US3542531A - Petroleum distillate fuels gelled with copolymers of ethylene - Google Patents

Description

United States Patent 3,542,531 PETROLEUM DISTILLATE FUELS GELLED WITH COPOLYMERS 0F ETHYLENE Gordon D. Hiatt and Oliver W. Kaul, Rochester, N.Y.,

assignors to Eastman Kodak Company, Rochester, N.Y.,

a corporation of New Jersey No Drawing. Filed May 1, 1968, Ser. No. 725,903

Int. Cl. C101 7/02 US. Cl. 44--7 Claims ABSTRACT OF THE DISCLOSURE The present invention provides petroleum distillate fuel compositions comprising a petroleum distillate fuel having a gelling agent selected from the group consisting of ethylene-ethylacrylate, and ethylene-vinyl acetate copolymers dispersed therein, which compositions are gelled at room temperature and liquid at elevated temperatures of about 55 C. The invention further provides a method for producing the above-described petroleum distillate fuel compositions; comprising the steps of: (1) dispersing the above-described gelling agents in the petroleum distillate fuel, (2) warming the resulting mixture at elevated temperatures to form a gellable fuel dispersion, and (3) cooling the fuel dispersion.

The present invention relates to gelled petroleum distillate fuel oils and to a method of producing the same.

In the practical use of fuel oil, it is desirable in some cases for safety reasons to be able to store it in a solid form. This is particularly true, for example, in th case of aviation jet fuel which is utilized in both military and civilian aircraft applications. The rupturing of fuel tanks in jet aircraft in crashes during landing and take-off and the resulting spreading of the highly flammable fuel around the aircraft, into the passenger compartment and over surrounding dwellings and service structures has cost numerous lives which might have been saved had the fuel remained solid or gelled and confined and hence, less subject to the spreading of fire. Hence, the development of a solid or semisolid fuel which does not flow except under certain extraordinary environmental conditions has been and continues to be an important problem.

It is, therefore, an object of the present invention to provide a fuel composition for jet aircraft which is a gel or nonflowing semisolid under normal storage condi tions, but which is readily convertible to a free-flowing conventional fuel under easily reproducible, but atypical conditions of elevated temperatures.

According to the present invention, there is provided a petroleum distillate fuel composition comprising:

(a) from about 75 to about 95 weight percent of a petroleum distillate fuel having a boiling point of from about 250 to about 750 F.; and

(b) from about 5 to about 25 weight percent of a gelling agent selected from the group consisting of:

(l) ethylene-ethylacrylate copolymers consisting essentially of from about 15 to about 25 weight percent of ethylacrylate and the remainder being ethylene, and

(2) ethylene-vinyl acetate copolymers consisting essentially of from about 15 to about 25 weight percent of vinyl acetate with the remainder being ethylene.

The invention further provides a method for preparing the above-described petroleum distillate fuel compositions which method comprises the steps of:

(a) dispersing a gelling agent of the typ described above in the petroleum distillate fuel at a temperature of from about 110 to about 150 F., thus forming a petroleum distillate fuel dispersion in liquid or fluid form, and

3,542,531 Patented Nov. 24, 1970 ice (b) subsequently cooling the petroleum distillate fuel dispersion to a temperature below about 100 F.

The petroleum distillate fuels in which the gelling agents may be used to produce the gelled compositions which will be described in more detail below include aviation turbo-jet fuels and kerosen es suitable for use in jet engines. Such aviation turbo-jet fuels normally boil between about 250 and about 550 F. and are used in both military and civilian aircraft. Kerosenes suitable for treatment in accordance with thi invention will normally have boiling points of between about 300 and 750 F. and are generally referred to as No. l and No. 2 fuel oils.

Apparently the particular manner in which the gelling agents of this invention are manufactured has no influence on their peculiarly valuble gelling properties. All that is necessary, insofar as the successful practice of the present invention is concerned, is that the copolymeric gelling agents be polymerized to an extent sufiicient to make them solid (i.e., nonliquid) at about 25 C. Thus the copolymeric gelling agents of this invention should generally have a melt index of at least about 1. Methods for manufacturing the copolymeric gelling agents of this invention are well known in the art and need not be detailed herein.

EXAMPLE Ten thousand parts of JP-4 jet fuel are warmed carefully to a temperature of 140 F. Into this Warm jet fuel are poured slowly and with tirring, one thousand parts of a powdered ethylene/ethyl acrylate copolymer having a melt index of about 12 and containing 19.5 weight percent of ethyl acrylate. The resulting mixture is then stirred until a smooth solution is obtained while maintaining a temperature of 140-150 F. Upon cooling to ambient room temperature, the mixture is observed to gel to such an extent that it cannot be simply poured readily from an inverted open container.

This gelled fuel in an aircraft fuel tank may be heated locally (near the fuel outlet of the tank) as the fuel is needed for the engines. Other effective gelling agents such as E/VA copolymers and high melting parafiins can also be present in the gelled fuel compositions of this invention. In a manner similar to that of the foregoing example, any of the gelled fuel compositions of this invention can be manufactured.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit :and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. A gellable petroleum distillate fuel composition comprising:

(a) from about to about 95 weight percent of a petroleum distillate fuel having a boiling point of from about 250 to about 750 F.; and

(b) from about 5 to about 25 weight percent of a gelling agent selected from the group consisting of (l) ethylene-ethyl acrylate copolymers consisting essentially of from about 15 to about 25 weight percent of ethyl acrylate and from about 75 to about weight percent of ethylene; and (2) ethylene-vinylacetate copolymers consisting essentially of from about 15 to about 25 weight percent of vinyl acetate and from about 75 to about 85 weight percent of ethylene and (3) mixtures thereof.

2. A gellable petroleum distillate fuel composition as in claim 1 wherein said gelling agent is an ethylene/ethyl acrylate copolymer.

3. A gellable petroleum distillate fuel composition as in claim 1, wherein said gelling agent is an ethylene/vinyl acetate copolymer.

4. A gellable petroleum distillate fuel composition as in claim 1 wherein said fuel is jet fuel boiling within the range of from about 250 F. and about 550 F.

5. A method for producing a gelled petroleum distillate fuel comprising the steps of (a) dispersing from about 5 to about 25 weight percent of a gelling agent selected from the group consisting of 1) ethylene-ethylacrylate copolymers' sentially of from about to about Weight percent of vinyl acetate and from about to about weight percent of ethylene, in a petroleum distillate fuel having a boiling point of from about 250 to about 750 F.;

4 (b) warming the resulting dispersion at a temperature of from about to about F. to form a petroleum distillate fuel dispersion; and (c) cooling said petroleum distillate fuel dispersion to a temperature below about 100 F.

References Cited UNITED STATES PATENTS 3,084,033 4/ 1963 Kelly et a1. 44-7 3,219,619 11/1965 Dickerson 447 3,232,720 7/1966 Kepple 44-7 3,232,721 2/1966 Coyner et a1. 44--7 BENJAMIN R. PADGETT, Primary Examiner US. Cl. X.R. 149109