US2296069A - Fuel for internal combustion engines - Google Patents

Description

Patented Sept. 15, 1942 FUEL FOR INTERNAL COMBUSTION ENGINES Guy w. Talbert, Summit, N. J., and Everett w. Blizzard, Kenmore, N. Y., assignors to Allied Chemical & Dye Corporation, a corporation of New York No Drawing. Application March 21, 1940, Serial No. 325,118

14 Claims.

This invention relates to a new fuel and to its use for the operation of internal combustion engmes.

It is well known commercial hydrocarbon fuels for internal combustion engines, for example gasoline, have the tendency to produce objectionable deposits of carbon and tarry matter within the internal combustion areas of the engines. The many objectionable effects of such deposits are also well known and numerous expedients have been proposed for preventing the deposition of carbon and g-u-mmy matter in internal combustion engines or for removing such deposits as have previously been formed in such engines.

We have now discovered hydrocarbon fuels containing small quantities of one or a mixture of higher alkyl aryl sulfonates have unexpected and much desired qualities as fuels for internal combustion engines. The fuels ofthis invention may be used in the same manner as the hydrocarbon fuels from which they are prepared; but, in comparison therewith, the engines operated on fuels containing the higher alkyl aryl sulfonates may be operated over longer periods of profitable, useful, operating time with little, if any, deposits of carbon or tarry matter in the combustion chambers of the engine and on the surfaces adjacent thereto. Moreover, .We have discovered that if an internal combustion engine which, by being operated on other fuels, has become fouled with carbon or tarry deposits is operated even for relatively short periods on our improved fuel compositions, there is an unexpected and desirable removal of such deposits from the fouled surfaces within the engine, such as the surfaces in the combustion chamber and those adjacent thereto. Such surfaces are cleaned and madesubstantially free from the'undesirable carbonaceous deposits.

Our invention comprises the novel fuels for internal combustion engines hereinafter described and the use of these fuels for the operation of such engines. The novel fuels of this invention comprise a hydrocarbon fuel containing a small amount of any higher alkyl aryl sulfonate in where R is an alkyl group which contains 20 to 30 carbon atoms joined carbon to carbon, A is a monoor dinuclear aromatic residue, n is an into a carbon atom of the aromatic nucleus or it may be indirectly linked to the aromatic nucleus through an atom or group of atoms X, for example, through an oxygen atom or one of the groups of atoms -NH--, NHCO, --CO, or -COO-. The aromatic residue A may be mononuclear, as for example, a residue derived from. benzene, toluene or phenol, or it may be bi-nuclear, as for example, a residue derived from naphthalene or diphenyl. In addition to the sulfonate group and the alkyl group represented by R, the aromatic residue represented by A may or may not contain one or more other substituents, for example, chlorine, hydroxy, alkyl, al-

koxy and carboxyl (in the free acid or salt form).

Of the alkyl aryl sulfonates described above which may be incorporated with a hydrocarbon fuel in accordance with this invention, we prefer to employ those compounds in which the aromatic nucleus is mononuclear and is directly linked to a saturated, branched, carbon chain alkyl group free from substituents. Preferably the sulfonate is in the form of a salt, which may contain either an inorganic or organic salt-forming radical. The aromatic nucleus of the sulfonate preferably is free from substituents other than the higher alkyl and sul-fonate groups.

- Among the more easily procured salts are the ammonium, alkali metal and alkaline earth metal salts and those salts in which the acidic sulfonate group is neutralized by the more common organic bases such as mono-, dior triethanolamine, pyridine, ethylene diamine, amylamines and triethylene tetramine. Preferred compounds are those prepared by the processes disclosed in U. S. patent application of Lawrence H. Flett, Serial No. 186,733, filed January 24. 1938, in which the alkyl groups are hydrocarbon radicals containing 20 to 30 carbon atoms, preferably derived from a petroleum hydrocarbon mixture, and are nuclear substituents.

l The sulfonates may be added to any hydrocarbon fuel such as light or heavy fuel oils, gasoline or kerosene. These fuels may also contain any of the usual aids and distinguishing constituents such as coloring matters, lubricants, antiknock agents, etc. The sulfonate content of the fuel may be varied over a relatively wide range but in all cases it represents but a minor addition to the fuel, for example not more than about 1 part by weight of the sulfonate per 1000 parts by weight of the fuel. We prefer to introduce the sulfonate into the hydrocarbon fuel in amount such that the resulting product contains from about 0.025 to about 1 part by weight of the sulfonate per 1000 parts by weight of the fuel.

Commercial hydrocarbon fuels ordinarily contain very small proportions of water. For example, gasoline at 15 C. will dissolve about 0.04 part of water per 1000 parts of gasoline. The usual methods of producing the higher alkyl aryl sulfonates added to hydrocarbon fuels in accordance with this invention result in a product containing some water. The addition of these sulfonates to a hydrocarbon fuel will result in an increase in the water content of the fuel.

Even though the amount of water thus introduced into the fuel is greater than that soluble in the fuel itself, the sulfonates will emulsify the water so as to keep it in fine suspension in the fuel and thus prevent water settling out and exercising its known deleterious effects when a fuel containing more water than is soluble therein is supplied to an internal combustion engine. The presence of the higher alkyl aryl sulfonates permits of incorporating in the fuel relatively large amounts of water if this should be desired.

We prefer, however, the fuels of this invention contain less than 0.2 part water per 1000 parts fuel.

The following examples are illustrative of our invention:

Example I.A preparation containing a mixture of the sodium salts of sulfonated higher alkyl benzenes made by the process described in Example '7 of U. S. Patent application of Lawrence H. Flett, Serial No. 186,733, filed January 24, 1938, is dissolved in commercial gasoline. This sulfonate material has substantially the following composition by weight:

Percent Sodium alkyl benzene sulfonates, of which the alkyl groups contain an average of about 23 to 24 carbon atoms 11.5 White oil (a refined petroleum distillate which is a mixture of substantially saturated hydrocarbons having a molecular content of 20 to 28 carbon atoms and an average molecular content of about 23 to 24 carbon atoms) 14 Water 14 Stoddard solvent 60.5

One gallon of commercial gasoline is mixed with 13.5 ounces (by weight) of the above sulfonate product. The white oil and Stoddard solvent in the sulfonate product are hydrocarbon compounds which hold the alkyl aryl sulfonate and the water in solution while themselves being wholly soluble in hydrocarbon fuels. Accordingly, this sulfonate product upon being added to the hydrocarbon fuel (in this case gasoline) immediately blends therewith to form a perfectly uniform composition. The resulting solution is added to commercial gasoline in the proportions of 4 fluid ounces of the solution for every 5 gallons of gasoline to form a novel fuel composition of this invention. That fuel contains the following proportions of added constitutents expressed in parts of the added constituents in 1000.parts of the fuel. weight:

In both cases the parts are by This gasoline-fuel was used to operate the engine of a tractor which had previously been operated on commercial gasoline. This engine was fouled internally with excessive deposits of carbon and gum, which had required the spark plugs to be cleaned frequently to permit the engine to operate. The fouled engine was operated for 10 consecutive daily periods of 8 hours each employing the above fuel containing sodium alkyl benzene sulfonates. At the end of this period of operation the engine head was removed and it was found the combustion chambers and adjacent surfaces, such as those of the spark plugs, valve heads and seats and the tops of the pistons, were substantially clean and free of carbon and tarry deposits.

The engine head was replaced and it was put into service for 4 consecutive daily periods of 8 hours each operating on the commercial gasoline used in preparing the above fuel composition of this invention. In this period of operation sufficient carbon and tarry matter accumulated in the engine to cause it to miss fire and to require cleaning two of its six spark plugs.

The above fuel composition of this invention was used for the operation of a farm tractor which was fouled with deposits of carbon by operation on other fuels. The tractor was operated on the fuel composition of this invention for 96 operating hours. During this period there was a very noticeable improvement in smoothness of operation. The engine gained considerably in power and in its output of power per unit of fuel consumed. Its pick-up when the rate of fuel supplied to the engine was increased, improved. At the end of this period the combustion chambers and adjacent passages of the engine were substantially free from all carbon and tarry deposits and retained only a very thin, easily removable, grayish powdery layer which easily rubbed off by the touch of a finger.

Example II.-The sodium alkyl benzene sulfonate material of Example I is dissolved in commercial gasoline in the proportions of one pound of the sulfonate material per gallon of gasoline. One fluid ounce of the resulting solution was added to every 5 gallons of a Diesel #3 oil. 1000 parts by weight of the resulting fuel, composition contained the following:

Parts by weight Sodium alkyl benzene sulfonates 0.025 Water. 0.031 White oil 0.031 Stoddard solvent 0.133

This fuel was used for operating a Diesel tractor engine which had previously been operated on regular Diesel oil and, because of excessive deposits of carbon in the engine, was operating very unsatisfactorily. The engine was operated for 26 days (about 16 hours per day) and during this period of operation there was a marked improvement in the performance of the engine. This improvement was evidenced by a very noticeable decrease of irregularity in its running, an improved response to accelerated rates of feed of fuel, and a gradual but distinct increase in power output. After this period of operation examination of the surfaces within and near the combustion chambers of the engine showed these surfaces had become relatively free from carbon deposits.

Example III.--A quantity of commercial lubricating oil-S. A. E. 30 (Gulf Lube) is fractionated in vacuo, and a fraction boiling from 175 C. at 2 mm; absolute mercury pressure to 230 C. at 2 mm. absolute mercury lpressure collected. The fraction is acid washed by mixing it, at about 20 to 25 C.,with one-fifth of its volume of 98% to 100% sulfuric acid, and agitating the acid mixture for 2 to 3 hours; thereafter the mixture is allowed to stratify by letting it stand for about one hour. The separated lower layer of acid is withdrawn from the upper layer of oil, which is a mixture of hydrocarbons with an average molecular weight of 338 (C24H5o). It has a specific gravity of 0.866/25" C.

The agitated oil is chlorinated at about 50 to about 60 C. with chlorine gas until the amount of organically combined chlorine in the chlorinated hydrocarbon, based on the average molecular weight, is about 131% of that which theoretically would be present if all the hydrocarbons in the mixture were monochlorinated. The specific gravity of the chlorinated hydrocarbon mixture at 25 .C. is 0.945.

300 parts of thevchlorinated hydrocarbon mixture thus obtained are added gradually to a wellagitated mixture of 150 parts of benzene and 21 parts of anhydrous aluminum chloride while maintaining the temperature of the mixture at about 20 to 30 C. The completed mixture is stirred for one hour at about 25 C. and for another hour at about 55 to 60 C., after which it is allowed to settle for about 16 hours. The

' mixture resolves itself into two layers: the lower tarry layer is discarded; the upper layer of oil,-

after being filtered through filter cel, is washed with 200 cos. of a 10% aqueous solution of sodium bisulfite. The washed oil is separated from the aqueous wash and partially distilled in vacuo (about 25 mm. of mercuryfpressure) until the vapor temperature above the distilland is about 100 C. The distillation removes water, unreacted benzol and lights from the distilland. The remaining distilland contains chiefly nuclearly alkylated benzene compounds wherein the alkyl group corresponds to the chlorhydrocarbons from which the mixture, was derived.

A mixture of 50 parts of the distilland of alkyl benzenes and 99 parts of sulfuric acid (98% to 100%), is agitated continuouslyfor about one hour, while the temperature of the mass is maintained at about 55 C. to about 60 C. The mass is then diluted with 45 parts of water, but the temperature of the mixture during dilution is maintained at about 50 C. Then 198 parts Stoddard Solvent are added, and the whole mass is thoroughly agitated for about one hour. Thereafter, the mixture is allowed to stand for about 16 hours, and the lower separated layer of acid is withdrawn and discarded. The upper layer of Stoddard Solvent solution is thoroughly mixed with enough 50% aqueous caustic soda to make the mass neutral or very faintly alkaline. Thereafter, 20 parts of water are added to the mixture. 'The emulsion is stabilized by addition of butyl Cellosolve and capryl alcohol in amounts such that every 280 grams of the product contains 3 cos. of butyl Cellosolve and 0.5 cc. of-

of solutions of alkyl benzene sulfonates in gasoline or other hydrocarbon solvents.

The product produced by the above procedure contains about 11% water and about 22.5% sodium alkyl benzene sulfonates in which the alkyl groups derived from the hydrocarbons of the "Gulf Lu contentof about 24 carbon atoms.

About 303 cos. of the sulfonate produced obtained as described (corresponding to 57.3 grams of mixed sodium alkyl benzene sulfonate) are added to 2540' cos. of commercial Gulf gasoline.

This gasoline solution is added to Gulf gasoline in the proportion of 4 fluid ounces'of the solution to five-gallons of Guli gasoline. The resulting fuel contained about 0.47 gram of the aforesaid mixedsodium alkyl benzene sulfonates per gallon of gasoline, corresponding to about 0.168 part sodium alkyl benzene sulfonate per 1000 parts gasoline.. About gallons of Gulf gasoline thus treated were consumed as fuel in an old Case tractor, during about 116 hours of actual operation. The tractor improved in starting and pulling. Frequent spark plug examination showed no signs of increased carbon deposits in the engine during the 116 hours of operation.

Throughout this specification, except where otherwise specifically designated, the quantities of materials are given in terms, of parts by weight.

We claim:

1. A hydrocarbon fuel for use in an internal combustion engine, said fuel containing a small amount of a higher alkyl aryl sulfonate in which the aromatic nucleus contains not more than'two nuclei and the higher alkyl substituent contains from 20 to 30 carbon atoms joined carbon to 3. A hydrocarbon fuel for use in an internal combustion engine, said fuel containing a small amount of an alkyl aromaticsulfonate in which the alkyl group contains 20 to 30 carbon atoms and corresponding in the free acid form with the formula R-X-A-(SOaHM wherein A is an aromatic residue, R is an alkyl group containing 20 to BO-carbon atoms, and which may be substituted by hydroxy, alkoxy, cycloalkyl, aryl or halogen, Xis a bond joining a carbon atom of the alkyl group R to a carbon atom of the aromatic nucleus A or is a linking atom or radical. and n is an integer.

4. A hydrocarbon fuel for use in an internal combustion engine, said fuel containing an alkyl aryl sulfonate in the proportions of about 0.025 to 1 part by weight of the sulfonate in 1000 parts by weight of said fuel, said sulfonate being one in which the aromatic nucleus is mononuclear and the alkyl substituent is a saturated, branched, carbon chain alkyl group containing 20 to 30 carbon atoms, is free from substituents and is directly linked to the aromatic nucleus.

5. A hydrocarbon fuel for use in an internal combustion engine, said fuel containing a small amount of a mixture of alkyl mononuclear aro oil have an average carbon r matic sodium sulfonates in which the alkyl groups are hydrocarbon radicals containing from 20 to 30 carbon atoms which are derived from a petroleum hydrocarbon mixture and are nuclear substituents.

6. A hydrocarbon fuel for use in an'internal combustion engine, said'fuel containing a small amount of a higher alkyl aryl sulfonate in which the aromatic nucleus contains not more than two nuclei and the higher alkyl substituent contains from 20 to 30 carbon atoms joined carbon to carbon, said fuel containing not more than 0.2 part by weight water per 1000 parts by weight fuel.

'7. A hydrocarbon fuel for use in an internal combustion engine, said fuel containing a small amount of a mixture of alkyl mononuclear aromatic sodium sulfonates in which the alkyl groups are hydrocarbon radicals containing from 20 to 30 carbon atoms which are derived from a pctroleum hydrocarbon mixture and are nuclear substituents, said fuel containing 0.025 to 1 part by weight of said sulfonates and not more than 0.2 part by weight water in 1000 parts by weight of the fuel.

8. In the operation of an internal combustion engine the improvement which comprises supplying as a fuel to said engine a liquid hydrocarbon fuel containing a small amount of a higher alkyl aryl sulfonate in which the aromatic nucleus contains not more than two nuclei and the-higher alkyl substituent contains from 20 to 30 carbon atoms joined carbon to carbon.

9. In the operation of an internal combustion engine the improvement which comprises supplying as a fuel to said engine a liquid hydrocarbon fuel containing an alkyl aryl sulfonate in the proportions of about 0.025 to 1 part by weight of the sulfonate in 1000 parts by weight of said fuel, said sulfonate being one in which the aromatic nucleus is mononuclear and the alkyl substituent is a saturated, branched, carbon chain alkyl group containing 20 to 30 carbon atoms, is free from substituents and is directly linked to the aromatic nucleus.

10. In the operation of an internal combustion engine the improvement which comprises supplying as a fuel to said engine a liquid hydrocarbon fuel containing a mixture of alkyl mononuclear aromatic sodium sulfonates in which the alkyl groups are hydrocarbon radicals containing from 20 to 30 carbon atoms which are derived from a petroleum hydrocarbon mixture and are said fuel containing 0.025

nuclear substituents, to 1 part by weight of said sulfonates and not more than 0.2 part by weight water in 1000 parts by weight of the fuel.

11. In the operation of an internal combustion engine the improvement which comprises supplying as a fuel to said engine a liquid hydrocarbon fuel containing a small amount of an alkyl aryl sulfonate in which the aromatic nucleus is mononuclear and the alkyl substituent is a saturated, branched, carbon chain alkyl group containing 20 to 30 carbon atoms, is directly linked to the aromatic nucleus.

12. In the operation of an internal combustion engine the improvement which comprises supplying as a fuel to said engine a liquid hydrocarbon fuel containing a small amount of an alkyl aromatic sulfonate in which the alkyl group contains 20 to 30 carbon atoms and corresponding in the free acid form with the formula wherein A is an aromatic residue, R is an alkyl group containing 20 to 30 carbon atoms, and which may be substituted by hydroxy, alkoxy, cycloalkyl, aryl or halogen. X is a bond joimng a carbon atom of the alkyl group R to a carbon atom of the aromatic nucleus atom or radical, and n is an integer.

13. In the operation of an internal combustion engine the improvement which comprises supplying as a fuel to said engine a liquid hydrocarbon fuel containing a small amount of a mixture of alkyl mononuclear aromatic sodium sulfonates in which the alkyl groups are hydrocarbon radicals containing from 20 to 30 carbon atoms which are derived from a petroleum hydrocarbon mixture and are nuclear substituents.

14. In the operation of an internal combustion engine the improvement which comprises supplying as a fuel to said engine a liquid hydrocarbon fuel containing a small amount of a higher alkyl aryl sulfonate in which the aromatic nucleus contains not more than two nuclei and the higher alkyl substituent contains from 20 to 30 carbon atoms joined carbon to carbon, said fuel containing not more than 0.2 part by weight water per 1000 parts by weight fuel.

GUY W. TALBERT. EVERET'I W. BLIZZARD.

is free from substituents and A or is a linking 4