were then evaluated basis (1) visual observation of storage samples, (2) color, carbon residue, and insoluble residue of storage samples, and (3) basic deposit determination tests.

The base fuel used during this phase of experimentation was that described in connection with the experiments shown in Table I.

The results from the visual observations o the deposits formed during the sixmonths storage at room temperature indicated that the high ester content, high viscosity petrolatum oxidate of the invention in a dosage of 12 lbs. per thousand barrels of fuel significantly reduced deposit formation. It appears to be rather generally agreed throughout the industry that observation of room temperature samples for deposits after long-term storage is the best single criterion for establishing the stability of middle distillate fuels.

The color of the fuel composition of the invention had satisfactory stability. The original N.P.A. color was L2 /2. After six months storage the sample had darkened to only L3.0, and after twelve months storage the sample had darkened to L3 /z.

The amount of carbon residue present was also very satisfactory. Analysis of percent bottoms after six months storage showed only 0.08 wt. percent. No carbon residue determination was made after twelve months storage.

Insoluble residue, basis the Du Pont F 8-52 residue test was also very slight. The results of this test 'on the fuel composition of the invention after six months storage showed only 0.7 mg. per 100 ml. and 1.0 mg. per 100 ml. after twelve months.

The following table shows the results of the basic deposit determination test on the fuel compositions stored for six and twelve months.

TABLE III Again, after sixand twelve-month storage periods the fuel composition of the invention with oxidate A showed a marked ability to stabilize deposit formation in the fuel. The more acidic paraflin wax oxidates (B and C), however, showed no ability as fuel stabilizers.

The additive of the invention was also tested in a base fuel having a somewhat higher percentage of a cracked component therein. The base fuel in this case consisted of 20 vol. percent of an acid-treated heavy kerosine distillate having a API gravity below '42 derived from asphalt base crude and 80 vol. percent of a fluid cracked light cycle gas oil. Test results on this fuel blend are as follows:

Gravity, API 36.7 Flash, P.M. F. 154 Viscosity, S.U. 100 F. 33.2 Color, ASTM L2 /2 Pour, F. ---20 Car. res. (10% btms.) 0.07 Corr. cu. strip at 122 F. Neg. 1 Sulfur, wt. percent 0.31 Ash, wt. percent -1 None Cetane No. 46.4 Aromatics, vol. percent 2.3 Olefins, wt. percent 3 Distillation, -F.:

I.B.P. 3'72 50% 474 E.P. 602

Samples of this fuel containing a high ester content,

6 vented containers kept in the dark for various periods of time and at various temperatures as follows:

(A) 1 month at 130 F. (B) 3 months at 110 F. (C) 3 months at room temperature Visual observations of the deposits formed during storage are presented in the following table:

TABLE IV Observation of storage deposits Three months at- One month at 130 F.

110 F. room temp.

Base fuel Base fuel 12 lbs of Oxidate A/1,000 bbls.

medium..

s1ight-medium.. very slightslight. very slight very slight.

The samples stored at 110 F. were subjected to testing in the oronite filter test which consisted of vigorously shaking a 150 ml. sample of the fuel to be tested with 25 ml. of distilled water for 15 to 20 seconds. The resulting mixture was filtered under vacuum through a No. 1 Whatman filter paper disc. The filter discs were retained for visual observation and comparison of the discoloration due to retained sediment. The samples stored at 130 F., as well as those stored at 110 F., were tested using the previously described basic .deposits determination test which difilered from the oronite filter test in that the sample was notshaken with water prior to filtering. The accelerated filter paper deposit test and oronite filter test were also used to test the fuel composition before storing.

The results of these tests which show the superiority of a fuel containing 12 lbs. of the high ester content, high viscosity petrolatum oXid'ate (oxidate A) per thousand barrels, with respect to stability, are given in the following tables:

TABLE V v Oronite filter test Storage Sample 7 Deposits Time, Temp., mo. F.

Base fuel -f Before storage slight. Base fuel Oxidate A-.." Before storage very slight. Base fuel mediumheavy. Base fuel Oxidate A 3 110 slight.

TABLE VI Accelerated filter paper deposit test Storage Sample Deposits Time Temp.

Base fuel Before storage .heavy. Base fuel Oxidate A Before storage slight.

TABLE VII Basic deposit determination test Storage 7 Sample Deposits Time, Temp., mo. F.

1 heav I 1 130 very slight. fu .4; 3 110 heavy. Base fuel Oxidate A '3 '110 slight.

The. above tables again amply demonstrate the dispersant quality of, the oxidate additives. of. this invention under various test and storage conditions.

Another test procedure used to demonstrate the effectiveness of the fuel composition of theinvention was the Enjay accelerated filter plugging test which has recently been widely publicized as an excellentmethod. for determining fuel stability. The Enjay filter plugging test consists of aging 4.5 gal. of the fuel composition to be evaluated in a steam chest for 16 hours with the fuel temperature raised from 77 F. to 235 F. at a specified rate. The fuel is then cooled to about 72 F. within 4 hours. and the filter plugging characteristics determined by' filtering 12 liters at a constant rate through a woven felt pad which was previously rinsed with n-heptane, dried and weighed. As deposits accumulate on the pad, the pressure drop across the pad increases. After the 12 liters of sample fuel have been filtered, a record is made of the final pressure drop, the weight of sediment of the pad, and the appearance of the pad. These values are expressed as demerit ratings and averaged to obtain an over-all accelerated filter plugging demerit rating. The demerit rating range runs from zero to ten where zero means a perfect pad with no discoloration and no appreciable pressure drop, and where ten means a very badly discolored pad with high weight increase and extreme pressure drop.

The following table shows the results. of the Enjay accelerated filter plugging test on the fuel compositions of, the invention and similar fuel compositions for comparison. The base fuel was that described as used in Tables IV, V, VI, and VII.

following table shows the, results of the quickie; corrosion test on the fuel composition of the invention in comparison with the. base fuel. The base fuel used in this test was that described in connection with the test results shown in Table I.

The above table shows that the oxidate of the invention provides. excellent rust protection in middle distillate fuels as compared to a known oxidate rust inhibitor (oxidate B).

As previously stated, included within the scope. of this invention are middle distillate fuel compositions containing the. specific high ester content, high viscosity petrolatum oxidate of this invention in combination with an amine metal deactivating compound such as the preferred disalicylal propylenediamine. The following table sets forth the results of deposits tests of fuels containing the additive combination of the invention. The test used was the basic deposit determination test previously described. The test samples were stored in dark vented TABLE VIII Demerlt Ratings FuelSample Appearance Weight Pressure Over-all Average Base iuel, 1st run 9 6 5 6. 7 Base fuel, 2nd run 9;; 7 3 6- 6 5 Base Fue1+12 lbs. of Oxldate A per 1,000 bbl s, of

fuel, 1st run 1 0 0 0- 3 Base Fuel+12 lbs. of Oxidate A per 1,000 bbls. of fuel,

2nd run 7 V 1 1 Q 0. 7. o 5 Base Fuel+12 lbs. of Oxidate B per 1,000 bbls. of fuel,

1st run- 6 5 1 4. 0 Base Fne1+12 lbs. of Oxidate B per 1,000 bbls. of fuel,

2nd run v 5 2 3 Base Fuel-H2 lbs. of Oxidate B per 1,000 bbls. of fuel,

3rd run 4 6 2 4. 0 4 1 The results in this test give added proof of the excellent fuel stability shown to be produced by the high ester content, high viscosity petrolatum oxidate of the invention in the previously described stability tests;

The high ester content high viscosity petrolatum oxidate of the invention, similar to wax oxidates, is an excellent anti-corrosive in lubricating oil which is disclosed in US. Patent No. 2,705 ,241. Its anti-corrosive property in'middle distillate fuels was demonstrated by the results of a slightly modified quickie corrosion test. The modified quickie corrosion test. consisted. of contacting a polished steel strip with 115 ml. of the test fuel composition in a tall 4 oz. bottle. The strip and test fuelj were allowed to stand for 15 minutes before 20 ml..of the test. fuel were removed and replaced by 20 ml. of distilled water. The bottle was then shaken for 15 seconds in a horizontal position, given a short swirl to sweep the large water drops from the strip and placed upright. Readings of the percentage of rust on the front and back of the strips were made after 3 hours at 120 F., and after anadditional 24 hours at room temperature. The corrosion readings, of the strip of steel in the fuel phase were expressed as percent of the surface of'the strip covered by rust. The

containers for 3 months at F. They werevi'gorous- 1y shaken prior to testing in orderto obtain a representative test sample. The base fuel used in these tests was that described in connection with the testing of the fuel compositions, the results of which are shown in Tables IV, V, VI, and VII.

The above table shows the ability of a combination of petrolatum oxidate and disalicylal propylenediamine to stabilize the fuel. The'combination is somewhat more .efiective, thanthe petrolatum oxidate alone alt ough there 9 is apparently no appreciable stability produced by the disalicylal propylenediamine alone. Further, the combination produces a more color stable fuel than the fuel composition containing only the oxidate of the invention.

Freezing pt., F. Below ---76 Smoke pt., mm. 24 Sulfur, percent 0.023 Mercaptan sulfur, wt. percent 0.002

The following table shows the results of tests which Aromatics, vol. percent 11.0 also demonstrate the superior stabilizing effect on a middle Olefins, wt. percent 1.0 253 513 5 52 ggy zgggfigg g fif gii gg z g z The thermal stability additive of the invention was cut back to facilitate handling by blending by wt. of the gh g g g g g ti i g? 2 i ggi i gi gg high ester content, highviscosity petrolatum oxidate with d d f by wt. of naphthemc petroleum distillate showing the pro uct pro uce e o owing resu ts. following test results:

o 2 2 E g: Gravity, API 0 34.4 viscosm; gab F 35 0 V1se0S1ty,SSU t 100 8 Color 15 Fla h, C.T., F. 165 Pour Sulfur, percent 0.082 Car. res. (10% btms.) 0.06 fi i izig stnl; 22: g Aromatics, vol. percent 19 u w Pe c 20 Olefins, wt. percent 2 Ash, wt. percent 0.003 0 Cetane No 50 6 Distillation, F..

I.B.P. 384 Aromatics, vol. percent 19 10 418 Olefins, wt. percent 4 50 462 Distillation, F.:

I.B.P. 404 BR 538 0 The amount of the additive of the inventlon, for convenience termed oxidate A, was given for the active in- .0 {on jected to vented dark storage for 3 months at room temg zg g g g g i i E 83 5 i fi 332g;

fz gs g'g g z gg i gggg gzfi z fgi gigpii prior ture of 400 F. and a fuel flow of 6 lbs./hr. forS hours.

TABLE XI TABLE XII S m 19 De as"; CFR fuel coker test a p Forn iation Pressurebuild- Base mp] medium- Run Fuel Sample up iagrgss fllgser, Base fuel-H2 lbs/1,000 bbls. of OxidateA slight. 40 agi; Base inel+12 lbs. of Oxidate A per 1,000 bbls. and 2 lbs./ very slight.

1,000 bbls. of disalleylal propylenedlamlne.

; Base fuel fi Again, it is obvious from the above table that the coma an 6. 70 a i of the invention is an exceptionally good fuel 12 11,541,000 of 81% stablllzel. Oxidate A.

To demonstrate the exceptional ability of the high ester 2: 8:58 content, high viscosity petrolatum oxidate of the inven- R dn 0.05 tion to improve the thermal stability of jet fuels, the CFR fuel coker test was used. This test comprises utilizing an apparatus Specifically designed for measuring high Current commerical specifications designate 12 niches temperature stability of jet fuels. It mainly consists of a of .mercury as the allowable Pressure bufld'up fuel storage zone, pump means to carry the fuel through Oxldate A exerts an unexpfacted Influence on the l a flow meter, a preheater, filtering means, a needle valve to lower the pllessure across the filter m this and to the drain. The test is run by adjustment of a 6:; an ifgz' g t d th fu 1 pressure regulator in the system, fuel flow, and the temer a f {nay ig 6 1 peratures of the preheater and filter assembly. The duraposmon o i mvelmon W1 out p i tion of the test is governed by a limiting pressure diftherpto Addliwes l' suppress deposlt i i p ferential of 25 inches of mercury across the filter or an conluncnon with the hlgh ester content high vlscoslty arbitrary time limit of 300 minutes petrolatum oxidate may at times be extremely useful.

The jet fuel which is presently being used in the greatest F exfunpleha.copolymer 2 2 f i P amounts by'the military and certain commercial aircraft mg ong C 31-11 compoun aving equl S ant reactwe is the IP-4 type This fuel must meet the requirements groups A pamcuhir compo-11nd 1s a copolymer of lmiryl MIL F 5624 methacrylate and diethylaminoethyl methacrylate WhlCh,

The base fuel u'sed in this test was a fuel Showing when mcorporated in a fuel, reacts with nitrogen, sulfur the followin test results which meet the above military 05 and oxygenated compounds to prevent Sludgmg' The r long chain structure enables the copolymer to stay in clmremen solution in the fuel. Gravity, API 50.1 Still other additives, for example, metal petroleum sul- Distillation, F.: fonates, either basic, neutral, or combinations thereof,

I.B.P. 140 are sometimes advantageously incorporated in the fuel 20% 230 compositions of this invention as additional stabilizers 50% 303 or dispersants.

90% 447 Obviously, many modifications and variations of the in- ER 500 vention, as hereinbefore set forth, may be made without Aniline pt., F. 127.9 departing from the spirit and scope thereof, and, therefore, only suchlimitations should be imposed cated in the appended claims. i 1

We claim: Y

1. A hydrocarbon fuel boiling within the range of about 100 to 750 F. containing, from 2 to 30 pounds per thousand barrels of apetrolatum oxidate characterized by a ratio of neut. No. to sap. No. below about 0.25 and an SUS viscosity at 210 F. of at least about 1,500 to 20,000, said amount being suificient to disperse deposits in the fuel.

2. A hydrocarbon fuel composition as described in claim 1 wherein the SUS viscosity at 210 F. of the oxidate ranges from about 2,500 to 12,000.

3. A hydrocarbon fuel. as described in claim 2 wherein the amount rangesfrom .about 5 to. 20 poundsv per thousandbarrels of fuel. 7

'4. A. hydrocarbon fuel boiling withinthe range of from 100 to 750 F. containing from 5 to 20 pounds per thousand barrels of. a petrolaturn oxidate having a maximum neut. No. of 35, sap. No. range of from 100, to 155, a neut. No. to sap. No. ratio of below about 0.25 and an SUS viscosity at 210? F. of 2,500 to.12,000.

5. A hydrocarbon fuelboiling Within the range of from 100 to 750 F..containing from 2 to 30 pounds per thousand barrels of. a petrolatum oxidate characterized by a as are indi-v 1'2 neut; No. to sap. No. ratio of below 0.25 and an SUS viscosity at 210 F., of from 1,500 to 20,000, andfrom 0.5 to 10 pounds per thousand barrels of a Schifis base reaction product of 1' mole of an aliphatic polyamine at least two primary amino groups attached to dilferent carbon atoms of the same open chain with at least 2 moles V of an aromatic aldehyde.

6. A hydrocarbon fuel as described in claim 5 wherein the Schifis base reactionproduct is disalicylal propylenediamine in an amount between 1 and 5 pounds per thousand barrels of fuel.

References Cited in the file of this patent UNITED STATES PATENTS Patent should read as correc UNITED STATES PATENT OFFICE CERTIFICATE OF 'QORRECTEON Patent No; 234M876 Maurice E.a Stanley et al.0

s in the-printed specification tion and that the said Letters June .21 1960 It is hereby certified that error appear of the above numbered patent requiring correc ted below. Column l2. line l after "polyamine" insert having 5 Signed and sealed this 8th day of November 1960a (SEAL) Attest:

ROBERT C. WATSON KARL H. AXLINE Attesting Oflice r Commissioner of Patents

Claims (1)

1. A HYDROCARBON FUEL BOILING WITHIN THE RANGE OF ABOUT 100 TO 750*F. CONTAINING FROM 2 TO 30 POUNDS PER THOUSAND BARRELS OF A PETROLATUM OXIDATE CHARACTERIZED BY A RATIO OF NEUT. NO. TO SAP. NO. BELOW ABOUT 0.25 AND AN SUS VISCOSITY AT 210*F. OF AT LEAST ABOUT 1,500 TO 20,000, SAID AMOUNT BEING SUFFICIENT TO DISPERSE DEPOSITS IN THE FUEL.