US 2892694 A
Description (OCR text may contain errors)
I eel -t ns. or. 52-.5
United States Patent PROCESS FOR THE 0F EMULSION FUELS Lloyd E. Weeks, Union, Ohio, .assignor to Monsanto Ch ca C mpany, .S ou s, Mo, a co p r tio o Delaware t No Drawing. Application May '22,, 1956 ri i 586, 9 r
The present invention relates to a process for the pro.-
.duction ,of -,an improved motor 'fuel suitable for -.use in jet and reciprocating engines, especially for aircraft use.
An object of the invention is the provision of emulsion fuels which can be easily prepared as aqueous emulsions,
utilizing water .of various andsundry qualities, and which when prepared are for all practical purposes perfectly stable in such form. It is a further object to improve the production of the said emulsions :by the provision of concentrates which need onlybe mixed with water for use as aircraft fuel.
The use of water-emulsified motor fuel is, of course,
fuels, however, required relatively pure water, usually water which had been purified by removal .of all or the major part of its contained hardness-forming salts. Unless these precautions were observed, the fuel emulsions formed therewith exhibited a pronounced tendency to separate into two phases, rendering such fuels unusable.
The present invention relates to an improved method for the production of fuel-emulsifier concentrates which can be mixed with water to provide emulsions which, for all practical purposes, are of a permanent nature. Moreover, the emulsion can be made by employing any quality of water available, provided, of course, that it is free of suspended solids, without the necessity of softening or otherwise treating said water. It has been found that the preparation of the desired emulsion fuels may be improved by the direct production of the essential emulsifying agent in the mixture of hydrocarbons boiling in the motor fuel boiling range, which mixture serves as the hydrocarbon source in the final emulsion fuel. Such solution of the emulsifying agent in the hydrocarbon mixture is suitable for direct addition with water to form the emulsion fuel. It has been found that this improvement obviates the necessity for the prior art method of the external production of the emulsifying agent in alcohol followed by filtration and evaporation of alcohol preliminary to the formation of a solution of the said emulsifying agent in the hydrocarbon fuel.
The hydrocarbon motor fuel employed as one of the constituents of the present emulsion may be a paraflinic or naphthenic type hydrocarbon boiling in the motor fuel boiling range. Kerosene is one of the fuels contemplated in the present invention. The present fuels are generally characterized by possessing an extremely low pour point. A typical hydrocarbon fuel of this type as used for jet engines is designated as JP-4 (Specification Mil-F 5624A) consists of a low vapor pressure liquid made from. a mixture of gasoline and kerosene.
Typical test data for a jet engine fuel are the following:
10% evaporated point, max. F 250 End point, max. F-.. 550 Freezing point, max. F 76 Specific gravity (60/60) max. M 0.825 Specific gravity (60/60) min. 0.747 Aromatics, percent by vol. max 25.0
2,892,694 Patented June 30, 1959 2 Bromine No. max. 30.0 Heating value B.t.u./lb. min. 18,400
For reciprocating engines the conventional type aircraft gasoline may be employed on the fuel component. The water employed in the preparation of the present fuel emulsion need not be distilled or deionized or otherwise specifically purified, and, accordingly, may contain the naturally occurring soluble salts, such as the carbonates, ch o i and su of cal um a es um n sodi mln general, the present invention contemplates the P p o o emulsion M1 y a emica react on 'wnducte in th hy o a bo u l as t o em .medium f (1) a al y -s lfoph halat and a basic ompou d s e d o h ou nsi t n of monia, amines and alkylolamines having from 1 l9 ,5 carbon atoms. The reaction may be carried out by addins e the o e o co p n n s to th o e in he hydrocarbon solution The preferred embodiment of the present invention contemplates the preparation of emulsion fuels by dissolving an alkyl-4-sulfophthalate, in which the two .alliyl radicals have from 6 to 12 carbon atoms in a motor fuel hydrocarbon fraction, and thereafter forming a salt by neutralizing the said solution. This is done by adding a suflicjent uantity of a basic compound selected from well understood in the art. The Preparation of such h IOHjP QQ li g 0f amm i in d .a k p amines having from 1 to 5 carbon atoms, until the soluion ha 1a PH in e range of 7 to 9. Th em e a u e s n t r t ca in the p ent p oce s- ,E amp s o e ba ic compo nds on mpla cl dea moh methy amines, ethyl amines, propyl amines, butyl amines, for
e a ple-mon and tr -bu y la ine en amines, ethanolamines, propanolamines and butanolamines employed as the compounds per se or as solutions in water or an organic solvent such as the above hydrocarbon fraction. The amount of the alkyl-4-sulfophthalate dissolved in the hydrocarbon fuel is from 10% to by weight relative to the fuel.
The above combinations of fuel together with the emulsifying component are diluted with water in order to obtain the emulsion fuel. The proportion of water thus employed may vary widely, such as by the use of from 8% to 50% by weight of the said hydrocarbon and emulsifier combination together with 92% to 50% by weight of water. The proportion of the said emulsifying com ponent, i.e., the basic salt of the alkyl-4-sulfophthalate present in the hydrocarbon fuel may vary from 0.5% to 25% by weight based on the weight of the hydrocarbon, with a range of emulsifier from 5% to 15% by Weight being preferred.
The preferred emulsifying compound of the above group is butyl ammonium hexyl-4-sulfophthalate. The preparation of the combination of the hydrocarbon fuel and butyl ammonium hexyl-4-sulfophthalate is shown in the following example.
Example 1 A -gallon, glass-lined reactor was charged with 18 pounds of n-butyl amine, together with 86.5 lbs. of jet aircraft fuel. The temperature was maintained at 40 C. by circulating cooled water through the jacket of the reactor. Dihexyl-4-sulfophthalate (94 pounds) was then added at a rate such that the reactor charge temperature did not exceed 40 C. During this stage the reaction mixture was kept acid by controlling the rate of addition of n-butylamine. The total amount of amine employed in entire reaction was 41.9 pounds. The final pH value of the solution was in the range of 7 to 9.
The solution of butyl ammonium hexyl-4-sulfophthalate in the hydrocarbon fuel provided a concentrate which was diluted with water for use as an emulsion fuel.
Example 2 above were placed in Nessler tubes and observed over a period of 24 hours. It was noted that no separation of phases occurred either in the fuel mixture made of water of zero hardness or with water of 1,000 p.p.m. hardness.
The emulsion stability test employed in the above example is a modification of the test described in Military Specifications I-l1425 and I-10917 (QMC).
In general, in carrying out the process of the present invention, an emulsion is prepared using conventional stirring procedures to mix water with the above-described concentrate of hydrocarbon fuel and emulsifier. No special equipment such as homogenizers or colloid mills is required. All that is necessary is to stir the above combination and water together by means of a conventional propeller-type stirrer.
What is claimed is:
1. A process for the preparation of an emulsion fuel concentrate which comprises dissolving dihexyl-4-sulfophthalate in a motor fuel hydrocarbon fraction in the concentration of from 10% to 80% of the said dihexyl-4- sulfophthalate, and neutralizing the said solution by adding a sufl'icient quantity of butylamine until the solution has a pH in the range of from 7 to 9.
2. A process for the preparation of an emulsion fuel v 4 which comprises dissolving dihexyl-4-sulfophthalate in motor fuel hydrocarbon fraction in the concentration of from 10% to 80% of the said dihexyl-4-sulfophthalate, and neutralizing the said solution by adding a suflicient quantity of butylamine, until the solution has a pH of from 7 to 9, and thereafter combining the said mixture with water in the proportion of from to 92% by weight of water referred to the hydrocarbon-water combination and agitating to form an emulsion.
3. A process for the preparation of an emulsion fuel concentrate which comprises dissolving a dialkyl-4-sulfophthalate, in which the alkyl radicals have from 6 to 12 carbon atoms, in a motor fuel hydrocarbon fraction in the concentration of from 10% to of the said dihexyl-4-sulfophthalate, and neutralizing the said solution by adding a suflicientquantity of a basic compound selected from the group consisting of ammonia, lower alkyl amines and lower alkylolamines having from 1 to 5 carbon atoms, until the solution has a pH in the range of 7 to 9.
4. A process for the preparation of an emulsion fuel which comprises dissolving a dialkyl-4-sulfophthalate in which the alkyl radical has from 6 to 12 carbon atoms, in a motor fuel hydrocarbon fraction in the concentration of from 10% to 80% of the said dialkyl-4-sulfophthalate, and neutralizing the said solution by adding a suflicient quantity of a basic compound selected from the class consisting of ammonia, lower alkyl amines and lower alkylolamines having from 1 to 5 carbon atoms, until the solution has a pH in the range of 7 to 9, and thereafter combining the mixture with water in the proportion of from 50% to 92% by weight of water, referred to the hydrocarbon-water combination and agitating to form an emulsion.
No references cited.