Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/146—Macromolecular compounds according to different macromolecular groups, mixtures thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F8/00—Chemical modification by after-treatment
  • C08F8/02—Alkylation
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/16—Hydrocarbons
  • C10L1/1625—Hydrocarbons macromolecular compounds
  • C10L1/1633—Hydrocarbons macromolecular compounds homo- or copolymers obtained by reactions only involving carbon-to carbon unsaturated bonds
  • C10L1/165—Hydrocarbons macromolecular compounds homo- or copolymers obtained by reactions only involving carbon-to carbon unsaturated bonds from compounds containing aromatic monomers
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/18—Organic compounds containing oxygen
  • C10L1/192—Macromolecular compounds
  • C10L1/195—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • C10L1/197—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds derived from monomers containing a carbon-to-carbon unsaturated bond and an acyloxy group of a saturated carboxylic or carbonic acid
  • C10L1/1973—Macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds derived from monomers containing a carbon-to-carbon unsaturated bond and an acyloxy group of a saturated carboxylic or carbonic acid mono-carboxylic
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B3/00—Engines characterised by air compression and subsequent fuel addition
  • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Definitions

• the present invention is concerned with improving the flow of fuels at low temperatures and improving pour point characteristics of middle distillates. More particularly, the invention relates to the preparation of improved low cold test hydrocarbon fuels, in particular heating oils and diesel fuels, kerosene, aviation turbo-jet fuels, and other fuels that are subject to low temperatures.
• the preferred class of pour depressants are alkylated polystyrene compounds utilized in conjunction with copolymers of ethylene and vinyl acetate. 7
• pour point depressants for lubricating oil.
• Paraflow, Santopour and Acryloid and their modifications They are prepared either by condensing aromatic compounds with long chain parafiins, such as wax, or by condensing olefinic esters. It is generally considered that these pour depressants are effective in that in cooling an additive-containing oil, the hydrocarbon chain of the additive becomes incorporated into the crystal lattice of the separated wax, while the other part of the pour depressant molecule prevents the crystals from adhering together to form a gel structure.
• the failure of these additives to be effective in middle distillates may at least in part be due to the basic difference in the composition between the wax in lubricating oils and that in middle distillate fuels.
• the petroleum distillate fuels in which the additive materials of the invention are employed consist of a major proportion, at least 95%, of liquid hydrocarbons boiling at temperatures between about 70 F. and about 750 F.
• These fuels include gasolines such as aviation, marine and automotive or motor gasolines, aviation turbo-jet fuels such as JP-l, JP-4 andJP 5 fuels, and diesel fuels such as marine, stationary and automotive diesel engine fuels.
• Aviation turbo-jet fuel consists of at least 95% of a 3,037,850 Patented one 5, 1 962 'r ce mixture of volatile hydrocarbons. It is defined by US. Military Specifications MIL-:F-5616 and MIL- -F-S 624 C. Its volatility is suchthat its endpoint does not exceed 572 F. Its viscosity is between 0.5 and 1.5 centistokes at 100 F. 7
• Diesel fuels as referred to in connection with the invention consist of at least 95% of a mixture of hydrocarbons boiling between 250 F. and 750 F. either by ASTM Method D-8656 when their end points do not exceed 600 F. or by ASTM Method D-158-54. Diesel fuels are defined byEASTM Specification D-975-53T and fall into grades 1D, 2D and 4D, in all of which the additive materials of the invention may be used. They have viscosities between 1.4 and 26.4 centistokes.
• liquid fuels in which the additive materials may be incorporated thus comprise at least 95% by weight of a mixture of hydrocarbons having a boiling range between the limits of 75 F. and 750 F. and a viscosity between the limits of 0.264 and 26.4 centistokes at 100 F.
• a synergistic efiect is secured by utilizing two different classes of pour depressants in conjunction with each other.
• the first class of pour depressants comprises alkylated polystyrene compounds while the second class of pour depressants to be utilized in conjunction with the first class of pour depressants comprises copolymers of ethylene and vinyl esters, particularly vinyl acetate.
• the first class of pour depressants comprising alkylated polystyrene compounds are prepared with certain olefins and have a critical composition.
• the olefin should have a molecular weight in the ranget200 to 250 and if it is a mixture at least- 95 mole percent of the olefins should have molecular weights individually in the range of 170 to 280.
• the alkylates of interest have the following structure:
• R is an alkyl group, straight or branched, containing 9 carbon atoms or less while R is a straight-chainalkyl group containing 10 carbon atoms or more, x is the number from 3 to 15 inclusive and y is 0.75 to 2.00.
• the process comprises the steps of dissolving the desired polystyrene in an inert solvent and heating the mixture until the polystyrene is completely in solution.
• the mixture is cooled to the desired reaction temperature at which time the nitrobenzene and the Friedel- Crafts catalyst is added.
• the alkylating agent is then groups.
• the alkylates are purified by well known techniques, among which is precipitation with methanol, dissolving'in' hexane and reprecitating several times with methanol or isopropanol. If desired, the
• the alkylated material may be dissolved in oil, washed with alkaline solutions, and the oil solution then steam stripped to result in the final product.
• the polystyrene starting material have an intrinsic viscosity within a range of about 0.2 to 1.0, preferably 0.8 to 1.5. These viscositiescorrespond to molecular weights within a range of from about 10,000 to 75,000, preferably 30,000 to 60,000 Staudinger. Since the amounts of the other reactants are based on the weight of the polystyrene, the amount of polystyrene used will depend upon restrictions such as equipment capacity, etc.
• the cryoscopic molecular Weight after alkylation was about 700 to 5,000; the intrinsic viscosity about 0.1 to 0.5.
• the 700 molecular weight comprises, in essence, a trimer containing three alkylated phenyl groups, whereas, the 3,000 molecular weight comprises, in essence, about eight alkylated phenyl
• the alkylation agent chosen for the preparation of the improved pour point depressants of this invention will be olefinic in nature and will preferably contain from 14 to :18 carbon atoms in a straight chain. Although dodecene1 through eicosylene and cracked Wax are used, any olefinic material having the above requirements maybe used. It is preferred that equimolar quantities of polystyrene and the alkylating agent be used, however, from 0.80 to 2.00 mols of alkylation agent per mol equivalent of polystyrene is operable.
• alkylated polystyrenes should be prepared wherein the olefin mixture has a molecular weight of about 224 (that of n-hexadecene).
• the polystyrenes should have a molecular weight within a range of from about 10,000 to 75,000, preferably 30,000 to 60,000 Staudinger. These molecular weights correspond to intrinsic viscosities within the range of from 0.2 to 2.0, preferably 0.8 to 1.0.
• the alkylating agent contemplated contains 12 to 20 carbon atoms in a straight chain.
• a chlorinated aromatic hydrocarbon is used as a solvent and a Friedel- Crafts catalyst in amounts varying between and by weight based on the weight of the polystyrene.
• the preferred catalyst modifier, nitrobenzene, is present in junction with the first class of pour depressants so as to secure synergistic results are copolymers of ethylene and a vinyl acetate. It is preferred that the parts by weight of ethylene in the copolymer be in the range from about 60 to 99% as. compared to parts by weight of vinyl ace: tate in'the range from about 40 to'about 1%.
• a very desirable ethylene-vinyl acetate copolymer contains from about 15 to 25% by weight of vinyl acetate, as for example, about 20% parts by weight of vinyl acetate.
• the molecular weights of the ethylene-vinyl acetate copolymer are critical and should be in the range from about 1,000 to 3,000, preferably, in the range from about 1,500 to 2,200.
• the molecular weights are determined by K. Rast s method (Ber. 55, 1051, 3727 (1922)).
• the ethylene-vinyl acetate copolymer as described above is used usually in a concentration in the range from about .001 to .5% by weight, preferably, in a concentration in the range from about .005 to .1% by weight.
• the low molecular weight copolymers may be prepared by any peroxide process. In some instances, it may be desirable to first prepare a higher average molecular weight polymerization product and then recover from that product material having a molecular weight within the range between about 1,000 and about 3,000.
• an eifective methodifor recovering the 1,000 to 3,000 molecular weight portion therefrom is to extract the product with a solvent such as normal heptane or methyl-ethyl ketone.
• a solvent such as normal heptane or methyl-ethyl ketone.
• Other methods for obtaining the low molecular weight materials include thermal degradation of the high molecular weight polymer or treatment of the high molecular weight polymer with ozone in order to break the polymer chains. Still other methods also useful will be apparent to those skilled in the art.
• a very desirable method is to conduct polymerization in a benzene solution using di-tertiary-butyl-perox- .ide as an initiator at a temperature in the range from about 280 to 340 F.
• the preferred temperature is about 300 F.
• the pressure is in the range from about 700 to-2,000 pounds, preferably, at about 800 pounds.
• the autoclave or similar equipment containing the solvent, initiator and vinyl acetate is purged about three times with nitrogen twice with ethylene and then charged with a sufficient amount of ethylene to yield the desired pressure when heated to the reaction temperature.
• the pour depressant agents have a cryoscopic molecular weight in the range from about 700 to 3,000 to 5,000 and an intrinsic viscosity in the range from about 0.1 to 0.5. These compounds are used a weight concentration of about 0.002 to 0.20. A somewhat more preferred concentration is inthe range from about 0.005 to 30.05 weight percent. A very desirable concentration to 'be used is in the range from about whenever the pressure drops by about p.s.i.g. Polymerization is considered complete when it is less than 50 p.s.i.g. pressure drop per hour. The product is stripped free of solid and untreated vinyl acetate under vacuum.
• Various amounts of the pour depressants of the present invention and the various salts were utilized in distillate fuels. A typical distillate fuel boiling in the range from 250 to 750 F. to which the present additives were added are middle distillate heating oils. These fuels are of commercial grade and have typical proper'tie's as follows: r a
• the present invention is concerned with the utilization of two classes of pour depressants in combination with each other.
• the amount of one pour depressant as compared to the other may vary from 25-75% to -25% although it is preferred that the ratio weight percent of one pour depressant as compared to the other vary from about 60-40 weight percent to 40-60 weight percent.
• a petroleum distillate fuel composition having an improved pour which comprises essentially a petroleum distillate fuel boiling in the range between about 250 F. and about 750 F. which has been improved with respect to pour point by the incorporation therein of a pour depressing efiective amount in the range from about .002 to .2% by weight of a pour depressant which consists in combination an alkylated polystyrene plus a copolymer of ethylene and vinyl acetate, said copolymer being characterized by having a molecular weight in the range from about 1000 to 3000 and being further characterized by containing from about 1% to 40% by weight of vinyl acetate in the copolymer, said alkylated polystyrene being chanacter'ized by having a molecular weight in the range from about 700 to about 3000 and being further characterized by having about one alkyl group containing from 12 to 20 carbon atoms per ring.
• composition as defined by claim 1 wherein the weight percentage of alkylated polystyrene present varies in the range from about .03 to .1 and wherein the amount of copolymer present varies in the range from about .03 to .05% by weight.
• composition as defined by claim 1 wherein the amount of said alkylated polystyrene as compared to said copolymer varies in the range from about 40 to 60% by weight.
• composition as defined by claim 1 wherein the pour depressant comprises about 50% by weight of said alkylated polystyrene and 5 0% by weight of said copolymer.
• composition as defined by claim 1 wherein the amount of said pour depressant added is in the range from about .01 wt. percent to .03 wt. percent.

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• Chemical & Material Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Engineering & Computer Science (AREA)
• Liquid Carbonaceous Fuels (AREA)
• Lubricants (AREA)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

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Cited By (13)

Citations (3)

• 1960
  • 1960-10-18 US US63244A patent/US3037850A/en not_active Expired - Lifetime
• 1961
  • 1961-09-22 GB GB34007/61A patent/GB940491A/en not_active Expired
  • 1961-10-03 DE DEE21751A patent/DE1232784B/de active Pending

Patent Citations (3)

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