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 OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/02—Liquid carbonaceous fuels essentially based on components consisting of carbon, hydrogen, and oxygen only
  • C10L1/023—Liquid carbonaceous fuels essentially based on components consisting of carbon, hydrogen, and oxygen only for spark ignition
• • 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 OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds

Definitions

• combustion noise is probably the most important because it indicates a reduced etficiency in utilizing available fuel energy and a resulting loss of power and mileage.
• control of combustion noise has been primarily a matter of suppressing spark knock, but the compression ratios of the newer engines have reached a point where other related phenomena have become serious. Wild ping, a sharp engine noise something like the noise of spark knock but randomly occurring, is likely if the deposits in the combustion chamber tend to glow and ignite the fuel mixture prematurely. Even less familiar problems now becoming prevalent include pounding or high speed rumble, and hot starting.
• Pounding is an engine noise which has been described as sounding like a broom handle dragged along a picket fence. It is encountered especially in the case of high compression engines, usually at fairly high speeds under moderate to heavy loads, and, like spark knock, is aggravated by increasing the compression ratio of the engine. Unlike spark knock however, raising the octane number of the gasoline will not prevent pounding.
• Hot starting is another phenomenon which has been encountered only in the newer very high compression engines. This is a noise like spark knock which occurs when restarting a warm engine.
• gasoline quality characteristics besides the avoidance of combustion irregularities have also recently become more critical.
• the gasoline should have a minimum tendency to form deposits not only in the combustion chamber but also in the fuel system.
• the carburetor and intake manifold in particular are critical in this respect because there the gasoline-air mixture is subjected to relatively high temperatures after the engine has been operated for some time and gums and resins are prone to form and interfere with the free flow of the fuel mixture and with the operation of the intake valves. This problem has been aggravated of late by the low profiles of the newer automobiles and the additional accessories in the engine compartment, such as air conditioning systems, which have considerably raised the normal engine compartment operating temperatures. 7
• gasoline Still another important characteristic of gasoline is the extent of its tendency to develop static electrical charges during handling and the resulting likelihood that a spark discharge will occur. The extreme danger of this can largely be avoided if the gasoline will conduct electricity to a substantial extent whereby the charges are dissipated to ground.
• Adding to the base gasoline a sufficient quantity of a high octane number hydrocarbon (together with a phosphorus compound) to raise the octane number to the same extent does not produce such a high quality of fuel.
• a sufficient quantity of a high octane number hydrocarbon (together with a phosphorus compound) to raise the octane number to the same extent does not produce such a high quality of fuel.
• an aromatic compound when an aromatic compound is added the quantity of carbon-containing deposit in the combustion chamber increases leading to a greater tendency towards surface ignition, i.e. wild ping and the gasoline also has a much greater tendency to cause pounding.
• adding an isoparatfinic material such as aviation alkylate or the like aggravates the hot starting problem. This is not difiicult to understand because, as described above, hot starting noise is caused by the spontaneous ignition and detonation of the fuel when compressed under warm engine starting conditions.
• a most interesting aspect of the composition of the invention is that the ether and the phosphorus compound cooperate to provide improved engine cleanliness and distribution of the gasoline heavy ends and relatively non-volatile additives among the cylinders.
• the phosphorus compounds in question have boiling points which are relatively high compared with the average of the gasoline as a whole; moreover, their viscosities are relatively high and in fact several of them are commercially used as plasticizers, for example tricresyl phosphate.
• the ether component is a better solvent for gums and other resinous deposits encountered in internal combustion engines than are the conventional hydrocarbon components, especially the non-aromatic ones, of the gasoline; this is probably because of the oxygenated character of both the gums and ethers.
• the intake manifold When a gasoline engine operated with the present gasoline composition is started the intake manifold is usually relatively cool and a substantial quantity of the ethers, even though they are relatively volatile, will appear in a liquid phase of gasoline on the walls of the intake manifold.
• the phosphorus compound softens or plasticizes any existing deposit making it easier for the ether to pull the deposits into the liquid whereby they are carried through to the combustion chamber where they are burned. Subsequently-formed deposits which may occur during an extended operation of the engine at normal operating temperatures are then taken into solution during the next warm up cycle of the engine.
• the improved distribution effect of the combination of ether and phosphorus compound is brought about by the increased tendency of the liquid phase of heavy ends of the gasoline to creep along the walls of the intake manifold toward the combustion chambers.
• the gasolineair mixture leaves the carburetor and enters the intake manifold it is, of course, partly in vapor form and partly in the form of dispersed liquid droplets.
• a substantial proportion of these liquid droplets collect as a liquid phase on the walls of the intake manifold. As this liquid phase moves toward the combustion chambers the lighter ends therein continue to evaporate.
• the relatively non volatile phosphorus compound of the composition of the invention has a higher surface tension than does the bulk gasoline and the relatively volatile ether has a lower surface tension than does the bulk gasoline; there is therefore a positive surface tension gradient in the direction from the carburetor to the combustion chambers. It has been found that under such circumstances a liquid phase will have a tendency to creep against the force of gravity; a commonly observed example of this phenomenon is the creeping of alcohol upwards along the vertical walls of wine glasses. The extent of the forces pulling the liquid film against gravity are directly proportional to the difference in the surface tensions of the components evaporating from the liquid film and the heavy ends left behind.
• the ethers of the present class have generally much lower surface tensions than gasoline hyrocarbons for example, the surface tension of diisopropyl ether at 25 C. is 17.3 dynes/cm. (Vogel, AL, J. Chem. 800., Part I, 616 (1948), as compared to about 26 dynes/cm. for gasoline hydrocarbons.
• the addition of both the ether and the phosphorus compound to gasoline hydrocarbons very substantially increases the surface tension gradient of the liquid along the walls of the intake manifold and thus increases its mobility, resulting in better distribution of the gasoline heavy ends and low volatility additives among the cylinders.
• the gasoline compositions of the invention have still another attribute of importance. This is their surprisingly low tendency to develop electrostatic charges. It is of course known that the danger of electrostatic charging can be reduced by incorporating in hydrocarbon liquids additives which increase the electrical conductivity of the liquid. Additives such as the chromium salt of C alkylsalicylic acids are known to be especially effective. It has been discovered that the ethers and phosphorus compounds of the present gasoline composition, which are unlike anything known to have been suggested before for this purpose, cooperate in an unexpected fashion to increase the electrical conductivity of gasoline. For example a base gasoline containing only gasoline boiling range hydrocarbons was measured and found to have an electrical conductivity of 17 ohmcmr The addition of 3 cc.
• the concentration of ether must be at least 2% by volume and preferably at least 4% by volume. Ether concentrations of more than 50% by volume are not only usually unnecessary but would be deleterious in a number of respects. It is preferred that no more than 25% and especially no more than 17% by Volume of the ether be present in the gasoline composition. Especially preferred ether concentrations are from about 6 to by volume.
• the phosphorus compound should be present at a concentration of at least 0.001% by weight and no more than 0.1% by weight. It is preferred that at least 0.01% by weight of the phosphorus compound be present. It is also preferred that no more than 0.06% by Weight be present.
• the concentration of the phosphorus compound is no less than 0.05 theory and no more than 0.6 theory.
• Preferred theory concentrations for the phosphorus compound are at least 0.2 theory and no more than 0.4 theory.
• a phosphorus compound designates the amount of phosphorus compound stoichiometrically equivalent with the lead in the lead antiknock agent all of the lead atoms and all of the phosphorus atoms are present in the same proportion as in the compound Pb (PO-).
• T theories of the phosphorus compound present
• M the number of gram mols of the phosphorus compound present
• A the number of gram atoms of lead in the lead anti-detonant present:
• the suitable ethers for practice of the invention are the branched chain di-lower-alkyl ethers containing a single oxygen atom, and at least 4 and no more than 8 carbon atoms, more especially 5 to 6 carbon atoms. Ethers outside this range are not only not useful in the present compositions but are, on the contrary, quite deleterious.
• dialkyl ethers which do not contain at least one branched chain alkyl group have such low octane numbers that their incorporation into gasoline, even in very small concentrations, could not be tolerated for use in modern high compression engines.
• ethers containing either less or more carbon atoms would not have suitable volatility to accomplish the purposes of the invention.
• At least one, and preferably both, of the two carbon atoms attached to the single oxygen atom of the ether should preferably be a secondary or a tertiary carbon atom.
• branched chain dialkyl ethers having 5 to 6 carbon atoms methyl tertiarybutyl ether, and especially diisopropyl ether are superior.
• Suitable ethers within the scope of the invention include ethyl tertiarybutyl ether, isopropyl, secondary butyl ether, isopropyl, tertiarybutyl ether, methyl tertiaryamyl ether, ethyl isopropyl ether, methyl secondary b-utyl ether and methyl tertiaryhexyl ether.
• An especially suitable ether component for the composition of the invention is a commercial diisopropyl ether product containing a minor amount of isopropyl alcohol and obtained by the reaction of propylene and water in a sulfuric acid medium, for example in accordance with the processes disclosed in Francis, U.S. 2,055,- 720, or in Oldershaw, US. 2,178,186.
• a typical product will contain a high concentration of diisopropyl ether, a smaller but substantial concentration of isopropyl alcohol, small concentrations each of ethyl isopropyl ether, ethyl alcohol, C to C propylene polymer, water and in some cases minute amounts of C to C hydrocarbons.
• the following are analyses of specific compositions which exemplify such suitable ether products:
• the organic phosphorus compound or mixture of compounds suitable for use in the gasoline composition of the invention must be hydrocarbon soluble and preferably contains only one phosphorus atom per molecule; it can be a phosphine, phosphine oxide, phosphite, phosphonite, phosphinite, phosphate, phosphonate, phosphinate or a sulfur analogue thereof.
• the organic radical or radicals of the phosphorus compound can be alkyl (acyclic or alicyclic) or aryl.
• any radical may also contain a halogen atom, in which case the halogen atom is preferably chlorine or bromine, and especially chlorine.
• cyclic radicals hydrocarbyl-substituted cyclic radicals are preferred. Phosphorus compounds having only radicals containing up to car-hon atoms are most useful, and it is preferred that at least one and preferably all the radicals contain at least 4, and especially at least 6 carbon atoms. It is also preferred that the phosphorus compound contain no sulfur.
• Particularly suitable are the trihydrocarbyl phosphates, trihydrocarbyl phosphites and trihydrocarbyl phosphines.
• Suitable phosphorus compounds for the practice of the invention are those having the formula:
• X is an oxygen or sulfur atom, that is, a chalcogen atom having an atomic number from 8 to 16, inclusive;
• R is a monovalent radical containing no atoms other than carbon, hydrogen, and halogen, no more than one halogen atom, and from 1 to 10 carbon atoms;
• a is a whole number from 0 to 1, inclusive
• b and c are Whole numbers from 0 to 3, inclusive, the sum of b and 0 being equal to 3.
• tricresyl phosphate tributyl phosphate, tributyl phosphite, diphenyl cresyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, triamyl thionophosphate, triphenyl phosphine, trimethyl phosphine oxide, tris(2-propyl) phosphite, bis(Z-propyl) 2-propylphosphonate, trimethyl phosphate, trimethyl phosphite, phenyl dimethylphosphinate, propyl dicresyl thiolophosphate, tris(3,3,S-trimethylcyclohexyl) phosphate, tris(2-chloroprop-yl) thionophosphate, diphenyl cresylphosphonite, dimethyl xylyl phosphate, dimethyl cresyl phosphate,
• the gasoline composition is most useful as fuel for automotive internal combustion spark ignition engines and as such the hydrocarbon components which comprise the major bulk of the gasoline can be straight run, thermally or catalytically cracked, thermally or catalytically reformed, or products of sulfuric acid or hydrofluor'ic acid alkylation of lower molecular weight olefins and isoparaifins, e.g. of butylenes and isobutane. Of course mixtures of such components are especially suitable. Automotive gasoline hydrocarbons have a boiling range of from about the boiling points of C to C hydrocarbons to about 450 F., and the mixtures thereof suitable as the hydrocarbon base of the composition of the invention will preferably have an ASTM method D 86 distillation range of from about 80 to 100 F. up to about 375 to 425 F.
• the composition of the invention will preferably contain an antiknock concentration of -a lead antiknock agent, i.e., a lead anti-detonant, such as a tetra-lower-alkyl lead compound, for example tetraethyl lead.
• a lead anti-detonant such as a tetra-lower-alkyl lead compound, for example tetraethyl lead.
• concentration of the lead antiknock agent is preferably at least 0.5 cc. per gallon and up to 6 cc. per gallon, more especially at least 1 cc. per gallon and no more than 3 cc. per gallon.
• a halohydrocarbon scavenger such as ethylene dibromide or a mixture of ethylene dibromide and ethylene dichloride is preferably added in conjunction therewith, especially in an amount of from about 1.0 to about 1.5 or 1.6 theories, 1.0 theory being the amount necessary to provide two atoms of halogen per atom of lead in the lead antiknock agent present.
• other antiknock agents such as iron carbonyl, dicyclopentadienyl iron, xylidene, N-methylaniline and the organo-manganese compounds of Brown et al., U.S.
• 2,818,417 especially methylcyclopentadienyl manganese tricarbonyl, or bis(cy- 8 clopentadienyl) manganese.
• Such compounds are suit ably used either as the only antiknock agent or preferably as a supplemental antiknoc'k agent with for example tetraethyl lead.
• additives suitably used if desired in the composition of the invention include the various anti-icing agents such as N-C -alkylpropylenediamine and dimethylformamide; combustion chamber deposit modifiers such as glycol esters of boric acid for example isopropyl 2-methyl-2,4-pentanediol borate, 2-methyl-2,4 pentanediol monoacid borate, bis(l,1,3 trimethyl trimethyleneoxy) boric oxide, and the like; anti-oxidants such as N,N'-disecondarybutylphenylenediamine, 2,6 ditertiarybutyl-4- methylphenol, 4,4 methylene bis(2,6 ditertiarybutylphenol), and the like; corrosion inhibitors such as polymerized linoleic acids and N,C-disu-bstiuted imidazolines; metal deactivators such as N,N-disalicyla1-1,2-propanediamine; and dyes, silicone oils, and the like.
• composition of the invention is the following:
• Petroleum gasoline hydrocarbons 90% v. Diisopropyl ether (the commercial product obtained by reaction of water and propylene described and identified aboveas D 10% v. Tetraethyl lead 2.8 cc./gal. Ethylene dibromide 0.5 theory. Ethylene dichloride 1.0 theory. Tricresyl phosphate 0.3 theory.
• N-C -alkyl-1,3-propanediamine 30 p.p.m. (Wt.).
• This composition had an ASTM research method octane number of 102.0 (Wiese scale, i.e., isooctane+0.l6 cc. TEL/gal), an ASTM motor method octane number of 92.5, an ASTM distillation of from about 100 F. to about 400 F.
• composition of the invention which may also contain various other minor components as described above, include:
• Petroleum gasoline hydrocarbons 88% v. Diisopropyl ether 12% v. Tetraethyl lead 2 cc./ gal. Octyl diphenyl phosphate 0.2 theory.
• a gasoline fuel for spark ignition internal combustion engines comprising a major amount of gasoline boiling range hydrocarbons, a minor eifective anti-detonant amount of an organo-lead antiknock agent, at least 2% and up to 50% by volume of a branched chain di-loweralkyl ether containing a single oxygen atom and at least 4 and no more than 8 carbon atoms wherein at least one of the carbon atoms attached to the single oxygen atom is selected from the group consisting of secondary and tertiary carbon atoms, and from about 0.001% to about 0.1% by Weight of a hydrocarbon soluble organic phosphorus compound selected from the group consisting of trihydrocarbyl phosphates, trihydrocarbyl phosphites, and trihydrocarbyl phosphines, each hydrocarbyl group of which is a monovalent organic radical containing from 1 10 to 10 carbon atoms and containing no atoms other than carbon and hydrogen, the concentration of said phosphorus compound being from
• a gasoline fuel for spark ignition internal combustion engines comprising a major amount of gasoline boiling range hydrocarbons, a minor effective anti-detonant amount of tetraethyl lead, from about 2% to about 25% by volume of a branched chain alkyl other selected from the group consisting of diisopropyl ether and methyl tertiarybutyl ether, and from about 0.001% to about 0.1% by weight of a hydrocarbon-soluble organic phosphorus compound selected irom the group consisting of trihydrocarbyl phosphates, trihydrocarbyl phosphites, and trihydrocarbyl phosphines, each hydnocarbyl group of which is a monovalent organic radical containing from 4 to 10 carbon atoms and containing no atoms other than carbon and hydrogen, the theory concentration of said phosphorus compound being from about 0.05 to about 0.6.
• a gasoline fuel for spark ignition internal combustion engines comprising a major amount of gasoline boiling range hydrocarbons, a minor effective anti-detonant amount of tetraethyl lead, from about 2% to about 25% by volume of diisopropyl ether, and from about 0.001% to about 0.1% by Weight of a hydrocarbon-soluble organic phosporus compound selected from the group consisting of trihydrocarbyl phosphates, trihydrocarbyl phosphites and trihydrocarbyl phosphines, each hydrocarbyl group of which is a monovalent organic radical containing from 4 to 10 carbon atoms and containing no atoms other than carbon and hydrogen, the theory conecentration of said phosphorus compound being from about 0.1 to about 0.4.

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• Liquid Carbonaceous Fuels (AREA)

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Cited By (5)

Citations (14)

• 1958
  • 1958-07-01 US US745837A patent/US3052528A/en not_active Expired - Lifetime
• 1959
  • 1959-06-29 CH CH7506659A patent/CH396513A/de unknown
  • 1959-06-29 DK DK232359AA patent/DK118536B/da unknown

Patent Citations (14)

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