US3481716A

US3481716A - Diesel fuel composition

Info

Publication number: US3481716A
Application number: US797346*A
Authority: US
Inventors: Adolph V Mrstik; Walter F Schoen; Frederick L Voelz
Original assignee: Sinclair Research Inc
Current assignee: Sinclair Research Inc
Priority date: 1969-01-23
Filing date: 1969-01-23
Publication date: 1969-12-02
Anticipated expiration: 1986-12-02

Description

United States Patent 3,481,716 DIESEL FUEL COMPOSITION Adolph V. Mrstik, Chicago Heights, Walter F. Schoen,

South Holland, and Frederick L. Voelz, Orland Park,

111., assignors to Sinclair Research, Inc., New York,

N.Y., a corporation of Delaware No Drawing. Continuation of application Ser. No. 723,555, Apr. 23, 1968. This application Jan. 23, 1969, Ser. No. 797,346

Int. Cl. C101 1/30, 1/14 U.S. Cl. 44-68 8 Claims ABSTRACT OF THE DISCLOSURE A diesel fuel composition for use in diesel engines adapted to have substantially reduced combustion deposits formed in the combustion chambers of the engine consisting essentially of a diesel hydrocarbon fuel and a diesel fuel-soluble metal salt of a phosphorus compound which reduces deposit formation having the formula:

R0 R0 SH This application is a continuation of application Ser. No. 723,555, filed Apr. 23, 1968, which, in turn, was a continuation-in-part of applications Ser. No. 418,917, filed Dec. 16, 1964 now abandoned and Ser. No. 419,578, filed Dec. 18, 1964 now abandoned.

The present invention is directed to diesel fuel compositions having reduced deposit-forming tendencies when burned in the presence of combustion air in the combustion chambers of compression-ignition engines.

A common problem associated with compression-ignition engines such as diesel engines is the excessive buildup of carbonaceous deposits in the combustion chambers of these engines, particularly when the engines are run under, idle or low load conditions, or when using the heavier diesel fuels such as the heavy straight run distillate fuel and straight run distillates mixed with catalytically cracked distillate fuels or residual fuels. These combustion chamber deposits interfere with normal flame propagation and cause loss of power and/0r inefficient engine operation.

It has now been found that a diesel fuel-soluble atomic number 27 to 30 metal salt of certain phosphorus compounds when added to hydrocarbon diesel fuels in small amounts reduces the amount of deposits formed in the combustion chambers of engines wherein such fuels are burned. The phosphorus compound, the atomic number 27 to 30 metal salts of which constitute the additives of the present invention, have the following formulae:

R0 OH R0 SH and I II

"ice

an aliphatic, aromatic or mixed aliphatic-aromatic radical and is preferably non-olefinic and non-acetylenic, i.e. having adjacent carbon atoms no closer than 1.40 A. The total number of carbon atoms in 'a molecule of the phosphorus compound is preferably up to about 30 or even 40 and the metal salt of the phosphorus compound is soluble .in the diesel fuels at least to the extent employed in this invention. The phosphorus compounds from which the metal salts, i.e. the cobalt, nickel, copper and Zinc salts, of the invention are made can be obtained by any method known to the art as, for instance, by reacting aliphatic, including cycloaliphatic, alcohols or aromatic hydroxy compounds such as phenols and naphthols with P 0 to form phosphoric acid esters (I) and with P S to form the dithiophosphoric acid esters II). Mixtures of aliphatic or aromatic hydroxy compounds can be employed in the reaction if desired and the compounds may be substituted with nondeleterious groups and can be saturated or unsaturated in the alphatic, including cycloaliphatic, chains. The preferred alcohols are alkanols, which can be straight or branched chain, and alkyl substituted phenols whose alkyl substituents contain a total of up to 18 carbon atoms, and preferably are lower alkyl, especially methyl. Illustrative of suitable alcohols are pentanol, butanol, octanol, isoctanol, 2- ethyl-heptanol, dodecanol, oleyl, octadecyl, tetradecyl alcohols, alcohols prepared by the 0x0 process, phenol, and alkylated phenols such as cresol, xylenol, ethyl phenol, diethyl phenol, propyl phenol, butyl phenol, dibutyl phenol, monoamyl phenol, diamyl phenol, octyl phenol, dioctyl phenol, decyl phenol, dodecyl phenol, tetradecyl phenol, hexadecyl phenol and octadecyl phenol.

The reaction of the alcohol and P 0 or P 8 to prepare the partial esters can be conducted by heating the reactants at temperatures of from about C. to about C. for a period of time sufficient to effect substantially complete reaction, usually about 1 to 15 hours. An inert solvent such as toluene, xylene or the like may be used to facilitate the reaction. A useful molar ratio of alcohol to P 0 or P S is about 3:1.

The ester products can be monoalkyl, dialkyl, monoaryl, or diaryl esters of phosphoric acid or dithiophosphoric acid, or any combination thereof. The mixed esters are often present, for instance, in a mole ratio of at least 25% of each, say about 60 to 40% monoester and 40 to 60% diester. The metal salt of the mixed esters can be prepared by directly reacting the mixed esters with a carbonate or acetate of a metal having an atomic number of 27 to 30. Alternatively, the sodium salt of the mixed esters can first be formed and then reacted with an aqueous or alcoholic solution of a chloride of the metal to produce the corresponding diesel fuel-soluble, metal salt of the present invention.

The hydrocarbon diesel fuels of the present invention can be the straight run distillate type diesel fuels or fuel blends containing in large part the straight run diesel fuels. Economy type fuels can be used and usually represent blends of straight run and catalytically cracked distillate stocks with the latter type frequently predominating. Other diesel fuels contemplated include residual oil stocks cut-back to appropriate viscosity levels by means of about 5% or more, usually about 40 to 60% distillate cutter stock composed of straight run and/or catalytically cracked components boiling in the diesel fuel range.

The amount of the additive of the invention incorporated into the diesel fuel may vary depending upon the specific type and grade of diesel fuel selected as well as the particular engine utilized, the power output at which the engine is run, etc., but will be suflicient to substantially reduce the combustion deposits formed in the combustion chambers of the engine. Generally, about 0.002 to 0.4 or even up to 0.8 millimole or milligram atom of metal, preferably 0.025 to 0.3 millimole or milligram atom, as the metal salt per gallon of diesel fuel are utilized. This often means that about 0.5 to 25 or 30 or more pounds of the metal salt is added, preferably about 4 to 10 pounds, per 1000 barrels of diesel fuel.

The following examples are included to further illustrate the invention.

EXAMPLE I A cobalt salt of mixed mono and diisodecyl phosphoric acid was prepared as follows:

Two moles of mixed, approximately 50:50 monoand di-isodecyl esters of phosphoric acid were reacted with a molar excess of cobaltous carbonate. The reaction was carried out at 75 C. for one hour. The reaction product was filtered, water-washed several times and refiltered. The resulting hydrocarbon solubles were dried to a constant weight. Product analyses showed 4.53 weight percent cobalt and 4.5 weight percent phosphorus.

The cobalt salt thus prepared was added to a petroleum diesel fuel in the amount of 21.4 pounds of additive per thousand barrels of diesel fuel. The diesel fuel to which the cobalt additive was added had the following inspections:

4 EXAMPLE II The nickel salt of mixed, approximately 50% monoand approximately 50% di-cresyl esters of phosphoric acid was prepared by reacting 2 moles of the mixed monoand di-cresyl esters with an excess of 2 moles of nickel carbonate at 8090 F. for 1 hour. (The esters were derived by reacting mixed cresols with P Upon completion of the reaction, the reaction mixture was filtered. The hydrocarbon solubles were water-washed several times, refiltered and the resulting nickel salt of mixed monoand di-cresyl esters of phosphoric acid was dried to constant weight. Elemental analysis of the additive showed: nickel 2.8%; phosphorus 2.7%.

Substantially the same results obtained by the cobalt salt in Example I above can also be obtained by adding 21.5 lbs. amounts of the thus-prepared nickel salt 'of mixed monoand di-cresyl esters of phosphoric acid per 1000 barrels of the diesel fuel of Example I.

EXAMPLE III The nickel salt of hexyldithiophosphoric acid ester was prepared as follows:

Four moles of hexanol were reacted with one mole P 8 to form mixed monoand di-hexyldithiophosphoric acid ester. A slight excess over one mole of nickel carbonate was reacted with each mole of the ester to form A I i 30.6 the nickel salt. The reactions were carried out at 80 C. Flash, PM, F 184 With the resulting product being filtered, water-Washed, Viscosity at 100 F., SUS 37.97 hydrocarbon-washed (benzene), then dried at 80 C. to Pour, F B-l0 30 constant weight. Sulfur, wt. percent 0.40 The addition of 21.4 lbs/1 000 barrels of the thus-pre- Ash, percent 0.0002 pared nickel salt to a diesel fuel having an API gravity of Cetane No. 40.5 30.6, a Cetane No. of 40.5 and having a distillation range IBP, F. 382 f P 382 to EP 676 F., provides a composition hav- 10% evap., F 420 g reduced combustion deposit-forming tendencies. 50% evap., F 506 Diesel fuel compositions having similar characteristics 90% evap., F 612 can be obtained by adding to the diesel fuel of Example End point, F. 676 III the following additives in the designated amounts:

Additive #li iit l tl Cobalt salt of oetadecyldithiophosphorie acid" Copper salt of didodecyldithiophosphoric acid 20 VI Zn salt of dieicosyldithiophosphotic acid 22 The above fuel, without the cobalt organophosphate, was run in a GM Model 2-71 two stroke cycle diesel engine. The engine was run for hours at a constant speed, idle condition. After this test the head was removed and the deposits in the combustion chamber were examined. The deposits were tightly bound to the head, and weighed 2.5920 grams.

The engine was thoroughly cleaned, and a second test run was made on the same diesel fuel plus 21.4 pounds per 1000 barrels of the cobalt organophosphate. After 45 hours of constant speed, idle operation, the head of the engine was again removed and the deposits examined. This time the bonding between the head and the deposits Was loose, and the total deposit accumulated on the head was only 2.3615 grams, a reduction of 8.9 percent from the previous run.

The engine was again cleaned and reassembled, and the base fuel containing no additive was run for 45 hours at an idle condition, followed by a one-hour operation at full load. The engine was cleaned and the same cycle repeated with the fuel containing 21.4 pounds per 1000 barrels of the cobalt additive. Total deposit weight col lected on the head was 0.2545 gram without the additive, and 0.1387 gram with the additive, or a reduction of 45 percent as a result of the cobalt additive.

These four test runs show that the metal salts of the invention, when added in very low concentrations to diesel fuel, will reduce deposits accumulated in the combustion chambers of diesel engines.

on R0 SH wherein R is a hydrocarbon radical of up to about 30 carbon atoms on the average, and R is selected from the group consisting of hydrogen and R, said metal having an atomic number of 27 to 30 and being present in an amount sutficient to provide about 0.002 to 0.8 milligram atoms of metal per gallon of diesel fuel.

2. The composition of claim 1 wherein the amount of said metal is about 0.025 to 0.3 milligram atoms of metal per gallon of diesel fuel.

3. The composition of claim 1 wherein the metal salt is the cobalt salt of mixed monoand di-isodecyl esters of phosphoric acid.

4. The composition of claim 1 wherein the metal salt is the cobalt salt of mixed monoand di-isodecyl esters of dithiqph qsphoric acid.

6 5. The composition of claim 1 wherein the metal salt and the amount of said metal salt is about 0.025 to 0.3 is a salt of a phosphorus compound having the formula: milligram atoms of metal salt per gallon of diesel fuel.

8. The composition of claim 7 wherein the metal salt is the cobalt, salt of mixed monoand di-isodecyl esters 5 of dithiophosphoric acid.

O 0 References Cited and the amount of said metal salt is about 0.025 to 0.3 UNITED STATES PATENTS milligram atoms of metal salt per gallon of diesel fuel.

6. The composition of claim 5 wherein the metal salt 215 60542 7/1951 Bartleson et a1 44-68 is the cobalt salt of mixed monoand di-isodecyl esters 10 3,055,748 9/1962 Harfle 44 '69 ofphosphoric acid 3,055,925 9/1962 Hartle 44-69 7. The composition of claim 1 wherein the metal salt is 3,065,065 1/1962 Sutton et 44 69 a salt of a thiophosphorus compound having the formula: V DANIEL E. WYMAN, Primary Examiner 0 R SH Y. H. SMITH, Assistant Examiner US. Cl. X.R.